Search PubMed⌕ Search

Biomedical subjects

I Thomas

Publications and source records attributed to I Thomas.

At least 37 records · Page 2Linked to original sources

Two new loci for autosomal recessive ichthyosis on chromosomes 3p21 and 19p12-q12 and evidence for further genetic heterogeneity.

Autosomal recessive ichthyosis (ARI) includes a heterogeneous group of disorders of keratinization characterized by desquamation over the whole body. Two forms largely limited to the skin have been defined: lamellar ichthyosis (LI) and nonbullous congenital ichthyosiform erythroderma (NCIE). A first gene for LI, transglutaminase TGM1, has been identified on chromosome 14, and a second one has been localized on chromosome 2. In a genomewide scan of nine large consanguineous families, using homozygosity mapping, two new loci for ARI were found, one for a lamellar form in a 6-cM interval on chromosome 19 and a second for an erythrodermic form in a 7.7-cM interval on chromosome 3. Linkage to one of the four loci could be demonstrated in more than half of 51 consanguineous families, most of them from the Mediterranean basin. All four loci could be excluded in the others, implying further genetic heterogeneity in this disorder. Multipoint linkage analysis gave maximal LOD scores of 11.25 at locus D19S566 and 8.53 at locus D3S3564.

Chromosome Mapping↗

PCR detects HCV RNA in a plasma pool contaminated by a single preseroconversion donation of genotype 5a.

BACKGROUND AND OBJECTIVES: To determine the prevalence of HCV-RNA-positive plasma pools in Belgium, to validate our PCR method and to increase the safety of the released blood products. MATERIALS AND METHODS: Plasma pools consisting each of about 5,000 donations from Belgian unpaid volunteer blood donors were analysed by PCR for the presence of HCV RNA. Two different extraction methods were compared and validated. RESULTS: Two out of 367 plasma pools were found to be HCV RNA positive and were discarded. For one of these two pools, the look-back procedure identified an anti-HCV-negative contaminated donation. The HCV genotype of both the contaminated pool and the donation was 5a, a genotype rare in Europe. The viral load of the preseroconverted donation was 2.9 x 10(7) gEq/ml according to the bDNA method. CONCLUSION: In the case of plasma derivatives, various important steps are already included to increase safety. Nucleic acid testing of manufacturing plasma pools ensures that viral load in the starting material is as low as possible.

Belgium↗

Maintaining gut integrity during parenteral nutrition of tumor-bearing rats: effects of glucagon-like peptide 2.

Maintaining tumor-bearing rats on total parenteral nutrition (TPN) for eight days significantly reduced mass, protein, and DNA in small intestine and colon. Coinfusion of glucagon-like peptide 2 (GLP-2) significantly increased each of these variables in the duodenum, jejunum, and ileum, but not in the colon. Histological analysis of tissue revealed normal mucosa thickness and villus height in the small intestine of GLP-2-treated rats, whereas non-treated rats maintained on TPN exhibited villus shortening and thinning of the mucosa. Compared with TPN alone, no significant effects of GLP-2 were noted on tumor growth, liver weight, or heart weight. Coinfusion of GLP-2 with TPN had no significant effect on TPN-associated immunosuppression, as measured by mitogen-induced proliferation of cultured splenocytes. Although translocation of bacteria to the mesenteric lymph nodes appeared to be reduced in GLP-2-treated rats, the difference between groups was not statistically significant. These results suggest that hormonal alterations may be more important than an absence of luminal nutrition in TPN-associated mucosa changes in tumor-bearing rats. Additionally, maintenance of gut integrity during TPN does not appear to be a sufficient condition for the avoidance of the negative sequelae associated with this route of supplemental nutrition.

Animals↗

Dose-related beneficial long-term hemodynamic and clinical efficacy of irbesartan in heart failure.

