The expression of stat91, ras-independent signal transducer and activator, in human gastric carcinomas

Upon binding of interferon (IFN) and epidermal growth factor (EGF) to their cell surface receptors, tyrosine phosphorylation of latent cytoplasmic Stat91 (Ras-independent signal transducer and activator of transcription, Stat1 alpha) protein is promptly induced and translocate from the cytoplasm to the nucleus to transduce the signal. The expression of mRNA for Stat91 was examined in 8 gastric carcinoma cell lines and 21 gastric carcinoma tissues as well as corresponding normal mucosa. Of the 8 gastric carcinoma cell lines, all expressed a 4.7 kb Stat91 mRNA and a 91 kD protein at various levels. In gastric carcinoma cell lines, the levels of Stat91 mRNA expression were compatible with those of Stat91 protein expression. In surgical cases, all the gastric carcinoma tissues and their adjacent non-neoplastic mucosa expressed Stat91 mRNA and protein. Interestingly, 14 (66%) out of 21 tumors expressed Stat91 mRNA at higher levels than their corresponding normal mucosas. Moreover, 6 (75%) of 8 tumor tissues expressed higher levels of Stat91 protein as compared with those of the corresponding normal gastric mucosa. No significant correlation was detected between the expression of Stat91 and clinicopathological feature of gastric carcinoma. These results suggest that the majority of gastric cancer in vivo harbour overexpression of Stat91 as a signal transducer in response to various cytokines or growth factors which may be implicated in the growth of gastric cancer.

Cholesterol granuloma in the middle cranial fossa: report of two cases

We report two cases of cholesterol granuloma in the middle cranial fossa. On CT the lesions appeared as a nonspecific, nonenhancing soft-tissue mass with bone erosion. On MRI they were seen as areas of high signal intensity surrounded by a low-intensity peripheral zone on both T1- and T2-weighted images. Cholesterol granuloma is thought to occur when pneumatised cells in the temporal bone become obstructed. Although this lesion usually occurs in the petrous bone, it can extend to the middle cranial fossa. The diagnosis and surgical management are discussed.

MR evaluation of tuberous sclerosis: increased sensitivity with fluid-attenuated inversion recovery and relation to severity of seizures and mental retardation

PURPOSE

To evaluate the utility and possible increased sensitivity of fluid-attenuated inversion recovery (FLAIR) images for the detection of tubers in patients with tuberous sclerosis, compared with standard T2-weighted images, and to evaluate whether the tubers are correlated with neurologic symptoms.

METHOD

We examined the number, size, and location of tubers in five tuberous sclerosis patients using T2-weighted and FLAIR images. Their intelligence quotients, ages at the onset of the first seizure, seizure types, and epileptic severity also were studied retrospectively.

RESULTS

The number of tubers observed ranged from 4 to 17 on T2-weighted images, and from 10 to 33 on FLAIR images. All the tubers, other than the myelination line on T2-weighted images, were remarkably demonstrated as high-intensity lesions on FLAIR images. No correlation was found between the neurologic outcome and the number, size, or location of tubers on FLAIR images.

CONCLUSION

FLAIR images were very sensitive for the detection of tubers, especially small subcortical ones, the number, size, and location of which are not related to the neurologic symptoms.

Functional mapping of the sensorimotor cortex: combined use of magnetoencephalography, functional MRI, and motor evoked potentials

Combined use of magnetoencephalography (MEG), functional magnetic resonance imaging (f-MRI), and motor evoked potentials (MEPs) was carried out on one patient in an attempt to localise precisely a structural lesion to the central sulcus. A small cyst in the right frontoparietal region was thought to be the cause of generalised seizures in an otherwise asymptomatic woman. First the primary sensory cortex was identified with magnetic source imaging (MSI) of somatosensory evoked magnetic fields using MEG and MRI. Second, the motor area of the hand was identified using f-MRI during hand-squeezing. Then transcranial magnetic stimulation localised the hand motor area on the scalp, which was mapped onto the MRI. There was a good agreement between MSI, f-MRI and MEP as to the location of the sensorimotor cortex and its relationship to the lesion. Multimodality mapping techniques may thus prove useful in the precise localisation of cortical lesions, and in the preoperative determination of the best treatment for peri-rolandic lesions.

