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Biomedical subjects

J Bosch

Publications and source records attributed to J Bosch.

At least 127 records · Page 7Linked to original sources
PubMed1998

Immunoreactive osteocalcin forms in conditioned media from human osteoblast culture and in sera from healthy adult control subjects and patients with bone pathologies.

BACKGROUND: The aim of this work was to study the immunoreactive forms of bone Gla protein (BGP) present in conditioned media of human osteoblast cultures (BGP released from osteoblast) and in the sera of healthy adult control subjects and patients with bone pathologies (chronic renal failure on haemodialysis, Paget's disease of bone and post-menopausal osteoporosis). METHODS: The technical procedure used was a combination of high-performance liquid chromatography (HPLC) and different BGP assays with several specificities to analyse BGP levels in the different HPLC fractions. Aliquots of conditioned media or sera were purified through a Sephadex G-50m column and by HPLC (C4 reverse-phase column) in a 25-40% acetonitrile gradient. Two-minute fractions were collected and divided into three aliquots in order to determine osteocalcin content using three different assays: (a) ELSA-OST-NAT IRMA, which only detects intact osteocalcin; (b) ELSA-OSTEO IRMA, which detects intact osteocalcin and N-terminal fragments; and (c) OSCA Test RIA, which detects intact osteocalcin, C-terminal and other fragments. RESULTS: We found different immunoreactive forms of osteocalcin in the culture medium of human osteoblasts and in sera from control subjects and patients for the bone pathologies studied. We did not find great qualitative differences between the immunoreactive osteocalcin profile found in the culture medium from human osteoblasts and the sera from healthy control subjects. However, the different bone pathologies show different characteristic patterns of immunoreactive forms of osteocalcin. CONCLUSIONS: An interesting finding has been the detection, both in sera and in osteoblast culture media, of several immunoreactive forms of intact osteocalcin that eluted from HPLC at different acetonitrile percentages, and therefore correspond to different molecular forms.

Adult↗
PubMed1998

Preparation and characterization of differently aggregated colorectal carcinoma cell subpopulations from surgical specimens.

The loss of intercellular adhesion within the primary tumor is one of the key events leading to metastasis. Although a number of adhesion molecules involved in intercellular adhesion have been described in experimental systems, the clinical relevance of many of these molecules still has to be determined. We tried to assess the contribution of membrane-bound carbohydrates and of E-Cadherin, CEA, and Sia-LeA for intercellular adhesion of cells isolated from colorectal carcinoma tissue directly obtained from the surgeon. A subpopulation of nonaggregating cells was prepared by means of slowly passing of freshly isolated cells through a series of sieves with decreasing mesh widths. Nonaggregating cells differed mainly in two aspects from aggregated cells: (i) determination of lectin binding and of specific sialytransferase activities revealed enhanced alpha2,6-sialylation of nonaggregating cells, and (ii) staining with specific antibodies documented a loss of E-Cadherin reactivity of such cells. An enhanced activity of beta-galactoside alpha2,6-sialytransferase (ST6Gal 1) was found in metastasizing colorectal carcinomas; however, its biological function has to be shown. Our results suggest that ST6Gal 1 is responsible for reduced homotypic aggregation of colorectal carcinoma cells and may thus facilitate the release of single cells from the primary tumor.

Agglutinins↗
PubMed1998

Perinatal listeriosis: a population-based multicenter study in Barcelona, Spain (1990-1996).

The aim off this study was to describe the incidence, epidemiology, clinical presentation, and outcome of perinatal listeriosis for a 7-year period (1990-1996) based on data of an active population-based surveillance project implemented in the city of Barcelona, Spain. There were 30 cases (20.8%) associated with pregnancy (15 pregnant women, 13 neonates, and 2 fetal deaths). The incidence of perinatal listeriosis varied from 4.1 to 0 per 10,000 live births. The proportion of perinatal cases in relation to the total number of cases of listeriosis varied between 0 and 42%. Early-onset neonatal sepsis accounted for 12 of 13 live births. The mean age of infected pregnant women with listeriosis was 30.1+/-2.0 years. Chorioamnionitis was the predominant clinical form (86.7%). Only two mothers had primary bacteremia by L. monocytogenes in the second trimester of pregnancy. Both infants were born healthy, without signs of infection. One of these mothers was infected with the human immunodeficiency virus (HIV). Since January 1994, 12 strains were available for serotyping and phagotyping; 9 belonged to serovar 4b, 2 to serovar 1/2b, and 1 to serovar 1/2a. No outbreaks of L. monocytogenes infection occurred during the study period. The overall neonatal mortality rate was 7.7% among infected live births. All pregnant women were treated with ampicillin and none died. Early antenatal treatment with ampicillin improves neonatal outcome and can result in the birth of healthy babies.

