Influence of development and aging on nicotinic receptor subtypes in rodent brain

The influence of development and aging on nicotinic receptor subtypes in rodent brain was investigated. 3H-nicotine and 3H-acetylcholine (3H-ACh) were used as receptor ligands. Specific binding sites for 3H-nicotine and 3H-ACh were detected in mouse brain during the late prenatal period. A drop in the number of 3H-nicotine and 3H-ACh binding sites was measured shortly after birth. The 3H-nicotine and 3H-ACh binding sites showed different time courses during prenatal development. Competition experiments using unlabelled (-)nicotine and 3H-nicotine revealed one population of high affinity nicotinic binding sites in the cortex of 1-day and 5-day-old mice whereas both a set of high and low affinity binding sites were found in adult mice. The proportion of cortical high and low affinity nicotinic binding sites did not change with aging although the absolute amount of high affinity nicotinic binding sites decreased. The 3H-nicotine binding showed different temperature dependence in rat brain of different ages. The results illustrate dynamic changes in nicotinic receptor properties during life span of rodents.

Distribution of juxtaglomerular cells and synthesis and release of renin granules in patients with renal artery stenosis

100 pieces of renal tissue from 4 patients with renal artery stenosis were studied histologically. Juxtaglomerular cells were found not only in the region close to the glomerulus but also in the proximal 2/3 of the afferent arteriole of the glomerulus, but not in the interlobular arterioles. In the cytoplasm of juxtaglomerular cells, three kinds of granules were found: crystalline granules (immature), the round or ovoid granules (mature), and the lobulated granules (fusion). Renin was synthesized in the rough endoplasmic reticulum and packaged in the Golgi complex. Electron microscopic findings suggested that the secretory microvesicles were produced on the surface of Golgi complex. They fused to form primary crystalline granules, which were enlarged by renin supplied by transportation vesicles and finally formed typical crystalline granules. The mature renin granules (round or ovoid) moved toward the periphery of the cytoplasma. Their limiting membranes on the side toward the basement membrane disintegrated and formed microvesicular bodies passing through the periplasm, and the basement membrane and were discharged into the interstitial matrix.

Relationship between clinical manifestations and coronary angiographic morphology in patients with coronary artery disease

To study the relationship between clinical manifestations and coronary anatomy and morphology, coronary angiography was performed in 20 patients with chronic stable angina (Group I), in 18 patients with unstable angina (Group II), and in 20 patients with previous myocardial infarction (Group III). Although the site and extent of coronary artery disease were similar among the three groups, coronary morphology differed considerably, with a concentric lesion occurring in 70% of Group I patients and an eccentric lesion in 62% and 63% of Group II and Group III patients, respectively. The study suggests that coronary lesion morphology may form an anatomic basis in determining clinical manifestations for patients with coronary artery disease. An eccentric coronary stenosis may be useful in identifying high-risk patients.

Ultrastructural findings in oral hyperpigmentation of HIV-infected patients

Oral hyperpigmentation has been observed in six HIV-infected patients, in two of whom systemic medication (ketokonazole, clofazimine) was supposed to be etiologically involved. Histologically, pigment was found in epithelial basal cells and particularly in subepithelial connective tissue. Ultrastructurally, the presence of premature melanosomes in subepithelial keratinocytes was of interest. Stimulation of melanocytes during HIV infection may occur in association with immunopathologic changes in the oral mucosa.

Impairment of baroreceptor reflex control of heart rate but not sympathetic efferent discharge by central neuroadministration of ethanol

We investigated the acute hemodynamic effects of ethanol microinjection into brain areas known to influence cardiovascular function and reflexes. In chloralose-anesthetized rats, ethanol had no effect on baseline mean arterial pressure, heart rate, or sympathetic efferent discharge when microinjected into the nucleus tractus solitarius, the dorsal motor nucleus of the vagus, the rostral ventrolateral medulla, or the posterior hypothalamus. On the other hand, ethanol microinjection into the anterior hypothalamus caused a site-dependent pressor effect and an increase in sympathetic efferent discharge. Baroreceptor heart rate response but not sympathetic efferent discharge response was impaired by ethanol microinjection into the nucleus tractus solitarius, the dorsal motor nucleus of the vagus, and the rostral ventrolateral medulla, suggesting that ethanol involves one or more of these areas in its inhibitory effect on baroreceptor heart rate response and that ethanol has a selective action on baroreceptor reflex control of heart rate. The findings that 1) the effect was dose dependent and 2) injection of ethanol outside of, or an equal volume of cerebrospinal fluid into, the nucleus tractus solitarius had no effect on the response strongly suggest that the observed effect on baroreceptor heart rate response was ethanol mediated. Ethanol microinjection into the dorsal motor nucleus of the vagus impaired the heart rate response, thus raising the possibility that leakage of ethanol to that area from the nucleus tractus solitarius might have contributed to its effect. These findings show that ethanol has a pressor and sympathoexcitatory site of action within the anterior hypothalamus and that it selectively impairs baroreceptor heart rate response via a central site of action; the mechanisms by which ethanol produces these effects remain to be elucidated.

