The effect of clonidine on the activity of neurons in the rat dorsal raphe nucleus in vitro

The dorsal raphe (DR) nucleus is a system of nuclei in the midline of the lower brainstem, which is considered one of the most important nuclei in the modulation of pain in the central nervous system. Central noradrenergic systems play an important role in the control of cardiovascular regulation and pain transmission. Clonidine, an alpha 2-adrenergic agonist is used extensively in anesthesia research. In this study, we evaluated the involvement of clonidine in the activity of DR nucleus and its possible role in pain modulation. Seventy-four neurons within the DR nucleus in the rat brainstem slice preparation were tested using extracellular recording techniques. Application of noradrenaline (NA), 50 mumol/L, induced firing activity in 68 neurons tested (92%). NA produced a regular long-lasting firing activity on the DR neurons. Fifty-six neurons (88%) previously excited by NA were inhibited by clonidine, 20 mumol/L. Clonidine suppressed the firing activity of neurons. The results indicate that the firing of DR neurons was under noradrenergic influence and was inhibited by clonidine, which in turn alters nociception by modifying the central serotonergic system.

Effect of antiandrogen treatment on chemical hepatocarcinogenesis in rats

We studied the effect of antiandrogen treatment on the Solt-Farber model of hepatocarcinogenesis in male Sprague-Dawley rats. The size and number of the liver tumors were reduced by various antiandrogen treatments (orchiectomy, an LH-RH analog, and chlormadinone acetate). In addition, the proportion of poorly differentiated carcinomas was decreased by the antiandrogen treatment, while that of well-differentiated trabecular or glandular carcinomas was increased. The bromodeoxyuridine labeling index of the tumor cells was significantly decreased after the antiandrogen treatment. The expression of rat androgen receptor mRNA in carcinoma tissue was increased when compared to control liver tissue, and was decreased after the antiandrogen treatment. Orchiectomy had the greatest inhibitory effect on carcinoma, although the effect of chemical orchiectomy using an LH-RH analog was almost similar to that of orchiectomy. These results suggest that the clinical application of antiandrogen therapy for human hepatocellular carcinoma might be possible in the future.

Distribution of pulmonary blood flow in conscious resting rats

The pattern of pulmonary blood flow (PBF) distribution was determined in the rat, in which lung gravitational forces are minimal. Microspheres were infused into the inferior vena cava of 15 conscious, and 5 anesthetized rats. Relative scatter of specific PBF [(sample activity/sample weight)/(total activity/total weight)] in 28 lung samples was calculated. In 5 of the conscious rats, consecutive determinations were made 30 min apart. In 5 anesthetized rats, PBF was determined in prone and supine positions. Relative scatter of specific PBF varied from 0.84 to 1.12, with PBF being distributed preferentially to the hilar, central regions. There was a high correlation between consecutive measurements: y = 0.88 x +0.11 (n = 140, r = 0.92). By changing from prone to supine position, PBF to the topmost regions increased, and that to the lowermost regions decreased, by only 3 percent. The results indicate that in the conscious resting rat, PBF has a small but significant preferential distribution to the hilar, central regions, with lower blood flow to the peripheral regions of the lung.

Some personal comments on the Sydney system for the classification of chronic gastritis

The Sydney system for the classification of chronic gastritis is a system for describing the histopathological findings of a biopsy specimen. It involves the analysis of two to four biopsies of the gastric mucosa taken from arbitrary sites, which, taken alone, are insufficient for extrapolation to the diagnosis of the whole stomach. The system seems to be useful as a computer-oriented method fo documenting the histopathological analysis of the two to four biopsy specimens obtained from the arbitrary sites in the antrum or corpus. One biopsy specimen is obtained from the anterior wall of the antrum, the other from the posterior wall. They would be better obtained from the lesser and greater curvatures, which areas would provide more accurate data concerning the antrum or body. While this may be invaluable for researchers with particular interests, it is quite valueless for the majority of clinicians who must diagnose and treat their patients. When a classification is made, its purposes should, firstly, be clear and definite. Secondly, the classification should be simple and easy to use. If a classification is effective, it will be widely used. However, in this field, it is almost impossible to achieve a classification that will fully satisfy all practitioners and researchers with different interests. The Sydney system alone is not sufficient for the classification of chronic gastritis. It is merely a system for describing the histopathological findings of biopsy specimens. It does not allow for an integrated diagnosis of chronic gastritis of the entire stomach.

