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Biomedical subjects

H M Rhoades

Publications and source records attributed to H M Rhoades.

At least 37 records · Page 2Linked to original sources
PubMed1990

Neuronal protection correlates with prevention of calcium-calmodulin binding in rats.

We correlated the efficacy of several clinically relevant pharmacotherapies with their ability to prevent calcium influx into neurons and subsequent binding to calmodulin. We studied the administration of CGS 19755, nimodipine, nicardipine, and combinations of these drugs before or immediately after ischemia in globally ischemic rats. Calcium-calmodulin binding was graded by an immunohistochemical assay after 2 and 24 hours of reperfusion (n = 5-6 at each time period), and histologic damage was graded by light microscopy after 72 hours of reperfusion (n = 6). Calcium-calmodulin binding correlated with the severity of delayed histologic damage in various brain regions. In untreated ischemic control rats, marked calcium-calmodulin binding was seen in CA1 and CA3 after 24 hours of reperfusion (p less than or equal to 0.01). Administered before ischemia, CGS 19755 prevented calcium-calmodulin binding across all brain regions after 2 and 24 hours of reperfusion compared with controls (p less than or equal to 0.05). This effect was most prominent in CA3 and CA1, where the drug also reduced delayed neuronal damage (p less than or equal to 0.05). Lower doses or postischemic administration of CGS 19755, nimodipine, nicardipine, and a combination of postischemic CGS 19755 and nicardipine had a more limited effect on calcium-calmodulin binding and did not protect against delayed neuronal damage.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Effects of language and ethnic status on reliability and validity of the Center for Epidemiologic Studies-Depression Scale with psychiatric patients.

Data from 562 psychiatric patients were analyzed to assess the effects of ethnic status (Anglo/Mexican origin) and language (English/Spanish) on the reliability and validity of the Center for Epidemiologic Studies-Depression Scale. The results indicate no systematic variation in either reliability (test-retest, internal consistency), dimensionality, or ability of the CES-D Scale to detect clinical depression among Anglos or persons of Mexican origin classified according to language use as Spanish dominant, English dominant, or bilingual. However, the data indicate that this particular screening instrument does not adequately discriminate between patients with clinical depression and those without depression. These results corroborate several recent studies that question the utility of the CES-D Scale as a depression screening instrument. Taken together, the available evidence suggests that the ability of the CES-D Scale to detect major depression is so limited that further use of the instrument as a screening scale would seem unwarranted, at least in treatment settings.

Analysis of Variance↗
PubMed1989

Effect of thromboxane synthase inhibition on eicosanoid levels and blood flow in ischemic rat brain.

Reperfusion of ischemic brain is associated with production of thromboxane A2 (TXA2), a proaggregatory vasoconstrictor. We used an animal model of transient forebrain ischemia to study the effects of 1-benzylimidazole (1-BI), a selective inhibitor of thromboxane synthase, upon cerebral eicosanoid levels and cerebral blood flow. Male Wistar rats were subjected to 30 minutes of four-vessel occlusion. The mean +/- SEM brain level of TXB2, the stable metabolite of TXA2, determined after 60 minutes of reperfusion was 101 +/- 20 pg/mg brain protein in five ischemic control rats. Infusion of 10 micrograms/g 1-BI reduced mean +/- SEM cerebral TXB2 concentration to 11 +/- 3 pg/mg brain protein in five rats (p less than or equal to 0.002). Mean +/- SEM hemispheric cerebral blood flow measured in four ischemic control rats after 60 minutes of reperfusion was 42 +/- 9 ml/100 g brain/min compared with 104 +/- 13 ml/100 g brain/min in three 1-BI-treated rats (p less than or equal to 0.001). Mean +/- SEM hippocampal blood flow in four ischemic control rats after 60 minutes of reperfusion was 51 +/- 14 ml/100 g brain/min compared with 125 +/- 25 ml/100 g brain/min in three 1-BI-treated rats (p less than or equal to 0.04). We conclude that selective inhibition of thromboxane synthase may alleviate ischemic brain damage by reducing cerebral TXA2 concentrations and elevating cerebral blood flow.

6-Ketoprostaglandin F1 alpha↗
PubMed1988

Regional depletion of adenosine triphosphate, phosphocreatine, and glucose in ischemic hippocampus.

