Measurement of Clostridium perfringens beta-toxin production by surface plasmon resonance immunoassay

A rapid and sensitive assay using surface plasmon resonance (SPR) immunoassay has been developed for the detection of Clostridium perfringens beta-toxin. The SPR immunoassay was conducted off-line by passing fermentation broth by a sensor chip coated with a monoclonal antibody specific for C. perfringens beta-toxin. Quantitation of toxin using SPR immunoassay was achieved by mass transport analysis; results were obtained within 20 min. The SPR immunoassay was compared with an ELISA and the traditional bioassay for C. perfringens beta-toxin. The SPR immunoassay and ELISA detected at least twofold differences in toxin levels at 95% confidence over a broad range of toxin concentrations. The traditional bioassay did not produce the resolution observed with the immunoassays. The SPR immunoassay allows for real-time monitoring of beta-toxin accumulation during production and permits the bioengineer to harvest C. perfringens fermentations when toxin is most concentrated. The SPR methodology may be applied to other fermentations to enhance and optimize toxin yields.

Contamination of embryo transfer catheter and treatment outcome in in vitro fertilization

PURPOSE

The effect of embryo transfer (ET) catheter contamination with mucus and/or blood on treatment outcome in an in vitro fertilization (IVF) program was evaluated.

METHODS

One thousand four ET procedures in 877 patients having conventional IVF in the long (1189 cycle) and short (15 cycles) protocol were analyzed to determine the impact of catheter contamination on the incidence of retained embryos and the clinical pregnancy rate.

RESULTS

Catheter contamination with mucus and/or blood is a feature of difficult ET. Embryos were significantly more likely to be retained when the transfer catheter was contaminated with mucus (17.8 versus 3.3%) or blood (12 versus 3.3%). When the catheter was contaminated and an embryo(s) was retained and immediately retransferred, the pregnancy rate was not compromised. The pregnancy rate was significantly reduced when the ET catheter was contaminated with blood (15.5 versus 27.1%; P = 0.002), but no embryo was retained in the catheter set.

CONCLUSIONS

Catheter contamination compromises the treatment outcome in IVF only when there is no associated retained embryo(s). As increased vigilance in searching for extruded embryos may not be practical, we suggest that cervical mucus should be routinely aspirated and ET performed as atraumatically as possible.

Restoration of the severely worn dentition using a systematized approach for a predictable prognosis

Dental literature supports the concept that vertical dimension of occlusion is normally not lost in severely worn dentition, and the bite should generally not be opened to facilitate dental reconstruction. However, restoration of a periodontally sound but severely worn dentition, at existing vertical dimension, frequently presents unique challenges in patient management, diagnosis, treatment planning, and restorative methodology. This report reviews and demonstrates an integrated and planned approach to this complex treatment situation that can lead to a favorable and predictable prognosis. The approach also allows a practitioner free use of various techniques if certain goals of occlusion are followed.

The recognition of haemoglobin by antibodies raised for the immunoassay of beta-amyloid

Canine and porcine cerebrospinal fluid (CSF) were fractionated by size exclusion chromatography and analysed by a luminescence enzyme linked immunosorbent assay (ELISA) configured to detect beta-amyloid. A peak of activity was observed in the CSF consistent with the molecular weight of beta-amyloid. When CSF contaminated with blood was analysed an additional peak of immunoreactivity at a higher molecular weight was observed. The peak of activity was found to be derived from cross-reactivity of the immunoglobulins employed in the ELISA with haemoglobin. These findings are discussed with reference to primary and structural sequence homology between beta-amyloid and haemoglobin from a number of species, the known properties of beta-amyloid and recent clinical reports.

Among young adults, college students and graduates practiced more healthful habits and made more healthful food choices than did nonstudents

OBJECTIVES

Health-related characteristics and habits and food choices of young adults were compared for three groups: college students, college graduates, and nonstudents.

