Immune-complex disease: a link between viral infection and sudden infant death?
Explore the source record for details and available documents.
Humans↗
Biomedical subjects
J Peters
Publications and source records attributed to J Peters.
Stereophotogrammetric-controlled pointing device for neurosurgical use.
Explore the source record for details and available documents.
Humans↗
Carcinoma of the uterine cervix associated with schistosomiasis and induced by human papillomaviruses.
OBJECTIVES: To determine the presence of human papillomaviruses (HPVs) in cervical cancer among patients in Tanzania and to ascertain their prevalence in cases associated with schistosomiasis. METHODS: In situ hybridization was applied to 31 carcinomas of the uterine cervix including 10 in which schistosomiasis co-occurred. Twenty-six cases in this series also exhibited koilocytic dysplasia. RESULTS: Twenty-six out of 31 cases revealed a specific hybridization for HPVs with varying density and distribution. A slightly higher labeling of HPV-16 than -18 was demonstrated. All schistosomiasis-associated cancers encoded the papillomaviruses. The 31 patients were predominantly young adults, a fact that reflects sexual activity at a very young age in the ethnic communities of Africa. CONCLUSION: These findings shed new light on the presumed etiologic implication of schistosomiasis in the genesis of cervical cancer. In the absence of HPV, schistosomiasis is not the oncogenic causative agent for carcinoma of the uterine cervix.
Carcinoma, Squamous Cell↗
Morphology and function of the adrenal zona glomerulosa of transgenic rats TGR [mREN2] 27: effects of prolonged sodium restriction.
Heterozygous female transgenic rats for the murine Ren-2 gene (TGR) display a high blood pressure, together with a low kidney and high adrenal renin content. The effects of prolonged sodium restriction on the morphology and secretory activity of adrenal zona glomerulosa (ZG) of TGR and their age- and sex-matched Sprague-Dawley control rats (SDR) were investigated. Under basal conditions, TGR had a moderately hypertrophic ZG, that showed a significantly higher secretion of 18-hydroxylated (18OH) steroids: 18-hydroxy-11-deoxycorticosterone (18OH-DOC), 18-hydroxycorticosterone (18OH-B) and aldosterone (ALDO); ZG cells of TGR showed angiotensin II (AII)-binding site concentrations and ALDO secretory responses to AII similar to those of SDR ZG cells. Prolonged sodium restriction increased plasma ALDO level in both SDR and TGR, and significantly raised the volume of ZG. ZG hypertrophy was due to the increase in both the number and average volume of its parenchymal cells. The secretion of 18OH-steroids was markedly enhanced in both groups of rats; however, in TGR this rise was exclusively due to increases of 18OH-DOC and 18OH-B, while in SDR also ALDO production was enhanced. The yield of non-18OH-steroids was not affected. 11-Dehydrocorticosterone production was not changed in SDR, but doubled in TGR. ZG cells of sodium-restricted SDR and TGR displayed similar increases in their AII-binding site concentration and ALDO secretory response to AII. In conclusion, our present findings confirm that TGR possess a hypertrophic ZG and an elevated secretory capacity o 18OH-steroids, but show only slight differences in ZG and ZG-cell responses to prolonged sodium deprivation.
Animals↗
Molecular basis of human hypertension: the role of angiotensin.
