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Biomedical subjects

I Paul

Publications and source records attributed to I Paul.

At least 37 records · Page 2Linked to original sources
PubMed1999

Cheilognathopalatoschisis and its prophylaxis in animal experiments.

Cheilognathopalatoschisis (cleft lip, -maxilla, and -palate) is the second most frequent malformation in humans. The ontogenetic causes are mostly multifactorial. Some researchers have succeeded in lowering the frequency of occurrence of such clefts in children of predisposed women by giving the latter an applied symptomatic replacement therapy with multivitamin preparations or other substance classes during early pregnancy. However, the dosage of these substances was only anecdotal and their effect unspecific. Many research groups world-wide are conducting animal experiments in order to investigate the efficacy of vitamins and other substances as prophylactics. The experiments are usually conducted with laboratory rats and mice, and clefts are often induced by applying chemical noxa. The results of these trials, however, are controversial. Where some authors were able to prove protective effects of the vitamins or other substances they employed, others found evidence that such replacement therapy has no prophylactic effect. This paper provides insight into such studies with experimental animals, and compares their results.

Animals↗
PubMed1999

An isolation procedure for arachidonic acid producing Mortierella species.

Malt extract agar and an incubation temperature of 5 degrees C were used to selectively isolate representatives of the genus Mortierella from soil. Fungi in a soil sample from mountain grassland able to grow under these conditions, amounted to a total of 2640 colony forming units per gram soil. Circa 94% of the total fungal isolates represented Mortierella subgenus Mortierella. The rest of the colony-forming units consisted of Mucor isolates (6.0%) and higher fungi (1.5%). All the Mortierella isolates produced arachidonic acid.

Arachidonic Acid↗
PubMed1999

Quantitative assessment of Ascaris lumbricoides infection in school children from a slum in Visakhapatnam, south India.

An epidemiological study was conducted on 217 school children aged between 7-13 years, from Relliveedhi a slum in Visakhapatnam, Andhra Pradesh, south India, during August 1993 to August 1994. The children belonged to a socioeconomically backward community-parental occupation being fishing or waged labor. Intensity and prevalence estimations for Ascaris lumbricoides were done indirectly by formalin-ethyl-acetate sedimentation technic and directly by worm expulsions following albendazole administration at a single oral dose of 400 mg/child. Prevalence rate was 73% while the intensity of infection ranged between low to moderate. Boys had severe infection than girls due to their outdoor activities and behavioral habits. Nine year old children had the highest prevalence rates. Mean Ascaris worm intensity was 2.2 (+/-1.91) with an over-dispersed distribution of the parasite in the host population. Reinfection study over a period of nine month showed that the prevalence rates exceeded the pre-intervention level but the intensity of infection was very low. Dual species intensity correlation between Ascaris and Trichuris was consistently strong.

Adolescent↗
PubMed1998

Can serology diagnose upper genital tract Chlamydia trachomatis infections? Studies on women with pelvic pain, with or without chlamydial plasmid DNA in endometrial biopsy tissue.

BACKGROUND: Upper genital tract chlamydial infections in women are on the increase, and serology might be a convenient tool for diagnosis. Evaluations of this approach are needed in women with or without microbiologic evidence of organisms in the upper genital tract. GOALS: To compare the results of antibody assays with cervical culture and upper genital tract histopathology in women with pelvic pain and chlamydial plasmid DNA in endometrial biopsies. STUDY DESIGN: Chlamydia trachomatis plasmid DNA was detected by polymerase chain reaction (PCR) on extracted deparaffinized endometrial biopsy tissue. Five antichlamydial antibody assays were performed measuring total antibodies or immunoglobulin G (IgG), IgM, and IgA classes on sera from 14 women with plasmid DNA as well as 31 without plasmid DNA. RESULTS: Accepting the presence of plasmid DNA as the gold standard, no single test had total diagnostic accuracy. The best sensitivity and specificity occurred with the following assays: whole inclusion fluorescence (WIF) (100% and 80.6%); microimmunofluorescence IgM (MIF IgM) (78.6% and 93.6%); and heatshock protein-60 enzyme immunoassay (42.9% and 100%). Although recombinant anti-lipopolysaccharide enzyme-linked immunosorbent assays measured anti-chlamydial antibodies in a large proportion of these women, specificity was low. The sensitivity and specificity of cervical culture was 28.6% and 100% and of endometrial histopathology was 71.4% and 48.4%. Analysis of patient serological profiles suggested that and 6 women without plasmid DNA may have been cases that were missed by PCR. CONCLUSIONS: Evaluations of assays to diagnosis Chlamydia trachomatis upper genital tract infections could use the presence of organisms or their markers in the upper genital tract as a standard of comparison. Some of these serological assays, such as WIF or MIF IgM, may be helpful in diagnosis, but more studies are needed.

