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Biomedical subjects

M Fernandez

Publications and source records attributed to M Fernandez.

At least 199 records · Page 11Linked to original sources
PubMed1975

[The role of temperature in phenotypic expression of amphibian embryos Pleurodeles waltlii homozygous for the heat-sensitive mutation ac (caudal ascites)].

1. At the feeding stage (st. 38), a high percentage (79%) of Pleurodeles homozygous ac/ac larvae show bent tails after a persistent ascitic blister in the dorsal part of the fin, when embryonic development occurred at 12 degrees C; about only 25% of them are affected by abdominal and pericardic ascites; about 40% can feed and survive. The larval phenotype is very different when embryonic development occurred at 23 degrees C, in which case tail growth appears to be normal, but 95% larvae die, due to ascitic fluid collection in the abdominal and heart regions, marked anaemia and microcephaly. 2. The exchange of posterior neural plates and dorso-lateral epidermis between normal and mutant neurulae has shown that the localization of the blister in the dorsal fin is not dependent on autonomous properties of the mutant dorsal tissues, but should be considered as resulting from general disturbances in the mutatnt organism. 3. Experiments were performed, involving a temperature shift from 12 to 23 degrees

Age Factors↗
PubMedDate not supplied

Transplacental transport of netobimin metabolites in ewes.

Neither netobimin (NTB) nor its metabolite albendazole (ABZ) were found in plasma after an oral administration of 20 mg/kg of NTB to pregnant ewes during the last third of gestation. ABZ metabolites, albendazole sulphoxide (ABZSO) and albendazole sulphone (ABZSO2) were found in plasma 30 min and 2 h, respectively, after administration. The maximal plasma concentration (Cmax) of ABZSO was detected at 11.6 +/- 1.0 h and for ABZSO2 at 16.5 +/- 2.3 h. The plasma levels of the latter remained constant for 36 h, and decreased as ABZSO was removed from the blood. Jugular plasma levels of both metabolites did not differ significantly from those observed in the ovarian vein, suggesting that there were no exchanges between foetal and placental tissues. Both metabolite concentrations were similar in the umbilical vein and artery and in the amniotic and allantoic fluids, their values were half the maternal plasma concentration, leading to the conclusion that there was transplacental movement of metabolites. Both metabolites reached the foetus and could be responsible for the teratogenicity of NTB in sheep.

Albendazole↗
PubMedDate not supplied

Lutzomyia verrucarum can transmit Leishmania peruviana, the aetiological agent of Andean cutaneous leishmaniasis.

In much of the endemic area for cutaneous leishmaniasis (uta) in the Peruvian Andes, the only 2 anthropophilic sandfly species present are Lutzomyia peruensis and Lu. verrucarum. On the basis of a single confirmed isolation of Leishmania peruviana (the aetiological agent of uta) from a wild Lu. peruensis, and apparent associations between sandfly abundance and the incidence of uta, it is generally believed that Lu. peruensis is the most important vector. In this paper, a potential role for Lu. verrucarum in the transmission of uta is indicated by laboratory experiments which show that this species is vectorially competent for L. peruviana. Individual or pooled colonized sandflies were permitted to take a second blood meal on 22 susceptible golden hamsters at varying intervals after feeding on hamsters previously infected with L. peruviana. Transmission was achieved by a single infected sandfly (of a total of 59) following a 15 d incubation period. Transmission was recognized by the characteristic clinical response (footpad swelling) associated with hamsters which have been inoculated with L. peruviana, and by the presence of parasites in aspirates made from the swollen footpad, detected by the polymerase chain reaction (PCR) and by parasite isolations in biphasic blood-agar culture medium. The identity of the parasite isolates was also confirmed by PCR (specific for parasites in the L. braziliensis complex). This is the first reported experimental transmission of L. peruviana by any sandfly species.

Animals↗
PubMedDate not supplied

A comparison of normal, bipolar and seasonal affective disorder subjects using the Seasonal Pattern Assessment Questionnaire.

The Seasonal Pattern Assessment Questionnaire is an instrument for retrospective self-rating of change in mood and vegetative functions with the seasons. It has been used in studies to identify and characterise patients with Seasonal Affective Disorder (SAD) in three countries. In this paper, the test-retest reliability of all items and the sensitivity to differences between groups have been investigated. Clear differences were found between the SAD group and a normal group. A group of bipolar affective disorder patients had intermediate scores on reported seasonal changes between the normal and SAD groups. All groups reported significant changes in mood and vegetative functions during the winter in the direction symptomatic for SAD suggesting that SAD patients may suffer an exaggerated form of a normal seasonal variation.

