Cholelithiasis prevalence and risk factors in individuals with severe or profound intellectual and motor disabilities.

BACKGROUND: The prevalence and risk factors of cholelithiasis in individuals with severe or profound intellectual and motor disabilities (SPIMD) are poorly characterised. Thus, we aimed to investigate the prevalence and risk determinants of cholelithiasis in a cohort with SPIMD under medical care in a residential facility. METHODS: We categorised 84 patients in a residential hospital for persons with SPIMD into groups: those with (Group CL) and without (Group N) cholelithiasis. Gallstones were detected via computed tomography, ultrasonography or both. We evaluated gastrostomy status, nutritional and respiratory support, constipation, and bladder and kidney stones. Data were significantly analysed using univariate and multivariate logistic regression analyses. RESULTS: The prevalence rate of cholelithiasis in our SPIMD cohort was 27%. There were no significant differences in sex, age, weight, height, or Gross Motor Function Classification System between the two groups. However, more patients received enteral nutrition (39.13% vs. 6.56%; P = 0.000751) and were on ventilator support (56.52% vs. 19.67%; P = 0.00249) in Group CL than in Group N. Enteral nutrition [odds ratio (OR) 10.4, 95% confidence interval (CI) 1.98-54.7] and ventilator support (OR 20.0, 95% CI 1.99-201.0) were identified as independent risk factors for the prevalence of cholelithiasis in patients with SPIMD. CONCLUSIONS: Patients with SPIMD demonstrated an increased prevalence of cholelithiasis, with a notable association between nutritional tonic use and respiratory support. Therefore, to emphasise the need for proactive screening, it is crucial to devise diagnostic and therapeutic strategies specific to patients with SPIMD. Further investigation is essential to validate our findings and explore causative factors.

In vitro processing of amyloid precursor protein by cathepsin D.

The formation of beta A4 amyloid in the brains of individuals with Alzheimer's disease requires the proteolytic cleavage of amyloid precursor protein. Several lines of evidence suggest that cathepsin D, the major lysosomal/endosomal aspartic protease, may be involved in this process. In this work, we used a sensitive in vitro method of detection to investigate the role of cathepsin D in the proteolytic processing of a 100-amino acid C-terminal fragment (C100) inclusive of beta A4 and cytoplasmic domain of APP. Digestion of C100 with cathepsin D resulted in cleavage at the amyloidogenic gamma-cleavage sites. This occurred preferentially at Thr43-Val44 and at Ala42-Thr43, generating full length beta A4 43 and beta A4 42 amyloid peptides, respectively. Cathepsin D was also found to cleave the substrate at the following nonamyloidogenic sites; Leu34-Met35, Thr48-Leu49 and Leu49-Val50. A high concentration of cathepsin D resulted in cleavage also occurring at Phe19-Phe20, Phe20-Ala21 and Phe93-Phe94 of the C100, suggesting that these sites are somewhat less sensitive to the action of cathepsin D. Digestion of C100 using different solublizing agents indicated that the cleavage of C100 by cathepsin D is greatly influenced by the structural integrity of the substrate. However, our results suggest that cathepsin D could generate the pathogenic beta A4 amyloid peptides from its precursor in vitro, which may indicate a role in the amyloidogenesis of Alzheimer's disease.

Human rasGTPase-activating protein (human counterpart of GAP1m): sequence of the cDNA, primary structure of the protein, production and chromosomal localization.

When cDNA encoding rat rasGTPase-activating protein (rat GAP1m) was used as a probe, two partial cDNA clones of a human counterpart of rat GAP1m were isolated from a cDNA library derived from growth-arrested normal human ectocervical epithelial cells. One clone was found to be a cDNA of premature mRNA with two introns. A complete cDNA of human GAP1m was constructed by a series of reverse transcription-polymerase chain reaction (RT-PCR) using total RNA from human epidermoid carcinoma A431 cells. Human GAP1m shows 87.7% nucleotide identity to rat GAP1m in open reading frame and encodes an 850-amino acid protein that shows 89.2% identity to rat GAP1m. A 100-kDa protein was detected in A431 cells by Western blotting with anti-rat GAP1m antibody. The human GAP1m gene was mapped to chromosome 3q24-q26.

cDNA cloning and chromosomal mapping of genes encoding novel protein kinases termed PKU-alpha and PKU-beta, which have nuclear localization signal.

