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Biomedical subjects

M Stark

Publications and source records attributed to M Stark.

At least 37 records · Page 2Linked to original sources
PubMed2000

A community-level HIV prevention intervention for inner-city women: results of the women and infants demonstration projects.

OBJECTIVES: This study examined the effects of a multisite community-level HIV prevention intervention on women's condom-use behaviors. METHODS: The theory-based behavioral intervention was implemented with low-income, primarily African American women in 4 urban communities. It was evaluated with data from pre- and postintervention cross-sectional surveys in matched intervention and comparison communities. RESULTS: At baseline, 68% of the women had no intention of using condoms with their main partners and 70% were not using condoms consistently with other partners. After 2 years of intervention activities, increases in rates of talking with main partners about condoms were significantly larger in intervention communities than in comparison communities (P = .03). Intervention communities also had significant increases in the proportion of women who had tried to get their main partners to use condoms (P = .01). The trends for condom use with other partners were similar but nonsignificant. CONCLUSIONS: Many women at risk for HIV infection are still not using condoms. Community-level interventions may be an effective way to reach large numbers of women and change their condom-use behaviors, particularly their behaviors with regard to communication with main sex partners.

Adult↗
PubMed1999

A three-dimensional model of the mouse at embryonic day 9.

This paper describes a digital, three-dimensional model of the mouse embryo at E9. The model was made by reconstruction from images of serial histological sections digitally warped to remove distortions and has a resolution of approximately 9 microns. The model can be digitally resectioned in any plane to provide images which resemble conventional histological sections. The main tissues have been identified and delineated by digital painting so that the anatomical components can be visualized and manipulated in 3-D surface- and volume-rendered views. This provides a three-dimensional definition of anatomy that will provide a useful tool for interpreting and understanding spatial data in mouse embryos. The anatomy of the model is discussed where it provides landmarks for interpretation and navigation or where it is unexpected in light of existing descriptions of the E9 mouse embryo. The complete anatomy is not presented in this paper but will be available on CD-ROM. A detailed description of the technical aspects of the construction of the model is included in an appendix. The model is the first of a series that will form the basis for an atlas/database of mouse development. This reconstruction and its associated anatomy are available in a variety of data formats with some supporting software from http:@genex.hgu.mrc.ac.uk/.

Anatomy, Cross-Sectional↗
PubMed1999

[Operative laparoscopy in pregnancy].

The development of laparoscopic surgery in gynecology and general surgery has greatly advanced over the past decade, and recently has been successfully performed in pregnancy. In the English literature we found that of the 518 cases reported (mean age 32 years) the most common was for cholecystectomy (45%), followed by operations on the adnexae (34%), appendectomy (15%) and others (6%). To these we add 3 cases of cholecystectomy and 1 of an adnexal tumor. Of all the reported cases, 33% were performed in the 1st trimester, 56% in the 2nd and 11% in the 3rd. This review demonstrates a definite trend to laparoscopy in pregnancy. It appears to be safe when performed by experienced surgeons, but further studies addressing safety of laparoscopic surgery during pregnancy are needed to reach definitive conclusions.

Adult↗
PubMed1999

Pregnancy and laparoscopic surgery.

We reviewed the English literature regarding laparoscopic surgery during pregnancy and found that of 518 reported procedures, the most common was cholecystectomy (45%), followed by adnexal surgery (34%), appendectomy (15%), and other operations (6%). We add six cases to this list; three cholecystectomies, an adnexal procedure, and two for abdominal pain. Thirty-three percent were performed in the first trimester, 56% in the second, and 11% in the third trimester. This review demonstrates a definite trend, indicating that laparoscopy in pregnancy appears to be safe when performed by experienced practitioners. (J Am Assoc Gynecol Laparosc 6(3):347-351, 1999)

Abdominal Pain↗
PubMed1999

Immunocytochemically detected free peritoneal tumour cells (FPTC) are a strong prognostic factor in gastric carcinoma.

