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Biomedical subjects

F Fernandez

Publications and source records attributed to F Fernandez.

At least 19 recordsLinked to original sources

Inoue balloon usefulness in case of failure to stabilize bifoil catheter balloons during percutaneous mitral valvotomy.

A new bifoil balloon catheter has been used in the last 120 percutaneous mitral valvotomies carried out in our institution. The shaft segment between the two balloons of the bifoil catheter has been adjusted to the guide-wire diameter, allowing its introduction through a 14F sheath. This thinner shaft does not always offer enough back up to the balloons during inflation. An Inoue balloon replaced an unstable bifoil balloon in 5 cases of mitral dilatation failure due to balloon instability, regularly providing firm stability until full balloon inflation.

Adult

Enzyme immunoassay for Q fever: comparison with complement fixation and immunofluorescence tests and dot immunoblotting.

Enzyme-linked immunosorbent assays (ELISA) for the detection of specific immunoglobulin G (IgG) and IgM antibodies were developed by using purified Coxiella burnetii cells. Variables, including type of microtiter plate, blocking agent, incubation conditions, antigen stability, and substrate type, were examined to achieve optimal ELISA performance. The reliabilities of the assay systems were compared with those of complement fixation (CF) and enhanced immunofluorescence (EIF) tests with 600 human serum samples from defined clinical cases of Q fever, routine samples, and serum specimens from farmers. ELISA and EIF test results agreed in all cases. Dot immunoblotting was also used to test some of these sera and gave a rapid, qualitative result, which agreed with ELISA and EIF test results in all cases. No instances were found in which both ELISA and EIF test results were negative and the CF test results was positive. However approximately 5% of the sera were positive by ELISA and the EIF test while the CF test result was either negative or unreadable because of serum anticomplementary activity. We conclude that dot immunoblotting is a useful screening test, whereas ELISA and the EIF test are both rapid and sensitive tests when used for the serodiagnosis of Q fever and should be considered to be replacements for the CF test.

Antibodies, Bacterial

Protein C, protein S and C4b-binding protein in neonatal severe infection and septic shock.

We have studied the behaviour of total protein S, free protein S, protein C and C4b-binding protein fifteen neonates with severe infections, eight with septic shock and in a group of ten healthy newborns. Protein C was decreased in shock and septic patients, but only the shock group showed significant differences compared to normal neonates. Total protein S was normal in both groups of patients, although free protein S had significantly lower values in shock and nonshock infants. C4b-binding protein was higher than normal in septic and shock patients compared to the control group. Decreased values of protein C and free protein S can be explained by the activation of coagulation and their subsequent consumption. On the other hand, the increased levels of C4b-binding protein can affect the distribution of protein S in plasma, producing a shift in protein S to the complexed inactive form. These findings can contribute to an increased risk of microthrombosis during neonatal sepsis.

Carrier Proteins

Kidney cortical necrosis induced by mitomycin-C: a morphologic experimental study.

Experimental studies on mitomycin-C nephrotoxicity are scanty and mention the occurrence of cortical hemorrhage, tubular necrosis, or hydronephrosis secondary to papillomatous hyperplasia of the uroepithelium. To our knowledge, only one experimental study has mentioned morphological lesions similar to the hemolytic uremic syndrome in the human. In the present study 40 female Wistar rats were studied following unilateral renal perfusion of the left kidney with 2 mg/kg of mitomycin-C. Renal lesions corresponded to cortical necrosis with the presence of large bizarre nuclei. The presence of these nuclear atypias supports a direct toxic effect (alkylation) of the mitomycin or its metabolites on cells.

Animals

Myasthenia gravis in a child with sequelae of opsoclonus-myoclonus syndrome.

Immune-mediated myasthenia gravis occurred in a 13-month-old girl who had sequelae of an opsoclonus-myoclonus syndrome. She had an abnormal Raji cell assay along with elevated antiacetylcholine receptor and antithyroglobulin antibodies. No evidence of an associated malignancy was found with either condition. Clearly, the co-occurrence of two diseases within a single patient does not establish a common pathogenesis. Nevertheless, this is a provocative association and may point to an immunologically mediated process in the opsoclonus-myoclonus syndrome.

Female

Fluoroscopic guidance in transseptal catheterization for percutaneous mitral balloon valvotomy.

