Mlh1 can function in antibody class switch recombination independently of Msh2.

Mismatch repair proteins participate in antibody class switch recombination, although their roles are unknown. Previous nucleotide sequence analyses of switch recombination junctions indicated that the roles of Msh2 and the MutL homologues, Mlh1 and Pms2, differ. We now asked if Msh2 and Mlh1 function in the same pathway during switch recombination.

Extent of damage in ischemic, nonreperfused, and reperfused myocardium of anesthetized rats.

To investigate the localization of the earliest damage in ischemic and ischemic-reperfused myocardium, anesthetized rats were subjected to coronary occlusion for 15, 30, 45, or 90 min. One-half of the animals in each group had no reperfusion, whereas the other half was reperfused for 14 min. With the use of histological methods, preferentially in the periphery of the area at risk, localized zones were detected that lacked the hypoxia-specific increase in NADH fluorescence.

Transforming growth factor beta in chronic obstructive sialadenitis of human submandibular gland.

Background: The exact pathomechanism of inflammation progress and fibrosis in chronic obstructive sialadenitis is unknown. The aim of the present study was to assess whether there is an association between transforming growth factor beta (TGF-beta) and fibrogenic process of chronic sialadenitis.

Methods: Tissue samples of 12 patients with chronic sialadenitis and 4 normal tissue samples of the submandibular gland were examined immunohistochemically for identification of TGF-beta.

Genetic characterization of a porcine H1N2 influenza virus strain isolated in Germany.

We examined selected influenza virus strains from various outbreaks of respiratory diseases among pigs in Germany. Besides H3N2 and H1N1 subtypes presently circulating in Europe, an H1N2 influenza virus was isolated in 2000. Sequence analysis of hemagglutinin, neuraminidase and matrix genes indicated that this virus is a reassortant of human H1N1 and human H3N2 strains with an internal gene, the M gene of avian origin.

[N-methyl 11C]meta-Hydroxyephedrine positron emission tomography in Parkinson's disease and multiple system atrophy.

Orthostatic hypotension (OH) can be present in idiopathic Parkinson's disease (IPD) as well as in atypical parkinsonian syndromes such as multiple system atrophy (MSA). According to clinical tests of sympathetic nerve function and histopathological data, OH is caused by primarily postganglionic sympathetic dysfunction in IPD and by predominantly central and preganglionic degeneration in MSA. It has been proposed that this concept of a different underlying pathogenesis for OH should be applied in the differential diagnosis of parkinsonian disorders, in the form of measurements of sympathetic myocardial innervation.

Increased intracortical inhibition in middle-aged humans; a study using paired-pulse transcranial magnetic stimulation.

Using single and paired-pulse transcranial magnetic stimulation we compared the cortical excitability in two different age groups of healthy subjects (mean+/-SD age: 28.5+/-5.2 vs.

[Studies on the importance of tick-borne encephalitis in Rhineland-Pfalz].

Within the scope of a prospective clinical study during 2001 in Rhineland-Palatinate specimen from sera and cerebrospinal fluids of 163 patients with suspected meningitis were controlled in an enzyme immunoassay concerning a TBE infection. Questionable results were checked via a neutralisation test. In no case such an infection was confirmed.

Effects of subthalamic nucleus (STN) stimulation on motor cortex excitability.

Background: Deep brain stimulation of the internal global pallidus (GPi) and the subthalamic nucleus (STN) has become a treatment alternative in advanced PD. Although the effects of GPi stimulation have been examined recently, little is known about STN stimulation effects on motor cortex excitability.

Methods: The effects of STN stimulation were studied in eight patients with advanced PD using paired-pulse transcranial magnetic stimulation (TMS) in comparison with healthy control subjects.

Chronic sclerosing sialadenitis of the submandibular gland is mainly due to a T lymphocyte immune reaction.

The aim of our study was to investigate the role of immunopathological processes in the pathogenesis of chronic sclerosing sialadenitis of submandibular glands (Küttner tumor). For this purpose, biopsy specimens from submandibular glands of 22 patients with the histological diagnosis of chronic sclerosing sialadenitis were analyzed. Paraffin-embedded tissues were immunostained for T-lymphocyte subsets (CD3, CD4, CD8), cytotoxic T cells (granzyme B), B cells (CD20, Ki-B3), and macrophages (Ki-M1P).

Characterization of tick-borne encephalitis (TBE) foci in Germany and Latvia (1997-2000).

Knowledge concerning the prevalence of the tick-borne encephalitis virus (TBEV) in wild living tick populations is very important for understanding the epidemiology of the disease and for immuno prophylactic strategy. In Germany high and low risk areas of TBE exist. In the years 1997-2000, 533 autochthonous clinical TBE cases were recorded, in the high-risk areas of Bavaria and Baden-Wuerttemberg 140 and 363, and in the low risk areas in Hesse (Odenwald) and Rhineland-Palatinate 22 and 8, respectively.

