Functional Analysis of six novel ORFs on the left arm of Chromosome XII of Saccharomyces cerevisiae reveals three of them responding to S-starvation

Six novel Open Reading Frames (ORFs) located on the left arm of the chromosome XII (YLL061w, YLL060c, YLL059c, YLL058w, YLL057c and YLL056c) have been analysed using either short-flanking homology (SFH) or long-flanking homology (LFH) gene replacement. Sporulation and tetrad analysis showed none of these ORFs to be essential for vegetative growth. The standard EUROFAN growth tests failed to reveal any obvious phenotypes resulting from deletion of each of the ORFs. Bioinformatic analysis revealed that YLL061w is probably an amino acid permease for S-methylmethionine and that YLL060c encodes a glutathione transferase which is involved in cellular detoxification, while YLL058w may play a role in sulphur-containing amino-acid metabolism, YLL057c in sulphonate catabolism and YLL056c in stress response. The transcription of three ORFs (YLL061w, YLL057c and YLL056c) has been shown to increase more than 10-fold under sulphate starvation. Replacement cassettes, comprising the kanMX marker flanked by each ORF's promoter and terminator regions, were cloned into pUG7. All the cognate clones, were generated using direct PCR products amplified from genomic DNA or using gap-repair. All clones and strains produced have been deposited in the EUROFAN genetic stock centre (EUROSCARF, Frankfurt).

Treatment failure with the use of ciprofloxacin for gonorrhea correlates with the prevalence of fluoroquinolone-resistant Neisseria gonorrhoeae strains in Bangladesh

Although ciprofloxacin is one of the recommended drugs of choice for the treatment of gonorrhea, in vitro resistance to this drug has been observed in surveillance studies and case reports from many parts of the world, including Bangladesh. However, to our knowledge, there have been no prospective studies of the correlation between in vitro response to the drug and treatment outcome. Therefore, a prospective study of 217 female sex workers in Dhaka, Bangladesh, was conducted to examine the correlation between the in vitro response of Neisseria gonorrhoeae and the outcome of ciprofloxacin treatment. Overall, 37.8% of the gonococcal isolates recovered from female sex workers were resistant to ciprofloxacin, and there was a good correlation between in vitro resistance and treatment failure. These findings suggest that in vitro resistance to ciprofloxacin is predictive of clinical treatment failure in patients with gonorrhea.

Does the relation of blood pressure to coronary heart disease risk change with aging? The Framingham Heart Study

BACKGROUND

We examined the relative importance of diastolic (DBP), systolic (SBP) and pulse pressure (PP) as predictors of coronary heart disease (CHD) risk in different age groups of Framingham Heart Study participants.

METHODS AND RESULTS

We studied 3060 men and 3479 women between 20 and 79 years of age who were free of CHD and were not on antihypertensive drug therapy at baseline. Cox regression adjusted for age, sex, and other risk factors was used to assess the relations of BP indexes to CHD risk over a 20-year follow-up. In the group <50 years of age, DBP was the strongest predictor of CHD risk (hazard ratio [HR] per 10 mm Hg increment, 1.34; 95% CI, 1.18 to 1.51) rather than SBP (HR, 1.14; 95% CI, 1.06 to 1.24) or PP (HR, 1.02; 95% CI, 0.89 to 1.17). In the group 50 to 59 years of age, risks were comparable for all 3 BP indexes. In the older age group, the strongest predictor of CHD risk was PP (HR, 1.24; 95% CI, 1.16 to 1.33). When both SBP and DBP were considered jointly, the former was directly and the latter was inversely related to CHD risk in the oldest age group

CONCLUSIONS

With increasing age, there was a gradual shift from DBP to SBP and then to PP as predictors of CHD risk. In patients <50 years of age, DBP was the strongest predictor. Age 50 to 59 years was a transition period when all 3 BP indexes were comparable predictors, and from 60 years of age on, DBP was negatively related to CHD risk so that PP became superior to SBP.

Unusual presentations in myositis ossificans progressiva. A case report

Myositis ossificans progressiva is a rare connective tissue disorder. We present here a case of myositis ossificans progressiva with some unusual presentations and associated congenital skeletal anomalies that are reported very infrequently in the literature. The case report highlights the importance of early diagnosis in a case of rapidly progressive myositis ossificans progressiva.

