An innovative approach of risk planning for space programs

According to the current rule-based risk management approach at the National Aeronautics and Space Administration (NASA), the effort is directed to contain all identified risks of a program. The identification of hazards and mitigation effort proceeds along with the development of the system hardware, till all the tradable resources for a program is exhausted. In this process, no conscious effort is made to evaluate risks and associated cost, and the final design is likely to have undesirable residual risks. This approach also results in allocating a significant amount of resources to gain only marginal mitigation of hazard and leave some undesirable hazards in the system due to the budget limitation. The approach in the proposed knowledge-based risk planning system makes a conscious attempt to trade risk with other resources, e.g., schedule, cost, reliability, performance, and others in a judicious and cost-effective way. A knowledge of the feasible option sets requiring high incremental cost for a marginal gain in hazard reduction helps the management to make decision for residual risk that falls within an acceptable range for an option set.

Self-assessed health-related quality of life in men who have completed radiotherapy for prostate cancer: instrument validation and its relation to patient-assessed bother of symptoms

The purpose of this study was to develop a psychometrically reliable and valid questionnaire to assess the disease-specific dimensions of health-related quality of life (HRQOL) in the urinary function (UF), bowel function (BF), and sexual function (SF) domains of prostate cancer (PCa) patients treated with radiation therapy. Patients were given a six-page questionnaire using Likert-type questions assessing three HRQOL dimensions during their follow-up visits after completing radiotherapy. Scales created from an earlier study were utilized and tested for reliability and validity. In addition, we assessed the relationship between these dimensions and the degree to which a decreased HRQOL increases the degree to which patients feel bothered about their symptoms. There are two scales within each dimension: BF, Urgency and Daily Living; UF, Urgency and Weakness of Stream; SF, Interest/Satisfaction and Impotence. Internal-consistency reliability coefficients (Cronbach's alpha) for the proposed scales range from 0.48 to 0.92, and all item-scale correlations and divergence correlations validate the use of the scales, ranging from 0.49 to 0.89. The validity of these scales is also confirmed by the rising median scores with rising reported levels of patient-perceived "bother." The different dimensions have differing quantitative influences on patients. We have developed a prostate-specific HRQOL instrument that is an adequate and suitable tool for measuring HRQOL along three distinct dimensions for patients who have completed radiotherapy for PCa. Psychometric standards for reliability and validity were met for the proposed scales. Moreover, positive correlations were found between these dimensions and how bothered patients were by their symptoms, suggesting important relationships that should be followed in PCa patients after radiotherapy. Certain scales have strong influences on patient-perceived "bothersomeness" of symptoms, such as loss of control of BF, urgency of BF, urgency of urination, and level of interest/satisfaction in sex. Compared to our earlier study on patients being treated with radiotherapy for PCa, this study produced very similar results. With some modification, the same questionnaire could be used for both groups of patients. Int. J. Cancer (Radiat. Oncol. Invest.) 90, 163-172 (2000).

Comparison of seven and fourteen days of lansoprazole, clarithromycin, and amoxicillin therapy for eradication of Helicobacter pylori: a report from India

BACKGROUND

In developed countries, a 1-week regimen of combined proton pump inhibitors and two antibiotics is considered adequate for Helicobacter pylori eradication. However, there is a paucity of reports from developing countries on treatment duration of less than 14 days. We compared efficacy of 7 and 14 days of lansoprazole (L), clarithromycin (C), and amoxicillin (A) combinations for eradication of H. pylori.

PATIENTS AND METHODS

Forty-six consecutive patients who presented with upper gastrointestinal symptoms and tested positive for H. pylori infection were included in the study. In every patient, after performance of upper gastrointestinal endoscopy, antral biopsies were obtained. H. pylori infection was diagnosed by positive rapid urease test and identification of organisms on antral histology. Patients were randomly selected to receive lansoprazole, 30 mg once daily, plus clarithromycin, 250 mg twice daily, plus amoxicillin, 500 mg three times daily for 2 weeks (group 1; n = 24; age, 36 +/- 12 years; 18 men) or 1 week (group 2; n = 22; age, 45 +/- 15 years; 12 men). One month after completion of treatment, repeat upper gastrointestinal endoscopy was performed. H. pylori eradication was defined as absence of organism on histopathological examination of both antrum and body of stomach and negative rapid urease test.

