Environmental impact on pediatric epistaxis and the utility of diagnostic studies: A single-institutional review

OBJECTIVES

Pediatric epistaxis is a multifactorial disease entity. The objective of this study is to determine the socioeconomic and air-quality contributions to pediatric epistaxis. The study also evaluates the utility of diagnostic lab work as a predictor of bleeding rates and need for operative intervention.

METHODS

A case series of pediatric patients treated in an outpatient Otolaryngology clinic at a tertiary care children's hospital in 2021 for epistaxis was performed. Patients with nasal bone trauma (n = 8), consult while inpatient (n = 7), and those with nasal masses (n = 2) were excluded; 181 patients met inclusion criteria. Demographic, clinical, socioeconomic, and air quality (tropospheric ozone, particulate matter) data were recorded. Associations with persistent bleeding and operative interventions were evaluated using logistic regression, Wilcoxon rank-sum, and Spearman rank correlation.

RESULTS

Of the 181 patients, 75 (41.4%) were female. Forty-six of 181 (25.4%) had associated allergic symptoms. Twenty-six patients had allergy testing; 14/26 (53.8%) of these had positive results. Re-bleeding was more common in those with allergic symptoms (OR: 2.42, 95% CI: 1.22-4.78, p = 0.01). Patients with re-bleeding lived in counties with more days with ozone over the US standard (median 5 days, range 0-32 days) compared with those with no re-bleeding (median 3 days, range 0-32 days, p = 0.007). There was also an association between the number of visits for re-bleed and percent below poverty level (ρ = 0.259, p = 0.03) as well as the number of days with particulate matter levels over the US standard (ρ = 0.343, p = 0.01). Coagulopathy was present in 9/54 (16.7%) patients, with the majority being Von Willebrand disease (5/54, 9.3%). Easy bruising was not significantly associated with positive lab results.

CONCLUSIONS

Environmental pollution, living in a zip code with more residents below the poverty level, and allergic rhinitis were positively associated with recurrent epistaxis. Understanding the geographic background of presenting patients may help direct workup and treatment options.

Cost analysis of sialendoscopy for the treatment of salivary gland disorders in children

INTRODUCTION

Recent advances in Otolaryngology have changed the diagnosis and therapy for salivary gland disorders. Sialendoscopy-assisted surgery is a minimally invasive, conservative procedure for functional preservation of the affected gland. The goals of this study are to assess the indications, use, and outcomes of pediatric sialendoscopy at a tertiary pediatric institution as well as to analyze the direct cost related to the diagnosis and treatment of patients with sialolithiasis and Juvenile Recurrent Parotitis managed with sialendoscopy.

METHODS

Retrospective cohort study of pediatric patients undergoing diagnostic and/or therapeutic sialendoscopy at a tertiary level children's hospital between 2012 and 2020. Demographic, clinical, surgical variables and direct hospital costs 1 year before and after the sialendoscopy procedure were collected and analyzed.

RESULTS

Twenty-two pediatric patients were included. There was male predominance (59.3%). The most common indication for sialendoscopy was Juvenile Recurrent Parotitis. Average age of onset was 6.5 years for patients with JPR and 14.2 years for patients with sialolithiasis. All patients had an average of 4.5 episodes before the first procedure. 8 patients required repeat sialendoscopy for recurrent symptoms. Mean total hospital costs were significantly higher in patients with JRP 1 year before and after the sialendoscopy ($4308.8 vs. $3330) compared to patients with sialolithiasis. Costs of the sialendoscopy and related expenses including anesthesia and PACU cost were similar in both studied groups ($13,506 vs. $13,022.9). Complete resolution of symptoms was achieved in 14 patients with JRP and all patients with sialolithiasis.

CONCLUSION

Sialendoscopy is a low-risk procedure that aids in the treatment for pediatric salivary gland disorders. The costs related to sialendoscopy are substantial and patients with JRP incur higher hospital preoperative and postoperative costs compared to patients with sialolithiasis.

Clinical and Radiologic Characterization of Frontal Sinusitis in the Pediatric Population

INTRODUCTION

Frontal sinusitis in the pediatric population is a disease that has not been thoroughly studied or characterized. The goals of this study are to characterize the clinical presentation, radiologic variables, treatment modalities, complications, and prognosis associated with acute and chronic frontal sinus disease in the pediatric population.

METHODS

IRB-approved retrospective cohort study of pediatric patients who were diagnosed with acute (AFS) or chronic frontal sinusitis (CFS) and underwent frontal sinus surgery at a tertiary level Children's Hospital from 2006 to 2016. Patients with AFS were compared to patients with CFS. Statistical analysis completed using chi-square test or Fisher's exact test, statistical significance set at P < .05.

