Barrel rotation evoked by intracerebroventricular injection of somatostatin and arginine-vasopressin is accompanied by the induction of c-fos gene expression in the granular cells of rat cerebellum

Intracerebroventricular (i.c.v.) injection of somatostatin (SS) or arginine-vasopressin (AVP) elicits barrel rotation (BR) in rats. To identify the potential neuron structures involved in this characteristic behavior, the regional expression of the c-fos gene in rat brain after i.c.v. injection of SS (10 micrograms) or AVP (1 micrograms) was examined by hybridization histochemistry. The c-fos expression could serve as a marker of neuronal activity and/or neural transmission. Following SS-induced BR, c-fos gene expression was observed in the lingula, uvula, nodulus, simplex, centralis, and culmen of the cerebellum, while following AVP-induced BR, c-fos gene expression was observed in the first four of the above-mentioned regions of the cerebellum, but not in the centralis or culmen. In these regions, the c-fos mRNA signals were observed on the granular layer. Expression of the c-fos gene was immediately and transiently induced and was not observed in rats in which BR was not evoked after SS or AVP injection. In both control rats and SS- or AVP-injected rats, the c-fos gene expression was induced in the piriform cortex and the flocculus of the cerebellum. The findings suggest that BR is a manifestation of behavior induced by massive transsynaptic activation of the granular cells in the cerebellum.

Effect of parenteral administration of selected nutrients and central injection of gamma-globulin from antiserum to neuropeptide Y on growth hormone secretory pattern in food-deprived rats

Serial changes in growth hormone (GH) secretory pattern during 72 h food deprivation and in response to refeeding after 72 h food deprivation were observed in adult male Wistar rats. In addition, the effects of intravenous administration of glucose, fatty acids or amino acids and central injection of gamma-globulin from antiserum to human neuropeptide Y (NPY) on the GH secretory pattern were examined in 72 h food-deprived rats. Rats were provided with chronic indwelling right atrial cannula and serial blood specimens were withdrawn via the cannula every 10 min using an automatic blood-sampling device. The GH secretory pattern was analyzed using a Pulsar computer program. In fed rats, episodic GH secretion with an amplitude exceeding 350 ng/ml occurred at 170-min intervals and intervening trough GH levels were less than 10 ng/ml. During the 72 h food deprivation, the amplitude of pulsatile GH secretion decreased progressively without altering the pulse frequency. When 72 h food-deprived rats were refed lab chow, the pulse frequency and the pulse amplitude increased rapidly and lasted for 6-8 h. Normal pulsatile GH secretion resumed by 10-12 h after refeeding following the 72 h food deprivation. To identify the specific nutrient (i.e. glucose, fatty acids or amino acids) serving as the signal causing restoration of the central drive to GH secretion, glucose solution (2 or 6 kcal), lipid emulsion (2 or 6 kcal) or amino acid solution (2 kcal) was administered intravenously to the 72 h food-deprived rats.(ABSTRACT TRUNCATED AT 250 WORDS)

[Quantitative analysis of right ventricular overloading by 201Tl myocardial SPECT]

Clinical usefulness of quantitative analysis of right ventricular overloading was evaluated by 201Tl myocardial SPECT in comparison with cardiac catheterization and MRI. Seventy-four MBq of 201TlCl was intravenous injected and 201Tl myocardial SPECT was performed on 40 patients (mean age: 61.0 +/- 11.8) with right ventricular overloading. Regions of interest (ROI) were selected on right and left ventricular walls in a midventricular short axis image of SPECT and uptake of each ROI were counted. The right ventricle (RV)/left ventricle (LV) 201Tl uptake ratio (R/L-Tl) was calculated. Wall thickness of RV and LV were measured on MRI and the RV/LV wall thickness ratio (R/L-WT) was calculated. RV and LV pressure were recorded in cardiac catheterization, and the RV/LV systolic pressure ratio (R/L-P) was calculated. There was significant positive correlation (Y = 0.73X + 0.19, r = 0.71, p < 0.001) between R/L-Tl and R/L-WT. R/L-Tl was positively correlated with R/L-P in patients with pressure overload (Y = 1.14X - 0.049, r = 0.85, p < 0.001) and in patients with volume overload (Y = 0.51X + 0.023, r = 0.88, p < 0.001) and the slope of the regression line in patients with pressure overload was significantly steeper than that in patients with volume overload (p < 0.001). In conclusion, quantitative analysis of right ventricular overload by 201Tl myocardial SPECT is useful to estimate RV/LV wall thickness ratio and pressure ratio.