Adult↗
PubMed1998

Development of analogues: successes and failures.

The search for new pharmaceutical treatments has led to the isolation of products from a range of natural sources. Analogues synthesized from these products may possess an improved therapeutic effect over their natural counterparts. Two natural peptides, vasopressin and somatostatin, possess pronounced in vivo effects, so do their analogues terlipressin and octreotide. Vasopressin is a powerful vasopressor, reducing portal pressure, and has been used to treat gastrointestinal haemorrhages. However, a number of adverse cardiovascular effects resulting from an increase in peripheral vascular resistance have been associated with this drug. Terlipressin, however, is more effective, has an improved safety profile and is associated with fewer side effects than vasopressin. Somatostatin, a growth regulatory hormone, achieves haemostasis by decreasing splanchnic blood flow, and is effective in preventing early rebleeding. Somatostatin is effective in treating bleeding oesophageal varices (BOV) and is associated with fewer and more transient side effects than terlipressin. Octreotide, however, has greater stability and a longer half-life than somatostatin, but has a less favourable safety profile. Octreotide displays a number of therapeutic advantages over somatostatin, but not in the treatment of gastrointestinal indications. The development of terlipressin from vasopressin has demonstrated a number of clinical advantages, while the development of octreotide from somatostatin has not shown any significant advantage in the treatment of BOV.

Esophageal and Gastric Varices↗
PubMed1998

Medical treatment of portal hypertension.

The medical treatment of portal hypertension has experienced marked progress in the past decade due to the production of effective portal hypertension therapy. This has been possible because of the better understanding of the pathophysiological mechanisms leading to portal hypertension. A major step forward was the introduction of beta-blockers for the prevention of bleeding and rebleeding from gastroesophageal varices. Effective therapy requires the reduction of the hepatic venous pressure gradient (HVPG) to 12 mm Hg or below, or at least by 20% of baseline values. Unfortunately, this is only achieved in 1/3-1/2 of patients. The combination therapy associated with isosorbide-5-mononitrate and propranolol or nadolol administration enhances the fall in portal pressure and increases the number of patients in whom HVPG decreases more than 20% and below 12 mm Hg. Randomized trials (RCTs) support the fact that combination therapy is more effective than propranolol or nadolol alone and better than sclerotherapy. In the treatment of acute variceal bleeding, pharmalogical therapy offers the unique advantage of permitting the provision of specific therapy immediately after arrival to hospital, or even during transferral to hospital by ambulance, since it does not require sophisticated personnel. Terlipressin has proved to be effective and to decrease mortality from bleeding. RCTs have shown that this drug is as effective and safer than emergency sclerotherapy. Therapy should be maintained for five days to prevent early rebleeding. Somatostatin is probably as effective as terlipressin.

Adrenergic beta-Antagonists↗
PubMed1998

Acute delirium as a manifestation of obstructive sleep apnea syndrome.

Cognitive deficits and psychiatric manifestations such as depression and psychosis have been associated with obstructive sleep apnea (OSA) syndrome. We report a patient with OSA admitted to our center because of acute delirium of sudden onset at night, during sleep, and which impelled the patient to jump out of the window of his home. After exhaustive study, no other causes were found for the delirium, which resolved when nasal continuous positive airway pressure (nCPAP) was initiated. We believe that it is clinically important to be aware of this association, since it identifies a new, treatable cause of delirium.

Acute Disease↗
PubMed1998

[Parkinsonian hemi-syndrome as the initial manifestation of supratentorial cystic hemangioblastoma in a patient with Von Hippel-Lindau disease].