The selective vulnerability of pyramidal neurons in the CA1 hippocampal region in ischemic rat brain may be preceded by regional alterations of energy metabolism during early reperfusion. We measured ATP, phosphocreatine (PCr), and glucose in paramedian and lateral CA1 and in an area showing little postischemic cell loss, CA2. ATP levels in paramedian CA1 were depressed immediately after 30 min of ischemia (P less than or equal to 0.02) and remained abnormal after 2 hr of reperfusion (P less than or equal to 0.05). PCr was reduced substantially in both subdivisions of CA1 immediately after ischemia (P less than or equal to 0.04) but returned to normal levels after 2 hr. Glucose levels were depressed in paramedian CA1 and CA2 after ischemia (P less than or equal to 0.02) but corrected with reperfusion. We determined approximately P, the sum of ATP and PCr, in separate experiments investigating regional differences in consumption of high-energy phosphate metabolites during complete ischemia. The approximately P levels of rats subjected to 30 min of reversible ischemia followed by 2 hr of reperfusion showed a different pattern of regional differences from those seen in sham-ischemic animals (P less than or equal to 0.01), indicating a persistent depression of metabolic rate in CA1 during reperfusion. We conclude that regional depletion of high-energy phosphates and alteration of metabolic rate may contribute to the selective vulnerability of the CA1 region during brain ischemia.

Adenosine Triphosphate↗
PubMed1988

Long-term outpatient treatment of senile dementia with oral physostigmine.

The authors describe five patients with senile dementia of the Alzheimer type (SDAT) who were treated with oral physostigmine from 1 to 3 3/4 years. An abbreviated form of the Buschke selective reminding test was used to assess the patients' short-term verbal memory at periodic clinic visits. Although one of the patients deteriorated progressively from the start of the physostigmine therapy and was taken off the drug after 1 year, there was no evidence of deterioration in memory performance on the average in the other four patients. Equally important, this open trial provides evidence of the safety of long-term treatment with physostigmine on an outpatient basis. The authors view their results as supporting the potential value of cholinesterase inhibition as a means of forestalling memory decline in SDAT patients.

Administration, Oral↗
PubMed1987

Rorschach assessment of borderline children.

Projective testing may provide the clinician with a valuable context in which childhood borderline conditions may be investigated. The purpose of this study was to determine if Rorschach scores could be useful in diagnosing borderline disorders. Rorschach scores from a group of 13 borderline children and 10 conduct disorder children were compared using a step-down discriminate analysis. The results indicated that children in these two groups could be correctly classified beyond chance levels using Rorschach scores. Three variable, content analysis, human movement, and animal movement were the strongest contributors in separating the two groups. The Rorschach measure of form quality (i.e., adequacy of perception) was notable in that it failed to produce any independent discriminatory power in this analysis. As in the case of adult borderline testing using the Rorschach, novel scoring procedures, used in conjunction with standard scoring procedures may lead to further clarification of childhood borderline disorders.

Borderline Personality Disorder↗
PubMed1987

The neurobehavioural rating scale: assessment of the behavioural sequelae of head injury by the clinician.

To investigate the inter-rater reliability and validity of the Neurobehavioural Rating Scale at various stages of recovery after hospitalisation for closed head injury, we studied 101 head trauma patients who had no antecedent neuropsychiatric disorder. The results demonstrated satisfactory inter-rater reliability and showed that the Neurobehavioural Rating Scale reflects both the severity and chronicity of closed head injury. A principal components analysis revealed four factors which were differentially related to severity of head injury and the presence of a frontal lobe mass lesion. Although our findings provide support for utilising clinical ratings of behaviour to investigate sequelae of head injury, extension of this technique to other settings is necessary to evaluate the distinctiveness of the neurobehavioural profile of closed head injury as compared with other aetiologies of brain damage.

Adolescent↗
PubMed1987

Computer-based monitoring of clinical care in a public psychiatric hospital unit.

A computer-based clinical monitoring system on a 40-bed university hospital psychiatric unit provides documentation to justify clinicians' diagnosis and choice of treatment and facilitates evaluation of patients' progress at scheduled intervals. The microcomputer system was developed to meet state guidelines for monitoring patients receiving neuroleptic drug treatment. A weekly status report generated for each patient alerts the treating physician to cases in which data do not justify clinical decisions, identifies potential problems, and suggests considering for discharge patients whose symptoms have sufficiently abated. The system is also useful in supervision and research.

Diagnosis, Computer-Assisted↗
PubMed1986

The Nurses Evaluation Rating Scale (NERS).