A case of autoimmune bullous dermatosis with features of pemphigus vulgaris and bullous pemphigoid

Pleomorphic blisters, including tense bullae and annularly arranged vesicles around the erythema as well as erosive eruptions in the oral cavity, appeared on a 61-year-old woman 5 years after surgery for cholangiocellular carcinoma. A biopsy specimen from the oral cavity showed intraepidermal blisters, and those from skin lesions showed subepidermal blisters with infiltrates of eosinophils and neutrophils. The early-stage vesicles showed infiltrates along the epidermal-dermal junction, where electron microscopy disclosed disruption of the lamina densa, basal cells remaining on the dermis, and acantholytic keratinocytes among the infiltrates, but there was no cleavage of the epidermal-dermal junction at the lamina lucida. Direct immunofluorescence studies showed immune deposition at the intercellular space (ICS) and along the basement membrane zone (BMZ). Indirect immunofluorescence studies confirmed coexistence of IgG class anti-ICS and anti-BMZ antibodies. Although this case showed immunohistochemical features of bullous pemphigoid, the presence of suprabasal cleavage in the oral mucosa, acantholytic cells in the blister cavity, the deposition of IgG at the ICS of the perilesional epidermis, and circulating anti-ICS antibodies strongly suggested that this case was primarily pemphigus. The strong inflammation along the epidermal-dermal junction due to unknown factors may have modified the clinical appearance and the histopathology.

[Transient achromatopsia caused by cardioembolic brain ischemia]

A 51-year-old right-handed man with dilated cardiomyopathy, sleep apnea and atrial fibrillation suddenly suffered from transient color imperception, which completely recovered next morning. During the attack, both color naming and color pointing were severely disturbed, while he could correctly state the colors of named objects. There were no additional neuropsychological disturbances such as aphasia, alexia and prosopagnosia. Brain MRI revealed a new ischemic change, i.e. laminar cortical necrosis, in the right fusiform gyrus as a causative lesion as well as old asymptomatic infarcts in the left middle cerebral arterial territory. Cardioembolism was considered to be responsible for the development of brain ischemia. The transient achromatopsia is a rarely reported disease and this case appears to support 'ischemia' as its etiology.

Comparison of magnetoencephalography, functional MRI, and motor evoked potentials in the localization of the sensory-motor cortex

To clarify the topographical relationship between peri-Rolandic lesions and the central sulcus, we carried out presurgical functional mapping by using magnetoencephalography (MEG), functional magnetic resonance imaging (f-MRI), and motor evoked potentials (MEPs) on 5 patients. The sensory cortex was identified by somatosensory evoked magnetic fields using MEG (magnetic source imaging (MSI)). The motor area of the hand region was identified using f-MRI, during a hand squeezing task. In addition, transcranial magnetic stimulation localized the hand motor area on the scalp, which was mapped onto the MRI. In all cases, the sensory cortex was easily identified by MSI and the results of MSI correlated well with the findings obtained by the intraoperative recording of somatosensory evoked potentials. In contrast, the motor cortex could not be localized by f-MRI due to either the activated signal of the large cortical vein or the lack of any functional activation in the area of peri-lesional edema. MEPs were also unable to localize the entire motor strip. Therefore, at present, MSI is considered to be the most reliable method to localize peri-Rolandic lesions [corrected].

Orally active and long-term acting insulin-mimetic vanadyl complex:bis(picolinato)oxovanadium (IV)

The blood glucose level of rats with streptozotocin (STZ)-induced diabetes has been found to be normalized by administration of vanadyl or vanadate complexes. During our investigations on the development of anti-diabetic vanadyl complexes with various types of coordination mode such as V-O, V-N and V-S, we found that a new bis(picolinato)oxovanadium (IV) complex (VPA) has a strong insulin-mimetic effects as evaluated by an in vitro experiments, in which the inhibition of free fatty acid release in isolated rat adipocytes treated with epinephrine was observed to be similar to that of insulin. VPA was also effective for normalizing the blood glucose level of STZ-induced diabetic rats when given intraperitoneally or orally. The serum glucose level was maintained in the normal range for about 30 days with body weight gain after the end of oral administration of VPA for 14 days. VPA was confirmed to be an orally active and long-term acting insulin-mimetic vanadyl complex to treat insulin-dependent diabetes mellitus (IDDM) in rats.