On the basis of recent advances in molecular biology and statistical genetics, it has become possible to search for chromosome regions that contain genes predisposing to hypertension and to directly link specific mutations on candidate genes to hypertension. As the human genome has been extensively mapped, highly informative, polymorphic markers are available, which can be used to detect genes in their proximity with 'hypertensinogenic' alleles. Some of these markers have been shown to be tightly linked to the genes of the renin-angiotensin system. Furthermore, the coding and regulatory regions of the genes encoding for renin, ACE, angiotensinogen and the AT1 receptor have been partially characterized. This provides a basis for further definition of specific polymorphisms within these genes that are of functional importance and that can be used to examine their contribution to the inheritance of primary hypertension. The first studies of these links have already emerged and have been reviewed in this article. Several problems arise in performing such linkage studies in human primary hypertension, however. It is difficult to define the genetic background of heterogeneous, multigenetic and multifactorial diseases such as human hypertension. Extensive studies of population genetics, including the analysis of large numbers of generations and controlled breeding experiments, cannot be performed, for obvious reasons. Blood pressure is not a convenient study trait, because it exhibits great intraindividual variance and also because of the relatively low reliability of just a few indirect measurements obtained under loosely controlled environmental conditions. Twenty-four-hour ambulatory blood pressure measurements may improve such investigations in the near future. Ravogli et al (1990) reported that the 24-hour ambulatory systolic blood pressure is higher in normotensive subjects of hypertensive parents than in normotensive subjects of normotensive parents--a finding that had not been previously reported using the conventional method of measurement. Hypertension as a trait per se is also problematic: its classification (above 140/90 mmHg) is purely artefactual, and its aetiology is highly heterogeneous. Thus, we have to keep in mind that even strong gene effects, if present in only a small subgroup of hypertensives, may not be detected in these studies. Attempts are being made to strengthen the analysis by characterizing physiologically distinct subgroups. In addition, the investigation of intermediate phenotypes, such as plasma parameters, which are more reliable and less subject to variations, may be helpful.(ABSTRACT TRUNCATED AT 400 WORDS)
Angiotensin II↗
Thirteen genes (Cebpb, E2f1, Tcf4, Cyp24, Pck1, Acra4, Edn3, Kcnb1, Mc3r, Ntsr, Cd40, Plcg1 and Rcad) that probably lie in the distal imprinting region of mouse chromosome 2 are not monoallelically expressed.
Seven imprinted genes are currently known in the mouse but none have been identified yet in the distal imprinting region of mouse Chromosome (Chr) 2, a region which shows striking linkage conservation with human chromosome 20q13. Both maternal duplication/paternal deficiency and its reciprocal for distal Chr 2 lead to mice with abnormal body shapes and behavioural abnormalities. We have tested a number of candidate genes, that are either likely or known to lie within the distal imprinting region, for monoallelic expression. These included 3 genes (Cebpb, E2f1 and Tcf4) that express transcription factors, 2 genes (Cyp24 and Pck1) that are involved in growth, 5 genes (Acra4, Edn3, Kcnb1, Mc3r and Ntsr) where a defect could lead to neurological and probably behavioural problems, and 3 genes (Cd40, Plcg1 and Rcad) that are less obvious candidates but sequence information was available for designing primers to test their expression. On/off expression of each gene was tested by reverse transcription-polymerase chain reaction (RT-PCR) analysis of RNA extracted from tissues of mice with maternal duplication/paternal deficiency and its reciprocal for the distal region of Chr 2. None of the 13 genes is monoallelically expressed in the appropriate tissues before and shortly after birth which suggests that these genes are not imprinted later in development. This study has narrowed down the search for imprinted genes, and valuable information on which genes have been tested for on/off expression is provided. Since there is considerable evidence of conservation of imprinting between mouse and human, we would predict that the 13 genes are not imprinted in human. Five of the genes: E2f1, Tcf4, Kcnb1, Cd40 and Rcad, have not yet been mapped in human. However, because of the striking linkage conservation observed between mouse Chr 2 and human chromosome 20, we would expect these genes to map on human chromosome 20q13.
Alleles↗
Bone pate repair of the eroded incus--five years on.
Seventy-four patients undergoing bone pate repair of the long process of the incus as part of a tympanoplasty are presented. Mean follow-up time was 66 months (range 12-143 months). Hearing results are averaged over the frequencies 500, 1000, 2000 and 4000 Hz. Thirty-two per cent of the patients had hearing thresholds better than 30 dB pre-operatively. A significant improvement in hearing was seen (p < 0.001). The data were also analysed to assess the effect of the pre-operative state of the tympanic membrane on the final result. The pre-operative condition of the tympanic membrane was either perforated (35 ears) or atrophic (33 ears). Six tympanic membranes were intact but these were excluded from the final results. No difference in hearing result was found between patients who had an ossicular repair in combination with either a perforated tympanic membrane repair or an atrophic membrane repair. Average hearing gain in the perforated group was 13 dB, in the atrophic group 9 dB and in the intact group 7 dB.
