Leiomyoma of the lesser omentum: report of a case

The case of a 67-year-old Japanese woman with leiomyoma arising from the lesser omentum is reported herein. Although the patient had no abdominal symptoms, findings of a routine abdominal ultrasound examination suggested a mass between the stomach and the lateral segment of the liver. Subsequent magnetic resonance imaging (MRI) demonstrated a 6-cm well-encapsulated tumor in the lesser omentum, and this was confirmed intraoperatively. Resection of the tumor was performed without any other procedure and the histological diagnosis was confirmed as leiomyoma. The patient has been well for the 6 months since her operation. To our knowledge, this is the first report in the English literature of leiomyoma arising from the lesser omentum.

Trace element accumulation in Baikal seal (Phoca sibirica) from the Lake Baikal

Trace element concentrations (Fe, Mn, Zn, Cu, Pb, Ni, Cd, Co and Hg) were determined in 60 Baikal seals and in fishes collected from Lake Baikal in 1992. Low levels of Hg and Cd were found in Baikal seals in comparison with those of marine mammals and it was due to their low concentrations in dietary fish. These results suggest that pollution by Hg and Cd was low in Lake Baikal and these toxic elements were unlikely to be the causative factors for mass mortality of Baikal seal in 1987-1988. Significant correlation of Hg concentration between hair and internal tissues suggested the use of hair for Hg monitoring in pinnipeds. Among essential elements, higher Fe and lower Cu levels were specifically found in the liver of Baikal seal. The noticeable accumulation of essential elements might be related to the unique and specific environment of Lake Baikal.

Classification of hematopoietic regions in out-of-phase T1-weighted images: a quantitative comparison study with T1-weighted and STIR images

The hematopoietic regions were classified into two groups on the basis of out-of-phase T1-weighted images (op-T1WI): regions with lower intensity than that of muscle (LH) and regions with intensity equal to or higher than that of muscle (HH). We quantitatively evaluated the differences in signal intensity between LH and HH in order to examine this classification. Forty-two hematopoietic areas in aplastic anemia were classified into two groups of 23 LH and 19 HH. The signal ratios of hematopoietic areas to muscle on T1WI and STIR were calculated, and the differences between LH and HH were statistically evaluated. The signal ratios of LH were significantly higher on T1WI and lower on STIR than those of HH (unpaired t-test, p < 0.05). This result indicated that LH consisted of more hypocellular marrow than HH. Op-T1WI were useful in differentiating between LH and HH and defining the degree of hematopoiesis in aplastic anemia.

The attenuation of suppression of motility by triazolam in the conditioned fear stress task is exacerbated by ethanol in mice

We investigated whether triazolam attenuated the suppression of motility in the conditioned fear stress task in mice and whether ethanol modified the effects of triazolam. When mice were placed 24 hours later (retention test) in the same environment in which they had previously been exposed to an electric foot shock (training), they exhibited a marked suppression of motility (conditioned fear stress). Triazolam (0.01-0.1 mg/kg, s.c.), administered before training, attenuated the suppression of motility in the conditioned fear stress task in a dose-dependent manner, without affecting the sensitivity to an electric foot shock. The doses of triazolam that attenuated the suppression of motility were much lower that those of chlordiazepoxide (5-10 mg/kg, s.c.). Neither drug, administered before the retention test, attenuated the suppression of motility in the conditioned fear stress task. These results suggest that both benzodiazepines may inhibit the process of acquisition, but not the process of recall, of memory. Ethanol (1 g/kg, p.o.), which, by itself, did not affect either the suppression of motility or the sensitivity to an electric foot shock, exacerbated the attenuation of the suppression of motility in the conditioned fear stress task induced by both triazolam (0.01 mg/kg) and chlordiazepoxide (5 mg/kg). These results suggest that ethanol exacerbates the effects of benzodiazepines.