Antibodies, Bacterial↗
PubMed1998

Re-infection estimation of soil-transmitted helminths among slum school children in Visakhapatnam, Andhra Pradesh.

Prevalence and intensity study of soil-transmitted helminths was carried out in a primary municipal corporation school in Relliveedhi, Visakhapatnam, Andhra Pradesh. All subjects (n = 217) belonged to low socio-economic status with an age distribution of 7-13 years. Reinfection study was estimated over a nine month period following treatment with albendazole administered at a single oral dose of 400 mg/child. Parasites identified were Ascaris lumbricoides, Trichuris trichiura and hookworm. Post-treatment prevalence reached pre-intervention level but the intensity of infection remained appreciably low (p < 0.05).

Adolescent↗
PubMed1997

Rapid detection and serotyping of adenovirus by direct immunofluorescence.

Four fluorescent antibody reagents were evaluated for their suitability for the identification of adenovirus isolates by immunofluorescence. The antibodies used in the reagents consist of monoclonal antibodies against adenovirus type 3 (Ad3), Ad4, Ad8, and adenoviruses of subgroup C (Ad1,2,5,6), serotypes known to occur in outbreaks of disease. Most of the monoclonal antibodies employed were reactive against type-specific antigens found on the hexon protein. Reagents employing two noncompeting anti-hexon antibodies were more sensitive than reagents prepared with only one monoclonal antibody, although both types of reagents exhibited a high degree of specificity. Five hundred and seventeen adenovirus isolates (359 of which had previously been typed by other methods) and 46 nonadenovirus isolates were examined with all four type-specific reagents in parallel with an adenovirus group-specific reagent. The results indicate that direct typing of adenovirus isolates is feasible, leading to significant savings in time compared to other typing methods and should contribute to the management of certain adenovirus infections, particularly during outbreaks.

Adenoviridae Infections↗
PubMed1997

Hormonal factors and the laboratory detection of Chlamydia trachomatis in women: implications for screening?

One thousand and fifty-six new and re-registered consecutive women attending a genitourinary medicine clinic requiring speculum examination were screened for Chlamydia trachomatis by enzyme immunoassay (IDEIA, Dako Diagnostics Ltd). Of 1022 women who had results available for both cervix and urethra C. trachomatis was detected in 8.8% (89/1022) in any site, 2.3% (23/1022) in both sites, 4.9% (51/1022) at the cervix alone and 1.5% (15/1022) at the urethra alone. Thus sampling at the urethra increased detection by 17% (15/89). Analysis of 808 women with a regular menstrual cycle showed a significant association of combined oral contraceptive use, age and ectropion with the detection of C. trachomatis. The detection of C. trachomatis showed a significant variation with the menstrual cycle (P = 0.023) (relative risk (rr) 1.7 (95% confidence intervals (CI) 1.0-2.8)). It was detected significantly more often in the latter part. Stepwise logistic regression analysis revealed that ectropion and age were the stronger determinants of C. trachomatis detection and not oral contraceptive use or menstrual cycle. The variation in detection of C. trachomatis with the menstrual cycle was independently associated with combined oral contraceptive use and the lack of a cervical ectropion. The increased detection at the cervix was present after the second week in combined oral contraceptive users (P = 0.008) (rr = 2.3 (1.2-4.5)) but only after the 3rd week in women without an ectropion (P = 0.004) (rr = 2.7 (1.3-5.5)). Combined oral contraceptives, ectropion and youth, are markers for the carriage of C. trachomatis in the lower genital tract of women. It is also detected significantly more often in the latter part of the menstrual cycle in women who are oral contraceptive users.

