Neuropeptides differentially effect various forms of morphine tolerance

Two different forms of tolerance to morphine were shown to develop. One form, environment dependent (ED), was associated with cues paired with the arrival of the drug. The second form of tolerance, environment independent (EI), was not dependent on any cues. ED tolerance was induced using a multiple injection model in which a cue (orange scent) preceeded each morphine injection (ip). After 12 days the animals were tolerant to the i.p. injection. However if morphine was injected i.c.v. tolerance was no longer evident. EI tolerance was induced by a pellet implant method. These animals were tolerant to morphine regardless of the route of administration. Peptides arginine vasopressin (AVP) and cyclo (Leu-Gly) (cLG) were tested for their ability to alter tolerance. AVP was found to facilitate the development of ED tolerance but had no effect on EI tolerance. On the other hand cLG blocked the development of EI tolerance without affecting ED tolerance. The determination of brain morphine levels indicated that the ED tolerance produced by this method is dispositional while EI tolerance is functional.

Reducing occurrences of an asymmetrical tonic neck reflex

A custom-designed foam rubber headpiece was used during lunch with a multiply handicapped child to reduce the occurrences of an asymmetrical tonic neck reflex. After the inappropriate reflex was inhibited, the apparatus was gradually faded out by cutting away sections of the rubber. Ultimately, the headpiece was completely eliminated and the asymmetrical tonic neck reflex maintained a zero level of occurrence during lunch periods. Concomitantly, there was an increase in correct bites of food.

Characteristics of receptors and enzymes in brains of human alcoholics

Acute and chronic ethanol administration to animals has been shown to produce changes in the turnover of numerous neurotransmitters, as well as to change the characteristics of certain neurotransmitter receptors. In the present study, brains obtained from human alcoholics and matched control subjects were examined for similar changes. In frontal cortex, the affinity of opiate receptors for dihydromorphine was significantly reduced in brains of alcoholics. Judging from animal studies, this change may reflect alterations in opiate receptor-effector coupling processes. No changes were observed in muscarinic cholinergic or beta-adrenergic receptors in humans, in contrast to animals, possibly because of the protracted abstention from alcohol among the alcoholic patients prior to death. Similarly, no changes in the activities of choline acetyltransferase, tyrosine hydroxylase or MAO-B were observed in brains of alcoholics as compared to the control population. Our studies suggest that many of the alterations witnessed during alcohol intoxication and withdrawal in animals may be more subtle in humans, or may be reversible with abstinence.

Ethanol's effects on cortical adenylate cyclase activity

The effects of ethanol on beta-adrenergic receptor-coupled adenylate cyclase (AC) of mouse cerebral cortex were examined. The addition of ethanol (20-500 mM) to incubation mixtures containing cortical membranes demonstrated that ethanol could increase AC activity and potentiate the stimulatory effects of guanylyl-imidodiphosphate [Gpp(NH)p] on AC activity. Ethanol increased the rate of activation of AC by guanine nucleotides and concomitantly decreased the EC50 for magnesium required to achieve maximal stimulation of cortical AC. The EC50 values for Gpp(NH)p and isoproterenol stimulation of AC activity were also altered by ethanol. Ethanol was capable of stimulating AC extracted by use of digitonin. The AC activity in the digitonin extract was no longer sensitive to the addition of Gpp(NH)p or NaF, but was still stimulated by ethanol. We propose multiple sites of action for ethanol in stimulating cortical AC activity. These sites include actions at the beta-adrenergic receptor, at the G/F coupling proteins, and at the catalytic unit of cortical AC. Comparison of ethanol's actions on cortical beta receptor coupled AC activity with prior reported actions of ethanol on striatal dopamine (DA)-sensitive AC indicated differential sensitivities of these two AC systems to ethanol. These differences may be determined by specific coupling characteristics of the striatal and cortical AC systems or by differences in the plasma membranes in which striatal and cortical AC systems are located.

The effects of acute and chronic morphine on regional distribution of cardiac output in brain

Both acute and chronic administration of morphine resulted in an increase in the percent cardiac output received by brain. However, various brain regions were affected differently by the drug treatments. The greatest increases in percent cardiac output received after chronic administration of morphine occurred in pons and cerebellum, while the greatest increases after acute administration occurred in cortex and midbrain. The changes found are in contrast with earlier studies which suggest that morphine has no effect on cerebral blood flow.