Uric acid mediates photodynamic inactivation of caprine alpha-2-macroglobulin

Uric acid (2,6,8 trioxopurine), the end product of purine metabolism in mammalian systems, has shown a wide range of antioxidant properties including scavenging of hydroxyl radical and singlet oxygen. In this study we show that in the presence of visible light, uric acid disrupted caprine alpha-2-macroglobulin (alpha(2) M) structure and antiproteolytic function in vitro. Proteinase cleaves the bait region of caprine inhibitor inducing major conformational changes and entrapping the enzyme within its molecular cage. In contrast to native alpha(2) M, modified antiproteinase lost half of its antiproteolytic potential within 4 hours of uric acid exposure. The changes in uv-absorption spectra of the treated protein suggested possible spatial rearrangement of subunits or conformational change. Analysis of the mechanism by which alpha(2) M was inactivated revealed that the process was dependent on generation of superoxide anion and hydrogen peroxide. Our findings suggest that antiproteolytic activity of caprine alpha(2) M could be compromised via oxidative modification mediated by uric acid. Moreover, low concentrations of alpha(2) M were found to stimulate superoxide production by some unknown mechanism.

Suspected caffeine and ephedrine toxicosis resulting from ingestion of an herbal supplement containing guarana and ma huang in dogs: 47 cases (1997-1999)

OBJECTIVE

To describe the clinical signs following ingestion of an herbal supplement containing guarana and ma huang in dogs, estimate minimum dose at which clinical signs of toxicosis and death were reported, and evaluate treatment options.

DESIGN

Retrospective study.

ANIMALS

47 dogs with evidence of ingestion of an herbal supplement containing primarily guarana and ma huang.

PROCEDURE

Records of dogs that had ingested an herbal supplement containing ma huang and guarana between July 1997 and October 1999 were retrieved from the National Animal Poison Control Center database. Data were retrieved and reviewed regarding signalment, dose ingested, clinical signs, laboratory test results, treatment, and final outcome. Cases were assessed by staff veterinarians as toxicosis or suspected toxicosis on the basis of strength of evidence supporting a diagnosis.

RESULTS

Most dogs (80%) developed clinical signs of toxicosis within 8 hours of ingestion, and clinical signs persisted for up to 48 hours. Hyperactivity, tremors, seizures, and behavior changes were reported in 83% of dogs; other signs included vomiting (47%), tachycardia (30%), and hyperthermia (28%). Seventeen percent of the dogs died or were euthanatized. Estimated doses of guarana and ma huang ranged from 4.4 to 296.2 mg/kg (1.98 to 133.2 mg/lb) and 1.3 to 88.9 mg/kg (0.58 to 40.0 mg/lb) of body weight, respectively; minimum dose at which death was reported was 19.1 mg of guarana/kg (8.7 mg/lb) and 5.8 mg of ma huang/kg (2.6 mg/lb).

CONCLUSIONS AND CLINICAL RELEVANCE

Accidental ingestion of herbal supplements containing primarily guarana and ma huang in dogs can lead to a potentially lethal condition that may require prompt detoxification and supportive treatment for several days. Most dogs recovered with supportive treatment.

Early responses to Salmonella typhimurium infection in mice occur at focal lesions in infected organs

Salmonella typhimurium causes an invasive disease in mice that has similarities to human typhoid, with key roles for cytokines and possibly also inducible nitric oxide synthase (iNOS), in mediating host responses to infection. In this paper we demonstrate that iNOS mRNA, protein and enzyme activity is induced within spleens and livers of infected mice as early as 5 h post-infection. Immunohistochemistry and in situ hybridization indicated that iNOS expression occurs predominantly in macrophages in localized, discrete foci in the infected organs. iNOS activity in spleen and liver was not detectable in uninfected control mice. The presence of mRNA encoding pro-inflammatory cytokines (TNFalpha, IL-1beta and IFNgamma) in infected organs was measured using RT-PCR, all three being present from 2 h post-infection onwards, but not before. These data show that there is a very early host response to S. typhimurium infection in mice, limited to foci within the infected organs.

