Proliferation of Hepatocytes and Attenuation from Carbon Tetrachloride Hepatotoxicity by Gadolinium Chloride in Rats

Abstract: Intravenous injection of gadolinium chloride (GdCl₃) at a dose of 10 mg/kg caused an increase in proliferating cell nuclear antigen labeling index and the grade of pyronin positivity (RNA level) in rat liver. In CCl₄-exposed rats, pretreatment with GdCl₃ also showed a preventive effect of the liver injury both biochemically and histologically. Moreover, the proliferative action preceded the attenuative effect of the liver injury. Results suggest that GdCl₃ induces hepatocyte proliferation, and this action of GdCl₃ may modify the development of CCl₄-induced liver injury.     

In Vivo Molecular Imaging Characterizes Pulmonary Gene Expression During Experimental Lung Transplantation

Experimental gene therapy is a promising strategy to prevent ischemia-reperfusion (I/R) injury and allograft rejection after lung transplantation, and methods will eventually be needed to characterize pulmonary transgene expression in vivo in humans. Therefore, we studied positron emission tomography (PET) as a means of performing in vivo molecular imaging in rodent models of lung transplantation. Rats were transfected endotracheally with adenovirus encoding a fusion gene of a mutant Herpes simplex virus-1 thymidine kinase and the green fluorescent protein gene (the former serving as an imaging reporter gene). Twenty-four hours after transfection, lungs were transplanted in groups representing normal transplantation, I/R injury and acute allograft rejection. Imaging was obtained either 24 h after transplantation to study reperfusion injury or 4 days after transplantation to study graft rejection. After imaging, lungs were excised and analyzed for thymidine kinase activity. Imaging detected transgene expression in transplanted lungs even in the presence of acute rejection or I/R injury. The PET imaging signal correlated with in vitro lung tissue assays of thymidine kinase activity (r(2) = 0.534). Thus, noninvasive molecular imaging with PET is a feasible, sensitive and quantitative method for characterizing pulmonary transgene expression in experimental lung transplantation.     

Plasma and tumor gastrin in patients with primary hyperparathyroidism

It is well known that primary hyperparathyroidism is often associated with peptic ulcer. The purpose of this study is to confirm the relationship between the gastrin-levels before and after parathyroidectomy in fourteen patients with primary hyperparathyroidism, and to determine the localization of gastrin in the surgically resected parathyroid tumor. The results obtained were as follows: 1) Three patients had peptic ulcer (gastric ulcer and duodenal ulcer), the incidence being 21%. 2) The basal serum gastrin levels were 123.0% +/- 68.1 pg/ml before operation and decreased to 90.2 +/- 44.5 pg/ml after operation. In the 3 patients with slightly elevated gastrin levels, the mean level before operation was 209.1 +/- 61.2 pg/ml. The gastrin level decreased to 116.4 +/- 62.0 pg/ml after operation. 3) Gastrin immunoreactivity was detected in 10 out of 14 tumors and its localization was at the periphery of tumor cells. From these results, we conclude that extragastric gastrin secretion from parathyroid tumors may be one of the cause of peptic ulcer in patients with primary hyperparathyroidism.     

Effects of preoperative transcatheter portal embolization (TPE) on prevention of hepatic failure after massive hepatectomy]

Effects of TPE on prevention of hepatic failure after massive hepatectomy were studied experimentally using dogs. A 70% or 85% hepatectomy (Hx) was performed two weeks after TPE. All of the 70%Hx groups with(+)/without(-) TPE were alive for over two weeks after hepatectomy. While all of the 85%Hx group without TPE died, eight of ten in the 85%Hx group with TPE survived. Without TPE, total bilirubin levels in sera were elevated markedly in the 85%Hx group and moderately in the 70%Hx group after hepatectomy. The levels of escaped enzymes in sera, such as GOT or GPT, were also elevated remarkably in the TPE(-) groups. Although the levels of these enzymes were also high in the 85%Hx.TPE(+) group, these values were as same as those of 70%Hx.TPE(-) group. In the 85%Hx.TPE(-) group, critical diminution of functional hepatic cell mass and severe portal hypertension occurred after hepatectomy and coagulopathy and death followed to these phenomena. TPE might prevent the onset of these critical phenomena, and diminish the damage caused by massive hepatectomy. These results suggest that TPE is useful for prevention of postoperative hepatic failure so that we could perform massive hepatectomy safely, and extend the operative indication.     

