Protective effect of Allium sativum (garlic) aqueous extract against lead-induced oxidative stress in the rat brain, liver, and kidney

The present investigation was undertaken to evaluate the ameliorative activity of Allium sativum against lead-induced oxidative stress in the brain, liver, and kidney of male rats. Four groups of male Wistar strain rats (100-120 g) were taken: group 1 received 1000 mg/L sodium acetate and group 2 was given 1000 mg/L lead acetate through drinking water for 2 weeks. Group 3 and 4 were treated with 250 mg/kg body weight/day of A. sativum and 500 mg/kg body weight/day of A. sativum, respectively, by oral intubation for a period of 2 weeks along with lead acetate. The rats were sacrificed after treatment and the brain, liver, and kidney were isolated on ice. In the brain, four important regions namely the hippocampus, cerebellum, cerebral cortex, and brain stem were separated and used for the present investigation. Blood was also drawn by cardiac puncture and preserved in heparinized vials at 4 °C for estimation of delta-aminolevulinic acid dehydratase (ALAD) activity. The results showed a significant (p < 0.05) increase in reactive oxygen species (ROS), lipid peroxidation products (LPP), total protein carbonyl content (TPCC), and lead in the selected brain regions, liver, and kidney of lead-exposed group compared with their respective controls. Blood delta-ALAD activity showed a significant (p < 0.05) decrease in the lead-exposed rats. However, the concomitant administration of A. sativum resulted in tissue-specific recovery of oxidative stress parameters namely ROS, LPP, and TPCC. A. sativum treatment also restored the blood delta-ALAD activity back to control. Overall, our results indicate that A. sativum administration could be an effective antioxidant treatment strategy for lead-induced oxidative insult.

Susceptibility of Specific Mouse Liver Lobes to Liver Neoplasms Induced with Benzidine Dihydrochloride

The incidence of liver tumors induced in mice with benzidine dihydrochloride was highest in the left lateral lobe, intermediate in the right lateral and central lobes and lowest in the caudate lobe. The distribution of liver tumors was related to lobe volume and weight.

Erectile function recovery in patients after non-nerve sparing radical prostatectomy

Few studies have looked at erectile function recovery (EFR) rates in men undergoing non-nerve sparing resection during radical prostatectomy (RP). Existing studies show great variation in EFR rates owing to multiple factors that minimize their utility in counselling RP patients. We investigated the EFR rate and its predictors in unilateral cavernous nerve resection and bilateral cavernous nerve resection patients 24 months after RP. We conducted a population-based, prospective cohort study of 966 patients who underwent RP at a tertiary cancer centre from 2008 to 2012. Cavernous nerve condition was evaluated on a 4-point nerve sparing score and assigned to one of three groups: bilateral sparing, unilateral resection (UNR) and bilateral nerve resection (BNR). EF was assessed pre-RP and 24-30 months post-op using a validated 5-point patient-reported scale (1 = fully rigid; 5 = no tumescence). EFR was defined as a post-op EF grade of 1-2. Statistical analysis included descriptive statistics, anova, chi-square, Fisher's exact test and logistic regression. Mean baseline EF was 1.84 ± 1.3 and 2.74 ± 1.5 for UNR and BNR patients respectively. Thirty-three percent of UNR patients and 13% of BNR patients exhibited EFR. Age, baseline EF were predictors of EFR. Multivariable analysis showed baseline EF was a significant predictor of EFR at 24 months for UNR. For BNR patients, pre-RP EF was the only factor predictive of EFR. Patients undergoing nerve resection still have a significant chance of achieving true EFR, with UNR surgery patients showing more potential for improvement than patients undergoing BNR surgery. Age and baseline EFR characterize recovery prospects in these two groups. Physicians should thus measure and account for baseline EF in addition to age and the degree of nerve resection when advising patients about expectations for successful EF following RP.