A percutaneous mitral balloon valvotomy (PMBV) was attempted on 190 patients with fluoroscopic guidance of atrial septal puncture for transseptal catheterization; in 3 cases, the procedure could not be performed. The left atrium was always reached on the first attempt, when the relationship of the Brockenbrough needle to the aortic catheter was previously observed in 3 fluoroscopic views: anteroposterior, 45 degrees right anterior oblique, and lateral. The atrial septal puncture site was located immediately below the aortic valve level, probably in the fossa ovalis, for the first 80 patients, and at mid distance between the aortic valve level and the diaphragm for the last 110. Hemodynamic data were similar in both groups. Fluoroscopic guidance for atrial septal puncture seemed capital for patients with scoliosis or in whom a vascular distortion (e.g., advanced pregnancy, right inferior vena cava absence) prevented a perfect parallelism between the needle curve and the needle outer index.

Adult

Comparison of the immune response elicited by infectious and inactivated foot-and-mouth disease virus in mice.

The immune response to foot-and-mouth disease virus (FMDV) elicited by infection or immunization with inactivated virus in adult mice was examined. A model of adoptive transfer of immunocompetent cells was used for this purpose. The results presented here indicate that both short- and long-term secondary immune responses elicited by high doses of inactivated virus are indistinguishable, at the humoral or cellular level, from that observed after infection. The responses to inactivated or infectious virus were both efficiently mediated by B cells. However, immunization with low doses of inactivated virus induced a response which, although effective in aborting infection, was fully dependent on FMDV-specific T cell cooperation. These findings suggest that the different immune responses observed after infection and immunization are mainly the result of the different viral mass presented to the immune system in each case.

Animals

[Left bifascicular block and percutaneous mitral valvuloplasty].

In some patients, the inflation of balloons through the mitral orifice during percutaneous mitral valvuloplasties may impair intraventricular conduction. In some cases, this appears to correspond to a block of the anterior and middle network within the left branch of the bundle of His. This left "biblock" is characterized by extreme left axial deviation of AQRS, of about -60 to -70 degrees, with a QS aspect on D2 and D3, RS on V1 and R on V6 with no major prolongation of ventricular activation time. If this hypothesis is correct, it would support the "trifascicular" concept of the left branch of the bundle of His.

Adult

Endogenous N-nitrosation and cancer of the biliary tract.

Evidence is presented that N-nitroso compounds occur in bile from patients who have undergone surgery for gallstones or had gastrectomy and from unoperated persons. It is unlikely, therefore, that local formation of nitrosamines can account for the excess risk for gallbladder cancer in the first two groups. Gastric formation remains the likeliest hypothesis.

Bile

Psychopharmacotherapy of psychiatric syndromes in asymptomatic and symptomatic HIV infection.

It is evident that human immunodeficiency virus (HIV) infection is one of the most serious public health issues in decades. HIV infection compromises cell-mediated immunity which ultimately may result in the acquired immunodeficiency syndrome (AIDS). AIDS, to date, remains an incurable and progressively fatal disorder. HIV infection is spreading beyond the originally identified high-prevalence groups of gay/bisexual males, intravenous drug abusers, and recipients of infected blood or blood products. Today, more and more heterosexual males, women, adolescents, and children have been infected with this lethal virus. This report addresses some of the psychiatric complications associated with HIV infection and discusses the diagnostic and clinical management challenges that clinicians must face as they deal with the increasing population of HIV-infected patients. Depression, anxiety, psychosis, delirium, and dementia are commonly encountered disorders associated with HIV spectrum disorders which must be accurately identified and can be effectively managed with psychopharmacological interventions.

Acquired Immunodeficiency Syndrome

Fasted state impedes recovery of porcine hepatic oxygen consumption after warm hepatic ischemia.