OBJECTIVES: The primary purpose of this study was to determine the acute and long-term hemodynamic and clinical effects of irbesartan in patients with heart failure. BACKGROUND: Inhibition of angiotensin II production by angiotensin-converting enzyme (ACE) inhibitors reduces morbidity and mortality in patients with heart failure. Irbesartan is an orally active antagonist of the angiotensin II AT1 receptor subtype with potential efficacy in heart failure. METHODS: Two hundred eighteen patients with symptomatic heart failure (New York Heart Association [NYHA] class II-IV) and left ventricular ejection fraction < or = 40% participated in the study. Serial hemodynamic measurements were made over 24 h following randomization to irbesartan 12.5 mg, 37.5 mg, 75 mg, 150 mg or placebo. After the first dose of study medication, patients receiving placebo were reallocated to one of the four irbesartan doses, treatment was continued for 12 weeks and hemodynamic measurements were repeated. RESULTS: Irbesartan induced significant dose-related decreases in pulmonary capillary wedge pressure (average change -5.9+/-0.9 mm Hg and -5.3+/-0.9 mm Hg for irbesartan 75 mg and 150 mg, respectively) after 12 weeks of therapy without causing reflex tachycardia and without increasing plasma norepinephrine. The neurohormonal effects of irbesartan were highly variable and none of the changes was statistically significant. There was a significant dose-related decrease in the percentage of patients discontinuing study medication because of worsening heart failure. Irbesartan was well tolerated without evidence of dose-related cough or azotemia. CONCLUSIONS: Irbesartan, at once-daily doses of 75 mg and 150 mg, induced sustained hemodynamic improvement and prevented worsening heart failure.

Adolescent↗

Acute excisional wounds treated with a tissue-engineered skin (Apligraf).

BACKGROUND: Tissue-engineered products are usually composed of living cells and their supporting matrices that have been grown in vitro, using a combination of engineering and life sciences principles. Apligraf is a bilayered product composed of neonatal-derived dermal fibroblasts and keratinocytes, and Type I bovine collagen. OBJECTIVE: To evaluate in a prospective, multicentered open study, the effects of tissue therapy with a tissue-engineered skin (Apligraf) with partial or full-thickness excisional wounds. METHODS: One hundred and seven patients participated in this study. The tissue-engineered skin was applied once, immediately after excisional surgery, usually for skin cancer, and patients were followed for up to one year. RESULTS: The safety results were impressive, with no clinical or laboratory evidence of rejection. Clinically, graft persistence was good to excellent in 77 of 105 (73.3%) of patients at one week, falling to 56.6% and 53.6% at two weeks and one month respectively. CONCLUSION: To date, this is the largest experience with a tissue-engineered skin product in acute wounds, and this study suggests that tissue therapy may be safe and useful.

Animals↗

A case-control study after a hantavirus infection outbreak in the south of Belgium: who is at risk?

Puumala is the most common hantavirus serotype in Europe and is spread mainly by the red bank vole. Between 1 July 1992 and 31 January 1994, an outbreak of Puumala virus-induced nephropathia epidemica (NE) occurred in the Belgian Ardennes. Serologically confirmed cases (n = 41) were compared with two groups of asymptomatic seronegative controls. Risks identified included sighting of living rodents, exposure to rodent droppings, and trapping rodents during the 4 weeks preceding onset of symptoms. Activities during this 4-week period that presented the greatest risk were woodcutting, reopening of a nonaerated room, and strenuous physical effort. This is the first case-control study on risk factors for NE in Europe. In comparison with the American form of hantavirus pulmonary syndrome, which is spread by deer mice, professional activity appears to be a more important risk factor for acquisition of hantavirus in Europe.

Adolescent↗

[Apropos of 1 case of hepatogastric fascioliasis in Cape Verde].

The authors report a case of Fascioliasis sp. distomiasis with a double hepatic and gastric location primitively associated with a gastric cancer metastazed to the liver. The parasitic origin of the lesions suspected from the histological specimen of the gastric biopsy (the presence of eggs) was confirmed by serology with the presence of the arc 2 specific to immunoelectrophoretic analysis, while the parasitological examination of the stools was always negative. The patient grew well after a day's cure of triclabendazole (375 mg x 2). Although the ectopic locations of Fascioliasis are classic, they are usually in the abdominal wall, less frequently in the gastric or colic wall. The fact that the contamination originated on the Cape Verde is indiscutable, since the patient had never left the island. It is the 5th case described in medical literature, thus confirming the presence of Fasciola hepatica (or gigantica) on the islands of the Cape Verde, whose population is of both Portuguese and African origin and has kept the eating habits of the former colonial power (Portugal is a zone of high endemicity for human fascioliasis). It would be interesting to look for Limnaea and contaminated bovine on the Cape Verde islands.