Adolescent↗
In-vitro activity of oxazolidinones against Mycobacterium avium complex.
Options for treating disseminated Mycobacterium avium complex (MAC) disease have improved. However, efficacy is not always certain, resistance is common and rapidly bactericidal agents would improve efficacy and prevent resistance. Certain oxazolidinones were tested against MAC strains and inhibited growth at expected serum concentrations or lower. Activity correlated with hydrophobicity and one agent was bactericidal at concentrations two to five times greater than the MIC.
Amikacin↗
Low-frequency spectral power of heart rate variability is not a specific marker of cardiac sympathetic modulation.
BACKGROUND: Heart rate variability in the frequency domain has been proposed to reflect cardiac autonomic control. Therefore, measurement of heart rate variability may be useful to assess the effect of epidural anesthesia on cardiac autonomic tone. Accordingly, the effects of preganglionic cardiac sympathetic blockade by segmental epidural anesthesia were evaluated in humans on spectral power of heart rate variability. Specifically, the hypothesis that cardiac sympathetic blockade attenuates low-frequency spectral power, assumed to reflect cardiac sympathetic modulation, was tested. METHODS: Ten subjects were studied while supine and during a 15-min 40 degrees head-up tilt both before and after cardiac sympathetic blockade by segmental thoracic epidural anesthesia (sensory block: C6-T6). ECG, arterial pressure, and respiratory excursion (Whitney gauge) were recorded, and a fast-Fourier-transformation was applied to 512-s data segments of heart rate derived from the digitized ECG at the end of each intervention. RESULTS: With cardiac sympathetic blockade alone and the subjects supine, both low-frequency (LF, 0.06-0.15 Hz) and high-frequency (HF, 0.15-0.80 Hz) spectral power remained unchanged. During tilt, epidural anesthesia attenuated the evoked increase in heart rate (+11.min-1 +/- 7 SD vs. +6 +/- 7, P = 0.024). However, while during tilt cardiac sympathetic blockade significantly decreased the LF/HF ratio (3.68 +/- 2.52 vs. 2.83 +/- 2.15, P = 0.041 vs. tilt before sympathetic blockade), a presumed marker of sympathovagal interaction, absolute and fractional LF and HF power did not change. CONCLUSIONS: Although preganglionic cardiac sympathetic blockade reduced the LF/HF ratio during tilt, it did not alter spectral power in the LF band during rest or tilt. Accordingly, low-frequency spectral power is unlikely to specifically reflect cardiac sympathetic modulation in humans.
Adult↗
Chronic dexamethasone treatment suppresses hypertension development in the transgenic rat TGR(mREN2)27.
INTRODUCTION: The transgenic rat TGR(mREN2)27 is a monogenetic rat model in hypertension research. Integration of mouse Ren-2 gene into the rat genome led to fulminant hypertension despite suppressed plasma and kidney renin concentrations. Renin is highly expressed in extrarenal tissues, especially throughout the adrenal cortex. AIMS AND METHODS: Because plasma and urinary corticosteroid concentrations are elevated during the development of hypertension in these rats, we investigated the effect of dexamethasone on blood pressure, adrenal renin and steroid metabolism. RESULTS: A daily injection of 100 micrograms/kg dexamethasone for 8 weeks was capable of suppressing the development of hypertension in the transgenic rats. The same regimen did not alter blood pressure in Sprague-Dawley control rats. Plasma concentrations of adrenocorticotrophic hormone (ACTH)-dependent steroids (corticosterone and 18-hydroxydeoxycorticosterone) decreased markedly in both strains treated with dexamethasone, but more pronouncedly in transgenic rats. Surprisingly, plasma aldosterone concentrations increased exclusively in the transgenic rats, and not in control rats, treated with dexamethasone. The decrease in corticosterone and 18-hydroxydeoxycorticosterone production was accompanied by a decrease in the abundance of the messenger RNA (mRNA) encoding the rate-limiting enzyme in steroidogenesis (P450scc cholesterol side-chain cleavage) and a decrease in the mRNA encoding P450c11 beta (11 beta-hydroxylase). The increase in aldosterone was accompanied by a massive increase in the abundance of the mRNA encoding zona glomerulosa-specific P450c11AS (aldosterone synthase), which was not increased in control rats. CONCLUSION: We conclude that ACTH-dependent steroids other than the mineralocorticoid aldosterone are responsible for the development of hypertension in the transgenic rat.
