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Biomedical subjects

J E Torres

Publications and source records attributed to J E Torres.

At least 37 records · Page 2Linked to original sources
PubMed1996

Nitric oxide synthase isoforms and peripheral chemoreceptor stimulation in conscious rats.

To test the effect of nitric oxide synthase (NOS) blockade on the ventilatory responses to carotid body chemoreceptor stimulation in freely behaving animals, chronically instrumented adult Sprague-Dawley rats received increasing intravenous doses of sodium cyanide (NaCN; 0-300 micrograms kg-1) before and after i.v. administration of either 100 mg kg-1 N-nitro-L-arginine methyl ester (L-NAME), a non-specific NOS blocker, or 10 mg kg-1 S-methyl-L-thiocitrulline (SMTC), a selective neuronal NOS inhibitor. SMTC did not modify the NaCN dose-response curve. In contrast, L-NAME significantly enhanced the ventilatory responses to NaCN. Western blots of equivalent amounts of protein from carotid body tissue homogenates revealed higher levels of endothelial NOS than of neuronal NOS. We conclude that endothelial NOS provides the major source for NO within the carotid body, and exerts a down-regulatory effect upon peripheral chemoreceptor responsivity.

Animals↗
PubMed1996

Effect of nitric oxide synthase inhibition on cardiorespiratory responses in the conscious rat.

Nitric oxide synthase (NOS) blockade was used to test the cardioventilatory responses to hypercapnia and hypoxia in freely behaving animals. Chronically instrumented adult Sprague-Dawley rats were studied before and after intravenous administration of either 100 mg/kg of NG-nitro-L-arginine methyl ester (L-NAME), a nonspecific NOS blocker, or 10 mg/kg of S-methyl-L-thiocitrulline (SMTC), a selective neural NOS inhibitor. L-NAME injection induced sustained blood pressure (BP) elevation with transient tachycardia and increased minute ventilation (VE), which returned to baseline within minutes. SMTC elicited similar, although transient, BP increases; however, heart rate and VE decreased. L-NAME and SMTC did not modify overall steady-state hypercapnic responses. In control conditions, hypoxia induced early VE increases with further VE enhancements at 30 min. L-NAME increased the early VE response to 10% O2 but induced late VE reductions in hypoxia. SMTC did not change early VE responses but induced marked reductions in the later VE hypoxic responses. In control animals, hypoxia induced a significant heart rate increase. This increase was absent during the early response after SMTC and was followed in both L-NAME- and SMTC-treated animals by significant heart rate reductions to values below room air. Similarly, the sustained BP response to hypoxia in control animals was absent after administration of NOS inhibitors. These findings suggest that NOS activity exerts excitatory influences on respiration and cardiac chronotropy and sustained vasomotor tone during hypoxia. We speculate that NOS-mediated mechanisms may play an important role in hypoxia-induced ventilatory roll-off during wakefulness.

Animals↗
PubMed1996

Characterization and developmental aspects of anoxia-induced gasping in the rat.

With increasing postnatal age, mammals display diminished tolerances for prolonged exposures to severe oxygen deprivation. Similarly, duration and efficiency of gasping, a unique mechanism for enhancing survival after anoxia-induced apnea, are also affected by postnatal age. We hypothesized that maturational patterns of anoxia-induced gasping may encompass more than a single monophasic phenomenon. Each of the putative phases of the gasping response may underlie unique characteristics which could be of relevance to survival capability. To study these issues, adult rats and rat pups at 2-3, 5, 10, 15, and 25 days of age underwent anoxic exposures with 100% N2 in a barometric chamber. In pups aged < 25 days but not thereafter, following an age-dependent period of central apnea, an initial gasping phase characterized by vigorous and frequent periodic bursts of a large inspiratory effort preceded and followed by expiration excursions emerged (phase I). This phase was followed by a period of relative respiratory silence of variable duration with occasional, interspersed phase I-like gasps (phase II). Finally, a third phase easily recognized by the onset of frequent inspiratory-only gasping efforts developed (phase III). The amplitude of phase III inspiratory gasps progressively diminished until their complete cessation. Although overlap between gasping phases was present, a marked age dependency in both duration and gasping frequency within each phase occurred. We conclude that anoxia-induced gasping responses in rat pups < 25 days old are triphasic in nature, exhibit defined phase-locked periodicities and respiratory effort patterns, and undergo significant maturation.

Aging↗
PubMed1996

Longitudinal assessment of hypercapnic ventilatory drive after tracheotomy in a patient with the Prader-Willi syndrome.

The clinical course and changes in hypercapnic ventilatory drive over time were serially assessed before and after tracheostomy placement in a 14 year old, morbidly obese female patient with Prader-Willi syndrome, severe obstructive sleep apnoea, and obesity-hypoventilation syndrome. A tracheostomy became necessary after supplemental oxygen and continuous positive airway pressure (CPAP) had failed to improve the severity of nocturnal hypoventilation. Continued improvement in the slope to rebreathing hyperoxic hypercapnia occurred from 2-10 weeks after tracheotomy in conjunction with night-time bilevel pressure ventilation, and remained unchanged thereafter. In contrast, increases in mean resting minute ventilation at an end-tidal carbon dioxide tension (PET,CO2) of 8 kPa (60 mmHg) were documented even after 30 weeks. This case study illustrates the time-frame of dynamic ventilatory changes occurring after removal of upper airway resistance and normalization of nocturnal alveolar ventilation.

Adolescent↗
PubMed1995

[The current status in obtaining a license for the practice of dentistry in the European Union and the United States of America].

Present regulations on the issuance of dental licenses are very different between the United States of America and the European Community. Two different mechanisms attempt to arrive at the fairest possible solution: licenses controlled by either national and/or local examinations in the United States, and licensing by credentials in the European Community. Both are compared and discussed.

