Search PubMed⌕ Search

Biomedical subjects

M Valle

Publications and source records attributed to M Valle.

At least 19 recordsLinked to original sources
PubMed1996

Acute and chronic changes in atrial natriuretic factor induced by ventricular pacing: a self controlled clinical trial.

A self controlled clinical trial was carried out to study the acute and chronic effects of ventricular pacing (VVI) on the atrial natriuretic factor (ANF). Eleven people were selected from a pool of 20 DDD paced patients. Pacemakers were programmed to the VVI mode for 1 month and their effectiveness tested by ECG at rest and after an effort test. AnF was measured by radioimmunoassay at baseline, after 15 minutes, and again 1 month after programming. The reliability of the radioimmunoassay was confirmed using the coefficients of variation between (12.5%) and within assay (9.7%). Data analysis was done using Wilcoxon's test. Our results showed that the onset of VVI pacing led to a sudden sharp rise in ANF in all patients (P < 0.0001). During VVI pacing, three patients were dropped from the study (2 were withdrawn because of symptoms and 1 voluntarily withdrew). After 1 month of VVI pacing, a significant increase of ANF above the baseline was observed (P < 0.05). The results showed that ventricular pacing led to an immediate rise in ANF and, that with long-term VVI pacing, there was an increase in ANF levels as well. The role of these findings in the pathophysiology of the pacemaker syndrome calls for further research.

Adult↗
PubMed1995

A new case of trisomy 5 as sole cytogenetic anomaly in acute myeloid leukemia.

We present a case of acute myeloid leukemia (AML-M2) with trisomy 5 (+5) as the sole cytogenetic abnormality in a woman previously diagnosed with schizophrenia. To date, only two cases of AML (other than M2) with +5 as the only change have been reported. Moreover, an association between schizophrenia and partial trisomy of chromosome 5p has been described recently. To our knowledge, this is the first report of AML (subtype-M2) with +5. Noteworthy is the association with schizophrenia.

Chromosomes, Human, Pair 5↗
PubMed1995

Plasma pancreastatin-like immunoreactivity correlates with plasma norepinephrine levels in essential hypertension.

Pancreastatin (PST), a 49 amino acid peptide originally isolated from porcine pancreas, is derived from chromogranin A (Cg A), an acidic protein co-released with catecholamines from sympathetic nerve terminals and chromaffin cells. Extracellular processing of Cg A yields PST as well as other biological active peptides. Measurement of Cg A and PST-like immunoreactivity (PST-LI) has been used to investigate patients with pheochromocytoma and other neuroendocrine neoplasia. Some studies have found increased plasma norepinephrine (NE) levels in essential hypertension. We therefore measured venous plasma PST-LI and catecholamines in patients with essential hypertension. We employed a radioimmunoassay developed with commercially available reagents for measuring plasma PST-like immunoreactivity, and HPLC with electrochemical detection for measurement of plasma catecholamines. The correlation of PST-LI with epinephrine (E) was very weak. However, its correlation with NE was highly significant. Thus, venous plasma PST-LI immunoreactivity may reflect sympathetic nerve activity in essential hypertension.

Adult↗
PubMed1995

Influenza vaccination in 18 developed countries, 1980-1992.

Influenza continues to be an important cause of preventable morbidity and mortality. Although influenza vaccine is widely recommended for older high-risk individuals, no studies have compared its use in different countries. We gathered information on influenza vaccine distribution in 18 developed countries for the period 1980-1992. During the 1980s there was a > or = 10-fold difference in annual per capita vaccine distribution among these countries, and in 1992 the difference was still more than 7-fold. Several countries demonstrated large increases in vaccine use over the study period, some showing substantial increases in specific years. Thirteen of the 18 countries recommend influenza vaccination for all elderly persons and 11 countries provide reimbursement for vaccination through national or social health insurance. These countries tend to have higher levels of vaccine use. Historical, economic and political factors also affect vaccination practices and policies, but their relationships to differences in vaccine use between countries are not known. A better understanding of why the use of influenza vaccine varies among countries will be important if its protective benefits are to be fully realized.

Developing Countries↗
PubMed1995

Persistence of anti-mumps virus antibodies after a two-dose MMR vaccination. A nine-year follow-up.