INTRODUCTION: Retino-cerebellar hemangioblastomatosis or Von Hippel-Lindau (VHL) disease is a phacomatosis with a dominant autosomal pattern of inheritance, which is characterized by the presence of hemangioblastomas of the central nervous system (cerebellum and spinal medulla), retinal angiomas and tumors (pheochromocytoma, clear cell carcinoma) or cysts of the abdominal viscera. CLINICAL CASE: We present the case of a 22 year old female with Von Hippel-Lindau disease, in whom a cystic hemangioblastoma of the basal ganglia of the left hemisphere was diagnosed when she complained of difficulty in carrying out fine movements of the right hand and tremor for some months. The supratenorial site of cystic hemangioblastomas in the clinical context of Von Hippel-Lindau disease is very rare and clinical presentation of a parkinsonian hemisyndrome is exceptional. In our search through the literature we have found tumors with many types of histology (meningiomas, glial tumors, craniopharyngioma, epidermoid cysts) in the origin of tumoral parkinsonism. CONCLUSIONS: However, we have found no previous case of cystic hemangioblastomas. We also emphasize that there was full resolution of the condition after total removal of the tumour.

Adult↗
PubMed1998

[The usefulness of a selective disk-broth media for the detection of group B streptococci in the vagina].

BACKGROUND: The detection of pregnant group B streptococci (GBS) carriers allows intrapartum administration of antibiotic prophylaxis to these women and prevents perinatal infection by this microorganism. The aim of this study was to determine the usefulness of a selective media to detect GBS in the vagina based on the disk-broth method. MATERIAL AND METHODS: One thousand six hundred five vaginal swabs were seeded in blood agar with colistin and nalidixic acid (NDA) and in a selective disk-broth tube consisting of 2 ml of Mueller-Hinton broth with 5% serum and a disk of 30 micrograms of amikacin which was reseeded at 24 hours of incubation in blood agar with NDA. RESULTS: GBS was isolated by either of the two methods in 209 samples (13.0%); in 160 (9.9%) in the initial dish of blood agar with NDA and in 205 (12.7%) in the subculture of the selective disk-broth media. CONCLUSIONS: The selective disk-broth media used in this study is a simple method which allows detection of GBS in vaginal samples of women with GBS cultures in a negative agar blood dish.

Adult↗
PubMed1998

[Value of cranial MRI in the follow-up of dural sinus thrombosis].

INTRODUCTION: At the present time it is well established that cranial magnetic resonance (MR) is the imaging technique of choice for diagnosis of thrombosis of the dural sinuses. However, few studies have been done to evaluate its role in follow-up in this cerebrovascular disorder. OBJECTIVE: To assess the alterations in resonance signal in follow-up of patients with thrombosis of the dural sinuses and the clinical correlation of this. MATERIAL AND METHODS: We reviewed the clinical histories of 12 patients diagnosed on cranial MR as having thrombosis of the dural sinuses; 8 cases were also seen again six months later. The cranial MR study was done using a 1.5 or 1.0 T superconductive apparatus to do measured spin-echo sequences (SE) in T1 and T2 in sagittal, transverse and coronal planes. The time elapsed between diagnosis on MR and clinical diagnosis was between 24 hours and 6 months. RESULTS: All patients had stronger resonance signals in T1 and T2 indicating a subacute phase of the thrombosis (oxidative conversion of deoxyhaemoglobin to methoxyhaemoglobin) and complete absence of blood flow in the sinuses. The eight patients seen again after six months were found to be normal on neurological. On cranial MR partial recanalization was seen in 5 of these (62%). CONCLUSION: Changes in the resonance signal persist for a long time both with and without signs of recanalization. This finding does not affect the medium term clinical course.

Adult↗
PubMed1998

The Study of Health Assessment and Risk in Ethnic groups (SHARE): rationale and design. The SHARE Investigators.