Clinical results of staged repair with complete unifocalization for pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries.

OBJECTIVE: Our treatment strategy for pulmonary atresia with ventricular septal defect (VSD) and major aortopulmonary collateral arteries is a staged repair that comprises the first complete unifocalization (UF) with 'unification' of intrapulmonary arteries and then the definitive repair. The purpose of this study is to evaluate the outcome of our staged repair strategy with complete UF and to determine the results of our current management strategy. METHODS: From 1982 to 2004, 113 consecutive patients were treated with staged repair at our institute. We evaluated the risk of definitive repair failure or death in the 3 years after definitive repair using logistic regression. Furthermore, we compared the early group (patients who underwent UF before December 1995) and the late group (patients who underwent UF after January 1996). RESULTS: The mean follow-up interval was 8.8 years (0.8 months to 23.3 years), and Kaplan-Meier-estimated overall survival rates after first UF were 80.9, 73.8, and 69.9% at 5, 10, and 15 years, respectively. Survival in patients with an absent central pulmonary artery (PA) was significantly lower than in those with a central PA (p<0.05), and the factor that was significantly associated with definitive repair failure or death in the 3 years after definitive repair was central PA morphology (p<0.05). Higher mean PA pressure after UF was detected in patients with hypoplastic central PA, compared with those without hypoplastic PA (30.9 mmHg vs 23.3 mmHg, p<0.05). In the late group, age (in years) at first UF (3.9 vs 8.4, p<0.01), second UF (4.3 vs 9.2, p<0.01), and definitive repair (5.8 vs 9.1, p<0.01) was significantly younger than in early group, and the survival rate after first UF in the late group was 96.2 and 91.3% at 3 and 7 years, respectively. Systolic right ventricular pressure and the pressure ratio between the right and the left ventricles after definitive repair in the late group were significantly lower than in the early group (53.6 mmHg vs 75.0 mmHg, p<0.01; 61.7% vs 75.9%, p<0.05). CONCLUSIONS: Hypoplastic central PA was a significant risk factor in this disease. The overall survival was improved by our current management strategy. Improved RV pressure after definitive repair appears to affect the long-term outcome.     

Equivalent current dipole estimated from SSR potential distribution over the human hand. Sympathetic skin response.

OBJECTIVE: We aimed to determine whether or not the potential distribution of the sympathetic skin response (SSR) on the palm and dorsum of the hand can be described by an equivalent current dipole (ECD) as an SSR source model. METHODS: The SSR of 22 normal subjects were simultaneously obtained from two electrodes placed on the palm and the dorsum of hand, with an indifferent electrode on the thumbnail. We then measured the SSR potential distribution in 10 of the 20 subjects who had responded to stimulation with a clear dorsal SSR. To do this, 18 electrodes were attached to the palm and dorsum of the hand. SSR-evoking stimulation (sound, voice and rapid inspiration) were randomly delivered to the subject at time intervals of more than 1min to minimize the habituation effect. We estimated the ECD from the measured potential distribution. RESULTS AND CONCLUSIONS: The SSR-evoked by stimulation was negative in potential at the palmar sites of all 22 subjects, and was positive in potential at the dorsal sites of the hand in 20 of the 22 subjects. The SSR potential distribution, which was measured in 10 subjects, reached its maximum negative and positive potential near the base of the middle finger on the palm, and near the corresponding site on the dorsum of the hand, respectively. The SSR potential measured on the dorsum of the hand, however, was about 1/3 in amplitude of those on the palmar sites. These results suggest that the SSR source is located on the palm (probably the sweat glands) as confirmed by the estimated ECD (a negative pole on the palm and a positive pole on the dorsum of the hand). We speculate that the SSR may result from the potential difference caused by the Na(+) concentration gradient in the sweat, which results from intracanal reabsorption of Na(+). SIGNIFICANCE: The ECD resulting from the Na(+) concentration gradient within the canal of sweat glands is thought to be the source of the SSR from the negative pole on the palm to the positive pole on the dorsum.     