Africa, Western↗

Randomised trial of losartan versus captopril in patients over 65 with heart failure (Evaluation of Losartan in the Elderly Study, ELITE)

BACKGROUND: To determine whether specific angiotensin II receptor blockade with losartan offers safety and efficacy advantages in the treatment of heart failure over angiotensin-converting-enzyme (ACE) inhibition with captopril, the ELITE study compared losartan with captopril in older heart-failure patients. METHODS: We randomly assigned 722 ACE inhibitor naive patients (aged 65 years or more) with New York Heart Association (NYHA) class II-IV heart failure and ejection fractions of 40% or less to double-blind losartan (n = 352) titrated to 50 mg once daily or captopril (n = 370) titrated to 50 mg three times daily, for 48 weeks. The primary endpoint was the tolerability measure of a persisting increase in serum creatinine of 26.5 mumol/L or more (> or = 0.3 mg/dL) on therapy; the secondary endpoint was the composite of death and/or hospital admission for heart failure; and other efficacy measures were total mortality, admission for heart failure, NYHA class, and admission for myocardial infarction or unstable angina. FINDINGS: The frequency of persisting increases in serum creatinine was the same in both groups (10.5%). Fewer losartan patients discontinued therapy for adverse experiences (12.2% vs 20.8% for captopril, p = 0.002). No losartan-treated patients discontinued due to cough compared with 14 in the captopril group. Death and/or hospital admission for heart failure was recorded in 9.4% of the losartan and 13.2% of the captopril patients (risk reduction 32% [95% CI -4% to + 55%], p = 0.075). This risk reduction was primarily due to a decrease in all-cause mortality (4.8% vs 8.7%; risk reduction 46% [95% CI 5-69%], p = 0.035). Admissions with heart failure were the same in both groups (5.7%), as was improvement in NYHA functional class from baseline. Admission to hospital for any reason was less frequent with losartan than with captopril treatment (22.2% vs 29.7%). INTERPRETATION: In this study of elderly heart-failure patients, treatment with losartan was associated with an unexpected lower mortality than that found with captopril. Although there was no difference in renal dysfunction, losartan was generally better tolerated than captopril and fewer patients discontinued losartan therapy. A further trial, evaluating the effects of losartan and captopril on mortality and morbidity in a larger number of patients with heart failure, is in progress.

Aged↗

Prevention of parenteral nutrition-induced gut hypoplasia by coinfusion of glucagon-like peptide-2.

Maintaining rats on total parenteral nutrition (TPN) for 6 days significantly reduced mass (-34%), protein (-32%), and DNA (-35%) in small intestine and colon (29-37% decrease). Coinfusion of glucagon-like peptide-2 (GLP-2) normalized each of these variables in duodenum, jejunum, and ileum, but not in colon. Histological analysis of tissue revealed normal mucosa thickness and villus height in small intestine of GLP-2-treated rats, whereas nontreated rats maintained on TPN exhibited villus shortening (-30%) and thinning (-23%) of mucosa. These results suggest that hormonal alterations may be more important than an absence of luminal nutrition in TPN-associated mucosal changes. Additionally, GLP-2 normalization of gut mucosa permits accurate assessment of the influence of reversal of hypoplasia on gut barrier function.

Animals↗

Purification and sequencing of multiple forms of Brassica napus seed napin small chains that are calmodulin antagonists and substrates for plant calcium-dependent protein kinase.