RESULTS

A total of 19 patients with AFS and 15 patients with CFS were analyzed. There was a male predominance in AFS and female predominance in CFS (P < .05).AFS patients were less likely to have allergies, prior sinus disease, or significant comorbidities (P < .05).Additionally, AFS patients presented with constitutional, neurologic, and ocular symptoms. The CFS group had predominantly sinonasal symptoms. CT-scan analysis showed that AFS patients had higher prevalence of complex frontal anatomy (Type-II cells, concha bullosa) compared with CFS patients (P < .05). Culture results were positive in 78% of the AFS group, with S. Anginosus (53%), Anaerobes (20%), and normal flora (17%). In the CFS group cultures were positive in 60% of the patients, 56% grew normal flora, 13% H. Influenzae, 6.5% Pseudomonas, and 24.5% other species. CFS patients were more likely to have persistent sinus disease and require repeat sinus procedures (P < .05).

CONCLUSION

There are 2 distinct presentations of frontal sinus disease in the pediatric population. Patients with AFS vary significantly from those with CFS. Males, ages 13 to 18 years old, who cultured positive for S. Anginosus (former S.Milleri) dominated the AFS subgroup. Whereas as female patients with a history of allergic rhinitis and muco-cilliary disease were more prominent in the CRS subgroup. Correct identification and understanding of these 2 different entities are crucial for the appropriate short and long-term patient management.

The Pediatric Sinus Staging System: A Computed Tomography-Based Approach to Grading Pediatric Sinus Disease

OBJECTIVES/HYPOTHESIS

Pediatric chronic rhinosinusitis (CRS) is a prevalent disease with few objective measurements available to predict which patients will require surgical intervention. The Lund-Mackay (LM) score for computed tomography (CT) scans is one objective data point available for the adult population; however, a dedicated scoring system in the pediatric population has not been popularized. We present a Pediatric Sinus Staging System (PSSS) that considers both opacification and the varying developmental stages of each sinus.

STUDY DESIGN

Retrospective chart review.

METHODS

We analyzed CT scans of pediatric patients with a diagnosis of CRS. Both LM and PSSS scores were calculated for each scan. Groups were formed based on treatment outcomes and included patients who were treated successfully with medical therapy and/or adenoidectomy (med/adenoid), patients who required functional endoscopic sinus surgery (FESS), and patients who required revision FESS.

RESULTS

Overall, 76 patient scans were reviewed. PSSS values were significantly less than LM for the control group (P = .001) and significantly higher for patients with cystic fibrosis (P = .027) and with CRS with polyps (P = .001). The ideal cutoff for PSSS to distinguish between med/adenoid and single FESS treatment with a sensitivity 90.6% and specificity of 50.0% was ≥2.

CONCLUSIONS

The PSSS gives a more descriptive score by accounting for the opacification and pneumatization of each sinus. Our current results show similar values between PSSS and LM scores, which suggests internal validity. In addition, a PSSS score of ≥2 may help physicians better counsel families on the likelihood of requiring FESS. Further investigation is needed to fully validate the PSSS.

LEVEL OF EVIDENCE

3b Laryngoscope, 131:E642-E648, 2021.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Exploring contrary trends in bladder cancer incidence, mortality and survival: implications for research and cancer control

AIM

To investigate trends in bladder cancer incidence, mortality and survival, and cancer-control implications.

METHODS

South Australian Registry data were used to calculate age-standardized incidence and mortality rates from 1980 to 2004. Sociodemographic predictors of invasive as opposed to in situ disease were examined. Determinants of disease-specific survival were investigated using Kaplan-Meier estimates and proportional hazards regression.

RESULTS

Incidence rates for invasive cancers decreased by 21% between 1980-84 and 2000-04, similarly affecting men and women. Meanwhile increases occurred for combined in situ and invasive disease. While mortality rates decreased by approximately a third in men and women less than 70 years of age after the early 1990 s, no changes were evident for older residents. The proportion of cancers found at an in situ stage was higher in younger ages and more recent diagnostic periods. Five-year survivals of invasive cases decreased from 64% for 1980-84 diagnoses to 58% for 1995-2004. Multivariable analysis showed that diagnostic period was not predictive of survival after age adjustment (P= 0.719), with lower survival relating to older age, transitional compared with papillary transitional cancers, female sex, indigenous status and a country as opposed to metropolitan residence.

CONCLUSIONS

Reductions in invasive disease incidence may be due to increased detection at an in situ stage. The decline in survival from invasive disease in more recent periods is explained by increased age at diagnosis. Poorer outcomes of invasive cases remain for women after adjusting for age, histology, indigenous status and residential location.

Targeted prostate cancer screening in men with mutations in BRCA1 and BRCA2 detects aggressive prostate cancer: preliminary analysis of the results of the IMPACT study

OBJECTIVE

To evaluate the role of targeted prostate cancer screening in men with BRCA1 or BRCA2 mutations, an international study, IMPACT (Identification of Men with a genetic predisposition to ProstAte Cancer: Targeted screening in BRCA1/2 mutation carriers and controls), was established. This is the first multicentre screening study targeted at men with a known genetic predisposition to prostate cancer. A preliminary analysis of the data is reported.