Osteosarcoma. Ultrastructural and immunohistochemical studies on alkaline phosphatase-positive tumor cells constituting a variety of histologic types

The osteosarcomas were subclassified into osteoblastic, fibroblastic, chondroblastic and telangiectatic types and examined by electron microscopy. Their immunohistochemical reactions were also studied. In an overall survey of the above types, fibroblast-like cells revealed poorly developed cytoplasmic organelles with rather short, branching rough endoplasmic reticulum, mixed with osteoblast-like cells that were hardly distinguishable from the former. They appeared to be an early stage of an osteoblastic cell lineage from the distribution and development of their cell organelles and highly positive vimentin activity. The tumor cells in malignant cartilage varied in appearance from chondroblast-like to osteoblast-like cells. All types of tumor cells expressed alkaline phosphatase activity to a significant degree. Immunohistochemical staining showed a mixture of procollagen type I-positive cells among the cells positive for both procollagen type II and S-100 protein in the malignant cartilage. Irrespective of any ultrastructural differences between these various tumor cell types, they all revealed a significant degree of ALPase activity unlike other types of bone tumors, suggesting that the tumor cells which constitute the various types of osteosarcoma are derived from a common precursor cell.     

CDK4 is a probable target gene in a novel amplicon at 12q13.3-q14.1 in lung cancer

Several chromosomal regions are recurrently amplified or deleted in lung tumors, but little is known about the underlying genes, which could be important mediators in tumor formation or progression. In lung cancer, the RB1-CCND1-CDKN2A pathway, involved in the G1-S transition, is damaged in nearly all tumors. In the present study, we localized a novel amplicon in lung tumors to a fragment of less than 0.5 Mb at 12q13.3-q14.1 by using comparative genomic hybridization (CGH) on cDNA microarrays. This approach enabled us to identify 10-15 genes with the most consistent amplifications. Semiquantitative RT-PCR analyses of 13 genes in this region showed that four of them (CDK4, CYP27B1, METTL1, and TSFM) were also highly up-regulated. Immunohistochemical (IHC) analysis of 141 tumor samples on a tissue microarray showed that CDK4 was expressed at a high level in 23% of lung tumors. Six (21.4%) of the tumors with high CDK4 expression (n = 28) were shown by fluorescence in situ hybridization (FISH) to contain the 12q13.3-q14.1 amplification. For CDK4, a positive correlation was found between gene copy number (FISH and CGH array), mRNA expression (RT-PCR), and level of protein expression (IHC). CDK4 expression did not correlate with CDKN2A methylation status. Amplification of CDK4 has been described in other tumor types, but its role in lung cancer remains to be elucidated. Although CDK4 amplification seems to be a relatively rare event (4.3%) in lung tumors, it indicates the significance of the RB1-CCND1 pathway in lung tumorigenesis.     

Dual-probe assay for rapid detection of drug-resistant Mycobacterium tuberculosis by real-time PCR

Mutations in particular nucleotides of genes coding for drug targets or drug-converting enzymes lead to drug resistance in Mycobacterium tuberculosis. For rapid detection of drug-resistant M. tuberculosis in clinical specimens, a simple and applicable method is needed. Eight TaqMan minor groove binder (MGB) probes, which discriminate one-base mismatches, were designed (dual-probe assay with four reaction tubes). The target of six MGB probes was the rpoB gene, which is involved in rifampin resistance; five probes were designed to detect for mutation sites within an 81-bp hot spot of the rpoB gene, and one probe was designed as a tuberculosis (TB) control outside the rpoB gene hot-spot. We also designed probes to examine codon 315 of katG and codon 306 of embB for mutations associated with resistance to isoniazid and ethambutol, respectively. Our system was M. tuberculosis complex specific, because neither nontuberculous mycobacteria nor bacteria other than mycobacteria reacted with the system. Detection limits in direct and preamplified analyses were 250 and 10 fg of genomic DNA, respectively. The system could detect mutations of the rpoB, katG, and embB genes in DNAs extracted from 45 laboratory strains and from sputum samples of 27 patients with pulmonary TB. This system was much faster (3 h from DNA preparation) than conventional drug susceptibility testing (3 weeks). Results from the dual-MGB-probe assay were consistent with DNA sequencing. Because the dual-probe assay system is simple, rapid, and accurate, it can be applied to detect drug-resistant M. tuberculosis in clinical laboratories.