Development and application of a nonradioactive nucleic acid hybridization system for simultaneous detection of four potato pathogens

cDNA clones of potato virus X (PVXcp strain), potato virus Y (PVYo strain), potato leaf roll virus (PLRV) and potato spindle tuber viroid (PSTV) were used separately or combined for the detection of the corresponding RNAs in extracts of infected plants. A general method for the rapid preparation of RNA extracts without use of organic solvents (i.e. phenol) was developed for this purpose. Plant extracts from a range of field, artificially inoculated germplasm genotypes, micro-propagated and protoplast samples, as well as vector insect extracts, were dot-blotted onto nylon or nitrocellulose membranes, subjected to sandwich nucleic acid hybridization with non-labelled specific single-stranded DNA probes followed by a biotin-labelled second step hybridization probe. Each probe was virus-specific but not strain-specific. Healthy or non-related plant extracts developed very faint or no signals. Sensitivity was tested by slot-blot hybridization. Detection levels were between 1.5 to 6 pg of viral nucleic acids and between 20 to 50 times more sensitive than standard double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). The assay developed was tested with material that was prepared for processing in the field (combination of fresh sap with extraction solution) and tested under simple laboratory conditions for detection. It was also successfully employed for screening of germplasm for virus resistance, detection of pathogens in vector insects, plantlets grown in vitro and in more sophisticated quantitative determinations of viral replication in artificially inoculated plants and protoplasts.     

Phosphatidylcholine-Specific Phospholipase C from Listeria monocytogenes Is an Important Virulence Factor in Murine Cerebral Listeriosis

Meningoencephalitis is a serious and often fatal complication of Listeria monocytogenes infection. The aim of the present study was to analyze the role of internalin A (InlA) and B, which are involved in the invasion of L. monocytogenes into cultivated host tissue cells, and that of phosphatidylcholine-specific phospholipase C (PlcB), which mainly promotes the direct cell-to-cell spread of L. monocytogenes, in murine cerebral listeriosis by use of an InlA/B (ΔinlAB2)- and a PlcB (ΔplcB2)-deficient isogenic deletion mutant strain and the wild-type (WT) L. monocytogenes EGD. Listeria strains were directly applied to the brain, a technique which has been employed previously to study the pathogenesis of cerebral listeriosis (D. Schlüter, S. B. Oprisiu, S. Chahoud, D. Weiner, O. D. Wiestler, H. Hof, and M. Deckert-Schlüter, Eur. J. Immunol. 25:2384–2391, 1995). We demonstrated that PlcB, but not InlA or InlB, is an important virulence factor in cerebral listeriosis. Nonimmunized mice infected intracerebrally with the ΔplcB2 strain survived significantly longer and had a reduced intracerebral bacterial load compared to mice infected with the ΔinlAB2 strain or WT bacteria. In addition, immunization with the WT prior to intracerebral infection significantly increased the survival rate of mice challenged intracerebrally with the ΔplcB2 strain compared to that of mice infected with the WT or ΔinlAB2 strain. Histopathology revealed that the major difference between the various experimental groups was a significantly delayed intracerebral spread of the ΔplcB2 mutant strain, indicating that cell-to-cell spread is an important pathogenic feature of cerebral listeriosis. Interestingly, irrespective of the Listeria mutant used, the apoptosis of hippocampal and cerebellar neurons and an internal hydrocephalus developed in surviving mice, indicating that these complications are not dependent on the virulence factors InlA/B and PlcB. In conclusion, this study points to PlcB as a virulence factor important for the intracerebral pathogenesis of murine L. monocytogenes meningoencephalitis.     

Hb FM-Fort Ripley: Confirmation of autosormal dominant inheritance and diagnosis by PCR and direct nucleotide sequencing

We describe a normal neonate who presented at four days of age with asymptomatic cyanosis. There was no evidence of cardiac or pulmonary abnormality and an extended family history included 13 other affected family members with asymptomatic cyanosis lasting one to three months. Polymerase chain reaction (PCR) amplification and direct nucleotide sequencing of the proband's Gγ chain gene revealed the mutation at codon 92 (CAC→TAC) previously shown in haemoglobin FM-Fort Ripley (α₂γ₂^{Gγ 92 (F8) His→Tyr}). This is the first family with Hb FM-Fort Ripley reported so far. It demonstrates autosomal dominant inheritance of this condition and incomplete penetrance. © 1994 Wiley-Liss, Inc.     

Seroquel (ICI 204 636), a putative “atypical” antipsychotic,in schizophrenia with positive symptomatology: results of an open clinical trial and changes of neuroendocrinological and EEG parameters

Preclinical data indicated that seroquel (ICI 204 636), a dibenzothiazepine with 5-HT₂ and D₂-like receptor antagonistic properties, might be an effective antipsychotic agent, causing fewer extrapyramidal side effects than typical neuroleptics. In the present study, 12 patients suffering from schizophrenia or schizophreniform disorder with predominantly positive symptomatology were treated in an open clinical trial for 4 weeks with seroquel at a maximum dosage of 750 mg/day. The drug was generally well tolerated, and virtually no adverse extrapyramidal side effects such as acute dystonia, parkinsonism or akathisia were observed. Total scores for BPRS (item score 0–6; baseline: 42.0±2.3; mean±SeM), SAPS (64.5±4.8) and SANS (55.0±4.3) showed a moderate decrease at the end of treatment (BPRS: 30.0±3.5; SAPS: 36.1±6.7; SANS: 42.5±5.9), when intention-to-treat analysis was applied. There were considerable interindividual differences in treatment response, with some subjects showing almost full remission of positive symptoms, in contrast to about half of the patients who showed no satisfactory clinical improvement. Interestingly, patients showing good antipsychotic response reported slight initial side effects like mild sedation. Prolactin and TSH levels were not altered during seroquel administration. As to pharmaco-EEG investigations, seroquel caused a moderate increase of the absolute power in the alpha, theta, and beta frequency bands, paralleled by a decrease of delta activity. There were no signs of paroxysmal EEG activity under seroquel. Our results suggest that seroquel may be a well tolerated drug with some antipsychotic properties, exhibiting no extrapyramidal side effects that could be of use in the treatment of schizophrenic patients with positive symptomatology. Further double-blind studies with higher doses, in order to test presumably better efficacy, and with monitoring of plasma levels, are needed to extend the present results.     

Initial manifestation of a manic syndrome in advanced age in subcortical arteriosclerotic encephalopathy (Binswanger disease)

We describe the case of a 65-year old man who presented with a first episode of mania lacking a history of previous affective illness. Clinical, neuropsychological and NMR-findings pointed to a subcortical arteriosclerotic encephalopathy (Morbus Binswanger) as an underlying organic condition. According Kleman's concept of "secondary mania" this case illustrates the necessity a thorough search for organic conditions in late manifesting affective illness which may also involve therapeutic considerations.     

Combined chemotherapy-radiotherapy study of small cell bronchial carcinoma: chemo-/radiotherapy vs radio-/chemotherapy

The authors studied the effect of a chemo-/radiotherapy or radio-/chemotherapy on 52 cases of microcellular bronchial carcinoma, classification "limited disease". The survival curves were slightly better for the patients submitted to primary chemotherapy, but the difference was not statistically significant, and the curves coincided again after 18 months. 60 to 80% of the patients had no complaints or only unimportant complaints during more than half of their survival time. In 23 patients with "extensive disease" who received only a symptomatic therapy or a combined palliative chemotherapy, chemotherapy had a slightly better effect, but this was not statistically significant.