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Biomedical subjects

M Gordon

Publications and source records attributed to M Gordon.

At least 235 records · Page 13Linked to original sources
PubMed1991

Resident scheduling: night float programs.

Obstetrics and gynecology residency programs have traditionally involved long hours in the hospital. In recent years, in an attempt to determine whether work hours could be reduced while at least maintaining resident education and patient care, many program directors have instituted night float systems. In New York State, these systems must adhere to rigid hospital code requirements (limiting total hours worked and with specific mandates regarding time away from the hospital); in other areas, these requirements are not as limiting. At the request of the Council on Resident Education in Obstetrics and Gynecology, residency program directors and residents in the United States and Canada were sent a survey regarding whether they had a night float program, how it was structured, and what changes it was perceived to have caused. Responses were received from 193 program directors (65%) and 302 residents. Major differences were noted in the structure of the programs within New York state compared with those outside the state. In New York, 63% of the programs had residents in all 4 years participating in the night float; this was true for only 10% of the programs outside New York. In New York state, the programs were required to adhere to state hospital code requirements limiting hours on duty and mandating the specifics of time off, whereas the programs outside New York did not necessarily adhere to these restrictive requirements. Twelve characteristics were evaluated regarding changes that were perceived to have occurred as a result of the night float program.(ABSTRACT TRUNCATED AT 250 WORDS)

Gynecology↗
PubMed1990

A novel surface antigen expressed by mature and activated rabbit T-lymphocytes.

The monoclonal antibody (Mab) 93C6 was used to identify a surface molecule expressed by mature and activated rabbit T-lymphocytes. This antigen was virtually absent in cells of the thymus (5% positive cells). All 93C6-positive cells expressed the rabbit pan-T marker L11-135 and proliferated in response to concanavalin A (Con A). When lymphocytes were activated in the presence of Con A, the expression of the 93C6 molecule was quantitatively increased. Con A stimulation alone did not markedly enhance expression of this antigen by thymocytes, but stimulation with both Con A and interleukin-2 (IL-2) resulted in a population of thymocytes that expressed the antigen in a manner quantitatively similar to that of mature T-cells in other tissues.

Animals↗
PubMed1990

Differential control of tropomyosin mRNA levels during myogenesis suggests the existence of an isoform competition-autoregulatory compensation control mechanism.

We have isolated tropomyosin cDNAs from human skeletal muscle and nonmuscle cDNA libraries and constructed gene-specific DNA probes for each of the four functional tropomyosin genes. These DNA probes were used to define the regulation of the corresponding mRNAs during the process of myogenesis. Tropomyosin regulation was compared with that of beta- and gamma-actin. No two striated muscle-specific tropomyosin mRNAs are coordinately accumulated during myogenesis nor in adult striated muscles. Similarly, no two nonmuscle tropomyosins are coordinately repressed during myogenesis. However, mRNAs encoding the 248 amino acid nonmuscle tropomyosins and beta- and gamma-actin are more persistent in adult skeletal muscle than those encoding the 284 amino acid nonmuscle tropomyosins. In particular, the nonmuscle tropomyosin Tm4 is expressed at similar levels in adult rat nonmuscle and striated muscle tissues. We conclude that each tropomyosin mRNA has its own unique determinants of accumulation and that the 248 amino acid nonmuscle tropomyosins may have a role in the architecture of the adult myofiber. The variable regulation of nonmuscle isoforms during myogenesis suggests that the different isoforms compete for inclusion into cellular structures and that compensating autoregulation of mRNA levels bring gene expression into alignment with the competitiveness of each individual gene product. Such an isoform competition-autoregulatory compensation mechanism would readily explain the unique regulation of each gene.

Animals↗
PubMed1990

Analysis of the hotfoot (ho) locus by creation of an insertional mutation in a transgenic mouse.

Hotfoot (ho) mutation is a recessive trait in mice, characterized by motor disorder and male sterility, that maps to chromosome 6. We have identified a transgenic mouse pedigree with a similar trait. Using genetic and molecular approaches, we have demonstrated that the foreign DNA element is located in or near the ho locus. This new allele, designated hoJwg and presumably created by insertional mutagenesis, should make it possible to clone the ho gene. Male infertility in hoJwg male homozygotes was determined to be due to inability of sperm to penetrate the zona pellucida. This was demonstrated by rescuing mutant males by a new technique of gamete micromanipulation, zona pellucida drilling. These findings show that zona drilling is useful both for analysis and preservation of animals with reduced male fertility.

Animals↗
PubMed1990

Hemiparkinsonism-hemiatrophy syndrome: clinical and neuroradiologic features.

We evaluated 11 patients with hemiparkinson-hemiatrophy syndrome, 6 with body and contralateral cerebral hemispheric hemiatrophy, 4 with only body hemiatrophy, and 1 with just brain hemiatrophy. The mean age of symptom onset was 38.1 years (range, 18 to 54) with 5.2 +/- 3.1 (mean +/- SD) years of illness until the last follow-up visit. The presenting symptom was unilateral tremor in 6 patients, hand dystonia in 2, bradykinesia in 2, and abnormal gait in 1 patient. Three patients had a good response to levodopa, 4 had moderate response, and 2 patients had a poor response. During a mean follow-up period of 1.7 years (range, 4 months to 5 years), the Hoehn and Yahr score changed in only 3 patients: 2 gained 1.5 points and 1 gained 3 points over 2.5 years. We discuss the association between hemiparkinsonism-body hemiatrophy and contralateral hemispheric hemiatrophy, and raise the possibility of early childhood brain insult with delayed-onset parkinsonism.

Adolescent↗
PubMed1990

Continuous fetal heart rate monitoring and tocodynamometry in routine obstetrical care, fetal stress and non-stress testing, and labor induction in the chimpanzee (Pan troglodytes).

The use of continuous fetal heart rate (FHR) and uterine pressure monitoring in the chimpanzee (Pan troglodytes) by external Doppler transducer and tocodynamometer is described in 1) the routine obstetrical assessment of fetal well-being, 2) oxytocin challenge (stress) testing (OCT) and non-stress testing (NST) for the diagnosis of in utero fetal distress, and 3) induction of labor by intravenous oxytocin infusion, by surgical rupture of the chorio-amniotic membranes (amniotomy), or by a combination of these techniques, as an alternative to Caesarean section for clinical, managemental, or experimental purposes. FHR traces were analyzed during a total of 57 term pregnancies for three basic characteristics: baseline rate, variability, and periodic pattern. Results indicated that continuous FHR monitoring in the chimpanzee can provide a valuable tool for fetal assessment and management of labor in any attempt to reduce the unacceptably high annual incidence of perinatal and neonatal infant mortality reported in the U.S.

Amnion↗
PubMed1990

The plateau in cytotoxic cancer drug discovery.

An examination of the history of cytotoxic cancer drugs development suggests that this activity is now on a plateau. It is striking that there have been no new chemotype cytotoxic anticancer drugs discovered in the past twenty years, despite the massive national effort in this area. It has been estimated that only 40 to 50% of patients currently diagnosed as having cancer will have a five year survival of the disease. This survival rate has been climbing at less than five percent per decade. Our conclusion is that a greater effort in biological response modification is warranted if we are to significantly affect the plateau.

Animals↗