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R Bialek

Publications and source records attributed to R Bialek.

At least 19 recordsLinked to original sources
PubMed2006

[Headache after a stay in the Dominican Republic].

CASE HISTORY: In a 27-year-old female German patient severe headache and wandering paresthesias appeared one week after returning from a holiday in the Dominican Republic. After 3 weeks of ongoing symptoms she was admitted to our hospital with the suspicion of an inflammatory or infectious disease of the central nervous system. Upon admission slight stiffness of the neck, fever (38.2 C) and paresthesias of the right elbow and the right thigh were noticed. LABORATORY FINDINGS: Cerebrospinal fluid (CSF) revealed an eosinophilic pleocytosis. In the acute phase of the disease, antibodies against nematodes were found in CSF, without corresponding antibody-reactivity in serum. In the course levels of nematode antibodies in CSF increased and antibody-reactivity in serum was observed. Thorough investigation for other infectious or inflammatory causes of eosinophilic meningitis revealed no abnormalities. DIAGNOSIS, TREATMENT AND COURSE: Symptoms, onset within the typical incubation period and the eosinophilic meningitis lead to the diagnosis of a suspected Angiostrongyliasis. Successful treatment was achieved with a combination of oral albendazole and corticosteroids given for 4 weeks. CONCLUSION: Infection with larvae of Angiostrongylus cantonensis is one of the main causes of eosinophilic meningitis worldwide. Human infection can occur after ingestion of intermediate hosts or contaminated vegetables. Angiostrongyliasis has been endemic to Southeast Asia and the Pacific Basin and only recently cases from the Caribbean have been described. Headache, paresthesias and the finding of an eosinophilic meningitis in patients returning from tropical or subtropical regions should lead to the suspicion and eventually the treatment of an Angiostrongyliasis.

Adult↗
PubMed2006

Diagnosis of invasive aspergillosis and mucormycosis in immunocompromised patients by seminested PCR assay of tissue samples.

Aspergillosis and mucormycosis are the most common mold infections in patients with hematological malignancies. Infections caused by species of the genus Aspergillus and the order Mucorales require different antifungal treatments depending on the in vitro susceptibility of the causative strain. Cultures from biopsy specimens frequently do not grow fungal pathogens, even from histopathologically proven cases of invasive fungal infection. Two seminested PCR assays were evaluated by amplifying DNA of zygomycetes and Aspergillus spp. from organ biopsies of 21 immunocompromised patients. The PCR assays correctly identified five cases of invasive aspergillosis and six cases of mucormycosis. They showed evidence of double mold infection in two cases. Both assays were negative in five negative controls and in two patients with yeast infections. Sequencing of the PCR products was in accordance with culture results in all culture-positive cases. In six patients without positive cultures but with positive histopathology, sequencing suggested a causative organism. Detection of fungal DNA from biopsy specimens allows rapid identification of the causative organism of invasive aspergillosis and mucormycosis. The use of these PCR assays may allow guided antifungal treatment in patients with invasive mold infections.

Adult↗
PubMed2005

[Parasitic diseases in pediatric cancer patients].

Parasitic infections are rare events in pediatric oncology. Transmission routes and diseases of most parasites do not differ significantly from those seen in otherwise healthy children. However, latent asymptomatic infections with Cryptosporidium spp., Leishmania spp., Strongyloides stercoralis and Toxoplasma gondii might exacerbate during immunosuppression. Screening in asymptomatic patients is often unsuccessful due to the low sensitivity of available assays except in toxoplasmosis. This article provides the recommendations of the Infectious Diseases Working Party of the German Society for Pediatric Infectious Diseases (DGPI) and the German Society for Pediatric Hematology/Oncology (GPOH) for the appropriate diagnostic procedures and antiparasitic treatment immunocompromised patients.

Adolescent↗
PubMed2005

PCR based identification and discrimination of agents of mucormycosis and aspergillosis in paraffin wax embedded tissue.

