Search PubMed⌕ Search

Biomedical subjects

R Long

Publications and source records attributed to R Long.

At least 37 records · Page 2Linked to original sources
PubMed1990

Antituberculous drug resistance in central Haiti.

To determine the prevalence of antituberculous drug resistance in Haiti, we conducted a 1-yr survey in a central district. From a bacillary positive (smear and/or culture positive) case rate of 80/100,000, there were 282 patients from whom Mycobacterium tuberculosis was cultured. Each isolate was packaged and delivered to Canada where speciation and drug susceptibility testing were performed. Reported resistances are those using the proportions method (Laboratory Center for Disease Control, Ottawa, Canada). Resistance to one or more drugs was found in 22% of isolates. Age was the most important predictor of resistance in Haiti; resistance rates for age groups less than 14, 14 to 29, 30 to 44, greater than or equal to 45 were 8, 19, 22, and 31%, respectively. In patients not known to have received antituberculous drugs in the past, resistances were isoniazid (19%), streptomycin (5%), ethambutol (2%), ethionamide (2%), rifampin (1%). We conclude that antituberculous drug resistance is prevalent in Haiti, especially in older age groups, and that in persons with no known antituberculous drug use in the past, resistance to isoniazid is significant.

Adolescent↗
PubMed1990

[Studies on immunoregulation and hypersensitivity of secretary otitis media].

Sixty patients with secretary otitis media (SOM) and 50 control cases were studied for their cellular immunity and hypersensitivity. Most of patients revealed that total T or T cell subpopulations were below those of the control. Eighty percent of patients had high serum IgE level and 81.2% as Positive in intradermal skin tests on inhalant allergy, but only 51.7% of patients had clinical symptoms of allergy. It was found immunologically that SOM occurred more frequently in allergic patients and most of them had abnormality of immunoregulation, and that there was a subclinical allergy for some of the patients. Allergy might play a significant role in the etiology of this disease. Authors suggest that it is necessary for patients with SOM to have some tests and treatment of immunology.

Adolescent↗
PubMed1989

The relation of flow cytometry to clinical and biologic characteristics in women with node negative primary breast cancer.

Flow cytometry (FC) analysis including DNA index (ploidy status) and cell kinetics (%S and %S + G2/M) was done on frozen tissue of the primary lesions of 101 women with node negative (N-) breast cancer who were studied prospectively. Currently, 19% (19/101) of the patients have recurred. No significant relations have been found between recurrence or survival and age, estrogen/progesterone receptor status, tumor size, and tumor type. The DNA index (ploidy) was not related to any clinical variable, time to recurrence, or survival. Aneuploid tumors did, however, have significantly higher %S phase activity. Patients with %S activity less than or equal to the median value were significantly different from those patients with %S above the median. They were older and had a higher frequency of ER/PR positive and well- or moderately differentiated tumors. Patients with %S + G2/M greater than the median value showed shorter time to recurrence (P = .055) and shorter survival (P = .006), whereas %S alone was significantly associated only with survival. Multivariate analysis showed that neither DNA index nor cell kinetics was significantly associated with time to relapse. DNA index was not significantly associated with survival; %S was of borderline significance whereas %S + %G2/M was a significant independent predictor of survival. Although FC data may provide independent information related to survival in N-women, additional research in a larger number of patients is needed to define its precise role in patient management.

Breast Neoplasms↗
PubMed1989

Chronicity. Adjustment differences of Vietnam combat veterans differing in rates of psychiatric hospitalization.

The study focuses on the frequency of inpatient care for patients with Posttraumatic Stress Disorder (PTSD). This factor, termed "chronicity," is, perhaps surprisingly, largely overlooked in many PTSD studies. The significance of chronicity was addressed through administration of Minnesota Multiphasic Personality Inventory (MMPI) to Vietnam Theater and Era veterans in an inpatient psychiatry service. MMPI scores were analyzed for two main effects: combat exposure and chronicity (i.e., number of inpatient psychiatry admissions). The results replicated research showing combat exposure is associated with greater maladjustment (i.e., higher MMPI scores). Moreover, chronicity also emerged as a significantly important variable: of all groups compared, Vietnam combat veterans higher in chronicity scored higher on MMPI clinical scales, particularly on scales Paranoia, Psychasthenia, and Schizophrenia, thereby (a) empirically establishing (a) the methodological point that number of admissions must be controlled and (b) the substantive point that chronicity is important in studies of PTSD.

Adaptation, Psychological↗
PubMed1989

Tuberculous pericarditis: long-term outcome in patients who received medical therapy alone.

