Methotrexate therapy for hearing loss in Cogan's syndrome.
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Adult↗
Biomedical subjects
B Richardson
Publications and source records attributed to B Richardson.
Right hemisphere involvement in processing later-learned languages in multilinguals.
In two experiments, multilingual Papua New Guinean subjects were tested using a divided visual field technique designed to determine hemispheric laterality for English and for Tok Pisin. Various factors including age of acquisition, proficiency, mode of instruction, and number of years that the language had been used were considered in relation to language laterality. Only age of acquisition proved to be a significant contributor to the laterality effects obtained; older acquirers of both English and Tok Pisin showed greater right hemisphere involvement than early acquirers. Although proficiency did not seem to be related to language laterality, it too was systematically affected by acquisition age. Older acquirers of English performed significantly poorer than younger acquirers on all four of the language-usage tests given. The strong influence of acquisition age on cerebral laterality for language and proficiency is interpreted as supporting a critical period for language learning.
Adolescent↗
Neuropathology of the near-term and midgestation ovine fetal brain after sustained in utero hypoxemia.
OBJECTIVE: The neuropathologic mechanisms of the ovine fetal brain in response to several hours of sustained hypoxemia with variable degrees of metabolic acidemia was investigated in both the preterm and near-term ovine fetus. STUDY DESIGN: Three groups of fetuses were studied in each of the near-term and midgestation groups: a hypoxic group, a control group, and an uninstrumented control group. Histopathologic studies were performed after a 40-hour recovery period after experimentation. RESULTS: Pathologic findings consisted of predominately white matter damage with some adjacent cortical necrosis but no selective neuronal injury. In the near-term group the hypoxia group fetuses demonstrated significantly higher white matter injury scores than did control group fetuses (p < 0.05). Periventricular white matter injury was the predominant pattern seen in the midgestation group. CONCLUSIONS: In spite of normalization of biophysical and biochemical parameters after hypoxemia both midgestation and near-term fetuses sustained pathologic changes. Presence or extent of injury did not correlate with the degree of hypoxemia or metabolic acidosis achieved.
Acidosis↗
Recovery of the ovine fetus from sustained hypoxia: effects on endocrine, cardiovascular, and biophysical activity.
OBJECTIVE: The purpose of this study was (1) to determine the ability of the ovine fetus to recover from a self-limiting asphyxial insult and (2) to monitor cardiovascular and biophysical activity as potential markers of such an insult or underlying neurologic impairment. STUDY DESIGN: Nineteen fetal sheep were studied (12 hypoxia and 7 control) at 0.9 of gestation during a 24-hour control period, up to 8 hours of either sustained hypoxemia or room air, and for a 40-hour recovery period. Fetal heart rate, blood pressure, electrocortical activity, electroocular activity, and breathing movements were monitored continuously. Fetal arterial blood was sampled at set times for blood gases, pH, lactate, and catecholamine levels. RESULT: Induced fetal hypoxemia resulted in a lactic metabolic acidosis that progressively worsened, with death occurring in three of the animals during the early recovery period. The remaining animals showed a rapid metabolic and endocrine normalization of values by 24 hours. Fetal cardiovascular and biophysical measurements likewise returned to control values during the early recovery period, although three animals had seizure-like activity. CONCLUSION: The near-term ovine fetus surviving a sustained asphyxial insult sufficient to induce neuropathologic change within the brain demonstrates a normalization of biophysical activity during the early period of recovery, although seizure-like activity may subsequently be evident.
Animals↗
Cerebral metabolism during sustained hypoxemia in preterm fetal sheep.
OBJECTIVE: The purpose of this study was to determine the effect of sustained hypoxia with resulting metabolic acidosis on cerebral metabolism in the preterm ovine fetus. STUDY DESIGN: Twelve fetal sheep were studied at 0.75 of gestation during a normoxic control period, after 1 and 8 hours of sustained hypoxemia, and again after a 1-hour recovery period. Cerebral arteriovenous differences were analyzed for oxygen content, blood gases and pH, glucose, and lactate. Cerebral blood flow was measured with the microsphere technique. RESULTS: Induced hypoxemia resulted in a variable degree of fetal acidemia that was entirely metabolic. Although cerebral oxidative metabolism was well maintained throughout the study, cerebral glucose consumption was variably increased when measured after 1 hour of sustained hypoxemia, with a subsequent decrease after 1 hour of recovery. Although lactate was neither consumed nor produced during the control period, by 8 hours of hypoxic study a significant efflux of lactate from the brain was evident, which continued into the recovery period. CONCLUSION: Sustained hypoxemia results in an increase in the anaerobic metabolism of glucose by the preterm fetal brain independent of any change in cerebral oxidative metabolism, which may give rise to an accumulation of lactic acid and contribute to neurologic impairment.
