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Biomedical subjects

J Wenger

Publications and source records attributed to J Wenger.

At least 19 recordsLinked to original sources
PubMed2001

Vaccines for the developing world: current status and future directions.

Developing country infectious disease problems differ substantially from those in the industrialized world, and a major effort must be made to devote necessary resources to development of vaccines for the bulk of human infectious disease suffering. At the same time, the political will must be mobilized, at international and national levels, to obtain the financial support and backing to provide these vaccines for children. Finally, efforts must be made to take advantage of new technologies now being developed which address many of the logistic and programmatic challenges faced by developing country immunization programme delivery systems.

Child, Preschool↗
PubMed1999

Evaluation of meningococcal meningitis vaccination strategies for the meningitis belt in Africa.

BACKGROUND: Although the meningococcal polysaccharide vaccine has contributed to the control of Group A meningitis in the "meningitis belt" of Africa, recurrent large outbreaks have led to questions regarding vaccination strategy. We evaluated current and hypothetical vaccination strategies for the region. METHODS: A model was formulated to analyze the effectiveness and costs of vaccine campaigns in response to outbreaks based on 7 years of weekly incidence data from Burkina Faso. Additional models analyzed the potential impact and costs of either a 1- or 4-dose routine scheduled delivery of meningococcal polysaccharide vaccine based on data reported to the World Health Organization from 16 countries during 1948 through 1996. Vaccine efficacy, vaccination coverage and economic data from literature reviews provided model assumptions. RESULTS: For Burkina Faso neither 1- nor 4-dose vaccination schedules would prevent >30% of meningitis cases compared with the 42% prevented through an outbreak response program of vaccinating districts, which reach an incidence of 15 per 100000 persons for 2 weeks. For the entire meningitis belt, routine coverage with the 1- or 4-dose schedule meningococcal vaccine would require 4.9 and 19.6 million doses annually, respectively, for an annual net cost of $4.4 to $12.3 million and prevent an average 10300 to 12600 cases (23 to 28%), assuming a long term vaccine efficacy of 50%. In addition an initial "catch-up" campaign costing up to $72 million to vaccinate the population from 1 to 30 years of age would be required before achieving that level of effectiveness. CONCLUSION: Given the relatively poor routine vaccination coverage in this region, current strategies of vaccination campaigns that achieve higher coverage would generally be more effective and less costly than the modeled routine scheduled programs, assuming that campaigns can be rapidly implemented. Until a better vaccine is available, countries in this region would be more efficient in improving the response times to outbreaks, perhaps through improved surveillance, and in bolstering existing vaccination infrastructures rather than embarking on strategies of questionable effectiveness.

Africa↗
PubMed1998

Diphtheria.

Explore the source record for details and available documents.

Child↗
PubMed1996

[Bone mass in celiac patients].

Bone mineral content was measured in the whole body, the spine (L2-L4) and hip by Dual Photonic Absorpciometry (densitometer Norland 2600 Gd-153), in seventeen celiac patients, aged 6 to 12 years, with good adherence to the gluten free diet. The diagnosed was made before 30 months of age in 50% of cases. Average treatment duration was 69.8 +/- 36 months. The randomly selected control group was composed of 48 school age children, of the same age and sex of patients. Total bone mass (TBM) and bone mineral density (BMD) were expressed as Z scores on the basis of normal values established by the authors in Chilean children. Celiac patients had lower TBM and BMD of whole body, than controls (-1.11 +/- 0.94 vs 0.00 +/- 0.85 and -0.59 +/- 0.76 vs 0.06 +/- 0.84, respectively) and at the spine (-0.79 +/- 1.04 vs 0.003 +/- 0.92 and -1.49 +/- 0.99 vs 0.06 +/- 0.87 respectively). A lower TBM was founded at the hip (-0.62 +/- 1.28 vs -0.08 +/- 0.82) without differences in BMD. Celiac patients had a lower bone mass than controls despite early diagnosis and good compliance with the gluten-free diet. These differences could not be atributed entirely to the lower height of celiac patients. These results suggest that celiac patients constitute a risk group for development of osteoporosis later in life. This fact should be taken into consideration in the treatment of this condition.

