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Biomedical subjects

A Rosen

Publications and source records attributed to A Rosen.

At least 19 recordsLinked to original sources
PubMed1992

MARCKS is an actin filament crosslinking protein regulated by protein kinase C and calcium-calmodulin.

AGONISTS that stimulate protein kinase C (PKC) induce profound changes in cell morphology correlating with the reorganization of submembranous actin, but no direct connection between PKC and actin assembly has been identified. The myristoylated, alanine-rich C kinase substrate (MARCKS) binds calmodulin and is a predominant, specific substrate of PKC which is phosphorylated during macrophage and neutrophil activation , growth factor-dependent mitogenesis and neurosecretion; it is redistributed from plasma membrane to cytoplasm when phosphorylated and is involved in leukocyte motility. Here we report that MARCKS is a filamentous (F) actin crosslinking protein, with activity that is inhibited by PKC-mediated phosphorylation and by binding to calcium-calmodulin. MARCKS may be a regulated crossbridge between actin and the plasma membrane, and modulation of the actin crosslinking activity of the MARCKS protein by calmodulin and phosphorylation represents a potential convergence of the calcium-calmodulin and PKC signal transduction pathways in the regulation of the actin cytoskeleton.

Actin Cytoskeleton↗
PubMed1992

Treatment of lymphangioleiomyomatosis by ovariectomy, interferon alpha 2b and tamoxifen--a case report.

The gender-specific prevalence of lymphangioleiomyomatosis (LAM) in premenopausal women suggests a hormonal etiology. Despite the antiestrogenic treatment (ovariectomy, tamoxifen) this disease is often refractory to therapy and almost inevitably leads to the patient's death. We describe a case where the antiproliferative effect of systemically applied interferon alpha 2b was successfully employed in addition to ovariectomy and the patient reached complete remission.

Adult↗
PubMed1992

Microwave thermal balloon angioplasty in the normal rabbit.

The feasibility of utilizing microwave energy for thermal angioplasty was evaluated in 28 normal New Zealand white rabbits. Angioplasty catheters were inserted via bilateral femoral arteriotomy and balloon angioplasty was performed on the external iliac arteries. There were three variables in the microwave angioplasty procedure: peak temperature, energy duration, and peak balloon pressure. At 1 week after the angioplasty, animals were put to death and the iliac arteries were removed after perfusion fixation. Histologic analysis was performed. Injuries to the medial and intimal proliferation were evaluated using an index based on the circumferential extent and depth of abnormality. There was no relationship noted between intimal proliferation or medial injury and energy duration of peak balloon pressure. There was a direct relationship between peak temperature and medial injury. Furthermore, there was an inverse relationship between medial injury and intimal proliferation. The axial extent of change induced by microwave energy was 1.6 cm. Microwave thermal energy delivery through a balloon angioplasty catheter is feasible and can be performed conveniently.

Angioplasty, Balloon↗
PubMed1992

[Obstetrical management of dysfibrinogenemia with increased thrombophilia].

Dysfibrinogenaemias are characterised by qualitatively abnormal fibrinogen, causing functional defects. In pregnant women, the incidence of recurrent abortions and placental abruption as well as haemostatic complications is high. In this case report, we report on a 22 year old woman with dysfibrinogenaemia complicated by thrombotic episodes. After two stillbirths under dramatic circumstances (placental abruption, eclampsia) and after an early abortion (7th gestational week), the patient was treated by subcutaneously administered heparin. Pregnancy ended successfully by delivery in the 39th gestational week.

Adult↗
PubMed1992

[Mastopathy in partial testicular feminization].

We report on a patient with synchrony of mastopathic alterations and incomplete testicular feminization. In the 54-year old patient, typical climacteric complaints as well as mastopathy-associated symptoms occurred. After orchiectomy and subsequent oestrogen substitution, clinical symptoms disappeared.

Androgen-Insensitivity Syndrome↗
PubMed1992

Blood-containing aerosols generated by surgical techniques: a possible infectious hazard.