Animals↗
Hypertrophic osteopathy in rats following chronic administration of SDZ MNS 949, an isoquinoline.
SDZ MNS 949, 6,7-dimethoxy-3-methyl-1-(3',5'-bis (methoxyethoxy) phenyl)-isoquinoline, a bronchodilating anti-inflammatory drug that inhibits phosphodiesterase, had been proposed for the treatment of bronchial asthma. Groups of 14 male and 14 female Wistar rats were administered doses of 12, 50, and 130 mg/kg/day in feed for 26 weeks. Periodic radiographic examinations were performed in addition to clinical observations, clinical chemistry measurements and urinalysis. At study termination full necropsy and histopathological examinations were performed on all animals. The principal clinical signs observed were unilateral edematous, red and painful swelling of the distal hindlimbs in 8 of 28 high dose animals, and abdominal swelling in 19 of 28 high dose animals. At radiographic examination periosteal new bone formation was predominantly along the tibia. Lesions at necropsy included dilated small and large intestines. Microscopically, enteritis was observed, and the periosteal new bone formation was confirmed. Hematological findings consisted of thrombocytosis and lymphocytosis, especially in high dose animals. The clinical, radiographical and histological findings in treated rats were consistent with the diagnosis of "hypertrophic osteopathy" or "Marie's Disease".
Animals↗
The effect of glucose on Doppler flow velocity waveforms and heart rate pattern in the human fetus.
Twenty-four healthy pregnant women were studied between 36 and 40 weeks gestation to determine the effect of glucose on the Doppler flow velocity waveform in the cerebral and umbilical arteries of the human fetus near term. The Resistance Index (RI), as an index of vascular resistance, was calculated for the anterior cerebral, internal carotid and umbilical arteries during a fasting control period, 45 min and again at 120 min after a 50-g maternal oral glucose drink or an equivalent amount of water. Fetal heart rate (FHR) pattern as determined by FHR variability was monitored as a measure of behavioural state. The RI of both cerebral vessels was significantly lower after the glucose drink, while that of the umbilical artery was little changed subsequent to either of the drinks. However the FHR mean min range, as an index of long term FHR variability was significantly increased when measured 30 to 60 min after the glucose drink and controlling for this change removed the effect of glucose on the RI of the cerebral vessels. We conclude that glucose does have an indirect effect on the cerebral Doppler waveform indices of the human fetus which is mediated through induced changes in behavioural state.
Adolescent↗
Effects of sustained hypoxemia on the sheep fetus at midgestation: endocrine, cardiovascular, and biophysical responses.
OBJECTIVE: The purpose of our study was to examine the effects of induced hypoxia on endocrine, cardiovascular, and biophysical measurements of the ovine fetus at 0.6 (83 to 93 days) of gestation and to compare the fetal responses at this earlier gestation with those reported near term. STUDY DESIGN: Fourteen fetal sheep were studied (9 in the hypoxia group and 5 in the control group) at 0.6 of gestation during a 24-hour control period, 8 hours of either sustained hypoxemia or room air, and a 40-hour recovery period. RESULTS: Induced fetal hypoxemia resulted in a progressive lactic metabolic acidosis; however, all fetuses had recovered within 24 hours. The fetal endocrine response was variable with norepinephrine, the only measured hormone showing a significant hypoxia-related increase (p less than 0.05). Fetal heart rate and mean arterial blood pressure showed little hypoxia-induced change, although fetal heart rate was significantly increased over the first 2 hours (p less than 0.05). The percent time fetal breathing movements, electroocular activity, and nuchal muscle activity likewise showed little hypoxia-induced change. CONCLUSION: The cardiovascular and biophysical response of the preterm fetus to induced hypoxemia is thus much less pronounced than that of the older gestational-aged fetus; this difference may impact on survival and the success of antenatal assessment protocols.
Animals↗
Perinatal assessment of cerebral flow velocity wave forms in the human fetus and neonate.
