Search PubMed⌕ Search

Biomedical subjects

B Wolf

Publications and source records attributed to B Wolf.

At least 73 records · Page 4Linked to original sources
PubMed1999

Acquired microcephaly after low Apgar score in Zimbabwe.

Serial head circumference measurements were made on 165 African babies born with a 5 min Apgar score of 5 or less. Measurements were taken at birth and at 4, 9, and 12 months of age. In the majority of infants the onset of microcephaly could be diagnosed as early as 4 months of age. Twenty-five of the 142 infants were microcephalic at 1 year. Neurological development was impaired in 19 of the 25 (76 per cent) microcephalic infants and in 18 of the 117 (15 per cent) normocephalic infants. Fourteen of the 16 (88 per cent) infants with severe quadriplegia developed microcephaly before the age of 4 months. A decreased rate of head growth during the first 4 months of life in African infants born with a low Apgar score correlates closely with the development of microcephaly. Infants with an acquired microcephaly have a high probability of developing neurologic impairment by the age of 1 year. Serial head circumference measurement in low Apgar score babies in developing countries is an easy, simple, and inexpensive method to detect microcephaly.

Analysis of Variance↗
PubMed1999

Role of TNF-alpha in local surgical trauma-induced microvascular dysfunction.

BACKGROUND/AIM: The aim of this study was to gain insight into the mechanisms of microvascular dysfunction after local surgical trauma. METHODS: The effect of anti-tumor necrosis factor (TNF)-alpha antibody (Ab) on microvascular function, including arteriolar diameter response, nutritive perfusion, leukocyte-endothelial cell interaction and endothelial integrity disruption, was studied in hamster skinfold chamber preparations using intravital fluorescence microscopy. RESULTS: Directly after the surgical procedure, arteriolar diameters were found to be markedly (p < 0.05) reduced, but recovered significantly at 8 h and reached plateau levels after 24 h. Surgical trauma further induced a strong inflammatory response characterized by a significant (p < 0.05) increase in leukocyte adherence to the endothelium of postcapillary venules. This inflammatory response was associated with an increase in microvascular permeability, indicating endothelial integrity disruption. Anti-TNF-alpha Ab had no significant effect on the surgical trauma-induced arteriolar vasomotor dysfunction; however, it effectively (p < 0.05) reduced venular leukocyte adherence and attenuated the increase in microvascular permeability. CONCLUSION: Our study indicates that arteriolar constriction, leukocyte-endothelial cell interaction and endothelial macromolecular leakage have to be considered as the characteristic microvascular response after local surgical trauma. It is conceivable that TNF-alpha plays a role in mediating the inflammatory response, but not the dysfunction of vasomotor control.

Animals↗
PubMed1999

Mutations causing profound biotinidase deficiency in children ascertained by newborn screening in the United States occur at different frequencies than in symptomatic children.

Biotinidase deficiency is an autosomal recessive disorder of biotin metabolism that can lead to varying degrees of neurologic and cutaneous symptoms when untreated. Because this disorder meets the criteria for newborn screening, many states and countries perform this testing. Because newborn screening should result in complete ascertainment of mutations causing profound biotinidase deficiency (less than 10% of mean normal serum activity), we compared the mutations in a group of 59 children with profound biotinidase deficiency who were identified by newborn screening in the United States with 33 children ascertained by exhibiting symptoms. Of the 40 total mutations identified among the two populations, four mutations comprise 59% of the disease alleles studied. Two of these mutations occur in both populations, but in the symptomatic group at a significantly greater frequency. The other two common mutations occur only in the newborn screening group. Because two common mutations do not occur in the symptomatic population, it is possible that individuals with these mutations either develop mild or no symptoms if left untreated. However, inasmuch as biotin treatment is inexpensive and innocuous, it is still recommended that all children with profound biotinidase deficiency be treated.

Amidohydrolases↗
PubMed1999

Combined restorative proctocolectomy and pancreaticoduodenectomy for familial adenomatous polyposis.

This is a case report on FAP in a 41-year-old woman in which preoperative examination showed a giant tubulovillous adenoma of the descending duodenum surrounding the papilla of Vater, in addition to pancolon adenomatous polyposis, and isolated adenomas in the gastric antrum and corpus. As it was impossible to remove the giant villous adenoma in the duodenum endoscopically, prophylactic surgical treatment was chosen consisting of restorative proctocolectomy and additional pancreaticoduodenectomy. Flat tubulovillous adenomas in the gastric corpus were successfully removed by total snare biopsies before operation. FAP coli patients treated by prophylactic surgery are now known to be at risk of developing adenomas anywhere in the intestine and many affected patients later die from upper gastrointestinal tumors. In this single case report, the simultaneous occurrence of FAP coli and giant villous adenoma of the duodenum indicates the frequent outcome of this genetic alteration requiring lifelong surveillance. This rare case report includes a short survey of the relevant literature.