We prospectively investigated the prognostic significance of free peritoneal tumour cells (FPTC) in a series of 118 patients with completely resected gastric carcinoma. Immunocytochemistry with the monoclonal antibody Ber-Ep4 was performed on cytospins from intraoperative peritoneal lavage specimens. Twenty-three patients (20%) had FPTC which was significantly correlated with pT and pN categories, stage, tumour size, lymphatic invasion, Laurèn and WHO classifications and perigastric adipose tissue metastases. The median survival time for all FPTC positive compared with negative patients was significantly shorter (11 compared with >72 months), with estimated 5-year survival rates of 8% vs. 60%. None of the patients with FPTC had an early gastric cancer. In advanced tumour subgroups without and with serosal invasion (n = 59 and 35), there were 19% and 34% with FPTC. Multivariate survival analysis showed nodal status, FPTC, mesenteric lymphangiosis, and lymph node metastasis to the compartment III to be independent prognostic factors with relative risks of 6.6, 4.5, 2.9 and 2.2 respectively. Recurrent disease occurred in 91% of FPTC-positive and in 38% of FPTC-negative patients. FPTC had a positive predictive value of 91% and a specificity of 97% for tumour recurrence. FPTC is a strong negative, independent prognostic indicator for survival in gastric carcinoma.

Adipose Tissue↗
PubMed1999

Isolation and characterization of hydrophobic polypeptides in human bile.

Polypeptides were isolated from human bile by extraction with chloroform/methanol, followed by reversed-phase chromatography in methanol/ethylene chloride and gel filtration in chloroform/methanol. Peptides were characterized by SDS/PAGE, sequence analysis and matrix-assisted laser desorption ionization/time-of-flight mass spectrometry. This identified haemoglobin alpha chain, ATP synthase lipid-binding protein subunit 9, an N-terminal fragment of mac25/insulin-like growth factor-binding protein 7 and an internal fragment of monocyte differentiation antigen CD14, all not described previously in bile. In addition, alpha1-antitrypsin, known in bile from previous work, was also identified. The hydrophobic character of haemoglobin alpha chain is not apparent from its amino acid sequence, but the other polypeptides all have major hydrophobic segments. These results show that several proteins are removed upon organic solvent extraction used for delipidation during the preparation of samples for proteome analysis. Several of the polypeptides found are unexpectedly present in bile, suggesting that specific excretion mechanisms may be involved.

Amino Acid Sequence↗
PubMed1999

EVI2B, a gene lying in an intron of the neurofibromatosis type 1 (NF1) gene, is as the NF1 gene involved in differentiation of melanocytes and keratinocytes and is overexpressed in cells derived from NF1 neurofibromas.

The EVI2B gene is one of three genes embedded in intron 27b of the neurofibromatosis type 1 (NF1; M. Recklinghausen) gene, which are transcribed in the direction opposite that of the NF1 gene. The function of EVI2B and its relation to NF1 symptoms is unknown. Here, the amounts of NF1 and EVI2B mRNA were investigated in detail in cells involved in NF1 manifestations as café-au-lait macules and neurofibromas. These investigations showed that aside from the NF1 gene, EVI2B is involved in melanocyte and keratinocyte differentiation. Whereas in NF1 melanocytes from café-au-lait macules, EVI2B expression was not altered, in fibroblast-like cells derived from neurofibromas, an increased level of EVI2B mRNA was found. We investigated whether this increase was attributable to an influence of NF1 gene expression on the expression of the EVI2B gene, as suggested by the fact that the EVI2B primary transcript is antisense to the NF1 primary transcript. Investigations of cells derived from patients with different amounts of NF1 pre-mRNA showed no correlation between the amount of NF1 pre-mRNA and the increased level of EVI2B mRNA.

Adolescent↗
PubMed1999

Genetic heterogeneity in familial nonmedullary thyroid carcinoma: exclusion of linkage to RET, MNG1, and TCO in 56 families. NMTC Consortium.

Epidemiological studies show a very high relative risk for first degree relatives of probands with thyroid cancer. The familial form of nonmedullary thyroid carcinoma (NMTC) gives a more severe phenotype and appears earlier than its sporadic counterpart. Moreover, benign thyroid pathologies are often observed in NMTC kindreds. Little is known about the genetic risk factors of the disease. To study them, an international consortium has been organized at the International Agency for Research on Cancer over the past 2 yr to collect biological samples from NMTC families. The only genes known to be directly involved in susceptibility to NMTC are MNG1 on chromosome 14q32 and TCO on chromosome 19q13.2, previously localized by us and others. In addition to those two genes, the genes for Cowden's syndrome and familial adenomatous polyposis are associated with thyroid cancer, but not as an indicative phenotype. Another important gene in thyroid carcinogenesis is RET, which is mutated in the majority of cases of hereditary medullary thyroid cancer and rearranged in an important fraction of sporadic cases of NMTC. Here we report the result of a linkage analysis performed on the 56 more informative kindreds we have collected through the international consortium. Linkage analysis using both parametric and nonparametric methods excluded MNG1, TCO, and RET as major genes of susceptibility to NMTC and demonstrated that this trait is characterized by genetic heterogeneity.