Intradural spinal meningioma in a 5-year-old female

The case of a 5-year-old female with an intradural spinal meningioma is presented. She showed slowly progressive muscle weakness of the lower extremities commencing at 3 years. Spinal magnetic resonance imaging (MRI) demonstrated an intradural mass extending from the eleventh thoracic vertebra to the fifth lumbar vertebra, which was excised totally by means of laminoplasty. The surgical procedure brought a gradual improvement in her gait. This case is unusual because of the tumor's location (lumbar) and origin (cauda equina), and because of the onset at a relatively young age.

Inhibition of acetylcholinesterase modulates the autoregulation of cerebral blood flow and attenuates ischemic brain metabolism in hypertensive rats

We designed the present study to examine whether or not the inhibition of acetylcholinesterase modulates cerebral microcirculation in hypotension and improves brain metabolism in ischemia induced by bilateral carotid artery occlusion in hypertensive rats. Blood flow to the parietal cortex was determined by the H2 clearance method. Lactate, pyruvate, and ATP were estimated by enzymatic methods. Acetylcholinesterase inhibitor (AChEI, ENA-713), at 0.05, 0.1, or 0.5 mg/kg, was intravenously injected 10 min before either hemorrhagic hypotension or cerebral ischemia. The levels of acetylcholine in the control were 29.3 +/- 8.1 (mean +/- SD) and 39.5 +/- 8.1 pmol/mg in the cortex and hippocampus, respectively, and they were significantly decreased by 15-19% after 60 min of ischemia in the vehicle-treated rats. AChEI preserved the levels to 93-98% of the control (p < 0.05 versus vehicle). The lower limit of autoregulation was 74 +/- 9% of the resting values. The administration of AChEI helped preserve blood flow and lowered the limit to 64 +/- 6% (p < 0.05 versus control). After 60 min of ischemia, lactate increased 6.5-fold and ATP decreased to 64% of the control value. The administration of AChEI dose-dependently reduced the lactate level 1.9- to 3.9-fold and well preserved the ATP level to 94-97% of the control. The inhibition of acetylcholinesterase activity may preserve cerebral autoregulation during hypotension and protect cerebral metabolism against ischemic insult.

Cerebral blood flow and metabolism in hypertensive patients with cerebral infarction

The authors investigated, by positron emission tomography, the effect of long-standing hypertension on cerebral blood flow (CBF) and oxygen metabolism in patients with chronic atherothrombotic brain infarction. In the nonbrain infarct (non-BI) group (n = 13, mean age: sixty-two years), the regional CBF (rCBF) was decreased significantly with a rise in the mean arterial blood pressure (MABP) in the cerebral cortexes (r = -0.575) and the deep gray matter (r = -0.451), whereas the regional cerebral metabolic rate for oxygen (rCMRO2) remained unchanged. In the brain infarct (BI) group (n = 22, mean age: fifty-eight years), however, the rCBF as well as the rCMRO2 were reduced even in the normotensive patients and thus did not correlate with the MABP. These results suggest that long-standing hypertension per se causes a reduction in the rCBF but not in the oxygen metabolism with a compensatory increase in the oxygen extraction fraction. On the other hand, patients with brain infarction, even normotensives, show a diffuse decrease in cerebral circulation and metabolism, which is probably due to the more severe sclerotic changes that take place in the cerebral vessels.

Cell surface proteolysis by serine proteinases enhances RGD-sensitive melanoma cell adhesion on fibrinogen and vitronectin