A conservative approach to operative intervention in the treatment of active tuberculous pericarditis was adopted and only 4 of 16 consecutive patients underwent pericardiectomy, all within 2 months of diagnosis. One patient died of constrictive pericarditis despite pericardiectomy, and one died of acute bronchopneumonia after 8 months of otherwise successful medical management. All 14 long-term survivors were reevaluated to exclude chronic constrictive pericarditis and other potential sequelae of tuberculous pericarditis. Reevaluation included physical examination, chest radiograph, electrocardiogram, M-mode and two-dimensional echocardiogram, computed tomography (CT) scan, and in patients less than or equal to 75 years of age, incremental cycle exercise to maximum oxygen consumption. None were found to have chronic constrictive pericarditis or convincing evidence of other recognized complications of tuberculous pericarditis. Our results suggest that when pericardiectomy is not required for the relief of cardiac compression during the acute phase of tuberculous pericarditis and patients are treated with medical therapy alone, an excellent long-term outcome may be anticipated.

Adrenal Cortex Hormones↗
PubMed1989

Serotypes of Pseudomonas aeruginosa from human and animal sources.

Forty human isolates and twenty-eight animal isolates of Pseudomonas aeruginosa from Prince Edward Island area (Atlantic Canada) were serotyped using a kit consisting of 4 polyvalent O-group antisera and 17 monovalent O-type (serovar) antisera, in accordance with the International Antigenic Typing Scheme. The results showed a difference between humans/dogs (50%/48% group I) and pigs (71% group IV). Whereas O-serovar 9 and 1 appeared to be most involved in human and canine infections, O-serovar 3 was the predominant type in porcine infections.

Animals↗
PubMed1989

[Research on the etiology of nasal polyps].

One hundred and seventy patients with nasal polyps were studied. According to the history, skin tests with inhalant allergens, determination of serum nasal secretion and polyp fluid IgE, and X-ray films of nasal sinuses, it was suggested that 93.5% of them might have complicated with allergic diseases, 87.7% with sinusitis. A relationship between local IgE production and the eosinophil infiltration of polyps existed. This study suggests that allergic process acting locally on the mucous membrane of the nose is the etiologic factor and bacterial allergy probably contributes to the development of nasal polyps. In order to prevent the recurrence after polypectomy, antiallergic management combined with antibiotics and drainage of infected sinuses may be necessary in most cases.

Adolescent↗
PubMed1988

Anatomical analysis of frontal cortex sites at which carbachol induces motor seizures in the rat.

High amplitude spiking representative of seizures, accompanied by an unusual motor behavior pattern of rearing and forelimbic clonus resembling "boxing," was elicited by microinjection of the cholinergic agonist, carbachol, 4 micrograms, into the medial prefrontal cortex of the rat. A rating scale devised to score the behavior revealed a motor pattern elicited by carbachol from the medial anterior cortex which was similar to that described by Racine for electrical stimulation of the amygdala. Topographical analysis of the areas surrounding the medial anterior cortex region revealed that the motor manifestations of seizures were elicited over a wide region of the anterior cortex, with scores significantly lower at carbachol microinjection sites greater than 1 mm rostral, 2 and 3 mm caudal, and 2 mm lateral to the standard medial prefrontal cortex site. Unilateral microinjection of carbachol yielded motor seizures primarily from the contralateral forepaw, suggesting involvement of a crossed pathway. Retrograde tracing with fast blue dye, combined with immunostaining for choline acetyltransferase and NADPH-diaphorase, found that the cholinergic neurons innervating the standard microinjection site were the dorsolateral tegmental cells, as previously reported, which have been shown to also contain substance P and corticotropin releasing factor. In addition, cholinergic neurons of the nucleus basalis of Meynert region were found to innervate the standard microinjection site. These findings implicate cholinergic innervation of the rostral cortex in classical limbic seizures.

Animals↗
PubMed1988

Treatment of canine aspiration pneumonitis: fluid volume reduction vs. fluid volume expansion.