RESULTS

Eradication rate was higher in group 1 (23 of 24; 96%) as compared to group 2 (12 of 22; 54%; p <.05). One patient in group 1 had diarrhea, and one patient in group two had skin rash and itching.

CONCLUSIONS

Fourteen-day therapy with lansoprazole, clarithromycin, and amoxicillin is highly effective in eradication of H. pylori. Reducing duration of therapy to 7 days significantly lowers eradication rates.

Evaluation of E test for susceptibility testing of Mycobacterium tuberculosis to primary anti tubercular drugs

BACKGROUND & OBJECTIVES

Antimicrobial susceptibility tests for tuberculosis take weeks and delayed therapy can lead to an increase in disease incidence. The E test is a new concept for minimum inhibitory concentrations (MIC) determinations for antimicrobial agents that is based on a predefined antibiotic gradient on a plastic strip calibrated with a continuous logarithmic MIC scale covering 15 two-fold dilutions. The present study was undertaken to evaluate E test strips for susceptibility testing of Mycobacterium tuberculosis.

METHODS

Twenty five clinical isolates of M. tuberculosis were tested for the four first line antitubercular drugs by E test and were compared with standard proportion method. The inoculum turbidity was adjusted to McFarland 3.0 standard and agar plates (Middle brook 7H11 agar) were inoculated and preincubated (37 degrees C in 7-10% CO2) for 24 h after which time, the E test strips were placed on the agar surface which were incubated under same conditions. The MIC was interpreted as the point at which the ellipse intersected the 'E test' strip as described in E test technical guide.

RESULTS

Of the 25 strains, susceptibility as determined by both methods for isoniazid (INH), rifampin, ethambutol and streptomycin was found in 22 (88%), 20 (80%), 24 (96%) and 18 (72%) strains respectively. Agreement between E test and proportion method was 96 per cent for INH, 92 per cent for rifampin and 100 per cent for ethambutol and streptomycin each. However, sensitivity could be predicted after 7-10 days by E test and exact MIC could also be determined.

INTERPRETATION & CONCLUSIONS

E test method was found to be rapid, accurate, reliable and easy to perform. It can be employed for routine susceptibility testing for antitubercular drugs.

Helicobacter pylori infection in chronic smokers with non ulcer dyspepsia

BACKGROUND/AIMS

Both H. pylori infection and smoking are risk factors for acid peptic disorders. There is paucity of data on relationship between smoking and H. pylori infection. Therefore, we studied prevalence of H. pylori infection in smokers with non-ulcer dyspepsia (NUD).

PATIENTS AND METHODS

30 smokers with NUD (age 29.5 +/- 1.2 years; all men) and 30 non-smokers with NUD (age 29.2 +/- 1.6 years; all men) were included. None was on antiulcer drugs or antibiotics for more than 2 weeks. Upper gastrointestinal endoscopy was performed and antral biopsies obtained were subjected to rapid urease test, Gram's staining, culture and histopathology. Patient was considered H. pylori positive, if culture was positive or combination of histopathology plus rapid urease test or Gram's staining plus rapid urease test was positive.

RESULTS

24 of 30 (80%) smokers and 13 of 30 (43%) non smokers were positive for H. pylori infection (p < 0.001). There was no significant difference in the positivity of H. pylori in light (78%), moderate (81%) and heavy smokers (80%). All the 37 patients who were positive for H. pylori had histological gastritis compared to 65% in H. pylori negative patients. However there was no difference in presence of histological gastritis among H. pylori negative smokers (33%) and non smokers (70%; p = NS).

CONCLUSIONS

H. pylori infection is more common in smokers with NUD than in non-smokers. However duration and amount of smoking has no relationship with H. pylori positivity.

Efficacy, safety and immunogenicity of heptavalent pneumococcal conjugate vaccine in children. Northern California Kaiser Permanente Vaccine Study Center Group

OBJECTIVE

To determine the efficacy, safety and immunogenicity of the heptavalent CRM197 pneumococcal conjugate vaccine against invasive disease caused by vaccine serotypes and to determine the effectiveness of this vaccine against clinical episodes of otitis media.

