Search PubMed⌕ Search

Biomedical subjects

J A Davis

Publications and source records attributed to J A Davis.

At least 73 records · Page 4Linked to original sources
PubMed1998

Comparison of professional judgment versus an algorithm for nutrition status classification.

OBJECTIVES: The classification of a patient's nutrition status is important for identifying patients who require nutrition care, for designing effective nutrition interventions, and for measuring severity of illness. The objective of this study was to evaluate the reliability and validity of two variants of the Department of Veterans Affairs' nutrition status classification: professional judgment versus an algorithm. METHODS: The study consisted of two phases, both of which included providing a sample of approximately 60 registered dietitians and 60 clinical dietetic technicians with data on 16 (phase I) and 20 (phase II) patients, to which they assigned nutrition statuses using both professional judgment and the algorithm. Improvements in instructions and training were implemented between the two phases. Interrater reliability of the responses was calculated, and content validity was measured by comparing the staff's responses with those of an expert panel. RESULTS: Reliability improved significantly between phases for both professional judgment and the algorithm. Greater reliability and validity were observed with use of the algorithm, by both dietitians and technicians, during both phases. CONCLUSION: Classification of a patient's nutrition status is important in the delivery of cost-effective health care. The Department of Veterans Affairs' nutrition status classification is a good one for assessing nutrition status quickly and reliably, especially when an algorithm is used. The results underscore the advantages of a classification system based on an algorithm when the system is designed to be used by many different staff across multiple facilities.

Adult↗
PubMed1998

Myxoedema madness.

Explore the source record for details and available documents.

Erectile Dysfunction↗
PubMed1998

Implantation of a 16-channel functional electrical stimulation walking system.

A 16-channel electrical stimulation system was implanted in a 39-year-old patient with T10 paraplegia to restore sit to stand, walking, and exercise functions. System implantation required two surgical sessions. In the first session, the posterior muscle set consisting of bilateral semimembranosus, adductor magnus, and gluteus maximus muscles were exposed and epimysial electrodes sutured at the point of greatest muscle contraction. Closed double helix intramuscular electrodes were implanted in the erector spinae. Two weeks later, epimysial electrodes were attached to the eight anterior muscles consisting of the tibialis anterior, sartorius, tensor fasciae latae, and vastus lateralis with all 16 electrode leads passed to the anterior abdominal wall. The electrodes were connected to two eight-channel stimulators placed in the iliac fossae, and the system was checked by activating the individual muscles. The implanted stimulators received stimulation instructions and power via a radio frequency link to an external control. Stimulation patterns for standing, walking, sitting, and exercise functions were chosen from a preprogrammed menu via a finger key pad. After 3 weeks of restricted patient activity, all electrodes stimulated either the target muscle or had an acceptable spillover pattern. The patient is undergoing a 16-week rehabilitation course of stimulated exercises gradually increasing in intensity. At the conclusion, the goal is to discharge the patient with the system for spontaneous use. Although long term followup is required to determine system reliability, preliminary clinical results indicate that targeted, repeatable, functional muscle contractions in the lower extremity can be achieved with a system consisting of epimysial electrodes.

Adult↗
PubMed1997

Cytosolic-free calcium increases to greater than 100 micromolar in ATP-depleted proximal tubules.

Previous studies have shown that cytosolic-free Ca2+ (Caf) increases to at least low micromolar concentrations during ATP depletion of isolated kidney proximal tubules. However, peak levels could not be determined precisely with the Ca2+-sensitive fluorophore, fura-2, because of its high affinity for Ca2+. Now, we have used two low affinity Ca2+ fluorophores, mag-fura-2 (furaptra) and fura-2FF, to quantitate the full magnitude of Caf increase. Between 30 and 60 min after treatment with antimycin to deplete ATP in the presence of glycine to prevent lytic plasma membrane damage, Caf measured with mag-fura-2 exceeded 10 microM in 91% of tubules studied and 68% had increases to greater than 100 microM. Caf increases of similar magnitude that were dependent on influx of medium Ca2+ were also seen using the new low Ca2+ affinity, Mg2+-insensitive, fluorophore fura-2FF in tubules depleted of ATP by hypoxia, and these increases were reversed by reoxygenation. Total cell Ca2+ levels in antimycin-treated or hypoxic tubules did not change, suggesting that mitochondria were not buffering the increased Caf during ATP depletion. Considered in the context of the high degree of structural preservation of glycine-treated tubule cells during ATP depletion and the commonly assumed Ca2+ requirements for phospholipid hydrolysis, actin disassembly, and Ca2+-mediated structural damage, the remarkable elevations of Caf demonstrated here suggest an unexpected resistance to the deleterious effects of increased Caf during energy deprivation in the presence of glycine.