Sonographic features of colon carcinoma seen with high-frequency transabdominal ultrasound

To assess the value of high-frequency ultrasonography as a diagnostic imaging procedure in patients with colon carcinoma, we first evaluated the sonograms of 37 patients who had been already diagnosed with contrast enema and/or colonoscopy as having colon carcinoma. As a result, the sonographic criteria for diagnosis of a possible colon carcinoma were (1) a localized and irregular thickening of the colonic wall with heterogenous low echogenicity, (2) an irregular contour, (3) a lack of demonstrable movement or change of configuration of the bowel on real-time scanning, and (4) absence of wall stratification. During the last 4 years, 41 consecutive patients had findings meeting our sonographic criteria. In 37 patients (90%), the presence of colon carcinoma was confirmed by contrast enema and/or colonoscopy. Our study suggests that high-frequency real-time ultrasonography may be a useful imaging technique in diagnosis of colon carcinoma.

Diagnostic usefulness of MR imaging for pedunculated hepatocellular carcinoma

Pedunculated hepatocellular carcinoma (HC) is an uncommon tumor of the liver. We present the case of a 56-year-old man with pedunculated HC arising from the lower surface of the liver. We recommend sagittal magnetic resonance imaging, which offers a superior choice of scanning planes, in the diagnosis of pedunculated HC.

Therapeutic effects of imidapril on cerebral lesions observed by magnetic resonance imaging in malignant stroke-prone spontaneously hypertensive rats

OBJECTIVE

Magnetic resonance imaging (MRI) was used to investigate the therapeutic effects of imidapril, a newly synthesized angiotensin converting enzyme (ACE) inhibitor, on cerebral stroke lesions.

DESIGN

Pretreatment with ACE inhibitors is known to prevent stroke in stroke-prone spontaneously hypertensive rats, prolonging their lifespan. Malignant stroke-prone spontaneously hypertensive rats (M-SHRSP) were treated with imidapril after the onset of stroke.

METHODS

M-SHRSP with proved stroke were divided into two groups. One group received 40 mg/kg per day imidapril and the other group was used as a control. For 4 weeks, neurological symptoms were scored daily, and MRI images were taken and scored once a week.

RESULTS

In the control group the MRI score for cerebral lesions increased during the experiment, and seven out of eight control rats died within 17 days. In rats treated with imidapril the major finding was that imidapril rapidly ameliorated the damage to the blood-brain barrier and resolved brain oedema within 1 week. At the same time the neurological symptoms observed after stroke disappeared. Furthermore, none of the rats treated with imidapril showed recurrence of stroke, and their survival rate was improved.

CONCLUSION

These results suggest that imidapril has therapeutic effects on stroke lesions, as well as prophylactic effects on the recurrence of stroke.

Rotation and membrane topology of genetically expressed methylcholanthrene-inducible cytochrome P-450IA1 lacking the N-terminal hydrophobic segment in yeast microsomes

A modified rat liver cytochrome P-450IA1, lacking amino acids 2-30, a proposed membrane anchor for cytochrome P-450, was expressed genetically in yeast microsomal membranes. This truncated cytochrome is practically active in the deethylation of 7-ethoxycoumarin. A full-length cytochrome P-450IA1 was also expressed in yeast microsomes. Rotational diffusion of P-450IA1 was examined by observing the flash-induced absorption anisotropy r(t) of the P-450.CO complex. The anisotropy decayed to a time-independent value within a 2-ms time range. Since the decay curve has the characteristics of a slow rotation of membrane-embedded cytochrome, the theoretical analysis of r(t) was performed based on a "rotation-about-membrane normal" model. 41% of the shortened P-450IA1 was rotating with the rotational relaxation time phi of 1020 microseconds, whereas 27% of the full-length P-450IA1 was mobile with phi = 1101 microseconds. The high salt treatment did not remove the shortened cytochrome from the membrane and also did not drastically weaken the interactions of the cytochrome with the membrane, as judged from the slow rotation characteristics (phi = 830 microseconds). These results demonstrate that the N-terminal shortened P-450IA1 is incorporated properly into the yeast microsomal membrane and that the N-terminal hydrophobic segment is not solely responsible for attachment to the membrane, providing evidence that additional segments of P-450IA1 are involved in the membrane binding.