Adolescent↗
PubMed1995

Oxotremorine-m potentiation of glucose-induced insulin release from rat islets involves M3 muscarinic receptors.

cDNAs encoding for M1 and M3 muscarinic acetylcholine (ACh) receptors were detected in rat pancreatic islet cells by polymerase chain reaction (PCR) amplification techniques. A new cholinergic agonist, oxotremorine-m (oxo-m), in the presence of glucose (5.6 mM), produced a dose-dependent potentiation of insulin secretion saturating at approximately 5 microM. This effect was suppressed by the L-type Ca2+ channel blocker nifedipine. Higher doses of oxo-m (50 microM) induced a biphasic insulin response both at low (5.6 mM) or high (16.7 mM) glucose concentrations. In a Ca(2+)-deficient medium containing glucose (5.6 mM), oxo-m evoked only a reduced first phase of insulin secretion. The potentiating effects of oxo-m were inhibited by the muscarinic receptor antagonists 4-diphenylacetoxy-N-methylpiperidine methiodide (M3), hexahydro-sila-difenidol hydrochloride, p-fluoro analogue (M3 > M1 > M2), and pirenzepine (M1) in a dose-dependent manner; half-maximal inhibitory concentration values were approximately 5, 20, and 340 nM, respectively. The PCR results demonstrate the presence of M1 and M3 muscarinic ACh receptors in the islet tissue, and the secretion data strongly suggest that the potentiation of glucose-induced insulin release evoked by oxo-m depends on the activation of a muscarinic M3-subtype receptor present in the beta-cell membrane.

Animals↗
PubMed1992

An iron-sulfur cluster plays a novel regulatory role in the iron-responsive element binding protein.

Post-transcriptional regulation of genes important in iron metabolism, ferritin and the transferrin receptor (TfR), is achieved through regulated binding of a cytosolic protein, the iron-responsive element binding protein (IRE-BP), to RNA stem-loop motifs known as iron-responsive elements (IREs). Binding of the IRE-BP represses ferritin translation and represses degradation of the TfR mRNA. The IRE-BP senses iron levels and accordingly modifies binding to IREs through a novel sensing mechanism. An iron-sulfur cluster of the IRE-BP reversibly binds iron; when cytosolic iron levels are depleted, the cluster becomes depleted of iron and the IRE-BP acquires the capacity to bind IREs. When cytosolic iron levels are replete, the IRE-BP loses RNA binding capacity, but acquires enzymatic activity as a functional aconitase. RNA binding and aconitase activity are mutually exclusive activities of the IRE-BP, and the state of the iron-sulfur cluster determines how the IRE-BP will function.

Aconitate Hydratase↗
PubMed1990

Rapid transformation of [3H]cholesteryl ester in rat high-density lipoprotein: in vivo and in vitro studies.

[24,25-3H]Cholesteryl ester-labeled rat high-density and low-density lipoproteins were administered to recipient rats. Following death of the rats, a major portion of the radioactivity in administered [3H]cholesteryl ester-high-density lipoprotein rapidly appeared in less dense [3H]cholesteryl ester-lipoproteins and was isolated with the low-density lipoprotein fraction. The specific activity of the esterified cholesterol in the product lipoproteins found with the low-density lipoproteins exceeded that of the precursor high-density lipoproteins. In vitro, the addition of [3H]cholesteryl ester-high-density lipoprotein to plasma resulted in a five- to six-fold increase in radioactivity recovered in the low-density lipoprotein. These results demonstrate that, under a variety of experimental conditions, isolated high-density lipoprotein particles (both in vitro and in vivo) tend to become larger and less dense. Rapid changes in the density of lipoproteins labeled with [3H]cholesteryl ester must be considered when interpreting physiologic studies using this label.

Animals↗
PubMed1989

[Correlative morphological studies of the heart of guinea pigs].

