Search PubMed⌕ Search

Biomedical subjects

J Clement

Publications and source records attributed to J Clement.

At least 55 records · Page 3Linked to original sources

Serological evidence of Hantavirus disease in Northern Ireland.

Since, to our knowledge, no clinically documented cases of haemorrhagic fever with renal syndrome (HFRS) have been reported in Northern Ireland, a sero-epidemiological study was carried out to assess the degree of Hantavirus immunity in a group of 627 Northern Irish patients presenting with symptoms suggestive of HFRS and 100 healthy controls. IFA screening for IgG Hantavirus specific antibodies was carried out with a panel of up to 9 different Hantaviral antigens. IgM screening was performed using a commercially available mu-capture ELISA based upon two recombinant Hantaviral nucleocapsid antigens. A seropositivity of 2.1% (15/727) was recorded, with an almost exclusive reaction against a rat-derived R22VP30 strain of the Seoul serotype. Sole reliance upon non-rat-derived classic screening antigens Hantaan (HTN 76-118) and Puumala (CG 18-20) would have resulted in the detection of only 2/15 (13.3%) of cases in IgG IFA, and 8/14 (57.1%) of the cases in IgG ELISA. The findings indicate that for the first time in Europe, and more specifically in N. Ireland, non-laboratory outbreaks of HFRS may be caused by wild rats acting as a reservoir for a Seoul-like Hantavirus. Conventional Hantavirus serology using Hantaan and Puumala as screening antigens does not appear sufficient for the detection of such cases of HFRS. Hence, we propose the addition of a rat derived Hantaviral antigen to the antigen screening panel as a means of improving the specificity of the detection methods.

Animals↗

Long lasting effects of audiogenic seizures on synaptosomal neurotransmitter amino acids in Rb mice.

Long lasting alterations of synaptosomal amino acid neurotransmitters following a single or several audiogenic seizures and/or acoustic stimulations were investigated in six brain areas -olfactory bulbs (OB), amygdala (A), hippocampus (Hi), cerebellum (C), inferior colliculus (IC), pons-medulla (P)- of three sublines of Rb mice: audiogenic seizure-prone Rb1 and Rb2, seizure-resistant Rb3. Changes in the synaptosomal levels of aspartate (Asp), glutamate (Glu), taurine (Tau), 4-amino butyrate (GABA), glycine (Gly) and some closely related precursors, serine (Ser) and glutamine (Gln), were recorded 15-18 hours after a single or multiple acoustic stimulations. Changes were more frequent, or larger, after polystimulation. Some alterations appeared to be attributable to an effect of the acoustic stress. In both seizure-prone sublines, after a single or repeated seizures, an increase in synaptosomal Asp was observed in IC. Decreases in Asp and Tau in OB and Ser in A, an increase in Gln in IC were only observed after repeated seizures, in Rb1 and Rb2 mice.

Acoustic Stimulation↗

Efficacy of A-73209, a potent orally active agent against VZV and HSV infections.

A-73209 is a novel oxetanocin derivative with potent in vitro and in vivo activity against VZV, HSV-1, and HSV-2. A-73209 was two logs more potent than acyclovir against five thymidine kinase positive (TK+) strains of VZV in vitro (mean EC50 0.01 vs. 1.22 micrograms/ml). The activity of A-73209 was one log more potent than acyclovir against TK+ HSV-1 strains in vitro (EC50 = 0.03 vs. 0.32 micrograms/ml). A-73209 yielded a mean EC50 of 2.2 micrograms/ml compared to a mean EC50 of 0.37 micrograms/ml for acyclovir against a panel of TK+ HSV-2 strains in vitro. The in vitro activity of A-73209 against thymidine kinase negative or deficient strains of VZV, HSV-1 and HSV-2 was much lower than for the corresponding TK+ strains. A-73209 produced efficacy superior to acyclovir against lethal systemic or intracerebral HSV-1 infections in mice. The greater efficacy of A-73209 relative to acyclovir was especially apparent with oral dosing. Against HSV-2 infections in mice, the efficacy of A-73209 ranged from equal to 1.7 times less active relative to acyclovir with oral dosing. A-73209 was orally bioavailable in mice, with maximal serum concentrations well in excess of in vitro inhibitory concentrations. A-73209 appears to be a potent and selective agent against varicella-zoster virus and herpes simplex virus infections.

Acyclovir↗

Treatment of experimental Pneumocystis carinii infection by combination of clarithromycin and sulphamethoxazole.

The efficacy of clarithomycin and sulphamethoxazole for treatment of experimental Pneumocystis carinii infection was investigated. Rats were immunosuppressed with dexamethasone and inoculated intratracheally with 5 x 10(6) P. carinii cysts. After 2 weeks, the lung tissues were assayed for P. carinii cyst burden. The combination of clarithromycin and sulphamethoxazole caused a significantly greater reduction in cyst burden than either drug alone. Up to 50% of the rats treated with the combination of clarithromycin and sulphamethoxazole were negative for P. carinii cysts. Equivalent doses of the individual drugs given alone did not produce cures. The combination of clarithromycin and sulphamethoxazole was more than twice as effective as either drug alone. Clarithromycin combined with sulphamethoxazole in treatment of P. carinii infection could be especially useful since clarithromycin monotherapy provides safe and effective treatment against many other pathogens, including several that are associated with AIDS.