The ubiquitously expressed DNA-binding protein late SV40 factor binds Ig switch regions and represses class switching to IgA.

Ig heavy chain class switch recombination (CSR) determines the expression of Ig isotypes. The molecular mechanism of CSR and the factors regulating this process have remained elusive. Recombination occurs primarily within switch (S) regions, located upstream of each heavy chain gene (except Cdelta).

Role for mismatch repair proteins Msh2, Mlh1, and Pms2 in immunoglobulin class switching shown by sequence analysis of recombination junctions.

B cells from mice deficient in mismatch repair (MMR) proteins show decreased ability to undergo class switch recombination in vitro and in vivo. The deficit is not accompanied by any reduction in cell viability or alterations in the cell cycle in B cells cultured in vitro. To assess the role of MMR in switching we examined the nucleotide sequences of Smicro-Sgamma3 recombination junctions in splenic B cells induced in culture to switch to IgG3.

The mu switch region tandem repeats are important, but not required, for antibody class switch recombination.

Class switch DNA recombinations change the constant (C) region of the antibody heavy (H) chain expressed by a B cell and thereby change the antibody effector function. Unusual tandemly repeated sequence elements located upstream of H chain gene exons have long been thought to be important in the targeting and/or mechanism of the switch recombination process. We have deleted the entire switch tandem repeat element (S(mu)) from the murine (mu) H chain gene.

Annual and seasonal variation of tick-borne encephalitis virus (TBEV) prevalence in ticks in selected hot spot areas in Germany using a nRT-PCR: results from 1997 and 1998.

The prevalence of tick-borne encephalitis virus (TBEV) in Ixodes ricinus tick populations in endemic areas of Germany with the highest TBE risk is unknown. Annual and seasonal differences in TBEV prevalence have also not been studied. Against this background, in May 1997 we started a systematic virus surveillance programme in ticks collected in locations known to have a high incidence of autochthonous TBE cases.

Step-by-step description of a rotary root canal preparation technique.

CLINICAL TECHNIQUE: Since the introduction of nickel-titanium in endodontics, several canal preparation techniques involving the use of rotary instruments have become popular. Such engine-driven rotary instruments rotate between 150 and 2000 r.p.

A nested RT-PCR for the detection of tick-borne encephalitis virus (TBEV) in ticks in natural foci.

We have developed a sensitive nested reverse-transcriptase polymerase chain reaction assay (n RT-PCR) for the detection of the tick-borne encephalitis virus (TBEV) RNA, especially in ticks. The primer pairs were selected from the 5'-terminal noncoding region, a highly conserved part of the virus. The specificity was tested by computer homology searches of sequences as well as by the sequencing of the first and second amplificate, by Southern blot hybridization with a DIG-labelled oligonucleotide probe, and by restriction enzyme analysis.

Reduced isotype switching in splenic B cells from mice deficient in mismatch repair enzymes.

Mice deficient in various mismatch repair (MMR) enzymes were examined to determine whether this repair pathway is involved in antibody class switch recombination. Splenic B cells from mice deficient in Msh2, Mlh1, Pms2, or Mlh1 and Pms2 were stimulated in culture with lipopolysaccharide (LPS) to induce immunoglobulin (Ig)G2b and IgG3, LPS and interleukin (IL)-4 to induce IgG1, or LPS, anti-delta-dextran, IL-4, IL-5, and transforming growth factor (TGF)-beta1 to induce IgA. After 4 d in culture, cells were surface stained for IgM and non-IgM isotypes and analyzed by FACS((R)).

Evaluating the sizes of Lightspeed instruments.

The diameters of six different sized Lightspeed cutting heads were measured using a modified optical micrometer. Six specimens of instrument sizes 20, 22.5, 27.

Viral zoonosis from the viewpoint of their epidemiological surveillance: tick-borne encephalitis as a model.

Tick-borne encephalitis (TBE) is a vector borne and, more rarely, a food (milk, milk products) borne disease of humans. For further characterization of the virus activity in natural foci of TBE more than 32,000 unengorged wild ticks were caught in low and high virus active foci in Germany (Mecklenburg-Western Pomerania, Saxony, Brandenburg, Thuringia, Bavaria, Baden-Württemberg, Saarland). The ticks were examined by RT-PCR and Southern blot hybridization as well as by classical virological methods.

Cognate T cell help for CD40-deficient B cells induces c-myc RNA expression, but DNA synthesis requires an additional signal through surface Ig.

To investigate the role of CD40 ligand in the delivery of help to B cells, we examined the Ag-specific interaction of B cells from CD40-deficient mice with a Th2 cell line in vitro. Small resting B cells from normal mice are stimulated to synthesize DNA when they present monovalent Ag (rabbit Fab anti-Ig) to a rabbit Ig-specific Th cell line. This response, which is independent of a signal through the B cell Ag receptor (sIg), is nearly absent in B cells from CD40-deficient mice.