Microdomain elements of airway smooth muscle in calcium regulation and cell proliferation.

Airway remodeling manifested by hyperplasia of airway smooth muscle cells (ASMCs) and other structural and functional changes is a pathological condition in asthma not addressed by current treatment. Ca2+ signaling is crucial for ASMC proliferation. Inositol-1,4,5-trisphosphate receptor (IP3R) and ryanodine receptor (RyR) mediate Ca2+ release from endoplasmic reticulum/sarcoplasmic reticulum (ER/SR). Upon sensing the depletion of Ca2+ in ER/SR, stromal interaction molecule 1 (STIM1) aggregates and redistributes at the microdomain of ER/SR-plasma membrane (PM) and activates Orai1, a component of the store-operated Ca2+ (SOC) channels, to initiate Ca2+ influx. The STIM1/Orai1-mediated SOC entry is the main cause of a sustained intracellular calcium ([Ca2+]i) elevation, which is different from a transient rise of [Ca2+]i mediated by IP3R and RyR. Extended-synaptotagmin 1 (E-Syt1) is recruited to the ER/SR-PM junction and anchors to the PM lipid phosphatidylinositol-4,5-bisphosphate (PI(4,5)P2) in a SOC-dependent manner. The subsequent strengthening of the ER/SR-PM connection by E-Syt1 facilitates the phosphatidylinositol (PI) transfer protein, Nir2, to supplement PI, a PI(4,5)P2 substrate, for the generation of IP3 and the propagation of Ca2+ signaling. Calcineurin and nuclear factor of activated T cells are the downstream signaling factors of elevated [Ca2+]i contributing to ASMC proliferation. Mitochondrial Ca2+ uptake/efflux, mitochondrial fission/fusion and mitochondrial-ER/SR coupling also play important roles in modulating [Ca2+]i and ASMC proliferation. Together, these pathways and mechanisms represent new therapeutic targets for airway remodeling. The present review provides an overview of our current understanding of the mechanisms of ASMC proliferation involving Ca2+ and highlights potential directions to control airway remodeling in asthma.

Gun trauma and ophthalmic outcomes.

PurposeThis retrospective cohort study assesses the visual outcomes of patients who survive gunshot wounds to the head.MethodsThe Elmhurst City Hospital Trauma Registry and Mount Sinai Data Warehouse were queried for gun trauma resulting in ocular injury over a 16-year period. Thirty-one patients over 16 years of age were found who suffered a gunshot wound to the head and resultant ocular trauma: orbital fracture, ruptured globe, foreign body, or optic nerve injury. Gun types included all firearms and air guns. Nine patients were excluded due to incorrect coding or unavailable charts. Statistical analysis was performed using a simple bivariate analysis (χ2).ResultsOf the 915 victims of gun trauma to the head, 27 (3.0%) sustained ocular injuries. Of the 22 patients whose records were accessible, 18 survived. Eight of the 18 surviving patients (44%) suffered long-term visual damage, defined as permanent loss of vision in at least one eye to the level of counting fingers or worse. Neither location of injury (P=0.243), nor type of gun used (P=0.296), nor cause of gun trauma (P=0.348) predicted visual loss outcome. The Glasgow Coma Scale eye response score on arrival to the hospital also did not predict visual loss outcome (P=0.793).ConclusionThere has been a dearth of research into gun trauma and even less research on the visual outcomes following gun trauma. Our study finds that survivors of gun trauma to the head suffer long-term visual damage 44% of the time after injury.

Effects of the 3D bone-to-implant contact and bone stiffness on the initial stability of a dental implant: micro-CT and resonance frequency analyses.

This study investigated the effects of bone stiffness (elastic modulus) and three-dimensional (3D) bone-to-implant contact ratio (BIC%) on the primary stabilities of dental implants using micro-computed tomography (micro-CT) and resonance frequency analyses. Artificial sawbone models with five values of elastic modulus (137, 123, 47.5, 22, and 12.4 MPa) comprising two types of trabecular structure (solid-rigid and cellular-rigid) were investigated for initial implant stability quotient (ISQ), measured using the wireless Osstell resonance frequency analyzer. Bone specimens were attached to 2 mm fibre-filled epoxy sheets mimicking the cortical shell. ISQ was measured after placing a dental implant into the bone specimen. Each bone specimen with an implant was subjected to micro-CT scanning to calculate the 3D BIC% values. The similarity of the cellular type of artificial bone to the trabecular structure might make it more appropriate for obtaining accurate values of primary implant stability than solid-bone blocks. For the cellular-rigid bone models, the ISQ increased with the elastic modulus of cancellous bone. The regression correlation coefficient was 0.96 for correlations of the ISQ with the elasticity of cancellous bone and with the 3D BIC%. The initial implant stability was moderately positively correlated with the elasticity of cancellous bone and with the 3D BIC%.