DNA probe technique for diagnosis of human cytomegalovirus infection

A rapid diagnostic assay for human cytomegalovirus (HCMV) has been developed for detecting HCMV DNA in urine samples with 32P-labelled cloned fragment, Eco RI fragment B, of DNA from HCMV strain Towne. 3.2 pg of homologous fragment from HCMV DNA could be detected by the labelled probe, and it did not hybridize DNA from other herpes viruses or human cells in dot hybridization assay. The assay correctly identified all (100%) of 7 coded urine specimen cultures positive for HCMV and 9 (90%) of 10 urine sample cultures negative for HCMV. So the hybridization assay was correct and as sensitive as the currently available tissue culture technique. The infection levels of different populations, such as organ transplantation recipients, patients with infantile hepatitis syndrome, normal infants, fetuses, have been investigated by the hybridization assay in the present study.

Investigation of rat striatal dopamine D-1 receptors solubilized by digitonin with a precipitation method

[3H]SCH 23390 binding sites solubilized from rat striatal membranes by the detergent digitonin were investigated by using a polyethylene glycol precipitation method to separate the bound [3H]SCH 23390 from the free [3H]SCH 23390. The binding of [3H]SCH 23390 to the solubilized preparations was specific and saturable with a KD of 4.99 +/- 0.03 nM and a Bmax of 619 +/- 13 fmol/mg protein. The rank order of potency of dopamine agonists and antagonists for competing with [3H]SCH 23390 binding for the solubilized preparations was appropriate for dopamine D-1 receptors. The competition of SCH 23390 and S(-)-SCH 23388 with [3H]SCH 23390 binding for the solubilized preparations was stereoselective. However, the sensitivity of the dopamine agonist high-affinity binding to guanine nucleotide GTP was almost lost upon digitonin solubilization. Preincubating the membranes with dopamine preserved the guanine nucleotide sensitivity of agonist binding for membranes in solubilized preparations. These results proved that the polyethylene glycol precipitation method can be used for assay of digitonin-solubilized dopamine D-1 receptors in rat striatum.

Amplification and rearrangement of c-erb B proto-oncogenes in cancer of human female genital tract

There are two genes related to the v-erb B oncogene in the human genome. The c-erb B-1 gene encodes the epidermal growth factor receptor (EGF-r), and the c-erb B-2/neu gene encodes a receptor-like protein very similar to, but distinct from the EGF-r. Southern blot analysis of DNAs from 15 fresh human ovarian carcinomas showed that the c-erb B-2/neu gene was amplified in 3 tumors. The c-erb B-1/EGF-r gene was not amplified. However, in one case of adenocarcinoma of uterine endometrium, the c-erb B-1/EGF-r was found to be rearranged in the 5' region of this gene. The genomic structure of the rearranged c-erb B-1/EGF-r gene is similar to those found in the chicken v-erb B oncogene, which produces a truncated form of the EGF-r. The results suggest that amplification of the c-erb B-2/neu gene may play a role in the pathogenesis of ovarian carcinoma. Further, the human c-erb B-1/EGF-r gene in adenocarcinoma of uterine endometrium may be activated by a similar mechanism as that in the chicken v-erb B oncogene.

