Concurrent outbreaks with co-infection of norovirus and Clostridium difficile in a long-term-care facility.

We describe an outbreak of simultaneous Clostridium difficile and norovirus infections in a long-term-care facility. Thirty patients experienced acute gastroenteritis, and four had co-infection with identical C. difficile 027 and genotype II.4 New Orleans norovirus strains. Co-occurring infection requires improved understanding of risk factors, clinical impact, and testing strategies.

Identification of perineural cysts during ultrasound-guided caudal anaesthesia.

An 8-year-old boy was scheduled for urethral fistula correction under general anaesthesia with an ultrasound-guided caudal block. During scanning of the caudal area, we noticed two cystic structures in the caudal space in the region of the intended needle endpoint so we decided against performing the caudal block. Surgery was conducted uneventfully and a penile block was administered as an alternative for analgesia postoperatively. Radiological evaluation of the child 3 weeks later revealed the presence of perineural cysts in the sacral region. Routine use of ultrasound for caudal anaesthesia procedures may reveal unexpected anomalies in the sacral area, which could have implications for optimal patient management.

Primary HIV-1 infection--a "window of opportunity" for healthcare providers.

The diagnosis of primary HIV-1 infection (PHI) is often missed and requires a high index of suspicion and a thorough knowledge of laboratory methods. We report the case of a young promiscuous male who presented with fever, rash and neurological symptoms 8 weeks after unprotected sexual exposure. Clinical and laboratory investigations showed the presence of leucopenia and thrombocytopenia with elevated transaminases, and a normal cerebrospinal fluid analysis, while CNS imaging revealed a vasculitis-like involvement of the corpus callosum. Symptoms resolved spontaneously over 3 weeks. Fourth generation ELISA with p24 antigen assay was positive with high HIV-1 RNA load while Western-Blot was negative, thus confirming the diagnosis of PHI. The patient was subsequently started on antiretroviral therapy (ART) and showed undetectable viral load after 8 weeks of therapy. We present the differential diagnoses which need to be entertained as well as the pros and cons of very early ART intervention.

Nevirapine-induced fulminant hepatitis.

Nevirapine induced hepatotoxicity is known but fatality is rare. We report a case of a young individual who developed nevirapine (NVP) induced fatal hepatitis without apparent risk factors or preceding rash. Exacerbation of underlying silent chronic liver dysfunction possibly contributed to the fatal outcome. This case stresses the need for careful evaluation, regular monitoring and prompt omission of drug on suspicion of hepatotoxicity.

Strength development in concrete with wood ash blended cement and use of soft computing models to predict strength parameters.

In this study, Wood Ash (WA) prepared from the uncontrolled burning of the saw dust is evaluated for its suitability as partial cement replacement in conventional concrete. The saw dust has been acquired from a wood polishing unit. The physical, chemical and mineralogical characteristics of WA is presented and analyzed. The strength parameters (compressive strength, split tensile strength and flexural strength) of concrete with blended WA cement are evaluated and studied. Two different water-to-binder ratio (0.4 and 0.45) and five different replacement percentages of WA (5%, 10%, 15%, 18% and 20%) including control specimens for both water-to-cement ratio is considered. Results of compressive strength, split tensile strength and flexural strength showed that the strength properties of concrete mixture decreased marginally with increase in wood ash contents, but strength increased with later age. The XRD test results and chemical analysis of WA showed that it contains amorphous silica and thus can be used as cement replacing material. Through the analysis of results obtained in this study, it was concluded that WA could be blended with cement without adversely affecting the strength properties of concrete. Also using a new statistical theory of the Support Vector Machine (SVM), strength parameters were predicted by developing a suitable model and as a result, the application of soft computing in structural engineering has been successfully presented in this research paper.

Codiffusion of propylene glycol and dimethyl isosorbide in hairless mouse skin.

The in vitro percutaneous fluxes of propylene glycol (PG), cis-oleic acid (OA) and dimethyl isosorbide (DI) were determined and their effect on nifedipine (N) flux and lag time evaluated. PG, OA and DI flux through hairless mouse (HM) skin was measured in vitro by beta-scintigraphy and N permeation was measured by HPLC under finite and infinite dose conditions. Evaluation of each of the solvents separately showed that pure DI possessed the inherent ability to traverse the skin (12% in 24 h). For the tested formulation after 24 h, 57% of the PG and 40% of the DI had permeated across the skin with nearly linear permeation between 4 and 18 h and the relative order of permeation was PG > DI > N. DI permeation was further aided in the presence of PG and OA. N flux was dependent on concomitant solvent permeation. Over a 24-h test period a dose dependent response was observed for N, with 4.9-15.6 mg of N delivered from the lowest and highest doses, respectively, and the highest dose yielding zero-order flux of 146 (g/h per cm2).

Neisseria gonorrhoeae identification in carbohydrate medium containing guinea pig serum.

