PubMed Health⌕ Search

Biomedical subjects

D I Cohen

Publications and source records attributed to D I Cohen.

At least 55 records · Page 3Linked to original sources

Academic group practice. The patient's perspective.

The effect upon patient satisfaction of a reorganization of a traditional medical clinic into a group practice model was examined in a controlled trial in which both patients and physicians were randomized. The group practice model, unlike the traditional clinic, provided decentralized registration, 5 days/week clinic coverage, and night/weekend phone coverage. Residents worked in small groups with an attending physician, a nurse practitioner, and a receptionist. This reorganization resulted in a substantial decrease in charges and utilization for patients in the experimental group. A panel of 302 patients was interviewed prior to the reorganization and 1 year later. Patients in the experimental groups perceived improvements in access to their physicians as well as decreases in clinic waiting time and decreases in the lag time between requesting and obtaining an appointment. General health perceptions and other satisfaction measures were unchanged. The authors conclude that a group practice organization can result in decreased patient charges without substantially altering patient satisfaction.

Academic Medical Centers↗

Ig RNA expression in normal B cells stimulated with anti-IgM antibody and T cell-derived growth and differentiation factors.

An increase in mRNA encoding the secretory form of the mu heavy (H) chain (mus) and in the ratio of mus mRNA to the mRNA encoding the membrane form of the microH chain (micron) occurs in normal B cells stimulated with anti-IgM and BSF-p1 together with the two B cell differentiation factors B15-TRF and EL-TRF. Stimulation of cells with anti-IgM and BSF-p1 with either B15- or EL-TRF causes no change in mus levels or mus/micron ratios. The requirements for induction of high rate IgM synthesis in normal B cells stimulated with anti-IgM were precisely the same as those required for elevation of mus, mRNA levels and for increase in mus/micron mRNA ratios. A very close correlation also exists between induction of mRNA for J chain and increase in mus mRNA levels. Similarly, the increase in J chain protein concentration and percent of cells with cytoplasmic IgM were correlated to each other and to levels of mus and J chain mRNA. These results indicate that elevation of mus mRNA and mus/micron mRNA ratios occur in normal B cells only upon commitment to IgM synthesis, and reaffirm the close relation between IgM synthesis and the presence of J chain.

Animals↗

Cell-type-specific cDNA probes and the murine I region: the localization and orientation of Ad alpha.

Labeled cDNA probes highly enriched for B-cell-specific (B-T) and T-suppressor-cell-specific (Ts-B) sequences were used to screen a set of genomic cosmid clones spanning 230 kilobases of the murine immune response (I) region. With the B-cell derived probe, four I-region genes were detectable (A beta, E beta, E beta 2, and E alpha), as well as an additional (fifth) region of hybridization. The T-cell probe, prepared from a putative I-J positive suppressor cell hybridoma, was negative in a parallel experiment. A genomic fragment corresponding to the new region of hybridization seen with the B-cell cDNA probe identified a discrete mRNA species in RNA blotting analysis that had a pattern of expression strikingly similar to E alpha mRNA in a variety of lymphoid tumor lines. This fragment was also used to isolate cDNA clones from a library highly enriched (20-40 times) for B-cell-specific sequences (selected cDNA cloning). DNA sequence analysis of one of these cDNA clones indicates that this gene encodes the A alpha molecule of the d haplotype (Ad alpha). These findings establish that the order of the class II genes in the Ia complex is as follows: centromere-A beta-A alpha-E beta-E beta 2-E alpha.

Animals↗

Intravenous therapy team and peripheral venous catheter-associated complications. A prospective controlled study.

A prospective controlled trial was conducted on four similar inpatient medical wards to test the hypothesis that a trained intravenous therapy (IVT) team would substantially reduce the incidence of peripheral intravenous (IV) catheter-related complications. We followed 863 IV catheters. The overall incidence of phlebitis in the ward staff-maintained IV catheters was 32% as compared with 15% for those maintained by the IVT team. The incidence of two more serious complications (cellulitis and suppurative phlebitis) was reduced tenfold from 2.1% to 0.2%. We conclude that an IVT team can substantially reduce the iatrogenic complications related to IV catheters.

Catheterization↗

A Campylobacter enteritis outbreak in a military base in Israel.

An outbreak of gastroenteritis due to Campylobacter jejuni occurred during a 2-day period in June 1982 in a military base in Israel. Of 22 patients with acute gastroenteritis examined at the unit's medical clinic, 17 were available for complete clinical evaluation. Stool cultures were taken from them as well as from 23 asymptomatic soldiers including food handlers. In 6 of the 17 patients with enteritis (35%) Campylobacter jejuni serotype 11 was isolated, while the stool cultures of all the asymptomatic soldiers were negative. A temporary food handler was the most probable source of the infection. He had suffered from symptoms of acute gastroenteritis prior to the outbreak but had not reported them, and was found to harbor the same Campylobacter serotype as the other patients.

Acute Disease↗

The natural history of intravenous catheter-associated phlebitis.

During a controlled evaluation of an intravenous therapy (IVT) team, we had the opportunity to follow up 202 episodes of catheter-associated phlebitis. While the IVT team had a considerable effect on the incidence of phlebitis, the clinical course of this complication was not influenced. More than 40% of catheter-associated phlebitis occurred more than 24 hours after withdrawal of the catheter. Premonitory symptoms were not useful in predicting the development of phlebitis. Factors that influenced the duration of phlebitis included the patient's diagnosis and the administration of vancomycin hydrochloride. The duration of phlebitis was prolonged by delayed removal of the catheter after the development of phlebitis.

Catheterization↗

Improving physician compliance with preventive medicine guidelines.