BACKGROUND: Invasive fungal infections are often diagnosed by histopathology without identification of the causative fungi, which show significantly different antifungal susceptibilities. AIMS: To establish and evaluate a system of two seminested polymerase chain reaction (PCR) assays to identify and discriminate between agents of aspergillosis and mucormycosis in paraffin wax embedded tissue samples. METHODS: DNA of 52 blinded samples from five different centres was extracted and used as a template in two PCR assays targeting the mitochondrial aspergillosis DNA and the 18S ribosomal DNA of zygomycetes. RESULTS: Specific fungal DNA was identified in 27 of 44 samples in accordance with a histopathological diagnosis of zygomycosis or aspergillosis, respectively. Aspergillus fumigatus DNA was amplified from one specimen of zygomycosis (diagnosed by histopathology). In four of 16 PCR negative samples no human DNA was amplified, possibly as a result of the destruction of DNA before paraffin wax embedding. In addition, eight samples from clinically suspected fungal infections (without histopathological proof) were examined. The two PCR assays detected a concomitant infection with Absidia corymbifera and A fumigatus in one, and infections with Rhizopus arrhizus and A fumigatus in another two cases. CONCLUSIONS: The two seminested PCR assays described here can support a histopathological diagnosis of mucormycosis or aspergillosis, and can identify the infective agent, thereby optimising antifungal treatment.

Aspergillosis↗
PubMed2004

Eosinophilic meningomyelitis in toxocariasis: case report and review of the literature.

Toxocariasis is a worldwide-occurring parasitic infection leading to tissue damage in various organs due to wandering Toxocara larvae (visceral larva migrans). More than 40 cases of CNS involvement in children and immunocompetent adults have been documented in detail to date. Here, we present evidence of eosinophilic meningomyelitis in an adult without known risk factors and with positive Toxocara antibody response in CSF, but not in blood. Toxocariasis has to remain among the differential diagnosis in patients with eosinophilic CNS infection even if serological tests in blood are negative. Adult cases seem to be more frequent than previously thought (about 60%).

Adult↗
PubMed2003

Comparison of viability assays for Cryptosporidium parvum oocysts after disinfection.

In order to test various viability assays for Cryptosporidium parvum oocysts were used to infect HCT-8 cells in vitro or baby mice. Infected cells were either stained with fluorescent anti-Cryptosporidium-antibody or lysed and subjected to C. parvum-specific PCR after 48 h. Titrations with infective oocysts were performed and compared to oocysts disinfected with Neopredisan for 2 h at varying concentrations. Caecal smears and histological sections from infected animals were examined in parallel. The number of foci of parasite development in vitro after immunofluorescent staining correlated well with the infection dose. PCR was less quantifiable and the results were not always reproducible, especially when low infection doses were used. Disinfection resulted in a dose-dependent reduction of oocyst infectivity when compared to the controls in all three assays. The infection of cells cultured in vitro with oocysts of C. parvum provides a suitable tool for the estimation of viability after treatment with chemical disinfectants. Immunofluorescence is easy to perform and gives quantitative results, while PCR-based detection of parasite DNA, although possible, requires the use of more sophisticated tools for quantification.

Animals↗
PubMed2002

Rapid PCR-based diagnosis of disseminated histoplasmosis in an AIDS patient.

Disseminated histoplasmosis is an unusual opportunistic infection in patients with advanced HIV infection living outside endemic areas. Diagnosis usually is made on the basis of isolation of Histoplasma capsulatum from clinical specimens or histologic examination. Reported is the case of an HIV-infected Columbian individual in whom the diagnosis of histoplasmosis was established within 24 h of collection of an adequate bronchoalveolar lavage specimen. The diagnosis was made by detection of specific fungal DNA and confirmed by isolation of Histoplasma capsulatum from blood, bone marrow and respiratory specimens 10 days later. The patient recovered under antifungal treatment and remained asymptomatic up to the last follow-up visit 6 months later. The polymerase chain reaction assay might be a powerful and rapid diagnostic tool for the diagnosis of non-European invasive fungal infections and should be further evaluated.

AIDS-Related Opportunistic Infections↗
PubMed2002

Aspergillus antigen and PCR assays in bone marrow transplanted children.