Clinical isolates of Neisseria gonorrhoeae from Manitoba were tested for their carbohydrate degradation activity in Cystine Trypticase Agar (C.T.A) medium, Mueller-Hinton Agar and guinea pig serum agar. Each isolate was tested using 2 carbohydrates (e.g. glucose and maltose) in the above three media. Out of 661 isolates tested, only 80% were positively identified in C.T.A. medium. Mueller-Hinton agar allowed 88% identification while guinea pig serum agar yielded 100% identification. In a second series of experiments, 102 cultures of N. gonorrhoeae were used to compare Flynn & Waitkins medium with guinea pig serum agar. Only 91 of these were identified with Flynn and Waitkins medium while guinea pig serum agar identified all the 102 isolates. Guinea pig serum provides adequate growth of fastidious N. gonorrhoeae essential for detecting specific enzymes. Since guinea pig serum does not contain maltase activity, it does not interfere with the biochemical activities tested. Guinea pig serum agar is easy to prepare, does not require a heavy inoculum and gives definite color change in the medium.

Adult duodenal web.

An 18-year-old male presented with persistent vomiting and epigastric fullness of 8 months' duration. Barium examination revealed an abrupt cutoff at the third part of the duodenum. Duodenotomy revealed a web at the third part of the duodenum. Following web excision, the patient experienced marked symptomatic relief and remains well 6 months after surgery.

Radioimmunodiffusion technique for determining diphtheria antitoxin.

A radioimmunodiffusion technique for detecting low levels of diphtheria antitoxin was developed. Diphtheria toxoid was labelled with 125I to facilitate detection of lines of precipitation by the use of X-ray film, the lower limit of detection being 0.001 unit per millilitre of diphtheria antitoxin.

Detection of Clostridium difficile toxin in various tissue culture monolayers.

Thirty stool filtrates known to contain Clostridium difficile toxin based on previous testing on McCoy cells were tested for toxicity on primary African green monkey kidney (AGMK), McCoy, MRC-5, primary rhesus monkey kidney (RMK), and Vero cells. All 30 filtrates showed cytotoxic effect at greater than or equal to 1:100 dilution on McCoy and Vero cells. A total of 22 filtrates were positive on MRC-5 monolayers, while only 16 and 10 filtrates showed positive cytotoxic effect on AGMK and RMK cells, respectively. Another 630 stool specimens were tested on McCoy and Vero cells only. Of these stool filtrates, 70 were positive and 560 were negative with both cell lines, which thus gave 100% agreement. Vero cells can be used interchangeably with McCoy cells for the detection of C. difficile toxin in stool filtrates.

Excretion of mutagens following chemotherapy.

The mutagenic activity of urine was evaluated in children receiving single and multiple agent chemotherapy to determine the duration of carcinogenic risk to health care personnel and family contacts. Urine samples from 21 children were evaluated before and daily for 5 days after chemotherapy administration. Mutagenic activity, a sensitive though not specific indicator of carcinogenic risk, was assayed using mutant strains of Salmonella typhimurium (the "Ames test"). Validity of the assay was confirmed by demonstrating mutagenic activity in urine samples from 17 adult cigarette smokers but not from 21 adult nonsmokers (24/24 versus 0/37, p less than 0.001). None of the 21 children tested demonstrated mutagenic activity before chemotherapy administration. Following single agent dactinomycin, cyclophosphamide, daunorubicin, doxorubicin, methotrexate, or vincristine, mutagenic activity was demonstrated for 2 days (5/5 at 1 and 2 days and 0/5 at 3 days). Following multiple agent chemotherapy using two or three of the latter drugs on a single day, mutagenic activity was demonstrated for 4 or 5 days (16/16 at 1, 2, 3, and 4 days, and 4/16 at 5 days). Based on these observations with urine, and presumably other body fluids, precautions are recommended for 2 days following single agent and at least 5 days following multiple agent chemotherapy.

Identification of Chlamydia trachomatis by direct immunofluorescence applied in specimens originating in remote areas.

The efficacy of the MicroTrak (Syva Co., Palo Alto, Calif.) direct immunofluorescence test for the detection of Chlamydia trachomatis was compared with cell culturing of fresh specimens obtained from patients attending a clinic on sexually transmitted disease and of frozen specimens delayed in transit from urban or remote physicians' offices and clinics. Direct immunofluorescence testing detected C. trachomatis more frequently than culturing of the same specimens when transit caused a delay in culturing.

Detection of verotoxin in stool specimens.

A total of 132 fecal specimens containing verotoxin (VT) were subjected to counter-current immunoelectrophoresis (CIE). Of these, 113 (85.6%) were found to be positive by CIE. Another 71 stool specimens containing E. coli serogroup O157 but with flagellar antigens other than H7 were tested for verotoxin by CIE. These stool specimens were negative for VT on Vero cell monolayers. Of these 71 stool specimens, 6 (8.5%) gave positive tests for verotoxin by CIE. Forty stool specimen filtrates which were negative for VT (negative controls) were also subjected to CIE. One of these stool specimen filtrates gave a line of precipitation by CIE. The specificity of the CIE test was 93.7%, and the sensitivity was 85.6%. False-positive results may have been due to an antibody component against the somatic antigen (O157) in the antitoxin used; this is a limitation of the CIE test. In a related evaluation, 302 stool specimen filtrates containing VT were retested with Vero cell suspension cultures in microdilution plates. Of these, 281 stool specimen filtrates showed cytotoxic effects within 24 h, while the remaining 21 filtrates showed the effects within 48 h. The use of Vero cell suspension culture is as reliable as the use of Vero cell monolayers and provides detection of verotoxin 24 to 48 h sooner.