Identification and function of brain stem neurons regulating rat ileal water absorption

The central nervous system (CNS) regions regulating ileal water and ion absorption are unknown. We determined 1) the CNS origin of brain stem neurons that directly innervate the rat ileum, and 2) that these neurons influence intestinal water absorption. Horseradish peroxidase (HRP) was injected into the muscle layer of the rat ileum. The brains were examined for HRP reaction product (HRPRP) 3, 5, or 7 days later. Only cell bodies of the dorsal motor nucleus of the vagus (DMNV) were labeled. Unilateral cervical vagotomy prevented deposition in the ipsilateral DMNV. To determine whether the DMNV regulates ileal water absorption, electrical and chemical stimulation (30 microA, 4 Hz, 0.2 ms, and 300 pmol L-glutamate every 5 min, respectively) were used. Both the DMNV and the adjacent nucleus tractus solitarius (NTS) were stimulated, causing a reduction in water absorption. Bilateral vagotomy prevented the effect of bilateral electrical stimulation, but unilateral vagotomy did not prevent the decrease due to ipsilateral stimulation. These studies show that 1) the DMNV innervates the ileum, and 2) alteration of vagal efferent activity by stimulation of the DMNV and NTS reduces ileal water absorption.

[Plasma level of cyclic nucleotides in patients with congestive heart failure and their clinical significance]

Plasma concentrations of cyclic nucleotides were determined by radioimmunoassay in 196 cardiac patients. The results showed that plasma concentrations of cyclic AMP and cyclic GMP increased with the deterioration of cardiac function. Plasma cyclic GMP concentrations were correlated positively to the cardiothoracic ratios (CTR), PEP/LVET, and the intracardiac diameters measured by echocardiography respectively (r = 0.55 r = 0.50, and r = 0.55, P less than 0.001), and were correlated negatively to the left ventricular ejection fractions (LVEF) and LV short axis shortenings (LVSAS) (r = -0.53 and r = -0.50 respectively, P less than 0.001). There were only weak correlations between plasma cyclic AMP concentrations and CTR, PEP/LVET ratios, LVEF and LVSAS (r = 0.35, r = 0.38, r = 0.28, and r = -0.31, respectively, P less than 0.01). The correlations between plasma cyclic GMP concentrations and mean pulmonary artery pressures (r = 0.48, P less than 0.05) and mean left atrial pressures (r = 0.55, P less than 0.01) were also significant. In patients who had received cardioversion and valve replacement, plasma cyclic GMP concentrations decreased significantly. Thus the plasma concentrations of cyclic nucleotides could be used as a useful parameter in evaluation of cardiac function and therapeutic effect.

Selective blockade of dopamine D-1 receptor by SCH 23390 affects dopamine agonist binding to 3H-spiperone labeled D-2 receptors in rat striatum

This study investigated the effects of selective blockade of dopamine D-1 receptors by SCH 23390 and selective stimulation of the receptors by SKF 38393 on the binding characteristics of 3H-spiperone labeled D-2 receptors in rat striatum. Selective blockade of D-1 receptors by 50 nM SCH 23390 significantly decreased the affinity of dopamine agonist for 3H-spiperone labeled D-2 receptors, but did not influence dopamine antagonist binding to D-2 receptors. Selective stimulation of D-1 receptors by SKF 38393 (100 nM) did not affect either dopamine agonist or antagonist binding to D-2 receptors. The characteristics of the effect of SCH 23390 on dopamine agonist binding to D-2 receptors was similar to those of GTP, but different from those of sodium ion. This effect could not be due to a direct modification of D-2 receptors by SCH 23390. Pertussis toxin (IAP) treatment significantly decreased the affinity of dopamine agonist for D-2 receptors and reduced the abilities of both SCH 23390 and GTP to decrease the affinity of dopamine agonist for D-2 receptors. These results suggest, therefore, putative interregulatory mechanism between dopamine D-1 and D-2 receptors and the possible involvement of a pertussis toxin sensitive protein in this mechanism.

Value of angina pectoris after myocardial infarction in predicting extent of coronary artery disease

Clinical, hemodynamic, and angiographic data were examined in 53 patients who underwent catheterization within 6 months of documented acute transmural myocardial infarction (MI). The patients were divided into two groups on the basis of presence (23 patients, group I) or absence (30 patients, group II) of angina pectoris 1 month after MI. Group I patients had more severe coronary artery disease and a greater prevalence of multivessel disease than group II patients. Partial preservation of segmental left ventricular wall function in group I was related to the presence of collateral vessels. In patients with single vessel disease, incidence of spontaneous recanalization of the infarct-related artery was more common in group I as compared with those in group II. It is concluded that angina pectoris after MI suggests multivessel disease or infarct-related artery recanalization. Coronary angiography may be advised in these patients in order to select adequate therapeutic interventions and improve prognosis.