Tumor cells avidly secrete various proteinases, and cascades of proteolytic activation occur around the cells. Therefore, cell surface receptors of tumor cells are under the constant influence of proteinases. In this study, the effects of serine proteinases on integrin-medicated cell-matrix interactions were studied in C32TG and Mewo human melanoma cells. These melanoma cells were pretreated with proteinases and their adhesive properties on various substrata were evaluated by cell adhesion assays. Paradoxically, appropriate cell surface proteolysis enhanced the RGD-sensitive cell adhesion on fibrinogen and vitronectin, but not the RGD-insensitive adhesion on type I collagen or laminin. Pretreatment of these cells with 0.1 to 1 microM of trypsin, chymotrypsin, or plasmin for 30 min at 37 degrees C increased the number of spread cells on fibrinogen and vitronectin by 200-300%. The enhancement of cell spreading was not accompanied by up-regulation of the relevant RGD-sensitive integrin expression. Analysis of the cell surface receptor by GRGDSPK-Sepharose affinity chromatography showed that trypsin treatment did not up-regulate alpha v beta 3 integrin, an RGD-sensitive receptor for fibrinogen and vitronectin in the melanoma cells, nor the induced appearance of novel receptors. Treatment of cells with 100 nM proteinases increased cell binding of both monoclonal and polyclonal antibodies against alpha v beta 3 integrin subunits by 70%, but not that of monoclonal antibody against alpha 2, alpha 3, or alpha 6 subunit, indicating that cell surface proteolysis exposed more alpha v beta 3 integrin on the cell surface. These results suggest that exposure of alpha v beta 3 integrin is a part of the mechanisms underlying the serine proteinase-induced enhancement of melanoma cell adhesion on fibrinogen and vitronectin.

Expression of the proliferative cell nuclear antigen (PCNA) in adenocarcinoma of the gallbladder, and its relationship to prognosis

Proliferative cell nuclear antigen (PCNA) has been correlated with degree of differentiation in some tumours, but information on PCNA expression in adenocarcinoma of the gallbladder is currently limited. Therefore, we examined PCNA expression in adenocarcinoma of the gallbladder, and its relationship to prognosis. The expression of PCNA was studied by immunohistochemistry in 70 formalin-fixed, paraffin-embedded specimens of surgically removed adenocarcinomas of the gallbladder. The percentage of stained nuclei was recorded, and the PCNA-labelling index (LI) was expressed as the ratio of labelled nuclei to the total number of nuclei counted. In all histological types, the PCNA-LI in the invasive zone of the tumour was higher than that in the luminal zone of the tumour (p < 0.05). The PCNA-LI showed a stepwise increase with decreasing degrees of differentiation in both the invasive and the luminal zone of the tumour (p < 0.01). In advanced adenocarcinomas, patients whose tumours had a PCNA-LI of less than 35 in the invasive zone had significantly longer survival rates than those with PCNA-LI equal to or greater than 35 (p < 0.01). Multivariate analysis, using the Cox proportional hazards model, indicated that a PCNA-LI > or = 35 in the invasive zone of the tumour was a significantly unfavourable prognostic factor (p = 0.002). The PCNA-LI of routinely processed specimens of adenocarcinoma of the gallbladder may be helpful for the evaluation of cell proliferation and prognosis.

Venous tumor thrombosis and cavernous transformation of the portal vein in a patient with gastric carcinoma

A case of extensive extra- and intrahepatic portal tumor thrombosis, with no metastatic foci in liver parenchyma, secondary to advanced gastric carcinoma in a 69-year-old man is reported. The portal tumor thrombosis was characterized by enlargement of the thrombosed segment of the vein, decreased density mass without intraluminal enhancement of the involved vein, nonvisualization of the portal venous branch in the involved lobe, and the so-called cavernous transformation of the portal vein. The surgically resected gastric specimen showed Borrmann type 3 advanced papillary adenocarcinoma. The portal tumor thrombus is presumed to have arisen from vascular invasion in the primary foci of gastric carcinoma, and then to have permeated the portal vein without invasion of liver parenchyma.

Mechanism of action of antimycobacterial activity of the new benzoxazinorifamycin KRM-1648

The mechanism of antimicrobial activity of KRM-1648 (KRM), a new rifamycin derivative with potent antimycobacterial activity, was studied. Both KRM and rifampin (RMP) inhibited RNA polymerases from Escherichia coli and Mycobacterium avium at low concentrations: the 50% inhibitory concentrations (IC50s) of KRM and RMP for E. coli RNA polymerase were 0.13 and 0.10 micrograms/ml, respectively, while the IC50s for M. avium RNA polymerase were 0.20 and 0.07 microgram/ml. Both KRM and RMP exerted weak inhibitory activity against Mycobacterium fortuitum RNA polymerase, rabbit thymus RNA polymerases, E. coli DNA polymerase I, and two types of reverse transcriptases. Uptake of 14C-KRM by M. avium reached 18,000 dpm/mg (dry weight) 1.5 h after incubation, while uptake by E. coli cells was slight. KRM was much more effective in inhibiting uptake of 14C-uracil than was RMP (IC50 of KRM, 0.04 microgram/ml; IC50 of RMP, 0.12 microgram/ml). These findings suggest, first, that the potent antimycobacterial activity of KRM is due to inhibition of bacterial RNA polymerase and, second, that the activity of KRM against target organisms depends on target cell wall permeability.

