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S Walter

Publications and source records attributed to S Walter.

At least 91 records · Page 5Linked to original sources
PubMed1999

Reliability of the Canadian emergency department triage and acuity scale: interrater agreement.

STUDY OBJECTIVE: To determine the rate of interobserver reliability of the Canadian Emergency Department Triage and Acuity Scale (CTAS). METHODS: Ten physicians and 10 nurses were randomly selected to review and assign a triage level on 50 ED case summaries containing presenting complaint, mode of arrival, vital signs, and a verbatim triage note. The rate of agreement within and between groups of raters was determined using kappa statistics. One-way, 2-way analysis of variance (ANOVA) and combined ANOVA were used to quantify reliability coefficients for intraclass and interclass correlations. RESULTS: The overall chance-corrected agreement kappa for all observers was.80 (95% confidence interval [CI] .79 to .81), and the probability of agreement between 2 random observers on a random case was.539. For nurses alone, kappa=.84 (95% CI .83 to .85, P = .598), and for doctors alone, kappa= .83 (95% CI .81 to .85, P = .566). The 1-way, 2-way ANOVA and combined ANOVA showed that the reliability coefficients (84%) for both nurses and physicians were similar to the kappa values. A combined ANOVA showed there was a. 2-point difference with physicians assigning a higher triage level. CONCLUSION: The high rate of interobserver agreement has important implications for case mix comparisons and suggests that this scale is understood and interpreted in a similar fashion by nurses and physicians.

Analysis of Variance↗
PubMed1999

A double-blind, randomized, controlled multicentre study to compare the efficacy of ciprofloxacin with pivampicillin as oral therapy for epididymitis in men over 40 years of age.

OBJECTIVE: To compare the efficacy and safety of ciprofloxacin 500 mg orally twice daily with pivampicillin 700 mg orally twice daily for 10 days in men with acute epididymitis and over 40 years of age. PATIENTS AND METHODS: The study comprised 172 men who entered a prospective, controlled, randomized, double-blind, trial of pivampicillin and ciprofloxacin. The median (range) age of the 158 patients eligible for the efficacy analysis was 58 (41-85) years; 41% had previously had a urinary tract infection and 27% had previously had epididymitis. Only one patient had a urethral catheter and 38% were sexually active. About half of the patients were admitted to hospital. RESULTS: No bacteria could be cultured from samples in 53% of the patients; Escherichia coli could be cultured from 35% and the remaining isolates were the expected urinary pathogens. None of the patients had Gonococci and only one in each group had Chlamydia. Mycoplasma hominis was detected in three patients only and M. genitalium was detected in three, while Ureaplasma was detected in 24 (15%). The treatment failed in 48 patients; in 15 of 76 (20%) receiving ciprofloxacin and in 33 of 82 (40%) receiving pivampicillin. This corresponds to a reduction in the risk of failure of 20.5% (95% confidence limits 6.6-40.2%, P=0. 006). The principal cause of failure was an unsatisfactory clinical response requiring changed antibiotic treatment in 27 patients; adverse events were responsible for failure in 14. The in vitro resistance of cultured bacteria was low in both groups, at approximately 4%. Adverse events, mainly gastro-intestinal, occurred in 17 of 83 (21%) patients starting on ciprofloxacin and in 33 of 89 (37%) receiving pivampicillin (P=0.04). CONCLUSION: For epididymitis in men over the age of 40 years ciprofloxacin 500 mg orally twice daily is more effective than pivampicillin 700 mg orally twice daily. Furthermore, ciprofloxacin has a lower incidence of adverse events.

Administration, Oral↗
PubMed1999

The responsiveness of the ICSmale questionnaire to outcome: evidence from the ICS-'BPH' study.

OBJECTIVE: To evaluate the responsiveness of the ICSmale questionnaire to the outcome of treatments for lower urinary tract symptoms (LUTS). PATIENTS AND METHODS: Consecutive men aged >45 years attending 23 urology centres in 12 countries, with symptoms suggestive of bladder outlet obstruction secondary to benign prostatic hyperplasia (BPH), were recruited to Phase I of the International Continence Society (ICS)-'BPH' study. In Phase II of the ICS-'BPH' study, 355 men in 15 centres in nine countries were followed up, having proceeded to treatment according to clinical practice. All men completed the ICS-'BPH' study questionnaire at baseline and follow-up, including the ICSmale which concerns LUTS and related problems. RESULTS: Patients included in Phase II were similar to those in Phase I according to age and levels of baseline symptoms. Patients received a range of treatments: 32% TURP, 29% drug therapies, 20% watchful waiting, 9% minimally invasive therapies and 10% 'others' (including open prostatectomy). For patients who underwent TURP, most LUTS, including voiding and filling symptoms, were highly statistically significantly better at follow-up than at baseline (P<0.0001). For drug, minimally invasive and 'other' treatments, fewer LUTS were highly statistically significantly better. For those undergoing watchful waiting, no symptoms were significantly different between baseline and follow-up. CONCLUSION: The ICSmale questionnaire, in addition to being psychometrically valid and reliable, is responsive to change in outcome.