Plant-determined variation in the cardenolide content, thin-layer chromatography profiles, and emetic potency of monarch butterflies,Danaus plexippus L. Reared on milkweed plants in California: 2.Asclepias speciosa

The pattern of variation in gross cardenolide concentration of 111Asclepias speciosa plants collected in six different areas of California is a positively skewed distribution which ranges from 19 to 344 μg of cardenolide per 0.1 g dry weight with a mean of 90 μg per 0.1 g. Butterflies reared individually on these plants in their native habitats ranged from 41 to 547 μg of cardenolide per 0.1 g dry weight with a mean of 179 μg. Total cardenolide per butterfly ranged from 54 to 1279 μg with a mean of 319 μg. Differences in concentrations and total cardenolide contents in the butterflies from the six geographic areas appeared minor, and there were no differences between the males and the females, although the males did weigh significantly more than females. The uptake of cardenolide by the butterflies was found to be a logarithmic function of the plant concentration. This results in regulation: larvae which feed on low-concentration plants produce butterflies with increased cardenolide concentrations relative to those of the plants, and those which feed on high-concentration plants produce butterflies with decreased concentrations. No evidence was adduced that high concentrations of cardenolides in the plants affected the fitness of the butterflies. The mean emetic potencies of the powdered plant and butterfly material were 5.62 and 5.25 blue jay emetic dose fifty units per milligram of cardenolide and the number of ED50 units per butterfly ranged from 0.28 to 6.7 with a mean of 1.67. Monarchs reared onA. speciosa, on average, are only about one tenth as emetic as those reared onA. eriocarpa. UnlikeA. eriocarpa which is limited to California,A. speciosa ranges from California to the Great Plains and is replaced eastwards byA. syriaca L. These two latter milkweed species appear to have a similar array of chemically identical cardenolides, and therefore both must produce butterflies of relatively low emetic potency to birds, with important ecological implications. About 80% of the lower emetic potency of monarchs reared on A. speciosa compared to those reared onA. eriocarpa appears attributable to the higher polarity of the cardenolides inA. speciosa. Thin-layer Chromatographie separation of the cardenolides in two different solvent systems showed that there are 23 cardenolides in theA. speciosa plants of which 20 are stored by the butterflies. There were no differences in the cardenolide spot patterns due either to geographic origin or the sex of the butterflies. As when reared onA. eriocarpa, the butterflies did not store the plant cardenolides withR f values greater than digitoxigenin. However, metabolic transformation of the cardenolides by the larvae appeared minor in comparison to when they were reared onA. eriocarpa. AlthoughA. eriocarpa andA. speciosa contain similar numbers of cardenolides and both contain desglucosyrioside, the cardenolides ofA. speciosa overall are more polar. ThusA. speciosa has no or only small amounts of the nonpolar labriformin and labriformidin, whereas both occur in high concentrations inA. eriocarpa. A. speciosa plants and butterflies also contain uzarigen, syriogenin, and possibly other polar cardenolides withR f values lower than digitoxin. The cardenolide concentration in the leaves is not only considerably less than inA. eriocarpa, but the latex has little to immeasurable cardenolide, whereas that ofA. eriocarpa has very high concentrations of several cardenolides. Quantitative analysis ofR f values of the cardenolide spots, their intensities, and their probabilities of occurrence in the chloroform-methanol-formamide TLC system produced a cardenolide fingerprint pattern very different from that previously established for monarchs reared onA. eriocarpa. This dispels recently published skepticism about the predictibility of chemical fingerprints based upon ingested secondary plant chemicals.

Managing nutrients across regions of the United States

Nutrient balance in the ecosystem involves profitability of the agricultural enterprise and commitments to resource management to maintain quality of air, water, and land resources. Phosphorus and N are the two nutrients of major concern, and they behave differently in soils. Most P adheres strongly to soil particles and moves laterally with the soil during erosion processes, but with high concentrations more P remains in soluble forms and moves in the water fraction. Most N is soluble and moves laterally or downward with soil water. Soil scientists and agronomists have researched soil processes, plant nutrition, cropping systems, and water quality issues mainly on a field and farm level, but now the movement is to management and regulation of nonpoint problems on a watershed basis as proposed in the Clean Water Action Plan. The plan recognizes the vast diversity of soil parent materials and climates among geographic areas, even among and within watersheds, that determine crop adaptation and cropping systems, the role of states in regulatory processes, and the need for local citizens to have operational involvement. This process insures that nutrient management guidelines will be more site-specific and solutions can be focused on the direct problem. Directed efforts will be needed to educate local citizens, landowners, and caretakers of agricultural enterprises, and regulatory agencies. Several factors, including economic and social incentives for implementation must be considered along with the technologies available. The solutions are multidisciplinary, will require long-term research to accommodate climate variation, and should be associated with a strong commitment to education. Public funding will be needed to support the effort.