DESIGN

Subjects completed a mailed survey that included questions about demographics, attitudes, and behaviors and a food frequency questionnaire. Main outcome measures were health-related characteristics and habits and food choices.

SUBJECTS

Female (n = 758) and male (n = 580) 18- to 24-year-olds in nine states who were selected randomly by zip code in each state. The response rate averaged 43% for all states.

STATISTICAL ANALYSES PERFORMED

Analysis of variance of chi 2 tests were applied to health-related personal characteristic variables and the Kruskal-Wallis analysis of variance was applied to food consumption variables for women and men separately.

RESULTS

According to self-reported heights and weights, female nonstudents were more often overweight than female students or graduates. Nonstudents of both genders reported smoking more often than students or graduates. College students and graduates ate more grain foods high in dietary fiber, more fruits and dark-green vegetables, and more lower-fat milk and meats than nonstudents.

CONCLUSIONS/APPLICATIONS

Nonstudents were at greater health risk for some chronic illnesses, because of poorer health habits and food choices, than were college students and graduates. The behavior of nonstudents implies weaker response to messages promoting weight control, smoking cessation, and observance of the Dietary Guidelines for Americans than behavior exhibited by students or college graduates. Health promotion efforts could be enhanced by identifying demographic, educational, situational, and formative influences on positive health and dietary behaviors of young adults.

Multiple attempts at embryo transfer: does this affect in-vitro fertilization treatment outcome?

In this study, we retrospectively analysed data from 877 patients who had 1204 embryo transfer procedures following in-vitro fertilization (IVF) at Midland Fertility Services, UK, between January 1991 and December 1995 to investigate the factors contributing to failure of embryo transfer at first attempt and the impact of immediate retransfer of retained embryos on the treatment outcome. Embryos were significantly more likely to be retained when the embryo transfer catheter was contaminated with mucus (3.3 versus 17.8%, P = 0.000001) or blood (3.3 versus 12%, P = 0.00001) and when the transfer procedure was difficult compared with when it was easy (20.3 versus 0.8%, P = 0.00001). There was no significant difference in the clinical pregnancy rate between those who had all their embryos transferred at the first attempt (24.7%) and those who required more than one attempt (23.2%). The types of embryo transfer catheter used in the unit did not show any difference in terms of embryo retention. Although we recommend aspiration of cervical mucus in order to reduce the rate of retained embryos, there is no evidence from our study to suggest that pregnancy rate is compromised when embryos are retained, provided they are discovered and immediately retransferred into the uterine cavity. Immediate retransfer is more convenient to the patients and reduces the laboratory workload without compromising the treatment outcome.

An office system for organizing preventive services: a report by the American Cancer Society Advisory Group on Preventive Health Care Reminder Systems

Despite increasing recognition of the importance of preventive services, such services are not provided in primary care practice as often as recommended. One of the most important reasons is the lack of a systematic, organized approach within practices. The American Cancer Society Ad Hoc Advisory Group on Preventive Health Care Reminder Systems reviewed evidence-based reports and expert opinion to summarize current knowledge about office systems for clinical preventive services. This article describes the process of developing an office system for preventive care, beginning with writing a practice policy, auditing charts for baseline performance, developing and implementing a plan for efficient delivery of preventive care, involving office staff, and monitoring progress. Strategies for dissemination of this approach to a wide range of primary care practices may involve professional medical organizations and managed care companies.