Effects of follicle-stimulating hormone and ovarian steroids during in vitro meiotic maturation on fertilization of rat oocytes

The present study examined the effects of gonadotropins and ovarian steroids during in vitro meiotic maturation of rat oocytes on their ability to undergo in vitro fertilization. Fully grown oocytes were isolated from antral follicles of immature rats and cultured as oocyte-cumulus cell complexes (OCC) under conditions in which completion of meiotic maturation occurs spontaneously. They were then exposed to spermatozoa under conditions in which oocytes matured in vivo exhibit high fertilization rates. Compared with oocytes from pregnant mare's serum gonadotropin (PMSG) or follicle-stimulating hormone (FSH)-treated rats, a similar proportion of the oocytes (greater than 80%) from untreated rats underwent germinal vesicle breakdown, but such oocytes had a lower rate of fertilization (70% vs. 20%). The presence of FSH during in vitro maturation restored the fertilization rate for oocytes from untreated rats, while a cytochrome P450 inhibitor, aminoglutethimide phosphate abolished this beneficial effect of FSH. The addition of progesterone during the in vitro maturation period duplicated the beneficial effect of FSH on fertilization rate of oocytes from untreated rats; oestradiol-17 beta was less effective in this regard, and 5 alpha-dihydrotestosterone was ineffective. These findings indicate that FSH and progesterone, although having no apparent effect on nuclear maturation of the oocyte, play an important role during oocyte maturation in enabling normal fertilization to occur.

[Experimental pancreatic duct occlusion with polyurethane]

Pancreatic transplantation requires an effective method to manage exocrine secretion. A new technique to eliminate the exocrine function of the pancreas by obstruction of the duct with polyurethane was investigated in terms of function, outcome and morphology. Polyurethane is an alcoholic solution of block copolymers with the property of polymerizing within 5-10 min. In this study the in-situ pancreatic tail model in dogs was utilized, the pancreatic duct was cannulated and injected with 2-3 ml of polyurethane. As a result, complete atrophy and fibrosclerosis of the exocrine tissue was obtained leaving islets well vascularized and functioning for the entire experimental periods. All animals remained normoglycemic and showed normal K-values. Amylase levels were found to be maximally elevated at 24 h and returned to normal within 2 weeks after duct occlusion. Insulin, glucagon and somatostatin levels remained normal. Because of its ability to effect a complete occlusion of the pancreatic ducts with subsequent atrophy of the exocrine gland and without notable disturbance of endocrine function, we feel that polyurethane solution is superior to previously used materials for this purpose.

Changes of glycoconjugates in human hepatocellular carcinoma

Receptors of 12 lectins in 25 cases of human hepatocellular carcinomas (HCC) were histochemically investigated by avidin-biotin-peroxidase complex (ABC) method. Liver tissues of five cirrhotic patients and five normal subjects were used as controls. SJA receptor was absent both in HCC and controls, while LCA and PSA receptors were present in all tissues studied here. Receptors of DBA, PHA, PNA, UEAI and SBA which did not bind to normal, cirrhotic and pericarcinomatous liver tissues had the positive rates of 4%, 44%, 16%, 4% and 12% in HCC, respectively. Four lectins which strongly bound to the non-cancer liver tissues had their receptors in 96% (ConA, WGA, RCAI) and 36% (BSAI) of HCC. The pretreatment of tissue sections with neuraminidase abolished most of WGA receptors and exposed some PNA binding sites. There were many differences in lectin distribution between HCC and noncancer liver tissues. The changes of glycoconjugates in HCC were discussed.

Oral hyperpigmentation in HIV-infected patients

Six cases of oral hyperpigmentation in HIV-infected patients are reported. While in two patients the lesions could be related to systemic clofazimine or ketoconazole therapy, in the other patients the cause remained unknown. Clinically, the pigmentations were characterized by a sudden onset and the appearance of well-defined, brown-black macules in the buccal mucosa, the gingiva, the hard palate, or the lateral borders of the tongue. In one patient, longitudinal hyperpigmented striae were observed on all fingernails and toenails. Histologically, hyperpigmentations associated with systemic medication revealed accumulation of melanin in phagocytes and extracellularly within the connective tissue. In those lesions with unknown cause, melanin was restricted to keratinocytes of the basal cell layer or to extracellular foci in the lamina propria. The clinical and histologic findings, as well as differential diagnosis, are discussed.