Involvement of substance P and central opioid receptors in morphine modulation of the CHS response

Morphine administration prior to challenge with the antigen 2,4-dinitro-fluorobenzene increases the contact hypersensitivity (CHS) response in rats. The present study extended these findings by showing that central, but not systemic, administration of N-methylnaltrexone antagonized the morphine-induced enhancement of the CHS response. The importance of the neuroimmune mediator substance P was shown via the attenuation of the morphine-induced enhancement following both systemic and topical administration of the NK-1 antagonist WIN51,708. Taken together, the findings of the present study provide new data showing that central opioid receptors and peripheral substance P are involved in the morphine-induced enhancement of the CHS response.

Morphine modulation of the contact hypersensitivity response: characterization of immunological changes

Previous investigations in our laboratory showed that systemic morphine administration 1 h prior to elicitation of the in vivo contact hypersensitivity (CHS) response produced a robust increase in inflammation at the site of antigen reexposure. The present study extended those findings by characterizing the effect of morphine on immunological processes important in the development of the CHS response. To induce contact hypersensitivity, the antigen 2,4-dinitrofluorobenzene was applied to the pinnae of previously sensitized rats. Morphine administration produced an increase in inducible nitric oxide synthase mRNA and the proinflammatory cytokine interleukin-6, at the site of antigen reexposure. In contrast, morphine did not alter expression of the anti-inflammatory cytokine interleukin-10. Morphine also produced an increase in the proliferation of lymphocytes from the peripheral (i.e., cervical) lymph nodes when assessed 72 h following challenge. These studies show that the morphine-induced increase in the in vivo CHS response involves immunologically specific alterations.

Depression, hopelessness, and desire for hastened death in terminally ill patients with cancer

CONTEXT

Understanding why some terminally ill patients desire a hastened death has become an important issue in palliative care and the debate regarding legalization of assisted suicide.

OBJECTIVES

To assess the prevalence of desire for hastened death among terminally ill cancer patients and to identify factors corresponding to desire for hastened death. Design Prospective survey conducted in a 200-bed palliative care hospital in New York, NY.

PATIENTS

Ninety-two terminally ill cancer patients (60% female; 70% white; mean age, 65.9 years) admitted between June 1998 and January 1999 for end-of-life care who passed a cognitive screening test and provided sufficient data to permit analysis.

MAIN OUTCOME MEASURE

Scores on the Schedule of Attitudes Toward Hastened Death (SAHD), a self-report measure assessing desire for hastened death among individuals with life-threatening medical illness.

RESULTS

Sixteen patients (17%) were classified as having a high desire for hastened death based on the SAHD and 15 (16%) of 89 patients met criteria for a current major depressive episode. Desire for hastened death was significantly associated with a clinical diagnosis of depression (P=.001) as well as with measures of depressive symptom severity (P<.001) and hopelessness (P<.001). In multivariate analyses, depression (P=.003) and hopelessness (P<.001) provided independent and unique contributions to the prediction of desire for hastened death, while social support (P=.05) and physical functioning (P=.02) added significant but smaller contributions.

CONCLUSIONS

Desire for hastened death among terminally ill cancer patients is not uncommon. Depression and hopelessness are the strongest predictors of desire for hastened death in this population and provide independent and unique contributions. Interventions addressing depression, hopelessness, and social support appear to be important aspects of adequate palliative care, particularly as it relates to desire for hastened death.

