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1.
S Afr J Surg ; 61(1): 1-6, 2023 Mar.
Article in English | MEDLINE | ID: mdl-37052281

ABSTRACT

BACKGROUND: Posterior retroperitoneoscopic adrenalectomy (PRA) is purported to be superior to the laparoscopic transperitoneal approach (LA) in patients with a select spectrum of benign adrenal pathologies. Advantages attributed to the technique include minimal blood loss, shortened operative times, and decreased postoperative pain, explained anatomically by the direct access to the adrenal gland. Reduced workspace is a limitation. METHODS: A retrospective review of 22 consecutive PRAs performed in a single centre between 1 September 2016 and 30 October 2020 is presented. Two experienced laparoscopic surgeons operated on all patients after acquiring the technique at international centres. Suitable candidates were carefully pre-selected. Non-benign pathology, high vascularity, body mass index (BMI) ≥ 45 kg/m2 and anatomical concerns on prior computed tomography (CT) imaging were exclusion criteria. RESULTS: Twenty-two PRAs were performed for a spectrum of benign adrenal pathologies. Twenty-one surgeries (95%) were completed. A single case of pheochromocytoma required conversion. The procedure was safe, a minor postoperative complication (pneumaturia) occurred in one case, and the mortality rate was 0%. Median operative time (80 minutes) is comparable to other reported series in the literature, with a modest linear descending tendency noted over the study period. Underlying pathology influenced operative times. Pheochromocytomas proved to be most challenging and required careful preoperative evaluation. CONCLUSION: The PRA procedures performed at Tygerberg Academic Hospital were safe and reproducible in a select group of cases with benign adrenal pathology. Endocrine surgeons proficient with laparoscopic techniques should be encouraged to use the PRA approach when encountering adrenal neoplasms that fit the criteria.


Subject(s)
Adrenal Gland Neoplasms , Laparoscopy , Humans , Adrenalectomy/methods , South Africa , Adrenal Gland Neoplasms/diagnostic imaging , Adrenal Gland Neoplasms/surgery , Laparoscopy/methods , Retrospective Studies
2.
S Afr J Surg ; 59(2): 69a-69c, 2021 Jun.
Article in English | MEDLINE | ID: mdl-34212578

ABSTRACT

SUMMARY: This report describes an extremely unusual cause of acute pancreatitis. It highlights the value of cross-sectional imaging, in the absence of alcohol and gallstone aetiology, to establish a diagnosis and direct management. Computed tomography (CT) revealed a duodenal jejunal intussusception. A benign inflammatory fibroid tumour, acting as a lead point, was surgically resected and the patient made an unremarkable recovery without further episodes of acute pancreatitis.


Subject(s)
Intussusception , Leiomyoma , Pancreatitis , Acute Disease , Humans , Intestinal Polyps/complications , Intestinal Polyps/diagnosis , Intestinal Polyps/surgery , Intussusception/diagnosis , Intussusception/etiology , Intussusception/surgery , Pancreatitis/diagnosis , Pancreatitis/etiology
3.
S Afr J Surg ; 58(3): 154-159, 2020 Sep.
Article in English | MEDLINE | ID: mdl-33231009

ABSTRACT

BACKGROUND: Extra-levator abdominoperineal resection (ELAPE) performed in the prone jack-knife position is a new technique in the developing world. Literature on the outcomes of ELAPE in a developing country context is scarce. The objective was to assess early outcomes after ELAPE in the prone jack-knife position, and to compare outcomes of patients who underwent the abdominal part of the procedure performed laparoscopically with an open group, at a tertiary institution in Cape Town. METHODS: Records of patients who underwent ELAPE for rectal adenocarcinoma from February 2011 to February 2017 at Tygerberg Hospital were retrospectively reviewed. Variables of interest included staging, rate of circumferential resection margin involvement (CRMI), intraoperative tumour perforation (IOP), perineal wound complications, early postoperative morbidity, length of intensive care unit (ICU) stay, duration of postoperative hospital stay and 30-day mortality rate. RESULTS: 52 patients (median age: 59 years) were included in the analysis. CRMI was evident in 16% (8/49) of patients and IOP in 6% (3/52). Perineal wound complications occurred in 32% (16/50) of patients. Median length of ICU and postoperative hospital stay was 3 days and 7 days, respectively. Overall morbidity was 47% (24/51) and the 30-day mortality rate was 3% (2/52). A significant difference in length of hospital stay was evident between the open and laparoscopic groups (11.5 days vs 6 days). CONCLUSION: Prone abdominoperineal resection (APR), ELAPE, and laparoscopic ELAPE are acceptable and feasible procedures for patients with rectal cancer in the developing world, with outcomes being comparable to those determined in the developed world.