Isolation and characterization of a cDNA that encodes maize glutamate dehydrogenase

A full-length cDNA clone, pMGDH1, encoding maize NADH-glutamate dehydrogenase (NADH-GDH) was isolated from a maize root cDNA library. The identity of the cDNA was established by the coincidence of the structure of the purified protein with that inferred from the nucleotide sequence of the cDNA. pMGDH1 had a cDNA insert of 1,638 bp and the open reading frame encoded 411 amino acid residues. The deduced amino acid sequence was similar to putative partial sequences of GDHs from higher plants and to the sequences of GDHs from organisms as diverse as mammals and bacteria. The NH2-terminal sequence deduced from the open reading frame had a typical structure that is associated with the import of proteins into the mitochondrial matrix. The cDNA hybridized to an RNA of about 1.6 kb. This transcript was more abundant in roots than in leaves and was localized in the bundle sheath cells in leaf tissues. Analysis of genomic DNA by Southern hybridization suggested the existence of gene(s) for another NADH-GDH subunit(s).

Inhibitory effect of cold stress on lung tumours induced by 7,12-dimethylbenz[a]anthracene in mice

The effect of cold stress on lung tumours induced by 7,12-dimethylbenz[a]anthracene (DMBA) was investigated in ICR male and female mice. When mice were exposed to cold stress at 0 +/- 1 degree C for 2 h, three times per week (every other day) for 3 months, the rectal temperatures and hepatic glutathione levels were significantly decreased. On the other hand, when DMBA (10 mg/kg) was subcutaneously injected into neonatal mice, lung tumours were observed in 81.8% of non-stressed mice of both sexes 4 months after injection. However, when mice treated with the same dose of DMBA were exposed to cold stress under the same conditions, lung tumours were observed in 53.3% and 30.3% of the male and female mice 4 months after DMBA injection. In addition, although DMBA (1 mg/kg) caused lung tumours in 20% or 40% of the treated male or female mice 4 months after injection, it did not cause lung tumours in all of the male and female mice exposed to cold stress. These results suggest that cold stress may inhibit lung tumours induced by chemicals.

Brain infarction developed in hypertensive and normotensive patients during hospitalization--hemodynamic factors

To determine the effects of changes in blood pressure (BP) on the development of ischemic stroke, 17 patients who developed acute brain infarction during hospitalization were analyzed in relation to the vascular risk factors such as hypertension, previous stroke, diabetes mellitus, and hyperlipidemia. Their BPs were retrospectively referred to the onset of stroke. The average values of mean arterial blood pressure (MABP) on admission were 137 mmHg in hypertensive patients (HT; n = 9) and 101 mmHg in normotensives (NT; n = 8). HT patients received antihypertensive treatment after admission and MABP decreased by 22 mmHg (14%) prior to the ictus (three to sixty-five days after admission). MABP in NT patients remained constant before the attack (-1.4 mmHg, four to one hundred ten days after admission). Similarly, MABP decreased by 17 mmHg (four to ninety-three days) before the ictus in patients with previous stroke (n = 9), whereas it changed only a little in patients without history of stroke (n = 8). BP in each group elevated immediately after the stroke and gradually decreased to 90% of the resting level after two weeks. An excessive reduction of BP may induce brain infarction in HT or chronic stroke patients or cause it to recur.

