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Biomedical subjects

R M Rogers

Publications and source records attributed to R M Rogers.

At least 91 records · Page 5Linked to original sources
PubMed1982

Leydig cell hypogenesis: a rare cause of male pseudohermaphroditism and a pathological model for the understanding of normal sexual differentiation.

We describe a patient who presented for treatment of primary amenorrhea and was found to have male pseudohermaphroditism due to Leydig cell hypogenesis. This rare disorder is characterized by ambiguous genitalia with a normal clitoris, labioscrotal folds, a urogenital sinus and inguinal or intra-abdominal testes microscopically devoid of mature Leydig cells. The diagnosis is made biochemically by the presence of low testosterone and estradiol values with elevated luteinizing hormone levels in the absence of other significant hormonal changes. The clinical and laboratory features of this disorder offer support for human developmental concepts derived from animal models.

Adult↗
PubMed1982

Office spirometry.

Explore the source record for details and available documents.

Ambulatory Care↗
PubMed1981

The detection of sleep apnea in the awake patient. The 'saw-tooth' sign.

We studied 21 subjects, 13 of whom had the sleep apnea hypersomnolence syndrome associated with upper airway obstruction during sleep (SAHS-UAO) to determine if "saw-toothing" on the flow-volume loop was significantly associated with the phenomenon of airway occlusion during sleep. A "saw-tooth" pattern was present on the flow-volume loop in 11 of 13 subjects with SAHS-UAO. The presence of saw-toothing correlated with fluttering of tissue that was visualized in the upper airway via the fiberoptic bronchoscope. The specificity of the saw-tooth pattern for SAHS-UAO was 100%. Generalized obesity may indirectly influence the presence of saw-toothing due to deposition of what appeared to be adipose tissue in the pharyngeal walls. Although the number of subjects in this study is small, saw-toothing on the flow-volume loop appears to be an important aid in the diagnosis of SAHS-UAO.

Adolescent↗
PubMed1981

Immunoreactive calcitonin in the central nervous system of the pigeon.

To determine whether calcitonin (CT) is present in avian central nervous system (CNS), as it has been recently found in the CNS of other species, we studied extracts of pigeon (Columbia livia) brain by immunochemical methods. A sensitive and specific radioimmunoassay for salmon CT was used together with gel filtration and high performance liquid chromatography (HPLC). Extracts of hypothalamus contained 31.5 +/- 9.65 ng/g wet weight as salmon CT-like immunoreactivity while extracts of midbrain and brain stem contained 17.0 +/- 5.00 and 2.85 +/- 2.1 ng/g wet weight respectively. Extracts of whole pituitary gland, other areas of the CNS and vazrious peripheral tissues were below the detection limits of our assay, but salmon CT-like immunoreactivity was present in ultimobranchial gland (UBG), thyroid gland and lung tissue extracts. On Sephadex G-50 chromatography extracts of hypothalamic, midbrain, UBG and thyroid gland gave an immunoreactive peak which co-eluted with synthetic salmon CT. However, on HPLC the material in pigeon hypothalamus, midbrain, UBG and thyroid gland eluted in an identical manner when compared to each other but the major peak was 2 ml after that of synthetic salmon CT. These results clearly show that a salmon CT-like immunoreactive molecule is present in pigeon hypothalamus and midbrain, in addition to its main locations in the UBG and thyroid gland.

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

Immunochemical characterization and distribution of calcitonin in the lizard.

Immunological and chromatographic methods were used to investigate the distribution of calcitonin (CT) in various tissues of Lacerta muralis, a common wall lizard. Salmon CT-like immunoreactivity was found in high concentration in extracts of ultimobranchial gland (UBG) and in significant amounts in lung and brain extracts, but not in other tissues (oesophagus, stomach, duodenum, liver, skin, muscle and thyroid). Serial dilution of UBG, lung and brain extracts gave parallel displacement curves to that of synthetic salmon CT (sCT), but no reactivity was found in the human CT assay. On Sephadex G-50, UBG, lung and brain extracts contained an sCT-like immunoreactive peak which co-eluted with synthetic sCT. However, on high performance liquid chromatography (HPLC) the sCT-like peak in UB, lung and brain extracts eluted 2 ml later than synthetic sCT. This paper describes the first immunochemical characterization of CT in the UBG of the lizard, demonstrates the distribution of extra-ultimobranchial CT and throws some light on the evolution of the calcitonins.