Subject(s)
Adenocarcinoma/surgery , Laparoscopy , Patient Positioning , Proctectomy , Prone Position , Rectal Neoplasms/surgery , Adenocarcinoma/mortality , Adenocarcinoma/pathology , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Rectal Neoplasms/mortality , Rectal Neoplasms/pathology , Retrospective Studies , South Africa , Treatment Outcome
4.
S Afr J Surg ; 57(2): 20-26, 2019 Jun.
Article in English | MEDLINE | ID: mdl-31342680

ABSTRACT

BACKGROUND: In South Africa, 42.0% of adult females and 13.5% of adult males are classified as obese, the highest recorded numbers in Sub-Saharan Africa. Metabolic surgery has been proven to be a safe and effective treatment, yet due to demand on government resources has only been performed to a limited extent in public hospitals. The aim of this study was to describe the safety and efficacy of performing metabolic surgery at a single academic hospital in South Africa. METHOD: This was a single centre retrospective review of 57 metabolic surgery procedures performed from October 2011 to September 2017 at Tygerberg Hospital, Cape Town, South Africa. The primary outcome was safety including mortality and adverse events. Secondary outcomes included effect of surgery on weight and diabetes resolution. RESULTS: A total of 57 patients underwent laparoscopic metabolic surgery, of which 44 (83.0%) were female with a mean age (standard deviation) of 42.8 (8.0) years. Fifty-six patients (98%) underwent Roux-and-Y gastric bypass and one (2%) had a sleeve gastrectomy performed. There were no mortalities and overall morbidity was 14.0%, with 3 (5.3%) classified as major and 5 (8.8%) as minor. The follow-up rate at 1 year was 100%. Mean preoperative body mass index (BMI) was 58.8 kg/m2, and comorbidities included hypertension (59.6%), Type 2 Diabetes (42.1%), and dyslipidaemia (36.8%). There were no conversions to open surgery and at one year the mean (95% confidence interval) percentage excess body mass index loss was 50.4% (44.0-56.8%). CONCLUSION: Metabolic surgery can be performed safely in the public sector in South Africa, with short-term safety and efficacy outcomes comparable to international reports. Larger scale studies are needed to determine long-term outcomes and cost-effectiveness.


Subject(s)
Bariatric Surgery , Obesity, Morbid/surgery , Adult , Body Mass Index , Comorbidity , Female , Humans , Male , Obesity, Morbid/epidemiology , South Africa/epidemiology
5.
Afr Health Sci ; 14(3): 585-92, 2014 Sep.
Article in English | MEDLINE | ID: mdl-25352876

ABSTRACT

BACKGROUND: Food borne illnesses and food poisoning are cause for concern globally. The diseases are often caused by food contamination with pathogenic bacteria due largely to poor sanitary habits or storage conditions. OBJECTIVES: Prevalence of some bacteria on cleaned and sanitised food contact surfaces from eight convenience food plants in Gauteng (South Africa) was investigated with the view to evaluate the efficacy of the cleaning methods used with such food contact surfaces. METHODS: The microbial load of eight convenience food manufacturing plants was determined by sampling stainless steel food contact surfaces after they had been cleaned and sanitised at the end of a day's shift. Samples were analysed for Total Plate Count (TPC), Escherichia coli, Salmonella species, Staphylococcus aureus and Listeria species. RESULTS: Results showed that 59 % of the total areas sampled for TPC failed to comply with the legal requirements for surfaces, according to the Foodstuffs, Cosmetics and Disinfectants Act (< 100 cfu.cm(-2)). S. aureus and Salmonella were not detected, but Listeria was detected in 23 % and E. coli in 1.3 % of the samples. Fifty percent (50 %) of the plants applied conventional cleaning methods for cleaning and sanitation and 50 % used the low-pressure foam (LPF) method. There was significant difference (P ≤ 0.05) between the mean TPC values of the conventional cleaning method (14 358.82) compared to that of LPF method (2 386.51) but no significant difference (P > 0.05) in terms of Listeria species isolates obtained from both cleaning methods. The LPF method proved to be the superior cleaning option for lowering TPC counts. CONCLUSION: Regardless of cleaning method used, pathogens continued to flourish on various surfaces, including dry stainless steel, posing a contamination hazard for a considerable period depending on the contamination level and type of pathogen. Intensive training for proper chemical usage and strict procedural compliance among workers for efficient cleaning procedures is recommended.


