Pathologic and immunohistochemical studies of Newcastle disease (ND) in broiler chickens vaccinated with ND: severe nonpurulent encephalitis and necrotizing pancreatitis.

Twenty-five 22- to 46-day-old broilers with Newcastle disease (ND) were investigated pathologically and immunohistochemically in order to evaluate the mechanism of ND outbreak in vaccinated broilers. The broilers were vaccinated with ND live vaccine via drinking water. Clinical signs were neurologic and respiratory in nature. Macroscopically, bursal atrophy, white spots on the pancreas, and discoloration and enlargement of kidneys and spleen were observed in the broilers. Histologically, perivascular cuffing, neuronal degeneration and necrosis, and glial proliferation were present in the cerebrum, cerebellum, and medulla oblongata. There was extensive rarefaction and malacia in the parenchyma of severely affected brains. There were extensive degeneration, necrosis, and depletion of acinar cells in the pancreas. There was proliferation of macrophages in the lungs with congestion, tubulointerstitial nephritis, hepatocytic necrosis with thrombi in the sinusoids, and lymphocytic depletion in the cloacal bursa. Immunohistochemically, ND virus antigens were detected in the lesions. ND virus isolated from the present cases did not cause encephalitis or pancreatitis in specific-pathogen-free chickens, but it induced mortality with hepatocytic sinusoidal thrombi, splenic necrosis, lymphoid necrosis and depletion, and conjunctival hemorrhage. Severe nonpurulent encephalitis with extensive rarefaction and malacia, and necrotizing pancreatitis in the present case may suggest a close possibly causal relation with vaccination.

Identification and functional analysis of mutations in the hepatocyte nuclear factor-1alpha gene in anti-islet autoantibody-negative Japanese patients with type 1 diabetes.

Mutations in the hepatocyte nuclear factor-1alpha (HNF-1alpha) gene are the cause of maturity-onset diabetes of the young type 3 (MODY 3), which is characterized by a severe impairment of insulin secretion and early onset of the disease. Although the majority of patients with type 1 diabetes have type 1A, immune-mediated diabetes, there is a significant percentage of the patients who have no evidence of an autoimmune disorder at the onset of disease. The aim of this study was to estimate the prevalence of MODY 3 in antiislet autoantibody negative patients with type 1 diabetes. From a large population-based sample of unrelated Japanese patients with type 1 diabetes, 28 patients who lacked autoantibodies to glutamic acid decarboxylase, islet cell antigen 512/insulinoma-associated antigen-2, phogrin (phosphate homolog of granules of insulinoma)/insulinoma-associated antigen-2beta, and insulin at the onset of type 1 diabetes were examined by PCR-based direct sequencing of the 10 exons, flanking introns, and the promoter region of the HNF-1alpha gene. Two (7.1%) of 28 autoantibody-negative patients with type 1 diabetes were identified as carrying mutations in the HNF-1alpha gene. One patient carried a frameshift mutation (Pro379fsdelCT) in exon 6, and another patient carried a novel 2-bp substitution at nucleotides +45 (G to A) and +46 (C to A) from the transcriptional site of the promoter region. These mutations were identified in heterozygous form and were not identified in 64 unrelated healthy control subjects or 54 unrelated islet autoantibody-positive patients with type 1 diabetes. Functional analysis of the mutant HNF-1alpha gene indicated that the Pro379fsdelCT mutation had no transcriptional trans-activation activity and acted in a dominant negative manner. The +45/46 GC to AA mutation in the promoter region showed reduced promoter activity by 10-20% compared to the wild-type sequence. In conclusion, about 7% of Japanese diabetic patients lacking antiislet autoantibodies initially classified as having type 1 diabetes could have diabetes caused by mutations in the HNF-1alpha gene.

Thermostable beta-galactosidase from an extreme thermophile, Thermus sp. A4: enzyme purification and characterization, and gene cloning and sequencing.

