Synthesis and evaluation of optically pure [3H]-(+)-pentazocine, a highly potent and selective radioligand for sigma receptors

Tritium-labeled (+)-pentazocine ([3H]-1b) of specific activity 26.6 Ci/mmol was synthesized in 3 steps starting with (+)-normetazocine (2) of defined optical purity. [3H]-1b has been characterized as a highly selective ligand for labeling of sigma receptors. Competition data revealed that [3H]-1b could be displaced from guinea pig brain membrane preparations with a number of commonly used sigma receptor ligands. [3H]-1b exhibited saturable, enantioselective binding with a Kd of 5.13 +/- 0.97 nM and a Bmax of 1146 +/- 122 fmol/mg protein. Phencyclidine (PCP) displaced [3H]-1b with low affinity while MK-801 was inactive, thus indicating insignificant activity at the PCP-binding site; apomorphine failed to displace [3H]-1b indicating lack of dopamine receptor cross-reactivity. Since the affinity of [3H]-1b is about 6 times that of the two commonly employed sigma ligands ((+)-3-[3H]PPP and [3H]DTG) and since it is more selective for sigma receptors than the benzomorphan [3H]SKF-10,047, it represents the first example of a highly selective benzomorphan based sigma receptor ligand. [3H]-1b should prove useful for further study of the structure and function of sigma receptors.

The histochemical location of three diagnostic enzymes in the marmoset liver

The histochemical locations of alkaline phosphate (ALP), leucine aminopeptidase (LAP) and gamma glutamyltransferase (GGT) were demonstrated in the liver of the marmoset (Callithrix jacchus). Although all three enzymes were located in cell membranes, the location of LAP was demonstrated by a chromogenic substrate, in the canalicular membrane. GGT was seen in a vascular network, provisionally identified as the peribiliary arterial plexus. Possible diagnostic applications in toxicology are discussed.

High efficiency transformation ofBrassica napus usingAgrobacterium vectors

An efficient procedure for obtaining transgenicBrassica napus plants usingAgrobacterium binary vectors is described. The target tissue for the transformation is the cut end of cotyledonary petioles. These tissues, when cultured with their lamina intact, show a regeneration frequency of more than 80%. The cells of this cut surface, which undergo organogenesis, are very susceptible to topical infection byAgrobacterium. The cocultivation method used does not require feeder layers or use of exogenously applied promoters of virulence. After 72h of infection withAgrobacterium the explants were transferred to selective regeneration medium. Using kanamycin (15μg cm(-3)) for selection, transgenic plantlets emerged within 3 weeks. These plantlets which appeared on over half the explants were excised and rooted for a further 7-10 days. When the plants were large enough, leaves were taken for assay of NPT II activity using dot blots. Most of the plants surviving the selection showed substantial NPT II activity. The frequency of transformation and yield of transgenic plants was higher than in previously reported methods with this species. Southern blotting revealed that integration of the T-DNA frequently occurred in multiple copies and at multiple loci in the genome. The transgenicB. napus plants all grew normally and developed fertile flowers. The transgenic plants were self-pollinated and their progeny studied by two methods. The first was a single-embryo NPT II assay performed on developing seeds of these selfed-plants. The second was a leaf bleaching assay performed by selection of germinating seedlings of the selfed progeny. Both assays yielded segregation ratios consistent with the number of integration events indicated by Southern blots. The method should have broad application in studies of gene expression in theBrassicaceae and will be a cost-effective alternative to those seeking to improveBrassica crops by introduction of foreign genes.

The nursing management of pain in the community: a theoretical framework

This paper is based upon a research project designed to investigate the nursing management of pain in the community. A theoretical framework is described which has been designed to encompass the complexities of different types of pain, individual differences in reaction to pain, and to identify key differences between patients who cope with pain and those who do not. The framework is based on a model of stress, the concept of controllability, and contemporary learning theory. It identifies a unique role for the nurse in pain management and will be used to direct a study into strategies which nurses can use to enhance the coping abilities and resources of elderly patients in the community with pain.

The diagnostic usefulness of isocitrate dehydrogenase (ICDH) in the marmoset (Callithrix jacchus)

Marmosets were given either a hepatotoxin, carbon tetrachloride, orally or an i.m. injection of a mytoxin, chlorpromazine. Although muscle damage alone caused small increases in the plasma levels of lactate dehydrogenase, alanine aminotransferase, aspartate aminotransferase and isocitrate dehydrogenase (ICDH), only the isoenzyme analysis of ICDH can differentiate definitely between liver and muscle damage. Only very severe muscle damage can increase the plasma concentration of this enzyme but, in this case, the elevation of plasma creatinine kinase levels helps differentiation. It is recommended that the elevation of ICDH is the most specific indicator of hepatic damage in the marmoset.

