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Biomedical subjects

I Gonzalez

Publications and source records attributed to I Gonzalez.

54 records · Page 3Linked to original sources
PubMed1992

Behavioural effects in adulthood of neonatal manipulation of brain serotonin levels in normal and androgenized females.

5HT concentrations in the hypothalamus are higher in females than males over the second week of life and this differentiation is testosterone-dependent. We have investigated the possible influence of 5HT over this period on the development of systems that control adult behaviour, in particular those influenced by neonatal testosterone. Neonatal androgenization (250 micrograms/pup testosterone propionate; TP; on day 1 postpartum) induced a masculine pattern of behaviour in females ovariectomised in adulthood and bearing a TP implant. The neonatal treatment reduced exploration, motor activity and female sexual behaviour and increased anxiety, orientation toward the incentive female and male sexual behaviour. Depletion of 5HT by pCPA (100 mg/kg days 8-16 postpartum) enhanced the TP-induced increment in locomotion and female sexual behaviour and increased sexual orientation toward the incentive female, while 5HTP (20 mg/kg days 8-16 postpartum) antagonised the reduction in exploration by TP. Thus 5HT may normally exert an inhibitory control on the action of neonatal testosterone on exploration, motor activity and sexual behaviour. Neonatal PCPA treatment also had a marked anxiolytic effect which was independent of the presence of T as it was noted in normal and androgenized females and previously has been observed in intact males. This might indicate a primary control by a serotonergic system on the development of the systems controlling anxiety.

5-Hydroxytryptophan↗
PubMed1992

Role of associated bacteria in growth and toxicity of cultured benthic dinoflagellates.

Clonal cultures of the toxic benthic dinoflagellate Ostreopsis lenticularis isolated from the coastal waters of southwest of Puerto Rico show peak toxicities during the stationary phase of growth, correlated with significant increases in bacteria directly associated with these cells. The specific toxicity (MU/mg) of dinoflagellate extracts in control cultures increased 340% during the static phase of culture growth, while those cultures treated with antibiotics that inhibit prokaryote protein synthesis showed no significant increase in toxicity during this phase of culture growth. There was a significant decrease in the diversity of dinoflagellate associated bacterial strains in antibiotic treated cultures. These data indicate that associated bacteria play a role in toxin production by dinoflagellate-bacteria consortia when grown in laboratory culture.

Animals↗
PubMed1992

Major bacterial infections following liver transplantation: a prospective study.

The incidence and characteristics of major bacterial infections were studied prospectively in 50 consecutive adult patients who underwent liver transplantation (LT). All patients received the same protocol of immunosuppression, bowel decontamination, antibiotics prophylaxis, and follow-up. Thirty-two patients (64%) had at least one episode of major bacterial infection. One death was directly related to a bacterial infection, accounting for 13% of postoperative mortality. The most critical period for infection was the first 2 months after surgery, when 69% of the infections occurred. The most frequent clinical presentations were bacteremia, pneumonia and abdominal abscesses. Eighty percent of the bacteremias had an identifiable source, the most frequent being intravascular catheters. Gram-positive microorganisms (69%) predominated over gram-negative rods (26%) and anaerobes (5%). The use of selective bowel decontamination (SBD) with norfloxacin may explain this predominance. Major bacterial infections are an important source of morbidity and mortality after LT. Efforts to prevent these infections and to determine their source and specific treatment, will improve the management and the outcome of these patients in the future.

Adult↗
PubMed1990

[Heart involvement in diabetic patients].

Diabetic cardiomyopathy appears to be due to "premature ageing" of the myocardium which loses some of its compliance and becomes less sensitive to catecholamines. The condition seems to be severe mainly in those frequent cases where it is associated with hypertensive and/or ischaemic cardiomyopathy. Neuropathic denervation of the heart, usually partial and predominantly affecting the parasympathetic system, might play a part in the myocardial dysfunction. It has been held responsible for sudden death, but its real consequences in diabetic patients remain to be assessed. Coronary artery disease is the most common cardiac complication of diabetes mellitus: it accounts for 50 per cent of deaths among noninsulin-dependent, and 25 per cent among insulin-dependent diabetic subjects. Its incidence does not seem to decline and its severity, notably in women, is demonstrated by a mortality rate that is twice as high as that observed in the non-diabetic population; hence the importance of primary prevention and treatment of risk factors. However, the specificity to abnormal lipid metabolism, notably hypertriglyceridaemia, the potentiation by chronic hyperglycaemia of the harmful effects of arterial hypertension, and the possible responsibility of coagulation disorders and hyperinsulinism are points that have not yet been elucidated. We still do not know whether the objectives to be attained in terms of plasma cholesterol, triglycerides and fibrinogen levels, as well as of blood pressure values, should be different in diabetic and non-diabetic subjects. In any case, the treatment of risk factors should be accompanied by a systematic search for silent ischaemia which is 2 to 3 times more frequent among diabetic patients. Detection of silent ischaemia by electrocardiography during exercise and/or Holter recordings, and by echocardiography and/or thallium scintigraphy should be performed not only in diabetic patients with coronary artery disease but also to those with other risk factors or albuminuria.