Adenosine Triphosphate↗
PubMed1997

Prediction of normal values for lactate threshold estimated by gas exchange in men and women.

Lactate threshold (LT) is an index of exercise capacity and can be estimated from the gas exchange consequences of a metabolic acidosis (LT(GE)). In recent years, it has emerged as a diagnostic tool in the evaluation of subjects with exercise limitation. The purpose of this study was to develop LT(GE) prediction equations on a relatively large sample of adults and to cross-validate each equation. A total of 204 healthy, sedentary, nonsmoking subjects (103 men and 101 women), aged 20-70 years, underwent graded exercise testing on a cycle ergometer. The V-slope technique was used to detect LTGE as the oxygen uptake (VO2) at the breakpoint of the carbon dioxide output versus VO2 relationship. Multiple linear regression was used to develop 12 equations with combinations of the following predictor variables: age, height, body mass, and fat-free mass. Eight of the equations are gender-specific and four are generalized with gender as a dummy variable. The equations were cross-validated using the predicted residual sum of squares (PRESS) method. The results demonstrate that the equations had relatively high multiple correlations (0.577-0.863) and low standard errors of the estimate (0.123-0.228 1 x min(-1)). The PRESS method demonstrated that the equations are generalizable, i.e., can be used in future studies without a significant loss of accuracy. Since we tested only healthy, sedentary subjects, our equations can be used to predict the lower limit of normal for a given subject. Using individual data for healthy and diseased subjects from the literature, we found that our gender-specific equations rarely miscategorized subjects unless they were obese and mass was a predictor variable. We conclude that our equations provide accurate predictions of normal values for LT(GE) and that they are generalizable to other subject populations.

Adult↗
PubMed1997

Metabolic effects of troglitazone in the Goto-Kakizaki rat, a non-obese and normolipidemic rodent model of non-insulin-dependent diabetes mellitus.

Troglitazone (TRG) is an orally active antidiabetic agent that increases insulin sensitivity in models of non-insulin-dependent diabetes mellitus (NIDDM), subsequently reducing hyperinsulinemia and hyperglycemia. We examined the effects of TRG on the development and severity of diabetes in the Goto-Kakizaki (GK) rat, a spontaneous, non-obese model of NIDDM. TRG was administered at a dose of 30 mg/kg/d beginning at 4 weeks of age. TRG-treated GK rats were evaluated against Wistar and untreated GK rats at 8, 12, and 16 weeks of age. Untreated GK rats were nonketotic, normolipidemic, hyperglycemic, and had normal fasting insulin levels compared with Wistar rats. TRG treatment decreased glycosylated hemoglobin levels in the GK rat independently of its effects on plasma insulin. In untreated GK rats, intravenous glucose tolerance tests (IVGTTs) showed a hyperglycemic response to glucose loading with severely impaired glucose disposal relative to Wistar controls. TRG treatment was successful in decreasing the glucose area under the curve (AUC) (P < .03) but did not improve glucose disposal, suggesting a direct hepatic effect. Ex vivo evaluation of hepatic glucose output (HGO) further supported a direct hepatic action, with 50% reduction in HGO in TRG-treated GK rats (P < .004). A euglycemic-hyperinsulinemic clamp performed at 16 weeks of age showed severe insulin resistance in the untreated GK rat, with a glucose infusion rate (GIR) 33% lower than in Wistar rats (P < .004). TRG treatment had no effect on this insulin resistance. These results indicate that TRG selectively decreases hepatic glucose production in this unique model of NIDDM independently of its action on peripheral insulin sensitivity or hyperlipidemia.

Animals↗
PubMed1997

Endometrial status in post-menopausal women on long-term continuous combined hormone replacement therapy (Kliofem). A comparative study of endometrial biopsy, outpatient hysteroscopy and transvaginal ultrasound.

