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Biomedical subjects

H Cohen

Publications and source records attributed to H Cohen.

At least 343 records · Page 19Linked to original sources
PubMed1991

Factor XII deficiency and pregnancy.

A 19-year-old primigravida with known factor XII deficiency (prepregnant factor XII level of 21%) presented with placental abruption and preterm labor at 26 weeks' gestation. A healthy 925-g female infant was born by spontaneous vaginal delivery. The mother had no postpartum hemorrhage or further complications, and the infant demonstrated no intracranial or other forms of hemorrhage up to 70 days of age. The infant's factor XII level was 34% (normal for her age). There are only two previous reports of factor XII deficiency in pregnancy cited in the English literature, and both were uncomplicated. In view of the risk of thromboembolic complications in nonpregnant individuals with factor XII deficiency, pregnant women with a prolonged activated partial thromboplastin time and no lupus anticoagulant or anticardiolipin antibody syndrome should also be investigated for deficiencies of factors VIII, IX, and XII. These patients should be given the appropriate counseling and should be monitored for features of thromboembolism if factor XII deficiency is confirmed.

Abruptio Placentae↗
PubMed1990

[Cordocentesis for prenatal diagnosis].

Cordocentesis for prenatal diagnosis was being performed in the seventies during the process of fetoscopy. Since then the technique has been used as a diagnostic tool for intrauterine infection, hematological and metabolic disorders and metabolic status of the fetus; and for rapid cytogenic analysis. We report our first 207 cordocenteses performed since December 1985. First puncture was successful in half the cases. The procedure resulted in termination of pregnancy in only 0.96% of cases. Though a new technique, cordocentesis is playing a major role in modern perinatology. The possibility of a direct route to fetal blood vessels early in pregnancy would lead to earlier diagnosis and treatment.

Blood Specimen Collection↗
PubMed1990

Cerebral hemispheric involvement in the acquisition of new phonetic categories.

This study was concerned with the involvement of the cerebral hemispheres in the acquisition of perceptual skill with novel speech sounds. Two groups of eight subjects rated on three occasions the dissimilarity of pairs of Mandarin Chinese speech sounds varying on voicing and aspiration, presented to the left or right ear with contralateral noise. The experimental group received listening experience with long passages of Mandarin containing the target sounds. Multidimensional scaling analysis of dissimilarity ratings indicated that listening experience leads to increased perceptual differentiation of phonetic categories drawn from a language unfamiliar to the listener. This improvement occurred sooner with presentation of the target sounds to the right hemisphere than to the left if the phonological contrast was along the voicing dimension. Improvement in the perception of stimuli varying on aspiration occurred in right ear presentations only. This finding supports the position that speech perception mechanisms at the feature level may be distributed asymmetrically across the hemispheres.

Adult↗
PubMed1990

Enhancement of the rate of the beta-elimination of phosphate from radicals derived from glycerol-2-phosphate by Cu(I)-phenanthroline. A pulse radiolysis study.

Hydroxyl radicals abstract hydrogen atoms from glycerol-2-phosphate with a specific rate constant of (7.0 +/- 1.5) x 10(8) M-1s-1 forming the beta-phospho radical as the major product. At physiological pH this radical undergoes a beta-phosphate elimination with a rate constant less than or equal to 1 x 10(3) s-1. The beta-phospho radical reacts with Cu(I)-phenanthroline to produce an unstable transient with a metal-carbon sigma-bond which has an absorbance similar to that of the cuprous phenanthroline complex in the visible region. This intermediate decomposes via a beta-elimination of phosphate with a rate constant of (1.0 +/- 1.5) x 10(4) s-1, which was independent of the acidity in the pH range 4-9.

DNA Damage↗
PubMed1990

Blood pressure reactivity predicts myocardial infarction among treated hypertensive patients.

