Reactivation of feline foamy virus from a chronically infected feline renal cell line by trichostatin A.

Although acute infection of feline foamy virus (FeFV) is normally highly cytopathogenic in Crandell feline kidney (CRFK) cells, a noncytopathic persistent infection was established in the cells after cocultivation of the initially infected cells with uninfected cells four times. To investigate reactivation of persistent infection, CRFK cells chronically infected with FeFV were treated with trichostatin A (TA), a histone deacetylase inhibitor. TA induced higher FeFV production from the Coleman strain carrier culture and also induced marked syncytium formation. In contrast, human foamy virus, which contains less homologous long terminal repeat (LTR) and putative internal promoter (IP) sequences, persistently infecting baby hamster kidney cells was not reactivated by TA. The Sammy-1 strain of FeFV, from which a part of the U3 region in the LTR is naturally deleted, showed less reactivation. The Coleman LTR promoter-based beta-Gal-expressing plasmid was activated in the persistently Coleman-infected cells in the presence of TA, whereas the Sammy-1 LTR was not activated. Furthermore, the amounts of Gag protein expressed did not change in the presence or absence of TA. Because the putative IP region was very similar between the two strains, the initiation by TA is relatively specific for LTR sequences, and, therefore, histone deacetylation is at least in part responsible for reactivation of FeFV from carrier cell culture.

Identification and DNA sequence analysis of the Marek's disease virus serotype 2 genes homologous to the herpes simplex virus type 1 UL20 and UL21.

We determined 3,135 bp of the nucleotide sequence located in an 8.5 kb EcoRI-E fragment in the unique long (UL) genome region of Marek's disease virus serotype 2 (MDV2), and identified UL20 and UL21 homologous genes of herpes simplex virus type 1 (HSV-1). The UL20 and UL21 homologous genes of MDV2 are arranged colinearly with the prototype sequence of HSV-1. In addition, an open reading frame (MDV2 ORF 273), which has been identified within the UL21 homologous gene of MDV2, has no apparent relation to any other known herpesvirus genes. Northern blot analysis and reverse transcriptase polymerase chain reaction confirmed the existance of RNA transcripts related to the UL20 and ORF 273 genes in MDV2-infected cells, except no transcript related to the UL21 gene being detected. The putative protein product of the MDV2 UL20 gene had a relatively low homology but that of the MDV2 UL21 gene had a moderate homology among herpesviruses. Further, the possible functions and features of the predicted proteins encoded within the sequenced region are discussed.

New quantitative methods for detection of feline parvovirus (FPV) and virus neutralizing antibody against FPV using a feline T lymphoid cell line.

Previously, we reported that a feline T lymphoid cell line, FL74 cells, was very sensitive to feline parvovirus (FPV) infection. In the present study, we developed new quantitative methods for detection of FPV and virus neutralizing antibody against FPV using FL74 cells. The methods presented here were very simple and applicable to both canine parvovirus and feline panleukopenia virus.

A case of microscopic polyarteritis nodosa with interstitial pneumonia successfully treated with steroid pulse therapy and immunosuppressive agents.

We report a patient with microscopic polyarteritis nodosa (mPN) and interstitial pneumonia, who was subjected to investigation by bronchoalveolar lavage (BAL), thoracic computerized tomography (CT) and gallium-67 citrate (67Ga) scintigraphy before and after administration of glucocorticoid and immunosuppressive agents. Renal function, renal histology, interstitial inflammation of the lung, and pulmonary function and histology improved cytoplasmic autoantibody (MPO-ANCA), which decreased with decreasing disease activity after starting treatment. Interstitial pneumonia may be associated with pulmonary capillaritis due to mPN. Methylprednisolone pulse therapy followed by oral prednisolone and immunosuppressive agents is considered to be an effective therapeutic strategy for combined mPN and interstitial pneumonia.

Thrombotic thrombocytopenic purpura accompanied by transient pure red cell aplasia and thymoma.

We describe a 64-year-old man with thrombotic thrombocytopenic purpura (TTP), transient pure red cell aplasia (PRCA) and thymoma. TTP in this case was thought to be idiopathic and was accompanied by microangiopathic hemolytic anemia. The patient, therefore, had an aplastic crisis due to PRCA. He was treated with peritoneal dialysis, plasma exchange with plasma infusion, red blood cell transfusion, methylprednisolone pulse therapy followed by maintenance dosing with intravenous prednisolone, gamma-globulin, vincristine, and dipyridamol. As a result, the patient's mental disorder, acute renal failure, anemia and thrombocytopenia improved; however, the haptoglobin level remained low. The pathogenesis of PRCA and thymoma indicates that these are immunological disorders often associated with each other. To our knowledge, there are no reports of TTP with transient PRCA and thymoma. Although such a combination is considered relatively rare, this case suggests that there is an immunological contribution to the pathogenesis of the association of these disorders.