Subject(s)
Bacteria/drug effects , Disinfectants/pharmacology , Equipment Contamination , Food Contamination/prevention & control , Sanitation/methods , Bacteria/isolation & purification , Colony Count, Microbial , Food Microbiology , Humans , South Africa
6.
Eur J Vasc Endovasc Surg ; 38(3): 267-72, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19570690

ABSTRACT

OBJECTIVES: To review a single-centre experience with stent-graft treatment of penetrating carotid artery injuries and long-term follow-up. METHODS: All stable patients with carotid artery injuries presenting between August 1998 and February 2009 were considered for endovascular treatment. Patients were selected based on clinical and radiological criteria and data were prospectively collected. Follow-up was conducted clinically, angiographically and by telephonic contact. Endpoints were stroke, death and any other stent-graft-related complications. RESULTS: A total of 128 patients were treated, of whom only 19 were selected for endovascular management. The recorded technical success rate was 100%, with one early stroke and one non-stent-graft-related procedural death. A further four patients were lost to follow-up. The remaining 14 patients had a mean follow-up of nearly 4 years. No stent-graft-related late deaths, strokes or other complications were reported, although one instance of late stent-graft occlusion was documented. CONCLUSION: Endovascular management of penetrating carotid artery injuries is safe and the long-term outcomes justify a more liberal application of this technique in selected patients.


Subject(s)
Aneurysm, False/surgery , Arteriovenous Fistula/surgery , Carotid Artery Injuries/surgery , Wounds, Stab/surgery , Adolescent , Adult , Aneurysm, False/diagnostic imaging , Aneurysm, False/mortality , Arteriovenous Fistula/diagnostic imaging , Arteriovenous Fistula/mortality , Blood Vessel Prosthesis , Blood Vessel Prosthesis Implantation/adverse effects , Blood Vessel Prosthesis Implantation/instrumentation , Blood Vessel Prosthesis Implantation/mortality , Carotid Artery Injuries/diagnostic imaging , Carotid Artery Injuries/mortality , Follow-Up Studies , Humans , Male , Middle Aged , Prospective Studies , Radiography , Stents , Stroke/etiology , Stroke/prevention & control , Time Factors , Treatment Outcome , Wounds, Stab/diagnostic imaging , Wounds, Stab/mortality , Young Adult
7.
Eur J Vasc Endovasc Surg ; 36(1): 56-62, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18356085

ABSTRACT

OBJECTIVE: To review our management of penetrating innominate artery injuries by open and endovascular techniques. METHODS: Data regarding patient demography, clinical presentation, investigations, associated injuries, pathology, management, complications and mortality, were collected on patients treated at a single centre over 18 years. RESULTS: 39 innominate artery injuries were treated. There were 36 men and three women, with a mean age of 27 years (range 18-49). Thirty-eight injuries were due to stabwounds and one was the result of a gunshot wound. The most common clinical presentations were shock (47%) and haematoma(42%). Twenty-three patients had associated injuries. The most common pathology was false aneurysm in 21 patients followed by 13 actively bleeding injuries, 4 arteriovenous fistulas and 1 arterial occlusion. Thirty-four patients underwent surgical and five endovascular repair. Overall survival was 79%. The stroke rate for surviving patients was 6%. Patients treated with endovascular stenting had shorter hospital and intensive care unit stays than those treated with surgery. CONCLUSIONS: Innominate artery injuries have high rates of morbidity and mortality. A vascular surgical approach with pre-operative angiography, when possible and careful surgical planning by a dedicated team promotes better surgical results. Endovascular and hybrid procedures can become the method of choice when treating stable patients.


Subject(s)
Brachiocephalic Trunk/surgery , Vascular Surgical Procedures , Wounds, Gunshot/surgery , Wounds, Stab/surgery , Adult , Anastomosis, Surgical , Blood Vessel Prosthesis , Blood Vessel Prosthesis Implantation/instrumentation , Brachiocephalic Trunk/diagnostic imaging , Brachiocephalic Trunk/injuries , Female , Humans , Male , Middle Aged , Patient Selection , Radiography , Retrospective Studies , Risk Assessment , Stents , Sternum/surgery , Treatment Outcome , Vascular Surgical Procedures/adverse effects , Vascular Surgical Procedures/instrumentation , Wounds, Gunshot/diagnostic imaging , Wounds, Gunshot/mortality , Wounds, Stab/diagnostic imaging , Wounds, Stab/mortality
8.
Cell Motil Cytoskeleton ; 63(1): 14-28, 2006 Jan.
Article in English | MEDLINE | ID: mdl-16317718

ABSTRACT

Profilins are actin binding proteins, which also interact with polyphosphoinositides and proline-rich ligands. On the basis of the genome sequence, three diverse profilin homologues (PFN) are predicted to exist in Caenorhabditis elegans. We show that all three isoforms PFN-1, PFN-2, and PFN-3 are expressed in vivo and biochemical studies indicate they bind actin and influence actin dynamics in a similar manner. In addition, they bind poly(L-proline) and phosphatidylinositol 4,5-bisphosphate micelles. PFN-1 is essential whereas PFN-2 and PFN-3 are nonessential. Immunostainings revealed different expression patterns for the profilin isoforms. In embryos, PFN-1 localizes in the cytoplasm and to the cell-cell contacts at the early stages, and in the nerve ring during later stages. During late embryogenesis, expression of PFN-3 was specifically detected in body wall muscle cells. In adult worms, PFN-1 is expressed in the neurons, the vulva, and the somatic gonad, PFN-2 in the intestinal wall, the spermatheca, and the pharynx, and PFN-3 localizes in a striking dot-like fashion in body wall muscle. Thus the model organism Caenorhabditis elegans expresses three profilin isoforms and is the first invertebrate animal with tissue-specific profilin expression.


