A fluorescence-based homogeneous assay for measuring activity of UDP-3-O-(R-3-hydroxymyristoyl)-N-acetylglucosamine deacetylase

UDP-3-O-(R-3-hydroxymyristoyl)-N-acetylglucosamine deacetylase (LpxC) is one of the key enzymes of bacterial lipid A biosynthesis, catalyzing the removal of the N-acetyl group of UDP-3-O-(R-3-hydroxymyristoyl)-N-acetylglucosamine. The lpxC gene is essential in Gram-negative bacteria but absent from mammalian genomes, making it an attractive target for antibacterial drug discovery. Current assay methods for LpxC are not suitable for high throughput screening, since they require multiple product separation steps and the use of radioactively labeled material that is difficult to prepare. A homogeneous fluorescence-based assay was developed that uses UDP-3-O-(N-hexyl-propionamide)-N-acetylglucosamine as a surrogate substrate. This surrogate can be prepared from commercially available UDP-GlcNAc by enzymatic conversion to UDP-MurNAc, which is then chemically coupled to n-hexylamine. Following the LpxC reaction, the free amine of the deacetylation product can be derivatized by fluorescamine, thus generating a fluorescent signal. This surrogate substrate has a K(m) of 367 microM and k(cat) of 0.36 s(-1), compared to 2 microM and 1.5 s(-1) for the natural substrate. Since no separation is needed, the assay is easily adaptable to high throughput screening. IC(50)s of LpxC inhibitors determined using this assay method is similar to those measured by traditional method with the natural substrate.

New cases of Mokola virus infection in South Africa: a genotypic comparison of Southern African virus isolates

Mokola virus, one of the six genotypes within the Lyssavirus genus of the Rhabdoviridae family, is believed to be exclusive to the African continent, where infections in various mammal species have been reported. After an isolation of Mokola virus at Umhlanga on the east coast of South Africa in 1970, the virus was not reported in South Africa until its reappearance in 1995. Since then a total of six new isolates of the virus were made, three from the East London region in 1995 and 1996, two near Pinetown in 1997 and a further isolate in a residential suburb of the city of Pietermaritzburg, in 1998. These isolation sites are respectively about 500 km (East London region) and 23 to 60 km from the site of the 1970 isolation Phylogenetically the three isolates from the East London area were similar and could be distinguished from the four KwaZulu-Natal isolates, which formed a defined group of their own. The viruses comprising these two clusters were also found to be distant from another southern African isolate, made in 1982 in Zimbabwe, Mokola virus isolates thus conforms to a pattern of virus evolution strongly influenced by geographical determinants. In comparison to Rabies virus, of which at least two different biotypes are known and a vast array of different wildlife species contribute to its complex epidemiology on the sub-continent, Mokola viruses have only been isolated form one species, i.e. domestic cats, in South Africa. Nevertheless, the heterogeneity among the Mokola virus isolates is far greater than the degree of variation among the Rabies virus populations of the region.

Homeopathic treatment of acute otitis media in children: a preliminary randomized placebo-controlled trial

BACKGROUND

The use of antibiotics in the initial treatment of acute otitis media is currently being questioned. Homeopathy has been used historically to treat this illness, but there have been no methodologically rigorous trials to determine whether there is a positive treatment effect.

METHODS

A randomized double blind placebo control pilot study was conducted in a private pediatric practice in Seattle, WA. Seventy-five children ages 18 months to 6 years with middle ear effusion and ear pain and/or fever for no more than 36 h were entered into the study. Children received either an individualized homeopathic medicine or a placebo administered orally three times daily for 5 days, or until symptoms subsided, whichever occurred first. Outcome measures included the number of treatment failures after 5 days, 2 weeks and 6 weeks. Diary symptom scores during the first 3 days and middle ear effusion at 2 and 6 weeks after treatment were also evaluated.

RESULTS

There were fewer treatment failures in the group receiving homeopathy after 5 days, 2 weeks and 6 weeks, with differences of 11.4, 18.4 and 19.9%, respectively, but these differences were not statistically significant. Diary scores showed a significant decrease in symptoms at 24 and 64 h after treatment in favor of homeopathy (P < 0.05). Sample size calculations indicate that 243 children in each of 2 groups would be needed for significant results, based on 5-day failure rates.