We have cloned cDNAs for novel serine/threonine protein kinases (PK), termed PKU-alpha and PKU-beta, by screening a bacteriophage expression library for kinase activity. Sequence analysis of PKU-alpha and PKU-beta genes revealed that their open reading frames (ORF) were 2151 and 2361 nucleotides (nt) encoding polypeptides of 717 and 787 amino acid (aa) residues, respectively. The deduced aa sequences of PKU-alpha and PKU-beta contained typical serine/threonine PK domains at the C-terminal region and were 86% identical to each other, indicating that they belong to the same PK family. Northern analysis reveals that they are expressed in nearly all human tissues and in cultured cells. The genes for PKU-alpha and PKU-beta were mapped to chromosome 17q23 and 8p12-p22, respectively, by fluorescence in situ hybridization. The proteins encoded by both cDNAs contain a putative nuclear localization signal (NLS) in their N-terminal region. These signals are likely to function in nuclear localization. Glutathione S-transferase (GST)-fusions to regions of PKU-alpha and beta containing the NLS were efficiently localized to the nucleus. In addition, PKU-beta transiently expressed in COS-1 cells was predominantly nuclear. PKU-alpha and PKU-beta differ: a consensus sequence for a nt binding motif is present near the NLS of PKU-beta. These results suggest that PKU-alpha and beta may phosphorylate serine and/or threonine residues on similar proteins, but their activities are regulated through distinct interactions with a nuclear component.

A novel cDNA clone of Schistosoma japonicum encoding the 34,000 Dalton eggshell precursor protein.

A cDNA clone encoding the 34 kDa eggshell protein of Schistosoma japonicum was isolated from an adult female cDNA library with a rabbit antiserum raised against the 34 kDa female worm fraction. A 230 bp-insert of this clone (Sj23A) was introduced in frame into the expression plasmid vector, pMAL-c2, and the recombinant fusion protein of the Sj23A transiation product was induced in Escherichia coli. The antiserum raised against the recombinant protein reacted only with the native 34 kDa protein of mature female worms, which localized in the vitelline cells of the vitelline glands. By reverse transcription-polymerase chain reaction (RT-PCR) analysis, it was found that the gene corresponding to the Sj23A was expressed exclusively in mature female worms. The clone Sj23A showed a high degree of homology to the genes for the eggshell precursor proteins of Fasciola hepatica. At the deduced polypeptide level, the Sj23A also had similarities with the F. hepatica-protein sequence, the amino acid composition [high glycine (16%), lysine (12%) and tyrosine (11%)] and the presence of tyrosine residues flanked by glycine. The clone Sj23A also shared an extensive sequence homology with 3 S. mansoni expression sequence tags (ESTs). The present results suggest that the protein encoded by the female-specific Sj23A gene of S. japonicum is widely conserved in trematodes and plays a significant role as a precursor involved in eggshell formation.

Analysis of protein expression by mammalian cell lines stably expressing lactate dehydrogenase-elevating virus ORF 5 and ORF 6 proteins.

Lactate dehydrogenase-elevating virus (LDV) has a strict species-specificity. Because only a subset of mouse primary macrophages have been identified that can support LDV replication in vitro, the precise molecular mechanism of viral entry and replication remains unclear. To analyze the LDV envelope proteins, which probably mediate viral attachment to the host cell, we developed a mammalian system for stable co-expression of LDV open reading frame (ORF) 5- and ORF 6-encoded proteins (ORF 5 and ORF 6 proteins), which correspond to envelope VP-3 and M/VP-2, respectively, and compared these expressed proteins to the native ones. Western blotting analysis combined with N-glycanase digestion revealed that ORF 5 and ORF 6 proteins were similar in size to native VP-3 and M/VP-2, and that ORF 5 protein was N-glycosylated, like the native VP-3. Immunofluorescence microscopy revealed that both ORF 5 and ORF 6 proteins were distributed throughout the cytoplasm and were colocalized in most cells. Moreover, ORF 5 protein was localized both in the perinuclear region and the Golgi complex and transported to the cell surface. This mammalian expression system in which the exogenously expressed proteins closely resemble the native proteins will provide the experimental basis for further studies of the interactions between LDV envelope proteins and host cells.

Production of virus-specific antiserum corresponding to sequences in the lactate dehydrogenase-elevating virus (LDV) ORF6 protein.