Progression of signet ring cell carcinomas in the human stomach

BACKGROUND

Stomach cancers show various growth patterns. It remains to be clarified how this variability is related to the genetic changes that occur during tumor progression.

METHODS

To estimate the genetic changes from tumor ploidy, maps were made (using DNA cytofluorometry of metaphase cells in histologic sections) of 39 advanced signet ring cell carcinomas of the human stomach and correlated with tumor stage and the size of the primary mucosal lesion.

RESULTS

Aneuploid area and multipattern aneuploidy were particularly common in advanced cancers with primary mucosal lesions smaller than 2 cm in diameter, of which a large portion were predominantly aneuploid and already diffusely infiltrating. As the tumor stage advanced, the incidence of aneuploidy in the mucosal lesion increased, whereas predominantly aneuploid tumors were less common as primary mucosal lesions became larger. Purely diploid areas with an incidence of polyploidy as low as in early cancers were common in advanced cancers. In addition, there were diploid-appearing cancer cells that infiltrated diffusely and were accompanied by polyploid as often as aneuploid cells. Some of these were aneuploid at the chromosomal level.

CONCLUSIONS

In signet ring cell carcinoma, aneuploid cells show higher invasive activity toward the extramucosal part and may occur incidentally in originally diploid tumors, depending on the degree of genetic instability. An analysis of polyploidy is useful for differentiating cytometrically diploid (but actually, aneuploid) cells from diploid cells with minor genetic abnormalities.

Reconstruction of alveolus-like structure from alveolar type II epithelial cells in three-dimensional collagen gel matrix culture

The purpose of this study is to reconstruct an alveolus-like structure from alveolar type II epithelial cells in a culture condition. Isolated alveolar type II epithelial cells of the rat were cultured in a three-dimensional collagen gel matrix. Single type II cells formed cellular aggregates that had a lumen after cell division in this culture condition. Through proliferation of the component cells, these aggregates grew to assume a globular or branching structure, part of which in turn developed into a large, cystic alveolus-like structure. This structure consisted of flattened epithelial cells intermingled with cuboidal epithelial cells. In these structures, the surfactant production was confirmed by immunohistochemistry and electron microscopy. To our knowledge, this is the first report of a reconstruction of an alveolus-like structure in a three-dimensional collagen gel matrix culture. This culture system seems to provide an appropriate physiological environment in which to study the differentiation and disorders of pulmonary alveoli.

Effect of bilineobin, a thrombin-like proteinase from the venom of common cantil (Agkistrodon bilineatus)

A thrombin-like proteinase, named bilineobin, was isolated from Agkistrodon bilineatus venom by Sephadex G-75, DEAE-Sephacel and Heparin-Sepharose CL-6B column chromatography. The purified enzyme has a mol. wt of 57,000 and catalysed the hydrolysis of arginine esters and thrombin substrates Boc-Val-Pro-Arg-MCA and Boc-Asp(OBz)-Pro-Arg-MCA. Although bilineobin converted fibrinogen into fibrin resulting in the production of fibrinopeptides, the activity was relatively low (0.65 NIH units/mg). Fibrinopeptides released upon hydrolysis by this proteinase were identified as fibrinopeptide A (FpA) and fibrinopeptide B (FpB) by measuring fast atom bombardment (FAB) mass spectra and amino acid sequence. This indicates that bilineobin hydrolyses the Arg(19)-Gly(20) bond in the A alpha chain and the Arg(21)-Gly(22) bond in the B beta chain of the bovine fibrinogen molecule. Kinetic study of FpA and FpB release reveals that bilineobin has a preference for cleaving the B beta chain. In addition, bilineobin is resistant to thrombin inhibitors such as hirudin. These suggest that the mechanism of action of bilineobin is similar but not identical to that of thrombin. It was demonstrated that the NH2-terminal region of bilineobin has significant similarities in sequence with thrombin-like proteinases from other snake venoms; however, only three residues were common with thrombin up to residue number 24.