PATIENTS AND METHODS

Men aged 40-69 years from families with BRCA1 or BRCA2 mutations were offered annual prostate specific antigen (PSA) testing, and those with PSA > 3 ng/mL, were offered a prostate biopsy. Controls were men age-matched (± 5 years) who were negative for the familial mutation.

RESULTS

In total, 300 men were recruited (205 mutation carriers; 89 BRCA1, 116 BRCA2 and 95 controls) over 33 months. At the baseline screen (year 1), 7.0% (21/300) underwent a prostate biopsy. Prostate cancer was diagnosed in ten individuals, a prevalence of 3.3%. The positive predictive value of PSA screening in this cohort was 47·6% (10/21). One prostate cancer was diagnosed at year 2. Of the 11 prostate cancers diagnosed, nine were in mutation carriers, two in controls, and eight were clinically significant.

CONCLUSIONS

The present study shows that the positive predictive value of PSA screening in BRCA mutation carriers is high and that screening detects clinically significant prostate cancer. These results support the rationale for continued screening in such men.

Extra-esophageal acid reflux induced adenotonsillar hyperplasia: case report and literature review

The etiology of adenotonsillar hyperplasia is not well understood. A 3-year-old child presented with obstructive sleep apnea believed to be secondary to enlarged tonsils and adenoids. Subglottic stenosis was encountered during intubation; the adenotonsillectomy was cancelled. Severe extra-esophageal reflux was identified and treated. At follow-up endoscopy 3 weeks later, the tonsils and adenoids were no longer enlarged or obstructing the airway. The role of extra-esophageal reflux in the pathogenesis adenotonsillar hyperplasia is discussed.

Outcome of post-prostatectomy radiotherapy in one institution

We present a retrospective study to evaluate the outcome of postoperative radiotherapy for biochemical or clinical recurrent prostate cancer. Twenty-six patients (median age 60 years) underwent radiotherapy after radical prostatectomy between January 1997 and January 2004. Seven patients received adjuvant radiotherapy and 19 received salvage radiotherapy. The median prostate-specific antigen at diagnosis was 8.6 (0.9-89) and most (23 patients) presented with T(3)N(0) disease. The median follow up was 19.5 months (5-84 months). All patients received a dose of 61.2 Gy at 1.8 Gy per fraction, 20 initially receiving 45 Gy to the lesser pelvis. The median dose to the bladder, rectum and left femoral head were 55.6, 57.5 and 33.8 Gy, respectively. All patients were managed radiotherapeutically by the first author. Twenty-four patients are alive. Two patients have died, one from oesophageal cancer and the second from metastatic prostate cancer. Two other patients also developed metastatic disease. Four asymptomatic patients with a rising prostate-specific antigen are under observation. None of the 26 patients has developed a local recurrence. Seven patients have developed grade 1 late bowel effects and three a grade 2 late effect. Eight patients suffer from grade 1 late genitourinary effects and two from grade 2 effects. One patient developed impotence, whereas 23 patients were rendered impotent postoperatively. There were no grade 3/4 late effects. Postoperative radiotherapy is well tolerated and provides effective local control.

Variation in Frequency of the Virulence‐Factor Gene inEscherichia coliClones Colonizing the Stools and Urinary Tracts of Healthy Prepubertal Girls

To provide information on virulence expression of Escherichia coli in healthy hosts, stool, periurethral, and urine samples were collected weekly from healthy 3-6-year-old girls who lived in a small rural community. Dominant and nondominant clones were defined in stool specimens, and the expression of virulence factors was determined. We found that healthy girls commonly shared dominant clones. P adhesin, hemolysin, and type I adhesin were commonly found in clones in the stool and in clones in the urinary tract. In addition, expression of virulence factors, among both dominant and nondominant clones in the stool, changed from week to week. The presence of P adhesin was a marker for the persistence of a dominant clone in the stool and was associated with an increased likelihood that a nondominant clone would be detected in the urinary tract. Type I adhesin was ubiquitous among stool strains, with orientation of the fimbrial switch being both in the "off" position and in both the "on" and "off" positions. In summary, the intestinal flora of healthy girls is complex, with frequent changes in virulence expression.