Salmon GnRH synthesis in the preoptic area and the ventral telencephalon is activated during gonadal maturation in female Masu Salmon

Changes in salmon gonadotropin-releasing hormone (sGnRH) synthetic activity in the brain during gonadal maturation were examined by in situ hybridization in 2-year-old female masu salmon. Oncorhynchus masou. During gonadal maturation, the numbers of neurons expressing sGnRH mRNA increased in the preoptic area and the ventral telencephalon, but not in the olfactory bulbs and the terminal nerve ganglion. The numbers of silver grains per neuron also increased in the preoptic area and the ventral telencephalon. These results indicate that sGnRH has multiple physiological functions according to the location of the neurons in the brain; neurons in the preoptic area and the ventral telencephalon are involved in gonadal maturation possibly by stimulating gonadotropin synthesis and release, whereas neurons in the olfactory bulbs and the terminal nerve ganglion may have different roles.

Short photoperiod accelerates preoptic and ventral telencephalic salmon GnRH synthesis and precocious maturation in underyearling male masu salmon

The temporal relationship between testicular maturation and salmon gonadotropin-releasing hormone (sGnRH) mRNA expression was investigated in underyearling precocious male masu salmon, Oncorhynchus masou. Testicular maturation could be experimentally manipulated by changing the length of the light-dark photoperiod; maturation was accelerated in the short photoperiod group (8L-16D) and delayed in the long photoperiod group (16-8D). sGnRH mRNA and total silver grains in these loci in individual fish, increased with advancing testicular maturation. They were maximal in the short photoperiod group in August and in the long photoperiod group in September, when spermiation occurred. In contrast, marked changes in sGnRH synthetic activity in relation to testicular maturation were not observed in the terminal nerve ganglion or in the olfactory bulbs. sGnRH neurons in the preoptic area and the ventral telencephalon are clearly influenced by photoperiod and are involved in the control of gonadal maturation probably via gonadotropin secretion.

Immunocytochemical localization of sGnRH and cGnRH-II in the brain of goldfish, Carassius auratus

The immunocytochemical distribution of salmon gonadotropin-releasing hormone (sGnRH) and chicken GnRH-II (cGnRH-II) neurons in the brain of goldfish was examined using respective antisera. Salmon GnRH-immunoreactive (ir) cell bodies were localized in the area between the olfactory nerve and the olfactory bulb (the terminal nerve ganglion), the ventral telencephalon, the preoptic area, and the hypothalamus. Chicken GnRH-II-ir cell bodies were observed in the same areas as were those of sGnRH, although the number of cell bodies were fewer than those of sGnRH. In addition, chicken GnRH-II-ir cell bodies were also observed in the midbrain tegmentum where no sGnRH-ir cell bodies were found. Both sGnRH-ir and cGnRH-II-ir fibers were distributed not only in the hypothalamus and the pituitary gland but also in various brain areas from the olfactory bulb to the spinal cord. The wide distribution of GnRH-ir fibers suggests that in the goldfish, sGnRH and cGnRH-II not only regulate gonadotropin release from the pituitary gland but also function as neuromodulators in various brain regions.

Multiple gonadotropin-releasing hormone (GnRH)-immunoreactive systems in the brain of the dwarf gourami, Colisa lalia: immunohistochemistry and radioimmunoassay

The present study characterizes gonadotropin-releasing hormone (GnRH) neuronal groups that are located in several different brain regions by investigating GnRH molecular species and projection patterns in an anabantid fish, Colisa lalia. First, we examined the molecular species of GnRHs in extracts of the brain and the pituitary by reverse-phase high-performance liquid chromatography followed by radioimmunoassays. We found salmon GnRH (sGnRH), chicken GnRH-II (cGnRH-II), and an unfamiliar GnRH-like substance. Next, to examine the distribution of each GnRH molecule in different GnRH neuronal groups, we performed immunohistochemistry using four kinds of antisera and an antibody. Furthermore, we performed brain lesioning experiments of terminal nerve (TN) cells, the most conspicuous GnRH-immunoreactive cells in Colisa lalia. Comparisons of immunoreactive structures between TN-lesioned fish and untreated fish elucidated the projection area of each neuronal group. Three major neuronal groups were observed. TN-GnRH cells, which are located in the transitional area between the olfactory bulb and the telencephalon, showed strong sGnRH and weaker cGnRH-II immunoreactivity. TN-GnRH cells projected to wide areas of the central nervous system from the olfactory bulb to the spinal cord. The second group, located in the preoptic area, showed only sGnRH immunoreactivity and projected only to the pituitary. The third one, located in the midbrain tegmentum, exhibited strong cGnRH-II and weaker sGnRH immunoreactivity. This cell group projected mainly to brain regions posterior to the hypothalamus and the spinal cord. These different projection patterns suggest functional differentiation of each GnRH neuronal group.