Adenomatous Polyposis Coli↗
PubMed1999

[Utilization of dental services--results of an oral hygiene study in Saxony].

The utilisation of dental services is a precondition for professional preventive measures. The representative oral survey "Bevölkerungsrepräsentative Studie zum zahnärztlich-prothetischen Versorgungsgrad und Behandlungsbedarf" aimed at gaining data on the frequency and motives for dental visits and the existence of barriers. The sample consisted of 714 subjects aged fifteen years and older. It was representative for the German Federal State Saxony. Socio-economic and behavioural data were collected via self-completed questionnaire. The caries history was evaluated by assessing the DMFT Index. Data collection in 1996 was carried out by three calibrated dentists. Utilisation of dental services was found to be high. Subjective barriers played no crucial role in the decision to utilise dental services. Costs as an objective barrier to dental visits had a growing importance with age. Lower rates of tooth loss and enhanced levels of restoration were found in subjects aged over 24 years who regularly utilised dental services compared to subjects with non-regular utilisation. These differences were significant for subjects over 54 years (tooth loss) and subjects aged 25-44 years and over 54 years (level of restoration). Compared to previous studies the utilisation was similar or higher in our sample. The enhanced oral health belief paves the way for professional preventive measures. In the over 64-year-olds the need for regular dental visits was obvious and this age group must definitely be given more relevant information on the subject.

Adolescent↗
PubMed1998

Neonatal neurological examination as a predictor of neuromotor outcome at 4 months in term low-Apgar-score babies in Zimbabwe.

The predictive value of the neonatal neurological examination (NNE) adapted from Prechtl, was investigated in 139 term Zimbabwean infants born with an Apgar score of five or less at 5 min. At 4 months, seven infants had died and 13 were lost to follow-up, leaving 119 infants to undergo the Infant Motor Screen (IMS). Eighty-eight infants were diagnosed as normal, six as suspect and 25 as abnormal at screening. The sensitivity, specificity, positive predictive value and negative predictive value of the NNE were 94%, 55%, 42% and 96%, respectively. Seventeen (14%) infants had developed microcephaly at 4 months and 13 (77%) of them scored abnormal on the IMS. Twenty-three of the 48 (48%) infants who had convulsions within 48 h of birth, were diagnosed as abnormal (P < 0.0001). The NNE proved to be very sensitive in detecting neurodevelopmental abnormalities in the neonatal period and the five abnormal syndromes derived from the NNE were able to correctly identify 94% of the abnormal infants.

Adolescent↗
PubMed1998

Monitoring of cellular signalling and metabolism with modular sensor-technique: the PhysioControl-Microsystem (PCM).

Microsensors provide instruments particularly suited for the noninvasive analysis of cell and tissue cultures. The outstanding benefit lies in the passive behaviour of continuously working transducers, which in turn allows the dynamic recording of function-specific cellular processes. The microsensor system presented in this paper is a modular arrangement of various planar and non-planar sensor elements surrounding small cell culture chambers. An optic access to the cultures (e.g. for high resolution light microscopy and spectro-photometric techniques) enables a parallel and comparative data acquisition. The system was originally designed for biomedical research in chemotherapy and pharmacology but it proved to be an effective device both for toxicological and environmental research.

Biosensing Techniques↗
PubMed1998

Double mutation (A171T and D444H) is a common cause of profound biotinidase deficiency in children ascertained by newborn screening the the United States. Mutations in brief no. 128. Online.

Biotinidase deficiency is inherited as an antosomal recessive trait that, unless treated with pharmacologic doses of biotin, can result in neurologic and cutaneous symptoms. We have identified two new mutations in exon D of the biotinidase gene of children with profound biotinidase deficiency ascertained by newborn screening. Transition 511G->A near the 5' end of exon D results in a substitution of threonine for alanine 171 (A171T) and transversion 1330G->C occurs close to the 3' end of exon D causing a substitution of histidine for aspartic acid 444 (D444H). The D444H mutation was detected in four individuals from our normal population whose mean serum biotinidase activity is 5.25 nmol/min/ml, which is significantly lower than the mean normal activity (7.1 nmol/min/ml). We calculated that this mutation causes a 52% loss of activity in the aberrant enzyme. Twenty-three individuals with the D444H mutation were found by allele specific oligonucleotide analysis of DNA from 296 randomly-selected, anonymous dried-blood spots. We estimate the frequency of this allele in the general population to be 0.039. In contrast, no individuals in 376 have the A171T mutation. Fourteen children (eleven probands and three siblings) out of the 31 enzyme-deficient children have both the A171T and D444H mutations. Both mutations are inherited from a single parent as a double mutation allele. The nine families in which this allele was identified are of mostly European ancestry, although the mutation cannot be attributed to a specific nationality or ethnic group. The serum of a child who is homozygous for the double mutation allele has very little CRM and the aberrant enzyme has very low biotinylhydrolase activity and no botinyl-transferase activity. This double mutation allele (A171T and D444H) is a common cause of profound biotinidase deficience in children ascertained by newborn screening in the United States.

