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Biomedical subjects

C Cohen

Publications and source records attributed to C Cohen.

At least 307 records · Page 17Linked to original sources
PubMed1985

Chlamydial pneumonitis induced in newborn guinea pigs.

One- to three-day-old guinea pigs were inoculated intranasally with the chlamydial agent of guinea pig inclusion conjunctivitis. Physical signs of infection included a marked increase in respiration rate on days 5 to 10 of infection and radiographic evidence of pneumonia on day 6. When animals were killed at various times after infection and lung tissue was examined by histopathology, evidence of pneumonia was found beginning on day 4 and lasting as long as day 12, with maximal pathological changes on days 6 to 8. The pneumonia was generally unilateral and consisted of an acute inflammatory component in the bronchioles with granulocytes in both the lumen and the wall of the bronchioles and an interstitial and intra-alveolar mononuclear infiltrate in the parenchyma of the lung. Chlamydial antigen was detected in the bronchial epithelial cells by immunoperoxidase staining, and the guinea pig inclusion conjunctivitis organism was isolated from lung tissue on days 6 to 9. No other significant bacteria were isolated from lung tissue or seen on gram stains of lung sections. Both immunoglobulin M and immunoglobulin G serum antibodies to the guinea pig inclusion conjunctivitis agent were detected as early as day 8 and reached peak levels on day 12. The infection was apparently self-limiting. This model presents the opportunity to investigate pathophysiological and immunological aspects of chlamydial respiratory infections in a neonatal animal.

Animals↗
PubMed1985

Early loss of postextrasystolic potentiation in acutely ischemic myocardium: evaluation by contrast two-dimensional echocardiography.

Studies in animals with acutely ischemic hearts have suggested that postextrasystolic potentiation (PESP) may predict the viability of dysfunctional myocardium. Most of these data have been obtained with sonomicrometers and therefore the presence and extent of PESP throughout the entire region at risk has not been defined. In this study we used contrast two-dimensional echocardiography (2DE) to define region at risk in vivo, and then with quantitative 2DE we examined the proportion of the region at risk that demonstrated PESP, the degree of the potentiation, and the time course of this response. The region at risk was divided into a central (inner 50%) and two peripheral (25% each) ischemic zones. Adjacent contrast-enhanced myocardium was divided into near and far border zones that were equal in size to the adjacent peripheral ischemic zone. Systolic thickening was analyzed within each zone along multiple radii at 5, 30, and 120 min after coronary occlusion. PESP was absent in the central ischemic zone at all three times. In the peripheral ischemic zone at 5 min, a small amount of PESP was detected (-4.1% vs + 3.1% for nonpotentiated and potentiated thickening, respectively; p less than .01). At 30 min after occlusion, no potentiation was seen in the region at risk and PESP was confined to the contrast-enhanced near and far border zones. These findings persisted at 120 min. These data indicate that the response to PESP is localized to perfused myocardium by 30 min after acute occlusion. PESP is therefore of limited value in predicting the presence of ischemic, potentially viable myocardium early in the course of acute infarction.

Animals↗
PubMed1985

The independent effects of oxygen radical scavengers on canine infarct size. Reduction by superoxide dismutase but not catalase.

Previous studies demonstrated a significant reduction of ultimate infarct size in the canine heart by the combined administration of superoxide dismutase plus catalase. This study was performed to assess the independent effects of each enzyme on ultimate infarct size due to ischemia/reperfusion. Dogs received 2-hour infusions of superoxide dismutase, catalase, or albumin (controls) via the left atrium beginning 15 minutes before and ending 15 minutes after a 90-minute occlusion of the left circumflex coronary artery. The dogs were killed 6 hours after reperfusion. After histochemical staining, infarct and risk area masses were calculated by gravimetric and planimetric analysis. Infarct size expressed as a percentage of the area at risk was: superoxide dismutase, 19 +/- 5; catalase, 30 +/- 5; and controls, 40 +/- 3. Infarct size in the superoxide dismutase group, but not the catalase group, was significantly less than in controls (P less than 0.05). No significant differences in hemodynamics or area at risk were observed that could explain the differences in infarct size. The results indicate that superoxide dismutase alone protects reperfused ischemic myocardium as well as does the combination of superoxide dismutase and catalase. The beneficial effect of superoxide dismutase and insignificant effect of catalase suggest that tissue damage during ischemia and reperfusion may be mediated largely by superoxide anion but not by hydrogen peroxide.