Cerebral blood flow and brain function in hypertension

In mild hypertensive patients, regional cerebral blood flow, measured by positron emission tomography, was reduced in the frontal cortex and basal ganglia compared with normotensive patients. In moderate to severe hypertensive patients, cerebral oxygen metabolism was diminished, although the patients were neurologically intact. In elderly hypertensives, white matter vascular lesions on brain imaging were more frequent and cognitive function was impaired, compared with age-matched normotensives. In nontreated spontaneously hypertensive rats (SHR), local cerebral blood flow was decreased in the cortex and thalamus, compared with normotensive rats (NTR). Spatial memory and learning in maze tests were more impaired in aged SHR than in old NTR or young SHR. This impairment was related to decreased cerebral glucose utilization in the medial septal nucleus, hippocampus, and other regions of the brain. Reduced cerebral blood flow, increased media thickness of the cerebral arteries and impaired cognitive function in SHR were improved by long-term antihypertensive treatment. In humans as well as animals, long-standing hypertension per se leads to reductions in cerebral blood flow, metabolism, and cognitive function, each of which possibly may be improved by controlling hypertension with long-term antihypertensive treatment.

"Rebound" phenomenon of hepatitis C viremia after interferon therapy in "relapsed" patients with chronic hepatitis C

The correlation between serum hepatitis C virus (HCV)-RNA and aminotransferase levels following completion of interferon therapy was evaluated in eight relapsed patients with chronic hepatitis C. Both HCV-RNA and aminotransferase levels were significantly increased in the relapsed patients 1 month after completion of therapy, compared to pretreatment values, despite aminotransferase levels being normal and HCV-RNA being undetectable by reverse transcription polymerase chain reaction assay at the end of therapy. The serum levels of HCV-RNA and aminotransferase were significantly elevated 1 and 2 months post-treatment. They then decreased to pretreatment values 3-5 months after the completion of therapy. Thus, in relapsed patients after the completion of therapy, the changes in HCV-RNA levels preceded the elevation in aminotransferase levels. These findings suggest a correlation between serum HCV-RNA levels and aminotransferase levels in relapsed patients with chronic hepatitis C after the completion of interferon therapy.

Deterioration of mechanical properties of composite resins

The deterioration of the mechanical properties of composite resins was examined. The bending strength and the stress relaxation rate for sixteen experimental composite resins with different filler shapes, particle sizes and filler contents immersed in distilled water for 0-60 days were measured. The bending strength of all of the composites decreased with the increase of the immersion time in water. The composites with a high filler content (65 vol%) showed a greater decreasing ratio of bending strength than those with low filler content (40 vol%). The stress relaxation rate also increased with and increase of immersion time. The phenomena may be caused by the hydrolytic degradation of the silane coupling agent (gamma-MPTMS).

Autopsy findings of Addison's disease caused by systemic cytomegalovirus infection in a patient with acquired immunodeficiency syndrome

We previously reported a case of Addison's disease associated with acquired immunodeficiency syndrome (AIDS) (Endocr J, 41:13, 1994). A 46-year-old man with hemophilia B and AIDS was diagnosed as Addison's disease. The positive cytomegalovirus (CMV) antigen in urine suggested that CMV adrenalitis may have caused the adrenal insufficiency. Despite treatment with ganciclovir, the patient died one year later. Autopsy findings revealed that the typical inclusions of CMV were seen in the lung, adrenal glands (both cortex and medulla) and small intestine. Here, we describe the subsequent clinical course and postmortem findings of this case.

Immunohistochemical analysis of nm23 gene product in human gallbladder carcinomas

The expression of nm23, the product of a candidate suppressor gene for tumour metastasis, was examined immunohistochemically in human gallbladder carcinomas and compared with clinicopathological features. Seventy-eight (72%) of 107 carcinomas expressed nm23 protein regardless of histological type, while non-neoplastic mucosa occasionally showed very weak immunoreactivity to nm23. No obvious correlation was observed between nm23 protein expression and depth of tumour invasion or tumour stage. The expression of nm23 protein was detected in 60% and 74% of the cases with and without lymph node metastasis, respectively, indicating no relationship to metastatic ability. Fifty-eight percent of the cases showed reduction of nm23 immunoreactivity in tumour cells invading the stroma at the border of tumour cell nests compared with cells at the centre of the tumour. Only 7% of the cases showed increased nm23 expression in tumour cells at the border. These results suggest that in gallbladder carcinoma decreased expression of nm23 may not have implications for metastasis but may play a part in local invasion.