Clonal relationships and extended virulence genotypes among Escherichia coli isolates from women with a first or recurrent episode of cystitis

To identify bacterial predictors of recurrence and/or persistence in acute cystitis, extended virulence genotypes were compared with clonal background and epidemiologic status among 74 Escherichia coli urine isolates from women with first or recurrent episodes of urinary tract infection (UTI). Sequential isolates from patients with recurrent UTI were classified, using macrorestriction analysis, as having caused an isolated recurrence versus a single or multiple same-strain recurrences. papA, papG allele II, iha, and iutA predicted multiple same-strain recurrences, whereas nfaE and the absence of sfaS or fyuA predicted isolated recurrences. Phylogenetic group B2 accounted for 70% of isolates and for most of the putative virulence factors (VFs) studied. The meningitis-associated O18:K1:H7 clonal group comprised 18% of isolates, exhibited multiple VFs, and caused "once-only" recurrences less commonly than did other strains. These findings identify specific VFs and clonal groups against which preventive interventions might be beneficial and illustrate the importance of delineating pathogenetically relevant subgroups within the "recurrent cystitis" population.

Effects of vaginal intercourse with and without a condom on vaginal flora and vaginal epithelium

Effects of a single episode of intercourse on vaginal flora and epithelium were examined in subjects randomly assigned to groups that used no condom or lubricated nonspermicide condoms. Subjects were evaluated at visits before (1 month and 1-2 days) and after (8-12 h, 2-3 days, and 6-8 days) an index episode of sexual intercourse. The 22 subjects who used no condoms had significantly more Escherichia coli and a high concentration (> or =10(5) cfu/mL) of E. coli in the vagina (both, P<.001) and urine (all <10(5) cfu/mL; P=.004) at visit 3 than at visits 1 and 2. The 20 subjects who used condoms had a trend toward more vaginal E. coli (P=.06) and a significant increase in other enteric gram-negative rods (P=.001) after intercourse. Intercourse was not associated with gross, colposcopic, or histologic vaginal epithelial abnormalities.

Effects of oral contraceptive pill use on vaginal flora and vaginal epithelium

The objective of this study was to examine the effect of oral contraceptive (OC) use on vaginal discharge, epithelium, and flora. Thirty women who planned to use OC for contraception were evaluated before and 2 months after the start of OC use. At both visits, genital symptoms and exposures were assessed by questionnaire; vaginal signs were assessed by speculum examination and colposcopy; vaginal microflora was evaluated by quantitative culture; and a vaginal biopsy was obtained for histopathologic evaluation. Variables were compared between the initial visit and after 2 months of OC use. It was found that OC use did not change the gross, colposcopic, or histologic appearance of the vaginal epithelium or characteristics of vaginal or cervical discharge. Vaginal flora essentially remained unchanged after 2 months of OC use, except that a small decrease occurred in the number of subjects with > or =10(5) colony forming units/mL of H(2)O(2) producing Lactobacillus from 16 at baseline to 9 (p = 0.04) and in the total number of subjects with Ureaplasma urealyticum from 17 at baseline to 10 of 29 (p = 0.04). The results indicate minimal effect of OC use on the vaginal epithelium and vaginal and cervical discharge, and a small effect on vaginal flora.

Expression of virulence factors among Escherichia coli isolated from the periurethra and urine of children with neurogenic bladder on intermittent catheterization

BACKGROUND

Patients with neurogenic bladder caused by spinal cord injury or myelomeningocele empty their bladder several times a day by intermittent catheterization. Bacteriuria without symptoms of infection is frequently present in these patients. Occasionally a clone of Escherichia coli that has been carried for weeks without symptoms causes a symptomatic urinary tract infection. Virulence factors are commonly expressed among E. coli causing infection in patients with normal urinary tracts. However, it is unknown whether expression of virulence factors by an E. coli clone colonizing the neurogenic bladder increases the risk of subsequent infection. In this study we examined the prevalence of virulence factor expression among E. coli isolated from the periurethra and urine of patients with neurogenic bladder.

METHODS

The prevalence of virulence factors was examined among E. coli isolated from the periurethra and urine in patients with neurogenic bladder who received intermittent catheterization and were followed for 6 months. Representative isolates from the 37 clonal types of E. coli detected in the periurethra and urine of children with neurogenic bladder were assessed for O antigen, hemolysin, aerobactin, serum resistance and type I and P-adhesin.

RESULTS

All clones were serum-resistant and expressed type I adhesin, none expressed aerobactin and two expressed hemolysin. The presence of P-adhesin was not unique to clones associated with symptomatic infection. The presence of P-adhesin carried for weeks in a clone did not predict subsequent infection in the neurogenic bladder.

CONCLUSION

Bacterial virulence factors did not predict infection of the neurogenic bladder.

Host factors in susceptibility to urinary tract infections

In summary, a variety of intrinsic and acquired factors influence the risk of RUTI in otherwise normal women, including history of prior UTIs, the woman's genetic background, and exposures to spermicides, sexual activity and antibiotics. Further studies are directed towards understanding the interplay between these factors and their relative importance among various subpopulations of women with RUTI, such as otherwise healthy pre- and post-menopausal women.