Six napin small (S) subunits and six napin large (L) subunits were resolved from the seeds of kohlrabi (Brassica napus var. rapifera) by a procedure involving extraction, batchwise elution from carboxymethylcellulose (CM52) and reverse-phase HPLC after treatment with guanidine hydrochloride and 2-mercaptoethanol. The precise average molecular masses of the ca. 4.5 kDa small subunits and the ca. 10 kDa large subunits were determined by electrospray ionisation mass spectrometry (ESMS). The amino-acid sequences of six small subunits (S1A, S1B, S2, S3A, S3B and S4) were deduced from the ESMS-based masses of tryptic fragments, Edman sequencing and previously published data. The deduced structures were precisely consistent with this data and with the ESMS-based average molecular masses of these polypeptides. The structures of the small subunits (39-41 residues) are very similar with variations involving single substitutions at or near the N-terminus and 1 to 3 changes within the last 7 amino acids. Particular B. napus small and large chains are phosphorylated by plant Ca2+-dependent protein kinase (CDPK). The best site of phosphorylation on small chains is inferred to be either S34 or S39 of S1B. The napin-containing basic protein fraction from B. napus seeds largely abolishes the Ca2+-dependent fluorescence enhancement of dansyl-calmodulin and also inhibits calmodulin (CaM)-dependent myosin light chain kinase (MLCK). The resolved napin small chains also inhibit MLCK. All of the kohlrabi napin small chains, as well as homologous Brassicaceae small chains, have a central 23 amino-acid sequence that can potentially form an alpha-helix in which all the basic residues are located on one side. This structural element may be involved in the interaction of these proteins with CaM and the biological activity of antifungal proteins of this kind.

2S Albumins, Plant↗

Purification and sequencing of multiple forms of Brassica napus seed napin large chains that are calmodulin antagonists and substrates for plant calcium-dependent protein kinase.

Six napin large (L) chains (as well as six napin small chains) were resolved from the seeds of kohlrabi (Brassica napus var. rapifera) by a procedure involving extraction, batchwise elution from carboxymethylcellulose (CM52) and reversed-phase HPLC after treatment with guanidine hydrochloride and 2-mercaptoethanol. The precise average molecular masses of the circa 4.5 kDa small subunits and the circa 10 kDa large subunits were determined by electrospray ionisation mass spectrometry (ESMS). Of six large subunits resolved (L1A), L1B, L1C, L2A, L2B and L2C), the complete amino acid sequences of four (L1A, L2A, L2B and L2C) and the near-complete sequences of two (L1B and L1C) were deduced from the ESMS-based masses of tryptic fragments, Edman sequencing and previously published data. The deduced structures are precisely consistent with this data and with the ESMS-based average molecular masses of these polypeptides. ESMS analysis of unreduced napin extract revealed only seven circa 14.5 kDa complexes, the observed masses being in close agreement with those calculated for 1:1 complexes of particular small and large subunits assuming four disulfides in each napin complex. The structures of the napin large subunits (86-91 residues) are very similar and all amino acid differences observed are confined to only 25 positions. The L2A, L2B AND L2C large chains (but not the L1A, L1B and L1C large chains) are phosphorylated well by plant Ca2+-dependent protein kinase (CDPK). The CDPK-catalyzed phosphorylation site on the large chain L2A is inferred to be S57 within the sequence LQQVIS57RIYQT (the site being S60 within the same sequence in L2B and L2C). The napin-containing basic protein fraction from B. napus seeds largely abolishes the Ca2+-dependent fluorescence enhancement of dansyl-calmodulin and also inhibits calmodulin (CaM)-dependent myosin light chain kinase (MLCK). The resolved napin long chains also inhibit MLCK. Each kohlrabi large chain contains 2 sequences (corresponding to L(10)-Q(20) and Q(51)-L(64) of L1A) which have the potential to form amphipathic alpha-helices. Each large chain also contains a Q-rich 19 amino acid sequence (corresponding to L(30)-Q(48) of L1A) which has the potential to form a '2-sided' alpha-helix with basic residues confined to one side. These structural elements may be involved in the inferred interaction of these proteins with CaM and may be relevant to the biological activity of antifungal proteins of this kind.

2S Albumins, Plant↗

Spatial data aggregation: exploratory analysis of road accidents.