CONCLUSIONS

These results suggest that a positive treatment effect of homeopathy when compared with placebo in acute otitis media cannot be excluded and that a larger study is justified.

Interresponse times in serial recall: effects of intraserial repetition

The authors examined the effects of intraserial repetition on multitrial serial learning of random consonant lists, analyzing both learning rates and perfect trial interresponse times (IRTs). Lists varied along 3 dimensions: list length, presence or absence of a repeated element, and lag between repeated elements. After achieving a forward-recall criterion on a given list, participants (N = 20) attempted backward recall. At small lags, IRTs between the repeated elements were very short (compared with IRTs from identical positions in nonrepetition lists). At larger lags, the IRT to recall the second repeated item was substantially longer than in control lists. These results reveal a latency analogue of the Ranschburg pattern seen in accuracy data. A Ranschburg pattern was also found in participants' learning rates. These results both generalize the Ranschburg phenomenon and present further challenges to theories of serial order memory.

Streptococcus suis meningitis, a poacher's risk

Streptococcus suis infection is a zoonosis that has been mainly reported in pig-rearing and pork-consuming countries. The most common disease manifestation is meningitis, often associated with cochleovestibular signs. The causative agent is Streptococcus suis serotype 2, found as a commensal in the tonsils of its natural host, the pig. Persons at risk are mostly those with an occupational exposure to domestic pigs or their meat products. A case of meningitis caused by Streptococcus suis in a poacher who had killed and butchered a wild boar is reported. It appears that wild boar hunters are at additional risk of contracting the disease.

Outcome of cardiopulmonary resuscitation in a pediatric cardiac intensive care unit

OBJECTIVE

To determine the eventual outcome of children with heart disease who had cardiopulmonary resuscitation (CPR) in a specialized pediatric cardiac intensive care unit (CICU), and to define the influence of any prearrest variables on the outcome.

DESIGN

A retrospective review of patients' medical records.

SETTING

A pediatric CICU of a tertiary pediatric teaching hospital.

PATIENTS AND METHODS

Patients were all children who presented with cardiopulmonary arrest and who were administered CPR in the pediatric CICU between June 1995 and June 1997. Prearrest variables such as age, diagnosis, prior cardiac surgery, and inotropic support with epinephrine, as well as cause of arrest, were evaluated.

MEASUREMENTS AND MAIN RESULTS

Thirty-two patients, ranging in age from 1 day to 21 yrs (median, 1 month), satisfied criteria for inclusion in the study group. These 32 patients had a total of 38 episodes of cardiopulmonary arrest. Twenty-five of these patients (78%) had cardiac surgery before arrest. Inotropic support with continuous infusion of epinephrine was being administered at the time of arrest in 18 of 38 (47%) arrests. These prearrest variables did not influence outcome of CPR. Of the 38 episodes of CPR, 24 episodes (63%) were successful, with 20 episodes resulting in return of spontaneous circulation and four patients being successfully placed on mechanical cardiopulmonary support. Fourteen children, including all four patients who were rescued with mechanical cardiopulmonary support, survived to discharge. At 6-month follow-up, 11 patients were still alive, with three having neurologic impairment.

CONCLUSIONS

After cardiopulmonary resuscitation in this pediatric CICU, the rate of success was 63% and the rate of survival was 42%. Prior cardiac surgery and use of epinephrine before arrest did not influence the outcome of CPR. The availability of effective mechanical cardiopulmonary support can improve the outcome of CPR.

Interresponse times in serial recall: effects of intraserial repetition

The authors examined the effects of intraserial repetition on multitrial serial learning of random consonant lists, analyzing both learning rates and perfect trial interresponse times (IRTs). Lists varied along 3 dimensions: list length, presence or absence of a repeated element, and lag between repeated elements. After achieving a forward-recall criterion on a given list, participants (N = 20) attempted backward recall. At small lags, IRTs between the repeated elements were very short (compared with IRTs from identical positions in nonrepetition lists). At larger lags, the IRT to recall the second repeated item was substantially longer than in control lists. These results reveal a latency analogue of the Ranschburg pattern seen in accuracy data. A Ranschburg pattern was also found in participants' learning rates. These results both generalize the Ranschburg phenomenon and present further challenges to theories of serial order memory.

