Co-occurrence of mucoepidermoid carcinoma and squamous cell carcinoma of the esophagus: report of a case.

A case of co-occurrence of a mucoepidermoid carcinoma (MEC) and a squamous cell carcinoma (SCC) in the esophagus is described. The present patient was a 61-year-old man who underwent a curative esophagectomy with a regional lymph node dissection for a MEC in the lower esophagus and a SCC near the esophagogastric junction. The two lesions were endoscopically and histologically divided by a normal esophageal mucosa. The MEC of the esophagus consisted of SCC cells and signet-ring cells, and a mucin product and carcinoembryonic antigen, which were found at high levels in the blood serum before surgery, were detected histochemically in the signet-ring cells. The follow-up survey of the patients with esophageal MEC previously reported in Japan showed that most of the patients died of either local recurrence or widespread metastasis after treatment; the overall 5-year survival rate was 24.4% in the total 25 cases, and 27.7% in the 22 resected cases. However, 6 patients who died of therapeutic complications were included among these patients; furthermore, the 5-year survival rate after surgery was 29.2% in the patients treated over the last decade (1989-1998). We expect that the clinical outcome of patients treated for esophageal MEC will therefore improve in the future.

Decreased expression of the mRNA for somatostatin in the periventricular nucleus of depression-model rats.

Expression of the mRNA for somatostatin (SRIF) in the periventricular nucleus (PeN), the level of SRIF in the stalk-median eminence (SME) and the concentration of growth hormone (GH) in the plasma were examined in depression-model rats in an attempt to confirm the hypothesis that SRIF neurons in the hypothalamus are hypofunctional in this model. We exposed male Wistar rats to intermittent walking stress for two weeks and then we measured their spontaneous running activity for 12 days. We divided the rats into a depression-model group and a partial-recovery group according to the spontaneous running activity of each rat after the termination of exposure to stress. Expression of SRIF mRNA in the PeN of the hypothalamus was monitored by in situ hybridization and relative levels were determined with an image analysis system. The relative level of expression of SRIF mRNA in the PeN was lower in rats in the depression-model group than in the control group and the partial-recovery group. The level of SRIF in the SME was lower and the plasma concentration of GH was higher in the depression-model group than in the other groups. Our findings suggest that reduced expression of mRNA for SRIF in the PeN might be associated with the pathophysiology of rats with this particular model of depression.

Increased expression of magnocellular arginine vasopressin mRNA in paraventricular nucleus of stress-induced depression-model rats.

Exposure of rats to long-term intermittent walking stress results in a persistent inactive behavior in the subsequent two weeks in about 50% of rats (depression-model rats) while the activity returns gradually toward baseline in other rats (spontaneous recovery rats). To explore the role of hypothalamic-pituitary-adrenal (HPA) axis in these depression-model rats, we examined changes in the gene expression of corticotropin-releasing factor (CRF) and arginine vasopressin (AVP) in the paraventricular nucleus (PVN) of the hypothalamus using in situ hybridization histochemistry. We imposed the intermittent walking stress for two weeks in male Wistar rats, then compared the response of the depression-model rats and spontaneous recovery rats. The expression of CRF mRNA in PVN increased significantly by 60% and 80% compared to controls, in the model and the recovery rats, respectively. The magnocellular AVP mRNA in PVN increased significantly in the model rats by 60% compared to controls. The concentration of plasma ACTH increased in the model rats, but no significant change in plasma corticosterone or AVP level was noted in all three groups. Our results suggest that increased magnocellular AVP in PVN plays an important role in the regulation of HPA axis of the depression-model rats induced by long-term walking stress.

Enhanced response of growth hormone to growth hormone-releasing hormone and a decreased content of hypothalamic somatostatin in a stress-induced rat model of depression.

