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1.  Converting a teaching hospital medical clinic to a group practice: patients vote with their feet. 
Public Health Reports  1986;101(1):76-82.
Traditional general medical clinics (GMCs) have been criticized as providing less than optimal primary care while losing money for the sponsoring teaching hospital. In addition, the GMC has become less attractive as a site for training house staff. In response, a number of teaching hospitals have sponsored the development of a primary care group practice as a more efficient alternative to the GMC. Under the new model, certain measures of patient care frequently improve, house staff receive better training, and the hospital may be able to trim financial losses. While the literature contains numerous descriptions of such conversions, very little information is available about the compliance of patients who are transferred to the new model with relatively little preparation or choice. Institutions that convert their GMCs may do so to attract new clientele. But they have a responsibility to their long-time patients and certainly should address the question of whom they expect to transfer successfully and what the dropout rate will be. New York City's Mount Sinai Hospital completed conversion of its GMC to a primary care group practice in 1983. A sampling of patients taken before the conversion, then followed up 6 months latter, revealed that 82 percent of the former GMC patients were successfully referred to the new model. Patients given specific appointments rather than instructions to call for their own appointment had a better "show" rate. Noncompliers were more likely to be female, Medicaid-covered, 46-65 years old, and living outside the hospital's immediate service area.(ABSTRACT TRUNCATED AT 250 WORDS)
PMCID: PMC1477654  PMID: 3080795
2.  Expression of the c-myc proto-oncogene during development of Xenopus laevis. 
Molecular and Cellular Biology  1986;6(12):4499-4508.
We isolated and characterized Xenopus laevis c-myc cDNAs from an oocyte-specific library. These cDNA clones encompass 2.35 kilobases of the X. laevis c-myc RNA and contain the entire coding domain of 1,257 nucleotides of the 419-amino acid-long X. laevis c-myc protein. The 2.7-kilobase X. laevis c-myc mRNA is expressed in the oocyte, maintained in the egg, and is present throughout the early cleavage stages of embryogenesis. At the time of transcriptional activation in the embryo the c-myc RNA levels show a significant decline and then reaccumulate continuously throughout the remainder of premorphogenic development. At the early neurula stage of embryogenesis the pattern of c-myc RNA expression is elevated in the mesoderm with respect to the endoderm and ectoderm. In the adult X. laevis the c-myc mRNA is expressed in some (e.g., skin, muscle) but not all differentiated tissues. The X. laevis c-myc protein migrates as a doublet of 61,000- and 64,000-dalton species. Both species are phosphorylated in oocytes and somatic cells, exhibit extremely short half-lives of less than 30 min, and are localized to the nuclear fraction of somatic cells. By contrast, the oocyte protein shows both cytoplasmic and germinal vesicle distribution and appears to be stable.
PMCID: PMC367234  PMID: 3540613
3.  Influence of reduced concentration of L-glutamine on growth and viability of cells in monolayer, in spheroids, and in experimental tumours. 
British Journal of Cancer  1986;54(5):733-741.
L-Glutamine is a requirement for many cells in tissue culture, an intermediate in many metabolic pathways, and an alternative substrate to glucose for energy metabolism. These properties suggest that glutamine concentration might be a determinant of cell viability in tumours, especially in regions that are deficient in other metabolites. We have therefore studied the effects of glutamine depletion on single cells in culture, on spheroids and on experimental tumours. Absence of glutamine suppressed the growth rate of two cell lines, but cells cultured for up to 6 h in the absence of glutamine had no decrease in plating efficiency. There was little effect on growth of MGH-U1 (human bladder cancer) spheroids of varying the glutamine concentration in the range of 0.1 to 2 mM and spheroids exposed to these concentrations did not develop central necrosis. Lower concentration of glutamine suppressed the rate of spheroid growth, and spheroids did not grow in the absence of glutamine. Pseudomonas 7A glutaminase reduced the survival of cells in glutamine-free culture and prevented growth of spheroids. Glutaminase was injected into mice bearing experimental tumours to reduce blood levels of glutamine; some animals also received 15 Gy radiation to their tumours to assess the effects of glutamine levels on surviving nutrient-deprived (i.e. hypoxic) cells. Glutaminase had no effect on cell survival in the Lewis lung tumour or in MGH-U1 xenografts, with or without radiation; glutaminase caused dose-dependent growth delay of the KHT tumour, which was additive to that caused by radiation. The present results suggest that (i) short-term changes of glutamine concentration have small effects on cell viability; and (ii) depletion of glutamine levels in blood through the in vivo use of glutaminase is unlikely to produce major therapeutic effects against nutrient-deprived cells in solid tumours.