Occurrence of paroxysmal synchronous EEG discharges in subcortical arteriosclerotic encephalopathy (Binswanger's disease)

A 72-year-old patient with von Recklinghausen's disease showed akinetic mutism within 6 months of the onset of dementia. The findings of diffuse cerebral atrophy on CT and periodic synchronous discharges (PSDs) in EEG suggested Creutzfeldt-Jakob disease. However, autopsy findings of diffuse softening of the subcortical white matter and marked arteriosclerotic changes of the subcortical arterioles with sparing of the cortex in the cerebrum confirmed a diagnosis of Binswanger's disease. Binswanger's disease should be included in the differential diagnosis of dementia showing PSDs in EEG.

Somatostatin reduces transcription of the growth hormone gene in rats

To examine whether somatostatin (SS) exerts influences on the steady state levels of GH-releasing factor (GRF), the effect of SS on GH gene transcription was examined in rats. This approach was used because it has been shown that GRF stimulates GH gene transcription independent of GH release, and SS does not inhibit basal or GRF-stimulated GH gene transcription. Therefore, it is assumed that an effect of SS on GH gene transcription would be mediated by a change in GRF levels. Adult female Sprague-Dawley rats were provided with right atrial cannulae. Studies were performed using unanesthetized rats. Pituitary GH gene transcription was measured by transcription assay. An iv administration of antiserum to rat GRF 150 min previously significantly decreased GH gene transcription compared with that in control rats given normal goat serum. A continuous infusion of SS (300 micrograms/kg.h) via the cannula for 150 min significantly decreased GH gene transcription compared with that in control rats receiving 0.9% NaCl. When GRF (3 micrograms/kg.h) was given simultaneously with SS (300 micrograms/kg.h), GH gene transcription increased significantly compared with that in rats receiving SS infusion alone. After the withdrawal of SS infusion, GH gene transcription rapidly and significantly increased. The data suggest that SS reduces the steady state levels of GRF.

Molecular characterization of the family of the N-methyl-D-aspartate receptor subunits

cDNA clones for four different N-methyl-D-aspartate (NMDA) receptor subunits (NMDAR2A-NMDAR2D) were isolated through polymerase chain reactions followed by molecular screening of a rat brain cDNA library. These subunits are only about 15% identical with the key subunit of the NMDA receptor (NMDAR1) but are highly homologous (approximately 50% homology) with one another. They also commonly possess large hydrophilic domains at both amino- and carboxyl-terminal sides of the four putative transmembrane segments. NMDAR2A and NMDAR2C expressed individually in Xenopus oocytes showed no electrophysiological response to agonists. However, these subunits in combined expression with NMDAR1 markedly potentiated the NMDAR1 activity and produced functional variability in the affinity of agonists, the effectiveness of antagonists, and the sensitivity to Mg2+ blockade. Thus, NMDAR1 is essential for the function of the NMDA receptor, and multiple NMDAR2 subunits potentiate and differentiate the function of the NMDA receptor by forming different heteromeric configurations with NMDAR1. Northern blotting and in situ hybridization analyses revealed that the expressions of individual mRNAs for the NMDAR2 subunits overlap in some brain regions but are also specialized in many other regions. This investigation demonstrates the anatomical and functional differences of the NMDAR2 subunits, which provide the molecular basis for the functional diversity of the NMDA receptor.

[Transthoracic Doppler color imaging of the blood flows in the left coronary septal branches]

This study characterized blood flow signals derived from the left coronary septal branches by transthoracic Doppler color flow imaging. In the anterior ventricular septum, the signal was detected in 7 of 13 patients with aortic stenosis, 8 of 34 with hypertrophic cardiomyopathy, and 5 of 144 patients with other diseased states. The peak diastolic flow velocity assessed by a pulsed Doppler technique ranged 21-115 cm/s (mean 57). Systolic signal was depicted in 13 of the 20 with the diastolic signal, indicating retrograde flow direction in all of them. The peak negative systolic component ranged 11-80 cm/s (mean 40). Peak diastolic flow velocity of the left anterior descending artery was higher in patients with the septal branch flow signal than in those without the signal (53 +/- 24 vs 31 +/- 11 cm/s). Patients with the signal showed larger transvalvular pressure gradient in aortic stenosis, and greater septal thickness in hypertrophic cardiomyopathy than in those without the signal. In conclusion, transthoracic visualization of the septal branch flow signal by Doppler color flow mapping is attributable to increased coronary blood flow at rest which is probably due to excessive load and/or septal hypertrophy. Augmented systolic retrograde flow may play additional role in the diastolic high velocity flow in the septal perforator.

