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Biomedical subjects

M N Rashad

Publications and source records attributed to M N Rashad.

At least 19 recordsLinked to original sources
PubMed1992

Usefulness of right ventricular indices in early diagnosis of cardiac tamponade.

Early diagnosis of postoperative cardiac tamponade is impeded by its clinical similarity to left ventricular failure. Moreover, the hemodynamic changes necessary to diagnose cardiac tamponade are detected by conventional monitoring technique only after clinical compromise. Early signs of cardiac tamponade and left ventricular failure were studied with emphasis on right ventricular function in anesthetized dogs. One group (n = 20) had cardiac tamponade produced by incrementally increasing pericardial pressure (2 to 20 mm Hg), and another group (n = 20) had acute left ventricular failure produced by successive ligation of the anterior descending coronary artery at the lower, middle, and upper thirds. Besides standard hemodynamic measurements, right ventricular function was examined with a rapid-response thermodilution catheter. During cardiac tamponade, cardiac output, right ventricular ejection fraction, right ventricular stroke volume, and right ventricular end-diastolic volume were significantly decreased from baseline values after a pericardial pressure of 8 mm Hg or more (p less than 0.05). Right atrial and pulmonary arterial pressures were not significantly elevated until 14 and 20 mm Hg of pericardial pressure, respectively. Although cardiac function in the left ventricular failure group was reduced after each ligation, right ventricular ejection fraction remained unchanged. This study suggests that right ventricular indices may facilitate earlier diagnosis of cardiac tamponade with greater accuracy.

Animals↗
PubMed1991

Intrathecal morphine 0.2 mg versus epidural bupivacaine 0.125% or their combination: effects on parturients.

To compare the efficacy and side effects of 0.2 mg intrathecal (IT) morphine with 0.125% epidural bupivacaine, 62 women in labor were studied. They were randomly divided into three groups: group 1 (n = 20) received IT morphine; group 2 (n = 22) received epidural bupivacaine; and group 3 (n = 20) received a combination of both using a combined spinal-epidural (CSE) technique. According to a visual analogue scale for assessing analgesia, neither IT 0.2 mg morphine nor 10 ml 0.125% epidural bupivacaine was effective in producing adequate pain relief in labor, whereas the combination produced excellent analgesia. The use of IT morphine significantly reduced the dosage requirement of epidural bupivacaine. The incidence of nausea, vomiting, and pruritus was significantly higher when IT morphine had been administered, whereas that of urinary retention did not differ. No serious respiratory depression occurred in any of the patients. When the course of labor was studied, the prior use of IT morphine significantly prolonged the duration of the first stage of labor and the total duration of labor. We conclude that the administration of 0.2 mg IT morphine in combination with epidural administration of 0.125% bupivacaine provides better analgesia than the administration of either drug alone.

Adult↗
PubMed1989

Assessing acid-base status in circulatory failure. Differences between arterial and central venous blood.

To assess arteriovenous differences in acid-base status, we measured the pH and partial pressure of carbon dioxide (PCO2) in blood drawn simultaneously from the arterial and central venous circulations in 26 patients with normal cardiac output, 36 patients with moderate and 5 patients with severe circulatory failure, and 38 patients with cardiac or cardiorespiratory arrest. The patients with normal cardiac output had the expected arteriovenous differences: venous pH was lower by 0.03 unit, and venous PCO2 was higher by 0.8 kPa (5.7 mm Hg). These differences widened only slightly in those with moderate cardiac failure. Additional simultaneous determinations in mixed venous blood from pulmonary arterial catheters were nearly identical to those in central venous blood. In the five hypotensive patients with severe circulatory failure there were substantial differences between the mean arterial and central venous pH (7.31 vs. 7.21) and PCO2 (5.8 vs. 9.0 kPa [44 vs. 68 mm Hg]). Large arteriovenous differences were present during cardiac arrest in patients whose ventilation was mechanically sustained, whether sodium bicarbonate had been administered (pH, 7.27 vs. 7.07; PCO2, 5.8 vs. 8.6 kPa [44 vs. 65 mm Hg]) or not (pH, 7.36 vs. 7.01; PCO2, 3.7 vs. 10.2 kPa [28 vs. 76 mm Hg]). By contrast, in patients with cardiorespiratory arrest, large arteriovenous differences were noted only when sodium bicarbonate had been given (pH, 7.24 vs. 7.01; PCO2, 9.5 vs. 16.9 kPa [71 vs. 127 mm Hg]). We conclude that both arterial and central venous blood samples are needed to assess acid-base status in patients with critical hemodynamic compromise. Although information about arterial blood gases is needed to assess pulmonary gas exchange, in the presence of severe hypoperfusion, the hypercapnia and acidemia at the level of the tissues are detected better in central venous blood.

Acid-Base Equilibrium↗
PubMed1989

Arteriovenous acid-base disparity in circulatory failure: studies on mechanism.

