Effect of a sulfonium analog of dopamine on the depolarization-induced release of [3H]acetylcholine from mouse striatal slices

P3 have synthesized a chemical analog or dopamine in which the amino group has been replaced by a charged dimethylsulfonium group. The dopaminergic activity of this drug was evaluated by determining its ability to inhibit the depolarization-evoked release of [3H]acetylcholine from mouse striatal slices. The slices were preincubated with [3H]choline (0.1 microM) and then superfused in physiological medium. [3H]Acetylcholine release was induced by exposure of the slices to a high potassium medium (12.5 mM) for 5 min. The sulfonium analog of dopamine, dopamine, and apomorphine inhibited the evoked [3H]acetylcholine release with IC50 values of approximately 10, 2.0, and 0.3 microM respectively. The inhibition by the sulfonium analog was reversed by fluphenazine (1 microM), suggesting that the inhibition of [3H]acetylcholine release was due to the activation of dopaminergic receptors. The sulfonium analog also inhibited the uptake of [3H]dopamine into striatal slices and caused the release of exogenously taken up [3H]dopamine from these slices. The release of [3H]dopamine by the sulfonium analog was inhibited by cocaine (3 microM), suggesting that the drug-induced release of [3H]dopamine was dependent on the carrier-mediated uptake of the sulfonium analog into dopaminergic neurons. The inhibition of the evoked [3H]acetylcholine release by high concentrations (30 and 60 microM) of the sulfonium analog did not appear to be mediated by endogenous dopamine release, since the analog still inhibited [3H]acetylcholine release from slices after reserpine-alpha-methyl-p-tyrosine treatment. However, the inhibitory effect of the sulfonium analog at 10 microM was reduced by reserpine-alpha-methyl-p-tyrosine treatment, suggesting that the inhibition at lower concentrations was mediated through endogenous DA release. These results suggest that a charged compound can act as a substrate for the dopamine carrier and can activate the dopamine receptor regulating acetylcholine release. They also indicate that the nitrogen on the dopamine molecule is not essential for dopamine agonist activity.

Differential effects of mecamylamine on the nicotine induced changes in amine levels and turnover in hypothalamic dopamine and noradrenaline nerve terminal systems and in the secretion of adenohypophyseal hormones in the castrated female rat. Evidence for involvement of cholinergic nicotine-like receptors

The effects of mecamylamine on the nicotine induced changes in hypothalamic catecholamine (CA) levels and turnover in female rats ovariectomized for one month have been evaluated using a quantitative microfluorimetric approach to measure CA levels in sections of brains treated according to the Falck-Hillarp procedure for the cellular demonstration of CA. In the same group of animals the serum prolactin, LH, FSH, TSH, GH and corticosterone levels were measured using radioimmunoassay procedures. The nicotine treatment induced a significant depletion of amine stores and an increase of amine turnover in dopamine (DA) and noradrenaline (NA) nerve terminals of the median eminence and of the peri- and paraventricular and dorsomedial NA systems of the hypothalamus using the tyrosine hydroxylase (TH) inhibition model. Mecamylamine (2 X 1 mg/kg) partly counteracted the nicotine induced reduction of amine stores in peri- (anterior part) and paraventricular NA nerve terminal systems as well as the nicotine induced increase of NA turnover in these systems, but not the action of nicotine on the CA systems of the median eminence. Nicotine (4 X 2 mg/kg) significantly and markedly reduced prolactin, LH, TSH, and GH secretion increased corticosterone secretin but did not influence FSH secretion. These effects were partly counteracted by mecamylamine (2 X 1 mg/kg) in the case of prolactin, LH and TSH secretion but not in the case of GH and corticosterone secretion. Taken together the results show that mecamylamine treatment (2 X 1 mg/kg) differentially counteract nicotine induced changes of amine levels and turnover in peri- (anterior part) and paraventricular NA nerve terminal systems indicating that the cholinergic nicotine-like receptors located in peri- (anterior part) and paraventricular areas may be more susceptible to the blocking activity of mecamylamine than those located in the median eminence area. Furthermore, the inhibitory effects of nicotine on prolactin, LH and TSH secretion are differentially counteracted by mecamylamine. In conclusion, other inhibitory systems than the tuberoinfundibular DA neurons in the MPZ and LPZ must also be involved in mediating the inhibitory effects of nicotine on prolactin, LH and TSH secretion and different types of cholinergic nicotine-like receptors may exist.

