Biomedical subjects
Publications and source records attributed to D Rogers.
A patient classification system is essential for staffing, budgeting and patient scheduling. This process involves selecting a system, selecting a style, testing, and retesting. This article describes the development and implementation of such a system.
Spondyloepiphyseal dysplasias (SED) are a heterogeneous group of inherited disorders characterized by disproportionate short stature and pleiotropic involvement of the skeletal and ocular systems. Evidence has suggested that SED may result from structural defects in type II collagen. To confirm the validity of this hypothesis, the structure of the "candidate" type II collagen gene (COL2A1) has been directly examined in a relatively large SED family. Coarse scanning of the gene by Southern blot hybridization identified an abnormal restriction pattern in one of the affected members of the kindred. Analysis of selected genomic fragments, amplified by the polymerase chain reaction, precisely localized the molecular defect and demonstrated that all affected family members carried the same heterozygous single-exon deletion. As a consequence of the mutation, nearly 90 percent of the assembled type II collagen homotrimers are expected to contain one or more procollagen subunits harboring an interstitial deletion of 36 amino acids in the triple helical domain.
A radioimmunoassay for cyclo(His-Pro) (CHP) in unextracted human plasma that can detect 40 pg has been developed. Elution profile of CHP-like immunoreactivity (CHP-LI) corresponded precisely to those of [3H] cyclo(His-Pro) by both high pressure liquid chromatography and Sephadex G-25 column chromatography. In addition plasma CHP-LI exhibited close immunoidentity with authentic CHP. Charcoal treatment of plasma containing [3H] cyclo(His-Pro) resulted in loss of both CHP-LI and [3H] cyclo(His-Pro) activity. Plasma frozen at draw and assayed at 0, 6 and 24 hours displayed no change in CHP-LI while an aliquot from the same sample maintained at 4 degrees C and assayed at the same time intervals showed a 50% rise (0 hrs-856 +/- 47 pg/ml; 24 hrs-1288 +/- 85 pg/ml) (+/- SE) over 24 hours. In addition, plasma drawn from 14 volunteers and immediately frozen until assay yielded a mean CHP value of 829 +/- 64 pg/ml (+/- SE) while that of 14 volunteers that was maintained at 25 degrees C for 90 minutes was significantly higher at 1085 +/- 34 pg/ml (+/- SE) (p less than 0.03). Taken together, these data suggest that CHP can be easily measured in a direct RIA of human plasma, however, failure to maintain the sample frozen from the time of draw until assay may yield spuriously elevated values.
The authors explored the role of Cyclo [His-Pro] (CHP) in 50 adolescents who fulfilled DSM III diagnostic criteria for anorexia nervosa and bulimia. CHP, a relatively new neuro modulator which has a role in inducing satiety, was assayed in serum during routine blood work. CHP levels correlated significantly with weight in restrictor (AN-R) (R = -0.449, P less than 0.05) and bulimic anorexics (AN-B) (R = +0.489, P less than 0.01). There was no significant correlation in normal-weight bulimics (NWB) (R = +0.556, P less than 0.01). It did not correlate with weight in a depressed control group. Longitudinal data on six patients showed a similar relationship between weight, purging and CHP binge/purge activity and/or weight changes of around 2 kilograms correlated with average CHP changes of 42%. Clinical material suggests changes in satiety during CHP changes consistent with a satiety disturbance model of these disorders.
Recent evidence indicates that thyroid hormones can regulate thyrotropin secretion in vivo in part by inhibiting thyrotropin-releasing hormone (TRH) secretion itself. Therefore, to explore whether triiodothyronine (T3) interacts with the specific hypothalamic area involved in thyrotropin (TSH) secretory regulation, the paraventricular nucleus (PVN), Palkovitz micropunches from eight nuclear regions were obtained from 1,000-microns frozen coronal brain slices for immunoassay determinations of TRH. Rats were treated either with parenteral L-T3 for 6 days to induce experimental thyrotoxicosis, or 0.15 M saline. The induction of thyrotoxicosis was confirmed by demonstrating that mean plasma TSH concentrations fell from 108 to less than 10 microU/ml (p less than 0.01). TRH concentrations in the PVN were reduced concomitantly after L-T3 from 1.9 to 1.1 ng/mg protein (p less than 0.05). No reductions in TRH concentrations during T3 treatment occurred in other nuclear groupings except in the posterior hypothalamic nucleus. Total TRH content in the median eminence declined also in T3-treated animals from 1.77 to 1.29 ng, representing a 32% reduction (p less than 0.01). No significant change was seen in the median eminence content of the TRH structurally related dipeptide, cyclo(His-Pro). The data herein indicate that experimental thyrotoxicosis in the rat is associated with a selective reduction in TRH concentrations in the PVN, documenting T3 effects upon hypothalamic TRH metabolism per se.