Animals↗

Enteral formula composition does not affect response to lethal infectious challenge in mice.

The effects of enteral formulations on the response of mice to infectious challenge with Listeria monocytogenes, influenza A or Candida albicans were studied to test the efficacy of specialized ingredients. CF-1 outbred female mice (12-15 g) were fed nonpurified diet (Purina No. 5002) or commercially available liquid formulas: Osmolite HN, Perative or Impact. There were no differences between the groups fed the liquid formulas with regards to mean survival time or percentage of survivors in any of these models of infection. Examination of spleens from the groups challenged with L. monocytogenes, lungs from mice infected with Influenza A and kidneys from the groups challenged with C. albicans revealed no differences in cure rate of survivors. Pre-feeding periods of up to 8 d before infection produced similar results for mice fed enteral formulations compared to nonpurified diet. Contrary to previous reports, the use of Impact did not improve resistance to disease in mice challenged with lethal doses of L. monocytogenes, as compared with mice fed Osmolite HN. Additionally, mice fed Impact, Perative, or nonpurified diet responded similarly to challenge with L. monocytogenes, C. albicans or influenza A. The results indicate that these acute lethal animal models of infectious challenge may be of limited use to distinguish effects of modified nutrient composition of enteral formulas.

Animals↗

Clarithromycin therapy of experimental Treponema pallidum infections in hamsters.

Clarithromycin was shown to be effective therapy for Treponema pallidum infections in hamsters. Clarithromycin therapy was effective when initiated either 1 or 8 days after infection. The delay in initiation of therapy allowed an active infection to develop. The treponemal burden in lymph tissue of treated hamsters was eradicated, as determined by dark-field microscopy and by inoculation of lymph material into susceptible hamsters. Treatments with clarithromycin and the 14-hydroxy metabolite of clarithromycin were equally effective. Therapy with clarithromycin and penicillin was not antagonistic and did not appear to be synergistic when the two drugs were given concurrently. Pharmacokinetic evaluation of clarithromycin in hamsters showed that the doses which produced effective therapy yielded concentrations in serum similar to those routinely achieved in human sera. These findings demonstrate that clarithromycin is effective in treating active or incubating syphilis in the hamster model and could be useful in treating humans.

Animals↗

Efficacy of clarithromycin for treatment of experimental Lyme disease in vivo.

Clarithromycin provided effective therapy against arthritis induced by Borrelia burgdorferi infection in the hamster. In vitro, clarithromycin was at least 1 log more potent than tetracycline against two isolates of B. burgdorferi from human sources, as measured by MICs and 50% inhibitory concentrations. Clarithromycin was effective in preventing the onset of B. burgdorferi-induced arthritis, as determined by several parameters of paw swelling. When administered after the onset of arthritis, clarithromycin therapy reduced the degree of swelling and decreased recovery time. These results suggest that clarithromycin has potential as an effective therapy for Lyme disease.

Animals↗

Functional alterations accompanying a rapid decline in ventilatory function.

In a study of two groups of healthy males matched for age, smoking habits, and duration of follow-up, but differing in the rapidity of decline of FEV1 and/or vital capacity (VC), we measured lung volumes before and after bronchodilator inhalation, forced expiratory flows, diffusion capacity for CO (DLCO), and total respiratory impedance. A discriminant analysis showed that the separation between the two groups was achieved best by DLCO, weight, and FEV1/VC among the smokers and by body height and DLCO among the nonsmokers. The fact that DLCO turns out to discriminate between people with a rapid and a normal spirographic decline in the present group points to the possibility of using this measurement, in combination with FEV1/VC and weight, as a predictor of rapid decline of lung function in middle-aged healthy male smokers.

Adolescent↗

Involvement of synaptosomal neurotransmitter amino acids in audiogenic seizure-susceptibility and -severity of Rb mice.

The involvement of synaptosomal neurotransmitter amino-acids in seizure susceptibility and seizure severity was explored. The amino-acid contents of brain synaptosomes were determined in three sublines of Rb mice differing in their response to an acoustic stimulus: Rb1, clonic-tonic seizure-prone, Rb2, clonic seizure-prone, and Rb3, seizure-resistant. Synaptosomes were prepared from 6 brain areas considered to be involved in seizure activity: olfactory bulbs, amygdala, inferior colliculus, hippocampus, cerebellum, pons-medulla. The steady-state levels of GABA and glycine (Gly), inhibitory amino-acids, of taurine (Tau), an inhibitory neurotransmitter of neuromodulator, of aspartate (Asp) and glutamate (Glu), excitatory amino-acids, as well as of serine (Ser) and glutamine (Gln), two precursors of neurotransmitter amino-acids, were determined by HPLC. Low levels of Tau, GABA, and Ser in hippocampus, Gly in amygdala, Glu in hippocampus, inferior colliculus and pons, Gln and Asp in inferior colliculus appeared to correlate with seizure-susceptibility. GABA and Asp in olfactory bulb, Gln in amygdala, hippocampus and pons, ser in olfactory bulb and pons, appeared to be associated either with seizure-severity or -diversity. A strong involvement of hippocampus (Tau, GABA, Ser, Glu, and Gln) and inferior colliculus (Asp, Glu, Gln) in audiogenic seizure-susceptibility, and of olfactory bulb (GABA, Asp) in seizure-severity and/or -diversity is suggested.