Differentiation of brown adipose cells in three-dimensional collagen gel culture

Brown adipose cells are heat-producing cells through non-shivering thermogenesis by intramitochondrial "thermogenin". This specific protein is a marker for their cellular differentiation. It has long been known that cultured brown adipose cells in monolayer rapidly lose the thermogenin bioactivity. In this study, we cultured brown adipose cells in three-dimensional type I collagen gel matrix. Under this culture condition, they were able to survive, and differentiated morphologically and functionally for a long period of time, especially exhibited the characteristic immunohistochemical activity of thermogenin. These findings suggest that brown adipose cells differentiate in type I collagen gel. In this condition, cholera toxin or BRL 37344, one of beta 3-adrenoceptor agonists, specifically stimulated the brown adipose cells.

[A case of stunned myocardium: dual SPECT findings similar to acute myocardial infarction (AMI)]

Emergent cardiac catheterization was performed on a 70-year-old female patient who was admitted for further evaluation of acute myocardial infarction. Coronary angiography didn't reveal any significant stenotic lesion, but levogram showed extensively abnormal contractility around the center of the apex region. On the second hospital day, 99mTc-PYP/201TlCl dual SPECT gave findings similar to those found in acute myocardial infarction, but myocardium--released enzyme stayed within the normal range. Two weeks after, 201TlCl myocardial scintigraphy showed disappearance of the perfusion defect, and normal contractility was observed on the levogram of the chronic phase. Since this case was clinically denied to be myocardial infarction, it was considered a typical case of stunned myocardium which showed prolonged left ventricular abnormal contractility with transient myocardial ischemia. This is a case suggestive for estimations of myocardial reversibility in patients with myocardial perfusion and metabolic disorder in dual SPECT.

[Effect of verapamil on myocardial ischemia in patients with hypertrophic cardiomyopathy: evaluation by exercise 201Tl SPECT]

Effect of verapamil on myocardial ischemia in patients with hypertrophic cardiomyopathy (HCM) was evaluated by exercise stress myocardial 201Tl SPECT (EX-Tl). EX-Tl were performed before and after 8.8 weeks of oral verapamil (240 mg/day) in 12 patients with HCM who showed transient 201Tl perfusion defects under control conditions. 201Tl perfusion defect was visually scored and judged for 4 grades as normal (0), mild defect (1), moderate defect (2), and severe defect (3). Transient Dilation Index (TDI) was calculated as an index of subendocardial ischemia. Improvements of defect score were demonstrated in 10 patients after administration of verapamil. Two patients showed no change of defect score. Mean defect score decreased significantly from 5.50 to 3.03 (p < 0.001). Although 11 of 12 patients showed abnormal TDI under control conditions, 10 of them revealed improvements of TDI and 7 of those 10 patients disclosed normal TDI after verapamil. Mean TDI decreased from 1.263 to 1.090 significantly (p < 0.01). In conclusion, verapamil may improve myocardial ischemia in patients with HCM.

Differentiation of human thyroid follicle cells from normal subjects and Basedow's disease in three-dimensional collagen gel culture

Thyroid follicles, an essential functional unit of the thyroid, exist in the extracellular matrix of the tissue in vivo. Therefore, in any monolayer culture system, the follicles cannot be reconstructed. Our previous study adopting three-dimensional collagen gel culture showed that isolated porcine follicle cells reconstructed thyroid follicles specific for the thyroid gland in vivo. To elucidate whether this culture system is also applicable to human follicle cells, and furthermore to provide a culture system for investigations of the pathogenesis of human thyroid diseases, we tried to culture isolated human follicle cells of normal thyroid tissue and of Basedow's disease in three-dimensional collagen gel. In this culture system, they apparently reconstructed thyroid follicles. The component cells of the reconstructed follicles exhibited structural polarity specific for human thyroid follicle cells and produced thyroid hormones. In addition, the cells responded to a TSH-stimulation in terms of morphological and functional differentiation, and they presented HLA-DR antigen with an interferon-gamma-stimulation. This report is a first instance of reconstruction of human thyroid follicles and HLA-DR antigen induction in three-dimensional follicle structures in vitro. This culture system provides a more physiological environment in vitro for biological and pathogenetic investigations of human thyroid follicle cells than the monolayer culture system. Further experiments using this method will probably provide new clues to the pathogenetic mechanisms of human thyroid diseases.