Despite significant growth in the market for private long-term care insurance in recent years, empirical research is lacking on how policy attributes affect consumer preference. Using conjoint techniques, the authors estimate the utility values associated with different levels of long-term care policy attributes, as well as the overall importance of the attributes. A simulation procedure for estimating the percentage of consumers who would prefer specific types of policies also is presented.
The effect of aging on the hemodynamic and sympathetic response to tracheal intubation was evaluated in 27 patients aged 18 to 80 years, ASA Class I and II, given atropine 0.4 mg and diazepam 10 mg as premedication and thiopental, 4.0 mg/kg, and succinylcholine 100 mg for anesthesia induction. Laryngoscopy and tracheal intubation was performed 60 seconds after induction. The elderly had significantly less chronotropic response to intubation 2, 3, 4, and 5 minutes after induction so that the maximum increase in heart rate above awake values was negatively correlated with age (R = -0.66, P less than 0.001). Baseline systolic blood pressure (SBP) and mean BP increased significantly with age (R = 0.81, P less than 0.001 and R = 0.76, P less than 0.001, respectively) but age was not significantly related to increases in SBP and mean BP following intubation. Baseline plasma norepinephrine (NE) levels increased with age ( R = 0.51, P less than 0.01). Following intubation, mean plasma NE concentrations were significantly higher in elderly patients than young patients, despite the diminished heart rate response. Heart rate (HR) per pg/ml of NE, a measure of cardiac sensitivity to beta stimulation, was therefore significantly less 2, 3, and 4 mins after induction in elderly patients than in younger patients. To determine if this alteration in cardiac sensitivity to endogenous catecholamines was reflected by changes in beta receptor function on lymphocytes, beta receptor density and the proportion of receptor binding agonist with high affinity (%RH) were measured. No significant correlation between beta-receptor affinity for agonist, %RH, or receptor density was found with age, HR, or HR per pg/ml NE.(ABSTRACT TRUNCATED AT 250 WORDS)
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The effectiveness of transcutaneous electrical stimulation at acupuncture points for increasing uterine contractions in 20 post-dates pregnant women was assessed in a controlled study. Subjects were randomly assigned to either a treatment condition, consisting of the application via surface electrodes of a 30-Hz current to the points "spleen 6" (lower leg) and "liver 3" (foot), or a placebo condition, in which the equipment was attached but not activated. The frequency and strength of uterine contractions were monitored for 1 hour prior to stimulation and then for the final 2 hours of a 4-hour test period. A significant increase in frequency and strength of uterine contractions was found in the electrically stimulated women compared with the placebo-group women. The possible physiologic mechanisms underlying this effect, and its implication for labor induction, are discussed.
Murine embryonic stem (ES) cells are pluripotent cell lines established directly from the early embryo which can contribute differentiated progeny to all adult tissues, including the germ-cell lineage, after re-incorporation into the normal embryo. They provide both a cellular vector for the generation of transgenic animals and a useful system for the identification of polypeptide factors controlling differentiation processes in early development. In particular, medium conditioned by Buffalo rat liver cells contains a polypeptide factor, ES cell differentiation inhibitory activity (DIA), which specifically suppresses the spontaneous differentiation of ES cells in vitro, thereby permitting their growth as homogeneous stem cell populations in the absence of heterologous feeder cells. ES cell pluripotentiality, including the ability to give rise to functional gametes, is preserved after prolonged culture in Buffalo rat liver media as a source of DIA. Here, we report that purified DIA is related in structure and function to the recently identified hematopoietic regulatory factors human interleukin for DA cells and leukaemia inhibitory factor. DIA and human interleukin DA/leukaemia inhibitory factor have thus been identified as related multifunctional regulatory factors with distinct biological activities in both early embryonic and hematopoietic stem cell systems.