Acyltransferases↗
PubMed1998

Expression pattern of heme oxygenase isoenzymes 1 and 2 in normal and stress-exposed rat liver.

Heme oxygenase (HO) catalyzes the oxidative cleavage of the alpha-mesocarbon of Fe-protoporphyrin-IX yielding equimolar amounts of biliverdin-IXa, iron, and carbon monoxide. The HO-system consists of two isoenzymes, namely HO-2 and the inducible isoform HO-1, also referred to as heat shock protein (hsp) 32. Although both parenchymal and non-parenchymal liver cells participate in heme metabolism, the expression pattern of the isoenzymes in normal and stress exposed liver is unknown. To study this, rats underwent either endotoxin (lipopolysaccharide [LPS]) challenge, hemorrhagic hypotension, glutathione (GSH) depletion, or cobalt chloride injection, all known to provoke oxidative stress. HO-2 messenger RNA (mRNA) and protein were constitutively expressed in hepatocytes, Kupffer/endothelial-, and stellate (Ito-) cell enriched fractions. Although both non-parenchymal cell fractions expressed HO-1 transcripts, HO-1 immunoreactive protein was restricted to Kupffer cells in the normal liver. In contrast to HO-2, a significant increase in HO-1 on the whole organ level was noted by hemorrhagic hypotension, GSH depletion, and cobalt chloride injection. However, the distinct stress models led to a strikingly different cell-type specific and sublobular expression pattern of HO-1 gene expression. HO-1 was inducible in sinusoidal lining cells (hemorrhagic hypotension, LPS challenge), in periportal (cobalt chloride), or pericentral (GSH depletion, hemorrhagic hypotension) hepatocytes. The blockade of protein translation before hemorrhage by cycloheximide reduced upregulation of HO-1/hsp32 mRNA significantly (65.4% reduction, P < .05), whereas the inducibility of hsp70 transcript was maintained. In addition to transcriptional regulation, HO-1 seems to be subject to posttranscriptional control in particular in non-parenchymal cells.

Animals↗
PubMed1998

Mutation in a putative glycosylation site (N489T) of biotinidase in the only known Japanese child with biotinidase deficiency.

The only known Japanese child with biotinidase deficiency was identified by newborn screening in Japan. He has 10.8% of mean normal serum biotinyl-hydrolase activity and trace biotinyl-transferase activity. The mutation results in 16% of normal cross-reacting material in serum with antibody to purified normal biotinidase. He is homozygous for a unique mutation, A1466 > C (Asn489Thr) in exon 4 of the biotinidase gene. The mutation appears to abolish a putative glycosylation site in a region in which other missense mutations have been identified, indicating that this region of the enzyme must be important for enzyme activity. This mutation may affect secretion or stability of the enzyme in serum. Interestingly, this child is now 8 years old, has not been on biotin supplementation for 3 years, and has remained asymptomatic.

Amidohydrolases↗
PubMed1998

On-line control of cellular adhesion with impedance measurements using interdigitated electrode structures.

Critical parameters to be assessed in cell culture are the number of viable cells and cell viability. Growth, product formation, toxicity effects and the overall success of cell culture can depend largely on these. With interdigitated electrode structures (IDES) adherent cells are cultured directly on a pair of interdigitated electrodes, and the impedance of the system gives insight into the adhesive behaviour of the cells. The signal is influenced by the changes in number, growth and morphological behaviour of adherently growing cells, mainly owing to the insulating effects of the cell membranes. Five different cell lines are used, and their divergent behaviour is monitored over a period of four days, from inoculation of the cells to killing of the cells at the end of the experiments. Even when the cells from close monolayers, great fluctuations in the impedance signal can be observed. Nevertheless, for a more complete description of cellular systems, other parameters, such as acidification and respiration, have to be included in the measuring system.

Biosensing Techniques↗
PubMed1998

Structure of the human biotinidase gene.