Response of growing swine to dietary exposure to pure fumonisin B1 during an eight-week period: growth and clinical parameters

Consumption of corn or corn-based products contaminated with Fusarium moniliforme/fumonisins has been associated with a variety of animal and human diseases and is a major food/feed safety issue. This study focused on the clinical toxicity and performance parameters in growing swing exposed to low to moderate levels of pure fumonisin B1 (FB.) for 8 weeks. Male (castrated) and female pigs were fed diets containing 0,0.1,1.0, and 10 mg FB1/kg diet (ppm). Weight gains and feed consumption were measured weekly. Blood samples were collected throughout the study, and various clinical and hematological parameters were measured. Because fumonisins are potent inhibitors of sphingolipid biosynthesis, sphinganine and sphingosine concentrations were determined in the liver, lung, and kidney. Organ weights and carcass quality were measured at the end of the trial. In general, male pigs were more adversely affected by FB1 in the diet than females. The average daily gain for males decreased by 8% for pigs fed 1.0 ppm and by 11% at 10.0 ppm, when compared to the control (0 ppm). Males fed 0.1 ppm showed an erratic growth pattern during the first 5 weeks of the experiment. Feed consumption for the same animals was somewhat higher than that of the controls during each of the first 4 weeks but thereafter was 6-7% lower each week as compared to controls. Female pigs fed FB1-diets showed a general enhancement of feed consumption until week 4. Among clinical chemistry parameters, cholesterol increased in males for the 1.0 and 10.0 ppm diets as compared to controls after 2 weeks, while the levels in both sexes were elevated for the 1.0 ppm diet only by the end of the experiment. Serum liver enzyme concentrations were altered during week 2 only. Changes were observed in the weight of the pancreas and adrenals for male pigs fed FB1 diets as compared to controls. The free sphinganine to free sphingosine ratio (biomarker of exposure in FB1-consuming animals) increased in all three organs for the 10 ppm diet, regardless of sex. The study indicated that FB1 can cause different effects at each dose level, at concentrations as low as 0.1 ppm (showing erratic growth) followed by a reduced growth and biochemical abnormalities in blood (1.0 ppm) and sphingolipid alterations in tissues (10.0 ppm). Some of these effects occurred below the exposure level that caused alteration in sphingolipid metabolism.

Enhanced anticaries efficacy of a 0.243% sodium fluoride/10% xylitol/silica dentifrice: 3-year clinical results

PURPOSE

To evaluate the efficacy of a sodium fluoride (NaF)/silica/xylitol dentifrice compared with that of a positive control NaF/silica dentifrice on caries increments in school children over a 3-year period in an area without an optimal level of fluoride in the drinking water (mean level <0.1 ppm).

MATERIALS AND METHODS

A 3-year, double-blind clinical caries study was conducted in 2,630 children initially aged 8-10 years at 17 schools in the San Jose, Costa Rica metropolitan area. Clinical dental examinations were performed at participating schools utilizing portable dental equipment. Caries evaluations employed conventional tactile/visual methodology consisting of artificial light, dental mirrors and single-edge #23 explorers. Children accepted into the study were stratified by age and sex into two balanced groups within each school, and randomly assigned to use either a positive control dentifrice containing 0.243% NaF/silica or a test dentifrice containing 0.234% NaF/silica/10% xylitol. Children were instructed to brush with the assigned dentifrice twice daily. Caries evaluations were conducted at baseline, 2 years, and 3 years.

RESULTS

After 3 years, subjects using the 0.234% NaF/silica/10% xylitol dentifrice had statistically significantly reduced decayed/filled surfaces (DFS; -12.3% reduction; P < or = 0.001) and decayed/filled buccal and lingual surfaces (DFS-BL; -10.5% reduction; P < or = 0/01).

Comparison of Milli-Q PF Plus water to DEPC-treated water in the preparation and analysis of RNA