SUMO-1 modification of bovine papillomavirus E1 protein is required for intranuclear accumulation

The E1 protein is a multifunctional, origin-binding helicase that is essential for replication of papillomaviruses. Recently, bovine papillomavirus E1 was shown to be post-translationally modified by the addition of the SUMO-1 polypeptide. Here we show that the site of sumoylation maps to lysine residue 514. This lysine and the flanking sequences are well conserved in human papillomavirus (HPV) E1 proteins. Both HPV1a and HPV18 E1 proteins are substrates for sumoylation in vitro, which is consistent with this modification being a general property of E1 proteins. Mutations, which impair the sumoylation of bovine papillomavirus E1, prevent normal nuclear accumulation of E1 with a concomitant loss of replication capacity. These results suggest that sumoylation plays a role in nuclear transport and could regulate the E1 replication function by controlling access to the nuclear replication domains.

Indomethacin induced psychosis

Indomethacin is a commonly prescribed non-steroidal anti-inflammatory drug. While its adverse effects on gastrointestinal and renal systems are well described, its central nervous system effects are less well known. This case report describes an elderly man, prescribed indomethacin for gout, who presented with psychosis.

Adult Kawasaki disease

Kawasaki disease was first described from Japan in 1967. Most of the patients reported have been under 3 years of age. We are reporting a typical case of Kawasaki disease in an adult Yemeni male, who had all criteria for diagnosis. Additionally our patient had tricuspid regurgitation as well as tricuspid valve endocarditis, which is only rarely reported in literature. We also noted a rise in monocyte and eosinophil count up to 10%, which may have pathophysiologic significance in this disease. At two year follow up our patient had persistent right bundle branch black which he had developed during the course of his illness. Mortality of the disease is related to cardiac complications especially coronary arteritis and aneurysms in children. In adults too once diagnosis is established patients should be followed for a long period of time to look for any possible cardiac complications.

Polyclonal-antibody-mediated insolubilization and stabilization of papain

Antisera raised in rabbits against native iodoacetamide- and iodoacetic acid-modified papain contained precipitating and non-inhibitory antibodies. Papain could be insolubilized as enzyme-antibody adducts with the gamma-globulin fraction derived from the antiserum. Two insolubilized papain preparations, designated A and B, with low and high antibody/enzyme ratios, respectively, exhibited high enzyme activity and markedly enhanced thermal and denaturant stabilities. However, papain antibody adduct B was superior in activity and stability over preparation A. The usefulness of immobilized papain in biopharmaceutical and other industries is also discussed.

Comparative molecular analysis of erythromycin-resistance determinants in staphylococcal isolates of poultry and human origin

The ermA, ermB, ermC and msrA/msrB genes were detected in multidrug-resistant Staphylococcus spp. strains by PCR. Among 25 human clinical staphylococcal isolates the ermA, ermB, ermC and the msrA/msrB genes were detected in 88, 72, 4 and 100% of the strains, respectively. Among 24 poultry isolates the ermA, ermB, ermC and the msrA/msrB genes were detected in 100, 16.6, 50 and 12.5% of the strains, respectively. The ermA gene was found exclusively on the chromosome, whereas the ermC gene was found on 2.4-4.2 kb plasmids. Restriction fragment length polymorphism (RFLP) analysis of the ermA gene with Eco RI revealed five patterns (25.0, 21.0, 10.5, 6.2 and 4. 8 kb) for the clinical strains and two (8.0 and 6.2 kb) for the poultry strains. The 6.2 kb RFLP pattern, in both the poultry and human clinical isolates, indicates a common lineage for the ermA gene.

Guillain-barre syndrome

Guillain-Barre syndrome is an acute, or more often, a subacutely evolving paralytic disease of unestablished etiology. The condition is often designated as the Landy-Guillain-Strohl syndrome in recognition of the description provided by Landy in 1859 and again in 1916 by Guillain, Barre and Strohl. The pathogenesis and specific therapy in this condition remains imperfectly defined. The diagnosis is usually clinical with supportive laboratory tests. In this syllabus, we review the diagnostic criteria in Guillain-Barre syndrome and current therapies in the acute management followed by presentation of the acute management protocol used in the Neurosciences Department at the Riyadh Armed Forces Hospital.