We purified and characterized a thermophilic beta-galactosidase from Thermus sp. A4 isolated from the Atagawa hot spring (Shizuoka, Japan). The enzyme was monomeric, and its molecular mass was estimated to be 75 kDa by SDS-polyacrylamide gel electrophoresis. The enzyme was extremely thermostable and retained its full activity after incubation at 70 degrees C for 20 h. The Km observed were 5.9 mM for ortho-nitrophenyl beta-D-galactopyranoside and 19 mM for lactose. We cloned and analyzed the complete sequence of the gene encoding this enzyme. It was found to consist of 645 amino acid residues. We propose that this enzyme and seven other unclassified beta-galactosidases are new members of family 42 of the glycosyl hydrolases.

Endoscopic treatment of submucosal invasive colorectal carcinoma with special reference to risk factors for lymph node metastasis.

A clinicopathological analysis of the risk factors for lymph node metastasis was performed in 177 patients with submucosal invasive colorectal carcinoma (CRC). The submucosal deepest invasive portion was histologically subclassified as well (W), moderately (M), or poorly (Por) differentiated. M type was further subdivided into moderately-well (Mw) and moderately-poorly (Mp) differentiated. The pattern of tumor growth was classified as polypoid growth (PG) and non-polypoid growth (NPG). Lymph node metastasis was detected in 21 (12%) of the 177 patients. Macroscopically, type IIc and IIa + IIc lesions showed a significantly higher incidence of lymph node metastasis (44% and 30%) than type IIa and I (4% and 8%). Regarding the histologic subclassification, Por and Mp lesions showed a significantly higher incidence of lymph node metastasis (67% and 37%) than W and Mw lesions (4% and 14%). NPG tumors showed a significantly higher incidence of lymph node metastasis (29%) than PG tumors (7%). The depth of submucosal invasion and lymphatic invasion (ly) were also significantly correlated with the incidence of lymph node metastasis (submucosal scanty (sm-s) invasion 4%, massive invasion 20%; ly(+) 23%, ly(-) 5%). None of the lesions with both sm-s invasion and of W or Mw type showed lymph node metastasis. These results indicate that submucosal invasive CRC with both sm-s invasion and of W or Mw type, which shows no ly, is the appropriate indication for endoscopic curative treatment.

[The risk factors of lymph node metastasis in submucosal invasive gastric carcinoma--assessment of the indication for endoscopic treatment].

Recent advances in endoscopic diagnosis and treatments have increased the number of early gastric carcinomas being treated by endoscopic resection. However, the appropriate criteria for endoscopic resection of gastric carcinomas with submucosal invasion are not completely established. During the past 12 years from 1980 to 1992, 116 lesions in 116 patients were treated by surgical operation for differentiated type submucosal invasive gastric carcinoma. In this study, the risk factors of lymph node metastasis were investigated clinicopathologically. As the result, 1) Heterogeneity of submucosal invasive tumor margin was demonstrated in 19 (16%) of the 116 lesions of which predominant histology was differentiated adenocarcinoma. 2) Lymph node metastasis was demonstrated in 16 (16%) of the 97 lesions of which histology was differentiated type. 3) Significant risk factors of lymph node metastasis was demonstrated in submucosal massive invasion (sm3), papillary adenocarcinoma, INF gamma, lymph vessel involvement (ly(+)), and existence of ulcer (ul(+)). 4) Sm3 and papillary adenocarcinoma (pap) had a higher malignant potential than ly(+), INF gamma, and ul(+) by multivariate analysis using the logistic regression. 5) All lesions with both well differentiated adenocarcinoma (tub1) and sm minimal invasion (sm1) had no lymph node metastasis. These results suggested that the lesions with both well differentiated adenocarcinoma tub1 and sm1, which have no other risk factors such as ly(+), INF gamma, and ul(+), may be considered as the appropriate indication for endoscopic treatment of gastric submucosal carcinoma.

[Assessment for development of superficial colorectal neoplasm--endoscopic and clinicopathologic analysis of 149 submucosal invasive carcinomas].