Acoustic and mechanical properties of artificial stones in comparison to natural kidney stones

PURPOSE

Standardized and reproducible artificial kidney stone models are important for performing comparative studies of different lithotripsy modalities. The acoustic and mechanical properties of renal calculi dictate the manner by which stones interact with the mechanical stresses produced by shock wave lithotripsy (SWL) or intracorporeal lithotripsy modalities. We have developed a novel artificial kidney stone model that is made of natural substances found in real kidney stones. These stone models appear to be much closer in physical properties to natural kidney stones than previously used stone models.

MATERIALS AND METHODS

The acoustic and mechanical properties of six groups of artificial stone models were compared to corresponding natural stones of similar compositions. Moreover, three groups of artificial stone models made of plaster-of-Paris were compared to their natural counterparts. In terms of acoustic properties, stone density was measured using a pycnometer based on Archimedes' principle, whereas longitudinal and transverse (or shear) wave propagation speeds were measured using an ultrasound pulse transmission technique. These values were used to calculate wave impedance and dynamic mechanical properties (bulk modulus, Young's modulus, and shear modulus) of the stones. The microhardness of the stones was measured and the effect of composition on stone fragility was evaluated.

RESULTS

Artificial stones, when compared to natural stones of similar composition, showed similar trends in longitudinal and transverse wave speeds, wave impedance, and dynamic elastic moduli. However, values for the artificial stones were uniformly low compared to those of natural stones, suggesting that these artificial stones may be more amenable to shock wave fragmentation. The results of SWL on stone fragmentation of artificial and natural stones also revealed similar trends with the exception of artificial cystine stones which were found to be the most resistant to shock wave fragmentation.

CONCLUSIONS

The results indicate that the physical properties of artificial stones made of natural stone materials are comparable to renal calculi of the same chemical composition. The data suggests that these stone phantoms are suitable for performing standardized and reproducible in vitro investigations, especially with regards to fragility of kidney stones of different chemical compositions during SWL.

Remifentanil in the horse: identification and detection of its major urinary metabolite

Remifentanil (4-methoxycarbonyl-4-[(1-oxopropyl)phenylamino]-1-piperidinepropionic acid methyl ester) is a mu-opioid receptor agonist with considerable abuse potential in racing horses. The identification of its major equine urinary metabolite, 4-methoxycarbonyl-4-[(1-oxopropyl)phenylamino]-1-piperidinepropionic+ ++ acid, an ester hydrolysis product of remifentanil is reported. Administration of remifentanil HCl (5 mg, intravenous) produced clear-cut locomotor responses, establishing the clinical efficacy of this dose. ELISA analysis of postadministration urine samples readily detected fentanyl equivalents in these samples. Mass spectrometric analysis, using solid-phase extraction and trimethylsilyl (TMS) derivatization, showed the urine samples contained parent remifentanil in low concentrations, peaking at 1 h. More significantly, a major peak was identified as representing 4-methoxycarbonyl-4-[(1-oxopropyl)phenylamino]-1-piperidinepropionic+ ++ acid, arising from ester hydrolysis of remifentanil. This metabolite reached its maximal urinary concentrations at 1 h and was present at up to 10-fold greater concentrations than parent remifentanil. Base hydrolysis of remifentanil yielded a carboxylic acid with the same mass spectral characteristics as those of the equine metabolite. In summary, these data indicate that remifentanil administration results in the appearance of readily detectable amounts of 4-methoxycarbonyl-4-[(1-oxopropyl)phenylamino]-1-piperidinepropionic+ ++ acid in urine. On this basis, screening and confirmation tests for this equine urinary metabolite should be optimized for forensic control of remifentanil.