Age Factors↗
PubMed1999

An automated technique for the simultaneous determination of cations in nanoliter volumes.

BACKGROUND: The study of ion transport along the renal tubule in vivo or in vitro requires a technique capable of analyzing ion concentrations in sample volumes of only a few nanoliters. This article describes a method for the analysis of cations at physiological concentrations in samples of tubular fluid taken from single renal tubules in vivo. Method. A background electrolyte composed of 2-[N-Morpholino] ethane-sulfonic acid (MES) (50 mmol/liter) and L-histidine (50 mmol/liter; pH congruent with 6.2), with the additives 18-crown-6 (1 mmol/liter) and methanol (30%) was used for the cation separation combined with conductivity detection. RESULTS: Capillary zone electrophoresis was used to separate NH4, K, Na, Ca, Li, Mg, and Ba in six minutes. Simultaneous quantitative analysis was performed for sodium and potassium, providing detection limits of 0.2 pmol for sodium and 30 fmol for potassium. The calibration plots were linear over three orders of magnitude, including the range of interest to clinical analysis. Data on the reproducibility and repeatability of peak areas and of the repeatability of migration times are reported. CONCLUSION: The results for sodium and potassium are in close agreement with those obtained by atomic absorption spectrometry, indicating that this is a suitable technique for the routine measurement of these cations in tubule fluid samples.

Automation↗
PubMed1999

Suppression of acquired immunity against Listeria monocytogenes by amphotericin B-mediated inhibition of CD8 T cell function.

Amphotericin B is frequently used for the treatment of fungal infections of immunocompromised individuals. Whereas immunomodulatory side effects of this agent are known, the influence of amphotericin B was studied in the model of murine Listeria monocytogenes infection. Treatment of L. monocytogenes-immune mice with a nontoxic dose of amphotericin B (0.75 mg/kg) reduced antilisterial protection by 4-5 orders of magnitude, while it had no significant effect on natural immunity against L. monocytogenes in naive mice. Treatment of mice with amphotericin B also abolished the protection mediated by transfer of an L. monocytogenes-specific CD8 T cell line. Furthermore, in vitro analysis showed that amphotericin B impaired target cell lysis and interferon-gamma production by peptide-specific CD8 T cell lines and antigen presentation by L. monocytogenes-infected macrophagelike cells. These data indicate that amphotericin B has a strong suppressive effect on the function of CD8 T cells in vitro and in vivo.

Amphotericin B↗
PubMed1999

Immunochemical evidence that cholesteryl ester transfer protein and bactericidal/permeability-increasing protein share a similar tertiary structure.

Cholesteryl ester transfer protein (CETP) plays an important role in plasma lipoprotein metabolism through its ability to transfer cholesteryl ester, triglyceride, and phospholipid between lipoproteins. CETP is a member of a gene family that also includes bactericidal/permeability-increasing protein (BPI). The crystal structure of BPI shows it to be composed of two domains that share a similar structural fold that includes an apolar ligand-binding pocket. As structurally important residues are conserved between BPI and CETP, it is thought that CETP and BPI may have a similar overall conformation. We have previously proposed a model of CETP structure based on the binding characteristics of anti-CETP monoclonal antibodies (mAbs). We now present a refined epitope map of CETP that has been adapted to a structural model of CETP that uses the atomic coordinates of BPI. Four epitopes composed of CETP residues 215-219, 219-223, 223-227, and 444-450, respectively, are predicted to be situated on the external surface of the central beta-sheet and a fifth epitope (residues 225-258) on an extended linker that connects the two domains of the molecule. Three other epitopes, residues 317-331, 360-366, and 393-410, would form part of the putative carboxy-terminal beta-barrel. The ability of the corresponding mAbs to compete for binding to CETP is consistent with the proximity of the respective epitopes in the model. These results thus provide experimental evidence that is consistent with CETP and BPI having similar surface topologies.