Albuminuria↗
PubMed1990

Inhibition of HIV replication by naphthalenemonosulfonic acid derivatives and a bis naphthalenedisulfonic acid compound.

Several naphthalenemonosulfonic acid analogs and a bis naphthalenedisulfonic acid have been evaluated for anti-HIV activity in assays using H9 and MOLT-3 cells. Among the naphthalenemonosulfonic acids, a 4-amino-5-hydroxy compound and a 4,5-diamino compound showed low anti-HIV activity (upto 50% inhibition) at non-toxic doses. The bis naphthalenedisulfonic acid compound demonstrated significant suppression of HIV-1 antigen expression as measured by monoclonal antibodies to p17 (95%), p24 (94%) and syncytia inhibition (82%) at a dose of 20 micrograms/ml that was non-toxic to the host cells. The bis naphthalenedisulfonic acid analog represents a new class of compounds which may be effective in the treatment of HIV infected patients. The structure activity relationship and a probable mode of action of these compounds is discussed.

Antibodies, Monoclonal↗
PubMed1980

The surgical management of left atrial thrombosis.

A series of 122 consecutive patients with left atrial thrombosis is reviewed. Positive diagnosis was achieved in only 40 cases (36%) based on the angiographic findings and the presence of coronary fistula. The main cause of mortality and morbidity was cerebrovascular embolism. A change in our surgical technique, including the occlusion of the mitral orifice, has so far eliminated this problem.

Adult↗
PubMed1980

Erosive lichen planus and fibroxanthosarcoma (malignant fibrohistiocytoma): coincidence or association?

Severe erosive lichen planus of the skin and oral and anal mucosae coincided with retroperitoneal fibroxanthosarcoma (malignant fibrohistiocytoma) in an asthmatic patient. Clinical evolution after surgical removal of the tumor, radiotherapy, and chemotherapy was favorable, with great improvement of the lichen planus and the asthma. The exact nature of the relationship between erosive lichen planus and tumors is not known, but there is circumstantial evidence that their coexistence is not just a fortuitous coincidence.

Adult↗
PubMedDate not supplied

Assessment of diurnal tensional curve in early glaucoma damage.

We know very little about the relationship between the diurnal intraocular pressure variations and the progression of visual field loss. A prospective study of 149 eyes of 149 patients suffering from intraocular hypertension has been carried out through a minimum period of five years. At least 4 years before the appearance of field defects, we detected significant oscillations of IOP in the 64% of the cases prone to develop visual field loss. Likewise, we have found a statistically significant relationship between the presence of defects in the RNFL (retinal nerve fiber layer) and the existence of significant oscillations of IOP.

Circadian Rhythm↗
PubMedDate not supplied

HIV antibody testing and client retention in the therapeutic community. A preliminary report of Phoenix House.

This report describes the current approach to testing for the human immunodeficiency virus (HIV) antibody at Phoenix House, a large therapeutic community (TC) in the northeastern United States, and presents findings on retention of clients who have been tested for HIV antibodies and notified of their HIV serostatus. A total of 240 clients were tested while in treatment at Phoenix House between April 1988 and July 1992. Of these, 51 tested HIV positive. An additional 76 clients had tested positive for HIV antibodies prior to entering treatment. The difference in length of treatment stay between those who tested negative while in treatment and those who tested positive while at Phoenix House was not significant (t = 0.41, df = 238, p > .683). Although clients who tested seronegative during treatment were found to remain in treatment a significantly longer amount of time than the total population of seropositive clients (t = 4.54, df = 314, p < .001), those who learned of their seropositive status while in treatment remained in the program longer than clients who entered treatment aware of their seropositivity (t = 4.08, df = 125, p < .001). These findings suggest that acute reactions to the knowledge of seropositivity did not determine most premature terminations. The use of a small group, a core technical element of the TC, may have provided a favorable context for the task of HIV counseling and testing.

AIDS Serodiagnosis↗
PubMedDate not supplied

Submandibular tissue obstruction of tracheostomy tube: reversal with "chin sling".

