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Biomedical subjects

R J Fernandez

Publications and source records attributed to R J Fernandez.

At least 19 recordsLinked to original sources
PubMed1996

Preoperative MR imaging in hyperparathyroidism: results and factors affecting parathyroid detection.

OBJECTIVE: To determine the sensitivity of MR imaging for the detection of abnormal parathyroid glands in patients with biochemical evidence of hyperparathyroidism and to identify the factors affecting detection. SUBJECTS AND METHODS: Between 1985, 82 patients with biochemical proof of hyperparathyroidism were referred for MR imaging of the parathyroid glands prior to surgery. Axial T1- (600/20 [TR/TE]) and T2-weighted (2500/40, 80) spin-echo images were obtained using an anterior neck surface coil. The interpretation of the MR image was compared with the findings at surgery and also correlated with gland histology, volume, and weight. Cases in which a false-positive or false-negative diagnosis was made were reviewed to determine the factors affecting detection. RESULTS: MR imaging detected 71 of 92 (77%) surgically proven abnormal glands (sensitivity, 77%; 95% confidence interval (CI), 68-86%) and misdiagnosed five (1.6%) of 314 normal glands as abnormal. There was no difference in the detection of enlarged glands in patients presenting for the first time (n = 71) (sensitivity, 77%; 95% CI, 66-86%) compared with patients with recurrent hyperparathyroidism (n = 12) (sensitivity, 77%; 95% CI, 46-95%). There was no significant difference in the detection of adenomas (sensitivity, 77%; 95% CI, 65-86%) compared with hyperplasia (sensitivity, 71%; 95% CI, 42-92%). Of five patients with ectopic parathyroid glands (1.6%), four had had previous surgery. All five glands were successfully located (three mediastinal, two in the neck). Factors contributing to a false-negative MR imaging diagnosis included small gland size and thyroid disease. Four of five false-positive diagnoses were due to enlarged lymph nodes being mistaken for parathyroid glands. CONCLUSIONS: MR imaging is an accurate technique for investigation of hyperparathyroidism. Pitfalls include low sensitivity for the identification of small glands, misinterpretation of enlarged lymph nodes as parathyroid adenomas, and misinterpretation because of thyroid disease. MR imaging is particularly useful in the investigation of patients who remain hypercalcemic following initial surgery.

Adult↗
PubMed1994

Clostridium septicum gas gangrene of the gluteus maximus and an ascending colon malignant tumor. A case report.

Clostridial myonecrosis is a complication associated with contaminated traumatized wounds. Presented is the case of an elderly female with pain in her right hip, radiographic evidence of gas in the soft tissues, and no history of trauma. Evaluation of this patient revealed Clostridial myonecrosis. Culture results identified the organism as Clostridium septicum. Due to the association between Clostridium septicum and occult malignancies, colonoscopic evaluation was performed. A colonic lesion was discovered, biopsied, resected, and staged, using the Modified Duke Classification, as a well differentiated adenocarcinoma, C2 lesion. Myonecrosis and its associated malignancies carry high morbidity and mortality, but early diagnosis, appropriate treatment, and awareness of the association with occult malignancies may avert unnecessary mortality.

Adenocarcinoma↗
PubMed1990

Rosoxacin in the treatment of uncomplicated acute gonococcal urethritis.

A total of 112 male patients presenting with acute gonococcal urethritis were admitted to the hospital. The diagnosis was confirmed by smear, culture, oxidase reaction and sugar fermentation tests. The patients were treated with a single 300 mg capsule of rosoxacin. All patients except one showed adequate response to rosoxacin.

4-Quinolones↗
PubMed1990

Clinical and mycological spectrum of cutaneous candidiasis in Bombay.

A total of 150 patients with cutaneous candidiasis were studied. A detailed clinical history was taken. Scrapings were examined in 10% KOH, and the material cultured on Sabouraud's agar. Species were identified by the serum germ tube test, sugar fermentation and sugar assimilation tests. Of 150 patients 79 were females. The commonest presentation was intertrigo (75), vulvovaginitis (19) and paronychia (17). A history of chronic exposure to water was obtained in 94 cases, all had erosio interdigitalis blastomycetica and/or paronychia. Diabetes melltius as a predisposing factor was observed in 22 patients. The 10 cases of balanoposthitis had associated diabetes mellitus. Smear and culture were positive in all the patients. C. albicans was isolated in 136 cases, C. tropicalis in 12, and C. guillermondi in 2. The cultures of C. albicans had positive serum germ tube test. The 6 patients in the paediatric age group having perianal/genital involvement had a stools culture positive for C. albicans.