Managing vascular risk in hypertension with a focus on microalbuminuria: attitude and practices.

INTRODUCTION: Elevated blood pressure is a principal risk factor for cardiovascular and renal diseases. Early detection and adequate treatment of hypertension are essential components in the primary prevention of these end-stage events. Microalbuminuria is recognised as an early marker of renal disease and increased cardiovascular risk. Screening alerts physicians to implement timely intervention strategies to delay disease progression and minimise consequent complications. Although the value and significance of microalbuminuria screening has been widely documented, its use is still suboptimal. METHODS: Survey forms were sent to randomly-selected general practitioners in Singapore to capture their self-reported attitudes and practices regarding microalbuminuria screening in the management of hypertension. RESULTS: Results from this survey revealed that microalbuminuria screening was practised by 88 percent of the physicians surveyed; however, only 56 percent of hypertensive patients without risk factors were screened. Quantitative analysis of urine samples was the preferred screening method of 90 percent of the physicians surveyed. CONCLUSION: A concerted effort should be made to address the lack of public awareness on the importance of screening for microalbuminuria. Continuing medical education should also emphasise the usefulness of surrogate markers in the therapeutic prevention of end-organ damage in hypertensive patients. There is also a need to form a consensus guideline on microalbuminuria screening, to aid in the standardisation of practice.

PGE suppresses excessive anti-IgE induced cysteinyl leucotrienes production in mast cells of patients with aspirin exacerbated respiratory disease.

BACKGROUND: Aspirin causes bronchospasm in patients with aspirin exacerbated respiratory disease (AERD). The contribution of mast cells to the increased cysteinyl-leucotrienes (cys-LTs) detected in AERD patients is however not defined. AIMS OF THE STUDY: Effects of prostaglandin (PG) E(2) and inhibitors of cyclooxygenase (COX) and lipoxygenase (LO) pathways on mediator release from cultured mast cells of normal subjects, aspirin tolerant asthma (ATA) and AERD patients were compared to better define the role of mast cells in AERD. METHODS: Mast cells were cultured from peripheral blood progenitors and were activated by anti-IgE. Histamine, PGD(2) and cys-LTs released were then determined. RESULTS: Basal release of all three mediators was similar in all subjects. Although the release of all three mediators was increased by anti-IgE, mast cells from AERD patients produced significantly more cys-LTs (6.9 +/- 2.0 ng/10(6) cells) than normal and ATA subjects (2.3 +/- 0.8 and 1.7 +/- 0.5 ng/10(6) cells, respectively). While COX and LO pathway inhibitors did not affect anti-IgE induced histamine release, they significantly suppressed the production of PGD(2) and cys-LTs, respectively, in all patients. PGE(2) significantly enhanced anti-IgE induced histamine and PGD(2) release from mast cells of normal subjects but not those of ATA and AERD patients. In contrast, PGE(2) suppressed only anti-IgE induced cys-LTs release from mast cells of AERD patients. CONCLUSION: We speculate that overproduction of cys-LTs is unique to mast cells of AERD patients and is particularly sensitive to suppression by PGE(2). Consequently reduction of PGE(2) production by aspirin removes this endogenous control of cys-LTs overproduction, resulting in asthma attack.

Microalbuminuria prevalence study in hypertensive patients with type 2 diabetes mellitus in Singapore.

