Naturally occurring variants of human T-cell leukemia virus type I Tax protein impair its recognition by cytotoxic T lymphocytes and the transactivation function of Tax

There is a high degree of intraisolate sequence heterogeneity in the tax gene of human T-cell leukemia virus type I (HTLV-I), although the sequence variation between patients is small compared with that of human immunodeficiency virus type 1. In the present study, we investigated whether naturally occurring amino acid substitutions changed the properties of the Tax protein in two respects: first, recognition of the protein by cytotoxic T lymphocytes (CTL), and second, the ability of the Tax protein to transactivate various promoters. We found that (i) all of the observed amino acid substitutions that occur in known CTL epitopes abolished the recognition of the synthetic peptide representing the respective epitope; (ii) these substitutions occurred significantly more frequently in subjects carrying HLA-A2; and (iii) most of the amino acid substitutions severely reduced the ability of Tax protein to transactivate three promoters: the HTLV-I long terminal repeat, the c-fos promoter, and the interleukin-2 receptor alpha chain promoter.

Validating gender-specific defining characteristics of altered sexuality

The authors conducted a retrospective study to validate gender-specific defining characteristics for the proposed nursing diagnosis altered sexuality. An investigator-designed tool was used to collect data from 100 randomly selected members of NANDA. The Fehring method of diagnostic content validity was used to identify major and minor defining characteristics for men and women. The defining characteristics identified and validated encompass all dimensions of human sexuality, and are more concise and descriptive of this human response than those currently in use. Findings of this study will be used to develop a tool for assessment of altered sexuality in a variety of populations and settings.

Production and analysis of transgenic mice with ectopic expression of parvalbumin

Transgenic mice expressing rat parvalbumin under the control of the human metallothionein IIA (MTII A), SV-40 early, and neuron-specific enolase (NSE) promoters were produced. Ectopic expression was analyzed by RNA polymerase chain reaction and RNase protection in combination with immunohistochemistry. From a total of 25 transgenic lines 18 were found to express the transgene. Expression strength and tissue specificity were dependent upon the promoter used and varied considerably among animal lines produced with the same construct. Highest constitutive MT IIA-driven expression was found in lung, liver, heart, and kidney, as well as in brain, and lower amounts of transgene expression were found in spleen, testis, and muscle. Immunohistochemistry of tissue sections of metallothionein-parvalbumin transgenic strain 29 in the non-induced state revealed that ectopic PV mRNA is translated into protein. Short-term induction of the MT IIA promoter by CdSO4 or CdCl2 leads to a shift in tissue specificity and does not increase ectopic expression in tissues where the transgene is active in the noninduced state. As expected the NSE promoter showed highest activity in brain. However, NSE-driven expression could also be detected to various degrees in all investigated tissues. SV-40-dependent PV expression showed no tissue preference and varied considerably among different strains. Except for the observation that the SV-40-PV construct showed lower yields in transgenic production and reduced numbers of positive offspring no obvious impairment of growth or behavior as a consequence of transgenic PV expression could be detected.

Spatiotemporal gait parameters measured using the Bessou gait analyzer in 79 healthy subjects. Influence of age, stature, and gender. Study Group on Disabilities due to Musculoskeletal Disorders (Groupe de Recherche sur le Handicap de l'Appareil Locomoteur, GRHAL)

The Bessou gait analyzer provides quantitative measurements of spatiotemporal gait parameters. The purpose of this study was to determine whether and how these parameters are influenced by age, stature, and gender. Seventy-nine normal individuals (38 males aged 20 to 80 years and 41 females aged 20 to 80 years) were divided into ten-year age groups. Males and females were studied separately. In each subject, the Bessou gait analyzer was used to measure spatiotemporal gait parameters (spatial parameters: stride and step lengths; temporal parameters: cycle, stance and swing durations). Mean walking speed was calculated in each subgroup. In both males and females, all study parameter values were identical for the left and right sides. Females younger than 60 years had shorter stride and step lengths (M: 1.5 +/- 0.2 m; F: 1.3 +/- 0.1; p < 0.001) but faster pace values (M: 104.8 +/- 9.0 cycles/min; F: 115.6 +/- 7.6 cycles/min; p < 0.001) than males, and consequently mean walking speed was similar in females and males (M: 4.8 km/h +/- 0.8 km/h; F: 4.4 km/h +/- 0.6 km/h). In contrast, females older than 60 years walked at the same pace as males and consequently had slower walking speeds. Stride length was correlated with age, stature, and gender. However, age was correlated with stature, and only age and gender had independent effects on gait parameters in the multiple regression analysis. In subjects of similar age and gender, effects of stature may need to be taken into account.