The aerosols generated in an operating room during surgery were simulated in the laboratory by using a variety of common surgical power tools. A Stryker bone saw, a Hall drill, and a Shea drill were used on bone, and a Bovie electrocautery was used in both the cutting and coagulation modes on tendon, all in the presence of a thin film of blood. A 10-stage, low-pressure cascade impactor was used to determine the particle size distribution of each aerosol, and Hemastix was used to assess the hemoglobin content of each particle size fraction. The same assessment was done for another series of blood aerosols that had previously shown the ability to infect human T-cell cultures. All of the tools tested produced blood-containing aerosol particles in the respirable size range (less than 5 microns). Because surgical masks offer little protection against such particles, personal sampling is indicated to define the risk of exposure to bloodborne pathogens by this route.

Aerosols↗
PubMed1992

Influence of valve surgery on female fertility.

Pregnancies following cardiac valve surgery represent a considerable maternal and fetal risk. The present paper is a report of 163 women in child-bearing age who underwent cardiac valve surgery. Congenital (14.7%) and acquired (85.3%) cardiac defects required a total of 72 alloplastic and 16 bioprosthetic valve implantations. In 69 patients, purely instrumental correction was performed, in 6 patients conduits were placed. Thirty-four pregnancies were observed and led to the delivery of 18 healthy infants. The birth weight was always in the 2-sigma normal range or slightly above. Three cesarean sections were performed due to the cardiac defect, in 6 patients vacuum extraction or forceps delivery was done, and in 9 patients delivery was spontaneous. We observed 4 cases of spontaneous abortion, and in 12 cases interruption of pregnancy. 75.1% women never became pregnant. Potential risks in terms of endocarditis, repeated valve implantation and anticoagulation are emphasized, methods to decrease the physical strain during delivery are discussed.

Bioprosthesis↗
PubMed1992

Workplace compliance with a no-smoking law: a randomized community intervention trial.

BACKGROUND: Compliance with state and local laws restricting smoking in public places and workplaces has not been systematically evaluated. METHODS: We assessed workplace compliance with a comprehensive no-smoking law adopted in Brookline, Mass, and tested whether mailing information to businesses increased awareness of and compliance with the law. We conducted a random sample telephone survey of 299 businesses (87% response rate). Self-reported compliance was validated by direct observations. RESULTS: One year after its adoption, the law was popular with businesses. The prevalence of smoking restrictions, smoking policies, and no-smoking signs was 80%, 59%, and 40%, respectively. One third of businesses banned smoking. Full compliance with the law was low, however, because few businesses posted a copy of their smoking policy as required. The mailing increased employers' awareness of the law. Employers sent the mailing also reported better compliance, but this was not confirmed by direct observations. CONCLUSIONS: The law was popular and contributed to a high prevalence of workplace smoking restrictions. Different interpretations of the law by policymakers and businesses seemed to explain why formal compliance was low. The mailing increased awareness of, but not compliance with, the law.

Administrative Personnel↗
PubMed1992

Smoking reduction during pregnancy by a program of self-help and clinical support.

This study investigated the impact of a low-cost, pregnancy-specific self-help smoking-cessation program on patient smoking behavior both pre- and postpartum. The population consisted of 274 English-speaking women enrolled in a large health maintenance organization who reported smoking at the time of the baseline survey or had quit within the previous 3 months. A control group receiving standard obstetric care was compared with two experimental groups, one receiving the self-help materials and standard care and the other receiving the materials plus brief regular clinician interactions and counseling about smoking. Smoking data were obtained from two additional self-reported surveys conducted at 6 months' gestation and approximately 8 weeks postpartum. Self-reported smoking behavior was verified using a urine cotinine test, which revealed no significant differences between the groups. Among baseline smokers, although neither intervention yielded significantly higher 6-month nonsmoking rates compared with controls, both interventions significantly increased the proportion of women who were not smoking postpartum. Among those who had quit smoking at baseline, only the more intensive intervention significantly increased maintenance of non-smoking postpartum. Brief counseling, a simple charting system, and improved access to educational materials allowed the program to be integrated easily into routine prenatal care at a cost of $50-111 per patient.