INTRODUCTION: Microalbuminuria is a marker of increased cardiovascular morbidity and mortality. It represents the earliest clinical evidence of diabetic nephropathy. Its early detection allows for implementation of individually-tailored cardiovascular risk reduction management programmes. Despite this, information on the prevalence of microalbuminuria in hypertensive patients with type 2 diabetes mellitus in Singapore is limited. METHODS: The Microalbuminuria Prevalence Study (MAPS) assessed the prevalence of macroalbuminuria and microalbuminuria in consecutively-screened hypertensive adult patients with type 2 diabetes mellitus in ten Asian countries. This paper presents the results of a sub-analysis of data from patients in Singapore. RESULTS: Singapore contributed seven percent of the overall enrolment into MAPS; a total of 499 patients were enrolled and 388 constituted the per-protocol population (patients with bacteriuria and haematuria were excluded). Overall, the prevalence of diabetic kidney disease was high. In our study population, 23.5 percent of patients had macroalbuminuria (95 percent confidence interval [CI] 21.3-25.6), and 48.5 percent of patients had microalbuminuria (95 percent CI 45.9-51.0). Only 28.1 percent (95 percent CI 25.8-30.4) of patients were normoalbuminuric. Associated factors were poor glycaemic control and poor blood pressure control. CONCLUSION: The high prevalence (72 percent) of microalbuminuria and macroalbuminuria found in hypertensive patients with type 2 diabetes mellitus in Singapore is a cause for concern. These findings highlight the need to screen for microalbuminuria and better manage hypertensive patients with type 2 diabetes mellitus, if we are to avoid a major increase in end-stage renal disease.

An alarmingly high prevalence of diabetic nephropathy in Asian type 2 diabetic patients: the MicroAlbuminuria Prevalence (MAP) Study.

AIM/HYPOTHESIS: Microalbuminuria represents the earliest clinical evidence of diabetic nephropathy and is a marker of increased cardiovascular morbidity and mortality. Its early detection allows the implementation of individualised and aggressive intervention programmes to reduce cardiovascular risk factors. There is limited information on the prevalence of microalbuminuria among hypertensive type 2 diabetic patients in Asia. METHODS: This cross-sectional epidemiological study aimed to assess the prevalence of microalbuminuria and macroalbuminuria among consecutively screened hypertensive type 2 diabetic adult patients in 103 centres in 10 Asian countries or regions. Predictive factors for microalbuminuria and macroalbuminuria were characterised using a stepwise logistic regression model. RESULTS: A total of 6,801 patients were enrolled and 5,549 patients constituted the per-protocol population (patients with bacteriuria and haematuria were excluded). The prevalence of microalbuminuria was 39.8% (39.2-40.5; 95% CI) and the prevalence of macroalbuminuria was 18.8% (18.2-19.3; 95% CI). Only 11.6% of the patients had systolic and diastolic blood pressure below the 130/80 mm Hg target. In the multivariate analyses, the predictive factors for the presence of microalbuminuria were age, BMI, systolic blood pressure and ethnic origin. The highlighted predictive factors for the presence of macroalbuminuria were age, sex, ethnic origin, BMI, duration of diabetes, presence of diabetic complications, intake of diuretics, intake of calcium channel blockers, diastolic and systolic blood pressure. CONCLUSIONS/INTERPRETATION: The high prevalence (58.6%) of micro or macroalbuminuria observed in these patients is alarming and indicates an impending pandemic of diabetic cardiovascular and renal diseases in Asia with its potential economic consequences.

Pentaglobin in steroid-resistant severe acute respiratory syndrome.

SETTING: The treatment of severe acute respiratory syndrome (SARS) is at best controversial, although there is considerable anecdotal experience to show the benefits of corticosteroid therapy for selected patients. Some patients deteriorate relentlessly despite treatment with antibiotic, corticosteroid and mechanical ventilation. OBJECTIVE: To attempt to determine the clinical efficacy of pentaglobin, an IgM-enriched immunoglobulin preparation, on 12 severe SARS patients who continued to deteriorate despite corticosteroid and ribavirin therapy. DESIGN: Retrospective analysis of daily quantitative and radiographic data on the cohort in a regional teaching hospital. RESULTS AND CONCLUSION: There was significant improvement in radiographic scores, when compared with day 1, on days 5, 6 and 7 (P < 0.05) after commencement of pentaglobin treatment. Similarly, there was significant improvement in oxygen requirement, when compared with day 1, on days 6 and 7 (P < 0.05) after commencement of pentaglobin treatment. There were no reported adverse events attributable to pentaglobin administration. Ten patients made an uneventful recovery after treatment. One elderly man died from cardiorespiratory arrest despite clinical and radiological improvement, and another patient is making good progress. Pentaglobin is safe and probably effective in the treatment of steroid-resistant SARS. A double-blind placebo-controlled study should therefore be considered.