Subject(s)
Caenorhabditis elegans/metabolism , Profilins/metabolism , Actin Cytoskeleton/drug effects , Actins/chemistry , Animals , Caenorhabditis elegans/embryology , Cell Movement , Cell Survival , Embryo, Nonmammalian/metabolism , In Vitro Techniques , Models, Biological , Molecular Sequence Data , Organ Specificity , Peptides/chemistry , Profilins/genetics , Profilins/pharmacology , Profilins/physiology , Proline/chemistry , Protein Binding , Protein Isoforms/metabolism , Rabbits
9.
Clin Cancer Res ; 8(6): 1871-7, 2002 Jun.
Article in English | MEDLINE | ID: mdl-12060630

ABSTRACT

PURPOSE: We undertook a systematic approach to identify breast cancer (BC) marker genes with molecular assays and evaluated these marker genes for the detection of minimal residual disease in peripheral blood mononuclear cells (PBMCs). EXPERIMENTAL DESIGN: We used serial analysis of gene expression to identify a range of genes that were expressed in BC but absent in the expression profiles of blood and bone marrow cells. Next, we evaluated a panel of four marker genes (p1B, PS2, CK19, and EGP2) by real-time quantitative PCR in 103 PBMC samples from patients with metastatic BC (stage III/IV) and in 96 PBMC samples from healthy females. RESULTS: Increased marker gene expression of at least one marker was seen in 33 of 103 patients. Using quadratic discriminant analysis including all four marker genes, we determined a discriminant value with 29% positivity in the BC patient group that did not yield false positive results among the healthy females. CONCLUSIONS: Real-time PCR for the simultaneous expression of multiple cancer-specific genes may ensure the specificity required for the clinical application of mRNA expression-based assays for occult tumor cells.


Subject(s)
Biomarkers, Tumor/metabolism , Breast Neoplasms/blood , Gene Expression Profiling , Neoplasm, Residual/blood , Neoplastic Cells, Circulating/metabolism , Antigens, Neoplasm/genetics , Antigens, Neoplasm/metabolism , Biomarkers, Tumor/genetics , Biopsy , Bone Marrow/metabolism , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Cell Adhesion Molecules/genetics , Cell Adhesion Molecules/metabolism , DNA Primers/chemistry , Epithelial Cell Adhesion Molecule , Female , Humans , Immunoenzyme Techniques , Keratins/genetics , Keratins/metabolism , Neoplasm, Residual/genetics , Neoplasm, Residual/pathology , Neoplastic Cells, Circulating/pathology , Polymerase Chain Reaction , Proteins/genetics , Proteins/metabolism , Sensitivity and Specificity , Trefoil Factor-1 , Tumor Suppressor Proteins
10.
Neural Comput ; 14(5): 1115-47, 2002 May.
Article in English | MEDLINE | ID: mdl-11972910

ABSTRACT

The Bayesian evidence framework has been successfully applied to the design of multilayer perceptrons (MLPs) in the work of MacKay. Nevertheless, the training of MLPs suffers from drawbacks like the nonconvex optimization problem and the choice of the number of hidden units. In support vector machines (SVMs) for classification, as introduced by Vapnik, a nonlinear decision boundary is obtained by mapping the input vector first in a nonlinear way to a high-dimensional kernel-induced feature space in which a linear large margin classifier is constructed. Practical expressions are formulated in the dual space in terms of the related kernel function, and the solution follows from a (convex) quadratic programming (QP) problem. In least-squares SVMs (LS-SVMs), the SVM problem formulation is modified by introducing a least-squares cost function and equality instead of inequality constraints, and the solution follows from a linear system in the dual space. Implicitly, the least-squares formulation corresponds to a regression formulation and is also related to kernel Fisher discriminant analysis. The least-squares regression formulation has advantages for deriving analytic expressions in a Bayesian evidence framework, in contrast to the classification formulations used, for example, in gaussian processes (GPs). The LS-SVM formulation has clear primal-dual interpretations, and without the bias term, one explicitly constructs a model that yields the same expressions as have been obtained with GPs for regression. In this article, the Bayesian evidence framework is combined with the LS-SVM classifier formulation. Starting from the feature space formulation, analytic expressions are obtained in the dual space on the different levels of Bayesian inference, while posterior class probabilities are obtained by marginalizing over the model parameters. Empirical results obtained on 10 public domain data sets show that the LS-SVM classifier designed within the Bayesian evidence framework consistently yields good generalization performances.