Biotinidase cleaves biotin from biocytin, thereby recycling the vitamin. We have determined the structure of the human biotinidase gene. A genomic clone, containing three exons that code for the mature enzyme, was obtained by screening a human genomic bacteriophage library with the biotinidase cDNA by plaque hybridization. To obtain a clone containing the most 5' exon of the biotinidase cDNA, a human PAC library by PCR was screened. The human biotinidase gene is organized into four exons and spans at least 23 kb. The 5'-flanking region of exon 1 contains a CCAAT element, three initiator sequences, an octamer sequence, three methylation consensus sites, two GC boxes, and one HNF-5 site, but has no TATA element. The region from nt -600 to +400 has features of a CpG island and resembles a housekeeping gene promoter. The structure and sequence of this gene are useful for identifying and characterizing mutations that cause biotinidase deficiency.

Amidohydrolases↗
PubMed1998

Polyorchidism.

Polyorchidism is defined as the presence of more than two testes. We report the case of a 3-year-old boy and review the embryology and surgical management of the condition.

Child, Preschool↗
PubMed1998

Partial biotinidase deficiency is usually due to the D444H mutation in the biotinidase gene.

Newborn screening for biotinidase deficiency has identified children with profound biotinidase deficiency (<10% of mean normal serum activity) and those with partial biotinidase deficiency (10%-30% of mean normal serum activity). Children with partial biotinidase deficiency and who are not treated with biotin do not usually exhibit symptoms unless they are stressed (i.e., prolonged infection). We found that 18 of 19 randomly selected individuals with partial deficiency have the transversion missense mutation G1330>C, which substitutes a histidine for aspartic acid444 (D444H) in one allele of the biotinidase gene. We have previously estimated that the D444H mutation results in 48% of normal enzyme activity for that allele and occurs with an estimated frequency of 0.039 in the general population. The D444H mutation in biotinidase deficiency is similar to the Duarte variant in galactosemia. The D444H mutation in one allele in combination with a mutation for profound deficiency in the other allele is the common cause of partial biotinidase deficiency.

Alleles↗
PubMed1998

Ophthalmic and genetic screening in pedigrees with familial adenomatous polyposis.

PURPOSE: To study the possible association between ophthalmic findings, genetic status, and clinical course of the disease in Austrian pedigrees with familial adenomatous polyposis (FAP). METHODS: Thirty-nine members of 16 consecutive FAP families with 20 affected patients and 19 relatives with a 50% a priori risk to develop the disease were examined ophthalmologically. The intestinal status of all persons was established by colonoscopy. Direct or indirect molecular genetic analysis, or both, was possible in eight of the 16 FAP families. RESULTS: Congenital hypertrophy of the retinal pigment epithelium (CHRPE) was discovered in 15 (75%) of the 20 persons affected by familial adenomatous polyposis. Five (25%) of the patients with an established FAP were CHRPE-negative. Four of the 19 at-risk individuals were CHRPE-positive. According to DNA analysis, five of the 19 at-risk relatives had a high risk to develop a manifest disease. The ophthalmoscopic tests were in complete agreement with the molecular risk estimation. Furthermore, the combined results of endoscopy and ophthalmoscopy suggested a relationship between a positive CHRPE status and the severity of FAP. CONCLUSIONS: Ophthalmic examinations facilitate predictive diagnosis in FAP patients and first-degree relatives, permitting a noninvasive, highly reliable risk assessment. When present, CHRPE lesions are a reliable clinical marker for FAP in CHRPE-positive families. In CHRPE negative families, negative ophthalmic examinations are of no predictive value. The CHRPE status can add information about the location of the genetic mutation. The combination of an ophthalmic examination with DNA analysis and endoscopy improves the risk assessment of FAP carriers.

Adenomatous Polyposis Coli↗
PubMed1998

Dynamics of biomolecules: assignment of local motions by fluorescence anisotropy decay.

Many biological systems have multiple fluorophores that experience multiple depolarizing motions, requiring multiple lifetimes and correlation times to define the fluorescence intensity and anisotropy decays, respectively. To simplify analyses, an assumption often made is that all fluorophores experience all depolarizing motions. However, this assumption usually is invalid, because each lifetime is not necessarily associated with each correlation time. To help establish the correct associations and recover accurate kinetic parameters, a general kinetic scheme that can examine all possible associations is presented. Using synthetic data sets, the ability of the scheme to discriminate among all nine association models possible for two lifetimes and two correlation times has been evaluated. Correct determination of the association model, and accurate recovery of the decay parameters, required the global analysis of related data sets. This general kinetic scheme was then used for global analyses of liver alcohol dehydrogenase anisotropy data sets. The results indicate that only one of the two tryptophan residues in each subunit is depolarized by process(es) independent of the enzyme's rotations. By applying the proper kinetic scheme and appropriate analysis procedures to time-resolved fluorescence anisotropy data, it is therefore possible to examine the dynamics of specific portions of a macromolecule in solution.

Alcohol Dehydrogenase↗