Long-term effects of simvastatin in hypercholesterolemic patients with NIDDM and additional atherosclerotic risk factors. Hyogo Simvastatin Study Group

Effects of 12 months of simvastatin treatment were examined in 48 NIDDM patients with total serum cholesterol levels exceeding 220 mg/dl and were compared with those in 35 nondiabetic patients with hypercholesterolemia. In the diabetic group, 5-10 mg of simvastatin given once daily at bedtime significantly lowered total cholesterol (21%). LDL cholesterol (28%), apoB (15%) and triglycerides (8%) levels. These changes were identical to those in the nondiabetic group, except for triglycerides which did not change significantly. HDL cholesterol increased significantly in the nondiabetic group but not in the diabetic group. The reductions in LDL cholesterol and apoB in hypercholesterolemic patients with NIDDM were not influenced by gender, age, glycemic control, the presence or absence of systemic hypertension, obesity and overt proteinuria. In addition, the decrease in LDL cholesterol was not affected by the number of risk factors per patient. Simvastatin did not significantly alter hemoglobin A1c or fasting plasma glucose and was well tolerated in both groups. Simvastatin produced beneficial effects on serum lipids and apolipoproteins and neutral effects on glycemic control in hypercholesterolemic patients with NIDDM, whether or not they had an additional atherosclerotic risk factor.

Evaluation of the performance of a whole-body positron imaging system with attenuation correction

A PET scanner with ring detectors has been modified to accomplish whole-body imaging with attenuation correction. To evaluate the performance of this system, phantom studies and clinical studies were performed in seven patients. The transaxial resolution (FWHM) at the center of the field was 8.6 mm, and the axial resolution was 12.3 mm. The counts on the images with attenuation correction were linearly related to accumulation of the radiopharmaceuticals, and attenuation correction was made accurately. The transmission scan from the top of the head to the thigh, about 110 cm in length, required 36 minutes, and one emission scan required 18 minutes. The total study time for one transmission scan and three sequential emission scans was 1.9 hours. In clinical studies, attenuation correction made the discrimination of organs clearer, and would facilitate the detection of tumors, especially those in the high attenuation organs or matter. The use of this system made it possible to obtain quantitative whole-body positron images with adequate diagnostic quality within a reasonable scanning time.

Scintigraphic detection of recurrence of medullary thyroid cancer

A case of recurrent medullary thyroid cancer (MTC) was evaluated with 123I-MIBG, 99mTc(V)-dimercaptosuccinic acid (DMSA), and 201Tl scintigraphy. This patient had been operated on for MTC in the right thyroid. Recently a left neck mass was noticed, and was suspected of being a recurrence of MTC based on increased plasma calcitonin (CT) and carcinoembryonic antigen (CEA). He was operated on for the neck mass which revealed MTC, and papillary thyroid cancer was incidentally found in the left thyroid, but the CT and CEA levels remained high, and remaining MTC tumor was suspected. But the location of the tumor was unknown. Although 99mTc(V)-DMSA scintigraphy is generally believed to be superior in sensitivity to 123I-MIBG scintigraphy, it did not demonstrate the tumor site but 201Tl and 123I-MIBG did. Furthermore, 123I-MIBG scintigraphy has greater specificity for tumors which arise in the neural crest. Judging from the results of this case and cases reported in the literatures, both 123I-MIBG and 99mTc(V)-DMSA should be performed in the detection of recurrent MTC.