Subject(s)
Artificial Intelligence , Bayes Theorem , Least-Squares Analysis , Normal Distribution
11.
IEEE Trans Neural Netw ; 12(4): 809-21, 2001.
Article in English | MEDLINE | ID: mdl-18249915

ABSTRACT

The Bayesian evidence framework is applied in this paper to least squares support vector machine (LS-SVM) regression in order to infer nonlinear models for predicting a financial time series and the related volatility. On the first level of inference, a statistical framework is related to the LS-SVM formulation which allows one to include the time-varying volatility of the market by an appropriate choice of several hyper-parameters. The hyper-parameters of the model are inferred on the second level of inference. The inferred hyper-parameters, related to the volatility, are used to construct a volatility model within the evidence framework. Model comparison is performed on the third level of inference in order to automatically tune the parameters of the kernel function and to select the relevant inputs. The LS-SVM formulation allows one to derive analytic expressions in the feature space and practical expressions are obtained in the dual space replacing the inner product by the related kernel function using Mercer's theorem. The one step ahead prediction performances obtained on the prediction of the weekly 90-day T-bill rate and the daily DAX30 closing prices show that significant out of sample sign predictions can be made with respect to the Pesaran-Timmerman test statistic.

12.
Mol Cell Biol ; 20(21): 8209-19, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11027290

ABSTRACT

We deduced the structure of the mouse profilin II gene. It contains five exons that can generate four different transcripts by alternative splicing. Two transcripts encode different profilin II isoforms (designated IIa and IIb) that have similar affinities for actin but different affinities for polyphosphoinositides and proline-rich sequences. Profilins IIa and IIb are also present in humans, suggesting that all mammals have three profilin isoforms. Profilin I is the major form in all tissues, except in the brain, where profilin IIa is most abundant. Profilin IIb appears to be a minor form, and its expression is restricted to a limited number of tissues, indicating that the alternative splicing is tightly regulated. Western blotting and whole-mount in situ hybridization show that, in contrast to the expression of profilin I, the expression level of profilin IIa is developmentally regulated. In situ hybridization of adult brain sections reveals overlapping expression patterns of profilins I and IIa.


Subject(s)
Alternative Splicing , Contractile Proteins , Microfilament Proteins/biosynthesis , Microfilament Proteins/chemistry , Amino Acid Sequence , Animals , Base Sequence , Blotting, Western , Brain/metabolism , Dose-Response Relationship, Drug , Exons , Expressed Sequence Tags , Humans , In Situ Hybridization , Introns , Ligands , Mice , Microfilament Proteins/genetics , Molecular Sequence Data , Phosphatidylinositol 4,5-Diphosphate/pharmacology , Profilins , Protein Binding , Protein Isoforms , Rats , Reverse Transcriptase Polymerase Chain Reaction , Sequence Homology, Amino Acid , Time Factors , Tissue Distribution , Transcription, Genetic
13.
J Biol Chem ; 275(46): 36143-51, 2000 Nov 17.
Article in English | MEDLINE | ID: mdl-10945997

ABSTRACT

Proteins of the Ena/VASP family are implicated in processes that require dynamic actin remodeling such as axon guidance and platelet activation. In this work, we explored some of the pathways that likely regulate actin dynamics in part via EVL (Ena/VASP-like protein). Two isoforms, EVL and EVL-I, were highly expressed in hematopoietic cells of thymus and spleen. In CD3-activated T-cells, EVL was found in F-actin-rich patches and at the distal tips of the microspikes that formed on the activated side of the T-cells. Like the other family members, EVL localized to focal adhesions and the leading edge of lamellipodia when expressed in fibroblasts. EVL was a substrate for the cAMP-dependent protein kinase, and this phosphorylation regulated several of the interactions between EVL and its ligands. Unlike VASP, EVL nucleated actin polymerization under physiological conditions, whereas phosphorylation of both EVL and VASP decreased their nucleating activity. EVL bound directly to the Abl, Lyn, and nSrc SH3 domains; the FE65 WW domain; and profilin, likely via its proline-rich core. Binding of Abl and nSrc SH3 domains, but not profilin or other SH3 domains, was abolished by cAMP-dependent protein kinase phosphorylation of EVL. We show strong cooperative binding of two profilin dimers on the polyproline sequence of EVL. Additionally, profilin competed with the SH3 domains for binding to partially overlapping binding sites. These data suggest that the function of EVL could be modulated in a complex manner by its interactions with multiple ligands and through phosphorylation by cyclic nucleotide dependent kinases.