The aspiration of gastric acid causes pulmonary edema and hypoxemia. One approach to the management of this syndrome is to raise cardiac output (Qt) and O2 delivery (QO2) to ensure tissue oxygenation (VO2) at the risk of increasing the edema. Another approach reduces the edema by reducing pulmonary microvascular pressure (Pmv) at the risk of reducing QO2 and VO2. We compared these approaches in 24 anesthetized, ventilated dogs with pulmonary wedge pressure (Ppw), a clinical approximation of Pmv, of 12.5 mmHg. Before and again 1 h after endobronchial instillation of 0.1 N HCl, we measured Qt, QO2, VO2, venous admixture, and in vivo extravascular lung liquid. The dogs were then randomly divided into four equal groups: 1) 12.5 mmHg Ppw, high Qt; 2) 7.5 mmHg Ppw, intermediate Qt; 3) 4.5 mmHg Ppw, low Qt; and 4) 4.5 mmHg Ppw plus dopamine, intermediate Qt. Measured values were followed for 4 more h, after which the lungs were excised to compare wet weight-to-body weight ratios (W/B). When plasmapheresis reduced Ppw at 1 h, edema did not increase further and W/B of groups 2 (21 +/- 3), 3 (18 +/- 3), and 4 (22 +/- 3) were significantly less than in group 1 (27 +/- 3) (P less than 0.001). Although Qt decreased with Ppw, increased hematocrit and reduced venous admixture maintained QO2 in group 2 but not in group 3. In group 4 an intermediate Qt maintained QO2 even at 4.5 mmHg Ppw but edema increased to the group 2 level presumably because Pmv rose with Qt on dopamine. VO2 remained constant over time in each group. These data demonstrate that canine HCl-induced pulmonary edema, measured in vivo or gravimetrically, is very sensitive to reductions in Pmv. Moreover, the lowest Pmv (and QO2) was well tolerated because an O2 supply dependency of VO2 was not observed.

Animals↗
PubMed1986

Artificial ventilation of a canine model of bronchopleural fistula.

The authors studied the abnormalities of gas exchange and lung mechanics in a canine model of bronchopleural fistula during intermittent positive pressure ventilation (IPPV) and high-frequency oscillatory ventilation (HFOV). The left lower lobe bronchus was opened to atmosphere and it was determined that end expired volume was best maintained at frequencies of 45-50 breaths/min. during IPPV. Comparing alternating periods of IPPV and HFOV in six dogs (Group I) at matched airway opening pressure (Pao), we found that Pao2 decreased significantly to 68 +/- 14 mmHg and 69 +/- 24 mmHg, respectively, on opening the fistula. In a second group of six dogs (Group 2), when Pao was increased by additional bias flow into the ventilatory circuit during both IPPV and HFOV, Pao2 increased significantly to 89 +/- 12 mmHg and 87 +/- 8 mmHg, respectively. Repeating Group 2 studies after induction of oleic acid low-pressure pulmonary edema demonstrated that conventional IPPV was associated with large intrapulmonary shunts. HFOV, however, maintained gas exchange at near baseline values. For both Group 1 and Group 2, the calculated gas flow through the fistula was significantly less at all levels of airway pressure during HFOV. The authors conclude that HFOV offers advantages over conventional IPPV in the maintenance of oxygenation and in the reduction of gas leak through the fistula.

Animals↗
PubMed1979

After the Act.

Explore the source record for details and available documents.

Community Health Nursing↗
PubMed1979

Renin-angiotensin system in phlorhizin compared with alloxan diabetes in the rat.

In alloxan-treated diabetic rats, plasma renin activity (PRA) is decreased. One possible mechanism that may explain the decreased PRA is an increased delivery of sodium to the macula densa produced by the glucose osmotic diuresis, resulting in decreased renin release. To evaluate this possible mechanism, rats with phlorhizin diabetes, which produces a glucose osmotic diuresis without hyperglycemia, were studied and compared with rats with alloxan-induced diabetes. Whereas phlorhizin-treated rats had low blood glucose and alloxan-treated rats had elevated glucose, the glucose osmotic diuresis was similar in the two groups. PRA and plasma renin concentration (PRC) were significantly increased in the phlorhizin group. In the alloxan group, PRA was decreased and angiotensin II sensitivity increased, both significantly. Plasma renin substrate (PRS) remained adequate in each group. These results suggest that the decreased PRA in alloxan-induced diabetes is due neither to factors associated with the glucose osmotic diuresis including changes in renal tubular sodium not to decreased PRS.

Alloxan↗
PubMed1978

Use and abuse.

Explore the source record for details and available documents.

Humans↗
PubMed1978

Steroid priming of the luteinizing hormone response to luteinizing hormone releasing hormone.

Perifusion experiments were performed to study the stimulatory effects of luteinizing hormone releasing hormone (LH-RH) on the release of LH from anterior pituitary tissue. Exposure of pituitary tissue from normal male rats to LH-RH (5 ng/ml for 5 min) induced a small release of LH; in tissue from ovariectomized rats receiving no pretreatment, the release was more than three times greater and in tissue from gonadectomized male or female rats pretreated with oestradiol benzoate and progesterone, the release was six times greater than that observed in normal rats. Further exposure of pituitary tissue from gonadectomized steroid-pretreated male and female rats to LH-RH (5 ng/ml) induced an increase in the level of LH even greater than that seen after the initial exposure (priming action of LH-RH); in tissue from ovariectomized rats receiving no pretreatment, less LH was released than after the first exposure to LH-RH and in tissue from normal male rats the response was unchanged.

Animals↗