Autopsy report of primary CNS B-cell lymphoma indistinguishable from multiple sclerosis: diagnosis with the immunoglobulin gene rearrangements analysis

We report a case of primary CNS B-cell lymphoma indistinguishable from multiple sclerosis (MS). MRI of the head showed the spontaneous disappearance of the white matter lesions and the progressive cerebral atrophy. The brain biopsy failed to make a diagnosis of CNS lymphoma but rather suggested MS. Although the primary CNS lymphoma was suspected at autopsy, the immunohistochemical study showed the CNS-infiltrating lymphoid cells comprising both T-cells and B-cells. Analysis of the immunoglobulin and T-cell receptor gene rearrangements first provided evidence of primary CNS B-cell lymphoma.

[Ultrasonic tissue characterization in hypertrophic cardiomyopathy: analysis of three-layered appearance of the ventricular septum by apical approach]

In normal hearts, two-dimensional echocardiography from the apical window displays the left ventricular wall as a three-layered appearance (TLA): central bright layer and bilateral sonolucent zones. The TLA is considered to reflect the normal myocardial architecture: the predominant latitudinal fiber bundles of the midwall layer, and longitudinal or oblique ones on both sides. We analysed the TLA of the ventricular septum in 20 normal subjects, 20 patients with left ventricular hypertrophy due to pressure load (LVH), and 81 patients with hypertrophic cardiomyopathy (HCM). Of the 81 HCM patients, the layering was often obscure or absent in 53 (65%), whereas LVH patients showed clear TLA as well as normal hearts. In patients with severe layering disorder (n = 30), the age at diagnosis was lower (40 +/- 15 vs 50 +/- 12, p less than 0.05), and familial occurrence (53 vs 11%, p less than 0.01) and severe functional limitation (NYHA greater than or equal to III) were more common (27 vs 4%) than in those with clear TLA (n = 28). The disturbed layering detectable by echocardiography may reflect the disorder of basic myocardial fiber architecture in the ventricular septum, and is likely to become a useful marker of the pathologic severity of the disease.

[Development and progression of undifferentiated carcinomas in the stomach]

Pathohistological studies of resected human stomachs and of experimental gastric cancers induced by ENNG have revealed that undifferentiated carcinomas arise at the neck region of glandular tubules both in the fundic and the pyloric mucosa, and tumor cells disclose the earliest invasion in the lamina propria by dripping from the glandular tubule. At earlier stages, the carcinoma cells tend to be confined to the middle level of the mucosa, and they extend to the horizontal direction of the mucosa. Most carcinomas at earlier stages comprise the diploid cell line. When tumors grow beyond a size of 2 cm in diameter in the mucosal layer, they begin to invade into the submucosal layer. As tumors grow, aneuploid and polyploid cancer cells arise in the diploid cell population. This is a kind of tumor progression. Aneuploid cancer cells disclose a more invasiveness, and they are ready to invade into the deep layer of the gastric wall. Scirrhous cancers are mostly composed of aneuploid cells, and it is suggested that small mucosal cancers which exclusively consist of aneuploid cells may become scirrhous cancers in a relatively short period.

Molecular characterization of a novel metabotropic glutamate receptor mGluR5 coupled to inositol phosphate/Ca2+ signal transduction

A cDNA clone for a new metabotropic glutamate receptor, mGluR5, was isolated through polymerase chain reaction-mediated DNA amplification by using primer sequences conserved among the metabotropic glutamate receptor (mGluR) family and by the subsequent screening of a rat brain cDNA library. The cloned receptor consists of 1171 amino acid residues and exhibits a structural architecture common to the mGluR family, possessing a large extracellular domain preceding the seven putative membrane-spanning segments. mGluR5 shows the highest sequence similarity to mGluR1 among the mGluR members and is coupled to the stimulation of phosphatidylinositol hydrolysis/Ca2+ signal transduction in Chinese hamster ovary cells transfected with the cloned cDNA. This receptor also resembles mGluR1 in its agonist selectivity and antagonist responses; the potency rank order of agonists for mGluR5 was determined to be quisqualate greater than L-glutamate greater than or equal to ibotenate greater than trans-1-aminocyclopentane-1,3-dicarboxylate. Blot and in situ hybridization analyses indicated that mGluR5 mRNA is widely distributed in neuronal cells of the central nervous system and is expressed differently from mGluR1 mRNA in many brain regions. This investigation thus demonstrates that there is an additional mGluR subtype which closely resembles mGluR1 in its signal transduction and pharmacological properties and is expressed in specialized neuronal cells in the central nervous system.