Subject(s)
Actins/metabolism , Carrier Proteins/chemistry , Cell Adhesion Molecules/chemistry , Contractile Proteins , Cyclic AMP-Dependent Protein Kinases/metabolism , Cytoskeletal Proteins , Phosphoproteins/chemistry , Proteins/metabolism , src Homology Domains , Amino Acid Sequence , Animals , Binding, Competitive , Biopolymers/metabolism , CD4-Positive T-Lymphocytes/cytology , CD4-Positive T-Lymphocytes/enzymology , CD4-Positive T-Lymphocytes/metabolism , Cells, Cultured , Fibroblasts/metabolism , Fluorescent Antibody Technique , Lymphocyte Activation , Mice , Microfilament Proteins/metabolism , Molecular Sequence Data , Phosphorylation , Profilins , Proline/metabolism , Protein Binding , Proteins/chemistry , Proteins/genetics , Rats , Transfection
14.
Breast Cancer Res Treat ; 56(3): 219-31, 1999 Aug.
Article in English | MEDLINE | ID: mdl-10573113

ABSTRACT

Detection of tumor cells in blood and bone marrow is increasingly used for the staging of patients with breast cancer and to evaluate the presence of tumor cells in peripheral blood progenitor cell collections to be used after high-dose therapy. We evaluated the sensitivity and specificity of three different methods for detection of tumor cells among non-tumor tissue. An immunocytochemical assay using antibodies directed against epitopes of the cytokeratin-19 (CK19) protein and two RNA-based methods: reverse transcriptase polymerase chain reaction (RT-PCR) and Nucleic Acid Sequence-Based Amplification (NASBA) for the same target gene were tested. With all the three methods, false-positive results were observed when peripheral blood mononuclear cells (PBMC) of healthy volunteers were tested. There was no concordance between the RNA-based assays and the immunocytochemical assay. The false-positive results in the RNA-based assays may be due to 'illegitimate expression' of epithelial genes in normal PBMC. The false-positive results in the immunocytochemical assay resulted from background staining of monocytes and granulocytes. This study demonstrates that CK19 is not a suitable target to detect the presence of breast tumor tells in PBMC. To reliably detect circulating tumor cells with RNA methods, the selection of suitable target genes is required, which are highly expressed in tumors but not at all in normal cells of blood and bone marrow. Genes with such characteristics may be identifiable with novel differential display techniques.


Subject(s)
Breast Neoplasms/blood , Breast Neoplasms/chemistry , Neoplastic Cells, Circulating/chemistry , RNA, Messenger/analysis , Reverse Transcriptase Polymerase Chain Reaction/methods , Sequence Analysis, RNA/methods , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Humans , Immunohistochemistry , Keratins/biosynthesis , Neoplastic Cells, Circulating/metabolism , Neoplastic Cells, Circulating/pathology , Nucleic Acid Amplification Techniques , RNA, Messenger/genetics , Sensitivity and Specificity
15.
FEBS Lett ; 447(2-3): 257-63, 1999 Mar 26.
Article in English | MEDLINE | ID: mdl-10214957

ABSTRACT

Profilin II dimers bind the (GP5)3 peptide derived from VASP with an affinity of approximately 0.5 microM. The resulting profilin II-peptide complex overcomes the combined capacity of thymosin beta4 and profilin II to inhibit actin nucleation and restores the extent of filament formation. We do not observe such an effect when barbed filament ends are capped. Neither can profilin I, in the presence of the peptide, promote actin polymerization during its early phase consistent with a lower affinity. Since a Pro17 peptide-profilin II complex only partially restores actin polymerization, the glycine residues in the VASP peptide appear important.


Subject(s)
Actins/chemistry , Actins/metabolism , Cell Adhesion Molecules/chemistry , Cell Adhesion Molecules/metabolism , Contractile Proteins , Microfilament Proteins/chemistry , Microfilament Proteins/metabolism , Phosphoproteins/chemistry , Phosphoproteins/metabolism , Amino Acid Sequence , Animals , Cattle , Dimerization , In Vitro Techniques , Microfilament Proteins/pharmacology , Models, Molecular , Molecular Sequence Data , Peptide Fragments/chemistry , Peptide Fragments/metabolism , Profilins , Protein Binding , Protein Conformation , Rabbits , Thymosin/pharmacology
16.
AIDS ; 12(14): 1763-9, 1998 Oct 01.
Article in English | MEDLINE | ID: mdl-9792376