Radioprotection of normal tissues against gamma rays and cyclotron neutrons with WR-2721: LD50 studies and 35S-WR-2721 biodistribution

The ability of WR-2721 to protect mice against two modes of death following whole-body radiation with 137Cs gamma rays or d(22)+Be neutrons was examined. For single fractions, 400 mg/kg WR-2721 was administered prior to irradiation. In two-fraction exposures, the dose was 275 mg/kg given prior to each fraction. Dose modification factors (DMFs) were calculated as ratios of LD50 values. For single fractions of gamma rays, the DMF was 1.74 for the LD50/7 end point and for LD50/30, the DMF for single fractions was 2.25. For two fractions 3 hr apart, it was 1.88. For single fractions of cyclotron neutrons, the DMF was 1.32 for LD50/7. Measured with the LD50/30 end point, the DMF for single neutron doses was 1.41 and for two fractions, 1.19. Substantial radioprotection of bone marrow and intestinal epithelium against cyclotron neutrons was seen in these investigations. Biodistribution studies were done following ip injection of 35S-labeled WR-2721 into C3H mice bearing RIF-1 tumors. Blood levels peaked at 10 min after injection and declined thereafter. Most normal tissues achieved maximum levels of 35S at 30 to 60 min postinjection and high concentrations were retained in most tissues for up to 2 hr. Assuming that all 35S is in parent compound or dephosphorylated radioprotective metabolites, the concentration of protector (milligram per gram tissue) in various organs at 30 min postinjection ranked as follows: kidney greater than submandibular gland much greater than liver = lung greater than gut greater than heart much greater than blood greater than skin greater than tumor greater than brain. High levels of 35S were achieved and retention times were long in certain normal tissues which respond at early or late times postradiation and may be dose limiting in radiotherapy: kidney, liver, salivary gland, and lung. These combined observations suggest that there is potential for protecting dose-limiting, late-responding normal tissue in the radiotherapy of human cancer with both neutrons and conventional radiotherapy.

Metastatic carcinoma with an unknown primary

The patient is a 54-year-old white female who was well until 3 weeks prior to admission when she noted vague right upper quadrant pain exacerbated by meals. She lost 12 lbs over that period of time. She complained as well of posterior scalp, left hip, and back pain on initial presentation. Physical examination at the time of admission to hospital showed a middle-aged female in no acute distress. Her vital signs were normal. There was a 1.5 X 1.5-cm firm, tender nodule over the occiput. There was no peripheral adenopathy. The breasts, lungs, and heart were normal. The liver was 14 cm in span. The remainder of the physical examination including a pelvic examination was unremarkable. On admission, the only abnormal laboratory studies were SGOT 106, SGPT 139, and alkaline phosphatase 190. Her chest X ray, flat plate of the abdomen, and mammograms were all normal.

Molecular geometry and crystal structure of 9-acetylanthracene

The molecular geometry of 9-acetylanthracene has been established by X-ray diffraction analysis. The acetyl group is twisted out of the plane of the aromatic π-system by 88�. The intermolecular geometry in crystalline 9-acetylanthracene is characterized by head-to-tail pairs with an interplanar distance of 3.42 � between parallel aligned anthracene moieties. Parallel adjacent molecules of 9-acetylanthracene deviate from perfect overlap by a long-axis shift of 1.35 �, and a short-axis shift of 0.88 �.

