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Biomedical subjects

B A Gray

Publications and source records attributed to B A Gray.

At least 55 records · Page 3Linked to original sources
PubMed1984

Similarities and differences in black men and women in psychotherapy.

A survey of 93 psychiatrists concerning the psychotherapy of black men and women indicated that there were more similarities than differences between the men and women. Black male patients aged 31 to 40 and black women in the age ranges from 26 to 30 and 31 to 40 were most frequently seen for treatment. The patients were usually married and employed in technical or semiprofessional occupations. Both men and women had depression as the most frequent presenting problem, with work-related and family problems the next most frequent presenting problems.Black men were most often diagnosed as having affective (nonpsychotic) disorders, with anxiety disorders the second most frequent diagnosis. The reverse was true for women. Black men had aggression/passivity as the most frequent unconscious conflict and high/low self-esteem as the second. Again, the order of frequency was reversed for women. For both the men and the women, the psychiatrists felt racism was an important issue to consider in the treatment process and found that rage was related to racism.

Adult↗
PubMed1983

Manic-depressive illness among poor urban Hispanics.

Manic-depressive illness is reported to occur infrequently among some racial or ethnic groups and among lower socioeconomic groups. The authors investigated the incidence of manic-depressive illness among a random sample of 90 lower socioeconomic Hispanic patients admitted to the psychiatric inpatient unit of an urban hospital. They made a retrospective diagnosis based on DSM-III criteria and independent of the hospital diagnosis. Ten patients (11%) were diagnosed as manic-depressive--a rate three times the national admission rate. The authors discuss the significance of this finding and its relationship to sociocultural aspects of the Hispanic patient.

Adult↗
PubMed1982

Canine thoracic electrical impedance with changes in pulmonary gas and blood volumes.

The purpose of this study was to evaluate transthoracic impedance (Z) as an index of total lung liquid content at constant lung gas volume (LGV). To this end we produced rapid changes in pulmonary blood volume (PBV) in anesthetized, paralyzed, closed-chest dogs with the airway occluded at functional residual capacity. Changes in PBV produced by inflation of balloons on catheters positioned in the left atrium (LA) or inferior vena cava (IVC) were estimated from the changes in chest wall recoil pressure, using the chest wall as a plethysmograph after calibration with changes in LGV. Whereas Z increased linearly with decreases in PBV (1-6 ml/kg) produced by the IVC balloon (% delta Z/delta PBV = -0.43 ml/kg, r = -0.81), Z did not change significantly with increases in PBV (1-6 ml/kg) produced by the LA balloon. These observations indicate that changes in PBV are not the primary determinant of changes in Z and raise the possibility that other hemodynamic events are more important. Whereas aortic pressure decreased with both IVC and LA balloon inflations, right atrial pressure (Pra) increased with mitral valve obstruction and decreased with IVC obstruction. Changes in chest wall blood volume in response to changes in Pra could explain the changes in thoracic impedance. Thus, even at constant LGV, events in the systemic circulation appear to invalidate Z as an indicator of lung liquid content.

Animals↗
PubMed1982

Effect of atelectasis and embolization on extravascular thermal volume of the lung.

The extravascular volume of distribution for heat in the lung has been advocated for the measurement of lung water. The purpose of these experiments was to investigate how extremes of ventilation-perfusion mismatch influence this measurement. Twenty-six dogs were studied with right and left atrium-to-aorta thermal and dye-dilution curves before and 60 min after total right main-stem bronchial obstruction or microembolization of the pulmonary circulation with 0.275-mm glass beads. Whereas atelectasis had no influence on our measurements, embolization with 0.32 g/kg of beads decreased the detected pulmonary blood volume from 10.63 to 8.55 ml/kg and increased the extravascular thermal volume (ETV) from 9.89 to 10.99 ml/kg. Embolization with 0.65 g/kg decreased the detected ETV from 9.29 to 8.38 ml/kg, while the extravascular wet-to-dry weight ratio was increased, and the regression of postmortem extravascular mass on ETV differed from control. We conclude that microembolization but not atelectasis causes errors in the measurement of lung fluid when the thermodye technique is used. The errors are variable and depend on the degree of embolization.

Animals↗
PubMed1982

Acute and long-term ventilatory effects of hyperoxia in the adult sleep apnea syndrome.