8-OH-DPAT-induced hypotensive action and sympathoexcitatory neurons in the rostral ventrolateral medulla of the rat

We examined whether the selective 5-hydroxytryptamine 1A (5-HT1A) receptor agonist 8-hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT) injected systemically can act directly on sympathoexcitatory neurons located in the rostral ventrolateral medulla (RVLM) to cause the hypotensive effect of this agent in rats. Microinjections of 8-OH-DPAT and buspirone into the RVLM produced a dose-dependent decrease in blood pressure. Microinjections of spiperone and pindolol, 5-HT1A antagonists, into the RVLM inhibited the depressor response to 8-OH-DPAT intravenously injected or injected into the RVLM. Microiontophoretic application of 8-OH-DPAT onto RVLM sympathoexcitatory neurons inhibited the firing of RVLM sympathoexcitatory neurons and the inhibition of unit activity by 8-OH-DPAT was blocked by microiontophoretic spiperone. Intravenous administration of 8-OH-DPAT also inhibited the firing of these neurons. Microiontophoretic application of spiperone onto the RVLM sympathoexcitatory neurons reversed the inhibitory response to intravenous 8-OH-DPAT. These results are consistent with the hypothesis that 8-OH-DPAT may exert a portion of its hypotensive effect through a direct inhibition of RVLM sympathoexcitatory neurons in rats. The receptor involved is probably the 5-HT1A type.

Effect of real-time weighted integration system for rapid calculation of functional images in clinical positron emission tomography

A system has been developed to rapidly calculate images of parametric rate constants, without acquiring dynamic frame data for clinical positron emission tomography (PET). This method is based on the weighted-integration algorithms for the two- and three-compartment models, and hardware developments (real-time operation and a large cache memory system) in a PET scanner, Headtome-IV, which enables the acquisition of multiple sinograms with independent weight integration functions. Following the administration of the radiotracer, the scan is initiated to collect multiple time-weighted, integrated sinograms with three different weight functions. These sinograms are reconstructed and the images, with the arterial blood data, are inserted into the operational equations to provide parametric rate constant images. The implementation of this method has been checked in H(2)(15 )O and (18)F-fluorophenylalanine ((18)FPhe) studies based on a two-compartment model, and in a (18)F-fluorodeoxyglucose ((18)FDG) study based on the three-compartment model. A volunteer study, completed for each compound, yielded results consistent with those produced by existing nonlinear fitting methods. Thus, this system has been developed capable of generating rapidly quantitative, physiological images, without dynamic data acquisition, which will be of great advantage to PET in the clinical environment. This system would also be of great advantage in the new generation high-resolution PET tomography, which acquire data in a 3-D, septaless mode.

Differential inhibition of platelet aggregation and calcium mobilization by nitroglycerin and stabilized nitric oxide

We compared the mechanisms of the antiplatelet effects of nitroglycerin (NTG) and stabilized nitric oxide (NO). Stabilized NO was in the form of S-nitrosothiols [S-nitroso-albumin (S-NO-Alb) and S-nitrosocaptopril (S-NO-Cap)] or heme-NO [sodium nitro-prusside (SNP)]. The molecular structure of S-NO-Cap was confirmed by mass spectrometry. NTG, SNP, S-NO-Alb, and S-NO-Cap inhibited ADP-induced platelet aggregation dose dependently. The inhibitory IC50 value was 109 microM for NTG, 0.98 microM for SNP, 2.99 microM for S-NO-Alb, and 2.5 microM for S-NO-Cap. NTG (200 microM) released 15.4 microM nitrite anion into platelet-rich plasma (PRP) after 60-min incubation, to which platelets contributed 5.4 microM. On the other hand, SNP and S-NO-Cap released undetectable amounts of NO2- when incubated in either PRP or platelet-poor plasma (PPP). The platelet cytosolic calcium ion (Ca2+) concentration was measured fluorometrically in Fura-2-loaded gel-filtered platelets. Thrombin-induced Ca2+ mobilization was significantly inhibited by 10 microM NTG, SNP, S-NO-Alb, and S-NO-Cap, whereas resting Ca2+ was unaltered. Ca2+ mobilization was inhibited 28.6% by NTG, 91.9% by SNP, 90.0% by S-NO-Alb, and 92.7% by S-NO-Cap. These results demonstrate that NTG is an exogenous donor of NO, but releases it only slowly. On the other hand, SNP and S-nitrosothiols inhibited platelet aggregation by the action of stabilized NO incorporated in their structure and did not release NO. NTG and stabilized NO shared a common mechanism of antiplatelet activity, which involved inhibition of calcium mobilization.