Biological and macromolecular properties of murine cells persistently infected with MHV-JHM

A persistently-infected neuroblastoma culture [Neuro-2A( JHMV )] was established with the murine hepatitis virus JHM [MHV-JHM]. After 100 days of passage, the endogenous virus [Neuro-2A( JHMV ) end] released by this culture was unable to induce the syncytia typical of MHV-JHM and the endogenous virus was not temperature-sensitive. The Neuro-2A( JHMV ) culture was cured of virus production by passage under neutralizing antibody [Neuro-2A( JHMV )Ab]. The Neuro-2A( JHMV ) and the Neuro-2A ( JHMV ) Ab cultures were as susceptible to heterologous infection with mengovirus and vesicular stomatitis virus as the uninfected Neuro-2A culture. However, the Neuro-2A ( JHMV ) and Neuro-2A( JHMV ) Ab cultures were partially resistant to homologous superinfection by MHV-JHM and the closely related MHV-A59. Virus related to MHV-JHM was rescued from the antibody-cured cells by cell fusion. The synthesis of MHV-JHM specific antigens by Neuro-2A( JHMV ) cells, Neuro-2A( JHMV ) Ab cells and 17 Cl-1 cells infected by Neuro-2A( JHMV ) end was studied by SDS-PAGE. The genomic RNAs of MHV-JHM and Neuro-2A( JHMV ) end were compared by oligonucleotide mapping. The results of the protein and RNA studies indicated that the genome of Neuro-2A( JHMV ) end was substantially modified from the genome of MHV-JHM, but the modifications did not significantly alter the molecular size of the viral-specific proteins.

Protein synthesis in cells infected by murine hepatitis viruses JHM and A59: tryptic peptide analysis

The structural and intracellular proteins of the murine hepatitis viruses MHV-JHM and MHV-A59 were studied by tryptic peptide mapping. The results demonstrated that the virions contained three distinct proteins: the two related chains of the E2 complex, the nucleocapsid protein and the heterogeneous E1 complex. Five distinct virus-specific proteins were synthesized by infected cells. Three of the five intracellular proteins contained tryptic-peptides with properties similar to the three structural proteins. Models describing the evolution of the proteins are proposed. Although the pathogenic properties of MHV-JHM and MHV-A59 differ greatly, the tryptic peptide maps of the corresponding proteins of these MHV strains were remarkably similar.

Effects of obesity on estradiol metabolism: decreased formation of nonuterotropic metabolites

Obesity is associated with an increased incidence of reproductive dysfunction and estrogen-linked diseases. In the present study, we have examined the principal oxidative biotransformations of estradiol in 13 obese premenopausal females and 10 obese males compared to those in 9 premenopausal female and 15 male controls. These studies were carried out using a recently devised, sensitive radiometric method which permits the assessment of the total in vivo oxidative metabolism of estradiol at specific sites (i.e. 17 alpha, 16 alpha, or C-2) on the steroid molecule. Our results indicate that obesity (greater than 60% above ideal body weight) is associated with significant decreases in hydroxylation at C-2 in both sexes (P less than 0.001 for females and P less than 0.02 for males) and in oxidation at 17 alpha in premenopausal females (P less than 0.05) compared to that in age-matched, normal weight controls. Analysis of the plasma 3H2O specific activity curves suggested a slight decrease in the rate of 17-oxidation in obese subjects. The extent of hydroxylation at 16 alpha was not significantly affected by obesity. These metabolic alterations documented in obesity could result in a relative hyperestrogenic state, since, unlike the other estrogen metabolites, the 2-hydroxyestrogen compounds display relatively little peripheral estrogenic activity. This metabolic alteration on a prolonged basis might be contributory to the prevalence of certain hormonally related diseases in obese individuals.

Quality assurance in radiographic imaging included in the film marking procedure

Quality assurance for the radiographic processing can only be obtained by the aid of a continuous densitometric control. A method is described which uses a densitometric step wedge included in the marker equipment. It gives a constant radiation dose to the marking area. The step wedge is exposed simultaneously with the film marking. Disturbances in the radiographic procedure can thus immediately be detected.