Naltrexone administration attenuates surgery-induced immune alterations in rats

Surgery is a commonly performed procedure which produces substantial alterations in immune function in both humans and animals. To better understand the mechanism of surgery-induced immunomodulation, the present study investigated the effect of the opioid antagonist naltrexone on surgery-induced immune alterations in rats. Based on previous investigations in our laboratory, rats underwent a 6-cm laparotomy with no internal manipulation and immunological assessments were completed 24 h following the surgical procedure. Naltrexone was administered at the time of surgery and every 4 h thereafter until immune assessment. Results showed that naltrexone attenuated the surgery-induced decrease in natural killer cell cytotoxicity, B-cell proliferation, T-cell proliferation, and production of the cytokine IFN-gamma. These results are among the first to show that pharmacological antagonism of opioid receptors can prevent deleterious immune changes in the postoperative state, suggesting a detrimental role of the endogenous opioids in surgical procedures.

pH dependence of formation of a partially unfolded state of a Lys 73 --> His variant of iso-1-cytochrome c: implications for the alkaline conformational transition of cytochrome c

The alkaline conformational transition of a lysine 73 --> histidine variant of iso-1-cytochrome c has been studied. The transition has been monitored at 695 nm, a band sensitive to the presence of the heme-methionine 80 bond, at the heme Soret band which is sensitive to the nature of the heme ligand, and by NMR methods. The guanidine hydrochloride dependence of the alkaline conformational transition has also been monitored. The histidine 73 protein has an unusual biphasic alkaline conformational transition at both 695 nm and the heme Soret band, consistent with a three-state process. The conformational transition is fully reversible. An equilibrium model has been developed to account for this behavior. With this model, it has been possible to obtain the acid constant for the trigger group, pK(H), of the low-pH phase from the equilibrium data. A pK(H) value of 6.6 +/- 0.1 in H(2)O was obtained, consistent with a histidine acting as the trigger group. The NMR data for the low-pH phase of the alkaline conformational transition are consistent with an imidazole ligand replacing Met 80. For the high-pH phase of the biphasic alkaline transition, the NMR data are consistent with lysine 79 being the heme ligand. Guanidine hydrochloride m values of 1.67 +/- 0.08 and 1.1 +/- 0.2 kcal mol(-1) M(-1) were obtained for the low- and high-pH phases of the biphasic alkaline transition of the histidine 73 protein, respectively, consistent with a greater structural disruption for the low-pH phase of the transition.

Cloning and functional analysis of sucrose:sucrose 1-fructosyltransferase from tall fescue

Enzymes of grasses involved in fructan synthesis are of interest since they play a major role in assimilate partitioning and allocation, for instance in the leaf growth zone. Several fructosyltransferases from tall fescue (Festuca arundinacea) have previously been purified (Lüscher and Nelson, 1995). It is surprising that all of these enzyme preparations appeared to act both as sucrose (Suc):Suc 1-fructosyl transferases (1-SST) and as fructan:fructan 6(G)-fructosyl transferases. Here we report the cloning of a cDNA corresponding to the predominant protein in one of the fructosyl transferase preparations, its transient expression in tobacco protoplasts, and its functional analysis in the methylotrophic yeast, Pichia pastoris. When the cDNA was transiently expressed in tobacco protoplasts, the corresponding enzyme preparations produced 1-kestose from Suc, showing that the cDNA encodes a 1-SST. When the cDNA was expressed in P. pastoris, the recombinant protein had all the properties of known 1-SSTs, namely 1-kestose production, moderate nystose production, lack of 6-kestose production, and fructan exohydrolase activity with 1-kestose as the substrate. The physical properties were similar to those of the previously purified enzyme, except for its apparent lack of fructan:fructan 6(G)-fructosyl transferase activity. The expression pattern of the corresponding mRNA was studied in different zones of the growing leaves, and it was shown that transcript levels matched the 1-SST activity and fructan content.

Endomorphin-1 induces antinociception without immunomodulatory effects in the rat

RATIONALE

Although there is evidence that central opioid receptors are involved in immunomodulation, it has been only recently that an endogenous agonist, designated endomorphin-1, possessing high selectivity and affinity for the mu opioid receptor has been identified.

OBJECTIVE

The present study assesses the immunomodulatory effects of endomorphin- in the rat and provides further evaluation of the antinociceptive effects of endomorphin-1.

METHODS

Rats were surgically implanted with cannulae directed at the lateral cerebral ventricle. Animals received vehicle or endomorphin-1 at doses of 31.63 or 56.23 microg (ICV) and were tested for antinociception in two different assays, the warm water tail withdrawal procedure and the hotplate assay. Additional studies assessed the effect of naltrexone on the antinociception produced by endomorphin-1 in both antinociceptive assessments. Assessments of immune status following endomorphin-1 treatment included measurements of splenic natural killer cell activity, production of interferon-y, and lymphocyte proliferative responses to mitogenic stimulation by Con-A, LPS, and the microbial superantigen, TSST-1.