METHODS

The Wyeth Lederle Heptavalent CRM197 (PCV) was given to infants at 2, 4, 6 and 12 to 15 months of age in a double blind trial; 37,868 children were randomly assigned 1:1 to receive either the pneumococcal conjugate vaccine or meningococcus type C CRM197 conjugate. The primary study outcome was invasive disease caused by vaccine serotype. Other outcomes included overall impact on invasive disease regardless of serotype, effectiveness against clinical otitis media visits and episodes, impact against frequent and severe otitis media and ventilatory tube placement. In addition the serotype-specific efficacy against otitis media was estimated in an analysis of spontaneously draining ears.

RESULTS

In the interim analysis in August, 1998, 17 of the 17 cases of invasive disease caused by vaccine serotype in fully vaccinated children and 5 of 5 of partially vaccinated cases occurred in the control group for a vaccine efficacy of 100%. Blinded case ascertainment was continued until April, 1999. As of that time 40 fully vaccinated cases of invasive disease caused by vaccine serotype had been identified, all but 1 in controls for an efficacy of 97.4% (95% confidence interval, 82.7 to 99.9%), and 52 cases, all but 3 in controls in the intent-to-treat analysis for an efficacy of 93.9% (95% confidence interval, 79.6 to 98.5%). There was no evidence of any increase of disease caused by nonvaccine serotypes. Efficacy for otitis media against visits, episodes, frequent otitis and ventilatory tube placement was 8.9, 7.0, 9.3 and 20.1% with P < 0.04 for all. In the analysis of spontaneously draining ears, serotype-specific effectiveness was 66.7%.

CONCLUSION

This heptavalent pneumococcal conjugate appears to be highly effective in preventing invasive disease in young children and to have a significant impact on otitis media.

Enteropathogenic Escherichia coli isolates in paediatric diarrhoea

Enteropathogenic Escherichia coli (EPEC) are known to cause infantile enteritis. We studied the prevalence of EPEC in paediatric patients with acute and persistent diarrhoea. A total of 56 stool samples from paediatric patients were studied. There were 28 significant bacterial isolates. Of these 21 were untypable E. coli, 5 were typable E. coli, four of which belonged to members considered to be enteropathogenic. Non E. coli isolates grown in pure culture were one each of Pseudomonas aeruginosa and Citrobacter freundi. The study reveals the definitive role of EPEC in childhood diarrhoea at all age groups and emphasizes the need for characterisation of all significant E. coli isolates in this age group.

Pleural involvement by Salmonella senftenberg: a report of two cases

Non-typhoidal serovars of salmonella are an unusual cause of pleuropulmonary infections. We report two patients with empyema caused by Salmonella senftenberg. One patient had associated diabetes and gall bladder carcinoma, and infection was acquired in hospital. Both patients responded well to parenteral antibiotics.

Postmarketing evaluation of the safety and effectiveness of varicella vaccine

BACKGROUND

The Oka strain of live attenuated varicella virus was licensed for use in healthy children in the United States in March, 1995. We report a postmarketing evaluation of the short term safety of this vaccine within Kaiser Permanente.

METHODS

After licensure varicella vaccination was introduced into the preventive care program of the Northern California Kaiser Permanente Medical Care Program. Potential adverse events after vaccination with varicella vaccine were identified from automated clinical databases of hospitalizations, emergency room visits and clinic visits. Deaths were identified from automated clinical databases at Kaiser as well as from the State death records for California. To evaluate safety, rates of diagnosis-specific events in the risk periods were compared with the rates of such diagnosis-specific events in two self control and one historical control period.

