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.     

Effects of Zinc on Production of Active Oxygen Species by Rat Neutrophils

Abstract: The effects of zinc on the production of active oxygen species were investigated in rat neutrophils by chemilumi-nescence and spectrophotometric assays. The luminol-dependent chemiluminescence in unstimulated neutrophils showed a single peak. Zinc at concentrations lower than 0.1 mM augmented the intensity of chemiluminescence and showed a bimodal pattern, the first peak of which was inhibited by superoxide dismutase and catalase, while the second peak disappeared in the presence of catalase, but was unaffected by superoxide dismutase. At the same concentrations of zinc, O₂^? and H₂O₂ production increased, but secretion and activity of myeloperoxidase were not affected. Zinc at 0.1 mM enhanced the second peak of luminol-dependent chemiluminescence, and concomitantly O₂^? and H₂O₂ production of neutrophils stimulated with formyl-methionyl-leucyl-phenylalanine. Homogenized neutrophils showed a bimodal pattern on induction by zinc, the second peak of which was inhibited slightly by catalase and completely by sodium azide, but was not inhibited by superoxide dismutase. Zinc-induced O₂^? production was inhibited by pertussis toxin, but was not significantly inhibited by a protein kinase C inhibitor, 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H-7), or a calmodulin antagonist, N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7). These results suggest that zinc can augment luminol-dependent chemiluminescence by increasing O₂^? production through the classical signal transduction pathway, and by increasing H₂O₂ not via O₂^?.     

Human parvovirus-induced transient anemia and leukopenia after delivery]

A 30-year-old female at 27 weeks' gestation, was hospitalized on September 24 1990 because of the premature rupture of the amniotic sac. She underwent Caesarean section on the same day with 700 ml blood loss, but no blood transfusion was required. For several days after the operation, her hemoglobin level remained 7.8 g/dl and did not increase significantly in spite of parenteral iron therapy. On the 9th postoperative day, chills and pyrexia developed with leukopenia. Bone-marrow aspiration revealed severe erythroblastopenia with giant proerythroblasts, suggesting recent HPV infection, which was confirmed by the presence of anti-HPV IgM and HPV antigen by ELISA. The hemoglobin level gradually decreased to 6.0 g/dl by the 21st day, then began to increase rapidly. The serum of acute-phase containing HPV antigens inhibited BFU-E and CFU-E but not CFU-GM. The serum of convalescent-phase inhibited neither erythroid colony growth nor myeloid colony growth. These results indicate that the inhibitory effect of HPV in colony assay is highly specific for erythropoiesis and that HPV play a role in transient cessation of erythropoiesis. The reason, however, for leukopenia in HPV infection remained unclear. This case shows that HPV infection may induce severe hematological disorders even in normal person under erythropoietic stress.     

Transferrin receptor distribution and iron deposition in the hepatic fobufe of iron-overloaded rats

Under the condition of obvious iron-overload, there is a zonal hernoeiderin (iron) deposition in hepatic lobules. The deposition is heavtest in the periporfal (zone 1) and lightest in the perivenws (zone 3) hepatocytes. However, the mechanism for this pattern of iron deposition is obscure. Hepatic tissues from control, iron-deficlent or ironoverloaded Wistar rats me used to study its pathogenesis. iron-deficiency was Induced by a low Iron regimen. Ironoverload was produced by repeated intraperitoneal injections of ferric nitrilotriace-We (Fe³⁺-NTA) for 1–4 months. Liver tissues of the rats were lmmunohistochemically and histochemically stained for tmnaferrin receptor (TfR), transferrin (Tf), ferritin (Ft), and iron. The staining intensity of TfR, Tf and Ft increased in hepatocytes of iron-deflctent rats and decreased in that of the iromverloaded in comparison with the control rats. TfR atalning was strong in zone 1, with gradual transition into weak staining in zone 3 hepatocytes of the rat liver. TfR located primarily on the hepatocyte membrane. Tf had both membranous and cytoplasmic distribution. Many hepatocytes in group B had strong cytoplasmic Tf staining. Conversely, only a few hepatocytes had weakly stained cytoplasmic Tf in group C. Hepatocytes and Kupffer cells were Ft positive in control rats. Ft was distributed only in the cytoplasm. The staining intensity of Ft was stronger in zone 3 than in zone 1 hepatocytes of iron-deficient rats. In iron-overloaded rats, the iron deposition was severe in zone 1 and mild in zone 3 hepatocytes. These findings suggest that uptake of iron into hepatocytes in vivo is regulated and mediated by TfR and Tf. Gradient TfR distribution from zone 1 to 3 hepatocytes and active TfR-Tf mediated iron uptake resuited in the zonal iron deposition in the hepatic lobule of iron-overloaded rats.     