Primary colorectal signet-ring cell carcinoma in young patients: report of 3 cases

Three cases of primary signet-ring cell carcinoma of the rectum are described. They accounted for 0.2% of the 1531 cases of colorectal adenocarcinoma in the 12 yr period from 1972-1983 in the University Department of Pathology at Queen Mary Hospital. The patients were young, aged 18, 24 and 27 yr respectively, in striking contrast to the mean age of 62 in patients with the usual types of colorectal cancer. They were also younger than most patients with this tumour in the literature. They presented with alteration of bowel habit, blood and mucus in stool, and weight loss. Pathological features included constrictive narrowing of the gut lumen by intestinal wall thickened by a desmoplastic reaction to diffusely infiltrating signet-ring carcinoma cells, widespread lymph node and peritoneal metastases, and absent hepatic metastasis. Microscopically, the mucosa was largely intact, but had multifocal tumour involvement. This peculiar feature was responsible for three consecutive negative biopsies in one case. Care in distinguishing it from mucinous adenocarcinoma is emphasized. All three patients presented with Dukes' C lesions. The prognosis is poor.

Ethanol inhibits the activity of the B form of monoamine oxidase in human platelet and brain tissue

Ethanol selectively inhibits the activity of the B-form of monoamine oxidase (MAO) in membranes obtained from human platelet and brain. When endogenous concentrations of phenylethylamine are used as substrate, significant inhibition is induced by concentrations of ethanol that are attainable after ethanol ingestion (50 mM). The mechanism of ethanol's inhibition of MAO activity appears to involve perturbation of membrane lipids surrounding the enzyme.

Production and purification of murine monoclonal antibodies: aberrant elution from protein A-Sepharose 4B

A rapid, one-step method for the efficient purification of murine monoclonal antibodies from tissue culture supernatants is described. This process is based on affinity chromatography on protein A-Sepharose columns. It was found that murine monoclonal antibodies raised against tick-borne encephalitis virus frequently eluted at more than one pH value and these pH values did not always correspond to those of antibodies of the same subclass from polyclonal mouse sera. The two populations of antibody molecule eluting at different pH values showed no variation in molecular weight, isoelectric profiles, specific enzyme-linked immunosorbent assay titer, or antibody subclass.

Mechanical suitability of glycerol-preserved human dura mater for construction of prosthetic cardiac valves

We have examined the tensile viscoelastic properties of fresh and glycerol-preserved human dura mater, and correlated the results with structural information from the scanning electron microscope. The interwoven laminar structure of dura produces rather high flexural stiffness, while the crossed-fibrillar laminae produce planar mechanical isotropy. Glycerol storage shifts the stress-strain curve to lower strain, reduces stress relaxation and creep, and lowers the ultimate tensile strength and strain at fracture. These changes may be due to glyceraldehyde crosslinking, or to increased interfibrillar friction. The latter hypothesis suggests that glycerol storage may reduce the fatigue lifetime of the tissue.

Isolation of the human insulin-like growth factor I gene using a single synthetic DNA probe

A single synthetic oligonucleotide was employed as hybridization probe to detect and enable isolation of the human insulin-like growth factor I (IGF-I) gene from a human genomic DNA library. The synthetic oligonucleotide probe coded for the B-chain of IGF-I and was designed for expression in Escherichia coli. Despite numerous interspersed mismatches, the synthetic probe hybridized specifically with seven recombinant lambda phage containing almost the entire B-chain region of the human IGF-I gene. The usefulness of this approach was further demonstrated by the detection of lambda phage containing human preproinsulin, using A and B chain synthetic oligonucleotides, 90 and 63 nucleotides in length, as hybridization probes. The nucleotide sequence of the human IGF-I exon suggests that IGF-I is synthesized as a larger precursor molecule.

What does a bar of soap have to do with health care marketing?

In today's competitive health care market, product/service marketing will become the key to survival. This article introduces a new way of using an established marketing concept. Product/service marketing is based on promoting services that fulfill a number of requirements, including being highly visible and a foundation for the later development of an overall marketing plan. Choosing the products/services to be marketed and developing the marketing program are discussed.