Screening for Aspergillus antigen and DNA has been introduced for the early diagnosis of invasive aspergillosis (IA) in adults, but data in children at risk are scarce. Seventeen 1-108 month-old children were screened for Aspergillus antigenaemia by a commercial assay before and after bone marrow transplantation (BMT). Seventy-one serum samples were examined retrospectively by a novel nested PCR assay. Results of both assays were correlated with clinical, radiological and microbiological findings used for the definition of invasive aspergillosis by the European Organisation for Research and Treatment of Cancer (EORTC). Three cases of probable or possible IA were defined, and in 14 children invasive aspergillosis was ruled out. In 10 children, Aspergillus antigen was detected in at least two consecutive serum samples, a microbiological EORTC criteria of IA. Specific DNA was detected in 8 antigen-positive and 2 antigen-negative sera. A positive predictive value of 20% was calculated for both assays. Hence, a high rate of positive results of antigen Elisa and PCR assays in BMT children are due to transient antigenaemia and fungaemia without clinical relevance. According to our data, prospective studies in well defined pediatric patients are urgently needed to determine the value of serial Aspergillus PCR assays for the early diagnosis of invasive aspergillosis in children at risk.

Antigens, Fungal↗
PubMed2001

Autofluorescence microscopy for the detection of nematode eggs and protozoa, in particular Isospora suis, in swine faeces.

Parasites from swine faeces were examined for autofluorescence. Oocysts of Eimeria polita, E. scabra and Isospora suis, cysts of Balantidium coli and eggs of Oesophagostomum dentatum, Strongyloides ransomi and Trichuris suis (but not those of Ascaris suum) emitted light after excitation with UV light. I. suis oocyst counts in McMaster chambers utilising autofluorescence were compared to those from conventional bright field microscopy. Similarly, faecal smears containing I. suis were examined using the same techniques. Autofluorescence was superior to bright field microscopy in detecting oocysts after flotation and was highly significantly more sensitive when direct smears were examined.

Animals↗
PubMed2001

Diagnosis and monitoring of murine histoplasmosis by a nested PCR assay.

A newly developed nested PCR assay was applied to murine models of histoplasmosis. ICR and BALB/c mice were intravenously infected with Histoplasma capsulatum and sacrificed up to 29 days later. Samples of blood, spleen, and lung homogenates were cultured and examined by the PCR assay. In the ICR mouse model, 265 of 319 organ samples showed concordant results. With 7 samples, the culture was positive and the PCR assay was negative whereas a positive PCR but a negative culture were obtained with 47 samples (P < 0.0001 according to McNemar's test). Organ homogenates and blood samples of either spontaneously cured or treated BALB/c mice were PCR negative. The nested PCR assay performs excellently in the monitoring of spontaneously and treatment-cured murine histoplasmosis. It limits the infection risks of the laboratory staff and might be of diagnostic value for humans.

Animals↗
PubMed2001

Detection of microsporidia in travelers with diarrhea.

We examined stool specimens of 148 returning travelers from an outpatient department for tropical diseases for the appearance of microsporidia using light microscopy and PCR. Intestinal microsporidiosis was diagnosed for five patients by light microscopy and for nine patients by PCR. Some cases were diagnosed only by PCR, indicating that the true prevalence has to be determined by highly sensitive techniques, such as PCR.

Animals↗
PubMed2001

Case report: Nitazoxanide treatment failure in chronic isosporiasis.

We report a 60-year-old immunocompetent patient with chronic biliary isosporiasis who failed to respond to orally administered cotrimoxazole prophylaxis and orally administered treatment with nitazoxanide, a 5-nitrothiazole benzamide compound. Severe malabsorption was regarded as responsible for the subtherapeutic levels of nitazoxanide in plasma and bile, resulting in treatment failure. Intravenously administered cotrimoxazole stopped the shedding of Isospora belli oocysts in bile within 5 days, excluding initially suspected resistance to cotrimoxazole. Patients with malabsorption and cholangitis due to Coccidia such as Isospora belli and Cryptosporidium spp. or due to protozoa that cause microsporidiasis seem to be predisposed to fail to respond to otherwise effective treatment.