The most effective means to prepare the hepatic donor liver for harvest, preservation, and transplantation are not known. Studies have shown that in combination with an injury to the liver, fasting reduces hepatic function. This study randomized 20 market pigs, 20 to 45 kg, to an overnight fast (fed group) or a 42-hour fast (fasted group). Under general anesthetic perfusion of the portal vein and hepatic artery were controlled. Studies were performed at high flow (30 ml/min/kg portal flow and 10 ml/min/kg arterial flow) and after a 90-minute period of warm ischemia (no flow). Flow was restored at 25% of the original (low flow), then increased to 50% of the original (medium flow). After the ischemic insult, the fed group improved hepatic oxygen consumption at a faster rate than the fasted group (p less than 0.05 by ANOVA). In addition, significant differences were noted between the fed and fasted groups in the amount of insulin delivered by the portal venous system to the liver (p less than 0.001 by ANOVA). Hepatic oxygen consumption was related to insulin delivery (r2 = 0.46; p less than 0.001) for both groups. The data suggest that acute changes in the nutritional status of both the donor and the recipient may affect hepatic recovery from ischemia.

Amino Acids

Preliminary report: follow-up after dynamic cardiomyoplasty.

Five patients were studied 5-13 months after dynamic cardiomyoplasty for refractory heart failure. In two, muscle flap stimulation caused a pronounced increase in cardiac index (mean 55%) and ejection fraction (mean 75%); no patient showed improvement in cardiac filling pressure. 2 years after surgery, one of the patients with haemodynamic improvement died from ventricular fibrillation, and histochemistry of the stimulated muscle flap revealed predominantly fatigue-resistant type I fibres, without evidence of fibrosis. In selected cases, dynamic cardiomyopathy could be of long-term benefit.

Adult

The many faces of AIDS: opportunities for intervention.

Social and cultural issues may have a profound impact on different populations' responses to the AIDS epidemic. To maximize their own effectiveness, clinicians need to be aware of special needs and concerns.

Acquired Immunodeficiency Syndrome

Dietary modification of potential vitamin K supply from enteric bacterial menaquinones in rats.

Rats given a low-fibre diet based on boiled white rice developed symptoms of severe vitamin K deficiency within 23 d. Inclusion of autoclaved black-eye beans (Vigna unguiculata) in the diet prevented the bleeding syndrome. To test the hypothesis that deficiency resulted from low phylloquinone intake exacerbated by inadequate production of menaquinones by the enteric bacteria, a follow-up experiment was carried out in which groups of rats were given an all-rice diet, a rice + beans diet or a stock diet. Rats on the all-rice diet had significantly lower faecal concentrations of the main menaquinone-producing bacterial species (Bacteroides fragilis and Bacteroides vulgatus) than animals on either of the other two diets. This coupled with the much lower faecal output on this diet suggests that total menaquinone production was low for the all-rice diet. The alterations in faecal flora were associated with several significant changes in caecal metabolism. Rats given the stock diet had much shorter caecal transit times and a considerably greater proportion of butyric acid in volatile fatty acid end-products than did rats on either of the other two diets.

Animals

Tolerance and efficacy of parenterally administered penicillin-streptomycin and orally administered amoxicillin or penicillin V for prophylaxis of experimentally induced streptococcal endocarditis.

A regimen of a single intramuscular dose of penicillin G-streptomycin was compared with regimens of three oral doses of amoxicillin and two oral doses of penicillin V to prevent Streptococcus sanguis endocarditis in rabbits with experimentally induced valvular heart lesions. Challenge doses of 10(4), 10(6), and 10(8) CFU of a strain of S. sanguis highly tolerant to penicillin and amoxicillin were used. The combination of penicillin and streptomycin was the only regimen tested that provided full protection even against the highest inoculum concentration. A single oral dose of penicillin V (36 mg/kg) or amoxicillin (50 mg/kg), two oral doses of penicillin V (36 and 18 mg/kg with a 7-h interval between doses), or six oral doses of amoxicillin (50 mg/kg followed by 8.5 mg/kg at 8-h intervals) protected recipients of the lowest inoculum concentration; protection diminished with increasing inocula. In contrast, administration of two high oral doses of amoxicillin (50 mg/kg) with a 10-h interval between doses provided full protection against challenge doses of 10(4) and 10(6) CFU, preventing endocarditis in 10 (66%) of 15 recipients of 10(8) CFU. All regimens evaluated were highly effective in preventing endocarditis when rabbits were challenged with 10(4) CFU. The combination of penicillin and streptomycin was the best regimen tested. Administration of two high oral doses of amoxicillin (50 mg/kg) with a 10-h interval between doses led to significantly fewer infections when compared with the other oral regimens when rabbits were challenged with 10(6) and 10(8) CFU.

Amoxicillin