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Biomedical subjects

B Müller

Publications and source records attributed to B Müller.

At least 325 records · Page 18Linked to original sources
PubMed1991

X-linked centronuclear myopathy: mapping the gene to Xq28.

The X-linked recessive centronuclear/myotubular myopathy (XLR-CNM/MTM1), a severe neonatal disorder characterized by generalized hypotonia, muscle weakness and primary asphyxia, has recently been mapped to Xq28. This report presents linkage analysis data of eight families with X-linked centronuclear myopathy. Four probes from the region Xq26-27 and five Xq28 probes were used to get more precise gene localization and marker order. St14 (DXS52), fully informative in all families, shows significant linkage to the CNM gene (z = 3.60; theta = 0.05), followed by DX13 (DXS15) (z = 2.03; theta = 0.06) and F8 (z = 1.86; theta = 0.00). Combination of the physical map derived by Kenwrick and Gitschier (1989) and our linkage data lead to the most probable order R/GCP-G6PD-(XLR-CNM-F8)-p767-St14-cpX67-++ +DX13 placing the CNM gene close to F8. The results of this study confirm strong linkage of the CNM gene to the region Xq28 and will permit carrier testing and prenatal diagnosis in CNM families. We conclude that the precise localization of this devastating disorder may be of great importance for genetic counselling in families at risk. The lack of information about gene frequency and mutation rate as well as the severity and burden of the disease point to the inevitable need for accurate clinical diagnosis.

Chromosome Mapping↗
PubMed1991

Regenerating axons from adult chick retinal ganglion cells recognize topographic cues from embryonic central targets.

We investigated whether regenerating mature axons recapitulate embryonic features essential to successful reconnectivity within the injured nervous system. Strips from embryonic and adult chick retinae were cultured, and outgrowing axons were examined morphometrically and immunohistochemically. In addition, the target-recognition properties of adult neurites were analyzed. Regenerating adult axons elongate on a poly-L-lysine/laminin substratum with a speed about one order of magnitude slower than that of embryonic axons. Morphologically, adult axonal tips differ dramatically from embryonic growth cones in that they possess only filopodial extensions whereas embryonic growth cones possess both lamellipodial and filopodial processes. Both embryonic and adult neurites express the growth-associated protein GAP-43. When cultured on alternating stripes of anterior and posterior embryonic tectal membranes, both adult and embryonic retinal axons distinguish between the two membrane preparations. Our results demonstrate that during axonal regeneration the mature neurons express embryonic properties that are involved in the recognition of tectal positional cues.

Animals↗
PubMed1991

Rod bipolar cells in the cone-dominated retina of the tree shrew Tupaia belangeri.

The tree shrew has a cone-dominated retina with a rod proportion of 5%, in contrast to the common mammalian pattern of rod-dominated retinae. As a first step to elucidate the rod pathway in the tree shrew retina, we have demonstrated the presence of rod bipolar cells and studied their morphology and distribution by light and electron microscopy. Rod bipolar cells were labeled with an antiserum against the protein kinase C (PKC), a phosphorylating enzyme. Intense PKC immunoreactivity was found in perikarya, axons, and dendrites of rod bipolar cells. The cell bodies are located in the sclerad part of the inner nuclear layer, the dendrites ascend to the outer plexiform layer where they are postsynaptic to rod spherules, and an axon descends towards the inner plexiform layer (IPL). The axons branch, and terminate in the vitread third of the IPL where mammalian rod bipolar cells are known to terminate. Two amacrine cell processes are always seen as the postsynaptic elements (dyads). Dendritic and axonal arbors of rod bipolar cells are rather large, up to 100 microns in diameter. The topographical distribution of the rod bipolar cells was analyzed quantitatively in tangential sections. Their density ranges from 300 cells/mm2 in peripheral retina to 900 cells/mm2 more centrally. The distribution is rather flat with no local extremes. Consistent with the low rod proportion in tree shrew, the rod bipolar cell density is low compared to the rod-dominated cat retina for example (36,000-47,000 rod bipolar cells/mm2). Rod-to-rod bipolar cell ratios in the tree shrew retina range from smaller than 1 to about 7, and thus are also lower than in cat.

Animals↗
PubMed1991

Serological (Em2-ELISA) and parasitological examinations of fox populations for Echinococcus multilocularis infections.

Serum or body fluid samples of 1,006 foxes were investigated in an ELISA for antibodies against a highly sensitive and specific antigen (Em2-antigen) of Echinococcus multilocularis. Parasitological examinations of the intestines and simultaneous serological examinations were carried out in 505 foxes: A group of 98 blue foxes (Alopex lagopus) from Norwegian fox farms did not contain intestinal stages of E. multilocularis and was clearly sero-negative in Em2-ELISA. On the other hand in red foxes (Vulpes vulpes) originating from European areas known to be endemic for E. multilocularis the following average prevalence rates were found: 244 foxes from Southern Germany, E. multilocularis prevalence 55% and sero-prevalence 60%; 139 foxes from Austria, E. multilocularis prevalence 4% and sero-prevalence 12%. Serological identification of individual foxes with or without intestinal E. multilocularis infection was not possible. Only serological (no parasitological) examination in 402 foxes originating from endemic areas in Switzerland resulted in a sero-prevalence rate of 37%. Sero-prevalence was only 6% and 4% in 54 and 26 other foxes, respectively, originating from Swiss and German areas where E. multilocularis has not yet been reported. Negative control Norwegian (farmed) silver foxes (n = 43) were all sero-negative. The specificity of the Em2-ELISA was confirmed by negative Em2-serologies with sera from dogs infected with intestinal and tissue dwelling helminth species (with the exception of two from 24 dogs infected with E. granulosus).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

A test based on the exact probability distribution of the chi 2 statistic--incorporation into the MASC method.