Significance of specific antibody assay for genotyping of hepatitis C virus

Group I and II hepatitis C virus genotypes were determined by a newly developed serological genotyping assay. This assay detected antibodies against group-specific recombinant proteins in the putative NS4 protein region (amino acid no. 1676-1760) by an enzyme-linked immunosorbent assay. This region of the hepatitis C virus peptide has many group-specific amino acids; fewer than 50% of these amino acids are identical between groups I and II. Genotypes determined by the serological genotyping assay were compared with those determined by a method in which the polymerase chain reaction was used in 91 chronic hepatitis patients. The group-specific polymerase chain reaction was performed within the genome region corresponding to the putative NS5 protein, where the group II hepatitis C virus genome is 57 nucleotides longer than that of group I. Among 91 chronic hepatitis C patients who had positive results in the second-generation hepatitis C virus antibody (core and NS3 region) assay, hepatitis C virus RNA was detected in 80 patients by polymerase chain reaction in the 5' untranslated region and in 78 patients by this group-specific polymerase chain reaction. As a result, in 76 of 91 patients (84%) genotypes determined by the serological genotyping assay showed complete agreement with those determined by the group-specific polymerase chain reaction, and none of the patients revealed a group opposite to that of hepatitis C virus genotype. The detection rate of the serological genotyping assay (89 of 91; 98%) was even higher than that of the polymerase chain reaction assay (78 of 91; 86%).(ABSTRACT TRUNCATED AT 250 WORDS)

TXK, a novel human tyrosine kinase expressed in T cells shares sequence identity with Tec family kinases and maps to 4p12

A gene for a novel, putative cytoplasmic tyrosine kinase, TXK has been isolated from a human peripheral blood cDNA library. The complete nucleotide sequence of the cDNA indicates that it is related most closely to EMT, a tyrosine kinase of T cells and to the B-cell tyrosine kinase Btk, which is mutated in X-linked agammaglobulinemia (XLA) in humans and X-linked immunodeficiency disease (XID) in mouse. TXK, like BTK, is a member of the Tec sub-family of Src-type (non-receptor) tyrosine kinases. Like similar Tec sub-family members, and unlike the other Src kinases, TXK lacks both the N-terminal myristylation signal and the C-terminal regulatory tyrosine. TXK expression is detected primarily in T cells and some myeloid cell lines but not in a number of other cell types. TXK shares 60% amino acid homology with EMT and 57% with BTK over the SH3, SH2 (Src-homology) and catalytic domains but unlike BTK, EMT and tec, it lacks Gap 1 homology and steroid hormone receptor homology in the N-terminal region. Genomic clones containing TXK have been isolated and hybridize to chromosome position 4p12.

[99mTc-pertechnetate scintigraphy in three cases with soft tissue tumors]

Three soft tissue tumors were studied with 99mTc-pertechnetate scintigraphy, 67Ga-citrate scintigraphy and MRI. These tumors included schwannoma, neurofibromatosis and malignant fibrous histiocytoma. On 99mTc-pertechnetate scintigram all patients showed more increased accumulation corresponding to the tumor than on 67Ga-citrate scintigram. In conclusion, 99mTc-pertechnetate scintigraphy may be useful in detection of soft tissue tumors.

Endothelin ETA receptor antagonist blocks cardiac hypertrophy provoked by hemodynamic overload

BACKGROUND

We have recently shown that angiotensin II-induced hypertrophy of cultured rat cardiomyocytes was partially blocked by an endothelin (ET) receptor antagonist (BQ123) selective for the ETA subtype, suggesting the possible involvement of endogenous ET-1 in the mechanism of cardiac hypertrophy in vitro. In the present study, we studied the in vivo blockade effects of BQ123 on cardiac hypertrophy provoked by left ventricular overload with aortic banding in adult rats.

