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Biomedical subjects

M Hernandez

Publications and source records attributed to M Hernandez.

At least 91 records · Page 5Linked to original sources
PubMed1996

Very late presentation of vertically transmitted HIV-1 infection.

We describe a 13-year-old boy with a very late presentation of vertically transmitted HIV-1 infection. The mother, an intravenous drug user before pregnancy, was diagnosed with AIDS in 1987 when the boy was 6 years old. HIV infection in her son was never suspected or investigated. No other risk factors for this infection can be attributed to the boy. On diagnosis of the infection the boy had moderately severe respiratory symptoms, as classified in category B2 of the 1994 paediatric HIV infection definition, and virological replicative kinetics and the phenotype have been determined. Standard AZT therapy has improved the clinical symptoms, with negativization of plasma p24 Ag and HIV RNA. Clinicians should be aware of this form of presentation of HIV-1 infection to avoid further delay of proper therapy.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Cysticercosis: identification and cloning of protective recombinant antigens.

We describe the cloning and the evaluation of the protective capacity of 5 recombinant antigens expressed during the cysticercus stage of both Taenia crassiceps and Taenia solium. A cDNA library was constructed in bacteriophage lambda ZAP using mRNA isolated from larvae of T. crassiceps of the ORF strain. The recombinant phage library was screened with polyclonal antibodies against 56- and 74-kDa protective antigen fractions. This screening identified 13 recombinant clones, 5 of which were also strongly recognized by pooled sera from pigs experimentally infected with T. solium. The native antigens are proteins of 56 (clones KETcl, 4, 7) and 74 and 78 kDa (clones KETc11, 12) of T. crassiceps cysticerci. Vaccination experiments using these 5 recombinant clones against murine cysticercosis point to the relevance of KETcl, 4, 7, and 12 in host protection, whereas immunization with the clone KETc11 does not modify the parasite load in females and facilitates the parasitosis in males. We report here the DNA and the deduced amino acid sequence (100 amino acids) of the first protective antigen (KETc7) of potential interest for T. solium pig cysticercosis prevention.

Amino Acid Sequence↗
PubMed1996

[Clinical trial with tibolone in postmenopausal replacement therapy].

Estrogen deficiency is the basic change in women around the climateric stage. This hormone deficiency is different among women regarding the age and intensity of symptoms. The hormone replacement has proved its benefit on relieve of symptoms and long term effect on prevention of cardiovascular disease and osteoporosis. A new pharmacological agent Tibolona has been studied recently as replacement therapy. This work reports the results obtained with the use of Tibolona in 36 postmenopausal women. The effectiveness and security were confirmed as well as the low occurrence of side effects. It was also apparent that this therapy had a relevant effect on the psycho-emotional component and upon the improvement of sexual satisfaction and activity.

Adult↗
PubMed1995

Older children and adolescents living with perinatally acquired human immunodeficiency virus infection.

OBJECTIVE: To describe the clinical, immunologic, and psychosocial characteristics of children living with perinatally-acquired human immunodeficiency virus (HIV) infection beyond the age of 9 years. METHODS: This is a descriptive cohort study of 42 surviving perinatally infected children older than 9 years followed at the Children's Hospital Acquired Immunodeficiency Syndrome (AIDS) Program (part of a university-based inner city medical center) as of June 1993. The study is based on medical record data of clinical, immunologic, and psychosocial parameters. RESULTS: The cohort includes 20 boys and 22 girls with a mean age of 136 months. The mean age at diagnosis of HIV infection was 88 months, and 59.5% were asymptomatic at the time of diagnosis. Currently, after a mean follow-up period of 48 months from diagnosis, 23.8% remain asymptomatic, 19.1% have non-AIDS-defining HIV-related symptoms, and 57.1% have AIDS; 85.7% of the cohort did not develop HIV-related symptoms until after 48 months of age (late-onset prolonged survivors). There was an average annual decline of 71.4 CD4+ cells/microL in the cohort from the ages of 7 to 16 years, and 21.4% have a current CD4+ lymphocyte count of greater than 500 cells/microL, 28.6% between 200 and 500 cells/microL, and 50% less than 200 cells/microL; 76% are orphaned as a result of maternal death, with the majority of the cohort (60%) cared for by extended family members. Disclosure of diagnosis has occurred in 57.1%. The vast majority of the cohort (76%) are attending regular school, with the remainder in special education. CONCLUSIONS: Although close to one quarter of the children and adolescents ages 9 to 16 years living with perinatally acquired HIV infection described in this cohort remain asymptomatic and have a relatively intact immune system, the remainder are living with significant HIV-related symptoms, many of which are chronic in nature and have an impact on daily living. The children in this cohort had both significant immunologic deterioration and symptomatic disease progression during the mean follow-up period of 48 months from the time of diagnosis with HIV infection.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Determination of the poly(A) tail lengths of a single mRNA species in total hepatic RNA.