The MASC method (Clerget-Darpoux et al. 1988) to test genetic models in HLA associated disease makes use of a test of goodness-of-fit on categorized data. This test is composed of a sum of independent chi 2s, which are applicable only when expectations in each category are not too small. The commonly used approach to solve this problem is to combine classes in order to raise expectations. This, however, means losing some of the information contained in the data and may decrease greatly the power of discrimination between models. A test based on the exact probability distribution of a test statistic, namely the chi 2, has been implemented to avoid this dilemma.

Chi-Square Distribution↗
PubMed1991

[The effective half-life of 131I during the treatment of autonomous thyroid disease with radioiodine].

In order to compute effective half-life of 131I after application of therapeutic doses (Teff), the time course of whole-body radioactivity was evaluated retrospectively in 115 patients with benign thyroid diseases (multinodular autonomous adenoma, solitary autonomous adenoma or Graves' disease). Because of a large overlap of Teff in the various diseases analyzed, courses of all patients who did (group Ts, 24 cases) or did not (group kTs, 91 cases) receive antithyroid drugs during therapy were summarized. In group Ts a mean Teff of 5.0 +/- 0.9 d was found which was significantly (p less than 0.01) lower than the mean Teff of 6.3 +/- 0.9 d in group kTs. We believe that the mean Teff is a practical alternative in radioiodine dosimetry if an exact determination of Teff cannot be performed because of shortage of time.

Adenoma↗
PubMed1991

Skeletal muscle ultrastructural alterations in a case of Guillain-Barre syndrome.

The structural study of a muscle biopsy from a case of Guillain-Barré syndrome showed the typical findings of neurogenic atrophy and several abnormalities not commonly observed in denervated muscle as fibre necrosis, capillary alterations and infiltration of macrophages and occasional mast cells. The histopathological picture was similar to that found in the muscular compromise of some autoimmune diseases. The possibility for an immune mechanism in the muscle damage of Guillain-Barré syndrome is discussed.

Adolescent↗
PubMed1991

[Comparative studies on the effect of nasal CPAP, theophylline and oxygen in patients with sleep apnea syndrome].

In patients with sleep apnea-syndrome nasal CPAP-therapy is the method of choice. The apnea phases are practically completely eliminated. However some patients with SAS don't accept CPAP-therapy. In this group Theophylline or O2-therapy respectively is discussed. We examined therefore 21 patients (55.8 +/- 9 years) with sleep-apnea syndrome and an apnea-index of 39 +/- 19.9 during 4 consecutive nights (diagnosis, nCPAP-therapy, O2-therapy by 21/min, by nasal prongs and Theophylline 375-400 mg in the evening and calculated apnea-index, the longest apnea and the lowest O2-saturation. On CPAP the number of apneas was practically reduced to 0. On Theophylline there was a relevant reduction of the apnea frequency. On O2-therapy only few patients with non-compliance Theophylline-therapy can be of some benefit in patients with moderate sleep-apnea syndrome. However the apnea-index cannot be normalized.

Humans↗
PubMed1991

[Serum and erythrocyte zinc, copper, magnesium and iron in women with normal pregnancies and pregnancy-at-risk (pregnancy-induced hypertension, fetal growth retardation and hepatosis)].

In women with normal pregnancy and with pathological pregnancy (pregnancy-induced hypertension, fetal growth retardation, hepatosis) trace elements concentrations (Fe++, Cu++, Zn++, Mg++) were determined in serum and erythrocytes. The concentrations were partly decreased or increased in both serum and erythrocytes, but these changes were not significant. Thus, the analyses of trace element concentrations can not be used as a marker of the investigated pathological events of pregnancy.

Copper↗
PubMed1991

[Generalized tendomyopathy (fibromyalgia)].

The generalised tendomyopathy (fibromyalgia) is one of the most frequent rheumatological diseases and has a prevalence of approximately 1%. Multilocular conditions of pain of the back, the extremities and the face with increased tenderness on pressure on defined insertions and courses of the tendons clinically stand to the fore. Functional disturbances, vegetative symptoms and psychopathologic changes are frequently connected with this. Laboratory investigations are normal. The diagnosis results from the combination of multilocular conditions of pain - combined with the defined tenderness on pressure mentioned and as additional symptoms functional disturbances, vegetative symptoms and psychopathological changes. In the genesis of the disease probably reflex mechanisms on the part of the spinal column, partly also on the peripheral joints primarily play a role. Probably the generalisation is evoked above all by psychosocial factors which possibly cause the various symptoms by a continuous impulse on the reticular formation.

Adult↗
PubMed1991

[Behavior of selenium in serum and erythrocytes in females with normal and risk pregnancy (pregnancy-induced hypertension, fetal retardation and hepatosis)].

In the course of normal pregnancy the selenium concentration in serum decreases significantly. The selenium concentration is enhanced in pregnant women with intrauterine growth retardation or hepatosis and unchanged in those with pregnancy-induced hypertension in comparison with healthy pregnant women. In our investigations no changes of the intracellular selenium concentrations in erythrocytes were measured in normal as well as in pathological pregnancy.

Erythrocytes↗
PubMed1991

[Lipid peroxidation in pathologic pregnancy: pregnancy-induced hypertension. I].

Serum concentrations of thiobarbituric acid reagible substance (TBARS) as indicator of lipid peroxidation, alpha-tocopherol and selen have been investigated in women with normal pregnancy and patients suffered from pregnancy-induced hypertension. In the group of patients with pregnancy-induced hypertension we observed an increase in serum concentration of TBARS, where as the serum concentrations of alpha-tocopherol and selen were unchanged. There was no correlation between increase in TBARS concentration and the severity of hypertension.

Blood Pressure↗