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Biomedical subjects

M Baron

Publications and source records attributed to M Baron.

285 records · Page 16Linked to original sources
PubMedDate not supplied

Genetic linkage between X-chromosome markers and bipolar affective illness.

A pedigree study shows close linkage of bipolar affective illness (manic depression) to the X-chromosome markers colour blindness and glucose-6-phosphate dehydrogenase deficiency. The maximum lod score ranges from 7.52 (assuming homogeneity) to 9.17 (assuming heterogeneity); that is, the odds in favour of linkage range between 3 X 10(7) to 1 and 10(9) to 1. These results provide confirmation that a major psychiatric disorder can be caused by a single genetic defect. As a possible first step in characterizing the primary genetic abnormality, this finding may have important implications for the aetiology, nosology, pathophysiology and, possibly, prevention and treatment of bipolar affective disorder. It also provides a means for identifying and characterizing homogeneous populations of patients and may help in clarifying aetiological heterogeneity.

Bipolar Disorder↗
PubMedDate not supplied

The solution structure of human epidermal growth factor.

The epidermal growth factors (EGFs) are powerful mitogens for a wide variety of cells in culture; human EGF (hEGF), known as urogastrone, also inhibits gastric acid secretion in vivo. The transforming growth factors (TGF-alpha) are related to the EGF family both in sequence and activity and EGF-like sequences are often observed in a wide range of functionally unrelated proteins. Attempts to examine the structure of EGF by diffraction methods have not yet succeeded because of difficulties with crystallization. We report here a three-dimensional structure of a biologically active derivative (residues 1-48) of the 53-residue human EGF. An analysis of high resolution 1H nuclear magnetic resonance (NMR) spectra was used together with a combination of distance geometry, restrained energy minimization and restrained molecular dynamics methods. The three-dimensional structure provides a basis for understanding the properties of EGFs and for predicting the structures of homologous sequences in other proteins.

Chemical Phenomena↗
PubMedDate not supplied

Multiple levels of Notch signal regulation (review).

Notch is a vitally important signalling receptor controlling cell fate determination and pattern formation in numerous ways during development of both invertebrate and vertebrate species. An intriguing pathway for the Notch signal has emerged where, after ligand-dependent proteolysis, an intracellular fragment of the receptor itself translocates to the nucleus to regulate gene expression. The nuclear activity of the Notch intracellular domain is linked to complexes regulating chromatin organization through histone deacetylation and acetylation. To allow the Notch signal to be deployed in numerous contexts, many different mechanisms have evolved to regulate the level, duration and spatial distribution of Notch activity. Regulation occurs at multiple levels including patterns of ligand and receptor expression, Notch-ligand interactions, trafficking of the receptor and ligands, and covalent modifications including glycosylation, phosphorylation and ubiquitination. Several Notch regulatory proteins have conserved domains that link them to the ubiquitination pathway, and ubiquitination of the Notch intracellular domain has recently been linked to its degradation. Different proteolytically derived isoforms of Notch have also been identified that may be involved in alternative Notch-dependent signals or regulatory mechanisms, and differences between the four mammalian Notch homologues are beginning to be appreciated.

Animals↗
PubMedDate not supplied

Changes in attitudes toward cesarean birth.

OBJECTIVE: To compare the findings of three studies of women's responses to planned and unplanned cesarean birth. DESIGN: Descriptive. SETTING: Private obstetric practices, childbirth education classes, and hospital postpartum units. PARTICIPANTS: Study 1: 24 women who had cesarean deliveries between 1973 and 1980; Study 2: 15 women who delivered in 1981-82; Study 3: 173 women who delivered in 1989-90. MAIN OUTCOME MEASURE: Qualitative data were obtained by an investigator-developed open-ended questionnaire that was mailed to participants after cesarean delivery. RESULTS: The findings from the three studies indicate that the dominant responses to cesarean birth are happiness and excitement about the newborn, accompanied by disappointment about having to have a cesarean delivery. The women in Study 1 expressed the highest proportion of ineffective responses and the lowest proportion of adaptive responses (p = .003), whereas the women in Studies 2 and 3 expressed approximately equal percentages of adaptive and ineffective responses. Women who had unplanned cesarean deliveries had a lower percentage of adaptive responses and a higher percentage of ineffective responses than those who had planned cesarean deliveries (p < .05). Women who had regional anesthesia had more adaptive responses than those who had general anesthesia (p = .0217). CONCLUSION: The findings suggest that women who deliver by cesarean section require continued attention and sensitive care that takes into account their special needs for information, for the presence of their partners throughout the birth experience, and for sustained contact with their newborn.

Adaptation, Psychological↗
PubMedDate not supplied

Lethal photosensitization, autogenous bone, and e-PTFE membrane for the treatment of peri-implantitis: preliminary results.

