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Biomedical subjects

F Fernandez

Publications and source records attributed to F Fernandez.

At least 55 records · Page 3Linked to original sources
PubMed1997

The influence of diet on the mucin carbohydrates in the chick intestinal tract.

The presence of nutrients in the intestinal lumen is a major factor influencing bacterial colonization in poultry. This study was conducted to investigate the effects of poultry feed on viscosity of intestinal contents and on mucin carbohydrates by comparing jejunal supernatants and the histochemical composition of goblet cells in chicks reared to 5 weeks of age on either a conventional maize-based diet or a wheat-based diet or a wheat diet supplemented with 0.1% xylanase. Regional differences in the distribution of the neutral, carboxylated and sulphated mucins were demonstrated using conventional histochemical techniques, while a panel of lectins was used to study alterations in glycoconjugate synthesis of mucins in chicks fed different diets. 1) Feeding a diet supplemented with xylanase lowered the viscosity but increased the amount of neutral, carboxylated and sulphated mucins in the jejunum. 2) In chicks fed a maize-based diet, neutral mucins increased in the surface and upper crypt goblet cells of the small and large intestines but decreased in the caecum. 3) Feeding a diet supplemented with xylanase modified crypt-surface glycosylation of N-acetylglucosamine residues and resulted in loss of sialic acid residues in the small and large intestines. These results indicate that the constituents of poultry feed, in particular the consumption of a diet supplemented with xylanase, lead to changes in intestinal viscosity and mucin composition which are associated with alterations in the goblet cell glycoconjugates of the chick intestinal tract.

Animal Feed↗
PubMed1997

Evaluation of the influence of supplementing the diet with mannose or palm kernel meal on Salmonella colonisation in poultry.

1. The dietary inclusion of 15 and 25 g/kg mannose was associated with a reduction in the numbers of Salmonella enteritidis (PT4) in the caecal contents of chicks challenged by the food. The same benefit was not recorded for S. infantis, possibly because this strain, unlike S. enteritidis PT4, lacked mannose-sensitive fimbriae. 2. The addition of 25 g/kg palm kernel meal (PKM), but not 20 g/kg desiccated coconut, to the food reduced the degree of salmonella colonisation in the intestinal tract of broiler chicks given diets contaminated with S. kedougou or S. enteritidis from the day of their arrival from the hatchery. 3. The beneficial effect of PKM was also demonstrated at an inclusion rate of 5 g/kg and was similar for preparations with a particle size of either < 150 microns or < 300 microns. 4. Day-old birds challenged orally with S. enteritidis and given food supplemented with 25 g/kg PKM, became clear of infection by 3 weeks of age while birds given unsupplemented food remained infected. 5. These preliminary results suggest that the inclusion of PKM, which contains inter alia, oligosaccharides containing mannose, in the diet of chicks may reduce the extent to which the intestine is contaminated with salmonellas.

Animals↗
PubMed1997

Urovirulence determinants in Escherichia coli strains causing prostatitis.

To define the urovirulence properties of Escherichia coli strains producing prostatitis, E. coli strains isolated from men with acute (7 strains) or chronic (23) prostatitis were compared with E. coli isolates from women with pyelonephritis (30), acute cystitis (60), or complicated urinary tract infection (UTI; 30). Strains from prostatitis patients were significantly more likely to express hemolysin than were strains causing complicated UTI (73% vs. 43%; P = .02) and more often demonstrated hybridization with the cytotoxic necrotizing factor-1 (CNF-1) probe (63%) than did strains from women (44%-48%). P fimbrial expression was highest among pyelonephritis (73%) and prostatitis strains (53%) and lowest among E. coli from women with complicated UTI (23%) and cystitis (30%; P < .05, prostatitis strains vs. either of the latter 2 groups). Results suggest that E. coli strains producing prostatitis generally possess urovirulence profiles similar to those of strains from women with acute uncomplicated pyelonephritis and that hemolysin and CNF-1 are especially prevalent in prostatitis strains.