ABSTRACT

OBJECTIVE: As HIV infection most commonly occurs via a mucosal surface, and as gastrointestinal symptoms are very frequent among HIV-infected patients, we investigated the functional properties of residual lymphocytes in the duodenal mucosa from HIV-infected individuals. DESIGN: Duodenal biopsies and blood samples were obtained from 19 HIV-infected patients [Centers for Disease Control and Prevention (CDC) stage III] and from 19 controls. METHODS: Phenotypic analysis of lymphocytes was performed by flow cytometry and/or immunocytochemistry. Interferon gamma (IFN-gamma), interleukin (IL) 4 and immunoglobulin secretions were analysed by enzyme-linked immunospot techniques. The phenotype of cytokine-producing cells was analysed by flow cytometry. RESULTS: The proportions of duodenal T lymphocytes from HIV-infected patients spontaneously secreting IFN-gamma or IL-4 were not lower than those from healthy controls. In patients with a high intestinal mucosal viral load, they were higher than in controls (P < 0.05). The proportions of immunoglobulin-secreting cells were significantly raised in HIV-infected patients for the three main isotypes. CONCLUSIONS: T- and B-cell populations of the intestinal mucosa remain functional or are even activated in patients with AIDS, even when the numbers of both mucosal and circulating CD4+ lymphocytes are strongly decreased.


Subject(s)
B-Lymphocytes/immunology , Duodenum/immunology , HIV Infections/immunology , Intestinal Mucosa/immunology , T-Lymphocyte Subsets/immunology , Adult , Biopsy , Cytokines/metabolism , Female , Flow Cytometry , HIV Infections/virology , Humans , Immunity, Mucosal , Immunoenzyme Techniques , Immunoglobulins/biosynthesis , Immunohistochemistry , Immunophenotyping , Intestinal Mucosa/virology , Male , Middle Aged , Viral Load
17.
Gut ; 42(5): 643-9, 1998 May.
Article in English | MEDLINE | ID: mdl-9659157

ABSTRACT

BACKGROUND: Cytokines secreted by intestinal T lymphocytes probably play a critical role in regulation of the gut associated immune responses. AIMS: To quantify interferon gamma (IFN-gamma) and interleukin 4 (IL-4) secreting cells (SC) among human intraepithelial (IEL) and lamina propria (LPL) lymphocytes from the duodenum and right colon in non-pathological situations and in the absence of in vitro stimulation. PATIENTS: Duodenal and right colonic biopsy specimens were obtained from patients with no inflammation of the intestinal mucosa. METHODS: Intraepithelial and lamina propria cell suspensions were assayed for numbers of cells spontaneously secreting IFN-gamma and IL-4 by a two site reverse enzyme linked immunospot technique (ELISPOT). RESULTS: The relatively high proportion of duodenal lymphocytes spontaneously secreting IFN-gamma (IEL 3.6%; LPL 1.9%) and IL-4 (IEL 1.3%; LPL 0.7%) contrasted with the very low numbers of spontaneously IFN-gamma SC and the absence of spontaneously IL-4 SC among peripheral blood mononuclear cells. In the basal state, both IFN-gamma and IL-4 were mainly produced by CD4+ cells. Within the colon, only 0.2% of IEL and LPL secreted IFN-gamma in the basal state, and 0.1% secreted IL-4. CONCLUSIONS: Compared with peripheral lymphocytes substantial proportions of intestinal epithelial and lamina propria lymphocytes spontaneously secrete IFN-gamma and/or IL-4. These cytokines are probably involved in the normal homoeostasis of the human intestinal mucosa. Disturbances in their secretion could play a role in the pathogenesis of gastrointestinal diseases.


Subject(s)
Colon/immunology , Duodenum/immunology , Interferon-gamma/metabolism , Interleukin-4/metabolism , T-Lymphocytes/metabolism , Adult , Aged , CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , Enzyme-Linked Immunosorbent Assay/methods , Epithelium/immunology , Flow Cytometry , Humans , Intracellular Fluid/immunology , Middle Aged , Statistics, Nonparametric
18.
Ann Oncol ; 9(12): 1269-76, 1998 Dec.
Article in English | MEDLINE | ID: mdl-9932154

ABSTRACT

BACKGROUND: Many solid tumors commonly metastasize to the bone marrow and the presence of tumor cells in the bone marrow is associated with a poor prognosis. Detection of tumor cells in the bone marrow has been reported to be important to determine the prognosis of newly diagnosed patients and may be helpful in deciding whether or not systemic treatment is indicated. PATIENTS AND METHODS: The majority of the studies focus on the detection of tumor cells in non-tumor tissue using immunocytochemistry and antibodies directed against epitopes of epithelial genes. Recently, the sensitive reverse-transcriptase polymerase chain reaction (RT-PCR) has been employed for the detection of tumor cells in bone marrow, using mRNA transcribed from epithelial genes as targets for RT-PCR. RESULTS: In some studies, encouraging results were reported when RT-PCR was used to detect expression of epithelial genes, but in many others frequent false-positive results were observed. These may results from the 'illegitimate expression' of epithelial genes in cells of non-epithelial tissues, such as bone marrow. CONCLUSIONS: Micrometastases in bone marrow can be detected with some sensitivity by antibodies directed against epithelial genes. RNA based methods, using epithelial genes as target for amplification, are less reliable. To improve these methods, a systematic approach is required to identify genes which are highly expressed in solid tumors and completely silent in blood and bone marrow of healthy individuals. Novel techniques, e.g., 'sequential analysis of gene expression (SAGE), are now available that allow such an endeavor.