RESULTS

During the study period of April 1, 1995, to December 31, 1996, a total of 89753 adults and children received varicella vaccine. A total of 3200 relative risks were calculated, and of these 5 hospital diagnostic categories, 9 emergency visit diagnostic categories and 30 outpatient diagnostic categories demonstrated at least 1 relative risk with a P value of <0.05 in 1 or more age groups and in comparisons with 1 control period or more. The p value for these tests was not adjusted for multiple comparisons. Of these categories 14 demonstrated an increased risk either in more than 1 age group or against more than 1 comparison group. These categories included elective procedures, febrile seizure, febrile illness, well child, acute gastroenteritis, varicella, congenital anomaly, "rule out sepsis," trauma, viral syndrome, apnea, back pain, congenital valvular heart disease and vision evaluation for glasses. Of these the outcomes of elective procedure, congenital anomaly, congenital valvular heart disease, well child and vision evaluation for glasses were judged not to have a biologically plausible association with vaccination. A second diagnostic grouping included febrile illness, viral illness, febrile seizure and "rule out sepsis." In an analysis of these events which adjusted for the concomitant administration of M-M-R(II) vaccine, none of the associations was statistically associated with receipt of varicella vaccine. The diagnostic category of "rule out sepsis" still had a relative risk of 1.95 with P = 0.02. None of the children in the "rule out sepsis" category had positive bacteriologic cultures from any other normally sterile site. Because of the large number of gastroenteritis cases, we reviewed a random sample of 100 exposed and 100 unexposed cases. From this review no consistent time association or clustering of any of these events was seen in the exposed follow-up time interval. Only gastroenteritis and negative evaluations for sepsis were thought to be possibly associated with receipt of varicella vaccine. Although there was a statistically significant increased risk over the entire 30 day-period, there was no clustering of these events within the 30-day window.

CONCLUSION

In this study population of 89753 children and adults, the varicella vaccine (Oka strain, Merck) appeared to have a favorable safety profile. In addition rates of varicella-like rash and of breakthrough cases were both low and consistent with the rates observed in prelicensure studies.

Racial differences in prostate-specific antigen levels and prostate-specific antigen densities in patients with prostate cancer

To compare serum prostate-specific antigen (PSA) levels and PSA density (PSAD) among African American (AA), white, and Hispanic men with prostate cancer (PC) seen in an urban, equal-access urology clinic. Between January 1988 and January 1993, 1,105 men were screened for PC at Cook County Hospital in Chicago, Illinois. A total of 529 men underwent transrectal ultrasound-guided prostate gland biopsies for abnormal digital rectal examination, suspect transrectal ultrasound, elevated PSA, or any combination of these abnormalities. PC was found in 246 patients (204 AAs, 22 whites, and 20 Hispanics). We analyzed the differences in PSA and PSAD among the three racial groups using univariate and multivariate analyses adjusting for race, age, clinical stage, and grade. AAs have a higher mean serum PSA levels (21.56 ng/ml) than whites (mean PSA of 10.96 ng/ml) and Hispanics (mean PSA of 8.25 ng/ml) (p = 0.04). The mean PSAD also was higher in AAs than in the other two groups (0.68 versus 0.34 for whites and 0.31 for Hispanics, p = 0.05). On a multivariate analysis, the PC stage and grade were overwhelmingly significant, whereas the race and age lost their statistical significance. AAs have higher serum PSA and PSAD than whites or Hispanics in an equal-access healthcare environment. Race is a significant factor in determining PSA and PSAD on univariate but not on multivariate analysis. Preliminary studies suggest that these differences are due to sociological, not biologic causes. These findings warrant a large, prospective study to investigate the extent and the causes of the racial differences in PSA and PSAD.

Phospholipaise A2 and arachidonic acid-mediated mechanism of neuroexocytosis: a possible target of botidinum neurotoxin A other then SNAP-25