Adult↗
PubMed1999

At least three genes account for familial papillary thyroid carcinoma: TCO and MNG1 excluded as susceptibility loci from a large Tasmanian family.

Recent studies have mapped two susceptibility loci which appear to account for familial multinodular goitre (MNG1) and a variant of familial papillary thyroid cancer (PTC), with associated multinodular goitre (TCO). A Tasmanian family (Tas1) has been identified with an autosomal dominant form of PTC. This study has examined the MNG1 and TCO loci to determine if they are similarly predisposing the Tas1 family to PTC. Linkage analysis using identical microsatellite markers described in the two previous studies was used to determine the significance of these loci in the Tasmanian family. The resultant LOD scores were sufficiently negative using multipoint parametric analysis to exclude these two loci from involvement in the Tasmanian family. In addition, six candidate genes, RET, TRK, MET, TSHR, APC and PTEN were also excluded as susceptibility genes in Tas1 by using microsatellites that are positioned in or in close proximity to these genes. These results suggest that there are at least three susceptibility genes that predispose families to familial PTC.

Carcinoma, Papillary↗
PubMed1999

The Misgav Ladach method for cesarean section: method description.

SUBJECT: A method description is given for the Misgav Ladach method for cesarean section. This is based on the Joel-Cohen incision originally introduced for hysterectomy. METHOD: The incision is a straight transverse incision somewhat higher than the Pfannenstiel incision. The subcutaneous tissue is left undisturbed apart from the midline. The rectus sheath is separated along its fibres. The rectus muscles are separated by pulling. The peritoneum is opened by stretching with index fingers. The uterus is opened with an index finger and the hole enlarged between the index finger of one hand and the thumb on the other. The uterus is closed with a one-layer continuous locking stitch. The visceral and parietal peritoneal layers are left open. The rectus muscle is not stitched. The rectus sheath is stitched with a continuous non-locking stitch. The skin is closed with two or three mattress sutures. The space in between is apposed with non-traumatic forceps for 5 minutes. RESULTS: The basic philosophy is to work in harmony with the body's anatomy and physiology and not against them. The method is restrictive in the use of sharp instruments, preferring manual manipulation. CONCLUSION: The method gives quicker recovery, less use of post-operative antibiotics, antifebrile medicines and analgesics. There is a shorter anesthetic and shorter working time for the operative team. It is suitable for both emergency and planned operations.

Cesarean Section↗
PubMed1998

Determination of proteins, phosphatidylethanolamine, and phosphatidylserine in organic solvent extracts of tissue material by analysis of phenylthiocarbamyl derivatives.

Amino acid analysis of organic solvent extracts of tissue material has been evaluated for determination of protein content. Conventional ninhydrin-based analysis does not allow determination of a large number of lipid-rich samples. Therefore, the hydrolyzed samples were treated with phenylisothiocyanate and the phenylthiocarbamyl (PTC) derivatives obtained were separated by reverse-phase HPLC. With this method, analysis of many lipid-rich samples is feasible. In addition, phosphatidylethanolamine and phosphatidylserine can then be determined together with the amino acid constituents. The PTC/reverse-phase HPLC method was used for analysis of chloroform/methanol extracts of spinal cord, lung, and bile after chromatography on Lipidex 5000 in methanol/ethylene chloride, 4:1 (v/v). The chromatography profiles show that in all tissue samples the proteins elute before the phospholipids. Consequently, a single step of Lipidex 5000 chromatography can be used to purify polypeptides present in organic solvent extracts. Using pulmonary surfactant extracts (with about 98% phospholipids and 1-2% proteins), we find that individual contents of surfactant proteins B and C can be determined by amino acid analysis.

Amino Acids↗
PubMed1998

Prenatal sonographic appearance of congenital fibrosarcoma.

Congenital fibrosarcoma is a rare soft tissue sarcoma. A 22-year-old woman in the 22nd week of her first pregnancy underwent sonographic examination, which revealed a soft tissue swelling of the fetus's left thigh. The pregnancy was terminated, and congenital fibrosarcoma was diagnosed by pathologic examination. To our knowledge, this is the first published report of the intrauterine sonographic observation of this tumor in a fetal extremity.

Adult↗
PubMed1998

Phosphatidate phosphatase--a key enzyme in glycerolipid biosynthesis. Studies on the yeast enzyme.