The Nurses Evaluation Rating Scale (NERS) consists of 16 items designed to capture salient dimensions of psychopathology and nursing care requirements for psychiatric patients. Reliability and validity of the NERS were evaluated by using a total of 3,052 sets of ratings accomplished by 19 staff nurses on a total of 235 adult psychiatric inpatients. All items of the NERS were utilized in describing psychopathology in this sample of patients, although no patient was positive on all items. Factor analysis revealed four distinct clusters of items, which represented higher-order constructs of thinking disturbance, depression, anxiety, and psychomotor retardation. Test-retest reliability was found to be comparable to the reliability of most other clinical assessments of psychopathology. Scoring for the four factors was defined, and analysis of change during first 10 days of hospital stay revealed statistically significant improvement. The NERS appears to be a promising instrument for longitudinal, daily evaluations of inpatient psychopathology as seen in the routine clinical practice of psychiatric nurses.

Factor Analysis, Statistical↗
PubMed1986

Cerebral glucose metabolism after portacaval shunting in the rat. Patterns of metabolism and implications for the pathogenesis of hepatic encephalopathy.

The regional cerebral metabolic rate for glucose was measured in normal and portacaval shunted rats and the effects of unilateral carotid infusions of "threshold" amounts of ammonia were assessed. 8 wk after shunting the glucose metabolic rate was increased in all 20 brain regions sampled. Effects on subcortical and phylogenetically older regions of the brain were most pronounced with a 74% increase observed in the reticular formation at the collicular level. Increases in the cerebral cortex ranged from 12 to 18%. Unilateral infusions of ammonia did not affect behavior but altered the electroencephalogram and selectively increased the glucose metabolic rate in the thalamus, hypothalamus, and substantia nigra in half of the animals, a pattern similar to that seen after a portacaval shunt, suggesting hyperammonemia as the cause of postshunt increases in glucose metabolism. Visual inspection of autoradiograms, computed correlation coefficients relating interregional metabolism, and principal component analysis suggest that normal cerebral metabolic and functional interrelationships are altered by shunting. Ammonia stimulation of the hypothalamic satiety centers may suppress appetite and lead to cachexia. Reductions in the ammonia detoxification capacity of skeletal muscle may increase the probability of developing future episodes of hyperammonemia, perpetuating the process. Direct effects of ammonia on specific brain centers such as the dorsomedial hypothalamus and reticular activating system may combine with global disruptions of cerebral metabolic-functional relationships to produce the protean manifestations of portal-systemic encephalopathy.

Acetates↗
PubMed1986

Central vs peripheral venous catheters in critically ill patients.

A prospective study of 2,209 intravenous catheters was performed in a multidisciplinary intensive care unit to determine when and why catheters were removed and which sites of insertion were associated with the least morbidity. Techniques of insertion were vigorously supervised. Central and peripheral catheters were cared for by identical protocols. Overt phlebitis or inflammation around the site was 14 times as common with peripheral catheters (353/1,024) than with centrally inserted central catheters (18/713), even though peripheral catheters were removed on the average at 2.9 days and centrally inserted central catheters at 6.2 days. Pneumothorax occurred in seven out of 713 patients with centrally inserted central catheterization, one with hemothorax and two with pneumothoraces requiring thoracostomy tubes. Five were treated successfully with simple catheter aspiration. Three patients out of 1,496 with peripheral or peripherally inserted central catheters required phlebectomy for suppurative thrombophlebitis. We concluded that overall morbidity in critically ill patients is lower from centrally inserted central catheters than peripheral intravenous catheters, with peripherally inserted central catheters in an intermediate position. Supervision of techniques of insertion has to be kept at a high level to keep complications of central catheterization at an acceptable level. Peripheral catheter sites would be better maintained with more frequent replacement of the catheter.

Catheterization↗
PubMed1985

Beta, or type II error in psychiatric controlled clinical trials.

Fifty-two reportedly "negative" psychiatric controlled clinical trials from 1980-1984 were re-examined to note if large enough samples had been studied to give a high probability (greater than 0.90) of detecting a 20% or 50% improvement in therapeutic response, defined as a reduction in the non-response rate. Forty-four of the trials had a larger than 10% risk of missing a true 20% difference in non-response rates, and with the same risk, 25 of the trials could have missed a 50% difference between treatments. Based on estimates of 90% confidence intervals, a potential 20% difference was possible for 47, and 30 had a potential true difference of 50% in non-response rates between experimental and control conditions. Far more reports describing "non-significant" studies could not be re-examined, due to lack of reporting part or all of the relevant results. The possibility of missing considerable therapeutic improvement, or important clinical differences, because of small sample size demands more concern in psychiatry.

Clinical Trials as Topic↗