A case of esophageal cancer with an aberrant right subclavian artery treated with mediastinoscopic esophagectomy

An aberrant right subclavian artery (ARSA) is one of the famous anatomical abnormalities with a prevalence of 0.16–4.4%. In esophagectomy, anatomical abnormalities of the ARSA could cause complications with some surgical procedures. An 85-year old man was referred to our department for esophageal adenocarcinoma that was at a slightly high position for esophagectomy with the abdominal approach. However, he had a significant past medical history. This risk factor made it difficult to perform thoracoscopic esophagectomy. He underwent mediastinoscopic esophagectomy (ME) with the left cervical and laparoscopic approach. The ARSA presented no difficulties with the ME surgical technique including the dissection of the left recurrent laryngeal nerve lymph node. Although this patient had a respiratory dysfunction and some difficulties in a prone position, ME enabled a safe esophagectomy with lymph node dissection.     

The effects of caregiving resources on the incidence of depression over one year in family caregivers of disabled elderly

The purpose of the study was to investigate the over-time effects of physical, psychological and social resources on the incidence of depression in family caregivers of the disabled elderly. Data were collected twice at a one-year interval from 1,141 primary caregivers of a disabled older person in an urban area of Japan using a self-reported questionnaire survey. The questionnaire included physical health as an indicator of physical resources, caregiving satisfaction and intention to care as indicators of psychological resources, and instrumental and emotional support network and formal home care service utilization as indicators of social resources. The mental health outcome measure was the General Health Questionnaire 12-item version (GHQ-12). Complete data on 235 non-depressed female caregivers were separated into 3 groups according to the relationship type (wife, daughter and daughter-in-law) and analyzed separately. Multivariate logistic regression models controlling for duration of caregiving, care-recipient's gender, ADL dependency and behavioral problems demonstrated that significant predictors of depression were caregiving satisfaction and intention to care in wives, caregiving satisfaction in daughters, and physical health and emotional support network in daughters-in-law. Noteworthy, intention to care increased the risk of depression in wives, while decreasing the risk of depression in daughters-in-law. The findings indicate that the effects of caregivers' resources on mental health may differ by relationship type.     

Lack of Direct Involvement of 8-Hydroxy-2'-deoxyguanosine in Hypoxanthine-guanine Phosphoribosyltransferase Mutagenesis in V79 Cells Treated with N,N'-Bis(2-hydroxyperoxy-2-methoxyethyl)-l,4,5,8-naphthalenetetracarboxylic-diimide (NP-III) or Riboflavin

The object of this study is to investigate the relationship between a typical product of oxidative DNA damage, 8-hydroxy-2'-deoxyguanosine (8OHdG), and mutagenesis in V79 cells through a molecular analysis of hypoxanthine-guanine phosphoribosyltransferase ( hprt ) gene mutants. We performed a direct sequencing analysis of the cDNA of mutants obtained after treatment with N,N'-bis(2-hydroxyperoxy-2-methoxyethyl)-l,4,5,8-naphthalenetetracarboxylic-diimide (NP-III) or riboflavin, each of which induces the formation of 8OHdG in cellular DNA upon UVA irradiation. The frequency of mutation after both treatments was no more than 2 to 5 times the control value. A considerable number of the mutants could not be amplified by RT-PCR, and this was also the case for the control mutants. Among the mutants analyzed, deletions and a TA→Ã transversion occurred predominantly. The reasons for the weak association of induction of 8OHdG with frequency of mutation and the possible mechanism of oxidative-stress-derived mutagenesis are discussed.