Bile Salt Anion Sorption by Polymeric Resins: Comparison of a Functionalized Polyacrylamide Resin with Cholestyramine.

Cholestyramine and a cross-linked polyacrylamide resin with lateral alkyl quaternary ammonium groups (QPDA12) were used to study their ability to bind several bile salt anions (including the cholate, glycocholate, taurocholate, and chenodeoxycholate), individually and competitively, from phosphate buffer solutions at room temperature. The latter resin showed high affinities for all the bile salt anions examined, while cholestyramine exhibited a high affinity only for the more hydrophobic chenodeoxycholate. However, for the binding with cholestyramine, cooperative effects were more pronounced, leading to the enhancement of sorption at higher concentrations. The Langmuir equation and its modified versions were used in the interpretation of both individual and competitive binding of bile salts. The data from competitive binding studies indicated that the presence of the tightly bound chenodeoxycholate did not significantly diminish the ability of QPDA12 resin to bind cholate. However, for cholestyramine, the sorption of chenodeoxycholate increased the relative binding affinity for the more hydrophilic cholate, revealing a novel "cooperative" effect involving different bile salt anions. The latter results suggest that the observed higher affinity of QPDA12 is brought about predominantly through the hydrophobic interactions with the pendant alkyl groups rather than with the resin backbone. Copyright 2000 Academic Press.

Herpes simplex esophagitis in immunocompetent hosts.

Over four months, three cases of biopsy-proven herpes simplex esophagitis were seen at Centre hospitalier Pierre-Boucher, Longueuil, in young adult males with no evidence of immunosuppression and negative serological testing for antibody against the human immunodeficiency virus. Clinical presentation consisted of odynophagia, fever and retrosternal chest pain. All patients rapidly improved with acyclovir therapy.

Snoring, apnea, and nasal resistance.

OBJECTIVE: To understand the impact of the nose in relation to snoring, to increased and decreased nasal resistance and sleep, to nasal anatomy and physiology in snorers and apneic patients, and to nocturnal episodes of respiratory obstruction in relation to nasal obstruction. DESIGN: A select group of patients, in whom nasal reconstruction and uvulopalatopharyngoplasty (UPPP) were combined, were studied. A review of the literature is included. METHODS: A questionnaire was given to all patients. MAIN OUTCOME MEASURES: Patients' snoring improvement was evaluated postoperatively. RESULTS: Overall, 174 of the 180 patients (97%) believed their snoring to be improved postoperatively after combined nasal reconstruction and UPPP were done. CONCLUSION: A review of the literature, a review of snorers' pathophysiology, and the results of this study show that nasal surgery and UPPP combined are effective in improving snoring.

Pleomorphic soft tissue myogenic sarcomas of adulthood. A reappraisal in the mid-1990s.

325 diverse sarcomas, 39 rhabdomyosarcomas (RMS), including all histologic variants, and 135 leiomyosarcomas (LMS) were identified. Within these two groups, 18 (46%) of the RMS and 14 (10%) of the LMS represented pleomorphic variants. These neoplasms were studied by morphology (histology and ultrastructure) and by immunohistochemical methods employing antibodies to intermediate filaments (vimentin and desmin) and actin isoforms [alpha-smooth (sm) and alpha-sarcomeric (sr) actins]. Twenty-four pleomorphic malignant fibrous histiocytomas (MFH) and eight pleomorphic liposarcomas (LS) were examined in a similar fashion. By light microscopy, the pleomorphic RMS, LMS, and MFH were indistinguishable, as each was dominated by pleomorphic cells disposed in a haphazard growth pattern; moreover, many featured fascicular, storiform, and sclerotic zones. The distinction between these neoplasms became apparent only following immunohistochemistry and/or ultrastructural study. All pleomorphic RMS disclosed rudimentary sarcomeres and exhibited the following cytoskeletal profile: vimentin (+) (18 of 18), desmin (+) (14 of 18), alpha-sr actin (+) (18 of 18) and alpha-sm actin (+) (five of 18). All the pleomorphic LMS featured smooth-muscle differentiation of variable degrees in the form of cytoplasmic bundles of microfilaments and associated dense bodies; their cytoskeletal profile was vimentin (+) (14 of 14), desmin (+) (seven of 14), alpha-sr actin (+) (none of 14), and alpha-sm actin (+) (eight of 14). The latter was demonstrated in all moderately differentiated, but absent or only focally expressed in poorly differentiated variants. All pleomorphic MFH and LS were devoid of myogenic (skeletal or smooth) ultrastructural features and expressed vimentin solely. This combined morphological and immunohistochemical study illustrates the following: First, these pleomorphic sarcomas are often indistinguishable by histologic growth pattern alone; thus, an accurate diagnosis requires study with all of these techniques. Second, pleomorphic myogenic sarcomas are restricted to adults and are not uncommon neoplasms among pleomorphic sarcomas: RMS (28%), LMS (21%), MFH (38%), and LS (13%). Third, the study defines desmin-negative and alpha-sm actin-positive pleomorphic RMS, and desmin-negative and alpha-sm-actin-negative pleomorphic LMS.