The vesicular neuroexocytosis process consists of two important steps: fusion of transmitter-loaded vesicles at release sites on the presynaptic nerve terminal membrane; followed by the release of transmitter molecules into the synaptic cleft. We previously reported that in nerve growth factor (NGF)-differentiated PC12 cells, arachidonic acid (AA) release is associated with acetylcholine (ACh) release, botulinum neurotoxin A (BoNT/A) inhibits both processes and AA itself or a phospholipase A(2) (PLA(2)) activator can cause ACh release in BoNT/A-poisoned cells in which SNAP-25 has supposedly been hydrolyzed. In the present study, we examined the roles of two endogenous intraterminal components in neuroexocytosis: the membrane fusogenic agent AA; and the vesicle fusion protein SNAP-25. A PLA(2) activator, mastoparan, was used to induce the release of AA and ACh from NGF-differentiated PC12 cells. Release depended upon the mastoparan concentration, as well as Ca(2+) influx via the neuronal-type voltage-sensitive Ca(2+) channels. Release of ACh followed a rise in intracellular free Ca(2+) concentration; the increased Ca(2+) activated PLA(2) and, thereby, increased the AA level. Scanning and transmission electron microscopy confirmed that mastoparan-induced ACh and AA release were not due to simple diffusion through damaged plasma membranes. Treatment of PC12 cells with appropriate antisense oligonucleotides blocked SNAP-25 expression, as judged by Western blot protein analysis with a specific monoclonal antibody. Despite apparent elimination of SNAP-25, treatment of differentiated PC12 cells with mastoparan and high (80 mM) K(+) induced ACh exocytosis. The results support the conclusion that PLA(2) and AA have important roles in neuroexocytosis that are independent of SNAP-25. Both PLA(2) and AA have been shown to be involved in actin cytoskeletal organization related to vesicle fusion and exocytosis. This mechanism may be an alternative target of BoNT/A other than SNAP-25.

Prevalence of Helicobacter pylori infection in patients with reflux oesophagitis

In this prospective study 30 patients of reflux esophagitis were studied to detect if there was any association between presence of esophagitis and H. pylori infection. 30 patients of non-ulcer dyspepsia acted as controls. In both the groups esophageal and antral biopsies were studied for the presence of H. pylori infection. None of the esophageal biopsies showed H. pylori infection in either group. H. pylori positivity was similar in the antrum of the patients with esophagitis (20 out of 30) and non ulcer dyspepsia (19 out of 30) (p > 0.05). There was no significant association between presence of H. pylori infection in antrum and severity of esophagitis (p > 0.05). In conclusion, this study has shown that H. pylori did not colonise esophagus in patients of esophagitis or patients of non-ulcer dyspepsia. There was no significant association between H. pylori colonization in the antrum and esophagitis and the grade of esophagitis with H. pylori infection.

Inhibition of allergic inflammation in a murine model of asthma by expression of a dominant-negative mutant of GATA-3

The cytokines IL-4, IL-5, and IL-13, secreted by Th2 cells, have distinct functions in the pathogenesis of asthma. We have previously shown that the transcription factor GATA-3 is expressed in Th2 but not Th1 cells. However, it was unclear whether GATA-3 controls the expression of all Th2 cytokines. Expression of a dominant-negative mutant of GATA-3 in mice in a T cell-specific fashion led to a reduction in the levels of all the Th2 cytokines IL-4, IL-5, and IL-13. Airway eosinophilia, mucus production, and IgE synthesis, all key features of asthma, were severely attenuated in the transgenic mice. Thus, targeting GATA-3 activity alone is sufficient to blunt Th2 responses in vivo, thereby establishing GATA-3 as a potential therapeutic target in the treatment of asthma and allergic diseases.

Safety and immunogenicity of heptavalent pneumococcal CRM197 conjugate vaccine in infants and toddlers

OBJECTIVES

The objectives of this study were (1) to determine the safety and immunogenicity of heptavalent pneumococcal CRM197 conjugate (PNCRM7) vaccine in infants and (2) to determine the effect of concurrent hepatitis B immunization during the primary series and the effect of concurrent diphtheria and tetanus toxoid and acellular pertussis [DTaP (ACEL-IMUNE)] and conjugate CRM197 Haemophilus influenzae type b [HbOC (HibTITER) immunization at time of the booster dose on the safety and immunogenicity of PNCRM7and these other concurrently administered vaccines.

METHODS

This was a randomized double-blinded study in 302 healthy infants in the Northern California Kaiser Permanente (NCKP) Health Plan. Infants received either PNCRM7 vaccine or meningococcal group C conjugate vaccine as a control at 2, 4 and 6 months of age and a booster at 12 to 15 months of age. Study design permitted the evaluation of immunology and safety of concurrent administration of routine vaccines. Antibody titers were determined on blood samples drawn before and 1 month after the primary series and the booster dose.