The Study of Health Assessment and Risk in Ethnic groups (SHARE) is a study to determine the risk factors for atherosclerosis among three ethnic populations in Canada. Three hundred and thirty South Asian Canadian, 320 Chinese Canadian and 320 European Canadian men and women between 35 and 75 years of age are being randomly sampled from communities in Hamilton and Toronto, Ontario and Edmonton, Alberta for assessment of conventional (i.e., smoking, dyslipidemia, diabetes and hypertension) and emerging (i.e., candidate genes for atherosclerosis, homocysteine, fibrinolytic parameters, neurohormones, glucose intolerance, markers of infection, socioeconomic status, psychosocial status and diet) cardiovascular disease risk factors. Subclinical atherosclerosis is measured by quantitative B-mode ultrasonography of the carotid arteries, and other objective measures of vascular disease are a 12-lead electrocardiogram, a two-dimensional echocardiogram, ankle to arm blood pressure ratio and urine microalbumin concentration. The relationship between the conventional and emerging risk factors, and atherosclerosis, vascular disease and markers of end-organ damage will be evaluated between and within ethnic groups.

Adult↗
PubMed1997

CD84 leukocyte antigen is a new member of the Ig superfamily.

cDNA isolated from a human B-cell line Raji library was analyzed and shown to encode the full-length cDNA sequence of a novel cell-surface glycoprotein, initially termed HLy9-beta. The predicted mature 307-amino acid protein was composed of two extracellular Ig-like domains, a hydrophobic transmembrane region, and an 83-amino acid cytoplasmic domain. The extracellular Ig-like domains presented structural and sequence homology with a group of members of the Ig superfamily that included CD2, CD48, CD58, and Ly9. Northern blot analysis showed that the expression of HLy9-beta was predominantly restricted to hematopoietic tissues. Chromosome localization studies mapped the HLy9-beta gene to chromosome 1q24, where other members of this Ig superfamily (CD48 and HumLy9) have been mapped. CD84 monoclonal antibodies (MoAbs) were shown to react with cells transfected with the cloned cDNA. These MoAbs were further used to show that CD84 is expressed as a single chain cell-surface glycoprotein of Mr 64,000 to 82,000, which was highly glycosylated. CD84 had a unique pattern of expression, being found predominantly on lymphocytes and monocytes. Thus, the glycoprotein HLy9-beta is recognized by MoAbs previously clustered as CD84 and represents a newly identified member of the Ig superfamily that may play a significant role in leukocyte activation.

Amino Acid Sequence↗
PubMed1997

Circulatory effects of graded diversion of portal blood flow to the systemic circulation in rats: role of nitric oxide.

Total portal-systemic shunting in normal animals is associated with splanchnic and systemic vasodilation, suggesting that vasodilation in cirrhosis may be facilitated by spontaneous shunts promoted by portal hypertension. However, the mechanism of this vasodilation is unknown. The aim is to study the acute effects of the graded diversion of portal blood flow to the systemic circulation in normal and portal hypertensive rats. Portal and systemic hemodynamics were measured in normal and portal hypertensive rats before and during graded portacaval diversion of portal blood flow, in basal conditions, and after nitric oxide inhibition. In portal hypertensive rats, graded portal flow diversion caused a rate-related decrease in portal pressure (from 15.3 +/- 0.6 to 11.2 +/- 0.7 mm hg at 6 mL x min(-1), P < .001) and a redistribution of portal-collateral blood flow from the spontaneous portal-systemic collaterals to the portacaval circuit, without changing total portal-systemic shunting. Graded portal diversion caused an immediate systemic vasodilation, with reduced peripheral resistance. This vasodilatory response was more pronounced in normal than in portal hypertensive rats (increase in cardiac index 23.6% +/- 2.8% vs. 8.5% +/- 4.9%, P < .02, fall in peripheral resistance -24.5% +/- 3.4% vs. -16.5% +/- 2.6%, P = .08), and was totally prevented by nitric oxide inhibition. The graded diversion of portal blood flow caused a flow-rate-related reduction in portal pressure and blood flow through spontaneous portal-systemic collaterals in portal hypertensive rats, and caused a nitric-oxide dependent systemic vasodilatory response, which was greater in normal than in portal hypertensive rats. These results suggest that portal-systemic shunting per se may contribute to the vasodilatation in portal hypertension.