Bone Density↗
PubMed1995

Meningococcal disease epidemiology and control in New Zealand.

Epidemiology, surveillance and research New Zealand has a high quality surveillance system for meningococcal disease that successfully integrates notification and laboratory data. Since 1991, New Zealand has had elevated incidence rates of meningococcal disease rising to 6.2 per 100,000 population in 1994. This represents a rate that is four times that recorded in 1989/90. Serogroup B infection predominates and international experience suggests that these elevated rates may continue for 5 to 15 years. Rates of meningococcal disease in Maori and Pacific Islands populations were three times higher than in Europeans at 10.0 and 12.3 per 100,000 respectively in 1994. The rates were particularly high for infants with the rate in Maori infants under 1 year reaching 120 per 100,000. The case fatality rate at 5.3% for 1994 would appear to be relatively low by international standards. Case control studies could be used to investigate potentially modifiable primary risk factors for disease. Intensive case review studies to investigate the role of such factors as preadmission antibiotics in reducing severe outcomes may be of benefit. The Ministry of Health or research funding organisations should consider the potential value of such studies in more detail.

Adolescent↗
PubMed1995

Decreased uptake of cyclosporin A by P-glycoprotein (Pgp) expressing CEM leukemic cells and restoration of normal retention by Pgp blockers.

The P-glycoprotein (Pgp) molecules which are expressed on multidrug resistant (MDR) tumor cells can efflux a variety of cytostatics. In both normal and tumoral epitheliums, Pgp molecules are selectively expressed on the apical surface of the epithelial cells. Such a distribution seems to be responsible for the transcellular transport of Pgp substrates, including cyclosporin A (CsA), from the basal to the apical side. Some normal lymphoid cells also express small amounts of Pgp molecules, for as yet unknown functions. Nevertheless, the sensitivity of their mitogen-induced proliferation to cytostatics, including doxorubicin and CsA, could be increased by the Pgp blockers. Using isotopically-labeled CsA and tumoral lymphoid cell lines, we now show a higher CsA retention in Pgp-lacking parental ('Par') cells than in Pgp-expressing MDR cells. The Pgp blockers can restore the CsA retention in the MDR cells to its level in the Par cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1995

Helicobacter pylori-associated gastroduodenal disease in symptomatic Chilean children: diagnostic value of serological assay.

A newly developed enzyme-linked immunosorbent assay (ELISA) IgG serological assay for the diagnosis of Helicobacter pylori infection was used recently in two epidemiological surveys in Chile. To evaluate the diagnostic efficacy of this assay in a local symptomatic pediatric population, we studied 70 school-age patients referred for upper gastrointestinal endoscopy because of complaints suggestive of gastroduodenal disease. Evidence for antral H. pylori infection was sought by three biopsy-related methods: culture, histology, and urease activity. IgG anti-H. pylori serum antibodies were determined by ELISA. Altogether, chronic antral gastritis was found in 55 patients and duodenal ulcers in nine; 11 subjects had normal histology. Sixty (86%) patients had H. pylori in the antrum. This group had significantly higher mean IgG optical density values when compared with the H. pylori-negative group (1.860 versus 0.669; p < 0.001). The sensitivity and specificity of the assay in detecting antral H. pylori were both 90%; the positive predictive value was 98% and the negative, 60%. Accuracy of the assay was superior in predicting the presence or absence of gastroduodenal lesions with a sensitivity of 96%, a specificity of 92%, a positive predictive value of 98%, and a negative predictive value of 86%. We conclude that the diagnostic efficiency of this assay renders it appropriate both to screen for H. pylori-associated gastroduodenal disease in individual patients and to be used in seroepidemiological surveys.

Adolescent↗
PubMed1993

Giant colonic diverticulum: an unusual manifestation of a common disease.

Giant colonic diverticula are an uncommon manifestation of colonic diverticular disease. This report documents another case of this rare entity. The clinical presentation is variable, but abdominal pain and the presence of an abdominal mass are common. Their etiology is uncertain, but they are thought to originate from pulsion diverticula. Abdominal plain films and barium enema are helpful in making the diagnosis. Computerized tomography is useful when the diagnosis is unclear. Surgical resection is recommended to alleviate symptoms and avoid complications.