Adult↗
PubMed1986

Normal fibroblast mitochondrial malic enzyme activity in Friedreich's ataxia.

Mitochondrial and cytoplasmic malic isoenzymes were assayed fluorometrically in digitonin-fractionated fibroblasts from three patients with Friedreich's ataxia (FA). Normal activity was found, failing to verify an earlier report of reduced fibroblast mitochondrial malic enzyme activity in FA. The previously reported disturbance in fibroblast mitochondrial malic enzyme may be an epiphenomenon in patients with the FA phenotype. Further studies are necessary to define the primary genetic defect in this inherited disorder.

Fibroblasts↗
PubMed1981

Airway responses to antigen challenge in allergic rhinitis and allergic asthma.

The density dependence of the maximum expiratory flow-volume curve, functional residual capacity (FRC), and specific airway conductance (SGaw) were determined before and during bronchial provocation with ragweed extract in 27 subjects with ragweed hypersensitivity and a history of either bronchial asthma (16 subjects) or allergic rhinitis (11 subjects). Mean baseline SGaw was significantly lower while mean volume of isoflow (Visov) and FrC were significantly higher in subjects with bronchial asthma. During antigen challenge, 10 of 16 subjects with bronchial asthma (63%) and five of 11 subjects with allergic rhinitis (45%) showed a greater than 35% decrease in SGaw ("reactors"): mean relative decreases in SGaw from baseline were 46% and 53%, respectively. The remaining subjects showed a less than 35% decrease in SGaw ("nonreactors") with mean relative decreases of 9% (allergic asthma) and 6% (allergic rhinitis). Mean Visov increased in all subjects with bronchial asthma and in eight of 11 subjects with allergic rhinitis. A significant increase in FRC (6%) was seen only in the "reactors" with bronchial asthma. Following antigen challenge, the beta adrenergic agonist, isoetharine, increased SGaw and decreased Visov. We conclude that in asymptomatic subjects with ragweed hypersensitivity, (1) central and peripheral airway function is more abnormal in subjects with bronchial asthma than in subjects with allergic rhinitis, (2) subjects of both groups show quantitatively and qualitatively comparable airway responses during antigen challenge with a decrease in SGaw or an increase in Visov, possibly representing increase in central and/or peripheral airflow resistance, respectively, (3) Visov may be a more sensitive indicator of airway response to antigen challenge than SGaw, and (4) the bronchodilator effects of a beta adrenergic agonist on antigen-induced bronchospasm are similar in both groups.

Adrenergic beta-Agonists↗
PubMed1980

Deposition of ragweed pollen and extract on nasal mucosa of patients with allergic rhinitis: effect on nasal airflow resistance and nasal mucus velocity.

This study was undertaken to ascertain whether nasal mucus velocity (NMV) could be altered by short-term exposure to antigen. Asymptomatic patients with a history of allergic rhinitis who had a positive cutaneous reaction to ragweed extract were investigated. The plan was to achieve approximately a fourfold elevation of nasal airflow resistance (NAR) with antigen challenge and then obtain serial measurements of NAR and NMV. NMV was not significantly altered when the antigen was introduced by nasal inhalation of (1) ragweed pollen grains, (2) nebulized ragweed extract for 10 breaths, and (3) nebulized ragweed extract for 30 min on each of 3 successive days. When ragweed extract was introduced by direct instillation of the solution into the nose, NMV fell below baseline values at either 0.5 or 1.5 hr, or at both times after administration. Persistence of impairment of mucociliary transport at a time when nasal airway constrictor response had dissipated suggested that a chemical mediator might have been responsible for the alteration of clearance. The failure to demonstrate depression of mucus transport with the inhalation studies might have been due to insensitivity of the radiopaque Teflon disk method or to a qualitatively different allergic reaction to direct instillation of antigen solution.

Adult↗
PubMed1980

Rebreathing techniques for pulmonary capillary blood flow and tissue volume.