This clinical study reports on the results of a new method in the treatment of peri-implantitis. The surfaces of 24 plasma flame-sprayed cylindric implants in 17 patients who were diagnosed with peri-implantitis were decontaminated with a combination of toluidine blue (100 micrograms/mL) and laser irradiation at a wavelength of 906 nm. Bone defects were filled with autogenous bone using e-PTFE membranes for retention of the grafting material. Premature membrane exposure occurred in all patients after an average of 3 weeks (+/- 10 days), which required immediate removal of the exposed membrane in 1 patient. Since the soft tissue showed minimal signs of inflammation, the membranes were left in situ for another 6 weeks in all other patients. The mean radiographic peri-implant bone gain was 2 mm +/- 1.90 mm after 9.5 months (maxilla 2.5 mm +/- 2.38 mm; mandible 1.9 mm +/- 1.87 mm). Two implants around which the initial bone defect had already reached the basket had to be removed after 10 months and 35 months, respectively, despite radiographic evidence of improvement of the peri-implant defect. The longer the membrane stayed in situ, the more bone was gained, as long as the membrane was covered by soft tissue (P = .01). However, the longer an exposed membrane was left in place, the smaller the resultant bone gain (P = .0001). Therefore, despite the absence of clinical signs of inflammation, exposed membranes should be removed immediately. The short-term results of this study corroborate the efficacy of the applied treatment method in prolonging the service time of dental implants involved with peri-implantitis.

Alveolar Bone Loss↗
PubMedDate not supplied

Experimentally induced peri-implantitis: a review of different treatment methods described in the literature.

The aim of this article was to present the experimental peri-implantitis models described in the literature and to provide a review of currently used treatment methods. For this purpose, 29 English- and German-language studies published in internationally reviewed journals were examined for similarities and differences regarding animal models, types of implants, and methods used for inducing peri-implantitis. In almost all studies, the implants were located in the mandible, which suggests that peri-implantitis of the maxilla has been researched very little. While in most studies, peri-implantitis was induced by means of ligature and plaque accumulation, only 3 studies have been published that attempted to induce peri-implantitis by means of mechanical overload. Of the latter, only one author observed peri-implant bone resorption. Eleven studies reporting on ligature-induced peri-implantitis presented enough data to be subjected to further statistical data analyses. Meta-analysis revealed that the period of ligature application, and thus the duration of plaque accumulation, generally had no influence on the resultant depth of the bone defect. However, when screw-type and cylindric implants were analyzed separately, a weakly significant positive effect of the duration of ligature application on the resultant defect depth was determined for cylindric implants (P = .092). This could imply that smooth screw-type implants were less susceptible to ligature-induced peri-implant inflammation. Regenerative treatment methods included the membrane technique using non-resorbable membranes (guided bone regeneration), augmentation with autogenous bone, augmentation with bone substitute materials (hydroxyapatite or demineralized freeze-dried bone) or with recombinant human bone morphogenetic protein-2, and a combination of membrane and augmentation procedures. While all described methods resulted in acceptable bone gain, it seems to be difficult to achieve new osseointegration (reosseointegration) of treated implants. Of all tested treatment methods, the combination of guided bone regeneration and augmentation with demineralized freeze-dried bone resulted in the most favorable results regarding bone gain and reosseointegration.

Animals↗
PubMedDate not supplied

X-linkage and manic-depressive illness: a reassessment.

Genetic-epidemiological data and linkage studies with chromosomal markers are reviewed from the vantage point of X-linked inheritance. The results overall suggest that a gene predisposing to manic depression (bipolar affective illness) localized on the X-chromosome may exist in a subgroup of bipolar cases. However, in light of conflicting findings and methodological uncertainties in studying a disorder with unclear phenotype and complex inheritance, this issue is not yet closed. Additional research, including new linkage data and extension and re-evaluation of published data, is required to further our understanding of this intriguing hypothesis.

Bipolar Disorder↗
PubMedDate not supplied

[Acquired phimosis, or preputial sclero-atrophic lichen in children].

From 1979 to 1988, 8 cases of balanitis xerotica obliterans were histologically demonstrated in children at Nantes University Hospital. In 6 of these 8 patients, whose average age at the time of consultation was 9.4 years, the phimosis was obviously acquired or recurrent, and the prepuce was sclerous, thick, and produced a tight distal phimosis. One child coming to consultation for relapsing urinary infections at once presented with a long, tight stenosis of the anterior ureter, associated with a dilatation of the upstream ureter and a filiform stream of urine. All the children were circumcised, and the histological study of the specimen demonstrated characteristic lesions in the superficial derma. During the same operation, meatostomy was performed in two children presenting with meatal stenosis. Six of 8 children were followed up with an average time lapse of 6 months: one of them presented with an involvement of the glans penis and a moderate meatal stenosis, which disappeared spontaneously. No improvement occurred for the child presenting with an extensive stenosis of the anterior ureter, in spite of the local instillation of androgens then of corticoids, but his left kidney was dilated on sonograms. Balanitis xerotica obliterans in children is often not recognized and regarded as a common phimosis; it can be suspected because of the clinical features of the phimosis. The condition must be confirmed by the histological study of a circumcision specimen, then followed up regularly to prevent any risk of involvement of the glans, of the ureteral meatus or of the anterior ureter.