Biological dosimetry after extensive diagnostic x-ray exposure

The yield of chromosome aberrations (dicentric and ring chromosomes) was determined for five patients who had been extensively exposed to diagnostic x rays. Remarkably high aberration yields were obtained for each of them leading to correspondingly high equivalent whole body doses ("biological dosimetry"). The contribution of iodized contrast media and computing tomography to the biologically estimated doses is discussed.

Perineal descent at defecography in women with straining at stool: a lack of specificity or predictive value for future anal incontinence?

OBJECTIVE

To determine (1) whether patients complaining of straining at stool have pelvic floor descent and anal abnormalities similar to those of patients with anal incontinence and (2) whether these patients are prone to develop anal incontinence.

METHODS

To answer the first question we used defecography to study perineal floor position at rest, during maximal contraction of the anal sphincter and during straining, and we performed anorectal manometry in 46 women with straining at stool but without anal incontinence at the beginning of the study, and in 46 women with idiopathic anal incontinence, matched for age. To answer the second question, we performed a 5-year follow-up study to determine whether anal incontinence had developed in those women with straining at stool.

RESULTS

Perineal floor position at rest, during maximal contraction of the sphincter and during straining, resting pressure in the upper part of the anal canal, maximal amplitude and duration of the voluntary contraction were similar in the 46 women with straining at stool and the 46 women with idiopathic anal incontinence. In the follow-up study, 24 of the 46 women with straining at stool were contacted. The incidence of anal incontinence after 5 years was higher among these 24 women than in a control group of 20 women (13 out of 24 versus three out of 20, for women with straining at stool versus controls respectively; P < 0.01). The 13 patients with straining at stool who became incontinent had, at the initial investigation, a lower maximal amplitude of voluntary contraction, greater perineal descent at rest and less elevation of the pelvic floor during maximal contraction of the anal sphincter than the other women (P < 0.05).

CONCLUSION

Women with chronic straining at stool have perineal descent at rest and during straining similar to that of incontinent women. Women with chronic straining are also prone to develop anal incontinence, suggesting that perineal descent at defecography in women with straining at stool may predict future anal incontinence.

Novel tools for the study of development, migration and turnover of nematocytes (cnidarian stinging cells)

The rhodamine derivatives tetramethyl-rhodamine-5/6-maleimide (TROMI) and tetramethyl-rhodamine-6-isothiocyanate (TRITC) were allowed to react with living Hydra vulgaris. The two fluorescent dyes stain the polyps to different degrees, apparently without impairing their viability and behaviour. Concerning nematocytes, TROMI preferentially couples to cytoskeletal elements only of mounted nematocytes whereas TRITC selectively reacts with structural components of cysts of late nematoblasts, which thereafter develop apparently normally into mature nematocytes. Hence TROMI-labelling indicates that nematocytes are mounted and ready for discharge; TRITC-labelling can be used as a tool to investigate the final maturation, migration and installation of nematocytes in Hydra. Together with a new non-fixative method to dissociate Hydra polyps into single, identifiable cells, the two labelling methods allow direct quantitative dynamic studies of nematocyte turnover and open new possibilities of investigating the regulation and the mechanisms of nematocyte supply and migration.

Test time and efficiency of the dynamic strategy in glaucoma perimetry

The dynamic strategy is a perimetric measurement procedure where by the luminance-step sizes are optimized according to physiological data. In contrast to the traditional 4- to 2-dB strategy, the step sizes are not constant but vary between 2 and 10 dB depending on the sensitivity. We examined 40 eyes of 40 glaucoma patients with both the traditional and the dynamic strategy using a modified Octopus 1-2-3 perimeter. A total of 16 visual field locations were examined using both strategies 3 times each in alternation. The order of the initial strategy was randomized. The variance of the three measurements was calculated as a measure of reproducibility. The quantity of presented stimuli was recorded as a measure of test time. After the elimination of starting points, absolute scotomata, and series of fields showing a significant trend during the session, 255 measured locations of 27 series were available for evaluation. The mean number of presentations (indicating test time) was 46% (dynamic strategy versus traditional strategy). The variance of the three measurements depended on the sensitivity. In the normal sensitivity range, the dynamic strategy had a markedly lower variance (58%). For relative defects, the variance was higher (141%-156%). According to a benefit/cost calculation, the efficiency of the dynamic strategy was better in all sensitivity ranges and reached a factor of 3 for high sensitivities. The dynamic strategy is considerably more efficient than the traditional strategy using fixed step sizes.