Poly(A) tail length is important in the stability and translation of mRNA. We describe procedures for the rapid and reproducible analysis of poly(A) tail length of a single mRNA species contained in a sample of total hepatic RNA. A short 3' fragment of a specific mRNA is prepared by RNase H digestion of the targeted mRNA region annealed to a short DNA oligonucleotide. The length of the poly(A) tail of the 3' fragment is then determined by running the sample on a polyacrylamide gel, by electrophoretic transfer, by probing with a radiolabeled cDNA and by comparing the size of the detected region with a specific RNA ladder or a DNA ladder.

Animals↗
PubMed1994

Characterization of monoclonal antibody PAM4 reactive with a pancreatic cancer mucin.

A monoclonal antibody (MAb), PAM4, having reactivity with pancreatic carcinoma has been developed. PAM4 is an IgG1 immunoglobulin produced by immunization of mice with mucin purified from the xenografted RIP1 human pancreatic carcinoma. An immunohistochemical study of normal adult tissues showed the PAM4 reactive epitope to be restricted to the gastrointestinal tract and absent from normal pancreas. In neoplastic tissue, PAM4 was reactive with 85% of the pancreatic carcinomas, approximately half of the colon cancers and none of the breast, ovarian, prostate, renal and liver cancers. PAM4 was, in general, non-reactive with pancreatitis specimens whereas CA19.9 and DUPAN2 were strongly reactive with each one. Treatment of the mucin antigen by heating, reduction of disulfide bonds, or protease digestion abolished immunoreactivity with PAM4. Treatment of the mucin by neuraminidase or periodate oxidation reduced immunoreactivity but did not completely abolish it. Our data are consistent with the proposal that the PAM4 epitope is a conformationally dependent peptide epitope and that certain carbohydrate structures are necessary in order to maintain the correct peptide conformation. The high specificity and intense reactivity of PAM4 with pancreatic carcinoma tissue suggests that the antibody may prove useful for in vitro diagnostic assays as well as in vivo targeting of diagnostic and therapeutic agents.

Adult↗
PubMed1994

Effects of television content on physical risk-taking in children.

This study is an investigation of effects of risk-taking by characters in television programs on children's self-reported willingness to take physical risks. Twenty-four boys and 26 girls, ages 6 to 9 years, were assigned to view TV stimulus programs with infrequent physical risk-taking. TV stimulus programs with frequent risk-taking, or no TV stimuli. A self-report measure was used to assess children's willingness to take physical risks in several common injury-relevant situations. Five of the items were administered as a pretest before children watched the stimulus programs and five items were used as a post-test after they viewed the programs. A validation assessment on an independent sample of children indicated that the risk-taking measure was positively correlated with other measures of risk-taking as well as physical injuries. Results indicated that children who viewed the high-risk TV programs increased their self-reported risk-taking significantly more than children in the low-risk TV and no-TV control conditions. Findings are discussed within a theoretical context of observational learning processes, with implications for childhood injury.

Analysis of Variance↗
PubMed1994

Estradiol receptors in combination with neu or myc oncogene amplifications might define new subtypes of breast cancer.