Phosphatidate phosphatase is an important enzyme in glycerolipid biosynthesis, but difficult to purify. A purified preparation of N-ethylmaleimide-sensitive phosphatidate phosphatase from the yeast Saccharomyces cerevisiae was obtained by a five-step protocol, using chromatography on DE-53/DEAE FF, Affi-Gel Blue, hydroxyapatite, Mono-Q, and Superdex 200. A protease-deficient yeast strain gave preparations similar to those of the wild-type strain. In exclusion chromatography, the enzyme activity of all preparations eluted at approximately the same position as albumin. However, the behavior on SDS/PAGE differed considerably among preparations, suggesting a multimeric subunit structure or degradation during purification. A 35-kDa and a 40-kDa protein band which coincided with activity were found in all preparations. Glycerol in the buffers could be excluded without rapid loss of enzyme activity, and Tris could be substituted for ammonium bicarbonate, while at least 0.6% sodium cholate in the buffers was essential.

Electrophoresis, Polyacrylamide Gel↗
PubMed1998

Strong prognostic impact of tumor-associated urokinase-type plasminogen activator in completely resected adenocarcinoma of the esophagus.

The serine protease system has been shown to play an important role in the invasive potential of a variety of tumors. To date, however, there are little data about the expression of these proteases in esophageal carcinoma. To determine the level of expression and the significance of urokinase-type plasminogen activator (uPA) and its plasminogen activator inhibitor type 1 (PAI-1) in adenocarcinoma of the esophagus, we studied 54 tumor cases and a control group of normal gastric mucosa cases with ELISA using detergent-extracted samples. uPA and PAI-1 were significantly elevated as compared to control tissue by factors of 16 and 14, respectively. Median levels of both uPA and PAI-1 showed significant correlation with tumor pT, pN, and pM categories, whereas the presence of lymphatic invasion correlated only with the uPA content and tumor grade correlated only with PAI-1 content. Using maximally selected statistics, a cutoff value was found for uPA (2.85 ng/mg protein) but not for PAI-1, which divided the study group into significantly poorer and better survival subgroups. By univariate analysis, depth of tumor invasion (pT), lymph node involvement (pN), number of involved lymph nodes, lymph node ratio, distant nodal metastases [pM1(Iym)], lymphatic invasion, and uPA showed significant correlations with patient survival. By multivariate analysis, uPA (first rank), pN, and pM (lym) were identified as independent prognostic factors, with relative risks of 8.4, 4.1, and 4.3, respectively. In a second survival analysis method, a prognostic model was developed using classification and regression trees analysis, in which a significant difference among three patient survival groups was distinguished using the variables "number of involved lymph nodes" and "uPA content." In summary, tumor uPA content as determined by ELISA appears to be a powerful, independent prognostic factor for survival in adenocarcinoma of the esophagus.

Adenocarcinoma↗
PubMed1998

Dose-effect relationship of idebenone in an experimental cerebral deficit model. Pilot study in healthy young volunteers with piracetam as reference drug.

Within a general cerebral deficit model--inspiratory hypoxia-the dose--effect relationship of idebenone (CAS 58186-27-9), an antioxidant, was studied with regard to selected electrophysiological and psychometric parameters. Seventeen healthy male volunteers (mean age = 32 years, mean BW = 75 kg) received three different oral medications: placebo, idebenone and piracetam (CAS 7491-74-9) as reference. The test drug idebenone was administered in five different dosages, ranging--in 60 mg steps--from 60 to 300 mg t.id. Piracetam was given at a dose level of 800 mg t.i.d. A strict dose-regimen was used in idebenone for safety reasons. Each dosage/medication--except idebenone 300 mg t.i.d.--was given for one week without washouts in between. On each 7th treatment day, pharmacodynamic assessments comprising electroretinography (ERG), auditory evoked potentials (AEP) and visual analogue scales (VAS) were run. Immediately after the phases with the lower dosages, the study was continued with the highest dosage of idebenone (300 mg t.i.d.) for a period of four weeks with pharmacodynamic assessments on the 7th, 14th and 28th day. In this pilot study, the target variable, the amplitude of the ERG b-wave indicated a definite antihypoxidotic effect after the highest dosage of idebenone. With 300 mg idebenone t.i.d., ERG b-wave amplitudes increased linearily with increasing duration of treatment. The 'central' AEP P2-amplitude demonstrated a different dose-effect relationship. AEP P2-amplitudes increased with increasing dosages of idebenone. The prolongation of treatment with 300 mg t.i.d. resulted in no further improvement of this parameter (ceiling effect). Subjective ratings (VAS) by the volunteers confirmed the results seen in electrophysiological variables. The findings, however, remain to be confirmed within an adequate double-blind, crossover study design.

Adult↗