PMCID: PMC2001537  PMID: 3801270
4.  Effect of verapamil and sodium cromoglycate on leukotriene D4 induced bronchoconstriction in patients with asthma. 
Thorax  1986;41(10):753-758.
Leukotriene D4 (LTD4) may be an important mediator in asthma. The effect of verapamil and sodium cromoglycate on LTD4 induced bronchoconstriction has been examined in seven patients with asthma. The bronchoconstrictor response to increasing concentrations of inhaled LTD4 (0.0032-50 micrograms/ml) was assessed by measuring changes in FEV1, specific airways conductance, and flow rate at 30% of vital capacity (V30(p)). Results were expressed as the provocation concentration (PC) producing a 10% fall in FEV1 (PC10FEV1), a 35% fall in specific airways conductance (PC35SGaw), and a 30% fall in flow at 30% of vital capacity (PC30 V30(p)). Neither verapamil nor cromoglycate inhibited LTD4 induced bronchoconstriction in asthmatic subjects. These results suggest that in asthmatic patients LTD4 induced bronchoconstriction is not mediated via verapamil or cromoglycate sensitive mechanisms.
PMCID: PMC460470  PMID: 3097863
7.  Epidemic of AIDS related virus (HTLV-III/LAV) infection among intravenous drug abusers. 
Stored blood samples from 164 intravenous drug abusers who attended a Scottish general practice were tested for HTLV-III/LAV (human T cell lymphotropic virus type III/lymphadenopathy associated virus) infection. Of those tested, 83 (51%) were seropositive, which is well above the prevalence reported elsewhere in Britain and Europe and approaches that observed in New York City. The timing of taking samples of negative sera and continued drug use suggest that as many as 85% of this population might now be infected. The infection became epidemic in late 1983 and early 1984, thereafter becoming endemic. The practice of sharing needles and syringes correlated with seropositivity, which, combined with the almost exclusive intravenous use of heroin and other behavioural patterns, may explain the high prevalence of HTLV-III/LAV infection in the area. Rapid and aggressive intervention is needed to control the spread of infection.
PMCID: PMC1339512  PMID: 3081158
8.  In vitro and in vivo effect of verapamil on human airway responsiveness to leukotriene D4. 
Thorax  1986;41(1):12-16.
The mechanism by which leukotriene D4 (LTD4) induces airway narrowing in man is unclear. We have investigated this by examining the effect of the calcium channel blocker verapamil on the sensitivity of in vitro preparations of human bronchi to LTD4 and methacholine, and on the bronchoconstriction induced in normal subjects by these agonists in vivo. In vitro smooth muscle sensitivity was assessed by the concentration of LTD4 and methacholine causing a 50% of maximum contraction (EC50) and as the maximum tension generated. Verapamil did not alter baseline tension or the response to LTD4 but did inhibit contractile responses to methacholine. In vivo studies were performed in six normal subjects; they inhaled increasing concentrations of LTD4 (0.4-50 micrograms/ml) or methacholine (2-64 mg/ml). Airway responsiveness in vivo was expressed as the provocation concentration (PC) of agonist producing a 35% fall in specific airways conductance (PC35sGaw) and a 30% fall in flow at 30% of vital capacity (PC30 V30(p)). Verapamil did not alter baseline sGaw or V30(p). One subject did not respond to LTD4 on either day. In contrast to the in vitro results, verapamil produced a greater than 10 fold reduction in LTD4 induced bronchoconstriction, but had no effect on methacholine induced bronchoconstriction. These results suggest that in normal subjects bronchoconstriction induced by inhaled LTD4 is due to a combination of direct and indirect mechanisms.
PMCID: PMC460245  PMID: 3518128

Results 1-8 (8)