Bipolar Disorder↗
PubMedDate not supplied

Neurodevelopmental outcomes of infant multivisceral transplant recipients: a longitudinal study.

UNLABELLED: This longitudinal investigation compares cognitive and physical capabilities of transplant recipients, both before and after receiving an intestinal transplant. METHODS: Using the Bayley Scales of Infant Development, we conducted pretransplant and posttransplant assessments on nine children (4 males, 5 females) who received either an isolated intestine, combined intestine and liver, or multivisceral transplants, with a mean age at transplant of 18 months (range 8-29) and a mean time posttransplant of 2 months (range 1-4 months). RESULTS: Scores on the Mental Developmental Index reflected that a majority (55.6%) of patients who scored in the significantly delayed range prior to transplant remained in the significantly delayed classification after receiving a transplant. In addition, 33.3% showed a decrease in their mental classification; either from "mildly delayed" to "significantly delayed" or from "within normal limits" to "mildly delayed". Results on the Motor Developmental Index demonstrated that 78% of recipients had significant delays both before and after receiving a transplant, while 11.1% fell one standard deviation after transplantation. We found that the majority of children who experience developmental delays prior to transplant are still experiencing delays when they are discharged from inpatient care. In addition, those children receiving multivisceral transplantations, as opposed to an isolated bowel, may be at a much greater risk of developing and retaining both cognitive and physical delays. Early neurodevelopmental evaluations of these patients is essential for early parental education and compliance with early intervention services to maximize potential recovery and ability to obtain normal development.

Child Development↗
PubMedDate not supplied

Neuodevelopmental outcomes for children transplanted under the age of 3 years.

UNLABELLED: Our previous investigations on neurodevelopmental outcomes for intestinal transplanted infants revealed that while some children were able to achieve a normal developmental outcomes, most children suffered from significant motor delays and several experienced severe cognitive delays. In our current investigation, we were especially interested in children who are transplanted before the age of 3 years because the impact of the chronic illness and nutrition impairment on the infant's developing brain may be more severe than those children who receive a liver transplant. METHODS: We evaluated 34 infants using the Bayley Scales of Infant Development. Twenty-seven children received a liver/intestine or multivisceral transplant and seven received a liver transplant. RESULTS: Comparison of the two groups revealed that children receiving an intestine/multivisceral transplant have much poorer outcomes. Seventy-four percent of these children were significantly delayed mentally compared to only 57.14% of the liver transplant infants. Furthermore, 42.86% of the liver-transplanted infants were actually functioning in the normal range posttransplant. The intestinal/multivisceral transplant infants' motor development shows the most striking difference, with 96.3% being severely delayed as compared to liver transplant infants in whom only 71% experienced serious delays. The neurodevelopmental impact of organ failure and transplant before the age of 3 years may depending on the type of organ transplant. Our study found that it may be more likely to expect a good outcome for liver transplant patients than for intestinal and multivisceral transplanted infants. This difference maybe due to the overall severity of the disease and the possible impact of nutritional deficits early in infancy.

Child Development↗
PubMedDate not supplied

Short-term outcomes in open vs. laparoscopic herniorrhaphy: confounding impact of worker's compensation on convalescence.

Over a 28-month period, 123 patients with a unilateral inguinal hernia were recruited into a randomized controlled trial comparing open herniorrhaphy (OH) to laparoscopic inguinal herniorrhaphy (LH). The primary end point was duration of convalescence. Sixty-five patients underwent OH and 58 underwent LH. Both groups were well matched for all baseline parameters, although LH patients anticipated a shorter convalescence than OH patients (14.3 +/- 9.4 days vs. 18.5 +/- 10.8 days; P = 0.021). The median duration of hospital stay was one day in both groups. No difference was observed in the duration of convalescence (LH 9.8 +/- 7.4 days; OH 11.6 +/- 7. 7 days) across groups. However, when the data were analyzed after removing patients receiving disability ("worker's") compensation (21 patients), patients undergoing LH recovered on average 3 days faster (LH 7.8 +/- 5.6 days; OH 10.9 +/- 7.5 days; P = 0.02). Patients not receiving worker's compensation appear to have a shorter convalescence after LH compared to OH. Disability compensation is a major confounding variable in determining convalescence and needs to be controlled for in any future trial design.

Confounding Factors, Epidemiologic↗
PubMedDate not supplied

Dysplastic nevi of the scalp and forehead in children.