We performed the endoscopic and clinicopathologic analysis for the development of superficial colorectal carcinoma, using 149 submucosal (sm) invasive colorectal carcinomas. It was observed that superficial colorectal carcinomas had a tendency to rise by their sm massive invasion. In this study, we judged that the sm colorectal carcinomas originated from superficial colorectal carcinoma were 37 (25%) of 149 lesions, and their distribution in the colon and rectum was similar to that of advanced colorectal carcinomas, although the lesions originated from non-superficial (polypoid) colorectal carcinoma did not show so tendency. On the other hand, sm colorectal carcinomas originated from superficial colorectal carcinoma contained the evident adenomatous components in 7 (19%) of 37 lesions and had significantly higher incidence of lymph node metastasis than those originated from non-superficial (polypoid) carcinoma. These results suspected the facts as follows; 1) Superficial early colorectal carcinoma may be compatible as the origin to advanced colorectal carcinoma and has higher malignant potential than non-superficial early carcinoma. 2) Superficial colorectal carcinoma might also have the route of the development of "adenoma-carcinoma sequence", as well as "de novo" histogenesis.

The effect of dexamethasone on chronic pulmonary oxygen toxicity in infant mice.

The effect of dexamethasone (0.1, 1, and 5 mg/kg/d given subcutaneously from d 14-18) was tested in infant mice continuously exposed from birth to either humidified air or 80% oxygen. Dexamethasone significantly decreased lung wet wt (p less than 0.01), lung water (p less than 0.021), lung dry wt, protein, and DNA (p less than 0.001) in both air- and oxygen-exposed animals. Dexamethasone, however, had no effect on lung compliance measured after animals were killed on d 18. It also had no effect on the increase in the blood-air barrier thickness or decrease in the blood-air exchange surface area seen in the 80% oxygen-exposed mice. Dexamethasone decreased thymus gland wt (p less than 0.001), body wt gain (p less than 0.001), brain wt (p less than 0.001), and lung lymphocytes (p less than 0.05) in both air- and oxygen-exposed animals. The effect of 1 mg/kg and 5 mg/kg of the drug could not be differentiated. During the 4 d of drug administration, one air- and one oxygen-exposed animal died; both received 5 mg/kg/d of dexamethasone; microscopic and culture evidence of infection was not found. If dexamethasone causes similar effects in human infants with bronchopulmonary dysplasia, it should be used with great caution even for short-term clinical management.

Antiproliferative and DNA-scission activities of L-ascorbic acid in the presence of copper chelates.

L-Ascorbic acid inhibits the growth of mouse neuroblastoma and human endometrial carcinoma cells at concentrations greater than 100 microM. Under the same concentrations used in cell culture study, normal human lung fibroblasts show less sensitivity to the antiproliferative effect of ascorbate than tumor cell lines. The antitumor activity of ascorbate can be greatly potentiated by the combination with copper ions or copper chelates. The exposure of normal and tumor cells to the mixtures of ascorbate and copper chelates, especially Cu2+-o-phenanthroline and Cu2+-2,9-dimethyl-o-phenanthroline complexes, resulted in the killing of a large proportion of cell populations whereas the organic ligand portion of metal complexes was much less toxic. These copper chelates in combination with ascorbate showed different degrees of DNA-scission activities which could not be correlated with their cytotoxicities in the cell culture study. It is suggested that the primary targets of these antiproliferative agents may be on the biological sites such as cell membrane other than DNA in the nucleus which has been commonly assumed as the critical target for most free radical-generating antitumor drugs.

Atypical malignant histiocytosis. Its appearance as a single meningeal tumor or as multiple skin tumors.

We studied two unusual cases of malignant histiocytosis (MH). In one case, a solitary intracranial tumor developed in a 20-year-old man eight months before the characteristic symptoms of MH appeared. In the other, a 73-year-old man had multiple nodular skin lesions four months before malignant histiocytes appeared in his blood. In both, the tumor cells were identified as malignant histiocytes by light and electron microscopic, cytochemical, and cytoimmunological criteria.