The elucidation of the antigenic structure of the envelope proteins of Arteriviridae which includes lactate dehydrogenase-elevating virus (LDV) will provide further understanding of a mechanism of strict host cell specificity. To analyze the linkage between LDV envelope proteins, M/VP-2 and VP-3, which may play an important role in viral infectivity, we generated specific antibody against M/VP-2 that has not been reported in previous studies. A synthetic polypeptide corresponding to the C-terminal region of LDV strain C (LDV-C) ORF6, which encodes M/VP-2, was chemically synthesized and coupled to keyhole limpet hemocyanin (KLH). The peptide was immunogenic in rabbits and induced antibody specific for viral protein. Western blotting and immunofluorescence analysis of virion M/VP-2 in infected macrophages showed that the antibody was able to react specifically with authentic virion protein. The immunoreactive antibody against LDV M/VP-2 described in this study will be useful for further studies of the specific roles of the envelope proteins in arterivirus assembly and infectivity.

A quantitative analysis of radiation-induced chromosome aberrations with a fluorescent digital image microscope.

Using a synthetic, alpha satellite consensus DNA unit as a probe, we could show dicentrics as well as acentric fragmented chromosomes in metaphases of gamma-irradiated lymphocyte cells and that the number of appearance of dicentrics or acentric fragments seemed to be proportional to radiation doses. To make such examination with a large number of chromosomes of metaphases, a quantitative fluorescence measurement was performed using a fluorescent microscope digital image analysis system. The relative amounts of fluoresceinated probe hybridized to alpha satellite DNA varied with chromosomes to a certain extent (1-4% of total probe-fluorescence of one metaphase). However, we could score dicentrics and acentric fragments as dots with extraordinarily higher or low percentage in plots of relative amount of probe-fluorescence on metaphase chromosome in gamma-irradiated cells. The number of appearance of acentric fragments were proportional to radiation doses of 1, 2 and 4 Gy. In the case of dicentrics, the number of appearance seemed to be proportional to square doses. Further, to reduce the variation of relative amounts of probe-fluorescence, we tried to make probe-fluorescence reflect the content of alpha satellite DNA on each chromosome more exactly, using a DNA probe amplified by polymerase chain reaction.

Characterization of Sri Lanka rabies virus isolates using nucleotide sequence analysis of nucleoprotein gene.

Thirty-four suspected rabid brain samples from 2 humans, 24 dogs, 4 cats, 2 mongooses, I jackal and I water buffalo were collected in 1995-1996 in Sri Lanka. Total RNA was extracted directly from brain suspensions and examined using a one-step reverse transcription-polymerase chain reaction (RT-PCR) for the rabies virus nucleoprotein (N) gene. Twenty-eight samples were found positive for the virus N gene by RT-PCR and also for the virus antigens by fluorescent antibody (FA) test. Rabies virus isolates obtained from different animal species in different regions of Sri Lanka were genetically homogenous. Sequences of 203 nucleotides (nt)-long RT-PCR products obtained from 16 of 27 samples were found identical. Sequences of 1350 nt of N genes of 14 RT-PCR products were determined. The Sri Lanka isolates under study formed a specific cluster that included also an earlier isolate from India but did not include the known isolates from China, Thailand, Malaysia, Israel, Iran, Oman, Saudi Arabia, Russia, Nepal, Philippines, Japan and from several other countries. These results suggest that one type of rabies virus is circulating among human, dog, cat, mongoose, jackal and water buffalo living near Colombo City and in other five remote regions in Sri Lanka.

The role of microRNA-150 as a tumor suppressor in malignant lymphoma.

MicroRNA (miRNA; miR) is a class of small regulatory RNA molecules, the aberrant expression of which can lead to the development of cancer. We recently reported that overexpression of miR-21 and/or miR-155 leads to activation of the phosphoinositide 3-kinase (PI3K)-AKT pathway in malignant lymphomas expressing CD3(-)CD56(+) natural killer (NK) cell antigen. Through expression analysis, we show in this study that in both NK/T-cell lymphoma lines and samples of primary lymphoma, levels of miR-150 expression are significantly lower than in normal NK cells. To examine its role in lymphomagenesis, we transduced miR-150 into NK/T-cell lymphoma cells, which increased the incidence of apoptosis and reduced cell proliferation. Moreover, the miR-150 transductants appeared senescent and showed lower telomerase activity, resulting in shortened telomeric DNA. We also found that miR-150 directly downregulated expression of DKC1 and AKT2, reduced levels of phosphorylated AKT(ser473/4) and increased levels of tumor suppressors such as Bim and p53. Collectively, these results suggest that miR-150 functions as a tumor suppressor, and that its aberrant downregulation induces continuous activation of the PI3K-AKT pathway, leading to telomerase activation and immortalization of cancer cells. These findings provide new insight into the pathogenesis of malignant lymphoma.