This study was designed to evaluate changes in the hypothalamic somatostatin-growth hormone axis (SRIF-GH axis) in a stress-induced rat model of depression. We exposed male Wistar rats to intermittent walking stress for two weeks, and then measured their spontaneous running activities for 12 days. We divided the rats into the depression-model group and the partial recovery group according to their spontaneous running activities after the termination of exposure to stress. We examined the secretion of GH from the anterior pituitary by injecting human GH-releasing hormone (hGHRH) with intracardiac cannulae or by applying hGHRH or SRIF to isolated anterior pituitaries using a perifusion system. We also determined SRIF content in the stalk-median eminence (SME) and the plasma concentration of GH. In the depression-model group, intracardiac administration of hGHRH caused the enhanced release of GH into plasma, while application of hGHRH or SRIF to the anterior pituitary in vitro had similar effects on GH release in the control and partial recovery groups. Furthermore, the SRIF content was decreased in the SME and the GH concentration was increased in plasma. The partial recovery group gave similar values to the control group. The enhanced response of GH to hGHRH in the depression-model group might have been caused by the reduced content of SRIF in the SME in view of the unchanged response of GH to the infusion of hGHRH or SRIF in the perifusion system.

Effect of reserpine on 3-methoxy-4-hydroxyphenylethyleneglycol and 3,4-dihydroxyphenylacetic acid in the hippocampus of depression-model rats: an in vivo microdialysis study.

Using in vivo microdialysis, we examined the effect of intraperitoneal injection of reserpine (2 mg/kg) on hippocampal 3-methoxy-4-hydroxyphenylethyleneglycol (MHPG) and 3,4-dihydroxy-phenylacetic acid (DOPAC), two major metabolites of catecholamine. Responses were examined serially for 12 h in the hippocampus of walking-stress-induced depression-model rats, recovery rats and control rats. Control rats showed a rapid rise followed by a gradual fall of free and total MHPG and a delayed increase of DOPAC in response to reserpine. Depression-model rats showed a significantly blunted biphasic response of free and total MHPG as well as blunted monophasic response of DOPAC compared with control rats. Recovery rats also exhibited a blunted fall response of MHPG. Our findings suggest that the vesicle membrane in the central noradrenaline (NA) neurons could be hyposensitive to reserpine in the depression-model rats.

Impaired endothelial function in epicardial coronary arteries after Kawasaki disease.

BACKGROUND: Intimal lesions observed in the coronary arteries (CAs) of patients who have suffered episodes of Kawasaki disease (KD) raise concern about the premature development of arteriosclerosis. Accordingly, we investigated endothelial function in the epicardial and resistance CAs after KD during long-term observation. METHODS AND RESULTS: We assessed the responses of left epicardial and resistance CAs to serial intracoronary infusions of acetylcholine (final concentrations, 0.1 and 1 micromol/L) and nitroglycerin in subjects by using quantitative angiography and a Doppler flow wire system. Three age-matched groups were evaluated: 8 control subjects (group 1), 10 KD patients with normal left CA from the onset (group 2), and 8 KD patients with a persistent or regressed aneurysm in the left anterior descending CA (LAD) (group 3). Acetylcholine (1 micromol/L) changed the LAD area to 114.0+/-2.6%, 72.7+/-3.9% (P<.05 versus group 1), and 88.9+/-4.3% (P<.05 versus groups 1 and 2) of baseline in groups 1, 2, and 3, respectively, with a similar degree of increased coronary blood flow in each group. Nitroglycerin increased the LAD area to 143.5+/-7.7%, 132.3+/-1.9%, and 120.8+/-5.6% (P<.05 versus group 1), respectively. CONCLUSIONS: Results demonstrate a persistent endothelial dysfunction in the epicardial but not resistance CAs in patients after KD and enhanced stiffness of persistent or regressed aneurysms. The concern over early arteriosclerosis warrants the surveillance of KD patients from childhood to adulthood.

Why is cyclooxygenase-2 expressed in neuroendocrine cells of the human alimentary tract?