Smoking as a risk factor for accident death: a meta-analysis of cohort studies

This meta-analysis discusses the consistency, strength, dose-response, independence, and generalizability of published cohort data on accident death relative risks in smokers. To locate data, three authors independently searched MEDLINE, and bibliographies of the pertinent studies found, for data which allowed estimation of an appropriate cigarette smoker accident death relative risk (and 95% confidence interval). Relative risks and dose-response were summarized by fixed effects and Poisson modeling, respectively. Four pertinent cohort studies including eight populations were located. Cigarette smoking predicted summary accident death relative risks of 1.51 (95% confidence interval 1.27-1.78) versus never smokers and 1.35 (1.17-1.57) versus ex-smokers. Summary dose-response trends were significant (P = 0.0000) versus never or least smoking referents. In individual studies, the smoking/accident death association persisted after adjustment or, in effect stratification, for age, race, sex, and occupation; occupation and time period; or numerous cardiac risk factors. This meta-analysis found significant, consistent, dose-response, often strong and independent (of age, race, and sex), prospective associations of smoking with accident death, internationally. Further studies and warnings of the smoking/accident death associations seem merited.

Homeopathic treatment of acute childhood diarrhea: results from a clinical trial in Nepal

OBJECTIVE

To investigate whether the finding in a previous study that homeopathic medicines decrease the duration of acute diarrhea in children could be replicated in a different study population.

DESIGN

Randomized, double-blind, placebo-controlled trial.

SETTING

Private, charitable health clinic in Kathmandu, Nepal.

SUBJECTS

A consecutive sample of 126 children, 6 months to 5 years of age, who presented during April through June, 1994, with more than three unformed stools in the previous 24 hours.

INTERVENTION

Children received either an individualized homeopathic medicine or placebo, to be taken one dose after each unformed stool for 5 days. Parents recorded daily stools on diary cards, and health workers made home visits daily to monitor children.

OUTCOME MEASURES

Predefined measures were based on the previous study: (1) duration of diarrhea, defined as the time until there were fewer than three unformed stools per day, for two consecutive days, and (2) Average number of stools per day for each group.

RESULTS

Of the 126 children initially enrolled, 116 completed treatment. The mean number of stools per day over the entire 5-day treatment period was 3.2 for the treatment group and 4.5 for the placebo group (P = 0.023). A Kaplan-Meier survival analysis of the duration of diarrhea, which included data from all patient visits, showed an 18.4% greater probability that a child would be free of diarrhea by day 5 under homeopathic treatment (P = 0.036).

CONCLUSIONS

These results are consistent with the finding from the previous study that individualized homeopathic treatment decreases the duration of diarrhea and number of stools in children with acute childhood diarrhea.

Symptoms associated with infant teething: a prospective study

CONTEXT

Studies of infant teething have been retrospective, small, or conducted on institutionalized infants.

OBJECTIVES

To conduct a large, prospective study of healthy infants to determine which symptoms may be attributed to teething and to attempt to predict tooth emergence from an infant's symptoms.

DESIGN

Prospective cohort. Setting. Clinic-based pediatric group practice.

PATIENTS

One hundred twenty-five consecutive well children of consenting Cleveland Clinic employees.

OUTCOME MEASURES

Parents daily recorded 2 tympanic temperatures, presence or absence of 18 symptoms, and all tooth eruptions in their infants, from the 4-month well-child visit until the child turned 1 year old.

RESULTS

Daily symptom data were available for 19 422 child-days and 475 tooth eruptions. Symptoms were only significantly more frequent in the 4 days before a tooth emergence, the day of the emergence, and 3 days after it, so this 8-day window was defined as the teething period. Increased biting, drooling, gum-rubbing, sucking, irritability, wakefulness, ear-rubbing, facial rash, decreased appetite for solid foods, and mild temperature elevation were all statistically associated with teething. Congestion, sleep disturbance, stool looseness, increased stool number, decreased appetite for liquids, cough, rashes other than facial rashes, fever over 102 degrees F, and vomiting were not significantly associated with tooth emergence. Although many symptoms were associated with teething, no symptom occurred in >35% of teething infants, and no symptom occurred >20% more often in teething than in nonteething infants. No teething child had a fever of 104 degrees F and none had a life-threatening illness.

CONCLUSIONS

Many mild symptoms previously thought to be associated with teething were found in this study to be temporally associated with teething. However, no symptom cluster could reliably predict the imminent emergence of a tooth. Before caregivers attribute any infants' signs or symptoms of a potentially serious illness to teething, other possible causes must be ruled out.teething, tooth eruption, teeth, deciduous dentition.