The Milli-Q PF Plus water-polishing system is equipped with high-purity ion and organic removal media and a capillary fiber ultrafiltration device. The system produces ultrapure water practically free of ribonuclease contamination. The necessity for diethyl pyrocarbonate (DEPC)-treated solutions in RNA molecular biological procedures was tested by preparing RNA from a variety of tissues and tissue-cultured cells using either DEPC-treated, autoclaved solutions or pure Milli-Q PF water dispensed directly from the system. Tissue sources included rabbit brain, heart, lung, liver kidney and bladder as well as cultured human corpus cavernosum smooth muscle cells. RNA was prepared by guanidinium isothiocyanate solubilization, phenol/chloroform extraction and isopropanol precipitation followed by Northern blot analysis. Hybridization with fibronectin (ca. 7.6 kb) and glyceraldehyde-3-phosphate dehydrogenase (1.2 kb) revealed that water from a Milli-Q PF water system performed as well as DEPC-treated, autoclaved solutions. RNA stability at 37 degrees C was examined for various times using rabbit lung RNA in either DEPC-treated water for Milli-Q PF water. Intact RNA was detected after 6 hours in total RNA and by Northern blots hybridized with fibronectin. There was no significant difference in RNA degradation between DEPC-treated water and Milli-Q PF water. We conclude that Milli-Q PF water is an acceptable substitute for DEPC-treated water for the preparation of RNA and Northern blot analysis.

Sexual dimorphism in the metabolic response to the calcium channel antagonists, diltiazem and clentiazem, by hyperlipidemic JCR:LA-cp rats

The JCR:LA-cp rat is obese, insulin resistant, and hypertriglyceridemic. The obese male rats spontaneously develop atherosclerosis and ischemic myocardial lesions that are prevented by treatment with the calcium channel antagonist, nifedipine. Male and female JCR:LA-cp rats were treated with the calcium channel antagonist, diltiazem, and a closely related compound, clentiazem (at 30 mg/kg). Clentiazem, but not diltiazem, caused a significant increase in body weight of both sexes in the presence of decreased food consumption. Serum triacylglycerols were decreased by half by both drugs in male rats only, reflecting decreased very-low-density lipoprotein (VLDL) secretion. Females did not respond with lower concentrations of triacylglycerol (although VLDL secretion rate was decreased) and showed increased concentrations of cholesterol in the high-density lipoprotein (HDL) fraction. Diltiazem-treated male rats showed decreased VLDL particle size, together with a shift to shorter-chain fatty acids in the triacylglycerols. This effect was not seen with clentiazem treatment. There was no effect on insulin and glucose metabolism in these insulin-resistant animals. Calcium channel antagonists have complex metabolic effects in the hypertriglyceridemic rats, with highly beneficial hypolipidemic effects in the males that are not seen in the females. The sexual dimorphism of these responses is sex linked, but appears not to be due to the steroid sex hormones. These results suggest caution in the chronic treatment of human females with these agents and the importance of detailed human studies in females and individuals with the insulin-resistant/hypertriglyceridemic/obese syndrome.

Bactericidal effects of ozone at nonspermicidal concentrations

A study was conducted to assess the use of ozone (O3) to control pathogens or contaminants of concern to animal breeders and regulatory officials. In separate experiments, samples of fresh bovine semen and Pseudomonas aeruginosa, Escherichia coli, or Campylobacter fetus subsp. venerealis were diluted with antibiotic-free milk (10(6) sperm and 10(6) organisms/mL of diluted semen), exposed in the previous day to a constantly monitored level of 5, 10, 15, or 20 micrograms/mL of O3 for 3-5 min. After 10 min at 30 degrees C, sperm motility was assessed and the samples cooled to 5 degrees C. Two and 18 h after the beginning of cooling, aliquots of each semen sample were evaluated for motility and cultured for organisms. Reductions were observed in P. aeruginosa and E. coli colony counts of 2 logs, and in C. fetus of 5 logs, after exposure for 2 h to O3 at a concentration of 5 micrograms/mL that had a moderate effect on sperm motility (reduction of 20%). Fewer than 100 colonies, i.e., a 4 logs reduction of all bacteria, were counted after dilution with ozonized-treated milk at 20 micrograms/mL of O3. However, this concentration of O3 reduced sperm motility by 50% 10 min after dilution. The results of these experiments indicate that a concentration and exposure time to O3 can be selected to reduce P. aeruginosa, E. coli, and C. fetus in contaminated bull semen diluted with milk while having only minimal effects on sperm motility.