Adrenal Glands↗
Report of the second international workshop on human chromosome 14 mapping 1994.
Explore the source record for details and available documents.
Chromosome Mapping↗
Clinical isolates of Mycobacterium simiae in San Antonio, Texas. An 11-yr review.
During a period of 11 yr (1983-1993) 137 clinical isolates of Mycobacterium simiae obtained from 75 patients were identified in a University hospital in San Antonio, Texas. One hundred twenty-eight isolates (93%) were from a pulmonary source, four (3%) from blood, and five from other sites including skin, urine, lymph node, bone marrow, and brain. Of 62 evaluable patients, six (10%) had definite infection, nine (14%) had probable disease, and 48 (76%) were thought to be colonized. During the last 2 yr of the study (1992 and 1993), M. simiae became the second most frequently isolated nontuberculous mycobacterium at this institution surpassed only by Mycobacterium avium complex. There are limited data about effective treatment for this multidrug-resistant organism. New macrolides, quinolones, ethambutol, clofazimine, and aminoglycosides are promising therapeutic agents.
AIDS-Related Opportunistic Infections↗
Factors influencing smoking behavior in Hong Kong primary schoolchildren: targets for prevention.
The uptake of smoking by children and factors influencing such behavior, although well documented in the West, have not been studied in the Asia-Pacific region. A cross-sectional survey was carried out on 3,521 children, aged 8-11 years living in two districts of Hong Kong. Knowledge, attitude and behavior related to smoking and sociodemographic data were obtained from questionnaires completed by parents and children. Eleven percent of boys and 5 percent of girls were ever-smokers, 5 percent of all eight-year-olds and 21 percent of 11-year-olds. Believing that parents will not interfere with their smoking (adjusted odds ratio 5.52; 95% confidence interval 2.72, 11.18), living with family members who smoke (1.72; 1.33, 2.23), and having a positive attitude to smoking (4.13; 1.43, 11.98) were factors predictive of ever-smokers. Experimentation with smoking is a major health risk for primary school children in Hong Kong and indicates failure of current smoking prevention programs. Effective culture-specific programs to counteract risk factors and with continuing evaluation are urgently needed; they should be based on information from appropriately-designed epidemiological studies.
Child↗
Primary structure of the thermosome from Thermoplasma acidophilum.
The thermosome, a chaperonin from the archaebacterium Thermoplasma acidophilum, consists of two subunits (M(r) 58,000 and 60,000) which assemble into a cylindrical complex of pseudo eight-fold rotational symmetry. The sequences of the two subunits are approximately 60% identical to each other and to TF55 from Sulfolobus shibatae, and are 30-40% identical to the subunits of the TCP1 containing ring complex (TRiC) from the eukaryotic cytosol. A dendrogram of this family of chaperonins contains eight eukaryotic branches of TRiC subunits and one archaebacterial branch of thermosome subunits. Alignment of thermosome/TRiC sequences with eubacterial and eukaryotic Hsp60 sequences reveals a statistically significant similarity in two large N- and C-terminal blocks of sequence. Based on this alignment and on the recently published crystal structure of GroEL, we propose that subunits of the thermosome/TRiC family of chaperonins have a similar equatorial domain and overall domain topology as GroEL but differ in the structure of the apical domain.
Amino Acid Sequence↗
Seminal vesicle abscess: a case report and review of literature.
Seminal vesicle abscess, a rare urologic entity, is usually diagnosed with computerized tomography (CT) scan. We report a case of seminal vesicle abscess that required a transrectal ultrasonography to confirm the diagnosis. An analysis of 20 cases of seminal vesicle abscess reported in the literature is also reviewed.
AIDS-Related Opportunistic Infections↗
Breast Cancer Genetics: Relevance to Oncology Practice.