This paper is limited to the "size problem": it empirically and systematically examines to what extent the length of road segment influences the statistical description of accident counts and density. Univariate descriptive statistics are systematically measured for accident count and ratio, using different motorway segment lengths. A classification of the studied aggregation levels is proposed leading to three distinct groups of segments: (1) very small segments (1 hm), where observed accident counts are almost Poisson distributed, (2) large segments (more than 20 hm), where accident counts are almost normally distributed, and (3) medium size segments (3-20 hm), where accident counts have an intermediate empirical distribution. It is suggested that generalizations made at one level of spatial aggregation may not necessarily hold at another level. Conclusions derived at one scale may be invalid at another. The paper shows how important preliminary examination of the data can be, without any sophisticated statistical test. It also shows that one best or unique level of aggregation is not available: it depends upon the objective of the study. Results of any statistical analysis or modelling procedure should be seen as conditional on the scale of the analysis.

Accidents, Traffic↗

Vancomycin-induced linear IgA bullous dermatosis (LABD).

We report the eleventh case of vancomycin-induced linear IgA disease. Our case is unusual because symptoms developed within minutes of administration of the drug. We discuss the pathogenesis and review the literature.

Anti-Bacterial Agents↗

Immunostimulation following fish oil-based parenteral nutrition in tumor-bearing rats.

Tumor-bearing (TB) and control rats were maintained for four to seven days on total parenteral nutrition (TPN) in which the lipid component (11.1% of total calories) was Intralipid or fish oil. Although no TB rats maintained on standard Intralipid-based TPN died prematurely in these experiments, one-third of the TB rats maintained on fish oil-based TPN died of bleeding complications by Day 4 of TPN infusion. The bleeding appeared to be due to the particle size in the fish oil emulsion, because a subsequent study employing a better emulsified TPN with smaller lipid particles exhibited fewer bleeding problems. Tumor growth, skeletal muscle atrophy, and gut hypoplasia were not reduced in the TB group maintained on fish oil-based TPN. However, immunosuppression observed in the Intralipid-based TPN group, as measured by mitogen response of cultured splenocytes, was significantly improved in the rats maintained on fish oil-based TPN. Levels of eicosapentaenoic acid were reduced in all rats receiving TPN. Although the hypothesized antitumor and anticachexia effects of fish oil administration were not realized, significant improvement in immunosuppression was noted. These results suggest that intravenously administered fish oil may have potential positive effects for the host.

Animals↗

Sharing antenatal care: client satisfaction and use of the 'patient-held record'.

Two hundred women (148 shared care patients and 52 clinic patients) completed a questionnaire about care received during pregnancy and the use of a patient-held record. Women receiving shared care reported higher levels of satisfaction with their care than clinic patients (p < 0.0001). Thirty-six percent of the women in shared care forgot to take their record to an appointment on at least 1 occasion. During the pregnancy, over half of the respondents in both groups made contact with the hospital for reasons other than for their regular visit. For both groups, convenience was the most frequently reported reason for choosing their model of care. Other important issues for shared care patients were that the service was more personal and more information was provided. Among clinic patients, safety and quality of care were identified as important. Problems involved with the patient holding the only complete pregnancy record are discussed.

Family Practice↗

Anorectic and neurochemical effects of pituitary adenylate cyclase activating polypeptide in rats.

Pretreatment of rats with intrahypothalamic injections of pituitary adenylate cyclase activating peptide (PACAP) 10 min prior to the injection of neuropeptide Y (NPY) significantly reduced food and water intake during the 4-h measurement period. Intrahypothalamic injection of PACAP in schedule-fed rats also reduced food and water intake for 2 h. A smaller 1-h reduction of water intake was observed in water-deprived rats, suggesting that the anticonsummatory effects of PACAP were primarily against food intake. PACAP treatment did not alter hypothalamic concentration of NPY, nor were neurotransmitters, precursors, or metabolites altered substantially in corpus striatum or nucleus accumbens regions. These results demonstrate primary anorectic effects of intrahypothalamic injection of PACAP. The demonstration of these anorectic effects may suggest a role of cyclic AMP activation and inhibition in the control of satiety and hunger.

Adenylyl Cyclases↗

Oral candidosis.

Explore the source record for details and available documents.

AIDS-Related Opportunistic Infections↗