Potential damaging effects of blue light on the eye.

Are we really well protected from light reflected on the enamel of the teeth during photopolymerisation?

The glycosylated hemoglobin assay for diabetes: its value to the periodontist. Two case reports.

The glycosylated hemoglobin assay is a relatively new test used in the diagnosis and monitoring of the diabetic patient. This assay should be of interest to the periodontist as it offers important advantages over traditional blood glucose testing methods. Most importantly, it gives an indication of the blood glucose level over an extended period of time (30 to 90 days), whereas traditional assays only indicate the glucose level at one point in time. Additionally, there is no requirement for fasting prior to testing. Two case reports are presented to illustrate how the glycosylated hemoglobin assay can be utilized by the periodontist.

Comparison of five-view and three-view cervical spine series in the evaluation of patients with cervical trauma.

The three-view trauma series has been the standard screening examination for patients with cervical spine trauma. We conducted a prospective study to determine if the addition of supine oblique views to the three-view series would improve detection of fractures, subluxations, dislocations, or locked facets. All patients over a two-year period with suspected cervical spine injury had a five-view series obtained (three-view series and supine oblique views), and selected high-risk patients underwent thin-section conventional tomography of the cervical spine. Films were interpreted separately by two radiologists and an emergency physician, and the tomography results were used as the gold standard for comparison. Thirty-three of 58 high-risk patients had one or more fractures, subluxation, or dislocation demonstrated on tomography. There were no fractures or dislocations detected on the five-view series that were not detected or suspected on the three-view series. In areas of the cervical spine reported to be better visualized by supine oblique views than three-view series, our results indicate that supine oblique views did not improve detection but did, in certain cases, allow more specific diagnosis of injuries. Our data do not support the routine use of supine oblique views in the initial radiographic evaluation of patients with cervical spine trauma.

Initial characterization of cells derived from human periodontia.

The studies presented in this report describe an initial characterization of cell types derived from explants of human periodontia. Cell cultures were established from human periodontal ligament (PL4, PL7), gingival tissue (GF2), and alveolar bone (BP1) by means of explant techniques and monolayer culture. Cells were studied at passage numbers 2-4 and were characterized on the basis of morphological, biochemical, and proliferative parameters. Subconfluent cells did not have distinct morphologies useful in distinguishing them from one another. At confluence, PL4 and BP1 cells formed multilayered cultures of randomly oriented cells, while PL7 and GF2 cells grew in a monolayer of parallel cells. Biochemically, PL4 and BP1 cells exhibited characteristics consistent with an osteoblast-like phenotype. These included a significant increase in PTH-stimulated cyclic AMP and high basal levels of alkaline phosphatase activity, which were decreased on exposure to PTH and increased after stimulation by 1.25 dihydroxyvitamin D3. In contrast, PL7 and GF2 cells exhibited basal alkaline phosphatase levels that were low, and cyclic AMP levels were not modulated by PTH stimulation. Cell populations PL7 and GF2 did not proliferate in culture medium supplemented with 3% platelet-poor plasma. After the addition of platelet-derived growth factor (PDGF) to this medium, the proliferation of these cell populations was equal to that in media supplemented with 10% fetal bovine serum. In contrast, PL4 and BP1 cells did proliferate in culture medium supplemented with 3% platelet-poor plasma. The addition of PDGF to the medium resulted in only a moderate increase in the proliferation of cell populations PL4 and BP1.(ABSTRACT TRUNCATED AT 250 WORDS)

[Snoring: physiopathology, surgical treatment and a modified uvulo-palato-pharyngoplasty]. / Le ronflement: physiopathologie traitement chirurgical et technique modifee d'uvulo-palato-pharyngoplastie.

Sleep apnea, now recognized as a specific clinicopathological entity, had received little attention until late 1960 when described by Gastaud. Since that time, following the works of Ikematsu, Guillemineault and Fujita, there has been rapid extension in the knowledge and understanding of sleep problems and associated surgery. Snoring, whether part of the sleep apnea syndrome or alone, may be explained with the help of an aerodynamic model comparing the pharynx to a Starling resistance. The factors nasal obstruction, abnormal mass in the upper respiratory airways and transmural resistance are discussed in the light of this model. To modify some of the above factors, surgical techniques have been described. We feel these conventional techniques do not take into account the normal healing process of inverted double C scars. We have modified the classic technique by sectioning the palatopharyngeus muscle and used Z-plasty to close the surgical defect. This is followed by a limited resection of the soft palate. As a consequence, the soft palate is being brought forward in the healing process and the oropharynx AP diameter is enlarged. This minimal type of resection of the soft palate precludes complications of velopharyngeal incompetency or relative pharyngeal stenosis. We have studied 200 snorers and operated on 90 of them, 25 according to the standard technique and 65 with the modified technique. The modified technique, while limiting the amount of palate to be removed and also the morbidity, is easy to standardize and offers as good results with fewer risks.