Animals↗
PubMed1980

Respiratory mechanics and timing during sleep in occlusive sleep apnea.

Six human obese subjects with the sleep apnea hypersomnolence syndrome associated with upper airway occlusion (UAO) were studied during sleep to characterize respiration. Measurements included the timing components of ventilation, pulmonary resistance, flow, and esophageal and gastric pressures before and during UAOs. During the period between UAOs, the resistance progressively increased (9.4-18.1 cmH2O/l(-1) . s, P less than 0.05) as the ventilation decreased (1.82-0.77 l/s, P less than 0.05), but without changes in esophageal pressure swings. During this period, inspiratory time-to-total cycle time decreased (0.42-0.25 s, P less than 0.05) due to expiratory phase prolongation. The apnea began after expiration and terminated on inspiration with the maximal swings in esophageal and gastric pressure near the termination. During the UAO, the respiratory cycle time decreased slightly, but the expiratory pause time was significantly shortened immediately before ventilation. We suggest that the UAO is but one aspect of this syndrome and that a decrease in central nervous system activity diminishes the respiratory drive before the onset of the UAO.

Adult↗
PubMed1980

Pulmonary alveolar proteinosis: the diagnosis by segmental lavage.

Histologic findings from segmental lavage material via the fiberoptic bronchoscope were evaluated as a means of diagnosing pulmonary alveolar proteinosis. Active cases of alveolar proteinosis yielded grossly opaque and/or milky effluents. The unique histologic findings in alveolar proteinosis included: (1) very few alveolar macrophages (2) large acellular eosinophilic bodies in a diffuse background of eosinophilic granules, and (3) periodic acid-Schiff staining of the proteinaceous material with a lack of significant alcian blue staining. Thus, the diagnosis of pulmonary alveolar proteinosis can be made by evaluation of the clinical setting and histologic findings of the effluent material from a segmental lavage.

Bronchoscopy↗
PubMed1980

Chest physical therapy. The immediate effect on oxygenation in acutely ill patients.

There is no documentation in the literature of the risk of hypoxemia after chest percussion in acutely ill adults with nonsurgical pulmonary disorders. We studied the immediate effect of postural drainage and chest percussion (PDP) on oxygenation in 22 hospitalized patients with a variety of acute, nonsurgical pulmonary disorders. Heart rate, respiratory rate, blood pressure, and arterial blood gas levels were measured at four points before, during, and after PDP. There was a significant fall in PaO2 after chest percussion in ten patients who produced no sputum or small amounts of mucoid sputum. The mean PaO2 fell 16.8 mm Hg (P < 0.05) immediately after PDP, when compared to the value obtained after postural drainage alone, and had fallen another 5.3 mm Hg (P < 0.01) 30 minutes after return to the pretreatment position. There was no significant change in PaO2 in 12 patients who produced moderate to large amounts of mucopurulent secretions. The fall in PaO2 was probably due to increased ventilation-perfusion mismatch since this fall was avoided in two patients restudied while receiving 100 percent oxygen. We concluded that all acutely ill patients receiving PDP should be carefully monitored and, if necessary, should receive increased levels of inspired oxygen to avoid hypoxemia. Our data suggest that the use of PDP in patients without sputum production is not indicated and is potentially dangerous.

Acute Disease↗
PubMed1980

Immunoreactive human calcitonin-like molecule in the nervous systems of protochordates and a cyclostome, Myxine.

A molecule very closely resembling human calcitonin immunologically and chromatographically was extracted from the nervous systems of several protochordates and a cyclostome, Myxine. The presence of human calcitonin-like molecules in the nervous systems of primitive chordates suggests that they have some function in the nervous system of these species and that the bone-regulating function of the calcitonins may have arisen much later in the vertebrates.

Animals↗