Characterization of erythromycin-resistant methylase genes from multiple antibiotic resistant Staphylococcus spp isolated from milk samples of lactating cows

OBJECTIVE

To isolate and characterize erythromycin-resistant methylase genes in multiple-antibiotic resistant staphylococci isolated from milk samples.

ANIMALS

300 lactating cows.

PROCEDURE

23 erythromycin-resistant staphylococci were isolated from milk samples of 300 lactating cows. The prevalence of erythromycin-resistant methylase (erm) genes, ermC and ermA genes, and the multicomponent macrolide efflux pump in staphylococci msrA genes were identified and characterized by use of multiplex polymerase chain reaction (PCR), Southern hybridization, restricted fragment length polymorphism (RFLP) analysis, and dot-blot hybridization.

RESULTS

Biochemical characterization indicated that 3 of 23 (13%) isolates were coagulase-positive Staphylococcus aureus, and the rest were coagulase-negative. Multiplex PCR resulted in amplification of a 520-base pair (bp) region of the ermC gene from the cell lysates of a strain of S simulans M-21 and S sciuri M-28. The ermC gene in both isolates was found on a 3-kilobase plasmid. The ermA gene was found on the chromosome of 21 isolates, and 6 RFLP patterns were observed. None of the isolates harbored the msrA gene.

CONCLUSIONS

Erythromycin-resistant Staphylococcus spp isolated from milk samples of lactating cows may serve as reservoirs of erm genes homologous to those described in human isolates. However, the chromosomal insert patterns and prevalence of these genes, the sizes of plasmids harboring the genes, and the number of inserts of the genes (copy number) may differ from that of human isolates.

A retrospective study of low-vision cases in an Indian tertiary eye-care hospital

PURPOSE

To obtain data on the characteristics of low-vision patients seen at a tertiary eye care hospital in India.

METHODS

Records of 410 patients were retrospectively reviewed at the Centre for Sight Enhancement, L.V. Prasad Eye Institute, Hyderabad, India. Patient underwent a comprehensive clinical low-vision examination. Data obtained included age, gender, consanguinity, visual acuity, visual fields, ocular conditions causing low vision and types of low-vision devices and methods prescribed.

RESULTS

Two hundred and ninety seven (72%) of 450 patients were male. One-fifth were in the 11-20 years age group (21%). Visual acuity in the better eye was < 6/18-6/60 in almost half these patients (49.3%). One hundred and twenty two patients (29.9%) referred with a visual acuity of > or = 6/18, either had difficulty in reading normal print or had restricted visual fields. The main causes for low vision were: retinitis pigmentosa (19%), diabetic retinopathy (13%), Macular diseases (17.7%), and degenerative myopia (9%). Visual rehabilitation was achieved using accurate correction of ametropia (174 patients), approach magnification (74 patients) and telescopes (45 patients) for recognising faces, watching television and board work. Spectacle magnifiers (187 patients), hand/stand magnifiers (9 patients), closed-circuit television (3 patients), overhead illumination lamp (143 patients) and reading stand (24 patients) were prescribed for reading tasks. Light control devices (146 patients) were used for glare control, and cane (128 patients) and flashlight (50 patients) for mobility. Patients were trained in activities to improve their daily living skills, (54 patients); counselled in environmental modification (144 patients) and ancillary care (63 patients) for educational and vocational needs.

CONCLUSION

Data obtained from this study elucidates the characteristics of low-vision patients. This information is likely to help in the development of appropriate low vision services.

Oestrogen receptor expression in normal breast epithelium

Higher levels of oestrogen receptor (ER) expression in normal breast epithelium may compound the increase in breast cancer risk seen with prolonged estrogen exposure. In prior studies, we have used immunohistochemical ER assays on fresh frozen samples of benign breast tissue. Future studies will be more feasible on paraffin-embedded samples, and newer, more sensitive antibodies are now available. We examined 30 samples of paraffin-embedded breast epithelium from postmenopausal women with two antibodies, 6F11 and TE111. We find that the median labelling indices for ER are significantly higher using these antibodies, compared with previous results. The threshold for ER positivity will, therefore, have to be reset in future studies, since there are still many issues that remain to be resolved in this area.