High blood pressure (BP) defines a prognostically heterogeneous group. Because BP varies according to time, setting and means of observation, it has been postulated that BP reactivity might better predict cardiovascular disease (CVD) than does unidimensional measurements. To assess BP reactivity, the difference between pretreatment nurse (RN) and physician (MD) diastolic BP (DBP)--systematically recorded in that order--or MD-RN DBP, was obtained in 1737 previously untreated patients with sustained, RN BP greater than or equal to 160 and/or 95 mmHg. Patients stratified by tertiles of MD-RN DBP [(I) less than or equal to - 3, (II) -2 to 3 and (III) greater than or equal to 4 mmHg] were similar by sex, race, age, body mass index, cholesterol, electrocardiography, prior CVD, smoking and pretreatment or attained in-treatment BPs. During 14 years of followup, myocardial infarction (MI) incidence per 1000/year were, tertile I (3.2), II (3.7), III (7.6) (relative risk = 2.4, III vs I + II, p less than 0.05), whereas stroke incidence and non-CVD mortality were evenly distributed. By Cox survival analysis, controlling for other entry characteristics only age, sex and DBP reactivity remained predictive (p less than or equal to 0.03) of MI or total CVD. Thus, BP reactivity, probably a centrally-mediated phenomenon, identifies a subgroup of hypertensives with an increased propensity for MI despite successful BP control.

Adult↗
PubMed1990

Developmentally regulated interactions of liver nuclear factors with the rat phosphoenolpyruvate carboxykinase promoter.

A sequential pattern of interactions of trans-acting factors in rat liver with the phosphoenolpyruvate carboxykinase promoter during late development was observed. A liver-enriched factor, possibly AF1, interacted with the promoter in fetal liver, whereas a factor with the characteristics of C/EBP bound the promoter after birth with the onset of the gene expression.

Age Factors↗
PubMed1990

[Not Available].

Explore the source record for details and available documents.

History of Pharmacy↗
PubMed1990

[Endophthalmia of pseudophakic patients].

After the era of antibiotics, a real improvement has been stated in the percentage of endophthalmis following cataract surgery which has fallen from 1% between 1950 and 1977, to 0.2-0.3% now. Since 10 lenses have been implanted, the incidence of acute bacterial endophthalmitis due to pathogenic organisms has not increased. But we now encounter many cases of "cold endophthalmitis", with a lowered symptomatology, a delayed onset, and which are due to organisms of low virulence. Their prognosis can be improved by early vitrectomy combined to intraocular antibiotics in the more severe cases, and by using antibiotics of high intraocular penetration in the milder cases. We report fifteen cases of pseudophakic endophthalmitis. The clinical course was acute in one case, sub acute in eleven cases, and chronic in three cases. In the latter fourteen cases a vitrectomy was performed in 60% of the cases. Aqueous and vitreous taps have found cocci gram + in five cases. Visual results are superior to 1/20 in 2/3 of the cases.

Acute Disease↗
PubMed1990

Sex, drugs, and HIV infection in a New York City hospital outpatient population.

Persons attending outpatient clinics at Bellevue Hospital Center in Manhattan, New York City were invited to be tested for antibodies to human immunodeficiency virus (HIV). In pretest counseling, males were asked if they had injected nonprescription drugs or engaged in sex with other men since January 1, 1977; if so, they were asked not to participate and were referred elsewhere for testing. Face-to-face interviews and HIV testing were completed for 1,119 subjects with no prior indication of HIV seropositivity. Willingness to participate in the study was significantly greater among women than men and among younger than older persons. After exclusion of two subjects with indeterminate HIV serology, seroprevalence was 6.3% (70/1,117) overall, 7.1% (26/368) among men, and 5.9% (44/749) among women. HIV seropositivity among female i.v. drug users was 37% (27/74). Among heterosexuals without other HIV risk factors, estimated seroprevalences were 2.7% (25/924) overall, 3.3% (10/305) among males, and 2.4% (15/619) among females. Among heterosexual men, the data suggested associations of HIV seropositivity with sex with prostitutes and sex with numerous partners. Multiple logistic regression analysis indicated that significant predictors of HIV infection among women were a history of sexual contact with a male intravenous drug user, recent last use of intravenous drugs, and long duration of residence in New York City. Sexual intercourse with persons from AIDS risk groups was reported by 11% of men and 18% of women. The modal method of birth control reported by both men and women was "no method".

Adult↗
PubMed1989

Prevalence of Helicobacter pylori infection and histologic gastritis in asymptomatic persons.