Administration, Oral↗
PubMed2000

Taxonomic position of the human intestinal protozoan parasite Isospora belli as based on ribosomal RNA sequences.

The taxonomic positions of Isospora belli and other members of the genus Isospora are controversial. We determined the small-subunit ribosomal RNA of I. belli and used this sequence in combination with other coccidian RNA sequences for analysis of the taxonomic position of I. belli. The phylogenetic trees we obtained provide molecular evidence for three clades within a monophyletic group that represents the suborder Eimeriina. The clade containing I. belli consists of tissue-cyst-forming coccidia (Toxoplasma and Neospora) and members of the genus Isospora (I. ohioensis, I. suis, I. belli). The second clade, representing a sister clade of that containing the Isospora species, contains members of the genus Sarcocystis. The third one consists of members of the family Eimeriidae, including Eimeria and Cyclospora species. This shows that although I. belli as well as other members of the genus Isospora belong to the suborder Eimeriina, the family to which they belong is not Eimeriidae but rather Sarcocystidae. We suggest that the genus Isospora should be removed from the family Eimeriidae and placed into the family Sarcocystidae within the suborder Eimeriina.

Animals↗
PubMed2000

Schistosomiasis in German children.

UNLABELLED: Reports on schistosomiasis in children growing up in Europe are rare despite increased travel activity. We report on eight male and three female German children aged 50 months to 15 years with schistosomiasis. Six children were asymptomatic, whereas two presented with typical signs of Katayama fever. Persisting haematuria, headache with eosinophilia and pyelonephritis were observed in one child each. An exposure was reported for six of the children. Two were examined solely because schistosomiasis was diagnosed in a family member. All had antibodies against schistosomal antigens in at least two of three screening tests. However, schistosomal ova (Schistosoma haematobium) were detected in urine and faecal specimens from only three children. A tumour-like lesion of the bladder was found by ultrasound in only one of the children who also exhibited haematuria. Neither eosinophilia nor elevated IgE levels were constant findings. Six to 12 months after praziquantel treatment, parasitological and ultrasound checks were negative and levels of specific antibodies decreased. However, 2 years later, elevated antibody levels were detected in one girl without evidence of any new exposure. She became antibody-negative 1 year after a second course of treatment. CONCLUSION: In contrast to residents of endemic areas, parasitological and ultrasound examinations seem to be inferior to immunodiagnostics in children from non-endemic areas at temporary risk for schistosomiasis.

Adolescent↗
PubMed2000

Detection of Isospora belli by polymerase chain reaction using primers based on small-subunit ribosomal RNA sequences.

The aim of the present study was to use small-subunit (SSU)-rRNA sequences of Isospora belli to design specific primer pairs and a hybridization probe for the detection of Isospora belli in human samples by PCR and Southern blot hybridization. PCR amplification with the primer pairs produced correct DNA fragments with target DNA from samples of Isospora belli-infected patients and from cloned SSU-rRNA of Isospora belli. The nature of the PCR products was confirmed by Southern blot hybridization. No amplification was seen with template DNA extracted from other parasites. Although Isospora belli infections can be easily diagnosed using light microscopy, molecular-based techniques may prove useful as an additional diagnostic tool.

Animals↗
PubMed2000

A decade of progress in academic/practice linkages.

Almost a decade has passed since the release of recommendations of the Public Health Faculty/Agency Forum, a national effort designed to expand academic/practice linkages. Has anyone really cared? Has anything really changed? Indeed, the academic community in particular has responded by integrating more public health practice into teaching, research, and service. This article explores where progress has been made and where continuing efforts still are needed. In addition, potential ways to continue enhancing academic/practice linkages are discussed.

Diffusion of Innovation↗
PubMed2000

Building the science base for public health practice.

This article explores the need for and current state of the science base in public health practice. In addition, it discusses how the National Public Health Performance Standards Program will help build the science base in the future and how this can have a positive effect on public health practice and community health status.

Diffusion of Innovation↗