Acute Disease↗
PubMed1997

Psychiatric perspective of pediatric human immunodeficiency virus infection.

BACKGROUND: Infection due to human immunodeficiency virus (HIV) has become a chronic disease of childhood, with increasing rates among adolescents and longer survival of those infected. This illness and its victims present a continuing challenge to the medical community. METHODS: We used computerized literature searches (MEDLINE and AIDSline) to identify research and review papers from medical, psychiatric, and psychology journals; we obtained statistics directly from the Centers for Disease Control and Prevention, National AIDS Clearinghouse. RESULTS: This overview of the topic includes epidemiology, transmission, diagnosis, psychiatric and neuropsychiatric manifestations, intervention, and the impact on families, caretakers, and health care workers. CONCLUSIONS: To psychiatrists, this disease presents the epitome of the biopsychosocial model, encompassing the biology of a viral disease with psychiatric manifestations, complicated by the societal place in which it has become entrenched.

Adolescent↗
PubMed1996

A new stress protein: synthesis of Schizosaccharomyces pombe UDP--Glc:glycoprotein glucosyltransferase mRNA is induced by stress conditions but the enzyme is not essential for cell viability.

We have identified and begun the characterization of the gene encoding UDP-Glc:glycoprotein glucosyltransferase in Schizosaccharomyces pombe. This gene, here designated gpt1, codes for a polypeptide having a signal peptide of 18 amino acids followed by 1429 amino acids with no transmembrane domain, as expected for a soluble protein of the endoplasmic reticulum (ER). The C-terminal tetrapeptide PDEL most probably corresponds to a novel ER retention signal in this fission yeast. Synthesis of the corresponding mRNA was induced 2- to 9-fold by conditions known to affect glycoprotein folding in the ER (e.g. heat shock, culture in the presence of a Ca2+ionophore, 2-mercaptoethanol or inhibitors of protein N-glycosylation such as tunicamycin or 2-deoxyglucose). This is the first evidence obtained in vivo that supports the proposed involvement of the enzyme in the quality control of glycoprotein folding in the ER. Thus far, the said involvement was inferred solely from the ability of the enzyme to glucosylate misfolded but not native glycoproteins in cell-free assays. The gpt1 gene was disrupted and gpt1- cells were found to be viable. Moreover, no significant differences in the growth rate patterns at 18, 28 or 39 degrees C or in cell morphology between gpt1+ and gpt1- cells were observed, although they differed slightly in size.

Amino Acid Sequence↗
PubMed1996

Rotavirus subunit vaccines.

We evaluated rotavirus subunit vaccines for use in humans and animals. Insect cells were co-infected with combinations of individual baculovirus recombinants expressing human, bovine or simian rotavirus VP2, VP4, VP6 or VP7 to produce virus-like particles (VLPs). To determine whether immunization with VLPs could induce active protective immunity, VLPs were administered parenterally to rabbits, and the immune response and protection from rabbit ALA rotavirus challenge were evaluated. Complete or partial protection was attained, showing that parenteral immunization with VLPs induces active protective immunity. We also examined whether heterotypic immune responses could be induced with a limited number of broadly reactive VP7 proteins or with chimeric particles (multiple VP7 types on individual particles). The feasibility of this approach was determined by immunizing mice with VLPs containing a G3 VP7 or G1 VP7 and chimeric G1/G3 VLPs. Broadly reactive neutralizing antibody was induced by the G1 VLPs. VLPs also have been successfully used to boost lactogenic (colostral and milk) immunity in dairy cows. Taken together, these results show that VLPs can be effective immunogens in rabbits, mice and dairy cattle when administered parenterally, a limited number of VLPs may be sufficient to produce a broadly protective vaccine, and G3 VLPs may serve as an effective subunit vaccine for use in bovines.

Animals↗
PubMed1996

Source abundances of ultra heavy elements derived from UHCRE measurements.