Biochemical separations by continuous-bed chromatography

Innovations in column-packing media for biomolecule purification have progressed from large spherical, porous polysaccharide beads to advanced polymeric supports. Continuous-bed technology is a radical new technology for chromatography based on the polymerization of advanced monomers and ionomers directly in the chromatographic column. The polymer chains form aggregates which coalesce into a dense, homogeneous network of interconnected nodules consisting of microparticles with an average diameter of 3000 A. The voids or channels between the nodules are large enough to permit a high hydrodynamic flow. Due to the high cross-linking of the polymer matrix, the surface of each nodule is nonporous yet the polymeric microparticles provide a very large surface area for high binding capacity. This paper will demonstrate the properties and advantages of using a continuous bed support for high resolution biomolecule separations at high flow-rates without sacrificing capacity.

Comparison of Escherichia coli strains recovered from human cystitis and pyelonephritis infections in transurethrally challenged mice

Urinary tract infection, most frequently caused by Escherichia coli, is one of the most common bacterial infections in humans. A vast amount of literature regarding the mechanisms through which E. coli induces pyelonephritis has accumulated. Although cystitis accounts for 95% of visits to physicians for symptoms of urinary tract infections, few in vivo studies have investigated possible differences between E. coli recovered from patients with clinical symptoms of cystitis and that from patients with symptoms of pyelonephritis. Epidemiological studies indicate that cystitis-associated strains appear to differ from pyelonephritis-associated strains in elaboration of some putative virulence factors. With transurethrally challenged mice we studied possible differences using three each of the most virulent pyelonephritis and cystitis E. coli strains in our collection. The results indicate that cystitis strains colonize the bladder more rapidly than do pyelonephritis strains, while the rates of kidney colonization are similar. Cystitis strains colonize the bladder in higher numbers, induce more pronounced histologic changes in the bladder, and are more rapidly eliminated from the mouse urinary tract than pyelonephritis strains. These results provide evidence that cystitis strains differ from pyelonephritis strains in this model, that this model is useful for the study of the uropathogenicity of cystitis strains, and that it would be unwise to use pyelonephritis strains to study putative virulence factors important in the development of cystitis.

papG alleles of Escherichia coli strains causing first-episode or recurrent acute cystitis in adult women

The distribution of the three alleles of the P adhesin gene papG (classes I-III) was assessed among 74 Escherichia coli urine isolates from women with first-episode or recurrent cystitis, and papG genotype was compared with clinical origin, O serogroup, agglutination of Gal(alpha1-4)Gal-coated latex beads and human or sheep erythrocytes, and hemolysin production. The class-III-only papG genotype (27% of strains) predominated over the I + III (3%) and II-only (7%) genotypes, irrespective of clinical category. In contrast to the class II papG allele, the class III allele was significantly concentrated in serogroups O6 and O18. Agglutination phenotypes corresponded significantly but incompletely with papG genotype, whereas hemolysin production and papG positivity were tightly correlated. These findings suggest that in acute cystitis in adult women, the class III papG allele predominates, confers distinctive agglutination phenotypes, and is restricted to specific E. coli lineages.

Prevention of urinary tract infection

Recurrent UTI remains an exceedingly common clinical problem among women of all ages. Among otherwise healthy premenopausal and postmenopausal women, increased susceptibility to recurrences seems to be conferred by intrinsic host factors, such as nonsecretor genotype or estrogen status, and by exogenous exposures or behaviors, such as use of a diaphragm with spermicide, antimicrobial use, and sexual behavior. The natural history of recurrent UTIs is notable for a temporal clustering phenomenon, the tendency of women to revert to a baseline infection pattern after the cessation of preventive interventions, and repeated serial reinfections of the urinary tract from the fecal reservoir, often by genetically identical organisms. Low-dose antimicrobial regimens given daily, three times weekly, or postcoitally are effective in preventing recurrences in most women with a predisposition to frequent infection. Intermittent patient-initiated self-treatment is an appropriate and effective option in some patients with lower recurrence rates. In postmenopausal women, estrogen replacement therapy, particularly vaginally applied estriol creams, may also significantly reduce the rate of recurrent UTI. Ongoing investigations in the areas of microbial ecology of the vaginal flora, the molecular basis for host-parasite interactions within the urinary tract, and vaccine development may eventually lead to improved means to prevent recurrent urinary tract infections more effectively.

Noninvasive evaluation of coronary artery disease and myocardial viability through stress echocardiography and myocardial perfusion imaging

Today, primary care providers are managing clinical problems that were frequently addressed by a "specialist". Consequently, they must keep current with myriad state-of-the-art diagnostic modalities. In the case of coronary artery disease, knowledge about the reversibility of left ventricular dysfunction conceptualized as "hibernating" and "stunned" myocardium has resulted in an increased utilization of noninvasive cardiac imaging techniques to facilitate clinical decision making. These procedures provide diagnostic and prognostic information about coronary artery disease and left ventricular function beyond that provided by the conventional exercise stress test. The most commonly employed of these are the stress echocardiogram and stress myocardial nuclear perfusion procedures. Both modalities can be performed in conjunction with physical or pharmacologically induced stress, and may be performed on an outpatient basis. Knowledge of how these procedures are performed and the clinical data they provide will facilitate primary care providers as they care for this growing population.