Animals↗
PubMed1985

The solitary pulmonary nodule. Decision analysis.

The management of a patient with a solitary pulmonary nodule is often problematic. Particularly in older patients and those with cardiorespiratory disease, the risks of intervention frequently equal or exceed its potential benefits. In this paper the choice between expectant management, thoracotomy, and transthoracic needle biopsy is examined for the asymptomatic patient with a solitary pulmonary nodule. We have designed and implemented a computer-assisted decision-analytic model of this clinical situation. The model incorporates age, sex, smoking history, and underlying cardiorespiratory status. It considers the probability of having a malignant nodule, the risks of biopsy and surgery, the sensitivity and specificity of biopsy, the resectability rate of malignant nodules, and the morbidity-adjusted life expectancies of patients in 16 outcome categories. Sensitivity analyses were performed and decision thresholds determined to assess the effect of varying the model's data base. These results can be of assistance in choosing therapy for patients with solitary pulmonary nodules and can provide a better understanding of the factors involved in this decision making process.

Aged↗
PubMed1985

Diagnosing affective disorder in adolescents: the use of the Schedule for Affective Disorders and Schizophrenia.

The Schedule for Affective Disorders and Schizophrenia was administered to 42 consecutively hospitalized psychiatrically disturbed adolescents. The SADS proved to be a good measure of current affective disorder and also identified a large number of adolescents with a positive past history of affective disorder. These patients had not been so identified by traditional assessment means. The use of a semi-structured interview is to be encouraged in the assessment period of psychiatrically disturbed adolescents and in further research at attempts to define the parameters of depressive disorders occurring in adolescents.

Adolescent↗
PubMed1985

Augmentative communication: a perspective for pediatricians.

This article has described the rationale and methods available for treatment of severely communicatively impaired children. The primary goal of such intervention is to facilitate communication, rather than speech per se, as the most realistic goal for some youngsters. To the extent that augmentative techniques affect speech development, however, they have been shown to exert a facilitory, rather than inhibitory, effect. The relatively new phenomenon of aided augmentative communication for non-speaking youngsters is still in its infancy. Service professionals in the medical, clinical, and research fields must continue to discern ways to practically apply these instruments to the task of human communication interchange.

Audiovisual Aids↗
PubMed1985

Measurement of antigen-specific IgE in nasal secretions of patients with perennial rhinitis.

Sixteen of 53 patients with rhinitis had positive skin tests corresponding with serum-specific IgE (RAST). Concomitant positive nasal secretion (NS) RAST was found in 10/16. Four patients with both negative skin tests and serum RAST had positive NS RAST. In a subset of patients with perennial rhinitis, specific IgE may be detected only in NS. Further studies are necessary to document the clinical relevance of such NS IgE antibodies.

Absorption↗
PubMed1985

The immunological basis of nasal polyp formation.

Forty-six patients were studied to assess the role of immunological factors in the formation of nasal polyps. Total IgE levels did not correlate with positive skin testing and were generally higher in polyp sac fluid than in corresponding sera. Asthmatics had significantly higher IgE levels in both serum and polyp fluid than nonasthmatics. Specific IgE (RAST) found in polyp specimens could not be detected by conventional skin or serum testing in nine of 15 patients. By direct immunofluorescence IgE was present in 81% of polyp specimens compared with 13% in mucosal controls. These data indicate that nasal polyp formation may be an IgE mediated disease process and conventional skin or serum testing may not detect this local allergic process.

Adult↗
PubMed1984

Immunohistochemical ferritin in testicular seminoma.

Immunohistochemical ferritin was demonstrated in all 23 (100%) testicular seminomas studied with antisera to liver ferritin (largely of basic isoferritins) and to myocardial ferritin (containing more acidic isoferritins). With liver ferritin antibody immuno-stain was strong in 74% with a diffuse distribution in 41%. The remaining six tumors showed moderate immuno-stain, of diffuse distribution in two. The myocardial ferritin antibody showed the following: strong immuno-stain in 52%, 58% of diffuse distribution; and moderate immuno-stain in 30%, 86% of focal distribution. Although ferritin is widespread in nature, the facts that both basic and acidic isoferritins are present in the majority of testicular seminomas, and that serum ferritin levels are reported to be increased in over 80% of patients with seminoma suggest that the demonstration of raised serum ferritin levels in the face of negative or low serum assays for human chorionic gonadotrophin and alpha-fetoprotein possibly may prove to be useful in the diagnosis, and evaluation of extent and recurrence of testicular seminomas.