We estimated the prevalences of Helicobacter pylori (formerly called Campylobacter pylori) infection and histologic gastritis in 113 asymptomatic persons, using endoscopic biopsy of the gastric antrum and corpus. Unsuspected lesions, mainly mucosal erosions, were revealed at endoscopy in 16 subjects (14 percent). Gastritis was found in 42 subjects (37 percent), of whom 36 (32 percent of the total) were found to be infected with H. pylori on the basis of hematoxylin-eosin staining. H. pylori was not found in any of the 71 subjects with normal histologic features. Gastritis and H. pylori were noted in both the antrum and corpus in 75 percent of those infected (n = 27). The prevalence of H. pylori infection increased from 10 percent (2 of 20 subjects) in those between the ages of 18 and 29, to 47 percent (7 of 15) in those between the ages of 60 and 69, but the effect of age did not reach statistical significance. The prevalence of gastritis increased significantly with advancing age. Stepwise logistic regression analysis revealed that the relative risk for H. pylori infection associated with recent (within six months) antibiotic use was 5.8 (95 percent confidence interval, 1.5 to 22.1), whereas the relative risk was 6.5 (95 percent confidence interval, 1.4 to 29.2) for those who had never used bismuth compounds. We conclude that histologic gastritis and H. pylori infection commonly occur in the stomach of apparently normal persons and increase in prevalence with advancing age. All the subjects with H. pylori infection had gastritis, suggesting a possible etiologic role for the bacterium in the histologic lesion.

Adolescent↗
PubMed1989

Treatment-induced blood pressure reduction and the risk of myocardial infarction.

To examine the relationship between degree of treatment-induced blood pressure (BP) reduction and myocardial infarction, the experience of 1765 previously untreated, mild to moderate hypertensives (initial BP greater than or equal to 160 and/or greater than or equal to 95 mm Hg) in a systematic treatment program was reviewed. Over an average of 4.2 years, there were 39 morbid or fatal myocardial infarctions. Three types of fall in diastolic BP (final minus pretreatment) were defined: small (less than or equal to 6 mm Hg), moderate (7 to 17 mm Hg), and large (greater than or equal to 18 mm Hg). By Cox regression, an association was observed between myocardial infarctions and both a large and a small fall, relative to a moderate decline. Age and sex were independent risk factors. Body mass index, cholesterol level, electrocardiogram, race, prior cardiovascular disease, smoking status, initial and final revisit BP, total intreatment BP, and systolic BP were not. Since both a large and small reduction in diastolic BP were associated with a higher incidence of myocardial infarction (relative to a moderate fall), perhaps a moderate reduction in diastolic BP should be the goal of treatment for mild and moderate hypertensives.

Blood Pressure↗
PubMed1989

Immunologic memory induced at birth by immunization with inactivated polio vaccine in a reduced schedule.

One hundred forty-one healthy newborns were immunized 24 hours after birth with one dose of inactivated polio vaccine (IPV) of enhanced potency. Following the administration of a second vaccine dose six months later, a considerable proportion of babies responded with neutralizing antibody (NA) to the three poliovirus types. The very rapid occurrence and high antibody titer were indicative of an anamnestic response. Twenty-one infants who still had NA less than 1:4 to one-more poliovirus types after the second vaccine dose responded with very high NA values 7-10 days after a supplementary dose of IPV. It appears that IPV of enhanced potency administered at birth is apt to induce immunologic memory, which should provide the basis for protection against paralytic poliomyelitis in case of exposure to wild poliovirus later in life.

Humans↗
PubMed1989

Hemispheric specialization for speech and non-verbal stimuli in Chinese and French Canadian subjects.

Dichotic speech (CV syllables) and non-verbal stimuli (melodies, tones and triple tones) were presented to 20 French Canadian (10 men, 10 women) and 19 Chinese (10 men, 9 women) right-handed university students to investigate cultural and sexual differences in auditory functional asymmetry. Analyses of variances on correct scores showed a REA in the perception of speech and a LEA in the perception of melodies and triple tones for both groups. Cross-cultural effects were observed for speech only, indicating a better overall performance on the part of French Canadian students. Moreover, women were better than men in the perception of tones and triple tones, suggesting that women may attend more to intonational information. Finally, the results for both ethnic groups showed the same pattern of interhemispheric functional asymmetry for speech and non-speech material.

Adult↗
PubMed1989

Right hemisphere EEG sensitivity to speech.

Recent speech perception work with normals and aphasics suggests that the right hemisphere may be more adept than the left at making the voicing discrimination, and the reverse for place of articulation. We examined this right hemisphere voicing effect with natural speech stimuli: stop consonants in pre-, mid-, and postvocalic contexts. Using a neuroelectric event-related potential paradigm, we found numerous effects indicating bilateral components reflecting the voicing and place contrast and unique right hemisphere discrimination of both voicing and place of articulation.

Adult↗