RESULTS

After the third dose of PNCRM7 geometric mean concentrations (GMCs) ranged from 1.01 for serotype 9V to 3.72 microg/ml for serotype 14. More than 90% of all subjects had a post-third dose titer of > or =0.15 microg/ml for all serotypes, and the percentage of infants with a post-third dose titer of > or =1.0 microg/ml ranged from 51% for type 9V to 89% for type 14. After the PNCRM7 booster dose, the GMCs of all seven serotypes increased significantly over both post-Dose 3 and pre-Dose 4 antibody levels. In the primary series there were no significant differences in GMCs of pneumococcal antibodies between the subjects given PN-CRM7 alone or concurrently with hepatitis B vaccine. At the toddler dose concurrent administration of PNCRM7 and DTaP and HbOC resulted in a near conventional threshold for statistical significance of a post-Dose 4 GMC for serotype 23F [alone 6.75 mirog/ml vs. concurrent 4.11 microg/ml (P = 0.057)] as well as significantly lower antibody GMCs for H. influenza polyribosylribitol phosphate, diphtheria toxoid, pertussis toxin and filamentous hemagglutinin. For all antigens there were no differences between study groups in defined antibody titers that are considered protective.

CONCLUSION

We conclude that PNCRM7 vaccine was safe and immunogenic. When this vaccine was administered concurrently at the booster dose with DTaP and HbOC vaccines, lower antibody titers were noted for some of the antigens when compared with the antibody response when PNCRM7 was given separately. Because the GMCs of the booster responses were all generally high and all subjects achieved similar percentages above predefined antibody titers, these differences are probably not clinically significant.

Potency preservation following conformal radiotherapy for localized prostate cancer: impact of neoadjuvant androgen blockade, treatment technique, and patient-related factors

PURPOSE

Impotence is a familiar sequela of both definitive external-beam radiotherapy (EBRT) and radical prostatectomy for localized prostate cancer. Among surgical options, nerve-sparing radical prostatectomy (NSRP) offers the highest potency preservation rate of 70%. We report the change in potency over time in an EBRT-treated population, determine the significantly predisposing health and treatment factors affecting post-EBRT potency, and compare age- and stage-matched potency rates with those of NSRP-treated patients.

PATIENTS AND METHODS

Our results are from a retrospective study of 287 patients diagnosed with prostate cancer in clinical stages A to C and treated with conformal techniques to 6200 to 7380 cGy. Information regarding preradiotherapy potency, medical and surgical history, neoadjuvant antiandrogen use, and post-EBRT potency was documented for each patient. The median follow-up time was 34 months.

RESULTS

At months 1, 20, 40, and 60, actuarial potency rates were 96%, 75%, 59%, and 53%, respectively. Factors identified as significant predictors of post-EBRT impotence include pre-EBRT partial potency, diabetes, coronary artery disease, and anti-androgen medication usage. Among treatment factors, a trend toward potency preservation was noted for the six-field versus the four-field technique. Finally, age- and stage-matched comparisons of potency rates for our population and NSRP-treated patients were performed. For patients older than 70 years, 60.9% of EBRT patients and 32.9% of NSRP patients remained potent after treatment. Overall, EBRT patient potency preservation was 71.3%, versus 66.2% for NSRP patients.

DISCUSSION

Pre-EBRT partial potency, diabetes, coronary artery disease, and anti-androgen medication usage are significant predispositions to impotence in EBRT-treated prostate cancer patients. In comparing EBRT with NSRP for various age and stage groups, EBRT offers notably higher potency preservation rates than NSRP for patients older than 70 years.