Animals↗
PubMed1997

Male advertisement call and female preference in sympatric and allopatric midwife toads

Advertisement calls and female preferences in allopatric populations of midwife toads, Alytes obstetricans and A. cisternasiiwere compared with those in a sympatric population. These species have simple tonal advertisement calls which overlap substantially in frequency and duration. In both species, the duration of male advertisement calls did not differ between an allopatric and a sympatric population. Playback tests suggested that females in allopatric populations preferentially approach low frequency calls and long calls, exerting directional selection for larger males and males with longer calls. Female A. cisternasii from the sympatric zone did not prefer low frequency calls, which could be made by males of A. obstetricansSimilarly, female A. obstetricans from the sympatric zone did not preferentially approach long calls, which could be made by A. cisternasii males. The differences in female preference between sympatry and allopatry follow the expected direction of reproductive character displacement. Within each species, female preferences differed clearly between sympatry and allopatry while male call characteristics did not.Copyright 1997 The Association for the Study of Animal BehaviourCopyright 1997The Association for the Study of Animal Behaviour.

Journal Article↗
PubMed1997

Acute effects of ethanol on mineral metabolism and trabecular bone in Sprague-Dawley rats.

In order to assess the effects of acute ethanol intoxication on bone, 45 female Sprague-Dawley rats were studied. Five rats were sacrificed at baseline. The remainder received either ethanol (2 g/kg of body weight) intraperitoneally or isotonic saline. Rats were sacrificed in groups of 10 (5 intoxicated and 5 placebo) at 1, 4, 8, and 24 hours after injection. At the time of sacrifice, a blood sample was obtained and the 4th vertebra was excised for histomorphometric analysis of undecalcified bone. Effect of ethanol was assessed by an analysis of variance test using a Scheffé procedure. In ethanol-treated rats we observed (mean +/- SD, ethanol versus controls, maximum difference point, P value) a significant decrease in osteiod surface with osteoblasts (42.86 +/- 15.61% versus 64.57 +/- 6.24%, P < 0.05); osteoclast number (0.05 +/- 0.02 n/mm2 versus 0.17 +/- 0.09 n/nm2, P < 0.05), and osteocalcin (36.9 +/- 2.21 ng/ml versus 45.8 +/- 5.1 ng/ml, P < 0.05). Osteoclast surface was initially reduced (0.129 +/- 0.09% versus 0.425 +/- 0. 26%, P < 0.01) but showed a subsequent increase (0.765 +/- 0.24% versus 0.226 +/- 0.17%, P < 0.01) attributable to alcohol. There was also a significant decrease in serum Ca (8.51 +/- 0.23 mg/dl versus 9.10 +/- 0.29 mg/dl, P < 0.01) and parathyroid hormone values (23.51 +/- 5.72 pg/ml versus 76.39 +/- 11.66 pg/ml, P < 0.001). We conclude that acute alcohol intoxication in rats induces early striking changes in bone histology and analytical parameters, not completely reversed after 24 hours. These data are consistent with a toxic effect induced by alcohol on bone.

Acid Phosphatase↗
PubMed1997

Effects of ethanol consumption on hepatic hemodynamics in patients with alcoholic cirrhosis.

BACKGROUND & AIMS: Increased portal blood flow represents a compensatory mechanism preventing hepatic hypoxia after ethanol consumption. In addition, alcohol increases hepatic vascular resistance. Thus, ethanol consumption, by increasing hepatic vascular resistance and portal flow, may worsen portal hypertension in patients with cirrhosis. The aim of this study was to investigate the effects of ethanol consumption on hepatic hemodynamics in patients with alcohol-induced cirrhosis. METHODS: Measurements of hepatic venous pressure gradient (HVPG), azygos blood flow, hepatic blood flow, heart rate, and arterial pressure were obtained in 16 patients with alcohol-induced cirrhosis and portal hypertension before and after random administration of a noncaloric fruit drink (250 mL, n = 7) or of an identical beverage plus 0.5 g/kg of ethanol (n = 9). RESULTS: Vehicle caused no effects. By contrast, ethanol increased HVPG (P < 0.0001). The increase in HVPG was maximum at 15 minutes and remained significant at 45 minutes (P < 0.05 vs. vehicle). Ethanol increased azygos blood flow (P < 0.05) without changes in hepatic blood flow. Heart rate and arterial pressure slightly increased. CONCLUSIONS: Oral ethanol consumption increases portal pressure and portocollateral blood flow in patients with alcohol-induced cirrhosis. These findings suggest that even moderate alcohol consumption worsens the portal-hypertensive syndrome and, therefore, may increase the risk of variceal bleeding in patients with alcohol-induced cirrhosis.

Adult↗