A total of 205 tracks have been located, measured, and positively identified as originating from Ultra Heavy (Z > or = 65) cosmic ray ions with energies over 2 GeV/amu in the 10 UHCRE plastic track detector (mainly Lexan polycarbonate) stacks studied by our Group. About 40 values of reduced etch rate S have been obtained along each of these tracks. A method based on determining the gradient of S, together with calibration in accelerators, is used to determine the charge of each ion resulting in one of such tracks to obtain the charge spectrum of the recorded Ultra Heavy ions. The abundance ratio of ions with 87 < or = Z < or = 100 to those with 74 < or = Z < or = 86 as well as that of ions with 81 < or = Z < or = 86 to those with 74 < or = Z < or = 80 are calculated at 0.016 and 0.32, respectively, which agree with the values obtained from measurements in the HEAO-3 and Ariel-6 experiments. The abundance ratio of ions with 70 < or = Z < or = 73 to those with 74 < or = Z < or = 86 is also calculated, but its value (0.074) did not seem to be significant because of our detectors' low registration efficiency in the charge range 70 < or = Z < or = 73. A computer program developed by our Group, based on the Leaky Box cosmic ray propagation model, has been used to determine the source abundances of cosmic ray nuclei with Z > or = 65 inferred from the abundances measured in the UHCRE. It appeared that r-process synthesized elements were overabundant compared to the Solar System abundances, as predicted by other authors.

Actinoid Series Elements↗
PubMed1996

Prevalence of abnormal levels of serum tumour markers in elderly people.

The study was conducted to evaluate the prevalence of abnormal levels of several serum tumour markers in an institutionalized elderly population. Serum tumour markers assay of carcinoembryonic antigen (CEA), the carbohydrate antigens CA 19-9, CA 72-4 and CA 15-3 (Enzymun-test, Boehringer Mannheim GmbH Diagnostic), alpha-fetoprotein (AFP) and prostate specific antigen (PSA) (Abbot Diagnostic Division) were performed in 228 unselected, institutionalized elderly subjects, whose mean age (SD) was 82.4 (5. 79) range (66-99 years). Patients with acute or neoplastic diseases were excluded from the study. The serum markers were also measured in 52 healthy young adults (controls). Using the established threshold values, 92 subjects (40%) were found to have at least one elevated marker. PSA was elevated in 33%, CA 19-9 in 16%, CEA in 11. 5%, CA 15-3 in 11%, CA 72-4 in 8% and AFP in 3%. We found a significant difference in the serum levels between the two groups for CEA, CA 19-9. CA 15-3, and PSA (p < 0.0001). Healthy aged people appear to have an elevated prevalence of elevated levels of serum tumour markers. The results suggest that apart from PSA, elevated antigen levels in elderly subjects are related to the ageing process itself rather than to occult pathology.

Aged↗
PubMed1995

Clinical study of the effects of latissimus dorsi muscle flap stimulation after cardiomyoplasty.

BACKGROUND: Beneficial hemodynamic effects after dynamic cardiomyoplasty have been inconsistently demonstrated, and the effects seen may be due to the wrap itself, to flap stimulation, or both. The aim of this study was to determine whether flap stimulation per se acts as a systolic active process after cardiomyoplasty. METHODS AND RESULTS: Catheterizations were performed in 13 patients 14.4 +/- 7 months after cardiomyoplasty. New York Heart Association functional class decreased from 3.3 to 2.1 after the procedure (P = .0005). Hemodynamic evaluations were first performed with the stimulator on in the 2:1 mode and then after the stimulator had been off for at least 24 hours. Left ventricular (LV) ejection fraction increased from 25.1 +/- 6% before surgery to 28.2 +/- 6.7% with the stimulator on after cardiomyoplasty (P = .04). When stimulation was stopped, there was no change (P > .05) in indexes of systolic or diastolic LV function (peak systolic LV pressure, LV ejection fraction, peak positive dP/dt, peak negative dP/dt, or tau). Pulmonary capillary wedge pressure and cardiac index were unchanged when stimulated and nonstimulated settings were compared (P > .05). However, a remarkable heterogeneity of individual responses was observed. Ejection fraction and cardiac index decreased with the stimulator off in 3 patients, but peak positive dP/dt decreased in 6 patients; diastolic function deteriorated in 2 patients, but a slight improvement was noted in 3 patients. Cardiothoracic ratio, echocardiographic LV end-diastolic dimension, and fractional shortening remained unchanged between immediate (< 1 month) and long-term (36.7 +/- 25.9 months) postoperative evaluations. CONCLUSIONS: In the majority of our patients, there was no short-term hemodynamic benefit of flap stimulation; therefore, we conclude that the efficacy of cardiomyoplasty may be a consequence of a passive "girdling effect," which limits the progression of ventricular enlargement and further deterioration of ejection fraction.