Anti-inflammatory effects of high-dose montelukast in an animal model of acute asthma.

BACKGROUND: Asthmatic inflammation is mediated by a network of cytokines, chemokines and adhesion molecules. Corticosteroids are the only effective agents available to control asthmatic inflammation. We investigated the effect of high-dose montelukast (MK), a selective cysteinyl leukotriene receptor 1 antagonist, on mediators of airway inflammation. OBJECTIVE: The aim of this study was to determine the effect of a 3-day course of high-dose MK on mediators of airway inflammation induced by a single allergen challenge in sensitized mice. METHODS: Ovalbumin (OVA)-sensitized BALB/c mice were treated with 25 mg/kg of MK or saline intravenously for 3 days. On the third day, a single inhalation challenge with OVA was given. Cellular infiltration was assessed in the bronchoalveolar lavage (BAL) and in the lung. Expression of IL-4, IL-5, IL-13 and eotaxin in the BAL, and the lung was determined. Serum IL-5 and total IgE was measured. IL-5 and eotaxin mRNA expression in the lung was determined. Finally, eotaxin and VACM-1 expression in the lung was assessed by immunohistochemistry. RESULTS: MK reduced the number of eosinophils in the BAL by > 90%. There was also significant reduction in IL-5 in the BAL, lung and the serum, and IL-5 mRNA expression in the lung. IL-4 level in the lung and BAL, and IL-13 level in the lung also significantly decreased. Serum IgE level and lung VCAM-1 expression was also significantly lower in treated animals, but eotaxin protein and mRNA expression in the lung remained unchanged. CONCLUSION: MK exerts its anti-inflammatory effect through the suppression of T helper type-2 (Th2) cytokines. The use of high-dose MK as an anti-inflammatory agent in acute asthma should be further explored.

Approximating large convolutions in digital images.

Computing discrete two-dimensional (2-D) convolutions is an important problem in image processing. In mathematical morphology, an important variant is that of computing binary convolutions, where the kernel of the convolution is a 0-1 valued function. This operation can be quite costly, especially when large kernels are involved. We present an algorithm for computing convolutions of this form, where the kernel of the binary convolution is derived from a convex polygon. Because the kernel is a geometric object, we allow the algorithm some flexibility in how it elects to digitize the convex kernel at each placement, as long as the digitization satisfies certain reasonable requirements. We say that such a convolution is valid. Given this flexibility we show that it is possible to compute binary convolutions more efficiently than would normally be possible for large kernels. Our main result is an algorithm which, given an m x n image and a k-sided convex polygonal kernel K, computes a valid convolution in O(kmn) time. Unlike standard algorithms for computing correlations and convolutions, the running time is independent of the area or perimeter of K, and our techniques do not rely on computing fast Fourier transforms. Our algorithm is based on a novel use of Bresenham's (1965) line-drawing algorithm and prefix-sums to update the convolution incrementally as the kernel is moved from one position to another across the image.

Nasal glomus tumors: report of two cases with emphasis on immunohistochemical features and differential diagnosis.

We describe 2 cases of nasal glomus tumor that presented as nasal polyps. Grossly, each of the polypectomy specimens consisted of small fragments of polypoid soft tissue with glistening mucosa. Histopathological examination of each of the specimens showed sheets and nests of monomorphic round cells intimately associated with capillary-sized blood vessels. The tumor cells were strongly cytoplasmic positive for vimentin, smooth-muscle specific actin, muscle-specific actin, and CD34. Collagen IV showed pericellular positivity. Nasal glomus tumors are extremely rare and represent less than 0.5% of nasal nonepithelial tumors. Nasal polyps are common surgical pathological specimens, with the majority of nasal polyps being inflammatory polyps or a respiratory epithelial proliferation. Histologically, many nasal polyps show vascular proliferation with an inflammatory cell infiltrate, which may be confused with the rare glomus tumor. In addition, other nasal vascular tumors, in particular nasal hemangiopericytoma and neural tumors, may histologically mimic nasal glomus tumors.