A two-dose vaccination program against measles, mumps, and rubella (MMR) viruses was started in Finland in 1982. In this program the trivalent MMR-II vaccine (MSD, USA) was offered to children at the ages of 14-18 months and 6 years followed by revaccination 4-5 years later. The vaccination coverage has been high (97%) and MMR infections have practically been eliminated in the Finnish population. In a serological follow-up program sequential serum samples were obtained from 254 children (127 14-18-month-old vaccinees and 127 6-year-old vaccinees) during a 9-year follow-up period. Anti-mumps virus antibody titers were determined by enzyme immunoassay using purified whole mumps viruses as the antigen. In seronegative (n = 120) 14-18-month-old vaccinees the seroconversion rate was 86% (geometric mean titer 1/1670 +/- 1/270). The antibody levels fell rapidly (significance p < 0.01) within the first year of follow-up (mean titer 1/1080 +/- 1/190), but remained relatively stable in subsequent years. After revaccination the seropositivity rate was 95% (mean titer 1/2310 +/- 1/260) and declined more slowly thereafter to 86% (mean titer 1/1510 +/- 1/210) at year 9 of follow-up. The mean antibody titer was significantly (p < 0.05) higher 4 years after the second MMR vaccination when compared with the corresponding time point after the first vaccination. In 6-year-old seronegative vaccinees the increase and decay of anti-mumps virus antibodies after the first MMR vaccination was similar to that seen in the group of younger vaccinees. A two-dose MMR vaccination protocol resulted in a high mumps immunity level in the vaccinated population.

Age Factors↗
PubMed1995

Impaired response to hepatitis B vaccine in children receiving anticancer chemotherapy.

Serologic responses to hepatitis B vaccine were investigated in 197 pediatric cancer patients. The patients, ages 1 to 21 years, comprised 66 with solid tumors, 101 with hematologic malignancies and 30 with various benign conditions. Of them 51 were receiving cytotoxic chemotherapy and 114 had not received chemotherapy for 0.2 to 11 years. Three doses of plasma-derived hepatitis B vaccine (20 micrograms) were given at 0, 1 and 6 months; and antibody concentrations to hepatitis B surface antigen were determined at 3, 6 and 8 months. The geometric mean antibody concentration after 3 vaccine doses was 1076 mIU/ml in cancer patients receiving chemotherapy and 18,833 mIU/ml in cancer patients not receiving chemotherapy. The protective titer of antibody (> or = 10 mIU/ml) was reached after 3 doses of vaccine by 67% of patients receiving chemotherapy and by 97% of those not receiving chemotherapy. The patients being treated for solid tumors had weaker responses than those being treated for hematologic malignancies: after 3 vaccine doses no response was observed in 6 of 11 patients with solid tumors compared with 3 of 25 of patients with hematologic malignancies. Children receiving anticancer chemotherapy have essentially weaker responses to hepatitis B vaccine than children not receiving chemotherapy or those with benign conditions. This reflects the profound immunosuppression during chemotherapy. The effect of more intensive immunization schedules should be investigated.

Adolescent↗
PubMed1995

Evidence of feline immunodeficiency virus replication in cultured Kupffer cells.

OBJECTIVE: To determine if cultured feline Kupffer cells (KC) are as permissive for feline immunodeficiency virus (FIV) as cultured human liver macrophages are for HIV. Two types of infection likely to be relevant to the in vivo situation were used. KC were infected with either free virus or autologous infected peripheral blood mononuclear cells (PBMC). METHODS: Feline KC were isolated by centrifugal elutriation from collagenase-perfused liver; cultured cells were characterized by their morphological appearance and their erythrophagocytotic properties. After infection, viral replication was measured by enzyme-linked immunosorbent assay, reverse transcriptase activity, immunofluorescence assay, in situ hybridization and electron microscopic observations. RESULTS: Three days after isolation, 85% of cultured KC were able to internalize red blood cells; 45% were CD4-positive and 65% expressed a 24 kD protein thought to be a receptor for FIV (CD9). After the addition of autologous infected PBMC or cell-free supernatant of chronically infected IRC4 cells to KC cultures, a peak of viral replication was detected at day 28. Antigen revealed by immunofluorescence assay was present in only 0.4%, and viral RNA was detected by in situ hybridization in 2% of the infected cells. CONCLUSIONS: FIV can replicate in cultured feline KC without inducing any cytopathic effect, which suggests that these cells may play a role in the physiopathology of FIV infection.