Control of methicillin-resistant Staphylococcus aureus in a pediatric burn unit

BACKGROUND

Control of methicillin-resistant Staphylococcus aureus (MRSA) is particularly difficult in burn units, which are often cited as sources of hospital-wide MRSA outbreaks. We developed a successful MRSA control program and document here its apparent effectiveness in controlling MRSA transmission in a pediatric burn unit.

METHODS

An MRSA control program that included surveillance culturing, clinician feedback, flexible, site-specific isolation, and a list of known carriers was consistently applied in a pediatric burn unit through a 7-year period. Microbiology reports of MRSA isolates from patients and environmental surfaces and records of all patients from whom MRSA was isolated were reviewed.

RESULTS

During calendar years 1985 through 1991, a total of 991 acutely burned children were admitted to the Boston unit of the Shriners Burns Institute. Forty MRSA cases (4%) were identified. One patient both had MRSA at admission and met our criteria for nosocomial MRSA. Of the remaining 39 patients, 11 had MRSA at admission and 28 had nosocomial MRSA. There were 17 wound infections, two cases of pneumonia, and two bloodstream infections. No deaths were attributed to MRSA sepsis.

CONCLUSION

An MRSA control program including surveillance culturing, clinician feedback, flexible, site-specific isolation, and a list of known carriers is associated with a low rate of nosocomial MRSA in a pediatric burn unit.

[Patient contact supported effectiveness evaluation of legal guidelines on ambulatory care]

A network of about 100 physicians (general practitioners, internists) has been introduced in Lower Saxony, Germany. The participating physicians report on a sample of their patient contacts involving frequent complaints (e.g. vertigo, leg problems, pain due to rheumatic conditions, and gastrointestinal disturbances). The project combines individual, problem-specific patient monitoring with the physicians' estimation of both the conditions under which they conduct their practice and the state of the regional health care system. A standardized questionnaire records sociodemographic variables and major reasons for the patients' visit. It also records data about diagnoses, diagnostic and therapeutic strategies and changes in therapy. In 1993 special attention was given to an assessment of recent health care cost containment legislation and its effects upon the quality of ambulatory medical care. 1400 patient contacts have been reported on in the first two surveys. Results are presented in this article.

[Regulating intraoperative pressure in filtering glaucoma operations with a sterilizable tonometer]

BACKGROUND

Hypotony with shallow or flat chamber and hypertony without filtration are important short-term complications of filtering procedures in glaucoma. Both reflect the difficulty to adjust the tension of the scleral flap in a way that the artificial valve opens at pressures within the therapeutic range. Our aim was to avoid these complications by improving the filling test.

PATIENTS AND METHOD

22 eyes of 21 patients with chronic glaucoma of different etiology underwent a trabeculectomy. After preliminarily fixing the sutures, the anterior chamber was filled until fluid appeared at the rim of the scleral flap. Then, the pressure was measured using a newly developed, sterilizable applanation tonometer. By tightening or loosening the sutures the opening pressure was adjusted to values between 5 and 20 mm Hg.

RESULTS

The IOP at the first postoperative day correlated well with the intraoperative flap opening pressure (correlation coefficient 0.771), but was 20% lower at the average. All cases had a sufficient filtering zone and IOP below 20 mm Hg. At the first day, all chambers were deep. After 2 to 9 days, 4 eyes developed temporarily a shallow chamber (minimum depth: 1 1/2 times corneal thickness). This complication occurred only in eyes with intraoperative pressures of 5 to 10 mm Hg.

CONCLUSION

Intraoperative pressure control during trabeculectomy allows a fairly good determination of the postoperative IOP. Choosing a suitable pressure level (15 to 20 mm Hg), hypotony and shallow chambers should be avoided. Hypertony can be hindered, as well.