Pigmentary retinopathy with nephrotic syndrome, Ménétrier's disease, and diabetes mellitus

A patient with pigmentary retinopathy, nephrotic syndrome, Ménétrier's disease, and diabetes mellitus is presented. Other complications were congestive heart failure, hypothyroidism, hypertension, and hypertriglyceridemia. Hypogenitalism was also suspected. Pigmentary retinopathy is known to associate with many systemic diseases, which are classified into several syndromes. This case superficially resembles Alström's disease due to the common characteristics of pigmentary retinopathy, diabetes mellitus, renal disease, and hypogenitalism. But clinically and histologically, there are distinct differences. To our knowledge, this association has never been reported.

Salmon gonadotropin-releasing hormone and gonadotropin are involved in precocious maturation induced by photoperiod manipulation in underyearling male masu salmon, Oncorhynchus masou

The relationship between gonadal maturation, salmon gonadotropin-releasing hormone (sGnRH), and gonadotropin (GTH) subunit contents in the brain and pituitary was investigated in underyearling masu salmon, Oncorhynchus masou. Gonadal maturation was manipulated by changing photoperiod to examine the involvement of these hormones in this process. Fish were divided into short (8 hr L: 16 hr D) and long photoperiod (16 hr L:8 hr D) groups in mid-June and maintained for 4 months until October. Gonadal maturation occurred in most males (precocious males), while a few remaining males and all females did not mature throughout the experiment irrespective of photoperiodic group. In precocious males, pituitary contents of sGnRH, GTH I beta, and GTH II beta increased faster under short photoperiod than under long photoperiod, and spermiation was observed in August. Under long photoperiod, these hormones gradually increased until October when spermiation occurred. sGnRH concentrations in the telencephalon of precocious males were high when spermiation occurred; in August, they were higher in the short photoperiod than in the long photoperiod group; in October, they were higher in the long photoperiod group. The increases of sGnRH and GTH in the pituitary and sGnRH in the brain appear to be involved in precocious maturation inducible by manipulation of photoperiod.

Activation of salmon gonadotropin-releasing hormone synthesis by 17 alpha-methyltestosterone administration in yearling masu salmon, Oncorhynchus masou

Juvenile salmonid pituitary gonadotropin (GTH) contents are elevated after steroid hormone treatment, but the involvement of gonadotropin-releasing hormone (GnRH) is unclear. Activation of salmon GnRH (sGnRH) synthesis by 17 alpha-methyltestosterone (MT) administration has been examined in the brain of yearling masu salmon (future precocious males and immature females) using an in situ hybridization technique combined with radioimmunoassay. Oral MT application markedly increased pituitary GTH II beta, but not GTH I beta, contents in both sexes. In future precocious males, MT treatment increased the number of cells expressing sGnRH mRNA in the preoptic area about threefold, whereas there were no significant differences in the olfactory bulbs and the ventral telencephalon. No significant changes were observed in cell sizes nor the numbers of silver grain per 100 microns2 cell in any of the brain regions. Thus, in future precocious males, preoptic sGnRH neurons may be activated by sex steroids. In contrast, no significant changes were observed in sGnRH mRNA levels of immature females after MT treatment. These differences in responses to sex steroids of sGnRH cells in the preoptic area between future precocious males and immature females suggest that MT has indirect actions via sGnRH and/or direct actions on the pituitary in the former, and that MT acts directly on the pituitary in the latter.

Gonadotropin-releasing hormones of terminal nerve origin are not essential to ovarian development and ovulation in goldfish

The involvement of gonadotropin-releasing hormones (GnRHs) from the terminal nerve (TN) in ovarian development and ovulation was examined by olfactory tract section (OTX) in goldfish. After OTX, brain contents of salmon GnRH (sGnRH) and chicken GnRH-II (cGnRH-II) were measured by specific radioimmunoassays. Olfactory tracts of sexually maturing females were sectioned prior to the spawning season and were kept under natural conditions. Two months later, brain sGnRH contents markedly decreased in all brain areas (telencephalon, hypothalamus, optic tectum-thalamus, cerebellum, medulla oblongata) except in the olfactory bulbs, whereas cGnRH-II contents did not obviously change. Despite the large decreases in brain sGnRH contents, OTX and sham-operated female fish underwent vitellogenesis. Sexually mature OTX females could be stimulated to ovulate by increased water temperatures during spawning season. Brain sGnRH contents of these OTX fish also markedly decreased with no changes in cGnRH-II. It appears that sGnRH of TN origin, which comprises most of the brain sGnRH in the goldfish, is not a prerequisite for basal gonadotropin secretion and ovarian development, and is not likely to be related to the preovulatory gonadotropin surge which stimulates ovulation in goldfish.