Animals↗
PubMed1995

Increased plasma pancreastatin-like immunoreactivity levels in non-obese patients with essential hypertension.

DESIGN: Pancreastatin, a novel peptide, is known to inhibit insulin secretion and to have a glycogenolytic effect, and is present in many endocrine and chromaffin cells. Both the plasma insulin levels and the adrenergic activity accompanying insulin resistance have been shown to be increased in hypertensive subjects. Our working hypothesis was that pancreastatin might play a role in these pathological phenomena. METHODS: We studied the plasma pancreastatin level in non-obese essential hypertensive patients in response to an intravenous glucose load. We further measured the responses to the glucose challenge of insulin, glucagon, catecholamines and free fatty acids, as well as other factors related to insulin resistance (i.e. lipoproteins and apolipoproteins). We separated the hypertensive patients into three groups according to their response to an oral glucose-tolerance test: normoinsulinaemic, hyperinsulinaemic and glucose-intolerant. Matched normotensive control subjects were also studied. RESULTS: Pancreastatin levels did not change in the control group after the glucose challenge. However, all hypertensive patients showed an increase in plasma pancreastatin levels after glucose loading. The normoinsulinaemic hypertensive patients also had elevated basal pancreastatin levels. The increase in pancreastatin levels was in the ranking: normoinsulinaemic > hyperinsulinaemic > glucose-intolerant. The pancreastatin: insulin ratio showed that the secretion of pancreastatin and insulin may be regulated differently. Basal free fatty acid and glucagon levels were found to be elevated both in the hyperinsulinaemic and in the glucose-intolerant group. Fasting triglycerides levels were increased in all of the hypertensive patients. Other risk factors for coronary artery disease were also found to be altered: elevated very low-density lipoprotein-cholesterol and decreased high-density lipoprotein-cholesterol, with ranking: normoinsulinaemic < hyperinsulinaemic < glucose-intolerant. CONCLUSIONS: These results show an increase in pancreastatin levels in hypertensive patients, suggesting that pancreastatin might play a role in the pathophysiology of essential hypertension.

Adult↗
PubMed1995

Mouse hepatitis virus type 3 infection provokes a decrease in the number of sinusoidal endothelial cell fenestrae both in vivo and in vitro.

Fenestrations of hepatic endothelial cells play an active role as a sieving barrier allowing extensive exchange between the blood and liver parenchyma. Alteration of these structures may be induced in the course of various pathological events and provoke important perturbations of liver function. We demonstrate here that sinusoidal endothelial cells are permissive for mouse hepatitis virus 3 (MHV3) in vivo and in vitro and that this infection leads to a striking decrease in the number of fenestrae. The disappearance of these structures observed under scanning electron microscopy or in cryofracture preparations in vivo and in vitro cannot be reversed by the action of cytochalasin B on the microfilament network. The decrease in the porosity seems to be related directly to the productive infection of the endothelial cells, because it was not observed in A/J mice resistant to the virus and in susceptible BALB/c mice immunized with a thermosensitive mutant in which no viral replication occurs. In conclusion, a viral infection of liver endothelial cells may cause extensive loss of the fenestrations and thus lead to important functional pertubations.

Animals↗
PubMed1995

[Complex perianal fistula: diagnosis and treatment].

After a detailed discussion of the question of perianal fistulas, the authors use their own experience to examine complex perianal fistulas (trans-sphincteric with involvement of the puborectal muscle, high intersphincteric, extrasphincteric and supersphincteric) which represent 5-15% of cases. They affirm that elective treatment consists of surgical silk to ensure the optimal drainage of the fistula and provoke sclerosis of adjacent tissues, followed after 9 weeks by either the slow section of the fistula using a silicone ligature or direct fistulotomy. No cases of incontinence or recidivation were observed using this method in 29 cases treated between 1990 and 1992 who were followed up for between 6-24 months.

Anus Diseases↗
PubMed1994

The elimination of indigenous measles, mumps, and rubella from Finland by a 12-year, two-dose vaccination program.