Antecedent antimicrobial use increases the risk of uncomplicated cystitis in young women

To examine whether antecedent antimicrobial use influenced subsequent relative risk of urinary tract infection (UTI) in premenopausal women, data were analyzed from two cohorts of women observed prospectively for 6 months to determine risk factors for UTI. Using a Cox proportional hazards model to adjust for covariates, we found that 326 women in a University cohort and 425 women in a health-maintenance organization cohort were at increased risks for UTI (2.57 [95% confidence interval (CI), 1.24-5.32] and 5.83 [95% CI, 3.17-10.70], respectively) if antimicrobials had been taken during the previous 15-28 days but not during the previous 3, 7, or 14 days. The increased risks were noted both for women whose antimicrobial use was for treatment of a previous UTI and for women who received antimicrobials for other illnesses. These results suggest that recent antimicrobial use increases a woman's risk of UTI, perhaps by altering the indigenous urogenital flora and predisposing to vaginal colonization with uropathogens.

Comparison of expression of virulence factors by Escherichia coli causing cystitis and E. coli colonizing the periurethra of healthy girls

The prevalence of virulence factors possessed by Escherichia coli colonizing the periurethra was examined and compared with that of E. coli causing urinary tract infection. One hundred two E. coli isolates obtained from the periurethra and urine of 7 non-sexually active girls at risk for cystitis were characterized for genetic relatedness and examined for expression of six virulence factors. Expression of virulence factors in colonizing clones of E. coli were compared with expression in clones from symptomatic infection. All virulence factors except P adhesin were commonly expressed by colonizing clones of E. coli that did not go on to infect the urinary tract. Although P adhesin-expressing E. coli were commonly isolated from episodes of cystitis, the presence of P adhesin on periurethral E. coli did not usually predict subsequent infection. By itself, expression of virulence factors on periurethral E. coli is not enough to predict subsequent infection.

Chromosomal restriction fragment length polymorphism analysis of Escherichia coli strains causing recurrent urinary tract infections in young women

To determine whether recurrent, symptomatic urinary tract infections (UTIs) in a given individual are due to the same or different strains, 71 Escherichia coli strains that caused recurrent UTIs were prospectively collected from 23 infection-prone young women and studied by chromosomal restriction fragment length polymorphism (RFLP) analysis using pulsed-field gel electrophoresis. Thirty-five strains from women with first-episode UTIs were also studied. Overall, 30 (68%) of 44 recurrent UTIs were caused by a strain previously identified in that person. In contrast, 32 of 35 strains from first-episode UTIs had unique RFLP profiles. Analysis of a subset of subjects established that the majority of recurrent UTIs were due to reinfection, not persistence of the pathogen within the urinary tract, and suggested that the colonic flora was the reservoir for these reinfecting strains.

Effect of secretor status on vaginal and rectal colonization with fimbriated Escherichia coli in women with and without recurrent urinary tract infection

The prevalence and duration of rectal and vaginal colonization with P- and F-fimbriated Escherichia coli and the relationship of colonization with these strains to blood group secretor status was investigated. Rectal and vaginal E. coli isolates were prospectively collected twice monthly for 6 months from 20 young women with and 20 without a history of recurrent urinary tract infection (UTI). Rectal and vaginal colonization with P- and/or F-fimbriated E. coli was highly prevalent. Nonsecretors who developed UTI during the study period were significantly more likely to be colonized rectally with F-fimbriated E. coli than were the infected secretors (56% vs. 27%; P = .042) or uninfected nonsecretors (56% vs. 31%; P = .046). Persistent vaginal and rectal E. coli colonization with fimbriated organisms occurred commonly in the study patients but was not often temporally associated with the development of UTI. Results suggest that nonsecretors are more susceptible than secretors to colonization with F adhesin-bearing E. coli isolates.

Cloning and expression of soluble epoxide hydrolase from potato

Five cDNAs encoding a putative soluble epoxide hydrolase (sEH) from potato were isolated and characterized. The cDNAs contained open reading frames encoding 36 kDa polypeptides which were highly homologous to the carboxy terminal region of mammalian sEH. When one of the cDNAs was expressed in a baculovirus system a soluble 38 kDa protein with epoxide hydrolase activity was produced. The recombinant enzyme hydrolyzed a commonly used diagnostic substrate for the soluble form of mammalian EH. Inhibitor profiles of the recombinant potato and mammalian sEH were also similar. The expression of sEH in potato was found to be regulated by both developmental and environmental signals. Levels of mRNA for sEH were higher in meristematic tissue than in mature leaves. This mRNA was also observed to accumulate on wounding and application of exogenous methyl jasmonate.