The temporal relationship between changes in cerebral Doppler flow velocity wave forms, ductal patency, blood gases, and blood pressure during the transition from intrauterine to newborn life was assessed longitudinally in 16 healthy term fetuses and newborns. Doppler flow velocity wave forms were obtained from fetal cerebral arteries (anterior cerebral, internal carotid, and basilar) before birth, within 8 h after birth, and again at 24 and 48 h after birth. The resistance index was used as a measure of vascular resistance. The resistance index of the cerebral arteries studied increased significantly between the antenatal and 8-h study periods. This was followed by a significant decrease below fetal levels by the 24-h study period, with little change thereafter. We conclude that in the newborn human, as in the newborn lamb, the transition from fetal to immediate newborn life is associated with an increase in cerebral vascular resistance and thus a decrease in cerebral blood flow in response to the increase in arterial oxygenation. The subsequent decrease in the cerebral resistance index between 8 and 24 h of life cannot be explained by a loss of ductal shunting nor by associated changes in newborn blood gases or blood pressure, but may rather reflect a remodeling of the circulation due to impedance matching.
Blood Flow Velocity↗
The effect of carbon dioxide on Doppler flow velocity waveforms in the human fetus.
Twelve healthy pregnant women were studied between 35 to 40 weeks gestation to determine the effect of carbon dioxide on the Doppler flow velocity waveform in the cerebral and umbilical arteries of the human fetus near term. The Resistance index (RI), as an index of vascular resistance, was calculated for the internal carotid and umbilical arteries during a control period while patients breathed room air followed by three randomized 15-30 min study periods with patients breathing either room air, a prepared gas mixture with 2% carbon dioxide, or undergoing controlled hyperventilation as determined by monitoring end-tidal PCO2. The RI of the internal carotid and umbilical arteries both showed a significant inverse relationship to maternal end-tidal PCO2 with a greater negative slope for RI plotted against end-tidal PCO2 in the internal carotid artery (0.0153) than in the umbilical artery (0.0047). The change in the RI as an index of changing vascular resistance, suggests that carbon dioxide is also an important determinant of cerebral blood flow in the human fetus, as previously described for fetal sheep, with a lesser although significant effect on umbilical blood flow.
Blood Flow Velocity↗
Research: the bridge to collaboration.
A faculty-staff research fair was used by a school of nursing and university hospital at a large Southern medical center as a way of promoting collaboration between nursing education and service. The end results were these: a nurse-theorist "room" in the school of nursing; development of collaborative studies; subsequent presentation of posters originally prepared for the fair at 12 local, 13 state, six regional, and three national meetings. The overwhelming positive response by participants verified that research could serve as a natural bridge to promote collaboration between research, education, and service.
Faculty, Nursing↗
Correlation of squamous cell carcinoma antigen levels and treatment response in cervical cancer.
Squamous cell carcinoma antigen (SCC) was measured by serum radioimmunoassay in 82 patients with primary (55) or recurrent (27) squamous carcinoma of the cervix, to determine correlation with the clinical presence of tumor and response to radiation and chemotherapy. Sixty-seven percent of those with newly diagnosed cancer and eighty-one percent of those presenting with recurrence had values above 2.5 ng/ml. In the newly diagnosed patients, 17% of those with stage I and 80% of those with stages II and above had abnormal values. Mean titers for stages I through IV were 2, 9, 19, and 144 ng/ml, respectively, confirming an association with tumor burden. Twenty-four patients underwent radiation therapy; eighteen of these had elevated pretreatment levels and were assessed for response. Titers accurately predicted regression and progression in all cases. Thirty patients received chemotherapy; twenty-seven of them had elevated pretreatment levels and were evaluable for response correlation. Titers predicted response in 96% of cases. An additional group of 20 patients successfully treated and with no evidence of disease was followed with SCC levels every 3 months. In 19 of these 20 patients (95%), the marker accurately predicted the status of disease. In 2 of these patients, who recurred while on the study, the SCC level increased before the tumor became clinically apparent. We conclude that SCC levels are useful in evaluating the response of primary and recurrent squamous cell carcinoma of the cervix to radiation and chemotherapy.
Carcinoma, Squamous Cell↗
The interaction of behavioural state, heart rate and resistance index in the human fetus.