Activation of protein kinase C by short chain phospholipid micelles

PKC (80 kDa) can be cleaved by limited proteolysis into distinct catalytic (50 kDa) and regulatory (32-35 kDa) fragments. After cleavage, the catalytic fragment is active in the absence of Ca2+, phospholipid, or DAG while the regulatory fragment is found associated with phospholipid and continues to bind phorbol esters in a Ca2(+)- and PS-dependent manner (28, 29). In the holoenzyme, the association of the regulatory domain with the membrane may be important to release the catalytic domain from inhibition by the regulatory domain. We have presented evidence indicating that effective membrane binding occurs through interaction with the hydrophobic and/or interfacial regions of the bilayer, and does not result from binding to individual phospholipids. In vivo and in vitro studies suggest that the binding event is carefully regulated. An important function of Ca2+ may be to modify the local structure of the membrane, and thus affect the ability of PKC to associate with it. For at least one of the isozymes, however, Ca2+ may also play an additional role at a site distant from the membrane, suggesting the possibility that the isozymes may be differentially regulated.

Congenital diverticulum of the left ventricle presenting as heart failure and diagnosed by magnetic resonance imaging

We report a 25-year-old man with a probable congenital diverticulum of the heart. The diverticulum was clearly shown using magnetic resonance imaging.

Motor effects of two sigma ligands mediated by nigrostriatal dopamine neurons

(+)-Pentazocine, a potent sigma ligand that lacks affinity for PCP receptors, produced dose-dependent contralateral circling behavior following microinjections in the substantia nigra of rats. This effect was attenuated by 6-hydroxydopamine (6-OHDA) lesions of ascending dopamine neurons and enhanced by systemic injections of amphetamine, 6-OHDA lesions also attenuated the circling produced by another selective sigma ligand, 1,3-di-o-tolylguanidine (DTG). These findings suggest that sigma receptors are involved in the neural control of movement and the regulation of the ascending dopamine system. Since all typical antipsychotic drugs tested bind to sigma receptors with Ki values less than 1 microM, these findings further suggest that sigma receptors may mediate some of the motor side effects of antipsychotic drug therapy.

Pelvic exercise and gait in hemiplegia

The purpose of this study was to describe and compare the gait of 20 patients with hemiplegia secondary to cerebrovascular accident (CVA) before and after a treatment regimen of resisted pelvic motions. Ten women and 10 men were studied, with a mean age of 48 years and a mean duration post-CVA of two months. Nine subjects (45%) were right hemiplegic, and 11 subjects (55%) were left hemiplegic. Treatment consisted of four sets of five repetitions each of manually resisted pelvic anterior-elevation and posterior-depression movements on the involved side. An insole footswitch system, knee electrogoniometer, and force walking aid were used in gait analysis performed before treatment, immediately after treatment (posttest 1), and 30 minutes after treatment (posttest 2). Results showed significant overall improvement in gait in posttest 1 (p less than .005) compared with the pretest. This improvement, however, was not maintained in posttest 2. Ten patients improved overall in posttest 1; only 4 patients also showed improvement in posttest 2. The major improvements seen immediately after treatment were observed in stance stability and limb advancement in the involved limb. More research is needed to identify an optimum treatment with carry-over using this technique.

Inhibition of rubral neurons by a specific ligand for sigma receptors

1,3-Di-ortho-tolylguanidine (DTG), a compound with marked selectivity for sigma receptors was iontophoretically applied to neurons in the red nucleus and nearby mesencephalic reticular formation. Spontaneous firing of rubral neurons was reduced by DTG in most cases. However, in the reticular formation, less than half of the cells tested showed inhibition; the remaining cells showed either an increase in rate or no consistent response to DTG. This corresponds to the greater density of sigma receptors in the red nucleus and supports previous work which suggests that sigma receptors play a role in the regulation of movement and posture.

Distribution of opiate receptors within visual structures of the cat brain

The distributions of mu, delta, and kappa opiate receptors within visual regions in the cat cortex, thalamus and midbrain were determined by in vitro autoradiography. The overall distribution of receptors was examined using [3H]-etorphine, a ligand that nonselectively labels all types of opiate receptors. [3H]-[D-Ala2, N-Me-Phe4,Gly(ol)5]-enkephalin (DAGO) was used to selectively label mu receptors, [3H]-[D-Pen2, 5]-enkephalin (DPDPE) for delta receptors, and [3H]-bremazocine for kappa receptors. Each of the areas examined showed clear opiate receptor binding with [3H]-etorphine and a differential distribution of mu, delta, and kappa receptors. Compared to other cortical regions, opiate binding in layers 3 and 4 of areas 17 and 18 was sparse. In the adjacent areas a more uniform distribution across layers was observed. The density of kappa opiate receptors was greater in cortex than in subcortical structures, whereas the reverse was the case for mu receptors. Nevertheless, all three types of opiate receptors were found in the ventral and dorsal subdivisions of the lateral geniculate (LGN), the pulvinar complex, and the suprageniculate nucleus. In the midbrain, the superficial layers of the superior colliculus were heavily labelled with the mu receptor ligand, and modestly with the kappa ligand. Compared with other midbrain and diencephalic areas, delta binding was low in the superior colliculus. These results suggest that the diverse effects of opiates on visual perception are mediated by the unique distributions of opiate receptor types throughout the visual areas in the brain.