Eight adult patients with sleep apnea were studied to evaluate the ventilatory and cardiac effects of hyperoxia on an acute basis. Five patients then used low-flow nighttime oxygen for 30 to 90 days. The results of the acute study showed that for 30-min study periods, the total number of apneas and per cent apnea time (duration of apneas divided by sleep time) decreased significantly from the room air to the oxygen period (207 to 68, p less than 0.05; 41.1 +/- 18.3% SD to 20.5 +/- 14.4%, p less than 0.05, respectively). Also, the apnea-associated slowing in heart rate is blocked by the supplemental oxygen. Three patients receiving oxygen at home decreased their per cent apnea time by greater than 60%. These patients also responded to the acute administration of hyperoxia by a decrease in apnea time greater than 60%. One patient prolonged the apnea time, and one had a minimal positive response, both again reflecting their acute studies. These data suggested that the severe hypoxemia that develops during an apnea in this syndrome has a central ventilatory effect that propagates the apneas and is significantly reversed by hyperoxia.

Adult↗
PubMed1982

The clinical picture of mania in manic-depressive black patients.

Recent studies have shown that misdiagnosis of manic-depressive illness among blacks is a frequent occurrence. There are a number of historical and institutional dynamics involved in this process that have the roots of racism as their foundation. In light of this the authors decided to look at the clinical symptoms and behaviors of manic-depressive illness among black patients to see if their interpretation might be another contributing factor in misdiagnosis.The authors found the clinical symptoms of manic-depressive illness in black patients to be essentially what one would expect as determined by criteria in the Diagnostic and Statistical Manual (DSM III). However, there were cultural and socioeconomic determinants of behavior that affected the clinical manifestations.

Adult↗
PubMed1981

Role of platelet serotonin in the canine pulmonary response to endotoxin.

There is evidence suggesting a role for platelet serotonin (5-HT) in the immediate pulmonary response to endotoxin in the dog (J. Appl. Physiol. 23: 47, 1967). To further define this role, autologous canine platelets were labeled with 5-[14C]HT in vitro and then reinfused. Subsequently Escherichia coli endotoxin (0.55:B-5, Difco), 2.5 mg/kg, was injected. Within 5 min dynamic compliance (CL) fell by more than 50%, and nonelastic resistance (RL) increased by more than 200%. Despite a 95% decrease in platelet count, less than 10% of the platelet 5-HT was released as determined by changes in the radioactivity of platelet-poor plasma (PPP) prepared from both aortic and pulmonary artery blood. As a positive control, injected of bovine collagen produced a similar decrease in platelet count that was associated with a significant increase in the radioactivity of aortic and pulmonary artery PPP. FInally, rapid injection of a dose of 5-HT equivalent to 25% of the 5-HT in circulating platelets did not cause a change in CL or RL equivalent to that produced by endotoxin. From these data we conclude that endotoxin injection does not cause immediate massive platelet activation and that platelet 5-HT does not play a major role in the immediate pulmonary response to endotoxin.

Animals↗
PubMed1981

Effect of methysergide on the acute lung mechanics response to endotoxin.

The effect of the serotonin antagonist methysergide on the acute lung mechanics response to endotoxin in anesthetized, paralyzed, mechanically ventilated dogs was investigated. In five dogs given 0.25 mg/kg Escherichia coli endotoxin only, the pulmonary nonelastic resistance (RL) increased to 238% of control and dynamic compliance (CL) decreased to 50% of control. In a second group of five dogs, methysergide (0.25 mg/kg) was shown to markedly attenuate the lung mechanics response to serotonin (0.04 mg/kg), which alone had produced changes in lung mechanics greater than endotoxin. In these same dogs endotoxin administered after injection of methysergide produced an increase in RL to 377% and a decrease in CL to 33% of control. In a third group of five dogs whose lung mechanics response to serotonin was also greater than to endotoxin alone, endotoxin administered after injection of saline produced an increase in RL to 168% and a decrease in CL to 58% of control. Since the response to endotoxin after injection of methysergide exceeded the response after saline, we conclude that serotonin is not a mediator of the acute lung mechanics response to endotoxin.