Chorionic Gonadotropin↗
PubMed1984

Dissociation between two-dimensional echocardiographic left ventricular wall motion and myocardial salvage in early experimental acute myocardial infarction in dogs.

This study was designed to evaluate whether the effects of coronary reperfusion with or without a pharmacologic agent could be detected in the early hours after infarction by 2-dimensional (2-D) echocardiography applied in a manner analogous to its clinical use. Proximal left anterior descending coronary occlusion was performed in 24 dogs, and the dogs were then randomized into 3 groups. In group 1 (n = 8), coronary occlusion was maintained for 6 hours; in group 2 (n = 8), coronary occlusion was maintained for 2 hours and was followed by 4 hours of reperfusion; in group 3 (n = 8), 2 hours of coronary occlusion were followed by 4 hours of reperfusion but methylprednisolone (30 mg/kg intravenously) was also administered 15 minutes after coronary occlusion. At 6 hours, 2-D images were obtained through the closed chest wall and the percentage of the left ventricular wall motion abnormalities was determined at 4 short-axis levels. The mass at risk was defined by in vivo Monastral blue injection and infarction by triphenyltetrazolium chloride staining. The mass of necrosis was 74 +/- 4% (mean +/- standard error of the mean) of the mass at risk in group 1 and was smaller in groups 2 and 3, 44 +/- 6% and 35 +/- 4%, respectively (p less than 0.01). Percent necrosis of the left ventricle was 22 +/- 3% in group 1, 15 +/- 3% in group 2 (difference not significant) and 10 +/- 2% in group 3 (p less than 0.05 vs group 1).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Immunohistochemical ferritin in hepatocellular carcinoma.

Serum ferritin concentrations are elevated in 35% to 100% of patients with hepatocellular carcinoma (HCC). With an immunoperoxidase technique, ferritin was demonstrated in tumor tissue from 32 of 74 (43%) black southern African patients, and from 12 of 19 (63%) American patients with HCC (P greater than 0.1). Ferritin was present in nonneoplastic liver in 82% of African and 100% of American patients (P greater than 0.1). Moderate to large amounts of stainable hepatic storage iron (hemosiderin) were present in 76% of African and 67% of American patients (P greater than 0.1). Fifty-two (70%) African patients had macronodular cirrhosis. In the literature, 80% to 90% of American patients with HCC have cirrhosis. High serum ferritin levels in patients with HCC may be due to ferritin production by the tumor, or related to the associated iron overload and/or cirrhosis.

Adult↗
PubMed1984

Impaired motor timing control in specific reading retardation.

The temporal organizations of unimanual and coordinated bimanual finger tapping was compared between adolescent normal and retarded readers of above average intelligence. The same subjects were examined for speech articulation during the timed repetition of single syllables and syllable sequences. Retarded readers had substantially greater difficulty on tasks of interlimb coordination than on unimanual tapping and substantially greater difficulty rapidly sequencing syllable strings than repeating single syllables. An experimental manipulation of movement speed for both tasks indicated that the threshold at which movement speed degrades timing precision for coordinated action best characterizes the motor impairment of retarded readers.

Adolescent↗
PubMed1984

Evaluation of commercial immunoperoxidase kits in diagnosis of prostate carcinoma.

Comparison of one commercial immunoperoxidase kit for prostate specific acid phosphatase (PSAP) and two for prostate specific antigen (PA) with an unlabelled antibody peroxidase-antiperoxidase (PAP) technique using rabbit antihuman PSAP revealed generally good reproducibility of results on formalin-fixed, paraffin-embedded sections of primary and metastatic prostatic carcinoma. Frequency of positivity was 92 per cent with both our noncommercial PAP and the kit method for PSAP, and 82 per cent and 89 per cent with kits for PA. Thus, sensitivity with the PA kits was less than with our noncommercial PAP and the kit PSAP, with less intense immunostain and occasional false negatives. Specificity was good with all three kits, and no false positive results were obtained. Commercial immunoperoxidase kits provide a relatively easy and inexpensive means for practicing pathologists in a service-oriented setting to make more precise diagnoses in cases of poorly differentiated or metastatic carcinoma of prostatic origin.

Acid Phosphatase↗