METHODS AND RESULTS

Forty rats were divided into four groups: (1) sham-operated rats without BQ123 administration, (2) rats with aortic banding without BQ123 administration, (3) sham-operated rats with BQ123 administration, and (4) rats with aortic banding with BQ123 administration. BQ123 (250 micrograms/h) was administered continuously by an osmotic pump starting 24 hours before operation. BQ123 blocked increases in the ratio of left ventricular weight to body weight and in the diameter of cardiomyocytes provoked by aortic banding at 1 week, but those blockade actions were no longer observed at 2 weeks. Skeletal alpha-actin and atrial natriuretic peptide (ANP) mRNA in the left ventricle, transcriptional markers for cardiac hypertrophy, significantly increased in the rats with aortic banding at 1 week and 2 weeks. In the rats with BQ123 administration, despite the hemodynamic overload, skeletal alpha-actin and ANP mRNA in the left ventricle remained at the control levels at 1 week; however, those blockade actions were abolished at 2 weeks. Plasma ET-1 levels increased after aortic banding, peaking at 24 hours, then returned to the basal level at 4 days. Prepro-ET-1 mRNA levels in the left ventricle also increased 24 hours after aortic banding, then declined to the basal level at 4 days.

CONCLUSIONS

These data suggest that endogenous ET-1 synthesized in the cardiovascular system plays a role in the mechanism of cardiac hypertrophy during the early phase of pressure overload in vivo.

In situ expression of interleukin-6 in psoriatic epidermis during treatment

Interleukin-6 (IL-6) is a multipotential cytokine which may act as a growth factor for keratinocytes. The epidermal hyperplasia of psoriasis may be explained in part by an overproduction of this cytokine. We have previously shown by in situ hybridization that IL-6 mRNA is most strongly expressed in the peripheral lesion of an advancing psoriatic plaque. In the present study, we investigated whether there were differences between the expression of IL-6 in untreated psoriatic epidermis and the lesion during the course of clinical improvement. In the untreated psoriatic lesion, the weak expression of IL-6 mRNA was localized in the lower epidermis. However, IL-6 mRNA was not detected in the clearly improved lesion. In the improving lesion, with clinically less scaling, less induration, and histologically thinner epidermis, IL-6 mRNA-expressing keratinocytes were detectable in a greater proportion of the total epidermal components than in the untreated, fully developed lesion. These results showed that IL-6 mRNA was strongly expressed in lesions with moderate epidermal hyperproliferation, indicating that this cytokine may play a role in the transitional phase during the course of improvement as well as in the lesion's formation.

The effect of fentanyl and morphine on neurons in the dorsal raphe nucleus in the rat: an in vitro study

The dorsal raphe (DR) nucleus is a system of nuclei lying in the midline of the lower brainstem constituting the largest collection of serotonin-containing neurons in the brain. The DR nucleus, which is under the influence of various synaptic inputs containing the excitatory amino acids (EAAs), serotonin and noradrenaline (NA), has been reported to be involved in the process of nociception. We studied the effects of fentanyl and morphine on the firing activity of neurons within the DR nucleus in the rat brain slice preparation in vitro using extracellular recording techniques. The decreased activity of DR neurons induced by these opioids was reversed upon application of naloxone. Since almost all neurons were silent, N-methyl-D-aspartate (NMDA) and noradrenaline were used to excite the DR neurons. Serotonin contained in the DR nucleus acts as a neuromodulator to enhance the excitatory effects of NMDA. All DR neurons were excited by NMDA, whereas 72% of the neurons were excited by NA. NA has a long-lasting effect on the firing activity of the neurons, although the firing pattern was less regular than that induced by NMDA. Of the total number of the DR neurons excited by NMDA and/or NA, 71% were inhibited by fentanyl and 73% by morphine. The results support our hypothesis that these opioids inhibit the firing activity of DR neurons and, in turn, might alter nociception directly and/or indirectly by modifying the central serotonergic system.

[A national surveillance study on alcoholic liver disease in Japan (1986-1991)]

National surveillance studies on alcoholic liver disease (ALD) in Japan were performed in 1978 and 1985, by a previous Japanese study group for ALD (Takeuchi group). In the present study, a subsequent nationwide surveillance study was performed from 1986 to 1991 and the results were compared with the previous two studies. In order to clarify the etiological relationships between hepatitis C virus (HCV) infection and ALD, an analysis was also done according to the new diagnostic criteria of ALD which was proposed by this group (Takada group). By the criteria of the Takeuchi group, the incidence of ALD was not significantly different during 1986 to 1991. However, the incidence of hepatocellular carcinoma (HCC) in alcoholic cirrhosis (AL-LC) clearly increased during this period. The analysis including the results of the previous study indicate that incidence of ALD reached a plateau in 1980 and then features of ALD in Japan entered a stable stage. However, HCC in AL-LC continued to show a linear increase from 1976 to 1991. Analysis with the new criteria of the Takada group was done in cases of 1990 and 1991. Approximately 2 out of 3 cases of ALD were caused by alcohol alone, and the remaining cases were caused by a combination of alcohol and HCV. Cases caused only by HCV were very rare. The main etiology in patients with alcoholic hepatitis and fibrosis was alcohol alone and that in chronic hepatitis of heavy drinkers was a combination of alcohol and HCV. In half of the patients with AL-LC, the etiology was alcohol alone and in the other half patients, it was a combination of both factors. In most patients with HCC, the etiology was a combination of alcohol and HCV, indicating that HCV infection may be important for the development of HCC in alcoholics.