Adult↗
PubMed1995

Therapeutic effect of early thymic irradiation in (NZB x NZW)F1 mice, associated with a selective decrease in the levels of IgG3 and gp70-anti-gp70 immune complexes.

The lupus-prone (NZB x NZW)F1 female mice (NZB/W) develop an autoimmune disease characterized by production of autoAb and fatal glomerulonephritis. Since it has been previously shown that total lymphoid irradiation has a beneficial effect in this model, we have analyzed whether early thymic irradiation (ETI) could improve the course of the lupus-like syndrome in these mice. NZB/W mice received thymic irradiation (4500 rads) beginning at 10 weeks of age, prior to the onset of autoimmune manifestations. Then, they were evaluated for survival, renal histology, and serological markers of autoimmunity, in comparison to nonirradiated NZB/W females. The treatment with ETI improved nephritis and survival in NZB/W mice: 50% mortality was observed at 12 months in irradiated mice and at 9 months in untreated mice. This improved survival could not be attributed to a reduction in the titers of anti-dsDNA Ab nor in the levels of total immune complexes which were essentially identical in both groups. By contrast, this improvement was related to a selective normalization in the serum levels of IgG3 and gp70-anti-gp70 immune complexes (gp70IC) in ETI NZB/W female mice as compared to that seen in nonirradiated NZB/W females. These data show the therapeutical effect of ETI and support the pathogenic role of IgG3 and gp70IC in the development of glomerulonephritis in NZB/W mice.

Animals↗
PubMed1995

Laparoscopic procedure for suspected appendicitis. A prospective study in 283 consecutive patients.

Between September 1990 and December 1993, 283 consecutive patients were admitted with clinical symptoms of acute appendicitis. These patients underwent primary laparoscopic approach so that an appendicectomy could be performed by this method. In 49 cases (17.3%), primary laparoscopic examination corrected the preoperative diagnosis and the appendix was left in situ. Appendicectomy was performed in 234 cases (149 women, 85 men) with a mean age of 30 years. Requirement for open surgery occurred in 29 cases. The main cause of unsuccessful procedures was inflammation due to local or generalized peritonitis. Median operative time for a successful procedure was 60 min (range, 25-160). Four postoperative complications (one related to laparoscopic procedure), one case of wound infection, and no mortality resulted. After laparoscopic appendicectomy, the median hospital stay was 3 days (range, 1-16). These results suggest that a laparoscopic approach for suspected appendicitis is reliable, allowing abdominal exploration and safe appendicectomy.

Acute Disease↗
PubMed1995

Role of laparoscopic surgery in the management of acute abdomen in the HIV-positive patients.

Emergency open laparotomy in patients infected with HIV is accompanied by high mortality. The authors investigated the potential role of a laparoscopic approach for the management of acute abdomen in such patients. Prospectively, 10 patients with HIV disease (9 with AIDS) underwent laparoscopy for acute abdomen. The treatment was exclusively laparoscopic in 6 patients. A conversion to laparotomy was necessary in 4 patients but through guided elective incision in 3 of them. The postoperative course was uneventful in all patients but 1, who died. We advocate a laparoscopic approach, when feasible, as an initial step in the management of acute abdomen in HIV-positive patients.