Binding of uropathogenic Escherichia coli R45 to glycolipids extracted from vaginal epithelial cells is dependent on histo-blood group secretor status

Women with a history of recurrent Escherichia coli urinary tract infections (UTIs) are two to three times more likely to be nonsecretors of histo-blood group antigens than are women without such a history. Further, uroepithelial cells from women who are nonsecretors show enhanced adherence of uropathogenic E. coli compared with cells from secretors. To investigate the hypothesis that nonsecretors express unique receptors for uropathogenic E. coli related to their genetic background, we extracted glycosphingolipids (GSLs) from vaginal epithelial cells collected from nonsecretors and secretors and used an assay in which radiolabeled uropathogenic E. coli were bound to these GSLs separated on TLC plates. An E. coli strain (R45) expressing both P and F adhesins, which was isolated from one of these patients' UTIs, was metabolically labeled with 35S for the TLC binding assay. The radiolabeled E. coli R45 bound to two extended globo-series GSLs, sialosyl gal-globoside (SGG) and disialosyl gal-globoside (DSGG), found in the GSL extracts from nonsecretors but not from secretors. The identity of SGG in the nonsecretor GSL extracts was confirmed in radioimmunoassays using an mAb to SGG and in immunofluorescence assays with this mAb and native vaginal epithelial cells. We show that SGG and DSGG are selectively expressed by epithelial cells of nonsecretors, presumably as a result of sialylation of the gal-globoside precursor glycolipid, which in secretors is fucosylated and processed to ABH antigens. The presence of SGG and DSGG may account for the increased binding of E. coli to uroepithelial cells from nonsecretors and for their increased susceptibility to recurrent UTI.

Partial amino acid sequence of potato solanidine UDP-glucose glucosyltransferase purified by new anion-exchange and size exclusion media

Solanidine UDP-glucose glucosyltransferase (SGT) is involved in the biosynthesis of steroidal glycoalkaloids in potatoes. This enzyme is present at an extremely low level, is inherently unstable, and copurifies with the major storage protein patatin during isolation. We describe an improved method for isolating SGT from greening potato peel using two new chromatographic supports, Macro-Prep 50 Q anion-exchange and Superdex 75HR size exclusion media, under medium-pressure conditions at room temperature. The enzyme preparation was further resolved by SDS-PAGE and the proteins transferred to PVDF membrane (Immobilon-P). Two protein bands corresponding to active forms of SGT (36 and 37 kDa) were excised and cleaved with cyanogen bromide in trifluoroacetic acid. The resultant peptide mixtures were then separated by Tricine-SDS-PAGE and transferred to a PVDF membrane (Pro-Blott). The two major peptide bands observed in both digests (17 and 19 kDa) were sequenced. Identical N-terminal sequences were obtained from the 19-kDa peptides from both digests.

Urovirulence determinants in Escherichia coli isolates causing first-episode and recurrent cystitis in women

To assess the prevalence of urovirulence determinants among Escherichia coli isolates from women with acute uncomplicated cystitis, 121 isolates from 87 women with first-episode or recurrent cystitis and 156 fecal isolates from 52 women without recent urinary tract infection were tested using DNA probes for P fimbriae, hemolysin, aerobactin, and diffuse adhesin and for expression of hemolysin and P and F adhesins. P fimbrial genotype (P = .002), hemolysin phenotype (P = .007), and the diffuse adhesin determinant (P = .03), but not aerobactin, were found more frequently in E. coli from women with acute cystitis, and expression of the F adhesin (41%) was more common than the P adhesin (24%; P = .001). E. coli isolates that caused cystitis in women using diaphragms had fewer virulence determinants than those from nonusers (P = .04), suggesting that diaphragm use may allow infection with less virulent E. coli.

The Tn3 beta-lactamase gene acts as a hotspot for meiotic recombination in yeast

Although genetic distances are often assumed to be proportional to physical distances, chromosomal regions with unusually high (hotspots) or low (coldspots) levels of meiotic recombination have been described in a number of genetic systems. In general, the DNA sequences responsible for these effects have not been determined. We report that the 5' region of the beta-lactamase (ampR) gene of the bacterial transposon Tn3 is a hotspot for meiotic recombination when inserted into the chromosomes of the yeast Saccharomyces cerevisiae. When these sequences are homozygous, both crossing over and gene conversion are locally stimulated. The 5' end of the beta-lactamase gene is about 100-fold "hotter" for crossovers than an average yeast DNA sequence.