The association and possible interactions of fetal behavioural state, fetal heart rate and vascular resistance was studied in 23 healthy pregnant women between 36 and 40 weeks' gestation. Doppler flow velocity waveforms were obtained from fetal cerebral (anterior cerebral, internal carotid and basilar), descending aorta and umbilical arteries during fetal behavioural state 1F and repeated during 2F. The Resistance Index (RI) was used as a measure of vascular resistance. Decreased vascular resistance was observed in all vessels except the umbilical artery during fetal behavioural state 2F compared to 1F (P less than 0.001). A significant interaction was observed between fetal heart rate and fetal behavioural state on the RI of the vessels studied, with a greater negative slope for RI plotted against fetal heart rate in fetal behavioural state 2F (-0.00139) compared to 1F (0.00005) (P less than 0.001). We conclude that the transition from fetal behavioural state 1F to 2F is associated with a significant reduction in cerebral and systemic vascular resistance, with no apparent change in placental resistance. Furthermore, fetal behavioural state and fetal heart rate interact, demonstrating a stronger association of fetal heart rate and RI in fetal behavioural state 2F in keeping with an increase in baroreflex sensitivity at this time.
Behavior↗
Pressure sores--a manager's perspective.
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Humans↗
Evidence for impaired T cell DNA methylation in systemic lupus erythematosus and rheumatoid arthritis.
Procainamide and hydralazine inhibit T cell DNA methylation and induce autoreactivity in cloned CD4+ T cells. These drugs also induce an autoimmune syndrome, suggesting a possible relationship between DNA hypomethylation, T cell autoreactivity, and certain autoimmune diseases. To test this relationship, DNA methylation was studied in T cells from patients with rheumatoid arthritis and patients with systemic lupus erythematosus, and was found to be impaired. These results support a relationship between DNA hypomethylation and some forms of autoimmune disease.
Adult↗
Postwar mortality among Australian World War II prisoners of the Japanese.
The impact of detention as a prisoner of war on postwar survival and disease-specific mortality was examined in Australian veterans of World War II. A random sample of 908 ex-prisoners and 797 other veterans of the same theatre of war, all of whom had returned to Australia alive, was traced over the 40 years since the war. The date and cause of death were recorded for those who were found to have died. By means of the subject-years method, the mortality of the prisoners of war was compared with that of the non-prisoners of war while the analysis controlled for the length of follow-up and the subject's age at the close of the war. The prisoners of war showed a higher over-all mortality rate than did the non-prisoners of war. This difference was pronounced in the period from five to 14 years after the war but diminished subsequently. There also was an indication that this effect varied with the subject's age at the end of the war: prisoners of war who were aged 25-29 years at that time had the highest mortality differential from non-prisoners of war, followed by prisoners of war who were aged 30-34 years. However, log-linear modelling, which controlled for age and the follow-up period, did not suggest that these mortality differences could be attributed to particular causes of death.
Adult↗
Control of fetal breathing in the human fetus between 24 and 34 weeks' gestation.
The effect of induced maternal hypocapnia and hypercapnia on fetal breathing movements was studied in 30 healthy pregnant women between 24 and 34 weeks' gestation to determine whether gestational age influences the fetal respiratory response to alterations in carbon dioxide levels. The percent time of fetal breathing movements correlated significantly with maternal end-tidal PCO2, increasing with maternal breathing of 2% and 4% carbon dioxide and decreasing with maternal hyperventilation for each of the three gestational age groups studied. However, the slope of this response for the 28- to 30-week group (3.29) and for the 32- to 34-week group (3.66), although similar to that of the term fetus, was significantly greater than that for the 24- to 26-week group (1.18, p less than 0.001). We conclude that the carbon dioxide level in the preterm fetus (as in the term fetus) is an important stimulus for the generation of respiratory movements. However, a developmental change is evident; the 24- to 26-week fetus demonstrates a decreased respiratory response to tonic carbon dioxide input. This may account for the decreased incidence of fetal breathing movements in the fetus of younger gestational age.
Carbon Dioxide↗
Prompted voiding therapy for urinary incontinence in aged female nursing home residents.
A study of 85 incontinent female nursing home residents explored the effects of two nursing interventions (prompted voiding and socialization) on incontinence. Findings indicate that a controlled prompted voiding programme is useful in decreasing incontinent episodes. Positive effects of prompted voiding were noted over a 5-week experimental period. It is suggested that nursing homes incorporate prompted voiding into their care. Nursing homes adopting this protocol should be encouraged to keep data that will contribute further to knowledge in this area. Recommendations for additional research are made.
Aged↗