Forty post-menopause women using a preparation of 2 mg 17 beta-oestradiol and 1 mg norethisterone acetate (Kliofem) for a mean duration of 2.9 years were investigated in an open, prospective, method comparison study. Main outcome measures were the histology of endometrial biopsy in comparison with clinical evaluation of the endometrium during panoramic hysteroscopy and endometrial thickness measured by transvaginal ultrasound. Thirty-six women had either an inactive atrophic or unassessable endometrial biopsy, the remaining four (10%) showed benign endometrial changes. In the majority of patients the endometrium had a thin and regular appearance on hysteroscopy (92.5% of cases) with an endometrial thickness not exceeding 7 mm (90% of cases). Non-agreement between histology and hysteroscopy or transvaginal ultrasound findings was associated with the presence of polyps and submucosal fibroids, or innocuous endometrial changes such as a pseudodecidual pattern. No case of malignancy was encountered in any patient in this study. The present study suggests that continuous combined hormone replacement therapy appears to be safe with regard to endometrial health. In the majority of women an inactive endometrium or non-assessable biopsy result will be encountered. However, the numbers examined here are small and endometrial carcinoma has been reported to occur. Continuing follow-up of patients on continuous combined HRT is therefore essential.

Adult↗
PubMed1997

Stalkers and other obsessional types: a review and forensic psychological typology of those who stalk.

Stalking, an age-old phenomenon, was discussed in the ancient writings of Hippocrates, researched extensively in the early 20th century by French psychiatrist G.G. de Clerambault, given notoriety with the tragic death of former Beatle John Lennon, and viewed as 'Fatal Attraction' in local theaters across the world. Stalking is unique as the repetitive, harassing, long-term course of conduct and behaviour reflects the internal dynamics of the stalker's motivating mental disorder. Furthermore, the investigation of stalking is difficult. The numerous and progressive acts, comprising the intentional course of conduct, require a continuity of purpose: harassment designed to control the victim. A multi-disciplinary approach, utilizing law enforcement, legal, medical and mental health professionals, is necessary to effectively eradicate this encroaching behaviour. In 1990, the first Anti-Stalking legislation was passed in California, USA. In just 6 years, all 50 states have followed suit. Public awareness has encouraged federal legislation to stop stalking behaviour as a course of conduct crime and to give victims a measure of protection. This research paper overviews periodicals, law review articles, studies and projects of law enforcement, legal counsel, medical professionals, forensic mental health professionals, forensic examiners and criminologists since 1992. The study of stalkers and stalking behaviour is a work in progress. As questions are answered, statutes are amended and diagnoses are distinguished, it becomes a stepping stone to the future understanding of the pervasive stalking phenomenon facing our culture and society today.

Journal Article↗
PubMed1997

Glycine-protected, hypoxic, proximal tubules develop severely compromised energetic function.

Glycine-treated, hypoxic, proximal tubules developed a progressive energetic defect that resulted in failure to restore ATP levels to greater than 10 to 20% of control values during reoxygenation after 60 minutes of hypoxia despite continued cytoprotection by glycine. The defect was not corrected by supplementation with exogenous purines and was not modified by lowering the pH during hypoxia or reoxygenation. In the continued presence of glycine, the failure to restore ATP was associated with impaired recovery of structural changes that developed during hypoxia and, if glycine was withdrawn, lethal membrane damage occurred. The lesion was significantly ameliorated by the presence during hypoxia of two agents known to suppress development of the mitochondrial permeability transition, cyclosporine A and butacaine, which were most effective when used in combination. The data suggest that development of the mitochondrial permeability transition in glycine-protected tubules during hypoxia contributes to continued metabolic and structural impairment and cell death that occur despite glycine replete conditions such as exist frequently during in vivo insults and may be a target for therapeutic maneuvers.

4-Aminobenzoic Acid↗
PubMed1996

Role of Olf-1 and Pax-6 transcription factors in neurodevelopment.

The Olf-1 transcription factor is expressed in olfactory sensory neurons where it regulates the expression of genes that encode components of the odorant signal transduction cascade and contributes to the terminal phenotype of these sensory neurons. We examined the pattern of expression of Olf-1 protein during mouse embryogenesis and observed Olf-1 expression transiently in a subset of neural precursor cells in the CNS and peripheral nervous system. The expression of Olf-1 protein was enriched in sensory components and coincided with postmitotic cells and the initiation of overt differentiation within the nervous system. The spatial and temporal patterns of Olf-1 expression during development suggest a role in neurogenesis that is common among different neural cell types. In parallel, the expression pattern of Pax-6, a transcription factor that is widely expressed in the developing nervous system, including the visual and olfactory systems, was examined with a C-terminal antibody. In the retina, Pax-6 protein is detected in the lens, the cornea, and the neural and pigmented retinas. In the olfactory epithelium, Pax-6 protein is expressed exclusively in cells of non-neuronal lineage, including sustentacular cells, basal cells, and Bowman's glands. The nonoverlapping, cellular localization patterns of Pax-6 and Olf-1 demarcate distinct cell lineages within the developing olfactory epithelium.