The potential use of I-123 IMP scintigraphy for pelvic bone metastases in hepatocellular carcinoma. A comparison with Ga-67 scintigraphy

Conventional bone scintigraphy is often inconclusive in detecting bone metastases of hepatocellular carcinoma, suggesting the necessity of alternative scintigraphic agents. In this study, the diagnostic value of I-123 IMP scintigraphy was evaluated in 8 patients with 12 pelvic bone metastases from hepatocellular carcinoma, then compared with Ga-67 scintigraphy. Eleven of 12 lesions (91.7%) were detected by I-123 IMP scintigraphy; Ga-67 scintigraphy visualized 8 lesions (66.7%) in the same patient population. I-123 IMP scintigraphy is useful for detecting pelvic bone metastases of hepatocellular carcinoma with less physiologic accumulation in the intestine as compared with Ga-67 scintigraphy.

Clinical experience of 123I-IMP scintigraphy in detecting vertebral bone metastases of hepatocellular carcinoma. A comparison with bone scintigraphy with 99mTc-MDP

Although bone scintigraphy with 99mTc-MDP is a sensitive diagnostic method to detect bone metastasis, it is not specific for malignancy. A radioactive substance which accumulates specifically into metastatic lesions should be of value. 123I-IMP and bone scintigraphy with 99mTc-MDP were consecutively performed in patients with vertebral bone metastases from hepatocellular carcinoma and lumbar spondylosis deformans in a 7-day interval or shorter. The intensity of uptake was compared. Eighteen of the 20 metastatic lesions (90%) were classified as increased uptake areas in 123I-IMP scintigraphy. MDP-scintigraphy disclosed 16 metastatic lesions (80%), 9 as "hot" lesions (56%) and 7 as "cold" lesions (44%). 123I-IMP scintigraphy was negative in all 12 lesions of lumbar spondylosis deformans. Compared to MDP-scintigraphy, 123I-IMP scintigraphy was more sensitive in detecting vertebral bone metastases of hepatocellular carcinoma with smaller rates of false-positive and false-negative findings.

Induction of estrogen receptor and cell division in genital tracts of male mice by neonatal exposure to diethylstilbestrol

Estrogen receptor (ER) and ER mRNA expression and cell division induced by neonatal diethylstilbestrol (DES) exposure in male C57BL/Tw mouse genital organs were studied using immunohistochemistry, in situ hybridization, and cell counting at metaphase. A single injection of 3 micrograms DES on the day of birth induced ER in both epithelial (E) and stromal (S) cells of the epididymis and the seminal vesicles, in E cells of the ductus deferens, and in S cells of the ductus efferens and the anterior prostate 24 h after the injection. After 5 daily injections of DES, ER was induced in S cells of the ventral prostrate at 5 days of age. The staining intensity of ER increased in E cells of the epididymis and the ductus efferens at 5 days. A single injection of DES induced ER mRNA in both E and S cells of the ductus efferens, the caput epididymis, and the ductus deferens 4 to 12 h after injection of the newborn mice. A single injection of DES stimulated cell division of both E and S cells in the ductus deferens and the epididymis; cell division of S cells of the ductus efferens, the anterior prostate, and the urethra was stimulated 24 h after the injection. After 5 daily injections of DES, cell division was stimulated significantly in E and S cells of the epididymis, the ductus deferens, and the ventral prostate, and in S cells of the seminal vesicle at 5 days. At 30 days of age, mitotic rates were significantly higher in E cells of the seminal vesicles and the epididymides of mice given 5 daily injections of DES.(ABSTRACT TRUNCATED AT 250 WORDS)