Aged↗
PubMed1992

Evaluation of a chemiluminescent DNA probe assay for the rapid confirmation of Listeria monocytogenes.

A Listeria monocytogenes-specific, acridinium-ester-labelled DNA probe was evaluated in a chemiluminescent homogeneous protection assay (HPA) for the rapid confirmation of suspect L. monocytogenes colonies from blood agar plates. The HPA uses an acridinium-ester-labelled chemiluminescent DNA probe in a free-solution hybridization format. After the DNA probe hybridized with the target ribosomal RNA, the acridinium label on the unhybridized probe was inactivated by a chemical differential hydrolysis step. Formation of a hybrid between probe and target was detected in a luminometer after the addition of a detection reagent. The assay can be completed in 30 to 45 min and allows for simultaneous processing of several (50-100) samples. The probe showed 100% sensitivity and 100% specificity for L. monocytogenes when evaluated in the HPA against L. monocytogenes, other Listeria species and other Gram-positive bacteria. The lower detection limit of the HPA was between 10(4) and 10(5) cells. In an evaluation with 296 bacterial colonies isolated from food, the HPA colony confirmation showed 100% agreement with conventional biochemical characterization. HPA will be useful for the rapid confirmation of L. monocytogenes isolated from food and clinical specimens.

Acridines↗
PubMed1992

Does hormonal therapy have any benefit for bleeding angiodysplasia?

Sixty-four patients took part in a cohort study measuring the efficacy of daily hormonal therapy in diminishing intestinal bleeding from small bowel angiodysplasia. Thirty patients received 5-10 mg norethynodrel either with mestranol, 0.075-0.15 mg (24 patients) or with conjugated estrogens, 0.625 mg (six patients). The cohort group consisted of 34 patients who either refused hormonal therapy (six patients) or were diagnosed early in our experience, before the resurgence of hormonal therapy (28 patients). Mean follow-up was 15.6 months (range 2-31 months) for the treated group and 13.4 months (range 1-23 months) for the untreated group. In addition, the change in monthly transfusion requirement with therapy was analyzed ("within group" analysis). Fifty percent (15 of 30) of the treated group required no further transfusion during therapy, while 44% (15 of 34) of the untreated group required no further therapy (not significant). During therapy, the mean monthly transfusion requirement of packed red blood cells in the treated group was not significantly different from that found before therapy (1.5 vs. 2.2 units, NS) or from that of the control group (1.5 vs. 1.6 units, NS). The findings do not support the use of hormonal therapy for bleeding from small intestinal angiodysplasia.

Adolescent↗
PubMed1991

Ribosomal DNA fingerprinting of Listeria monocytogenes using a digoxigenin-labeled DNA probe.

A nonisotopic ribosomal DNA fingerprinting technique was developed for the characterization of Listeria monocytogenes. Plasmid pKK3535 (a pBR322-derived plasmid containing rrnB ribosomal RNA operon of Escherichia coli) was labeled with digoxigenin-11-dUTP by random priming and used to probe EcoRI fragments of L. monocytogenes chromosomal DNA on nylon filters. The method was successfully applied to the characterization of two sets of patient and food isolates of L. monocytogenes.

DNA Fingerprinting↗
PubMed1989

[Campylobacter pylori in children and adults subjected to endoscopy, correlation of endoscopic, bacteriologic and histopathologic findings].

Campylobacter pylori has been associated to peptic ulcer and gastritis. We investigated the presence of C pylori in 17 children and 50 adults who needed endoscopy to investigate upper gastrointestinal symptoms. Gram stain, Whartin-Starry stain and the urease test were used to identify the germ; best results were obtained with the Gram stain. C pylori was present in 5.8% of children and 88% of adults, including all patients with peptic ulcer and 36 out of 39 with histologic evidence of gastritis. However, the germ was also found in 79% of patients with a normal mucosa. Our results suggest that C pylori is frequently present in gastric mucosa of children and adults with upper gastrointestinal problems. Further studies are needed to elucidate its possible pathogenic role in gastritis or peptic ulcer.

Adolescent↗