Acoustic Stimulation↗

Activin A induced expression of a fork head related gene in posterior chordamesoderm (notochord) of Xenopus laevis embryos.

A gene family encoding the fork head/HNF-3 domain has been identified in the South African clawed frog, Xenopus laevis. Screening of genomic DNA and gastrula stage derived cDNA libraries with a DNA fragment encoding the Drosophila fork head domain led to the isolation of a number of different clones encoding this motif. While one of the Xenopus fork head sequences, XFD-3, represents the Xenopus counterpart to rat HNF-3 beta, all other sequences encode novel types of fork head related proteins. Here we report on XFD-1, a DNA binding protein which can bind to the HNF-3 alpha target sequence. Analysis of temporal and spatial expression revealed that the gene is activated at blastula stage and that transcripts are localized in a rather thin stripe of cells invaginating the dorsal blastopore lip (organizer) during gastrulation. XFD-1 mRNA is localized within the notochord and, by the end of neurulation, is no longer detectable. In the animal cap assay the gene is activated by incubation with the vegetalizing factor (activin A) but not with bFGF.

Activins↗

The senile lung. Comparison with normal and emphysematous lungs. 1. Structural aspects.

As part of a study of the structural-functional correlations of excised human lungs obtained at autopsy, the parenchyma and peripheral airways were examined by means of morphometric techniques. Among the 30 lungs characterized by the absence of fibrosis, ten differed from the normal and emphysematous lungs by a homogeneous dilatation of the airspaces, in excess of the dimensions predicted on the basis of age. Study of the standard deviations of the mean linear intercepts showed that the airspace dilatation was more regular than in emphysematous lungs; in addition, there was no clear-cut destruction, as estimated from the number of alveolar attachments. These lungs were characterized in addition by an increased thickening of alveolar septa, without inflammation or fibrosis, normal size of the diameter, and reduced density of the membranous bronchioles. Since these lungs were from people older than 60 years, it is assumed that they represent cases of exaggerated airspace enlargement of the aging lung, differing from emphysema by the absence of destruction of alveolar walls. The term "senile lung" is proposed or this condition.

Aged↗

The senile lung. Comparison with normal and emphysematous lungs. 2. Functional aspects.

Senile lungs are characterized by a homogeneous enlargement of the alveolar airspaces, without fibrosis or destruction of their walls. Study of the functional characteristics of excisea senile lungs showed an increase in minimal air and a shift to the left of the elastic recoil pressure-volume curves, less pronounced than in emphysematous lungs. Maximal expiratory volumes and flows were normal. Total lung capacity was not significantly increased, but this may be a consequence of preagonal edema. Comparison of normal, senile, and emphysematous lungs showed a close relationship between recoil pressures and mean linear intercept, Lm, and between forced expiratory volume in 1 s and diameter and density of the membranous bronchioles. It is concluded that airspace enlargement may precede emphysema and may be responsible for changes in lung elasticity. In this respect, senile lungs are an example of the functional changes caused by an isolated airspace enlargement.

Adolescent↗

The mental health of African-American and Caucasian-American women who are homeless.

1. Nurses can use research findings to educate other health professionals about homeless subcultures with attention to specific cultural and socioeconomic needs, as well as to develop interventions for homeless women. 2. Minority women are more susceptible to homelessness as they experience increased poverty levels and are often single mothers. Of all minority women, African-American women are the most vulnerable to physical and psychological illness. 3. In this study, 75% of the subjects had scores on a psychological assessment test that indicated they needed additional psychological testing.

Adolescent↗

[Hantaan virus infection in Twente].

OBJECTIVE: To find out if Hantavirus infection, as a cause of acute renal failure, has been overlooked in the past. To determine if Hantavirus can be found in wild rodents, particularly in red bank voles (Clethrionomys glareolus), living in the area. SETTING: General hospital, Twente area. PATIENTS, MATERIAL AND METHODS: Retrospective selection of patients, hospitalised between 1970 and 1989 with renal failure due to biopsy-proven or clinically probable acute interstitial nephritis of unknown aetiology. Sera from the acute phase of the disease, if still available, or sera taken in 1989 were tested for anti-Hantavirus antibodies. Red bank voles, trapped in the area were tested for Hantaviral antigen and specific antibodies. RESULTS: Out of 12 patients, 10 could be investigated. Anti-Hantavirus antibodies were detected in 5 patients. All patients had very probably acquired the infection in the Twente area. In 4 of 10 red bank voles Hantaviral antigen and specific antibodies were found. CONCLUSION: The findings suggest that Hantavirus infections have been occurring in this area over a long period of time and are underdiagnosed.

Acute Kidney Injury↗