Improved diffusion methods for nitrogen and 15nitrogen analysis of Kjeldahl digests

Simple methods are described that permit the use of either H3BO3 indicator solution or acidified filter disks to collect NH3 liberated by treatment of Kjeldahl digests with NaOH. These methods incorporate modifications to improve reliability, analytical capacity, and convenience. A semimicro digest was diluted to 25 mL with deionized water, and a 10 mL aliquot, containing up to 4 mg N (150 microg N for diffusions into acidified disks), was transferred to a shell vial, which was placed inside a 473 mL (1 pint) Mason jar containing 10 mL 10N NaOH. The NH3 liberated by overturning the vial was collected after 12 to 48 h at ambient temperature, or after 4 h at 45 to 50 degrees C on a hotplate, for quantitative and/or isotope-ratio analyses. With either H3BO3 indicator solution or acidified filter disks, recovery of diffused N was quantitative. Isotope-ratio analyses of diffused N from 15N-labeled chemical, plant, and soil samples were within 3% of analyses using steam distillation.

Plasmid rolling-circle replication: recent developments

It is now well established that a large majority of small, multicopy plasmids of Gram-positive bacteria use the rolling-circle (RC) mechanism for their replication. Furthermore, the host range of RC plasmids now includes Gram-negative organisms as well as archaea. RC plasmids can be broadly classified into at least five families, individual members of which are spread among widely different bacteria. There is significant homology in the basic replicons of plasmids belonging to a particular family, and there is compelling evidence that such plasmids have evolved from common ancestors. Major advances have recently been made in our understanding of plasmid RC replication, including the characterization of the biochemical activities of the plasmid initiator proteins and their interaction with the double-strand origin, the domain structure of the initiator proteins and the molecular basis for the function of single-strand origins in plasmid lagging strand synthesis. Over the past several years, there has been a 'renaissance' in studies on RC replication as a result of the discovery that many plasmids replicate by this mechanism, and studies in the next few years are likely to reveal new and novel mechanisms used by RC plasmids for their regulated replication.

5-Hydroxytryptophan toxicosis in dogs: 21 cases (1989-1999)

OBJECTIVE

To determine epidemiologic characteristics, clinical findings, and treatment outcome of 5-hydroxytryptophan (5-HTP) toxicosis in dogs.

DESIGN

Retrospective study.

ANIMALS

21 dogs with evidence of accidental 5-HTP ingestion.

PROCEDURE

Information was retrieved from the National Animal Poison Control Center database. Records of dogs ingesting 5-HTP between January 1989 and February 1999 were reviewed for information on signalment, dose ingested, clinical signs (onset, severity, duration), treatments administered, and outcome.

RESULTS

Clinical signs of toxicosis developed in 19 of 21 (90%) dogs. Neurologic signs included seizures (9 dogs), depression (6), tremors (5), hyperesthesia (5), and ataxia (4). Gastrointestinal tract signs included vomiting or diarrhea (12 dogs), signs of abdominal pain (3), and hypersalivation (2). Other clinical signs were hyperthermia (7 dogs) and transient blindness (3). Three dogs died. No important clinical laboratory or necropsy findings were reported. The doses of 5-HTP ingested ranged from 2.5 to 573 mg/kg (1.1 to 260 mg/lb) of body weight; the minimum toxic dose reported in our study was 23.6 mg/kg (10.7 mg/lb), and the minimum lethal dose was 128 mg/kg (58.1 mg/lb). Onset of signs ranged from 10 minutes to 4 hours after ingestion, and signs lasted up to 36 hours. Of 17 dogs with clinical signs of toxicosis that received treatment, 16 recovered; treatment consisted of decontamination, seizure control, thermoregulation, fluid therapy, and supportive care.

CONCLUSIONS AND CLINICAL RELEVANCE

Ingestion of 5-HTP in dogs can result in a potentially life-threatening syndrome resembling serotonin syndrome in humans, which requires prompt and aggressive care.