Compound heterozygosity for the Achondroplasia-hypochondroplasia FGFR3 mutations: prenatal diagnosis and postnatal outcome

We report on a male newborn infant, a compound carrier of heterozygous mutations in the FGFR3 gene causing achondroplasia and hypochondroplasia. The mother has achondroplasia and carries the common G1138 (G380R) mutation in the FGFR3 gene; the father has hypochondroplasia due to the C1620A (N540K) mutation in the same gene. The fetus was found to carry both mutations diagnosed prenatally by amniocentesis at 17.6 weeks of gestation, following maternal serum screening which showed an increased risk for Down syndrome (1:337). Detailed fetal ultrasound studies showed a large head, short limbs, and a small chest at 22 weeks of gestation. The changes were more severe than those of either achondroplasia or hypochondroplasia. The patient was born by cesarean section at 38 weeks of gestation and had rhizomelic shortness of the upper and lower limbs with excess skin folds, large head, enlarged fontanelles, frontal bossing, lumbar gibbus, trident position of the fingers, and a narrow chest with a horizontal line of demarcation at the narrowest area of the chest. Skeletal radiographs showed shortness of the long bones and flare of metaphyses. He had respiratory difficulties and was treated with nasal prongs. Seizures developed on day 2 of life and recurred on day 9 and responded to treatment with phenobarbital. Brain computed tomographic scan showed possible grey matter heterotopia, partial agenesis of the corpus callosum, and cortical dysplasia. To our knowledge, there are only two previously published cases of compound heterozygous achondroplasia-hypochondroplasia patients. The diagnosis was confirmed by DNA mutation analysis of the FGFR3 gene in both cases.

Helicobacter pylori eradication: comparison of three treatment regimens in India

Conventional bismuth-based triple therapy has multiple problems, such as inadequate drug compliance, side effects, and drug resistance. Combination of omeprazole and clarithromycin with or without combination with antibiotics like amoxycillin has been shown to be effective in eradication of Helicobacter pylori. Reports from India are few on the efficacy of clarithromycin-based drug combinations. Therefore, we evaluated efficacy of omeprazole and clarithromycin with or without amoxycillin for treating H. pylori infection. Sixty-four consecutive patients with upper gastrointestinal symptoms and having H. pylori infection were included. In every patient, complete upper gastrointestinal endoscopy was done. H. pylori infection was diagnosed by identification of organism on antral biopsies and positive rapid urease test. Patients were treated with omeprazole 40 mg/day + clarithromycin 250 mg twice daily (group I, n = 22), or omeprazole 40 mg/day + clarithromycin 250 mg twice daily + amoxycillin 500 mg three times daily (group II, n = 20), or bismuth subcitrate 120 mg four times daily + amoxycillin 500 mg three times daily + metronidazole 400 mg three times daily (group III, n = 22) for 2 weeks. H. pylori status was reevaluated 1 month after completion of treatment. One patient in each group stopped drugs due to side effects. Eradication rate was not significantly different in group I (15/22, 68%), group II (14/20, 70%), and group III (13/22, 59%). Of those completing therapy, side effects were observed in three patients in group III (nausea, skin rash, metallic taste), whereas none of the patients in group I and group II had any side effects. Addition of amoxycillin did not appear to improve efficacy of dual omeprazole and clarithromycin therapy and appeared to be no different than bismuth, metronidazole, and amoxycillin triple therapy. Overall, none of regimens was particularly good.

Avalanches in breakdown and fracture processes

We investigate the breakdown of disordered networks under the action of an increasing external-mechanical or electrical-force. We perform a mean-field analysis and estimate scaling exponents for the approach to the instability. By simulating two-dimensional models of electric breakdown and fracture we observe that the breakdown is preceded by avalanche events. The avalanches can be described by scaling laws, and the estimated values of the exponents are consistent with those found in mean-field theory. The breakdown point is characterized by a discontinuity in the macroscopic properties of the material, such as conductivity or elasticity, indicative of a first-order transition. The scaling laws suggest an analogy with the behavior expected in spinodal nucleation.

[14C]-urea breath test to confirm eradication of Helicobacter pylori

BACKGROUND

Treatment for Helicobacter pylori reduces ulcer recurrence. Eradication rates of the organism vary with different drug regimens from 30% to 90%. There is a need to identify patients who have failed treatment. [14C]-Urea breath test (UBT) is non-invasive, sensitive, safe and highly reliable test for diagnosis of H. pylori infection. As there is a paucity of reports on the utility of [14C]-UBT in confirming H. pylori eradication, this study was undertaken.