Antibodies, Monoclonal↗
PubMed1999

Two nursing home outbreaks of respiratory infection with Legionella sainthelensi.

OBJECTIVE: To describe outbreaks of infection caused by Legionella sainthelensi occurring in older residents of two nursing homes and to determine risk factors for the development of infection. DESIGN: Descriptive epidemiology and a case-control study. SETTING: Two nursing homes (140 beds and 254 beds in nursing homes A and B, respectively) located in southern Ontario, Canada, experiencing outbreaks of respiratory tract infection in July and August 1994. SUBJECTS: Case-residents of the two nursing homes who met clinical and laboratory criteria for Legionella infection. Control-residents were defined as those who were in the homes during the outbreaks and were asymptomatic. MEASUREMENTS: Active surveillance was conducted in both nursing homes to identify symptomatic residents. Residents with fever or respiratory tract symptoms had nasopharyngeal swabs taken for viral antigen detection and culture, urine for Legionella antigen detection, and acute and convalescent serology for viruses, Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella. Chest X-rays were performed, and an attempt was made to obtain blood and sputum cultures. Water samples from shower heads, faucets, and air conditioning units were collected for Legionella culture and polymerase chain reaction (PCR) assay. A case-control study was done to assess possible risk factors for legionellosis. RESULTS: Twenty-nine cases -- 17 in nursing home A; 12 in nursing home B - were identified. Four (14%) case-residents had documented pneumonia and four case-residents died. Univariate analysis revealed that a history of stroke (odds ratio (OR) 2.3 (95% CI, 1.0-5.3)), eating pureed food (OR 4.6 (95% CI, 1.6-12.7)), and having fluids administered with medication (OR 2.5 (95% CI, 1.0-5.9)) were significant risk factors. Cases were less likely to wear dentures (OR .4 (95% CI, .2-.9)) or to eat solid food (OR .3, (95% CI, .1-.6)). Only eating pureed food remained significant in a multivariable analysis (OR 4.6 (95% CI, 1.6-13.0, P = .01)). CONCLUSION: This report describes outbreaks of legionellosis in two nursing homes, representing the first reported outbreaks of infection caused by Legionella sainthelensi. The association with illness of dietary characteristics indicative of swallowing disorders suggests that aspiration was the most likely mode of infection. The diagnosis of legionellosis should be considered during outbreaks of respiratory infection in nursing homes.

Aged↗
PubMed1999

Electron microscopy studies of cell-wall-anchored cellulose (Avicel)-binding protein (AbpS) from Streptomyces reticuli.

Streptomyces reticuli produces a 35-kDa cellulose (Avicel)-binding protein (AbpS) which interacts strongly with crystalline cellulose but not with soluble types of cellulose. Antibodies that were highly specific for the NH2-terminal part of AbpS were isolated by using truncated AbpS proteins that differed in the length of the NH2 terminus. Using these antibodies for immunolabelling and investigations in which fluorescence, transmission electron, or immunofield scanning electron microscopy was used showed that the NH2 terminus of AbpS protrudes from the murein layer of S. reticuli. Additionally, inspection of ultrathin sections of the cell wall, as well as biochemical experiments performed with isolated murein, revealed that AbpS is tightly and very likely covalently linked to the polyglucane layer. As AbpS has also been found to be associated with protoplasts, we predicted that a COOH-terminal stretch consisting of 17 hydrophobic amino acids anchors the protein to the membrane. Different amounts of AbpS homologues of several Streptomyces strains were synthesized.

Bacterial Proteins↗
PubMed1999

Medullary metastasis causing impairment of respiratory pressure output with intact respiratory rhythm.