Similar general medical outpatient clinics with randomly assigned patients were used to evaluate the effectiveness of a program that was to increase house staff compliance with preventive medicine guidelines. Two clinics were designated experimental and two served as controls. In the experimental clinics, age-specific checklists of all recommended preventive procedures (drawn from the Canadian Task Force report on The Periodic Health Examination and American Cancer Society guidelines) were appended to each patient's chart. In addition, house officers were presented with a series of weekly seminars dealing with issues in screening, as well as the specific recommendations included in the checklist. House officers in all four clinics were tested for their knowledge and attitudes toward the preventive program before and after the intervention. Counts of immunizations and mammograms performed and the total populations eligible for these procedures were determined for all four clinics. As predicted, test scores as well as mammography and immunization rates increased significantly (from 2-40 per cent) in the intervention clinics as compared with controls. We conclude that this intervention was clearly effective in the short run. However, follow-up studies will be necessary to determine whether the desired long-term effect has been achieved.

Attitude of Health Personnel↗

Influence of obstetricians' attitudes on their use of prenatal diagnosis for the detection of Down's syndrome.

Practising obstetricians were surveyed to determine the relation between their referral patterns and their knowledge and attitudes concerning prenatal diagnosis by amniocentesis for women aged 35 years and over. Although 82% had referred at least one eligible patient for prenatal diagnosis during the past year, almost none had used the available services for all appropriate patients. There was a statistically significant trend for increased referral as correct knowledge of the risks and accuracy of prenatal diagnosis increased. Moreover, a discriminant function combining risk and accuracy estimates, type and size of practice, and language distinguished the referrers from the nonreferrers (P = 0.0002), although there was considerable overlap between the physicians classified according to a high, moderate or low rate of referral. The data suggest that while knowledge and practice characteristics can distinguish obstetricians who refer patients for prenatal diagnosis from those who never do so, the frequency of referral may involve other factors, such as how physicians accept innovation and perceive risks.

Adult↗

A quick method for the preparation of stable DNP red cell conjugates.

Another procedure for preparing dinitrophenyl (DNP) sheep erythrocytes (SRBC) using the DNP-alanylglycylglycyl hapten has been developed. These DNP-SRBC also are stable for as long as 1 month, but the conjugation procedure is much simpler to carry out than the previously reported method.

Animals↗

The use of prenatal cytogenetic diagnosis: a comparison of rates in prepaid group practices and the general population.

To determine whether the reduction in services associated with prepaid group practice is indiscriminate or limited to medically "discretionary" services, the author compared the utilization rates for prenatal cytogenetic diagnosis (a medically indicated service for women aged 35 and older) in prepaid group practices and the geographically corresponding populations-at-large in four settings. The utilization rates by members of the prepaid group practices were equal to rate calculated for the geographically correspondings populations-at-large in two settings, and 2.3 times greater in the other settings. Whatever factors which may be responsible for the reduction of discretionary services delivered to members of prepaid group practices do not appear to interfere with the delivery of a strongly indicated service, prenatal cytogenetic diagnosis, in the population at risk.

California↗

Altered copper absorption in tumor-bearing and estrogen-treated rats.

Intestinal copper absorption was studied in normal, tumor-bearing and estrogen-treated rats, using 64Cu(NO3)2. Rats bearing Dunning mammary tumors (DMBA 5A) of more than 2 g absorbed 70-100% more of an intragastric copper dose than controls, and a much larger percentage was found in the plasma, with less in liver and kidney. The distribution of copper measured chemically mimicked these findings, and the enhanced capacity for absorption was also demonstrated in vitro with everted duodenal segments. Further examination of the intestinal mucosa revealed that binding of radioactive copper to a 10,000-dalton component of the cytosol was inversely proportional to the amount absorbed into the body, tumor-bearing rats retaining much less in, and transferring much more from, the intestine than controls. Daily injection of 17 beta-estradiol over 2 wk had the reverse effect. It is concluded that the absorption of copper is an endogenously regulated process that may be altered by cancer and estrogen treatment and mediated by the extent of its binding to a component (possibly metallothionein) within the mucosal cell.

Animals↗

Isolation of cDNA clones encoding T cell-specific membrane-associated proteins.

Of 10 distinct cloned DNA copies of mRNAs expressed in T lymphocytes but not in B lymphocytes and associated with membrane-bound polysomes, one hybridizes to a region of the genome that has rearranged in a T-cell lymphoma and several T-cell hybridomas. These characteristics suggest that it encodes one chain of the elusive antigen receptor on the surface of T lymphocytes.

Animals↗

Sequence relationships between putative T-cell receptor polypeptides and immunoglobulins.

Comparison of the sequence of a cloned T cell-specific cDNA with those of cross-reacting cloned cDNAs isolated from a thymocyte library indicates the presence of variable, constant and joining regions remarkably similar in size and sequence to those encoding immunoglobulin proteins. Together with the evidence for somatic gene rearrangements reported in the accompanying paper, this strongly suggests that the TM86 cDNA clone encodes one chain of the T-cell receptor for antigen.

Amino Acid Sequence↗

A third type of murine T-cell receptor gene.

By subtractive cDNA hybridizations, we have isolated a new species of T-cell receptor cDNA clone whose predicted amino acid sequence has homology to variable, constant, joining and diversity segments of immunoglobulins and T-cell receptors. The corresponding genomic sequence is also rearranged in several T-cell DNAs. The four potential N-linked glycosylation sites, frequency of expression and predicted molecular weight (27,800) of this molecule make it a likely candidate for the alpha-chain of the T-cell receptor. Expression data also indicate that this gene may be activated at a later stage of T-cell differentiation than the beta-chain.

Amino Acid Sequence↗