Purification and characterization of pentagalloylglucose, and alpha-glucosidase inhibitor/antibiotic from the freshwater green alga Spirogyra varians

An alpha-glucosidase inhibitor/antibiotic was purified from the freshwater green alga Spirogyra varians and was determined to be the pentagalloylglucose 3-O-digalloyl-1,2,6-trigalloylglucose.

Epidermal growth factor (urogastrone) in human seminal plasma from fertile and infertile males

Epidermal growth factor/urogastrone (EGF/URO) was measured in the seminal plasma of 214 untreated patients attending an infertility clinic. Patients were assigned groups according to sperm density and progressive motility and in the case of azoospermia into an obstructive etiology or germinal failure. There was no significant variation in mean EGF/URO levels between groups, suggesting that this peptide plays no role in the density or motility of sperm associated with fertility. Other functions this peptide may fulfill in the female reproductive tract, including that of immunosuppression, are discussed.

Hypersensitivity vasculitis complicating intravenous streptokinase therapy in acute myocardial infarction

A 52-year-old man developed a hypersensitivity vasculitic rash on his legs nine days after receiving intravenous streptokinase therapy for acute myocardial infarction. The histological and immunological features and the differential diagnosis of this unusual complication of streptokinase therapy are reviewed.

Selective screening for abdominal aortic aneurysms with physical examination and ultrasound

Abdominal aortic aneurysm (AAA) is an important cause of preventable death in older persons. Persistently high rupture mortality rates indicate that these deaths can be prevented only by early detection and treatment of AAA. In an effort to develop an effective and efficient program of AAA detection, we selectively screened a high-risk population. Men aged 60 to 75 years with hypertension and/or coronary artery disease were randomly selected from a general medicine clinic and screened with physical examination and ultrasound. Eighteen previously unsuspected aneurysms, 3.6 to 5.9 cm in size (mean, 4.4 cm), were detected in 201 patients, for a prevalence of 9% (95% confidence interval: 4.7% to 13.3%). The specificity and positive predictive value of ultrasound were each 100%. Abdominal palpation detected only half of these aneurysms, but missed none in patients with an abdominal girth less than 100 cm (n = 6). This degree of sensitivity did not occur with "routine" examinations and requires that the examination be directed specifically toward AAA detection. We conclude that undiagnosed AAAs are common in this large subgroup of the clinic population, that ultrasound is an excellent screening test for AAAs, and that physical examination may be adequate for screening thin patients. We recommend that every two or three years persons over the age of 50 years undergo careful abdominal palpation aimed at detecting AAAs, as part of the periodic health examination. We further recommend that obese older men at high risk for AAA have at least one-time screening with abdominal ultrasound, regardless of findings on physical examination.

Tissue activities of enzymes of diagnostic interest in the marmoset and rat

The activities of enzymes of diagnostic interest were investigated in the liver, heart, kidney and muscle of the marmoset (Callithrix jacchus) and the rat. Methods of tissue extraction which gave maximal enzyme activity were used and comparison between the species showed some major differences. AST, LDH and GDH showed a similar distribution in both species but ICDH activity was much higher in the rat heart than in any other rat or marmoset organ. ALP, LAP and GGT were present in much higher activities in the rat kidney than in the marmoset kidney, a finding which was reversed in the liver of these animals. The major ALT-containing organ in the rat was the liver but, in the marmoset, this enzyme was found in relatively large quantities in the heart and muscle also. These differences can be of importance when plasma enzyme activities are measured following tissue damage.

Rotational behavior mediated by dopaminergic and nondopaminergic mechanisms after intranigral microinjection of specific mu, delta and kappa opioid agonists

The regulation of motor behavior by mu, delta and kappa opiate receptors in the substantia nigra was examined. Unilateral microinjections of specific mu (DAGO), delta (DPDPE) and kappa (U-50,488H) ligands into the substantia nigra pars reticulata of rats produced dose-dependent contralateral turning. The opiate antagonist naloxone blocked these effects, suggesting that the circling was mediated through opiate receptors. The involvement of midbrain dopaminergic systems in this behavior was tested in two ways. Unilateral 6-hydroxydopamine lesions of the medial forebrain bundle decreased the circling produced by DPDPE and DAGO but increased the circling produced by U-50,488H. In contrast, activating dopaminergic systems with systemic injections of amphetamine increased the circling produced by DAGO and DPDPE but had no effect on the circling produced by U-50,488H. These findings suggest that kappa opioids exert opposite effects on locomotion: motor activation through the SNR and motor inhibition through actions in the SNC. Furthermore, the data suggest that the actions of kappa opioids in the SNC are opposite to those produced by mu and delta opioids.