Animals↗
PubMed1981

Role of pulmonary edema in the acute pulmonary response to sepsis.

There is evidence that both bronchoconstriction and accumulation of lung water may contribute to the early alterations in lung function following septicemia. Eigher of these may be mediated by blood components. To assess these proposed mechanisms the changes in hemodynamics, pulmonary mechanics, gas exchange, and gravimetric lung water were measured in the first 4 h after Escherichia coli infusion in the anesthetized dog and baboon. These species were selected because of previously demonstrated differences in the response to gram-negative sepsis. Both species developed systemic hypotension and early hypoxemia. The dogs had early transient increases in venous admixture (Qva/Qt) but not shunt or dead space, while the baboon had a more persistent increase in Qva/Qt and a late increase in dead space, Increases in nonelastic resistance and decreases in lung compliance were preceded or accompanied by decreases in the leukocyte count in both species, but the platelet count, fibrinogen, and total hemolytic complement had different changes in the two species. Postmortem lung analysis revealed increased lung weight in both species but the wet weight-to-dry weight ratio was not increased in either species. The fractional water content of the excess lung mass was less than that of whole blood. Histological examination revealed large numbers of extravasated leukocytes in the lungs, which may be sufficient to explain the increase in lung weight. We conclude that pulmonary edema does not play a role in the early pulmonary response to E. coli bacteremia in either species. The physiological changes observed are more consistent with bronchoconstriction.

Animals↗
PubMed1981

Lymphocyte infiltration of gut epithelium in fetal and neonatal rabbits.

Lymphocytes infiltrate the epithelium of small intestinal villi of fetal rabbits as early as day 28 of gestation. They appear within the lateral spaces between the columnar absorptive cells. At this time, the epithelial cells transport compounds, such as injected horseradish peroxidase, through these intercellular spaces to the subjacent lamina propria. The possibility for in utero interaction between intraepithelial lymphocytes and antigen in swallowed amniotic fluid is discussed. There is an increase in the number of intraepithelial lymphocytes from 1 per 500 epithelial cells on day 1 to 16 per 500 epithelial cells on day 21 of postnatal life. Each segment, duodenum, jejunum and ileum, shows an increase in the number of lymphocytes during this period.

Aging↗
PubMed1981

Effect of inspiratory flow rate on gas exchange during mechanical ventilation.

We studied the effect of changes in inspiratory flow rate (VI) on gas exchange and respiratory system mechanics during mechanical ventilation. Seven patients with respiratory failure caused by severe chronic airway obstruction (CAO group) and 6 patients with other causes of respiratory failure (ORF group) were studied at 3 VI settings, 40 L/min, 70 L/min, and 100 L/min. In the CAO group, as VI increased from 40 L/min to 100 L/min, arterial oxygen tension increased 18%, venous admixture decreased 23.2%, dead space to tidal volume ratio decreased 23.7%, and tidal compliance of the respiratory system increased 31.2%. In the ORF group, as VI increased, there was little change in most parameters measured. The changes in the CAO group may be explained by redistribution of ventilation to low ventilation-perfusion ratio units, which empty more completely during the longer expiratory times allowed at high VI. Using a simple two-compartment lung model we determined that an increase in expiratory time from 4.2 to 6.1 s (the increase observed in the CAO group as VI increased from 40 L/min to 100 L/min) will result in redistribution of ventilation to long expiratory time constant respiratory units and produce changes in lung mechanics and gas exchange similar to those observed experimentally. We concluded that mechanical ventilation at high VI in patients with CAO is associated with improvement in gas exchange and more even distribution of ventilation, which appear to be due to the increased time available for alveolar emptying.

Aged↗
PubMed1981

Manic-depressive illness among poor urban blacks.

In psychiatric epidemiology it has generally been accepted that manic-depressive illness rarely occurs among blacks and lower socioeconomic groups. The authors conducted a retrospective study to examine the frequency of manic-depressive illness among lower income urban blacks admitted to an acute psychiatric inpatient unit of an urban hospital. The medical records of a random sample of 117 black psychiatric patients were reviewed for determination of manic-depressive illness as well as socioeconomic characteristics. Eighteen subjects (15%) were diagnosed as manic-depressive. The authors present possible explanations for this finding and the ramifications for future investigations.

Adult↗