We present an unusual case of weaning failure. A 67-yr-old man presented with confusion, hyponatremia, and hypercapnic respiratory failure that necessitated mechanical ventilation. CXR revealed a right hilar mass (non-small-cell carcinoma on biopsy). Level of consciousness improved with treatment of his hyponatremia. However, attempts at weaning were complicated by hypercapnia with no overt distress. Resistance and elastance were only slightly abnormal, excluding mechanics as a cause of respiratory failure. Maximal inspiratory pressure (MIP) and vital capacity (VC) were reduced at -15 cm H2O and 0.97 L, respectively. Limb muscle strength was well preserved, suggesting isolated respiratory muscle weakness. During a weaning trial respiratory rate increased from 7 to 40 breaths/min as PCO2 increased from 56 to 89 mm Hg, confirming an intact respiratory pacemaker and good response to CO2. However, spontaneous Pdi was only 1 to 2 cm H2O (< 20% of Pdimax) despite profound hypercapnia. The fact that the patient did not utilize a greater fraction of his pressure-generating capacity suggested preferential impairment of the automatic respiratory centers. MRI showed a large central metastatic lesion in the rostral medulla with only a thin rim of uninvolved tissue. This case illustrates the utility of relating the magnitude of spontaneous efforts to maximal voluntary efforts as a means of localizing the site of involvement in cases of respiratory muscle weakness. It also demonstrates that a large medullary mass lesion may selectively impair brainstem modulation of respiratory pressure output while sparing other medullary functions, and in particular the pacemaking function of the respiratory centers.

Aged↗
PubMed1999

Secretory peptides TFF1 and TFF3 synthesized in human conjunctival goblet cells.

PURPOSE: The objective of this study was to determine whether human conjunctival epithelium synthesizes TFF-peptides (formerly P-domain peptides, trefoil factors), a family of mucin-associated secretory peptides of the gastrointestinal tract. METHODS: Expression of TFF-peptides in human conjunctiva was monitored by reverse transcription-polymerase chain reaction analysis. Antisera specific for TFF-peptides were used for immunohistochemistry to determine the presence and distribution of TFF-peptides in human conjunctiva. RESULTS: mRNA expression of TFF1 and TFF3, but not TFF2, was detected in human conjunctiva. TFF1 and TFF3 but not TFF2 are stored in conjunctival goblet cells only as revealed by immunofluorescence. CONCLUSIONS: Goblet cells of the human conjunctiva synthesize TFF1 and TFF3. These peptides, together with the secretory ocular mucin MUC5AC, may contribute to the rheological properties of the tear film. They also may influence healing of corneal wounds due to their motogenic properties.

Aged↗
PubMed1998

Quantification of the antipsychotics flupentixol and haloperidol in human serum by high-performance liquid chromatography with ultraviolet detection.

A high-performance liquid chromatography (HPLC) method was developed for quantification of both isomers of the thioxanthene neuroleptic flupentixol and of the butyrophenone derivative haloperidol in human serum. After extraction with diethyl ether-n-heptane (50:50, v/v), an isocratic normal-phase HPLC system with a Hypersil cyanopropyl silica column (250x4.6 mm, 5 microm particle size) was used with ultraviolet detection at 254 nm and elution with a mixture of 920 ml acetonitrile, 110 ml methanol, 30 ml 0.1 M ammonium acetate, and 50 microl triethylamine. The limit of quantitation of 0.5 ng/ml and 0.3 ng/ml for flupentixol and haloperidol, respectively, was sufficient to quantify both compounds in serum after administration of clinically adjusted doses. The suitability of the described method for therapeutic drug monitoring and clinical pharmacokinetic studies was assessed by analysis of more than 100 trough level serum samples.

Antipsychotic Agents↗
PubMed1998

"Incomplete resection" in non-small cell lung cancer: need for a new definition. Canadian Lung Oncology Group.

BACKGROUND: This study was designed to determine the prognostic value of positive surgical resection margin or highest nodal station sampled at thoracotomy in patients with non-small cell lung cancer. METHODS: Two reviewers independently examined the surgical records and pathologic reports from a randomized trial comparing computed tomography versus mediastinoscopy for staging of lung cancer. They recorded pathologic findings at the surgical resection margin, the highest mediastinal nodal station sampled at thoracotomy, histologic type, tumor size, N status, and evidence of vascular or lymphatic invasion. These variables formed the independent variables in logistic regression models to predict recurrence. RESULTS: Except for 1 patient, follow-up at 3 years for 399 included patients was complete. Significant predictors of recurrence were tumor size (odds ratio [OR], 1.2 (per centimeter); 99% CI [confidence interval], 1.1 to 1.4), and N status (compared with N0, N1: OR, 1.6; CI, 0.8 to 3.1; N2: OR, 3.2; CI, 1.4 to 7.5). Other variables, including positive surgical resection margin, did not predict early recurrence or death. CONCLUSIONS: In patients with non-small cell lung cancer, surgical resection margin or highest nodal station sampled at thoracotomy that are involved by carcinoma do not predict recurrence. The current definition of incomplete resection has limited prognostic significance.

Aged↗