Abdomen, Acute↗
PubMed1995

Effects of methylphenidate in HIV-related depression: a comparative trial with desipramine.

This report is a randomized, double-blind, comparative trial of desipramine with the psychomotor stimulant methylphenidate. Twenty HIV antibody-positive patients with depressive symptoms were randomly assigned to either drug. After individual dose titration, the mean daily dose of desipramine was 150 mg. and methylphenidate 30 mg. daily. The differences in responses between desipramine and methylphenidate were not statistically significant on various measures of depression. The antidepressant effect of methylphenidate did not occur any faster than that of desipramine. Both significantly reduced depressive and anxious symptomatology over the blinded portion of the treatments. Thus, methylphenidate relieves depressive symptomatology with efficacy similar to that of desipramine, offering an alternative to patients who are unable to tolerate standard tricyclic antidepressant therapy. The dopaminergic effects of methylphenidate are likely to mediate its antidepressant effects.

Adult↗
PubMed1995

The management of depression and anxiety in the elderly.

The most common psychiatric disorders in later life, with the exception of dementia, are depression and anxiety. Often underdiagnosed or simply accepted with resignation as an inevitable part of aging or as an unavoidable complication of other constitutional illnesses, these disorders contribute to excess disability in older patients and further compromise their quality of life. This report discusses depression and anxiety in the growing elderly population--its prevalence, detection methods, diagnostic considerations, and present interventions.

Age Factors↗
PubMed1995

[Restenosis: physiopathology, treatments and prevention].

Despite fifteen years of extensive research, we still do not know how to predict or prevent restenosis. Angioplasty induces lesions in the intima, media and sometimes adventitia, resulting in a cicatricial process comprising proliferation and migration of smooth muscle cells towards the intima and secretion of extracellular matrix, leading to the formation of a neointima. Since angioplasty is associated with the simultaneous development of neointimal hyperplasia and restenosis, a cause and a effect relationship has therefore been proposed between neointimal hyperplasia and restenosis. All the restenosis prevention strategies based on inhibition of smooth muscle cell proliferation, which successfully limited restenosis in animal models have failed in man, due to the hazardous extrapolations from experimental models which are very different from the atheromatous lesions observed in man, rather than to the use of animal models in general. It is reasonable to wonder whether we have not selected the wrong target: is smooth muscle cell proliferation really responsible for restenosis? Experimental results supported by histological and ultrasonographic data in man, show that the cicatricial process which induces restenosis consists of constrictive remodelling, which decreases the perimeter of the external elastic lamina and the lumen. The use of stents appears to be the primary strategy designed to limit restenosis and prevent constrictive remodelling in man, even if it stimulates neointimal hyperplasia. Progress in the understanding of the mechanisms of postangioplasty remodelling open new perspectives in the prevention of restenosis.

Angioplasty, Balloon, Coronary↗
PubMed1994

Epidemiological markers of Acinetobacter baumannii clinical isolates from a spinal cord injury unit.

During a period of 28 months, 114 isolates of Acinetobacter baumannii obtained from urine samples of 57 patients, were recovered in a Spinal Cord Unit; an unusual increase in the number of A. baumannii isolates was observed between February 1991 and January 1992. Six different typing methods [biotyping, antimicrobial susceptibility, whole cell and cell-envelope protein analysis, plasmid analysis and chromosomal DNA analysis by pulsed-field gel electrophoresis (PFGE)] were used to study the isolates to establish any potential relationships among them. Chromosomal DNA analysis by digestion with ApaI and separation of the fragments by PFGE was the most powerful tool to determine the relatedness of isolates. The results suggest that the isolates from 1991 and 1992 may have originated from strains present in 1990 that subsequently acquired resistance to amikacin and tobramycin during the epidemic.

Acinetobacter↗