Validity of two-dimensional data obtained with the Heidelberg Retina Tomograph as verified by direct measurements in normal optic nerve heads

The Heidelberg Retina Tomograph (HRT) was recently developed to measure two- and three-dimensional parameters of the optic disc. The instrument gives measurement results on an absolute scale; the validity of the scaling has never been proven in the living eye. Eight phakic eyes (eight patients) scheduled for subsequent pars plana vitrectomy were selected for this study. The optic disc was scanned using the HRT. During vitrectomy, the disc was measured directly using a modified retina spatula that had a 2.5-mm scale with a grading of 1/10 mm at the tip. The measurement was recorded with a high-resolution video system adapted to a Zeiss operation microscope. We used a vitrectomy contact lens with a flat surface. First we looked for reference points along the disc margin that could be clearly identified on both images, then we determined the distances between these points. Calculations from HRT data followed according to the software used in this instrument. Calculations from video images were related to the grading of the intraocular scale instrument. As determined using HRT software version 1.08, the mean ratio of HRT distances obtained by direct video measurements was 1.031 (SD, +/- 0.099; SE, +/- 0.035). No significant correlation between the ratio and the ametropia of the eyes could be verified (r = 0.506, P = 0.20). On average, the two-dimensional measurements of the HRT were correct. Furthermore, we used software version 1.07, which does not correct the image size depending on refraction, and found that the mean ratio of HRT distances obtained direct video measurements was 0.985 (SD, +/- 0.108; SE, +/- 0.038).(ABSTRACT TRUNCATED AT 250 WORDS)

Serotyping HIV type 1 by antibody binding to the V3 loop: relationship to viral genotype. WHO Network for HIV Isolation and Characterization

We have investigated whether peptides representing the HIV-1 principal neutralization domain (V3) can be used as antigens in antibody-binding assays to predict the genotypes of the subjects' virus. Serum samples collected from HIV-1-infected subjects from the four WHO-sponsored vaccine evaluation sites (Uganda, Rwanda, Thailand, and Brazil) were characterized by antibody binding to a panel of synthetic V3 peptides that were derived from the consensus sequences of the V3 region of the HIV-1 subgroups according to the env phylogenetic analysis (A-E). An indirect V3 peptide-binding assay was used for primary screening, and a V3 peptide antigen-limiting ELISA was then used as a secondary assay to discriminate cross-reactivity if the screening assay was equivocal. In general, V3 peptide serology could predict HIV-1 genotypes. In sera for which the genotype of the virus was known, peptide assays could predict the correct genotype in approximately 90% of cases for genotypes A, B, C, and E; Ugandan sera of genotype D were more broadly reactive. There was considerable serological cross-reactivity between some HIV-1 genotypes, in particular between A and C, and, to a lesser extent, B and D subtypes. Owing to polymorphism at the crown of the V3 loop, an additional B peptide (B') was required to type Brazilian B genotype sera. These simple assays may help facilitate the determination and distribution of HIV-1 genotypes circulating in populations.

The transactivator gene of human T-cell leukemia virus type I is more variable within and between healthy carriers than patients with tropical spastic paraparesis

Human T-cell leukemia virus type I (HTLV-1) causes T-cell leukemia and tropical spastic paraparesis (TSP) in a minority of infected people, whereas the majority remain healthy. No association between a particular HTLV-I sequence and disease manifestation has been found in previous studies. We studied here the sequence variability of the gene for the HTLV-I Tax protein, which is the dominant target antigen of the very strong cytotoxic T-lymphocyte response to the virus. In HTLV-I infection, the intraisolate nucleotide variability is much greater than the variability between isolates. The predicted protein sequence of Tax was significantly more variable in the healthy seropositive individuals' provirus than in those of the patients with TSP. Thus, tax sequence heterogeneity, rather than the presence of particular sequences, distinguishes healthy HTLV-I-seropositive individuals from patients with TSP.