Mutation of the MENIN gene in sporadic pancreatic endocrine tumors.

Pancreatic endocrine tumors occur both sporadically and as part of the multiple endocrine neoplasia type 1 (MEN1) syndrome. MEN1 is an autosomal dominant disease characterized by parathyroid hyperplasia, pancreatic endocrine tumors, and pituitary adenomas. The MEN1 gene called MENIN maps to chromosome 11q13 and is thought to function as a tumor suppressor gene. We previously demonstrated loss of heterozygosity (LOH) at 11q13 in approximately 40% of sporadic pancreatic endocrine tumors and hypothesize that MENIN is involved in the development of these tumors. Thirty-one sporadic pancreatic endocrine tumors were analyzed for mutation of MENIN by nonradioactive single-stranded conformation polymorphism. Twelve mutations were detected in 31 sporadic pancreatic endocrine tumors (34%). Twelve of these 31 tumors previously demonstrated loss of heterozygosity at 11q13. Of the tumors with LOH, seven contained mutations of the MENIN gene (58%). The majority of the MENIN mutations occurred within exon 2. Two independent mutations in MENIN were detected in a gastrinoma that also revealed LOH, leading to the possibility of another tumor suppressor gene locus at 11q13. Mutations were present in both benign and malignant pancreatic endocrine tumors, suggesting that a MENIN gene mutation is a frequent and early event in the tumorigenesis. The high incidence of truncating mutations in tumors with LOH at 11q13 support the hypothesis that MENIN is a tumor suppressor gene.

Protection against diabetes by MHC heterozygosity and reversal by cyclophosphamide.

In type I diabetes in both rodents and humans, genetic susceptibility to disease is strongly linked to MHC class II alleles. In some cases, however, certain class II alleles provide resistance to disease. To examine this effect in a well-defined system, we studied double transgenic mice expressing influenza hemagglutinin (HA) on pancreatic islet beta cells and an HA-specific TCR on CD4 T cells. On a susceptible B10.D2 background, 70% of double transgenic mice develop an early-onset spontaneous autoimmune diabetes. MHC heterozygosity induced variable protection from diabetes, depending on the specific nonpermissive allele, but insulitis was invariably present. Autoreactive T cells retained the ability to induce diabetes because cyclophosphamide treatment induced diabetes in 81% of young MHC(d/b) transgenic mice, although the effect was diminished in older mice. Most importantly, treatment induced higher IFN-gamma/IL-4 ratios among CD4 T cells, suggesting a strong shift toward Th1 development, perhaps through direct effects on patterns of gene expression in CD4 T cells.

Inhibition of HT-29 human colon cancer growth under the renal capsule of severe combined immunodeficient mice by an analogue of 1,25-dihydroxyvitamin D3, DD-003.

An analogue of 1,25-dihydroxyvitamin D3, 22(S)-24-homo-26,26,26,27,27,27-hexafluoro-1 alpha,22,25-trihydroxyvitamin D3 (DD-003), showed 10-fold greater inhibiting effect than 1,25-dihydroxyvitamin D3 on the growth of HT-29 human colonic adenocarcinoma cells in culture. To examine the anticancer activity of DD-003 in vivo, a fibrin clot of HT-29 cells was prepared with fibrinogen and thrombin and implanted under the renal capsule of the severe combined immunodeficient mouse. Starting 7 days after implantation of HT-29 tumor, mice were given 3 micrograms/kg body weight of DD-003 or the vehicle i.p. every other day for 5 times. The HT-29 tumor grew rapidly in control mice; malignant growth was clearly observed with mitosis, massive tumor angiogenesis, and invasion into normal kidney tissue. Tumors in DD-003 treated mice were smaller with less invasion compared to the control. Administration of DD-003 inhibited growth of HT-29 tumor by 63%. Serum calcium concentrations and body weights of the treated mice were similar to those of the control. DD-003 inhibited growth of HT-29 tumor in a dose-dependent manner over the range of 0.1-10 micrograms/kg body weight, with no increase of serum calcium concentration observed at any dose level. When DD-003 was withdrawn after 2 weeks of treatment, tumor growth resumed. Since chemosensitivity tested by the subrenal capsule assay correlates well with clinical response, DD-003 may be clinically applicable in procedures such as postsurgical chemotherapy of colon cancer.