The variability of three methods of calculating pulmonary capillary blood flow (Qc) and pulmonary tissue plus capillary blood volume (Vt) during rebreathing was assessed in normal humans by using as markers acetylene, ethyl iodide, and dimethyl ether. The methods of analysis were as follows. Method I, the timing of the disappearance curves of the soluble gases was corrected by assuming that the C18O-disappearance curve intercepted at unity at time O. Method II, it was assumed that the acetylene Qc calculated by method I was correct; ethyl iodide and dimethyl ether Vt were solved by an equation using the disappearance slopes of these gases and the acetylene Qc value, thereby avoiding dependence on extrapolated intercept values. Method III, Vt was calculated by solving for a unique value of Qc between pairs of disappearance slopes of acetylene and dimethyl ether, acetylene and ethyl iodide, and ethyl iodide and dimethyl ether. Among the three methods, method I gave the most reproducible values for Vt as determined with acetylene or dimethyl ether. Using method I, both acetylene and dimethyl ether were equally acceptable gases for measurement of Vt; acetylene was a better marker for Qc measurements.

Adult↗
PubMed1978

Mucociliary transport in allergic patients with antigen-induced bronchospasm.

Tracheal mucous velocity (TMV) and respiratory mechanics were measured in asymptomatic asthmatic patients with ragweed hypersensitivity before and after inhalation of specific antigen, and with or without cromolyn sodium pretreatment. TMV was measured radiographically, and the airway response to bronchial provocation was monitored by measurements of forced expiratory volume in one sec and specific airway conductance. TMV was significantly less (6.3 +/- 2.3 mm per min, mean +/- SD) in the 6 asymptomatic asthmatic patients than in 7 normal subjects (11.6 +/- 3.6 mm per min, mean +/- SD). In the asthmatic patients, mean TMV diminished to 72 per cent of baseline immediately after bronchial provocation when specific airway conductance was decreased to 65 per cent of baseline or less, with a further decrease in TMV to 47 per cent of baseline after one hour, at which time respiratory mechanics had returned to baseline values. Pretreatment with cromolyn sodium prevented the decrease in TMV after bronchial provocation. We concluded that in asymptomatic patients with allergic asthma, (1) baseline TMV is impaired, (2) inhalation of specific antigen causes a marked decrease in TMV independent of the degree of bronchospasm, and (3) the decrease in TMV may be related to the release of chemical mediators.

Adolescent↗
PubMed1978

Hemodynamic effects of smoking cigarettes of high and low nicotine content.

We studied the hemodynamic effects of smoking cigarettes with high and low contents of nicotine in young smokers free of coronary arterial disease. The smoking of one cigarette with a high content of nicotine produced a peak rise in cardiac output of 32 percent above baseline values, and the effect persisted for one hour. Smoking a cigarette with a low content of nicotine produced a peak rise of 13 percent above baseline values, with a duration of five minutes. The rise in cardiac output was almost entirely attributable to tachycardia, since stroke volume remained relatively constant. The smoking of a cigarette with high nicotine content also caused greater and more sustained elevation in systemic blood pressure than smoking a cigarette with low nicotine content. Thus, there was a responsiveness to the dose of nicotine in cigarettes smoked by young smokers free of coronary arterial disease.

Adolescent↗
PubMedDate not supplied

Peripheral airway function in antigen-induced bronchoconstriction.

The density dependence of the maximum expiratory flow-volume curve, functional residual capacity (FRC) and specific airway conductance (SGaw) were studied in 16 asymptomatic subjects with ragweed hypersensitivity and a history of bronchial asthma, before and during bronchial provocation with ragweed extract (dose-response curve), and following inhalation of isoetharine. In ten of these subjects (seven "reactors" and three "non-reactors"), the baseline volume of isoflow (VisoV) was found to be greater than 20% of forced vital capacity. During antigen challenge, VisoV increased in all subjects; ten of these showed a greater than 35% decrease in SGaw (mean 45%) while the remaining six showed a decrease in SGaw of less than 20% (mean 9%), suggesting central and peripheral airway constriction in the former ("reactors") and primarily peripheral airway constriction in the latter ("non-reactors"). The beta-adrenergic agonist isoetharine increased SGaw and decreased VisoV, suggesting dilation of both central and peripheral airways. We conclude that in asymptomatic subjects with asthma and ragweed hypersensitivity a) peripheral airway dysfunction is frequently present, b) during antigen challenge VisoV may be a more sensitive indicator of airway response than SGaw, and c) the beta-adrenergic agonist isoetharine exhibits its bronchodilator effect in both central and peripheral airways following antigen challenge.

Adult↗