Credentialing↗
PubMed1995

Acquired nevus flammeus.

This is the case of a 55-year-old male with cirrhosis who required a LeVeen shunt for relief of refractory ascites. After eight months he developed recurrence of the ascites and a erythematous patch around the surgical scar. Skin biopsy revealed a proliferation of small and medium-sized vessels throughout the dermis. The acquired form of nevus flammeus is rare an is usually preceded by trauma. This is the report of a patient with an acquired nevus flammeus associated to an obstructed peritoneovenous shunt.

Abdomen↗
PubMed1994

Melanoma in situ on facial skin damaged by sunlight.

Solar lentigines ("liver spots") commonly occur on sun-damaged skin in the elderly population. Although they are benign, it is difficult in practice to distinguish solar letigines and junctional nevi from melanoma in situ. We report a patient who developed melanoma on the same site as a previously diagnosed solar lentigo. We also review the histopathological criteria for differentiating these benign lesions from potentially malignant ones.

Aged↗
PubMed1994

Eccrine angiomatous hamartoma.

This is the case of a 13 year-old female evaluated for a congenital skin lesion on the left buttock. Physical examination revealed a well-defined light brown patch with a 4mm papule on the center. A skin biopsy revealed an increased number of eccrine glands associated to a proliferation of vascular channels, particularly capillaries. These findings are consistent with a diagnosis of eccrine angiomatous hamartoma.

Adolescent↗
PubMed1993

Response to treatment and recurrence of dermatomycosis in patients with diabetes.

Thirteen diabetic and sixteen control patients with skin infections with dermatophytes and Candida albicans were evaluated for the response to treatment and the recurrence of the condition. Culture-proven infections of these organisms were treated with a topical antifungal cream (oxiconazole nitrate) for 30 days. There was no difference in response to treatment between the two groups. Nine diabetic and ten control patients were re-evaluated three months after finishing the treatment. Four of the nine diabetic patients (44%) and one of the ten control patients (10% had evidence of recurrence. Dermatophytic skin infections in diabetic patients seem to respond adequately to topical treatment, however, recurrences appear to be frequent.

Administration, Topical↗
PubMed1983

Colposcopically directed conization for frozen-section examination in the management of cervical intraepithelial neoplasia.

We found colposcopically directed conization for frozen-section (F/S) examination to be 100% accurate in ruling out the presence of invasive cervical carcinoma. Therefore, the definitive treatment for cervical intraepithelial neoplasia (CIN)--hysterectomy in women who do not want more children--could be performed while the patient was still under the anesthetic used during procurement of the conization specimen. This technique reduces the risk of using anesthesia a second time and also reduces the costs of CIN treatment. Colposcopically directed conization should be done by experienced colposcopists only.

Adult↗
PubMed1981

Herpes simplex virus type 2 and human cervical cancer: relationship between cellular and immune assays for the detection of previous infection.

Women with invasive carcinoma of the cervix were examined for evidence of previous infection with herpes simplex virus (HSV) type 2 (HSV-2) by three assays: Assay 1 measured the ratio of lymphocyte blastogenesis to herpes simplex virus type 1 (HSV-1) and HSV-2 antigens; assay 2 measured the ratio of antibody titer to surface antigens of HSV-1-infected and HSV-2-infected cells; assay 3 measured the titer of type-specific antibody to HSV-1 and HSV-2, including the percentage of HSV-2 type-specific to total HSV antibody. The ability of assays to detect previous infection was evaluated with the use of groups with histories of infection with HSV-1, HSV-2, or both. Women with invasive cervical cancer were matched to control women by age (+/- 3 yr), race (black), and socioeconomic class (low). All assays detected similar patterns of previous HSV-2 infection, and all indicated a higher frequency of previous HSV-2 infection in women having cervical cancer. Results from assays 1 and 2 suggest that many of the cancer patients and controls also had been infected with HSV-1. The more definitive type-specific antibody assay confirmed those results and showed that sera from 85% of women having cervical cancer and from 100% of the matched controls contained antibody type-specific for HSV-1.

Antibodies, Viral↗
PubMed1979

Association of Herpes simplex virus (HSV) with cervical cancer by lymphocyte reactivity with HSV-1 and HSV-2 antigens.

Twenty-six women with invasive cervical cancer were examined for lymphocyte responsiveness to phytohemagglutinin (PHA) herpes simplex virus (HSV). Blood specimens were obtained from each patient before radiation therapy and separated into subpopulations by Ficoll-Hypaque centrifugation. Lymphocytes were cultured in RPMI-1640 containing autologous plasma and exposed to PHA, HSV-1, HSV-2, and control antigens. The results compared with those of women having negative Papanicolaou smears and matched to the cancer patients by age, race, and socioeconomic class revealed significant differences in blastogenic response (3H-thymidine) to HSV-2 antigens. Results from groups with known HSV-1 and HSV-2 infections indicated that differences were associated with the cancer patients having a higher frequency of HSV-2 infection. Results generally agreed with the findings of previous studies in which serologic test procedures were used.

Antigens, Viral↗
PubMed1976

Colposcopy screening for cervical cancer in a family planning program.

A brief history is presented of colposcopy in the United States and at Louisiana State University. Incorporation of colposcopy screening as a part of the cervical cancer screening program in the Louisiana Family Planning Program is discussed, and the reasons for the need of "in house" colposcopy service are outlined. Data of the Louisiana Family Planning Program Colposcopy Service for the three-year period 1972 through 1974 are presented. Analysis of these data reveals that cytology when used without colposcopy fails to reveal the presence of major cervical pathology in 30.2% of patients. It is concluded that colposcopic screening must be a part of all family planning and cervical cancer detection programs.

Colposcopy↗