During immunohistochemical studies of cyclooxygenase-2 (COX-2) on human colon cancers, many strong COX-2-immunoreactive cells scattered in the bottom of the crypt of normal colon mucosa were unexpectedly noticed. COX-2-immunoreactive cells were morphologically very similar to neuroendocrine cells and were confirmed immunohistochemically to be positive for chromogranin A or serotonin. Moreover, COX-2-immunoreactive neuroendocrine cells were observed not only in the large intestine, but also in the stomach, duodenum and small intestine. The role of COX-2 expression in neuroendocrine cells of the human alimentary tract was speculated.

Optical bus interconnection system using Selfoc lenses.

A novel optical bus interconnection system that uses Selfoc lenses is proposed. The technique can be categorized as one of free-space interconnects, and it has the potential to overcome the problems associated with the free-space optical system, such as difficulties of achieving precise assembling, compact mounting, and high durability. Its concept, fabrication techniques, features, and possible applications are discussed, along with an experimental result.

[Relation between articulatory function and prosthesis. I-1. Longitudinal changing aspects in the duration of speech sound, muscular discharge of facial muscle and tongue pressure before pronunciation caused by the experimental palatal plate].

The author noticed the relation between articulatory functions and the prosthesis. For the purpose of clarifying the influence of the insertion of denture on the duration of speech sound and the articulatory functions before pronunciation and on the self-compensation of these organs. The experimental palatal plates were inserted on 13 subjects with natural dentition, assuming that they were inserted with complete denture, and the duration of speech sound, muscular discharge of facial muscle and tongue pressure before pronunciation were evaluated longitudinally with the pre-insertion of palatal plate as basis. As the result of this study, the following conclusions were obtained. The results of this study suggest that speech sound, lips and tongue being important organs as the articulators are placed under strong influence before pronunciation by insertion of the denture, whereas on the self-compensation of the articulators before pronunciation differed according to the point of articulation and the manner of articulation of each speech sound. Therefore, it was necessary to take care on the relation between the shape of palatal plate and the articulatory functions of lips and tongue in the clinical prosthodontics.

Multiple imaging and multiple Fourier transformation using planar microlens arrays.

A new type of multiple imaging and multiple Fourier transformation system under coherent illumination using microlens arrays has been developed. The optical system is based on geometrical optics instead of convolution or diffraction. As a result, it has the advantage of design flexibility especially in alignment of the duplicate images. The experimental results of the system, which are implemented using planar microlens arrays fabricated by an ion exchange technique, are also discussed.

High numerical aperture planar microlens with swelled structure.

The planar microlens is a 2-D integrated microlens fabricated by the selective ion exchange technique. This paper demonstrates a new class of planar microlens which has a high numerical aperture. The new planar microlens uses a swelling structure and index distribution which comes from replacing ions with different ion volumes. Lens diameters from 10 to 400 microm can be fabricated. A numerical aperture larger than 0.5 is achieved when the lens diameter is smaller than 100 microm. Use of this microlens in light coupling between an LD and a single-mode fiber is also evaluated.

Optical implementation of an associative neural network model with a stochastic process.

An optical associative neural network with a stochastic thresholding procedure has been demonstrated. The use of stochastic processing drastically improved the convergence rate into the correct global minima (recognition rate). The properties of undesirable spurious minima were also investigated. It was found that the spurious minima were represented as the mixed states of the stored vectors. A useful method to estimate the required noise level to vanish the spurious minima is described.

Fiber-optic passive ring-resonator gyroscope using an external-cavity laser diode.

We report a fiber-optic passive ring-resonator gyroscope that uses an external-cavity laser diode. The external-cavity laser diode is useful as the light source for the gyroscope if an appropriate cavity length is chosen. A rotation detection sensitivity of 10(-2) rad/sec was obtained with an integration time of 10 sec.

Effect of reflections on the drift characteristics of a fiber-optic passive ring-resonator gyro.

We show the effect of reflections at the fiber ends on the drift characteristics of a fiber-optic passive ring-resonator gyro. A rotation-detection sensitivity as low as 3 x 10(-5) rad/sec (tau = 30 sec) was obtained by reducing the effect of reflected lights with an optical phase modulator.