Aging↗
PubMed1996

Sensitivity of Daphnia carinata sensu lato to the insect growth regulator, pyriproxyfen.

This paper reports the sensitivity of Daphnia carinata sensu lato to pyriproxyfen, a promising chironomid control agent. Neonates exposed to pyriproxyfen in acute toxicity trials produced 48-hr LC50 of 0.08 ppm, eight times the concentration known to control the emergence of nuisance chironomids. However, continuous exposure to pyriproxyfen (0.01 ppm) during a 3-brood, 14-day life cycle test, suppressed the growth of D.carinata and reduced reproduction by as much as 80%.

Analysis of Variance↗
PubMed1996

Sadness, tragedy and mass disaster in Oklahoma City: providing critical incident stress debriefings to a community in crisis.

Shortly after 09:00 h on 19 April 1995, the Alfred P. Murrah Federal Building, located in downtown Oklahoma City, was devastated with a bomb blast of such gigantic proportions that it was heard 60 miles away in neighbouring Norman, Oklahoma. Oklahomans routinely commuting to work on that sunny Wednesday morning went about their business as usual. A crude bomb chemically comprised of various organic compounds, chemical fertilizer, ammonium nitrate and diesel fuel, weighing an estimated 4800 pounds or more, was transported in a vehicle the size of a truck. It blew open a crater 6-8 ft deep in the street floor. The Murrah Federal Building was impacted immediately; floors, windows, communication equipment and almost all the innocent victims inside were razed to the ground. Outside the building, as far as 10 blocks away or more, hundreds of victims lay hurt, seriously injured or dead from shards of glass that flew from office windows hundreds of feet above the street floor. Without warning, the initial impact of the bomb immediately devastated the entire city. People were in a state of shock, disbelief and denial; acute symptoms of post traumatic stress disorder (PTSD) were commonplace. Oklahomans, 'numb' from the impact of the critical incident and ill-equipped to handle the chaos of such catastrophic proportions, struggled to regain control of their lives as friends, family and loved ones went unaccounted for or were found critically injured, dying or already dead. The critical incident on 19 April demanded the immediate attention of the nation, to come to the aid of the Oklahomans who were in desperate need. By 1 June, the exhaustive investigations revealed that 30 office buildings in downtown Oklahoma City had to be condemned, and as many as 300 others were damaged. In addition, 168 people had been found dead including 19 children and one nurse working as an emergency services rescue worker. Approximately 490 other victims had been reported injured from the blast. Countless others have been traumatised by the critical event and will need professional attention and care for weeks, months and years to come. The final extent of the impact on Oklahoma City is yet unknown and may never realistically be estimated in terms of personal trauma, loss and grief.

Crisis Intervention↗
PubMed1996

Gender differences in family attitudes about schizophrenia.

Recent studies have found that the expressed emotion (EE) status of relatives of female schizophrenics may not possess the prognostic value found previously for male schizophrenics. In the present study, relatives of 110 recent onset schizophrenic patients were assessed using the Camberwell Family Interview (CFI-EE), the Five Minute Speech Sample Method (FMSS-EE) and a measure of Affective Style (AS) to determine whether affective attitudes or behaviours varied by patient gender. Brief Psychiatric Rating Scale (BPRS) ratings made during in-patient and out-patient periods were examined to assess patient symptomatology. No differences were found by patient gender for CFI-EE, FMSS-EE, or subcomponents of the CFI-EE measure. However, when the subcomponents on the FMSS associated with a high EE critical rating were examined, males were found to be recipients of more harsh criticism than female patients. Similarly, for the AS measure, there was a distinct subgroup of male patients who received a level of criticism not seen in female patients. When the concordance across the two EE measures was examined, relatives of males were more consistent in their affective attitudes than relatives of female patients. Analysis of the BPRS data from the in-patient to the out-patient periods suggested variations by patient gender which may explain some of the differences in relatives' affective attitudes.

Adolescent↗