The normal relationship between arterial and venous acid-base composition is altered in hemodynamic compromise. Because the mechanism of this phenomenon remains conjectural, we have studied the acid-base profile and the end-tidal PCO2 of dogs with normal or depressed hemodynamic status in association with either normal ventilation or respiratory arrest. Reductions in cardiac output widened the arteriovenous difference in PCO2 and pH, largely due to arterial hypocapnia but also to venous hypercapnia, and decreased end-tidal PCO2. The arteriovenous gradients for PCO2 and pH of -5.1 +/- 0.4 mmHg and 0.02 +/- 0.01, respectively, during normal hemodynamics widened progressively with graded circulatory compromise reaching values of -30 +/- 5 mmHg for PCO2 (P less than 0.01) and 0.35 +/- 0.05 for pH (P less than 0.01) during cardiac arrest. Development of this disparity, however, required the presence of substantial pulmonary ventilation, since respiratory arrest obliterated the arteriovenous gradients. We propose that arterial hypocapnia, which occurs in association with reduced CO2 excretion, is secondary to an increased ventilation-to-perfusion ratio that reflects a disproportionate decrement in cardiac output. Venous hypercapnia, on the other hand, results from a greater than normal addition of CO2 per unit of blood traversing the capillaries of the hypoperfused peripheral tissues and a diminished CO2 excretion because of pulmonary hypoperfusion. Titration of bicarbonate stores by ongoing production of organic acids might also contribute to venous hypercapnia.

Acid-Base Imbalance↗
PubMed1978

Parent-offspring resemblance for specific cognitive abilities in Korea.

Regressions of offspring on midparent value for tests of specific cognitive abilities in Korea were considerably higher than those for Americans of Japanese ancestry or Americans of European ancestry tested in Hawaii. This greater parent-offspring resemblance in Korea may be due to the particular method of test administration or to an increased genetic variance resulting from assortative mating. The pattern of parent-child correlations for three relatively pure tests of spatial ability and for the spatial factor did not conform to that of a sex-linked recessive character.

Adolescent↗
PubMed1978

Dermatoglyphic studies of myocardial infarction patients.

Dermatoglyphic traits were studied in a sample of 834 subjects selected from a cohort of some 8,000 living Japanese men, under a long-term study of heart disease in Hawaii. All of them were born between 1900 and 1919. Among them, 100 subjects had had positive diagnosis of myocardial infarction (MI). The present study included comparisons between the MI patients and the remaining group of all digital dermal pattern types and ridge counts by digit, by hand, and by individual. The MI patients had significantly higher frequency of true whorls, double loops and less ulnar loops and tented arches. Total and absolute ridge counts were significantly higher (less than 0.05) in all digits in favor of the MI patients. Similar trends were observed in analyses by digit and by hand. These observations suggest an antenatal origin of certain types of coronary disease.

Dermatoglyphics↗
PubMed1977

Genetics of asymmetry in dermatologlyphic traits.

Differences between the right and left hand in ridge counts and pattern type counts were analyzed using data obtained from 711 families consisting of all parents and 2,466 children. Heritability estimates for each trait were derived from regressions of offspring on either parent or average value of the two parents, and from full-sib correlations. These estimates varied from 0.09 for bimanual difference in the number of arches to 0.24 in the number of ulnar triradii. The low expected value of heritability for bimanual difference in dermatoglyphic traits was demonstrated.

Adult↗
PubMed1977

Association between renal function tests and pentachlorophenol exposure.

Data are presented and renal function tests and Pcp measurements on consecutive blood and urine samples collected from 18 workers at a wood treatment plant before, during, and after a 20-day vacation. Pcp concentrations in blood averaging 5.1 ppm before vacation fell to 2.2 ppm during vacation but with a temporary rise early in this nonexposure period, suggesting a body tissues store of Pcp which was mobilized in response to a negative Pcp balance. Urine Pcp concentrations showed similar but less marked variations. Creatinine clearance and phosphorus reabsorption values were depressed before vacation but showed significant improvement during vacation, suggesting that Pcp exposure reduced both glomerular filtration rate and tubular function, with recovery following a nonexposure period.

Chlorophenols↗
PubMed1975

Dermatoglyphic traits in patients with cardiovascular disorders.

Dermatoglyphic studies were carried out on 800 Japanese subjects. Digital dermal pattern types were classified into true whorls, double loops, ulnar loops, radial loops and arches. Both total and absolute ridge count were recorded. Subjects with hypertension, angina pectoris and myocardial infarction were compared with the remaining group of others who had not yet developed any of these disorders. Individuals with myocardial infarction had a significantly higher frequency of true whorls and a correspondingly lower frequency of ulnar loops than the control group. Total and absolute ridge counts were also significantly higher in myocardial infarction. Individuals with hypertension and angina pectoris were not significantly different in most dermatoglyphic traits from the controls. These observations suggest that antenatal factors may contribute to the etiology of myocardial infarction in man.

Angina Pectoris↗
PubMed1975

Genetic parameters of dermal patterns of ridge counts.

Dermatoglyphic traits including ridge counts and pattern type counts on fingers were studied in 711 families representing six racial groups in Hawaii. Heritability tesimates were derived from regressions of offspring on father, mother and mid-parent values as well as from full-sib correlations. These estimates varied from 0.23 for radial loops to 0.80 for total ridge count. The heritability estimates were lower for ridge counts of single hands or single digits.

Dermatoglyphics↗
PubMed1975

Cognitive abilities: use of family data as a control to assess sex and age differences in two ethnic groups.

Four cognitive factors were extracted from test data obtained on 997 families (3,268 individuals) in Hawaii. Factor loading profiles for the two largest ethnic groups (Caucasians and Japanese) are nearly identical, as are profiles for three different age groups. Age curves are presented for factor scores and for four specific cognitive tests. The younger respondents on the age curves are biological offspring of older respondents represented on the same curves, facilitating an unusual control for between-family variance. When the data were stratified by ethnicity, differential rates of cognitive development were indicated.

Adolescent↗