Solid organ procurement from burn patients

With the increasing success or organ transplantation and the consequent increasing scarcity of suitable organs, many traditional contraindications to organ procurement are being reconsidered. One such traditional contraindication to organ procurement is burn injury. We report a case of successful multiorgan procurement from a child with an extensive burn and propose guidelines for solid organ harvest from burn patients.

Normal sweat chloride values do not exclude the diagnosis of cystic fibrosis

Since its introduction in 1959, the sweat test has remained the "gold standard" diagnostic test for cystic fibrosis (CF). It is apparent that CF encompasses a wide spectrum of disease, from meconium ileus and severe respiratory compromise in infants to the presentation of mild pulmonary symptoms and no evidence of gastrointestinal disease in adults. In patients with lung disease that might otherwise be consistent with CF, normal sweat chloride (Cl-) values have tended to exclude the diagnosis. In this report we describe two patients from two families with the compound heterozygotic CF mutations delta F508/3849 + 10 kb C-->T. These patients had mild manifestations of disease, including clinical pancreatic sufficiency (normal growth without pancreatic enzyme supplementation) and absence of azoospermia. Sweat Cl- values were in the normal range. However, both patients developed bronchiectasis, progressive obstructive lung disease, and colonization with Pseudomonas. The diagnosis of CF was made using nasal transepithelial voltage measurements and genotyping. These cases emphasize the need to maintain a high index of suspicion of CF in atypical cases, and to pursue alternative diagnostic tests to confirm a diagnosis of CF suspected on clinical grounds, despite normal sweat test results.

Hepatic concentrations of zinc, copper and manganese in infants with extrahepatic biliary atresia

The objective of this study was to determine the concentration of Zinc (Zn), Copper (Cu) and Manganese (Mn) in hepatic tissue from extrahepatic biliary atresia (EHBA). Liver biopsy samples were obtained at time of portoenterostomy from 49 infants ages 1.1 to 20.7 months (median 2.1) with EHBA. Samples were dry ashed and analyzed by flame (Zn) or flameless (Cu and Mn) atomic absorption spectrophotometry. Hepatic Cu concentrations are physiologically elevated at birth and decline rapidly during the first 2 month of life, therefore only samples from 29 infants, ages greater than 8 weeks were considered for Cu. Concentrations (mg/kg dry weight, mean and range) were: Zn 142 (70-507), Cu 204 (19-570), Mn 9.1 (2.8-21.8) vs. literature controls in the same age range: Zn 262 (82-543), Cu 92, Mn 4.3 (3.3-11.5). No correlations were found between serum alkaline phosphatase, AST or total bilirubin and hepatic trace element concentrations, between trace element concentrations and age, or between Cu and Mn. Decreased bile flow with intrahepatic cholestasis may result in hepatic accumulation of Mn as well as Cu. The low hepatic Zn concentrations indicate the need for further study of Zn metabolism in this population.

Human immunodeficiency virus 1-associated necrotizing cholangitis caused by infection with Septata intestinalis

A 30-year-old man with acquired immunodeficiency syndrome developed human immunodeficiency virus 1-related cholangiopathy with atypical radiographic features showing extensive hepatobiliary involvement. Extended clinical evaluation, including endoscopic retrograde cholangiopancreatography, and the results of both ultrasonic- and computed tomographic-guided liver biopsies failed to provide a diagnosis. A laparoscopic needle biopsy of a single 3-cm, firm, tan lesion on the anterior surface of the liver showed severe necrotizing cholangitis. Special stains showed numerous microsporidial spores within the regions of granulomatous inflammation and prominent necrosis. Electron micrographic findings were characteristic of Septata intestinalis, a newly recognized microsporidial species that disseminates from the intestinal tract and is associated with invasive pathology.