Amplifications of neu and c-myc were evaluated in 218 and 145 breast cancers (BC), respectively. Oncogene amplifications were determined for the most part by Southern blot. An association between the proportion of nodes affected and the intensity of neu amplification in estadiol receptor negative (ER-) BC was found (P = 0.028), which was confirmed by the multi-factor analysis of variance (P = 0.05). A significantly greater incidence in neu amplifications among BC with metastases was also found (P = 0.031). A strong association (P = 0.01) between the neu and myc amplification was observed. There is a strong association between myc amplification and ER- BC (P < 0.01). It is concluded that (1) the combination ER- with neu amplification might define a new group of more aggressive BC, as is suggested by their associated nodal involvement; (2) the linkage of myc amplifications with ER- BC and high grade of neu amplification might reflect a trait of tumor aggressivity.

Adult↗
PubMed1994

Sequence analysis of rice hoja blanca virus RNA 3.

RNA 3 of rice hoja blanca tenuivirus (RHBV) has 2299 nucleotides and resembles RNA 3 of other tenuiviruses such as maize stripe (MStV) and rice stripe (RStV) viruses in potentially coding with an ambisense strategy for two proteins. Both the viral-sense protein of 23K and the complementary-sense protein of 35K have about 46% amino acid identity with the analogous proteins encoded by RNA 3 of MStV and RStV. As the proteins of MStV and RStV have about 65% identity between themselves, RHBV cannot be a South and Central American strain of the Asian RStV. The intergenic region resembles those of other tenuiviruses, being rich in A and U residues, but its predicted folding pattern is unlike those of other tenuiviruses. Instead, the predicted folding of the intergenic region was indistinguishable from that of the coding regions and there was no evidence for a distinct hairpin-loop structure. The significance to the evolution of tenuiviruses of the similarities that the two proteins have with their analogues in other tenuiviruses is discussed.

Amino Acid Sequence↗
PubMed1994

Histological study in contralateral testis of prepubertal children following unilateral testicular torsion.

Histological changes in the contralateral testis in 8 prepubertal children whose ages ranged from 3 to 7.5 years with a history of testicular torsion and subsequent atrophy were studied. The following histological parameters were evaluated: fertility tubular index (FTI), Sertoli cell index (SCI) and minimum tubular diameter (MTD). According to our findings and following Nistal and Paniagua's classification (1984) for tubular alterations, we found 5 cases (62.5%) who present the following alterations. Type 1 (case 2): FTI was decreased above 50% corresponding to slight germinal hypoplasia with normal MTD and SCI. Type 2 (cases 3 and 5): testis with remarkable germinal hypoplasia; FTI was between 30 and 50% while MTD was below normal values. Type 3 (case 8): testis with diffuse tubular hypoplasia; FTI was below 30%, whereas MTD showed 33% decrease regarding normal values. Type 4 (case 6): testes with hyperplasia of Sertoli cells; SCI was increased one third with regard to that corresponding to his age; FTI showed severe hypoplasia of germ cells. No relationship between alterations in either the age of the patients or the time elapsed since the torsion was observed. Because of all these facts and the young age of our patients, we believe that the alterations found in the contralateral testis were due to congenital dysgenesia.

Atrophy↗
PubMed1994

Study of B and T cell phenotypes in blood from patients with common variable immunodeficiency (CVID).

B and T cell phenotypes in peripheral blood from 71 CVID patients have been measured in a study using directly conjugated monoclonal antibodies and two colour flow cytometry. Data was compared between different patient groups (based on whether their B cells could secrete IgM or IgG in vitro) and normal donors. There was a clear correlation between abnormalities of both B and T cells and the different patient groups. There were reduced absolute numbers of circulating CD4+ T cells, particularly those of the CD4+.CD45RA+ subset, and of CD19+ B cells in those patients whose B cells failed to secrete IgM or IgG in vitro. This demonstrates an association between B cell lymphopenia, failure of B cell immunoglobulin production in vitro and T cell subset lymphopenia in CVID. It supports the view that this group of CVID patients has a disease involving T cell regulation of B cells of varying severity.