Investigations were conducted to record the following morphological parameters from hearts of guinea pigs (alb/Jena, inbred strain): absolute and relative heart weight as well as weights of left and right ventricles and of the interventricular septum. Correlations are described and discussed between the values recorded as well as between those values and body weight and changes in the course of ageing. The point is made that investigations of this kind are helpful in describing heart development in its totality and may provide better prerequisites for appraisal of pathological conditions.

Aging↗
PubMed1987

Completeness and selectivity of ricin "suicide transport" lesions in rat dorsal root ganglia.

Ricinus communis agglutinin (MW 60 kDa type, RCA60, ricin) injected into the rat sciatic nerve produces massive degeneration of cells in those dorsal root ganglia (DRGs) known to contain the sensory cells-of-origin of the sciatic nerve. We have evaluated the extent of this cell death quantitatively. Using 1 or 2 micrograms RCA60, the average proportion of L5 DRG neurons destroyed closely matched the proportions of neurons in this ganglion known to have an axon in the sciatic nerve. A lower dose, 0.2 microgram ricin, produced substantially less cell death. There was heavy fiber degeneration in the sciatic nerve proximal to the injection site, but not in a nearby tributary nerve with which it shares the L5 DRG. Furthermore, the topographic distribution of Fink-Heimer argyrophilia corresponded to the known sciatic nerve distribution. The data suggest that at appropriate doses toxic ricin can produce a near complete and selective lesion by retrograde "suicide transport".

Animals↗
PubMed1986

Generation of plasma free cholesterol from circulating lipoprotein-associated cholesteryl ester.

Studies were performed to investigate the contribution of lipoprotein-associated cholesteryl ester (CE) in the monkey to circulating free cholesterol (FC). Monkey plasma was incubated with [14C]- or [3H]cholesteryl ester, and radiolabeled low-density lipoproteins (LDL) and high-density lipoproteins (HDL) were isolated by ultracentrifugation. Animals received labeled LDL or HDL. A rapid transfer of CE between lipoproteins was observed, consistent with an active CE transfer protein activity in the monkey. Within 4 h the percent of plasma radioactivity in FC after injection of CE-labeled LDL or HDL was, respectively, 30 and 7% of that of the ester. To determine whether the generation of FC was due to a circulating plasma cholesteryl ester hydrolase, monkey plasma was incubated with CE-labeled lipoproteins with and without 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB). A small amount of FC (less than 3% of the radioactivity) was generated during this incubation but most of the FC production was inhibited by DTNB. Although a small amount of FC can be produced by a plasma cholesteryl esterase (perhaps via reverse action of lecithin-cholesterol acyltransferase), most of the FC in plasma derived from lipoprotein-associated CE is probably due to tissue uptake of lipoproteins and subsequent intracellular hydrolysis of the CE to produce FC.

Animals↗
PubMed1983

Long-term effects of deendothelialization of rabbit aorta: in vitro synthesis of DNA, protein, and lipid.

To study the long-term local effects of a single balloon catheter deendothelialization of the aorta in the rabbit, the incorporation of [3H]leucine and [3H]thymidine into protein and DNA, respectively, and [14C]acetate and [14C]mevalonate into sterols was measured in incubations of intima-media sections prepared from vessels taken 1 year following the procedure. The uptake of [3H]thymidine by the tissue was essentially the same as in the nonballooned controls, but the incorporation of [3H]leucine and [14C]acetate into tissue residue (proteins and glycoproteins) was approximately nine times and four times control values, respectively. At the same time, sections from the ballooned animals incorporated over six times the amount of radioactive acetate into nonsaponifiable lipids and cholesterol than did controls. In animals ballooned 3 months before sacrifice, when about half of the aortic luminal surface was covered with endothelium, intima-media tissue from both covered and uncovered areas showed increased uptake of labeled precursors into protein, nonsaponifiables, and cholesterol but there was no significant difference in incorporation between reendothelialized and nonendothelialized areas. The persistence of increased metabolic activity in the vessel following the loss of endothelium could be a contributing factor in the atherogenic process.

Acetates↗