BACKGROUND: In the 1970s measles, mumps, and rubella were rampant in Finland, and rates of immunization were inadequate. In 1982 a comprehensive national vaccination program began in which two doses of a combined live-virus vaccine were used. METHODS: Public health nurses at 1036 child health centers administered the vaccine to children at 14 to 18 months of age and again at 6 years, and also to selected groups of older children and young adults. Vaccination was voluntary and free of charge. In follow-up studies, we focused on rates of vaccination, reasons for noncompliance, adverse reactions, immunogenicity, persistence of antibody, and incidence of the three diseases. Since 1987, paired serum samples have been collected from all patients with suspected cases of measles, mumps, or rubella. RESULTS: Over a period of 12 years, 1.5 million of the 5 million people in Finland were vaccinated. Coverage now exceeds 95 percent. The vaccine was efficient and safe, even in those with a history of severe allergy. No deaths or persistent sequelae were attributable to vaccination. The most frequent complication requiring hospitalization was acute thrombocytopenic purpura, which occurred at a rate of 3.3 per 100,000 vaccinated persons. The 99 percent decrease in the incidence of the three diseases was accompanied by an increasing rate of false positive clinical diagnoses. In 655 vaccinated patients with clinically diagnosed disease, serologic studies confirmed the presence of measles in only 0.8 percent, mumps in 2.0 percent, and rubella in 1.2 percent. The few localized outbreaks were confined to patients in the partially vaccinated age groups. There are now fewer than 30 sporadic cases of each of the three diseases per year, and those are probably imported. CONCLUSIONS: Over a 12-year period, an immunization program using two doses of combined live-virus vaccine has eliminated indigenous measles, mumps, and rubella from Finland. Serologic studies show that most reported sporadic cases are now due to other causes, but a continued high rate of vaccination coverage is essential to prevent outbreaks resulting from exposure to imported disease.

Child↗
PubMed1994

Diminished insulin receptors on erythrocyte ghosts in nonobese patients with essential hypertension independent of hyperinsulinemia.

Hypertension is associated with insulin resistance and dyslipidemia in a syndrome named X. Epidemiologic evidence also supports a link between hyperinsulinemia and blood pressure (BP), independent of obesity and non-insulin-dependent diabetes mellitus. To assess the possible role of insulin receptors in this syndrome, we studied insulin binding by erythrocyte ghosts in patients with moderate essential hypertension with or without fasting or postglucose hyperinsulinemia. We measured plasma glucose and insulin before and at 30, 60, and 120 min after administration of 75 g glucose in 62 hypertensive patients and 20 matched normotensive controls. Both groups had comparable age (mean 45 years) and waist/hip ratios (mean 0.88). Patients undergoing antihypertensive treatment did not receive antihypertensive medication for 3 weeks. Patients with fasting or postglucose hyperglycemia were excluded from the study. Insulin binding to erythrocyte ghosts was significantly decreased (p < 0.001) to almost half the values of controls (6.5% specific binding) in both patients with hyperinsulinemic (3.2% specific binding) and those with normoinsulinemic (3.9% specific binding) hypertension. Scatchard analysis demonstrated that this was due to a lesser number of insulin receptors. These data indicate that patients with essential hypertension can show decreased erythrocyte insulin receptors without detectable hyperinsulinemia.

Adult↗
PubMed1994

Receptors for pancreastatin in rat liver membranes: molecular identification and characterization by covalent cross-linking.

High affinity binding sites for pancreastatin were identified for the first time, and their molecular characterization was performed with rat liver membranes. Using rat 125I-pancreastatin, we have studied the interaction of pancreastatin with liver membranes. Cross-linking of the tracer to the membranes was performed using the bifunctional reagent dithiobis(succinimidyl propionate). Analysis of binding under equilibrium conditions indicated the existence of one class of binding sites, with a Bmax of 15 fmol/mg of protein and an apparent Kd of 0.2 nM. The cross-linking of 125I-pancreastatin to liver membranes revealed a single band of M(r) 40,000, corresponding to the 125I-pancreastatin-receptor complex. The labeling of this complex was inhibited in the presence of rat pancreastatin (10(-10) to 10(-7) M) and in the presence of guanyl-5'-ylimidodiphosphate (10(-7) to 10(-4) M). Pretreatment of rat liver membranes with pertussis toxin did not affect pancreastatin binding or the inhibition by guanyl-5'-ylimidodiphosphate of pancreastatin binding. The specificity of pancreastatin binding was further assessed by displacement experiments with pancreastatin from other species and vasopressin. The binding of the pancreastatin-receptor complexes to Sepharose coupled to different lectins showed the glycoprotein nature of the pancreastatin receptor. These results strongly suggest that rat liver possesses a specific pancreastatin receptor, a glycoprotein of M(r) 35,000 that is coupled to a pertussis toxin-insensitive G protein in the plasma membrane.