We report on a 55-year-old woman with a tracheostomy who had unexplained respiratory failure from acute nocturnal shortness of death. During the second day of admission, the patient noticed that her "second chin" folded over the tracheostomy on neck flexion, occluding her artificial way. The patient jury-rigged a strap to retain the submental tissue from occluding the opening of the tracheostomy tube. She was subsequently free from obstructive symptoms with good oxygen saturation even with neck flexion. She was consequently discharged with a presumptive diagnosis of acute upper airway obstruction. We believe that this unusual complication of the tracheostomy tube may be more common than appreciated. Accordingly, patients with a tracheostomy should be evaluated through a full range of body and neck positions. Increases in body fat and tissue relaxation should be suspected as possible causes occlusion of tracheostomy tubes. The application of a "chin sling" can reverse this unusual upper airway obstruction until definitive correction by surgical lipectomy is performed.

Adipose Tissue↗
PubMedDate not supplied

Muscular structural changes following fadenoperation.

The authors describe the macroscopic, histological, and ultrastructural findings observed in an experimental animal model of the fadenoperation . Grossly, muscular fibrosis and musculo-scleral adhesions were well established after the second postoperative month. Histologic findings demonstrated the development of a granulomatous, foreign body reaction around the musculo-scleral fixation suture, collagenization of the muscle tissue from the first postoperative month and degenerative phenomena in the muscle fibers. Electron transmission microscopic study showed atrophy and angulation with distortion of the myofibrillar matrix, along with alteration of the Z bands of muscle fibers, mitochondrial alteration, and dilatation of the sarcotubular system. All these experimental findings suggest the relative irreversible effects of the fadenoperation after the early postoperative period and for the first time, demonstrated that this surgical technique alters the muscle structure.

Animals↗
PubMedDate not supplied

Open heart surgery for thrombosis of a prosthetic mitral valve during pregnancy. Fetal hydrocephalus.

Pregnant women with cardiac valvular prostheses present an important risk factor and the major complications are endocarditis and thromboembolism. Thromboembolism is determined by a hypercoagulation state. Compulsory anticoagulation treatment is an associated risk factor producing maternal and fetal complications. Different open heart surgical cases during pregnancy have been reported and a review of the literature shows favourable maternal prognosis. A 30-year-old woman with a Björk-Shiley mitral prosthesis, during the 6th week of pregnancy presented with thrombosis and embolism due to a change in anticoagulation treatment from acenocumarol to heparin. Open heart surgery was carried out and the patient's course was favourable. A fetal hydrocephaly of unknown etiology was discovered during the 18th week of pregnancy. Open heart surgery during pregnancy and the necessity of thromboembolic prophylaxis, have been analysed and revised.

Adult↗
PubMedDate not supplied

Angiocardiographic demonstration of a partial defect of the pericardium with herniation of the left atrium and ventricle.

A case of a patient of 44 years of age with nonspecific thoracic symptomatology and anomalous protrusion of the second arch of the left border of the cardiac silhouette is reported. Cineangiocardiography showed a herniation of the left atrium and ventricle through a partial defect in the left pericardium demonstrating a mechanism that can give rise to sudden death by cardiac incarceration. Prophylactic longitudinal pericardiectomy was performed and the patient made an uneventful recovery.

Adult↗
PubMedDate not supplied

Liver transplantation with a twenty-four hour delay and an initial low dose of cyclosporine.

BACKGROUND/AIMS: Cyclosporine A based immunosuppression protocols have improved the results of liver transplantation. However, there is no general agreement concerning the most appropriate initial dose of cyclosporine or the precise moment we should start its administration. MATERIALS AND METHODS: Two cyclosporine A administration procedures in liver transplantation were analyzed by means of a prospective study using 91 consecutive patients and dividing them into two groups: Group A: 50 consecutive transplants in which cyclosporine was started since the surgery at 4 mg/kg/day, and Group B: the following 41 consecutive transplants in which cyclosporine was started 24 hours after transplantation at 2 mg/kg/day. RESULTS: Cyclosporine levels were higher in Group A in the first month (without significant differences). There were differences in the need for hemodialysis (14% vs 0%, p < 0.01), in the length of time (h) on mechanical ventilation (147.5 +/- 36 vs 48.7 +/- 15.7, p < 0.05) and in the time (d) spent in intensive care (10.5 +/- 1.6 vs 6.5 +/- 0.8, p < 0.05). There were no differences in the incidence of acute rejection, arterial blood pressure, septic and neurological complications, or in the actuarial survival rate for patients and grafts at 36 months. CONCLUSIONS: Delayed administration of cyclosporine simplifies the treatment of patients in the first 24 hours, it has several beneficial features and does not appear to be associated with a high acute rejection rate. On the basis of these results, our group has adopted delayed and low-dosage cyclosporine procedure.

Creatinine↗