Postcoital antimicrobial prophylaxis for recurrent urinary tract infection. A randomized, double-blind, placebo-controlled trial

We conducted a randomized, double-blind, placebo-controlled study to determine the efficacy of postcoital antibiotic prophylaxis in healthy young women prone to recurrent urinary tract infections. Sixteen patients were randomized to receive postcoital administration of a combination product of trimethoprim and sulfamethoxazole, while 11 received postcoital placebo. The treatment groups were similar with respect to age, parity, diaphragm use, history of lifetime urinary tract infections, frequency of intercourse, and number of lifetime sexual partners. In over 6 months of observation, postcoital administration of trimethoprim-sulfamethoxazole was highly effective in preventing recurrent urinary tract infections. Nine of 11 patients who took the placebo developed urinary tract infections (infection rate, 3.6 per patient-year), compared with only two of 16 patients who received postcoital trimethoprim-sulfamethoxazole (infection rate, 0.3 per patient-year). Postcoital administration of trimethoprim-sulfamethoxazole was effective in patients with both low (two or fewer times per week) and high (three or more times per week) intercourse frequencies. Side effects were few and compliance was excellent. We conclude that postcoital trimethoprim-sulfamethoxazole is a safe, effective, and inexpensive approach to management of recurrent urinary tract infections in young women.

Curtatoxins. Neurotoxic insecticidal polypeptides isolated from the funnel-web spider Hololena curta

Three polypeptide neurotoxins (curtatoxins) were isolated from the venom of the spider Hololena curta by reverse-phase high performance liquid chromatography, gel permeation, and ion-exchange chromatography. The purified toxins induced an immediate paralysis in the cricket Acheta domestica that resulted in desiccation and death of the insect within 24-48 h (LD50 congruent to 4-20 micrograms/g); this toxic effect is consistent with irreversible presynaptic neuromuscular blockade. Curtatoxins are a class of sequence-related, cysteine-rich, carboxyl-terminal amidated polypeptides of 36 to 38 amino acid residues. The cysteine residues are conserved at identical sequence positions among these polypeptides and form 4 intramolecular disulfide bonds. Hydropathy calculations show that the toxins have an internal hydrophobic region flanked by hydrophilic and oppositely charged amino- and carboxyl-terminal ends. By analogy to other cysteine-rich arthropod venom proteins, the folded structure of the curtatoxins is likely important for their target specificity and mode of action at the neuromuscular junction.

A rapid purification of L-glutamic acid decarboxylase from the brain of the locust Schistocerca gregaria

L-Glutamic acid decarboxylase (GAD; EC 4.1.1.15) was purified to apparent homogeneity from the brain of the locust Schistocerca gregaria using a combination of chromatofocusing (Mono P) and gel filtration (Superose 12) media. The homogeneity of the enzyme preparation was established by native polyacrylamide gel electrophoresis (PAGE) with silver staining. The molecular weight of the purified enzyme was estimated from native gradient gel electrophoresis and gel filtration chromatography to be 97,000 +/- 4,000 and 93,000 +/- 5,000, respectively. When analysed by sodium dodecyl sulphate-PAGE, the enzyme was found to be composed of two distinct subunits of Mr 51,000 +/- 1,000 and 44,000 +/- 1,500. Tryptic peptide maps of iodinated preparations of these two subunits showed considerable homology, suggesting that the native enzyme is a dimer of closely related subunits. The purified enzyme had a pH optimum of 7.0-7.4 in 100 mM potassium phosphate buffer and an apparent Km for glutamate of 5.0 mM. The enzyme was strongly inhibited by the carbonyl-trapping reagent aminooxyacetic acid with an I50 value of 0.2 microM.

Recombination in yeast and the recombinant DNA technology

The development of methods to isolate eukaryotic genes, alter these genes in vitro and reintroduce them into the cell has had a major impact on the study of recombination in the yeast Saccharomyces cerevisiae. In this paper we discuss how recombinant DNA techniques have been employed in the study of recombination in yeast and the results that have been obtained in these studies.

Further characterisation of the [35S]-TBPS binding site of the GABA receptor complex in locust (Schistocerca gregaria) ganglia membranes

1. Using homogenates of supraoesophageal ganglia from locust we observed specific binding of [35S]-TBPS which was linear with protein concentration up to 7 mg/ml, showed a pH optimum at pH 9.0 and was linear with NaCl concentration up to 350 mM. 2. Kinetic analysis of the binding showed positive cooperativity as a result of changes in on and off-rates with occupation of the binding site by the ligand. The apparent KD = 417 nM and Bmax = 1083 fmol/mg of membrane protein were calculated using a computer program for dose-response curve fitting. 3. The binding was enhanced by GABA, pentobarbital and benzodiazepines. Picrotoxinin had no effect on the binding at 0.1 mM. Only the cage convulsants TBPS and IBP were able to displace the binding. 4. Whilst the characteristics of the binding are similar to those reported for house fly thorax and abdomen preparations they are significantly different from those reported for house fly head, cockroach nerve cord and rat brain.