A simple, sensitive high-performance liquid chromatography -ultraviolet method for the quantification of concentration and steady-state pharmacokinetics of itraconazole and hydroxyitraconazole.

BACKGROUND: A steady-state trough plasma itraconazole concentration greater than 500 ng/mL is a therapeutic target for itraconazole. A simple, rapid and sensitive high-performance liquid chromatography-based method was developed for quantitation of itraconazole and hydroxyitraconazole in human plasma. METHODS: Itraconazole and hydroxyitraconazole were separated using a mobile phase of 0.5% KH2PO4 (pH 6.0)-acetonitrile (30:70, v/v) on a CAPCELLPAK C18 MGII column at a flow rate of 0.5 mL/min and ultraviolet absorbance at 260 nm. RESULTS: The analysis required 200 microL of plasma and involved a rapid, simple solid-phase extraction with an Oasis HLB cartridge, which resulted in recoveries of 87-92% for itraconazole and 91-94% for hydroxyitraconazole. The lower limit of quantification for itraconazole and hydroxyitraconazole was 5 ng/mL each. Intra- and interday coefficients of variation for itraconazole and hydroxyitraconazole were less than 11.3% and 12.2%, respectively, and accuracies were within 11.7% and 4.5% over the linear range, respectively. Although the steady-state plasma concentrations of itraconazole and hydroxyitraconazole ranged from 506 to 2482 ng/mL and from 766 to 2444 ng/mL, respectively, after a two-day loading dose of 400 mg/day intravenous itraconazole followed by the administration of 200 mg/day itraconazole oral solution, calibration curves of itraconazole and hydroxyitraconazole showed positive linearity in a concentration range of 5-2500 and 50-2500 ng/mL, respectively. CONCLUSIONS: Our results indicate that this method is applicable for the monitoring of plasma levels of itraconazole and hydroxyitraconazole in a clinical setting. Furthermore, the regimen presented here might also be effective in preventing infection, but further studies with large sample sizes are necessary to investigate this avenue.

Application of synthetic DNA probes of human alpha satellite consensus monomer for detection of centromere-involved chromosome abnormalities.

We have synthesized the alphoid monomer of 171 bp based on the consensus sequence of human alpha satellite DNA and constructed a clone of dimeric or tetrameric sequence unit. Southern blot analysis using the clone as a probe showed restriction site periodicities in human DNA digested by EcoRI or BamHI. The synthetic consensus unit could detect the alpha repeated centromeric regions of all human chromosomes by fluorescence in situ hybridization. Using the cells having a dicentric X chromosome, we showed that the two centromeric regions were stained with fluorescent alpha satellite DNA probes. Thus the probe would be useful to detect chromosomal abnormalities such as dicentrics.

Isolation of a mammalian cell cycle ts mutant, tsJT663, defective in preparation for passing restriction point.

A cell cycle ts mutant, tsJT663, isolated from Fischer rat cell line 3Y1, was characterized. The execution point of tsJT663 was approximately 2 h before S phase, starting either from a G0 (quiescent) state or from the previous cell cycle. Progression of the cell cycle other than from G0/G1 to S phase was temperature insensitive. The restriction (R) point was also estimated as about 2 h before S phase. When tsJT663 cells at log phase were transferred to 40 degrees C, the cell number increased and then decreased within 2 days and thereafter the cells were growth arrested stably for more than 4 weeks. When the serum-stimulated cells were cultured at 34 degrees C for 6 h at 40 degrees C for various period of time and then at 34 degrees C up to the end of the experiments at 30 h, the frequency of cells entering S phase declined depending upon the duration of culture at 40 degrees C. Assuming that the decline of the frequency of tsJT663 cells capable of entering S phase corresponded to the decline of a putative material required for cells to pass the R point toward S phase, the half-life of this material at 40 degrees C was 1 h. These results are consistent with a tentative conclusion that tsJT663 is a cell cycle ts mutant which does not prepare at nonpermissive temperature for passing the restriction point toward S phase.