Antigenic variation among members of the tick-borne encephalitis complex

The antigenic relationships between seven members of the tick-borne encephalitis complex of flaviviruses (group B arboviruses) were examined by raising a library of 16 monoclonal antibodies against one of them and examining their biological and antigenic properties. These clones reacted with only one of two intracellular, virus-specific polypeptides. One polypeptide [mol. wt. 58 X 10(3) (58K)] is related to the major envelope protein E, but the identity of the other is at present unknown, even though it is a major immunogen in experimental infections and vaccinations. Only those clones specific for the 58K polypeptide contain either neutralizing or haemagglutinin-inhibiting activity, but these epitopes are not identical. In general, epitopes on the 51K polypeptide were more heavily conserved than those on the 58K polypeptide, although both conserved and variant epitopes were found on both polypeptides. One epitope was present on the 51K polypeptide which was conserved on all seven isolates studied and another epitope on the same polypeptide was specific for all the western isolates including one isolate of louping-ill virus. Using the monoclonal antibodies raised in the study, it was shown that louping-ill virus was closely related antigenically to isolates of the Western subtype of tick-borne encephalitis virus.

The glutaraldehyde-stabilized porcine aortic valve xenograft. I. Tensile viscoelastic properties of the fresh leaflet material

The tensile viscoelastic properties of radial and circumferential strips of fresh porcine aortic valve leaflets have been examined and compared with the fiber architecture of the leaflets as seen in the scanning electron microscope. The leaflet material showed nonlinear viscoelasticity, largely independent of strain rate, and dependent on the degree of preconditioning by cyclic loading. Preconditioning to a stable stress-strain response could only be accomplished on 1-cm-long strips above a minimum width of 4 mm (circumferential) and 6 mm (radial). Preconditioning yielded a more elastic and extensible material with reduced hysteresis. The leaflets were markedly anisotropic. Circumferential strips were up to 8 times stronger and stiffer than radial strips, and displayed greater stress relaxation and less creep. The circumferential mechanical properties were due to well-aligned circumferential collagen bundles reinforcing the composite structure, while radial properties were due to a more random collagenous support throughout the leaflet. Despite the presence of a septal shelf on the right coronary leaflet, no mechanical differences could be discerned between leaflets.

Cyclo(Leu-Gly) has opposite effects on D-2 dopamine receptors in different brain areas

Cyclo(Leu-Gly) (cLG), a diketopiperazine analog of Pro-Leu-Gly-NH2 (MIF), affects a number of physiological and behavioral responses to the endogenous neurotransmitter, dopamine (DA). In the present series of experiments, the effect of in vivo administration of cLG (8 mg/kg) was investigated five days following subcutaneous administration. It was found that cLG administration of cLG (8 mg/kg) was investigated five days following subcutaneous administration. It was found that cLG administration caused a supersensitive behavioral response, measured by increased stereotypic sniffing, to the DA agonist, apomorphine (APO). At the same time, an increase was found in the affinity for dopamine (DA), as measured by dopamine inhibition of 3H-spiroperidol binding to D-2 DA receptors in striatum (nigro-striatal DA tract). In contrast, the same peptide treatment caused a subsensitive physiological response to APO-induced hypothermia, concomitant with a decrease in affinity for dopamine, as measured by DA inhibition of 3H-spiroperidol binding to D-2 DA receptors in hypothalamus (incerto-hypothalamic DA tract). These results suggest that a single neuromodulatory agent, the peptide cLG, can elicit diametrically opposite effects on D-2 DA receptors and on the corresponding physiological endpoints in two different brain areas.

The glutaraldehyde-stabilized porcine aortic valve xenograft. II. Effect of fixation with or without pressure on the tensile viscoelastic properties of the leaflet material

We have examined the tensile viscoelastic properties of circumferential and radial strips of porcine aortic valve leaflets following fixation in glutaraldehyde and formaldehyde, with or without pressure. After aldehyde treatment, the radial strips remained weaker and less stiff than circumferential strips and responded slightly differently to the treatment. After fixation, with or without pressure, the radial strips showed large changes in stress-strain and hysteresis responses due to initial loading, and there was a twofold reduction in tensile strength and final stiffness. For strips in both directions, fixation without pressure produced doubled extensibility and a ramping stress-strain curve. Permanent (plastic) deformation of 5-20% occurred as a result of cyclic loading, stress relaxation, and creep experiments. Pressure fixation, however, produced little change in stress-strain results other than a simple shift to lower strain and produced no plasticity. Both methods of fixation reduced stress relaxation and creep. Mechanical test results are consistent with a loss of ground substance matrix during fixation. Reductions in tensile strength after fixation may be due to "riveting" of collagen geometry, producing local stress concentrations.