METHODS

Thirty-eight patients (age 34 +/- 17 years, range 16-84 years, 27 men) with upper gastrointestinal symptoms underwent upper gastrointestinal endoscopy. Baseline H. pylori infection was diagnosed by identification of the organism on antral biopsies and positive rapid urease test (RUT). After 1 month of completion of treatment, repeat RUT and histological examination of antral endoscopic biopsies were performed. Eradication of H. pylori was defined as absence of the organism on histology, and negative RUT. The [14C]-UBT was performed using 185 kBq [14C]-urea dissolved in 300 mL water. Breath samples were collected once before ingestion of [14C]-urea, and subsequently at 5 and 15 min. Results were expressed as 14CO2/mmol CO2 exhaled as per cent of administered urea.

RESULTS

Endoscopy revealed antral gastritis (n = 14), duodenal ulcer (n = 8), duodenitis (n = 2), oesophagitis (n = 1), antral gastritis and duodenal ulcer (n = 3), antral gastritis and duodenitis (n = 7) and normal upper gastrointestinal endoscopy (n = 3). All the 20 patients who were negative for H. pylori on RUT and histology, tested negative for H. pylori on [14C]-UBT. However, of 18 patients shown to have H. pylori infection on RUT and histology, 16 were positive for H. pylori on [14C]-UBT. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of [14C]-UBT were 100, 89, 91, 100 and 95% respectively.

CONCLUSIONS

The [14C]-UBT is a reliable indicator of H. pylori eradication after treatment. It can obviate the need for antral biopsies to confirm eradication of H. pylori after completion of treatment.

Aerobic 4-nitrophenol degradation by microorganisms fixed in a continuously working aerated solid-bed reactor

Studies of microbial purification of a model waste water containing 4-nitrophenol were carried out in a continuously working aerobic solid-bed reactor. The main emphasis was on the dynamic behaviour of the system after a sudden change in cultivation conditions and on the steady state performance of the reactor as a function of the pollution load. A change from ammonium-free to ammonium-containing medium hardly influenced the nitrophenol degradation. The reactor responded differently to an increase in pollutant load, which was brought about by increasing either the 4-nitrophenol content or the flow of the waste water. Up to a load of 270 mg l-1 h-1 the pollutant was stably and almost completely degraded. At a higher load, only a partial 4-nitrophenol degradation took place. A mathematical model was derived to describe the processes that occurred in the reactor. By segregation into two compartments--the aqueous phase and the biofilm--account was taken of the fact that the pollutant is carried into the biofilm by diffusion and is degraded there. The observed relations between the pollutant load, the pollutant concentration in the outlet of the reactor and the reactor performance agreed with the simulated process behaviour. As the model simulation showed, the incomplete pollutant degradation at a higher reactor load was caused by oxygen limitation.

Self-assessed health-related quality of life in men being treated for prostate cancer with radiotherapy: instrument validation and its relation to patient-assessed bother of symptoms

OBJECTIVES

To develop a psychometrically valid and clinically useful questionnaire to assess health-related quality of life (HRQOL) in patients with prostate cancer (PCa) undergoing external beam radiotherapy. The most important factors in three dimensions (bowel function [BF], urinary function [UF], and sexual function [SF]) were identified by patient survey.

METHODS

Three HRQOL dimensions were assessed using Likert-type questions. Responses were analyzed by factor analysis to create HRQOL scales. Reliability and validity of the scales were assessed. Because patients can suffer symptoms yet not report their lives to be affected, the scales were compared with patient-reported bother.

RESULTS

Two scales were identified within each dimension: BF, urgency and daily living; UF, urgency and weakness of stream; and SF, interest/satisfaction and impotence. Cronbach's alpha for the scales ranged from 0.63 to 0.94, and item-scale correlations and item-scale divergence correlations supported scale validity. Rising median scores correlated with rising levels of perceived bother.

CONCLUSIONS

The questionnaire is a suitable tool for assessing HRQOL in three distinct dimensions for patients undergoing radiotherapy for PCa. Six dimensions of HRQOL were found to be related to bother, suggesting important relationships to be monitored for patients. Urgency of bowel movements, urgency of urination, and level of interest/satisfaction in sex correlated most strongly with bother.