Evidence for a role of haloperidol-sensitive sigma-'opiate' receptors in the motor effects of antipsychotic drugs

Haloperidol exhibits a high affinity for a subclass of sigma- "opiate" binding sites which have a unique anatomic distribution and a unique drug selectivity pattern. These binding sites differ from phencyclidine-sensitive sigma-receptors and are found in many brain areas involved in the control of movement. 1,3-Di-o-tolylguanidine (DTG), a highly selective ligand for the haloperidol-sensitive sigma-receptor, produced marked dystonia in rats after microinjection into the red nucleus, a motor area rich in this receptor. Haloperidol and another sigma-ligand [(+)-SKF 10,047] produced similar effects. On the other hand, clozapine, an antipsychotic drug which fails to bind to sigma-receptors and fails to induce movement disorders in humans, failed to induce these dystonic reactions in rats. Phencyclidine was also without effect, as were injections of the active compounds in sites distant to the red nucleus. Microinjections of DTG in the substantia nigra produced vigorous contralateral circling behavior at extremely low doses. These findings suggest that sigma-binding sites represent biologically functional receptors that are active in the neural control of movement. Since haloperidol (and many other antipsychotic drugs) exhibit an affinity for sigma-receptors which is at least equal to its affinity for dopamine receptors, these data raise the further possibility that sigma-receptors are involved in the motor side effects of antipsychotic drugs.

Activation of protein kinase C by short chain phosphatidylcholines

The acidic phospholipid requirement for protein kinase C (Ca2+/phospholipid-dependent enzyme) activation has been well established, although the molecular nature of this lipid-protein interaction is unclear. The additional requirement for Ca2+ has provided the basis for several models involving charge interactions. We now report that short chain neutral phosphatidylcholines also activate the kinase. Examination of a large series of phosphatidylcholines of varying acyl chain length revealed a close correlation between the ability to form micelles and the ability to support kinase activity. Peak activation occurred in the concentration range just before the critical micelle concentration of each phospholipid. Activation was absolutely dependent on the presence of Ca2+ and diacylglycerol. The possible roles of Ca2+ and phospholipid in the activation process are reexamined in light of these unexpected results.

Correlations between body temperatures, metabolic rate and slow wave sleep in humans

Amounts of slow wave sleep (SWS) in men exposed to either thermoneutral (29 degrees C) or cool (21 degrees C) ambient temperatures were positively correlated with tympanic and rectal temperatures at SWS onset. Decreases in each temperature measure between sleep onset and the nightly termination of SWS were negatively correlated with oxygen consumption during SWS.

Dopamine-independent motor behavior following microinjection of rimorphin in the substantia nigra

The motor-activating effects of rimorphin, an opioid peptide derived from prodynorphin, were examined in the substantia nigra pars reticulata of rats. Unilateral microinjections of rimorphin produced dose-dependent contralateral rotational behavior that was antagonized by naloxone, suggesting that these effects were mediated by opiate receptors. Lesions of midbrain dopamine cells with 6-hydroxydopamine (6-OHDA) produced a 95% or greater depletion of tyrosine hydroxylase in the striatum ipsilateral to the lesion, but failed to reduce the number of circles made by the rats. In addition to an overall preservation of rimorphin-induced circling in animals with 6-OHDA lesions, 50% of these rats exhibited circling that was at least 2 standard deviations above the mean of animals without lesions. The motor activating effects of rimorphin, thus, appear to occur independently of the nigrostriatal dopamine system; these effects may instead be mediated by GABAergic efferents in the pars reticulata.

Phorbol esters increase adenylate cyclase activity and stability in pituitary membranes

In this report, we demonstrate that calcium and phorbol esters enhance cAMP production in GH4C1 cell homogenates. The mechanism for this is a reduction in the rate of decay of adenylate cyclase activity over the course of the assay. Purified protein kinase C can reconstitute calcium- and phorbol ester-dependent adenylate cyclase. Phorbol ester-activated protein kinase C increases both the initial rate of cAMP synthesis and reduces the time-dependent decay of adenylate cyclase activity in membrane preparations. The rate of cAMP production is fit to an equation derived from a model which assumes that adenylate cyclase initially exists in a high activity state which decays exponentially into a low activity state. We suggest that protein kinase C can both prevent the decay of the high activity state and convert the low activity state into the high activity state.