Animals↗
PubMed1992

HIV-induced deletion of antigen-specific T cell function is MHC restricted.

When antigen-specific T cells are pulsed by antigen-presenting cells (APC) in the presence of HIV they are functionally deleted following subsequent exposure to syngeneic APC in the absence of HIV. Recombinant soluble HIV envelope (gp120) is able to induce a similar effect which, unlike that induced by HIV, is reversible. Neither HIV nor gp120 affect the ability to respond to IL-2. Thus it is only antigen-specific responses involving the T cell receptor pathways and CD4/MHC class II interaction that appear to be inhibited by HIV-1 and gp120. Furthermore, the functional impairment caused by HIV-1 is specific to the T cells that respond to the antigen in co-culture with HIV, as there is no apparent effect on 'bystander'-activated T cells specific for another antigen. Antigen-specific T cell lines may be deleted by a signalling mechanism which involves molecules other than gp120/CD4 but still requires MHC class II restriction.

Animals↗
PubMed1992

Lipoproteins and their genetic variation in subjects with and without angiographically verified coronary artery disease.

To examine the concentration of serum lipoproteins and the association of their genetic variation with the occurrence of coronary artery disease (CAD), composite serum lipoprotein profiles including lipoprotein(a) (Lp[a]), apolipoprotein (apo) E phenotypes, and apo B Xba I genotypes were determined in patients with angiographically verified CAD (CAD+ group, n = 111) and in subjects with no angiographic evidence of CAD (CAD- group, n = 46). In addition, we determined the concentrations of serum lipids, lipoproteins, and apolipoproteins in 96 healthy controls. Both CAD- and CAD+ groups had lower concentrations of apos A-I and A-II but higher concentrations of serum total and very low density lipoprotein triglyceride and very low density lipoprotein cholesterol than did healthy controls. The mean concentrations of serum total and low density lipoprotein cholesterol and the median values of Lp(a) were similar in the CAD+ and CAD- groups, both having higher concentrations of low density lipoprotein cholesterol and apo B than the healthy controls. Irrespective of gender, patients with CAD had significantly lower serum high density lipoprotein cholesterol than did those without CAD (1.48 +/- 0.40 versus 1.16 +/- 0.29 mmol/l, p less than 0.001). In women, the mean serum total and very low density lipoprotein triglyceride concentration was also higher in the CAD+ than in the CAD- group. The frequency of the apo E4 allele (epsilon 4) was significantly higher in the CAD+ group (0.293) than in the CAD- group (0.174; p less than 0.001). The frequencies of the two apo B alleles, X1 (Xba I restriction site absent) and X2 (Xba I restriction site present), were similar in the two groups. Stepwise discriminant analysis revealed that in men, serum high density lipoprotein cholesterol had the highest power to discriminate for CAD. In addition, the concentration of plasma apo B levels and the occurrence of apo E phenotypes were independently associated with CAD in men. In women, the only independent factor associated with CAD after adjustment for beta-blocker and diuretics usage was the concentration of serum triglycerides.

Adult↗
PubMed1992

[Complications of hepatic hydatidosis].

Fifty cases of complicated hydatid cyst of the liver on a total of 250 cases of hydatid cyst observed were analyzed. The Authors describe the several complications observed (compression, infection, rupture into biliary tract or into the thorax or into the peritoneal cavity, the diagnostic and therapeutic procedures. Total mortality was about 7.6% (3 cases) 2 patient died for intraperitoneal rupture and one for rupture in the biliary tract. Surgical treatment should be as radical as possible performing total or subtotal pericystectomy, hepatic resection is reserved to selected cases. Drainage by Kehr tube of biliary tract is necessary of rupture of the cyst in the biliary tract, while we limit the indication for a papillostomy to the sphincter duct stenosis.

Adult↗