Utility of immediate on-site cytopathological procurement and evaluation in fine needle aspiration biopsy of head and neck masses.

The utility of on-site microscopic evaluation of fine needle aspirates (FNAs) of the head and neck was assessed by comparing the diagnostic yield in 336 specimens obtained with immediate on-site cytopathological procurement and evaluation to that achieved in 548 cases performed without immediate on-site evaluation. Three hundred six (91%) of 336 immediate evaluation specimens were adequate for cytopathologic diagnosis, compared to 391 (71%) of 548 specimens not evaluated immediately (P < .001, chi-squared test). The higher satisfactory rate in immediate evaluation cases was related primarily to 1. immediate reaspiration of the masses until sufficient cytopathologic material was obtained for diagnosis; and 2. optimal specimen preparation. It is concluded that immediate on-site cytopathological procurement and evaluation of fine needle aspirates of head and neck masses is a valuable practice which assures a higher yield of adequate specimens compared to biopsies taken without immediate evaluation. The technique of immediate on-site evaluation of FNAs is discussed and a cost-benefit analysis of immediate on-site evaluation of FNAs is presented.

Pathologic evaluation of gynecologic specimens obtained with the cavitron ultrasonic surgical aspirator (CUSA).

Eighty consecutive gynecologic specimens obtained with the Cavitron Ultrasonic Surgical Aspirator (CUSA) were evaluated pathologically. Fifty specimens were obtained during intraabdominal tumor debulking and thirty resulted from ablation of lower genital tract lesions. In 98% of intraabdominal specimens and in 93% of patients with a history of lower genital tract lesions, the CUSA material permitted an accurate diagnosis. Although artifacts related to cellular thermal injury were ubiquitous, nearly all cases were interpretable with a combination of cytologic (smear, Cytospin, Millipore filter) and histologic (cell block) preparations. Squamous intraepithelial lesions (SILs) of the lower genital tract were better preserved in cell block preparations, whereas intraabdominal adenocarcinomas were readily diagnosed by both cytologic and histologic techniques. Accurate grading of SILs and exclusion of invasion were difficult in some cell blocks due to the fragmented and superficial nature of the samples. Cytologic preparations of lower genital tract lesions often consisted of thick uninterpretable fragments and degenerated single cells that contributed little to the evaluation of SILs. We conclude that examination of CUSA specimens confirmed the surgical removal of pathologic tissue in 96% of cases, but an exact diagnosis of SILs was not possible in all cases.

[Autologous bone marrow transplantation after purging by low molecular weight natural tumor suppressor in long-term marrow culture in vitro: report on 2 cases].

In the light of high sensitivity of fresh bone marrow blast progenitor of human myeloid leukemia (L-CFU) towards the action of low molecular tumor suppressor isolated from human fetal liver, massive bone marrow was aspirated from the patients suffering from acute myeloid leukemia at the stage of first complete remission and cocultured in a long-term bone marrow culture system for 9 days. The purged marrow cells were then re-infused into the patients after preconditioning with large doses of cytotoxin and acute ionizing irradiation. Hematopoiesis was reconstituted due to the autologous transplantation in vivo. After the autologous bone marrow transplantation without chemical treatment, two cases are still survival with the time of more than 17 and 15 months respectively.

Gastroduodenal mucosa in uraemia: endoscopic and histological correlation and prevalence of helicobacter-like organisms.

This study aimed to determine the prevalence of endoscopic and histological gastroduodenitis as well as helicobacter-like organisms in patients with end stage renal failure undergoing maintenance dialysis treatment. A total of 322 out of 422 patients in our dialysis programme underwent endoscopy and gastroduodenal biopsy specimens were taken from 260. Endoscopic gastroduodenitis occurred in 158 (49%). Histological gastritis occurred in the gastric body or antrum in 134 patients (52%) and duodenitis in 52 (21%). There was no correlation between endoscopic and histological gastritis in contrast to a significant correlation for duodenitis. Helicobacter-like organisms occurred in the body or antrum in 81 (31%). Their presence was associated with gastritis--in particular acute and acute on chronic gastritis rather than chronic gastritis. Patients with gastritis were significantly older than those without (p less than 0.001) and had lower basal and peak acid outputs.