Our knowledge of genetic mechanisms involved in cancer initiation, promotion, and progression recently has expanded. In order to benefit from this expansion and to apply genetic discoveries to current protocols for prevention, screening, diagnosis, treatment, prognosis, and monitoring for minimal residual disease, a working knowledge must be developed of the genetic principles, oncogenes, tumor suppressor genes, and genetic models of carcinogenesis. Genetic susceptibility testing for cancer soon will be introduced into oncology practice through established familial risk counseling programs, and the oncologist must be prepared to address the medical, ethical, legal, economic, psychological, and social issues that accompany this testing.
Journal Article↗
[Microbial resistance to formaldehyde. III> Dependence of the microbial effect on Staphylococcus aureus, Enterococcus faecium and spores of Bacillus stearothermophilus on temperature].
Temperature dependence of microbicidal efficacy of formaldehyde was examined with suspension tests (pH 7.0). Test germs were Staphylococcus aureus, Enterococcus faecium and spores of Bacillus stearothermophilus. The methodology was nearly the same as in previous investigations (5, 7). At given exposure periods and temperatures formaldehyde concentrations necessary to produce a microbicidal effect of log (N/N0) = -4.0 (concentrations of equal efficacy) were determined. N and N0 represent the numbers of colony-forming units in suspensions with and without formaldehyde, respectively. On rectangular graphic representation with the reciprocal value of absolute temperature on the abscissa and with the logarithm of the formaldehyde concentration on the ordinate, the formaldehyde concentrations of equal efficacy fitted straight lines. Lines referring to different exposure periods nearly paralleled each other. With increasing exposure periods the steepness of the lines decreased slightly. This effect was most pronounced with Staphylococcus aureus as a test germ. The ratio of formaldehyde concentrations of equal efficacy for exposure periods of 120 minutes at 20 degrees C and 30 degrees C, respectively, was 3.1:1 with Staphylococcus aureus, and 2.8:1 with Enterococcus faecium. The corresponding ratio obtained with spores of Bacillus stearothermophilus and referring to 60 degrees C and 70 degrees C, respectively, was 3.6:1. The logarithms of these ratios decreased with temperature in the same measure as the pertinent absolute temperatures increased. On the basis of the previously presented three-dimensional model of the relations between concentration, period of action and efficacy of microbicidal agents, it could be shown that deviations of the results from a linear and parallel course reflect an inconstant concentration exponent. When low formaldehyde concentration, long exposure period and "high" temperature coincide, the efficacy of formaldehyde is lower than calculated for a linear and parallel course of the relation.
Drug Resistance, Microbial↗
Dynamic support of the human longitudinal arch. A biomechanical evaluation.
This study was designed to evaluate the dynamic support provided to the human longitudinal arch by the leg muscles active in the stance phase of gait and by the plantar aponeurosis. Ten fresh adult cadaveric specimens were mounted in a materials testing machine. The tendons of the posterior tibialis, flexor digitorum longus, flexor hallucis longus, peroneus longus, peroneus brevis, and Achilles tendon were attached to force transducers. Plantar loads of 0, 350 and 700 N were applied, and the tendons were tensioned individually. The Achilles tendon was tensioned an amount equal to the plantar load; the posterior tibialis, flexor digitorum longus, flexor hallucis longus, peroneus longus, and peroneus brevis were tensioned a fractional amount (depending on the proportion of the cross-sectional area to the gastrocsoleus complex). The angular relationships between the first metatarsal, navicular, and talus were recorded using a 3-dimensional movement analysis system. An additional series of measurements was obtained by positioning the ankle plantarflexed 10 degrees under a plantar load of 350 N. Dorsiflexing the toes with the ankle in a neutral position and loading the foot to 350 N and 700 N permitted an evaluation of the effect of the plantar aponeurosis. The plantar aponeurosis, via dorsiflexion of the toes, contributed the most significant arch support in the sagittal plane with a 3.6 degrees increase between the first metatarsal and talus at 350 N and a 2.3 degrees increase at 700 N. The posterior tibialis tendon consistently provided arch support at plantar loads of 350 N and 700 N. The peroneus longus consistently abducted the forefoot in the transverse plane at 350-N and 700-N load levels. The study provides further insight into the dynamic supporting and deforming forces of the longitudinal arch.
Biomechanical Phenomena↗