Early precursors of pancreatic cancer in college men

From college data on 50,000 male former students, the records of 126 men who died of pancreatic cancer in a 16-50 yr follow-up period were compared with those of 504 surviving classmates with respect to physical and social characteristics. Return mail questionnaires received from 30,000 surviving alumni in 1962 or 1966 also were reviewed for characteristics that might predict altered risk of pancreatic cancer. Strong positive associations were found for cigarette smoking as reported both during college (p less than 0.001) and at time of questionnaire return (p = 0.03). Smoking 10 or more cigarettes per day during college corresponded to a relative risk of 2.6 with 95% confidence limits 1.5 to 4.6, and a positive smoking history at questionnaire return yielded a relative risk of 2.4 (1.1-5.1). No association was found for collegiate coffee drinking, either before or after adjustment for cigarette smoking. The relative risk for coffee drinking adjusted for smoking was 1.1 (0.7-1.8). In contrast, collegiate tea consumption was associated with a reduction in pancreatic cancer risk. The relative risk for tea drinking adjusted for smoking was 0.5 (0.3-0.9). Men who at college physical examination complained of occasional abdominal pain or discomfort had increased relative risk of pancreatic cancer (3.1 : 1.1-9.0) in the follow-up period.

Regression analysis of cytopathological data

Epithelial cells from the human body are frequently labelled according to one of several ordered levels of abnormality, ranging from normal to malignant. The label of the most abnormal cell in a specimen determines the score for the specimen. This paper presents a model for the regression of specimen scores against continuous and discrete variables, as in host exposure to carcinogens. Application to data and tests for adequacy of model fit are illustrated using sputum specimens obtained from a cohort of former asbestos workers.

Lack of type C virus antibodies in systemic lupus erythematosus

Twelve systemic lupus erythematosus (SLE) and 10 normal sera were similarly reactive in an assay for cytotoxic antibody to type C virus-infected and uninfected cells, but both were less cytotoxic for infected cells. Thus antibodies to type C viruses were not detected in SLE or normal sera, but type C infection may interfere with antibody recognition of other cell membrane antigens.

Heterotopic brain tissue simulating a neonatal tonsil

Heterotopic brain is a developmental anomaly in which isolated brain tissue is found outside the cranial cavity. A case of this rare anomaly, simulating a neonatal palatine tonsil, is presented.

Synthesis and pharmacological evaluation of sulfonium analogues of dopamine: nonclassical dopamine agonists

In order to test whether the nitrogen/ammonium moiety in the dopamine molecule is required for dopaminergic activity, we have synthesized two sulfonium analogues of dopamine and tested them for biological activity in an in vivo and in an in vitro system. These analogues have provided a means of investigating (1) the ability of the sulfonium function to serve as a bioisostere for the dopamine amino group and (2) whether charged molecules have the ability to bind to dopamine receptors. Both sulfonium analogues, 1 and 2, as well as dopamine, when injected directly into the striatum of rats, previously lesioned unilaterally with 6-hydroxydopamine (6-OHDA), produced circling behavior. The potency of the sulfonium analogues was approximately one-tenth that of dopamine. The effects of all three compounds on circling were inhibited by the dopamine antagonist haloperidol. In addition, both sulfonium analogues inhibited the high affinity binding of radiolabeled dopamine to a crude membrane fraction prepared from the striatum. This study suggests that the nitrogen atom found in th dopamine molecule is not essential for dopaminergic activity, since the nitrogen can be replaced by a sulfonium functional group for this activity.

Treatment of stage D prostatic carcinoma with megestrol acetate

Nine previously untreated patients with stage D prostatic carcinoma received megestrol acetate 40 mg orally three times daily. Responses included five partial regressions, two stabilizations, and two progressions. Duration of response ranged from 3+ to 33+ months, with a mean of 11.7 months and a median of 12 months. Three of five patients who had failed prior hormonal therapy remained objectively stable while receiving megestrol acetate. No gastrointestinal toxicity, gynecomastia, fluid retention, or thromboembolic complications were observed during treatment. Weight gain of 5 to 51 pounds occurred in seven of 14 patients.

Fast stopped-flow microcalorimeter

A fast stopped-flow microcalorimeter using a thermistor and an a.c. bridge is described. Time resolution, limited by the response of the thermistor, is 3 ms for t 1/2 while sensitivity is 100 mu degree C in this bandpass. A reaction requires 0.3 ml of each reactant. The microcalorimeter is adiabatic to within 2% for 2 s and mixing may be repeated every 5 min. Computer finite element simulation techniques (FEST) are used to correct for the thermistor response time and heat losses. Results of tests with reactions of NaOH and HCl, NaHCO3, and HCl, and glyclyglycine and CO2 agree with published kinetic and thermodynamic values to within an experimental error of less than 2%.