[CD7 positive undifferenciated leukemia/lymphoma associated with leukemic pericarditis]

We report here a CD7 positive undifferenciated leukemia/lymphoma which showed a rapid clinical course. A 27-year-old female was complained of palpitation and edema. She had a mediastinal tumor and pericardial effusion. Lymphoblastic cells were found in the effusion, but in the peripheral blood initially. After admission the blast cells appeared in the peripheral blood, and they were revealed negative for peroxidase and had phenotype of CD7 and CD33 positive. The patient suffered from cardiac tamponade and died 15 days after admission. The Southern blotting of mediastinal tumor cells disclosed the germline configuration for TCR-beta a chain and the rearrangement of immunoglobulin heavy chain genes.

Cytokine synthesis and apoptosis by intestinal intraepithelial lymphocytes: signaling of high density alpha beta T cell receptor+ and gamma delta T cell receptor+ T cells via T cell receptor-CD3 complex results in interferon-gamma and interleukin-5 production, while low density T cells undergo DNA fragmentation

To study the biological consequences of cytokine production and apoptosis by intraepithelial lymphocytes (IEL), we have studied these characteristics in both the high and low density CD3+ IEL populations. Stimulation of low- or high-density CD3+ IEL via the T cell receptor (TCR)-CD3 complex using monoclonal anti-CD3, anti-alpha beta TCR or anti-gamma delta TCR antibodies resulted in opposing effects. In one case, a significant number of the high-density CD3+ T cells entered cell cycle from the resting stage (DNA replication was observed) and anti-TCR-CD3 treatment enhanced the numbers of interferon-gamma and interleukin-5 spot-forming cells in this cell fraction. In contrast, when the low-density alpha beta TCR+ or gamma delta TCR+ T cells were activated via the TCR-CD3 complex, DNA fragmentation was observed. These results demonstrated that the activation signals transduced via the TCR-CD3 complex resulted in their entry into the cell cycle and subsequent interferon-gamma and interleukin-5 production in the high-density IEL T cell subset. However, identical signals induced apoptosis in the majority of the low-density fraction of CD3+ IEL.

Excitatory amino acid receptors in the rostral ventrolateral medulla mediate hypertension induced by carotid body chemoreceptor stimulation

The rostral ventrolateral medulla (RVLM) is involved in the mediation of cardiovascular responses to peripheral chemoreceptor stimulation. To investigate whether excitatory amino acid inputs in the RVLM are related to the responses to chemoreceptor stimulation, we microinjected kynurenate, an amino acid antagonist, unilaterally into the RVLM and examined its effects on the pressor response to stimulation of carotid body chemoreceptors. Male Wistar rats were anesthetized with urethane, paralyzed and artificially ventilated. The carotid chemoreceptors were stimulated with isotonic solutions of inorganic phosphate solution. Stimulation of carotid body chemoreceptors produced increases in blood pressure. Kynurenate injected ipsilaterally but not contralaterally into the RVLM markedly inhibited the pressor response to chemoreceptor stimulation. In rats with spinal transection, stimulation of carotid body chemoreceptors also produced increases in blood pressure. The pressor response in rats with spinal transection was inhibited by intravenous injection of a vasopressin antagonist or by kynurenate injected ipsilaterally into the RVLM. Kynurenate injected into the RVLM inhibited the pressor response to NMDA, AMPA and kainate but not to acetylcholine in intact rats. These findings indicate that excitatory amino acid receptors are involved in mediating the pressor response to carotid body chemoreceptor stimulation in the rat RVLM. It appears that the chemoreceptor stimulation produces an increase in vasopressin release and the enhancement of vasopressin release is also mediated by an increase in excitatory amino acid inputs in the RVLM.