Adolescent↗
PubMed1992

Cell type and differentiation dependent heterogeneity in retinoblastoma protein expression in SCID mouse fetuses.

The expression pattern of retinoblastoma (Rb) protein has been studied at the single cell level in frozen sections of 16- to 18-day-old SCID mouse fetuses by immunofluorescence staining with mouse monoclonal and rabbit polyclonal antibodies, using conventional epifluorescence and confocal laser scanning microscopy. The nuclei of megakaryocytes, hemopoietic islands of the fetal liver, osteo-, amelo-, and odontoblasts, and skeletal muscle were strongly stained. There was no detectable Rb staining in the basal cell layers of stratified squamous epithelia, but the differentiating, more superficial layers were positive. Intestinal crypts were negative, whereas the villi were positive. In the retina, Rb protein was detectable in the inner ganglion layer but not in the outer neuroblastic layer. In the central nervous system, Rb protein was present in neurons and glia cells as well. The nuclei in the collecting tubules of the kidney, the pancreas, and the adrenal cortex were Rb positive. Analysis of the differentiation dependent expression of Rb protein in relation to the prospective life cycle of the cells in which it appears may pave the way toward an understanding of the tissue specific oncogenic effect of Rb loss in families with hereditary retinoblastoma.

Animals↗
PubMed1991

Regulation by phosphorylation of reversible association of a myristoylated protein kinase C substrate with the plasma membrane.

Protein kinase C (PKC) transduces receptor-mediated signals by phosphorylating membrane-bound substrates which then act as effectors of specific cellular responses. The myristoylated alanine-rich C kinase substrate (MARCKS) is a specific PKC substrate which has been implicated in macrophage activation, neuro-secretion and growth factor-dependent mitogenesis. Myristoylation of MARCKS is required for effective binding to the plasma membrane where it colocalizes with PKC. Here we report that PKC-dependent phosphorylation displaces MARCKS from the membrane and that its subsequent dephosphorylation is accompanied by its reassociation with the membrane. This cycle of phosphorylation-dependent membrane attachment and detachment of a myristoylated protein represents a novel mechanism of reversible membrane targeting. As MARCKS is a calmodulin- and actin-binding protein (ref. 8, and J. Hartwig et al., manuscript submitted), the cycle of membrane attachment/detachment represents a mechanism through which PKC might reversibly regulate actin-membrane interaction.

Adenosine Triphosphate↗
PubMed1991

[Hydrops fetalis caused by maternal Parvovirus B19 infection].

Maternal infection with human Parvovirus B19 during pregnancy is one of the rare reasons, which can lead to a not immunologically conditioned hydrops fetalis. We report here a case of intrauterine Parvovirus infection associated with hydrops fetalis, diagnosed by intrauterine sonography in the 29 week of gestation, one week after the outbreak of Erythema. The B19 infection of the low birth weight baby, delivered in the 30 week of gestation, was diagnosed serologically with specific IgM and IgG against B19 by ELISA. No malformation could be detected in the liveborn infant, who died on the third day of life.

Antibodies, Viral↗
PubMed1991

Is CA-125 monitoring useful in patients with epithelial ovarian carcinoma and preoperative negative CA-125 serum levels?

Between December 1983 and December 1988 we examined the postoperative tumor marker development and correlated this to the clinical course of the disease in 56 patients suffering from primary epithelial ovarian carcinoma of International Federation of Gynecology and Obstetrics stages I-III and with a preoperative CA-125 serum level less than or equal to 65 U/ml. In 54% of all cases there was a reduction of more than 50% of the CA-125 serum level within the first 3 months after surgery. Nine out of thirteen patients with progressive disease (69%) showed an increasing CA-125 serum level with a median lead time of 6 months (0-11 months) prior to clinical diagnosis. These preliminary results indicate that the monitoring of cancer patients with CA-125 tumor marker seems to be a useful method of early diagnosis of progressive disease even in patients with preoperative serum levels lower than 65 U/ml.

Antigens, Tumor-Associated, Carbohydrate↗