Subject(s)
Biomarkers, Tumor/analysis , Bone Marrow Examination/methods , Bone Marrow/pathology , Gene Amplification , Neoplasm Metastasis/diagnosis , Neoplastic Stem Cells/pathology , RNA, Messenger/analysis , RNA, Neoplasm/analysis , Reverse Transcriptase Polymerase Chain Reaction , Biomarkers, Tumor/genetics , Clinical Trials as Topic , Epithelial Cells/pathology , Forecasting , Gene Expression , Humans , Immunohistochemistry , Neoplasm Proteins/genetics , Neoplasm Staging , Neoplastic Cells, Circulating , Prognosis , Sensitivity and Specificity
19.
EMBO J ; 16(3): 484-94, 1997 Feb 03.
Article in English | MEDLINE | ID: mdl-9034331

ABSTRACT

We present a study on the binding properties of the bovine profilin isoforms to both phosphatidylinositol 4,5-bisphosphate (PIP2) and proline-rich peptides derived from vasodilator-stimulated phosphoprotein (VASP) and cyclase-associated protein (CAP). Using microfiltration, we show that compared with profilin II, profilin I has a higher affinity for PIP2. On the other hand, fluorescence spectroscopy reveals that proline-rich peptides bind better to profilin II. At micromolar concentrations, profilin II dimerizes upon binding to proline-rich peptides. Circular dichroism measurements of profilin II reveal a significant conformational change in this protein upon binding of the peptide. We show further that PIP2 effectively competes for binding of profilin I to poly-L-proline, since this isoform, but not profilin II, can be eluted from a poly-L-proline column with PIP2. Using affinity chromatography on either profilin isoform, we identified profilin II as the preferred ligand for VASP in bovine brain extracts. The complementary affinities of the profilin isoforms for PIP2 and the proline-rich peptides offer the cell an opportunity to direct actin assembly at different subcellular localizations through the same or different signal transduction pathways.


Subject(s)
Cell Adhesion Molecules/metabolism , Cell Cycle Proteins , Contractile Proteins , Cytoskeletal Proteins , Drosophila Proteins , Fungal Proteins/metabolism , Microfilament Proteins/metabolism , Phosphatidylinositol 4,5-Diphosphate/metabolism , Phosphoproteins/metabolism , Amino Acid Sequence , Animals , Binding Sites , Binding, Competitive , Blotting, Western , Brain/metabolism , Cattle , Circular Dichroism , Dimerization , Electrophoresis, Polyacrylamide Gel , Microfilament Proteins/chemistry , Molecular Sequence Data , Peptide Fragments/metabolism , Peptides/metabolism , Profilins , Protein Conformation , Protein Structure, Tertiary , Spleen/metabolism
20.
Angle Orthod ; 66(4): 265-72, 1996.
Article in English | MEDLINE | ID: mdl-8863961

ABSTRACT

Certain craniofacial characteristics were identified on the lateral cephalograms of 40 untreated subjects with shallow mandibular antegonial notches and 40 subjects with deep notches. Subjects with shallow notches demonstrated more on the morphological characteristics usually associated with horizontal mandibular growth patterns than did subjects with deep notches, and their mandibles were positioned more protrusively. In general, the mandibles of the shallow notch subjects proved to be longer than mandibles of the deep notch subjects. On average, mandibles with deep notches showed greater gonial angles, deeper posterior ramus notch depths, and larger occlusal plane inclinations. The total anterior facial height of shallow notch subjects was much smaller than that of the deep notch subjects. The maxillae in deep notch subjects were more retrusive in relation to the cranial base when compared with the shallow notch subjects. A discriminant analysis was used to determine which combinations of variables were most consistently related to either deep or shallow mandibular antegonial notches. Eighty percent (80%) of the cases were classified correctly as deep or shallow notch cases by means of this discriminant function.


Subject(s)
Cephalometry , Face , Facial Bones/anatomy & histology , Mandible/pathology , Skull/anatomy & histology , Adolescent , Child , Chin/pathology , Dental Occlusion , Discriminant Analysis , Female , Humans , Incisor/pathology , Jaw Relation Record , Linear Models , Male , Malocclusion/pathology , Mandible/growth & development , Maxilla/pathology , Vertical Dimension
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