The potential role of platelet-derived growth factor as an autocrine or paracrine factor for human bone cells.

Platelet-derived growth factor, PDGF, is a potent mitogen for cells of mesenchymal origin such as fibroblasts, smooth muscle cells and glial cells. PDGF is thought to have the potential to act as both a paracrine and an autocrine factor. Studies described here extend these observations to human bone-derived cells. Exogenous PDGF induces biologic activity in two human osteogenic sarcoma cell lines and in one of these, the two PDGF genes, PDGF-1 and PDGF-2/c-sis are expressed. In addition, PDGF stimulates proliferation of normal osteoblastic cells derived from adult human cancellous bone. The expression of the PDGF-1 gene but not the PDGF-2/c-sis gene is demonstrated in normal human adult bone-derived cells by Northern blot analysis and synthesis of PDGF is shown by immunoprecipitation with PDGF antisera. These studies indicate that PDGF has the potential to act as a paracrine or autocrine regulator of bone cells.

Study of the growth factor requirements of human bone-derived cells: a comparison with human fibroblasts.

Recent techniques have been devised for the culture of bone cells derived from human bone explants. These cells, which are thought to represent several stages in the osteoblast lineage, respond to PTH with an increase in cyclic AMP content, and have high basal alkaline phosphatase activity which is increased on exposure to 1,25-dihydroxyvitamin D3 and decreased by PTH. Such characteristics distinguish these cells from fibroblasts. In this study, we demonstrate that human bone-derived cells also differ from fibroblasts in their growth characteristics. Bone-derived cells proliferated in basal medium supplemented with platelet-poor plasma. The rate of proliferation was enhanced by additional supplementation with platelet-derived growth factor (PDGF), and further increased when a combination of growth factors was added (PDGF, TGF-beta and EGF). In contrast, fibroblasts did not proliferate in basal medium supplemented with platelet-poor plasma and the addition of PDGF alone stimulated fibroblast proliferation to the same extent as 10% fetal bovine serum. Supplementation with other growth factors did not further enhance the response of fibroblasts to PDGF. These results emphasize the differences in proliferative responses between human bone-derived cells and human fibroblasts, and indicate that the factors responsible for osseous regeneration in vivo may differ from those factors which regulate repair of soft tissue wounds.

Health problems of data entry clerks and related job stressors.

A study was made of health problems reported by data entry clerks working in two large data pools within the Québec Public Service Administration. In order to collect the data, 350 clerks answered a questionnaire, representing a return rate of 92%. The results indicate that, in comparison with women in other occupations, the data entry clerks have a high rate of occurrence of psychiatric symptoms (measured by the Ilfeld index) as well as a high degree of use of over-the-counter and prescription drugs. In addition, these two problems are more prevalent in full-time clerks than in part-time clerks. The psychiatric symptoms appear related to the combined influence of two main factors: work overload and the monotony of work specialization. A third factor, the quality of the relationships among workers in the pool, also seemed to affect the regular full-time clerks.

[The organization of work and the mental health of nurses aides.]. / Organisation du travail et santé mentale chez les auxiliaires en saisie des données.

The aim of this article is to focus on the problems encountered by auxiliaries collecting data within the frame work of a certain organization of work. A questionnaire was distributed to two big groups in the public sector. It was answered by three hundred and fifty auxiliaries with a 92% rate of response. In comparison with other jobs occupied by women, these auxiliaries present a much higher incidence of depressive or anxious symptoms and of drug abuse. The recourse to a regressive model helps to explain the results by the combined effect of two factors amongst others: first, by a strong pressure to perform and then by the monotony of piecework. It is possible that the alienation symbol of the last two decades is not the worker at the assembly line but, with the preponderance of computerised office, is now the woman reducing to the collection of date.

Isolation and characterization of cytochrome b5 from Candida tropicalis grown on alkane.

Cytochrome b5 from Candida tropicalis grown on alkane has been solubulized in three different ways (sodium cholate, trypsin, osmotic wash). After solubilization of the microsomal membrane with sodium cholate, the purification of cytochrome b5 was achieved by DEAE-cellulose chromatography, hydroxylapatite chromatography, a second DEAE-cellulose chromatography and a Sephadex G-75 gel filtration. The purified protein had an apparent molecular weight of 16 000 +/- 1 000. After solubilization by trypsin treatment or osmotic wash, the purification procedure yielded a protein with an apparent molecular weight of 12 000 +/- 1 000. Though the purified proteins presented molecular weights depending on the technique of solubilization, they exhibited identical optical properties, a great stability with respect to temperature and pH, and were all autooxidable. Redox titrations revealed differences in their midpoint potential values, which were 35 +/- 5 mV for the b5 purified after cholate solubilization, -59 +/- 5 mV for the b5 purified after trypsin treatment and -65 +/- 5 mV for the b5 purified after osmotic wash.