Antibodies, Monoclonal↗
PubMed1994

Herpes simplex pneumonia in a young immunocompetent man.

We report the case of a 33 year old man with herpetic bronchitis and bilateral pneumonitis. He presented without mucocutaneous lesions, and his cellular and humoral immunity were not compromised. Diagnosis was established on histological and cytological findings and confirmed by serology. Acyclovir treatment led to a favourable outcome.

Acyclovir↗
PubMed1994

Neonatal mixed lineage acute leukaemia.

We report here an uncommon case of neonatal acute leukaemia that presented concomitant with serological evidence of rubella infection. The clinical course was aggressive and the patient died 5 days after diagnosis from septicaemia. Leukaemic blasts had a mixed lineage immunophenotype co-expressing a constellation of B-lymphoid (CD19, cytCD22, TdT) and myeloid (CD13, CD33, CD14, anti-MPO) markers, as well as multiple adhesion molecules and markers associated with early lympho-myeloid progenitor cells (CD34, CD7, HLA-DR). A previously unrecorded discordant expression of different CD10 and CD34 epitopes was identified using different monoclonal antibodies. The karyotype was 46,XX t(4;11)(q21;q23) and molecular analysis confirmed rearrangement of the trithorax-related oncogene HRX at 11q23. There was a clonal biallelic rearrangement of the immunoglobulin heavy-chain gene. The features of this rare case have implications for possible aetiological events leading to leukaemia.

Acute Disease↗
PubMed1993

Catecholaminergic innervation of the equine ureter.

The aim of the present study was to determine the distribution and density of catecholaminergic nerve fibres and cells in the equine ureter by using immunohistochemical techniques to localise the enzyme tyrosine-hydroxylase (TH). TH-immunoreactive (TH-IR) nerve fibres entered the wall of the ureter as adventitial nerve trunks accompanying the blood vessels. These trunks repeatedly branched as they coursed through the muscular layer towards the epithelium, forming muscular, perivascular and subepithelial nerve plexuses. TH-IR nerve fibres were especially numerous in the pelvic and intravesical ends of the ureter. TH-IR cells have also been identified in the equine ureteral wall, usually grouped as adventitial and intramural nerve ganglia. The results of the present study demonstrated that the equine ureter, like that of other mammals, possesses a rich autonomic supply of catecholaminergic (TH-IR) nerve fibres. These morphological data support a role for the autonomic nervous system in the control of ureteral peristalsis.

Animals↗
PubMed1993

Diminished DNA synthesis in T cells from B chronic lymphocytic leukemia after phytohemagglutinin, anti-CD3, and phorbol myristate acetate mitogenic signals.

T lymphocytes from patients with B cell chronic lymphocytic leukemia (B-CLL) exhibit defective proliferative response to plant lectins. The blastogenic response of purified T lymphocytes to signals that interact with membrane molecules (phytohemagglutinin [PHA], anti-CD3 monoclonal antibody [MAB]) and with the intracytoplasmic protein kinase C (PKC) was investigated in 22 B-CLL patients and 18 healthy controls. 3H-thymidine uptake in T lymphocytes from 14 of 22 B-CLL patients after PHA, anti-CD3, and phorbol myristate acetate (PMA) was found to be lower than in the healthy controls. This defective proliferative response was not corrected by the exogenous addition of interleukin-2 (IL-2) to the culture medium. In analyzing the cell cycle progression of these T lymphocytes from B-CLL patients, we found that the percentage of cells in S phase at 2 days of PHA stimulation was significantly decreased and that it was normalized after 5 days of culture. Defective response of T lymphocytes from B-CLL patients to polyclonal mitogens was observed in those patients with advanced disease (stages A, B, and C). However, this T cell proliferative response was normal in patients with "smoldering B-CLL." We conclude that the defective proliferative response to membrane and intracytoplasmatic mitogenic signals on T lymphocytes from a part of B-CLL patients can be ascribed to delayed activation and cell-cycle progression, and an association between the alterations in the T cell compartment of B-CLL patients and the progression of the disease may be suggested.

Aged↗