Evaluation of an Australian miscarriage support programme

Miscarriage is a frequent and distressing event for women who often require admission to a gynaecology unit for the evacuation of the products of conception. Most women are admitted for day surgery or an overnight stay. The short time frame limits the time nursing staff have to provide support and information for women who have experienced loss through miscarriage. This article presents the qualitative evaluation of a telephone follow-up service provided as part of the Miscarriage Support Programme of Care conducted by staff of the gynaecology inpatient services in an Australian public hospital. The data from this evaluation indicate that miscarriage does have a varying degree of impact on a woman's inpatient experience and emotional recovery. The primary themes of emotional recovery, support after discharge, inpatient experience of care, and usefulness of the literature given to women before discharge, will guide the ongoing development of support and discharge planning by staff of gynaecology inpatient services for women who have experienced miscarriage.

Fixation, polyethylene wear, and pelvic osteolysis in primary total hip replacement

A multicenter retrospective review was performed analyzing 1081 primary total hip replacements in 944 patients using the Harris Galante-I cementless acetabular component with screw fixation. All patients were followed up for a minimum of 5 years with a mean followup of 81 months. Linear polyethylene wear averaged 0.11 mm/year (range, 0-0.86 mm/year). Pelvic osteolysis was seen in 25 patients (2.3%). Migration of the acetabular component was seen in four hips. A subgroup of patients was reanalyzed at a minimum followup of 10 years. The mean linear polyethylene wear rate remained 0.11 mm/year. In this group, only one socket had migrated. There was an association between wear rate and age. On average, younger patients had higher wear rates. The risk for having pelvic osteolysis develop and the need for revision surgery also was age-related. Twenty-two percent of hip replacements (15 hips) in patients younger than 50 years of age at the time of their index operation had pelvic osteolysis develop. In contrast, for patients older than 50 years of age at the time of surgery only 7.8% (eight hips) had osteolysis of the pelvis develop. For patients older than 70 years of age at the time of primary total hip replacement, none had pelvic osteolysis develop.

Diclazuril in the horse: its identification and detection and preliminary pharmacokinetics

Diclazuril (4-chlorophenyl [2,6-dichloro-4-(4,5-dihydro-3H-3,5-dioxo-1,2,4-triazin-2-yl)pheny l] acetonitrile), is a benzeneacetonitrile antiprotozoal agent (Janssen Research Compound R 64433) marketed as Clinacox . Diclazuril may have clinical application in the treatment of Equine Protozoal Myeloencephalitis (EPM). To evaluate its bioavailability and preliminary pharmacokinetics in the horse we developed a sensitive quantitative high-pressure liquid chromatography (HPLC) method for diclazuril in equine biological fluids. MS/MS analysis of diclazuril in our HPLC solvent yielded mass spectral data consistent with the presence of diclazuril. After a single oral dose of diclazuril at 2.5 g/450 kg (as 500 g Clinacox), plasma samples from four horses showed good plasma concentrations of diclazuril which peaked at 1.077 +/- 0.174 microg/mL (mean +/- SEM) with an apparent plasma half-life of about 43 h. When this dose of Clinacox was administered daily for 21 days to two horses, mean steady state plasma concentrations of 7-9 microg/mL were attained. Steady-state levels in the CSF ranged between 100 and 250 ng/mL. There was no detectable parent diclazuril in the urine samples of dosed horses by HPLC or by routine postrace thin layer chromatography (TLC). These results show that diclazuril is absorbed after oral administration and attains steady-state concentrations in plasma and CSF. The steady state concentrations attained in CSF are more than sufficient to interfere with Sarcocystis neurona, whose proliferation is reportedly 95% inhibited by concentrations of diclazuril as low as 1 ng/mL. These results are therefore entirely consistent with and support the reported clinical efficacy of diclazuril in the treatment of clinical cases of EPM.

The relationships among environmental allergen sensitization, allergen exposure, pulmonary function, and bronchial hyperresponsiveness in the Childhood Asthma Management Program

BACKGROUND

Sensitivity and exposure to indoor allergens constitutes a risk factor for the development and persistence of asthma in children.