1H-NMR studies of the natriuretic peptide urodilatin: sequence-specific resonance assignment

The recently discovered 32 amino-acid natriuretic peptide urodilatin was chemically synthesized and subjected to two-dimensional proton nuclear magnetic resonance (NMR) spectroscopy studies in aqueous solution in order to determine the structural state of urodilatin. In contrast to earlier studies on very closely related peptides, such as cardiodilatin (CDD/ANP-99-126) and brain natriuretic peptide (BNP), spectra of urodilatin were extremely well resolved even in millimolar concentration in H2O so that the complete sequence specific resonance assignments could be achieved. No long range NOEs could be detected, except between residues close to the single cystine bond. This leads to the conclusion that urodilatin in aqueous solution is a random coil peptide with the exception of the region around the cystine bond.

Cooperativity and stoichiometry of substrate binding to the catalytic sites of Escherichia coli F1-ATPase. Effects of magnesium, inhibitors, and mutation

The fluorescence of residue Trp beta 331 in beta Y331W mutant Escherichia coli F1-ATPase was used as reporter probe to investigate the effects of magnesium ions, inhibitors, and mutation on substrate (ATP) binding stoichiometry and cooperativity. It was found that Mg2+ is required for catalytic site binding cooperativity. In the absence of magnesium, ATP bound to three independent catalytic sites, each with Kd = 76 microM. In contrast, MgATP bound to three catalytic sites with Kd1 < 50 nM, Kd2 = 0.5 microM, and Kd3 = 25 microM. There was no significant ATPase activity in the absence of Mg2+. Catalysis is therefore correlated with substrate binding cooperativity and the formation of the high-affinity catalytic site 1. Catalytic site 3 had properties similar to those of the isolated beta-subunit nucleotide-binding site. The inhibitors dicyclohexylcarbodiimide and N-ethylmaleimide (in alpha S373C/beta Y331W mutant F1) gave potent inhibition of multisite ATPase activity without significantly affecting MgATP binding stoichiometry or cooperativity. Therefore each seems to selectively attenuate positive catalytic cooperativity. The same conclusions held for the alpha S373F mutation (in alpha S373F/beta Y331W mutant F1). 7-Chloro-4-nitrobenzo-2-oxa-1,3-diazole, however, reduced the catalytic site MgATP binding stoichiometry from three to two, and appears to inhibit catalysis by sterically blocking catalytic site 3.

Seroprevalence of measles- and rubella-specific antibodies among military recruits, Canada, 1991

A study of the seroprevalence of measles- and rubella-specific antibodies among military recruits in Canada in 1991 was undertaken to: 1) determine the proportion of military recruits who are measles and/or rubella seropositive when they enter the military; 2) detect general problems in the immune coverage in the young adult population; and 3) determine the proportion of measles seronegativity attributable to non-response, waning immunity or lack of exposure to either the disease or the vaccine. One initial blood sample was collected from all 399 recruits enrolled in basic training during the month of January 1991, prior to immunization with measles-mumps-rubella vaccine (MMR). Another sample was obtained from 354 of these recruits 3 to 5 weeks following this immunization. Only 18 (4.5%) recruits had negative measles-specific neutralization on the first sample. Only 12 (3.0%) recruits had negative measles-specific EIA on the first sample. All recruits had neutralization titres 40 or higher on the second sample. A total of 43 (10.8%) individuals had negative results for rubella EIA before immunization, 35 of which (81.4%) tested positive on the second sample.

Immunization of patients with rheumatoid arthritis against influenza: a study of vaccine safety and immunogenicity

OBJECTIVE

To address the issues of immunogenicity and local and systemic reactions to vaccination with influenza vaccine in patients with rheumatoid arthritis (RA).

METHODS

One hundred and twenty-six patients with RA were stratified into 3 groups: (1) those with a history of vaccination with influenza vaccine within 24 months who were receiving usual therapy for RA, (2) those receiving usual therapy for RA but without prior vaccine, and (3) those receiving immunosuppressive medication or prednisone > or = 7.5 mg/day, irrespective of their prior immunization status. Within each group, patients were randomized to receive vaccine or placebo. A group of age matched, healthy controls were also vaccinated.

RESULTS

During a one month followup period, adverse reactions occurred with equal frequency among patients with RA and healthy controls. Similar significant increases in titers to the vaccine were seen in all groups of patients with arthritis and in the controls.

CONCLUSION

The potential increase in susceptibility to influenza and death from respiratory illness in patients with RA and the demonstrated safety and immunogenicity of influenza vaccine should require the inclusion of patients with RA in standard immunization programs.