[Study on serial changes in blood pressure, obesity and blood chemistry and cardiovascular disease in the long-term hospitalized patients with sequela of acute carbon monoxide poisoning].

The arteriosclerotic diseases and their risk factors were retrospectively investigated in 44 patients with chronic state of acute carbon monoxide intoxication who had been admitted since November 1963. The lack of elevations of systolic and diastolic blood pressure, serum cholesterol, fasting blood glucose and obesity index with advancing age was shown in these patients. During the observation period (mean 23.3 years), cardiovascular diseases developed in three patients, (brain hemorrhage, brain infarction, and myocardial infarction in each) but none of the patients died from such diseases. Therefore, the morbidity and mortality of arteriosclerotic diseases were less frequent than those reported in the community population. This observation seems to be attributable to the dietary and environmental control of risk factors during the long-term hospitalization. On the other hand, total protein, hematocrit, cardiothoracic ratio and calcification of the aorta on the chest X-ray, echocardiographic findings, plasma renin activity and plasma aldosterone concentration at the final examination in 1993 were similar to those seen in the community population. These findings indicate that long-term control of risk factors by hospitalization results in the lack of blood pressure increase with age and less prevalence of arteriosclerotic diseases.

[Idiopathic chronic tubulointerstitial nephritis].

Chronic tubulointerstitial nephritis is a chronic disorder that primarily affects the renal tubules and interstitium while sparing the glomeruli and vasculature. Although there are variable underlying causes, 10% to 25% of the cases of chronic tubulointerstitial nephritis are entirely idiopathic. A thorough search for the underlying causes of chronic tubulointerstitial nephritis is especially important because to avoid or to correct such underlying causes may prevent progression or even allow for some reversal of renal failure. Thus, diagnosis of idiopathic form of chronic tubulointerstitial nephritis is carefully made after the exclusion of potential underlying causes. The major pathologic features of idiopathic chronic tubulointerstitial nephritis are 1) interstitial fibrosis, 2) tubular atrophy and 3) infiltration of the parenchyma with mononuclear inflammatory cells. Of these three features, the extent of interstitial fibrosis is significantly correlated with decreased glomerular filtration rate and progression rate of renal failure. Idiopathic chronic tubulointerstitial nephritis seems to be slowly progressive and develop to end stage renal failure. Since there is no specific treatment for idiopathic chronic tubulointerstitial nephritis, avoidance and correction of exacerbation factors are essential for progression to renal failure. It is acceptable that protein-restricted diet be applied to idiopathic chronic tubulointerstitial nephritis although its effects on the disease still remain equivocal.

Lack of blood pressure increase with age in long-term hospitalised patients with the sequelae of acute carbon monoxide poisoning.

We investigated retrospectively age-related changes in BP and body composition in 44 men who had been hospitalised for up to 26 yrs as a result of carbon monoxide poisoning. The average age of the patients was 42.5 +/- 9.1 (SD) yrs on the first admission. The average period of hospitalisation was 19.5 +/- 5.9 yrs. The patients received mild salt restriction and daily exercise in the hospital. During the study period, nine patients developed hypertension and received antihypertensive treatment. The prevalence of hypertension in our study population was 205 per 1,000 and the incidence of hypertension (DBP > 95 mmHg) was 9.1 per 100 person years. Both prevalence and incidence appear to be lower than those in the general population. In the other 35 patients BP significantly decreased from 127.5 +/- 10.0 mmHg (SBP)/79.8 +/- 8.1 mmHg (DBP) at the time of the first examination to 120.8 +/- 16.3 mmHg/71.9 +/- 10.3 mmHg on the last examination. Body mass index did not change significantly during the study period. Hypertensive cardiovascular death was not observed throughout the study period. In conclusion, controlled diet, salt intake, physical exercise and isolation from the social stimuli achieved by a long-term hospitalisation may prevent increased BP and cardiovascular death.

Penile gangrene in a patient with diabetic nephropathy on continuous ambulatory peritoneal dialysis.

We report here a case of penile gangrene in a patient with diabetic nephropathy treated by continuous ambulatory peritoneal dialysis (CAPD). The patient demonstrated severe systemic arteriosclerosis. The main cause of the gangrene was considered to be circulatory insufficiency induced by severe arteriosclerosis. Several predisposing factors including chronic renal failure, long-term diabetes mellitus and CAPD-related metabolic changes such as abnormalities of lipid metabolism also appeared to have contributed to the arteriosclerotic changes. The prognosis in cases of this type is thought to be extremely poor.