OBJECTIVE

Our purpose was to evaluate the relationship between sensitivity and exposure to inhalant allergens and lung function and bronchial responsiveness in a group of children (n = 1041) aged 8.9 +/- 2.1 years with mild to moderate asthma enrolled in the Childhood Asthma Management Program (CAMP).

METHODS

With use of the extensive CAMP baseline cross-sectional data on spirometry, bronchial responsiveness, allergen sensitivities, and household allergen levels, the relationship of sensitization and exposure to allergens to lung function and methacholine sensitivity was evaluated. Children who enrolled in CAMP stopped all antiasthma medication except rescue use of albuterol and prednisone for exacerbations during the 5- to 16-week screening period. During the last 2 of these weeks they underwent spirometry and methacholine challenge. Indoor allergen exposures were determined from questionnaires completed by the parent. Household levels of indoor allergens (mite, cat, dog, cockroach, mold) were determined on house dust samples. Allergen sensitivity was determined by percutaneous skin testing with a standard battery of allergens plus locally important pollen and fungal spores. Lung function and bronchial hyperresponsiveness were compared for children sensitive and not sensitive to both indoor and outdoor allergens on skin testing and, if sensitive, for exposed and not exposed to the allergens to which they were positive on skin testing.

RESULTS

There was a strong direct correlation between increased sensitivity to inhaled methacholine and skin test sensitivity to tree, weed, Alternaria, cat, dog, and indoor molds. When the relationship was examined by stepwise regression, the skin test sensitivities showing the strongest associations with the concentration of methacholine that caused a 20% fall in FEV(1) were dog (P =.003), Alternaria (P =.01), and cat (P =.05). Children sensitive to any one of the aeroallergens tested were compared for the presence or absence of exposure to that allergen at the time that the methacholine challenge was performed. Those who were sensitive and exposed to weed and cat had greater methacholine sensitivity than those similarly sensitive but not exposed (P =.003 and P =.02, respectively).

CONCLUSIONS

Sensitivity to dog or cat dander or Alternaria by skin testing was associated with increased bronchial responsiveness but not decreased lung function in children with mild to moderate asthma. These findings support the important role that sensitization to certain allergens plays in modulating bronchial responsiveness.

The impact of potent antiretroviral therapy on the characteristics of hospitalized patients with HIV infection

OBJECTIVE

Despite advances in antiretroviral treatment, a large number of HIV-infected patients still require hospitalization. This study describes the characteristics of HIV patients requiring hospitalization before and after the advent of potent antiretroviral therapies.

METHODS

Information was collected on all HIV-positive patients admitted to the New York Hospital-Cornell Medical Center in New York City. Data was collected from 1 January through 30 June 1995, and during the same 6-month interval in 1997.

RESULTS

In each time period over 1500 outpatients were receiving treatment for HIV infection. There was a significant decrease in the incidence of admission [60.4 per 100 patient-years (PY) in 1995, 28.8 per 100 PY in 1997], and length of stay (10 versus 8 days). The median CD4 cell count of all HIV-infected patients admitted to the hospital doubled: 37 x 10(6)/l in 1995 versus 80 x 10(6)/l in 1997. However, there was no significant change in the median CD4 cell count of patients diagnosed with opportunistic infections. The incidence of the most common diagnosis (bacterial pneumonia, 8.0 per 100 PY in 1995 versus 3.6 per 100 PY in 1997) and the most common opportunistic infection (Pneumocystis carinii pneumonia 7.6 per 100 PY in 1995 versus 2.4 per 100 PY in 1997) decreased significantly.

CONCLUSIONS

Since the introduction of potent antiretroviral therapy, a significant decrease in the incidence of hospital admission and opportunistic infections has occurred. There has been a doubling of the median CD4 cell count of inpatients. There has been no significant change in the median CD4 cell count at which patients present with opportunistic infections.

Test characteristics of acridine orange, Gram, and May-Grünwald-Giemsa stains for enumeration of intracellular organisms in bronchoalveolar lavage fluid

For enumeration of intracellular organisms (ICO) in bronchoalveolar lavage fluid samples, the May-Grünwald-Giemsa (MGG) stain displayed higher interobserver agreement than the acridine orange and Gram stains. The MGG stain offered a reliable enumeration of ICO when 200 cells were counted by one observer.