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Previous studies from our laboratory demonstrated that the acute release of PRL from human decidual tissue is stimulated by a 23.5 kilodalton placental protein which we designated decidual PRL-releasing factor (PRL-RF). To determine whether PRL-RF may also affect the synthesis of PRL and/or cause a secondary increase in PRL release, we have examined the effects of purified PRL-RF on the synthesis and release of PRL over a 96-h period. Exposure of dispersed decidual cells to PRL-RF (0.5 microgram/ml) stimulated a biphasic increase in PRL release with acute transient stimulation during the first 0.5 h and a delayed and sustained stimulation beginning about 8 h after exposure which persisted for the duration of the 96 h. The amounts of PRL released from PRL-RF-exposed cells after 0.5, 8, 12, 24, and 96 h were 321.2 +/- 36.2 (mean +/- SEM, n = 3), 110.2 +/- 5.3, 138.2 +/- 7.2, 194.5 +/- 11.2, and 201.5 +/- 14.2% that of control cells. Studies of the de novo synthesis of [35S]methionyl PRL indicated that the increase in PRL release after the first few hours of exposure to PRL-RF was secondary to an increase in PRL synthesis. Somatostatin (100 nM) inhibited the acute stimulatory effect of PRL-RF, but had no effect on the delayed stimulation of PRL release. On the other hand, cycloheximide (20 microM) completely inhibited the secondary increase in PRL release in response to PRL-RF but had no effect on the acute release. These results demonstrate that PRL-RF stimulates both the synthesis and release of decidual PRL.
The present study develops and tests a causal model of home health care utilization by the Lucas County elderly. Path analysis was employed to evaluate the model on an area probability sample of 400 Ohio elderly. The findings indicate that the predictors of home health care are more diverse than was expected with the need factor (need for care, use of health appliances, limits to daily activities), enabling factor (knowledge of resources) and predisposing (age) factors all contributing to the use process.
Effects of rapid normalization of plasma glucose levels (by insulin infused via Alzet pumps implanted intraperitoneally) on plasma insulin-like growth factor I (IGF-I) levels, granulation tissue polyol levels, and vascular permeation by 125I-labeled albumin were examined in male Sprague-Dawley rats with streptozocin-induced (60-65 mg/kg) diabetes. Two days after implantation of pumps, plasma insulin levels were twice normal levels and remained elevated (1.4-2.5 times normal) throughout the remainder of the study. Plasma glucose levels and granulation tissue polyol levels were normalized within 2 days after initiation of insulin treatment. Plasma IGF-I levels were significantly increased (2 times) by 2 days, but were not normalized until 7 days. In contrast, 125I-albumin permeation normalized at a much slower relatively linear rate and was still not completely normal after 14 days of insulin treatment. In view of 1) previous studies demonstrating that diabetes-induced increases in 125I-albumin permeation in this tissue are linked to increased metabolism of glucose to sorbitol and 2) the rapid normalization of tissue polyol levels in this study, the relatively linear rate of normalization of vascular permeability over 14 days in these studies suggests that impaired vascular barrier functional integrity in this model is mediated by structural and/or functional vascular alterations associated with sustained increased polyol metabolism rather than by increased polyol levels per se and/or by readily reversible functional and metabolic alterations associated with acute increases in polyol metabolism.(ABSTRACT TRUNCATED AT 250 WORDS)
In a 3-year period 157 single lumen Broviac catheters were inserted in 145 children with various neoplastic diseases. The overall duration of the catheter courses was 30,533 days (median, 171; range, 2 to 647). Sixty-five percent of the catheter courses (102 of 157) were complicated by at least 1 febrile episode, for a total of 157 episodes. According to European Organization for Research on Treatment of Cancer criteria, 79 febrile episodes (50%) were classified as microbiologically documented infections, 57 (36%) with and 22 (14%) without septicemia; 31 (20%) as clinically documented infections; and 47 (30%) as possible infections. Of the 79 microbiologically documented infections 21 were catheter-related infections (CRI), 32 were catheter-unrelated infections and 26 were infections of unknown source. Only 48% of CRI occurred during neutropenia (less than 1000 neutrophils/mm3), compared with 88% of catheter-unrelated infections and 96% of infections of unknown origin (P = 0.00007). Gram-positive microorganisms (56% staphylococci) accounted for 78% of all isolates in CRI, 47% in catheter-unrelated infections and 43% in infections of unknown origins (P = 0.03). Fungi represented 12% of all isolates. Clinical and microbiologic resolution without removal of the catheter was achieved in 12 of 21 CRI (57%) and no patient died from a CRI. This study indicates that over 3 of 4 of CRI are caused by Gram-positive bacteria, occur in neutropenic and non-neutropenic patients (approximately 50%) and can be successfully treated without removing the catheter.
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After a century of separation, neurology and psychiatry have been drawing closer together over the last 30 years. The two main advances in the understanding of Parkinson's disease over this period have been the discovery of cerebral dopamine deficiency and the appreciation of the large number of its non-motor aspects.