[Anesthesia for transsternal thymectomy in myasthenia gravis]

Twenty-seven patients with generalized myasthenia gravis (moderate, severe and acute fulminating forms) who underwent thymectomy were studied. The effects of several anesthetic agents were analyzed with special attention being given to immunologic considerations. The authors conclude that the association of ketamine, tiapride, droperidol, fentanil and nitrous oxide allowed fast recovery of consciousness and spontaneous respiration, and made safe extubation possible before leaving the operating room.

A model for design of health administration curriculum and instruction

Faculty members in health administration programs as in other professional programs tend to be trained in content appropriate to their field rather than as educators. Enhancement of the teaching skills of faculty will potentially improve the quality of the students' educational experience. Of particular note is the tendency of faculty to teach at the basic knowledge level and expect students to perform at the application and problem-solving levels. The purpose of this paper is to aid faculty in health administration improve their teaching activities and student evaluation. This goal will be accomplished through presentation of a model for systematic design of curriculum application of this model at the course and lesson levels.

Alcohol dehydrogenase isozymes in grain sorghum (Sorghum bicolor): evidence for a gene duplication

Two sets of alcohol dehydrogenase (ADH) bands are regularly observed in grain sorghum (Sorghum bicolor): set I is a permanent triplet; set II is variable, as either two or three bands. A faint set III is detected only when extracts from seeds subjected to anaerobiosis are run in neutral pH gels. Dissociation-reassociation experiments reveal that the central band of the set I triplet is a heterodimer of the other two. Full-sib progeny analysis from self-fed plants shows that the set II bands are doublets, with heterozygotes having only three apparent bands instead of four because of the similar mobilities of the fast-migrating isozyme specified by the slow allele and the slow isozyme specified by the fast allele. We propose a three-locus model as the best explanation of these patterns. Set I consists of the products of two loci and their intergenic heterodimer. Set III is specified by a third locus. Set II isozymes are the intergenic heterodimers of the two set I loci and the set III locus. This explanation is similar to that of Schwartz and Freeling for maize but suggests that the evolution of Sorghum includes a gene duplication of the homologue of the Adh-1 locus in Zea.

Cyclo(Leu-Gly) attenuates the striatal dopaminergic supersensitivity induced by chronic morphine: agonist binding to D2 dopamine receptors correlates with stereotypic behavior

We have previously shown that MIF and its structural analog, cyclo-(Leu-Gly), block analgesic tolerance and some signs of physical dependence following chronic opiate administration. The mechanism of action of these peptides has not been clearly elucidated. The data presented here suggests that chronic opiate administration causes a behavioral supersensitivity to dopamine (DA) agonists which is highly correlated with an increase in D2-Hi receptor affinity for DA agonists, but not antagonists. Both the behavioral and receptor changes are blocked by prior administration of cyclo(Leu-Gly). This suggests that the ability of cyclo(Leu-Gly) to block the development of opiate addictive states may involve DA synaptic elements.

Peptide inhibition of morphine-induced dopaminergic supersensitivity

Injection of the peptide cyclo(Leu-Gly) into rats prior to chronic exposure to morphine, inhibits: 1) the development of analgesic tolerance; 2) some signs of physical dependence; and, 3) morphine-induced increases in behavioral responses to dopamine agonists. Although there was no change in the total number of high affinity striatal dopamine receptors, chronic morphine treatment did increase the affinity of the ligand at the receptor. The peptide blocked not only the affinity change, but the increased behavioral response to apomorphine as well. These behavioral changes correlate significantly with the neurochemical changes in dopamine receptors following chronic morphine treatment. Therefore, some of the pharmacological efforts of morphine may be mediated by changes in CNS dopamine receptors and that the peptides may act by inhibiting these neurochemical changes.