To determine if there is a significant difference in the relative frequency and degree of atypia of sporadic dysplastic nevi from the scalp, face, and neck area in children as compared with nevi from the rest of the body, we reviewed 99 consecutive biopsy specimens of melanocytic nevi from the scalp, face, and neck areas in children less than 18 years of age and compared them with 95 consecutive cases of nevi from other areas of the body in children of the same age. Large numbers of the nevi biopsied from the scalp (13 of 31; 41.93%) and forehead (2 of 10; 20%) were dysplastic. The number of dysplastic nevi from the neck (1 of 58; 1.72%) was not assessed as very different from the incidence found in other regions of the body, where 7 dysplastic nevi (7.36%) from a total of 95 nevi were found. Of the 13 dysplastic nevi from the scalp, 9 showed minimal atypia and 4 showed moderate atypia. No nevi with severe atypia were found. Many pigmented nevi from the scalp and forehead in children in this study were dysplastic. This finding points out the importance of examining the scalp of children for the presence of dysplastic nevi. The majority of nevi from the neck were common nevi.

Adolescent↗
PubMedDate not supplied

Mucosal cytokine and antigen-specific responses to Cryptosporidium parvum in IL-12p40 KO mice.

Studies of cellular immune responses to Cryptosporidium parvum have been limited in part by lack of suitable animal models. IL-12p40(-/-)mice are susceptible to initial infection with C. parvum but recover within 2 weeks, rendering the animals resistant to reinfection. Because the host responses that determine duration and severity of primary infection are not yet understood, we studied the cellular immune response to primary infection with C. parvum in IL-12p40(-/-)mice and also explored possible mechanisms for this response. Female IL-12p40(-/-)mice were inoculated with 10,000 oocysts. Uninfected age-matched mice served as controls. At different time intervals following exposure to oocysts, mice were sacrificed and their intestine, spleen, and mesenteric lymph node tissues were harvested. Cellular immune responses to C. parvum were characterized. Infection of IL-12p40(-/-)mice induced changes in the gene expression of the cytokines IFN-gamma, IL-4, IL-15, IL-18, TNF-alpha and TGF-beta during primary infection. There was also a significant increase in total numbers of lymphocytes and CD19/CD62L-expressing cells in mesenteric lymph nodes. These MLN cells exhibited increased antigen-specific proliferation and cytokine production (IL-6 and IFN-gamma) levels when stimulated in vitro. These observations delineate the cellular immune responses during acute C. parvum infection of the IL-12p40(-/-)mouse model.

Animals↗
PubMedDate not supplied

Coagulation, fibrinolytic and kallikrein systems in neonates with uncomplicated sepsis and septic shock.

This study evaluates the contact system, coagulation inhibitors and fibrinolysis in 23 full-term newborns with sepsis (8 with septic shock). The results were compared with a group of 20 healthy newborns. Blood samples were obtained at the time of clinical diagnosis and 3 days after the antibiotic therapy was started. The results showed that: severe infection was associated with activation of the contact system, depletion of anticoagulant proteins and elevation of C4b-binding protein levels. There was a shift in protein S to the complexed inactive form, and the thrombin-antithrombin complexes increased. These changes occurred in parallel to both activation and inhibition of fibrinolysis. These changes were more pronounced in the septic shock patients than in nonshock neonates. After therapy, this procoagulant state decreased among survivor patients while in those who died, the abnormalities in coagulation did not improve. Our study suggests that neonatal sepsis induces a hypercoagulable state that persists in nonsurvivor neonates despite a correct treatment.

Anti-Bacterial Agents↗
PubMedDate not supplied

IgG and IgE antibodies in subjects allergic to penicillins recognize different parts of the penicillin molecule.

BACKGROUND: IgE and IgG antibodies to penicillins can have different specificities. However, this response, including the recognition of the different parts of penicillin, has never been studied in the same subject. OBJECTIVE: Study of the specificity of IgE and IgG antibodies and the relevant parts of the penicillin molecule that contribute to the hapten binding site in sera from human. METHODS: Specific IgE antibodies were determined by RAST and specific IgG antibodies by ELISA. The recognition of the different molecules was studied by inhibition studies. RESULTS: Seven sera with IgG and IgE antibodies to amoxicillin and benzyl penicillin were analyzed. IgE antibodies recognized mainly two different epitopes: in one, the side chain was a relevant part of the epitope, in the other, it was the nuclear portion. IgG antibodies recognized the nuclear portion in all instances. In the same subject, antibodies of different isotype and specificity were found. CONCLUSIONS: Subjects who develop simultaneously IgE and IgG antibodies to penicillins show different specificities. This proves that different populations of antibodies recognize different epitopes.

Antibody Specificity↗