Systemic administration of recombinant human growth hormone induces expression of the c-fos gene in the hypothalamic arcuate and periventricular nuclei in hypophysectomized rats

The neuronal expression of the protooncogene c-fos could serve as a marker of neural activity. To identify the brain sites responding to GH, rat brains after systemic administration of recombinant human GH (rhGH) were processed for hybridization histochemistry for c-fos mRNA. Adult male Wistar rats were hypophysectomized 10 days before rhGH administration. After hypophysectomy, rats received sc cortisone acetate (0.5 mg/kg BW) and L-T4 (20 microgram/kg BW) daily. Four international units (1.33 mg) of rhGH were given iv through an indwelling right atrial cannula. Vehicle was administered to control animals. The rhGH treatment was accompanied by expression of the c-fos gene in the arcuate nucleus (ARC) of the hypothalamus. The accumulation of the c-fos mRNA was transient, reaching maximum values at 60 min and decreasing thereafter to reach control levels within 120 min after rhGH injection. Among control animals, c-fos gene expression was not detected in the ARC. The c-fos mRNA was also detected in the paraventricular nucleus after rhGH administration; however, it was comparable to that in control animals. When rhGH was administered twice at 40-min intervals, c-fos gene expression was induced in the periventricular nucleus (PeV) as well as the ARC 40 min after the second rhGH injection. Throughout the studies, c-fos mRNA was not detected other than in the ARC, paraventricular nucleus, and PeV in the hypothalamus. In the ARC, distribution of the cells expressing the c-fos gene appears to overlap at least in part with somatostatin (SS) mRNA-containing cells. In the PeV, it appeared to correlate generally with the distribution of SS mRNA-containing cells. The data suggest that GH feeds back on neurons of hypothalamic PeV and ARC expressing SS mRNA, and that c-fos expression is involved in the feedback mechanism.

[Repeated blackout in a patient with accelerated idioventricular rhythm]

There has been no report that Accelerated Idioventricular rhythm (AIVR) causes a syncope attack. The patient described in this report is very rare because AIVR chronic without any heart diseases has been observed for 13 years, and because it is considered that AIVR is closely associated with his repeated blackouts. A 62-year-old male was admitted to our hospital because of repeated syncopal attacks. He reported that he occasionally felt lightheaded after strenuous lifting and pushing or pulling against resistance. We found that AIVR could produce a remarkable arterial pressure drop partly because of ventricular asynergy and loss of timed atrial contribution. Furthermore, we observed syncopal attacks during Valsalva maneuver and found abnormalities of baroreceptor reflex (Lack of reflex tachycardia and weakened evershoot phenomenon). It is concluded that AIVR is not a benign arrhythmia in this patient because it has been a possible cause of syncope attack due to systemic arterial pressure drop and baroreceptor abnormalities.

Structures and properties of seven isoforms of the NMDA receptor generated by alternative splicing

We here report the existence of 6 additional isoforms of the NMDA receptor generated via alternative splicing by molecular analysis of cDNA clones isolated from a rat forebrain cDNA library. These isoforms possess the structures with an insertion at the extracellular amino-terminal region or deletions at two different extracellular carboxyl-terminal regions, or those formed by combinations of the above insertion and deletions. One of the deletions results in the generation of a new carboxyl-terminal sequence. All these isoforms possess the ability to induce electrophysiological responses to NMDA and respond to various antagonists selective to the NMDA receptor in the Xenopus oocyte expression system. In addition, a truncated form of the NMDA receptor also exists that contains only the extreme amino-terminal sequence of this protein molecule. These data indicate that the NMDA receptor consists of heterogeneous molecules that differ in the extracellular sequence of the amino- and carboxyl-terminal regions.