Adolescent↗
PubMedDate not supplied

Antigen-specific suppressor cell activity in patients with scleroderma.

Antigen-specific suppressor cell activity (SCA) of peripheral blood mononuclear cells was investigated in 22 patients with scleroderma (PSS) and 22 age and sex matched healthy controls. SCA was induced by priming peripheral blood mononuclear cells with high dose antigen (ovalbumin). Antigen-specific SCA was measured by determining the ability of the primed cells to suppress an optimal ovalbumin specific plaque forming cell (PFC) response in an autologous target culture. The in vitro PFC response and suppressor cell activity of the PSS patients was not different from that of the normal controls. Antigen dose-response curves of the priming phase of the assay were similar in both the patient and control groups.

Adult↗
PubMedDate not supplied

Neuroarthropathy (Charcot joints) in familial amyloid polyneuropathy.

Two patients with familial amyloid polyneuropathy (FAP) of Andrade type developed neuroarthropathy (Charcot joints). In 1 patient both knees were affected and in the other patient both ankles. This complication added markedly to the already severe disability and limitation of movement caused by the underlying illness. To the best of our knowledge this is the first description of Charcot joints in FAP. Neuroarthropathy in FAP is probably more common than previously suspected and should be sought in any case of FAP with joint disease.

Adult↗
PubMedDate not supplied

Hyperviscosity syndrome in rheumatoid arthritis.

The course of a patient with rheumatoid hyperviscosity syndrome is described. Manifestations of hyperviscosity included somnolence, circulatory overload, bleeding diathesis and dilated retinal veins. Serum hyperviscosity was associated with marked hypergammaglobulinemia, elevated IgM and IgG serum concentrations, and high titers of rheumatoid factor. High molecular weight IgG-IgM immune complexes shown in the serum were considered responsible for the increased viscosity. An unusual feature of the hyperviscosity, was spurious hyponatremia and a negative anion gap. Plasmapheresis rapidly controlled acute features of hyperviscosity, lowered gamma globulin concentrations and led to normal serum sodium and anion gap. Clinical improvement was maintained with moderate prednisone doses.

Aged↗
PubMedDate not supplied

The coexistence of rheumatoid arthritis and scleroderma: a case report and review of the literature.

We describe a patient with all the features of the CREST syndrome variant of scleroderma who developed a destructive arthropathy typical of rheumatoid arthritis (RA). A pulmonary rheumatoid nodule was found confirming the presence of RA. The rarity of the coexistence of these two diseases in the same patient suggests that, despite commonly found overlapping features, these illnesses are distinct entities.

Aged↗
PubMedDate not supplied

[The prevention of the recurrence of stage pTa bladder tumors using intravesical instillation of BCG].

45 patients were included in a retrospective study designed to assess the long-term efficacy and tolerance of immunotherapy by intravesical BCG instillation in the treatment of stage pTa bladder tumours (mean follow-up 52.7 months, range: 12-87 months). 41 patients (91% responded to immunotherapy: 24 (53%) did not develop anu recurrences with a mean follow-up of 49.4 months (range: 19-87 months) and 17 (37.7%) were improved by treatment as the interval between recurrences was significantly increased. 4 patients (8.8%) failed to respond to BCG therapy with progression to stage pTa G3 vesical papillomatosis in one patient. The local tolerance was poor for twelve patients (26.6%), requiring discontinuation or spacing of the instillations. Other complications such as prostatitis and intense fever were observed. Three patients had persistent disturbances of micturition following treatment in the form of urinary frequency due to the decreased bladder volume. Neither the grade, nor the frequency of recurrences prior to treatment, nor the solitary or multifocal nature, nor the site of the initial tumour appeared to influence the response to BCG therapy and did not constitute independent individual prognostic indicators.

Administration, Intravesical↗
PubMedDate not supplied

Effects of information on adaptation to cesarean birth.

The effects of cesarean birth information given in childbirth preparation classes on maternal postpartum reactions to unplanned cesarean delivery were examined. An experimental group received comprehensive cesarean birth information as part of standard childbirth preparation classes. The control group received a standard childbirth preparation class curriculum that included limited cesarean birth information. The control group reported a slight decline in pain intensity from 1-2 days to 6 weeks postpartum, whereas the experimental group showed no change over time. No differences between the two groups were found in perception of the birth experience, physical distress, self-esteem, functional status, feelings about the baby, or quality of the marital relationship. The lack of substantial differences between the groups may be due to the normalizing effect of the high cesarean birth rate and greater attention given to this method of childbirth by expectant parents and childbirth educators.

Activities of Daily Living↗