RESULTS

Endomorphin-1 induced significant and naltrexone reversible antinociception 30 and 60 min following drug administration, as measured by the hotplate assay and warm water tail withdrawal procedure. In marked contrast, endomorphin-1 did not produce immunomodulatory effects up to 120 min following ICV administration.

CONCLUSIONS

Endomorphin-1 produces antinociception but does not induce immunomodulatory effects in the rat. These findings suggest that it is possible to develop therapeutic strategies for separating antinociception and immunomodulatory properties through the mu opioid receptor.

Involvement of central mu- but not delta- or kappa-opioid receptors in immunomodulation

Studies completed in both humans and animals have shown that opioids have significant effects on the immune system via pharmacological interactions with the opioid receptor. However, the type of opioid receptor at which morphine binding produces changes in immune status has not been well characterized. To determine the type of opioid receptor involved in opioid-induced immune alterations, the present study assessed the effects of agonists selective for the mu-, delta-, and kappa-opioid receptors. The site of action (i.e., peripheral vs central) at which opioids produce immune changes was investigated by injecting the agonists directly into the left lateral ventricle of the brain. Specifically, Lewis rats received an intracerebroventricular administration of [d-Ala(2),N-Me-Phe(4), Gly-ol(5)]enkephalin (DAMGO), a mu-receptor selective agonist, [D-Pen(2,5)]enkephalin (DPDPE), a delta-opioid receptor agonist, or U69,593, a kappa-receptor agonist. Immune assessments completed 1 h following drug administration showed that the mu-receptor selective agonist DAMGO produced a dose-dependent decrease in natural killer cell activity and T-lymphocyte proliferation to the mitogen concanavalin A (Con A); no immunological changes were found following DPDPE or U69,593 treatment. Calculation of the number of white blood cells per sample showed no differences between rats treated with saline and rats treated with any of the selective agonists. Administration of the opioid antagonist N-methylnaltrexone prior to DAMGO treatment attenuated the DAMGO-induced changes in immune status. Results from the present study indicate that the immunomodulatory effects of opioids can be attributed to interactions with the mu-opioid receptor.

The schedule of attitudes toward hastened death: Measuring desire for death in terminally ill cancer patients

BACKGROUND

The authors examined the reliability and validity of the Schedule of Attitudes toward Hastened Death (SAHD), a self-report measure of desire for death previously validated in a population of individuals with the acquired immunodeficiency syndrome (AIDS), among terminally ill patients with cancer.

METHODS

The authors interviewed 92 terminally ill cancer patients, all with a life expectancy of < 6 months, after admission to a palliative care hospital. Patients were administered the SAHD, a clinician-rated measure of desire for death (the Desire for Death Rating Scale [DDRS]), and several measures of physical and psychosocial well-being.

RESULTS

The average number of SAHD items endorsed was 4. 76 (standard deviation, 4.3); 15 patients (16.3%) endorsed > or = 10 items, indicating a high desire for death. Internal consistency was strong (coefficient alpha = 0.88, median item-total correlation = 0. 49), as were indices of convergent validity. Total SAHD scores were correlated significantly (correlation coefficient [r] = 0.67) with the DDRS, and somewhat less so with measures of depression (r = 0. 49) and hopelessness (r = 0.55). Lower, but substantial, correlations were observed between the SAHD and measures of spiritual well-being (r = -0.42), quality of life (r = -0.36), physical symptoms (r = 0.38), and symptom distress (r = 0.38). No significant correlation was observed between SAHD scores and social support (r = -0.06) or pain intensity (r = 0.16); however, pain-related functional interference and overall physical functioning were correlated significantly with SAHD scores (r = 0.31 and r = -0.23, respectively).

CONCLUSIONS

The SAHD appears to be a reliable and valid measure of desire for death among terminally ill cancer patients. Coupled with previous research in patients with AIDS, these results support the utility of the SAHD for research addressing interest in hastened death in patients with a life-threatening medical illness.

Phenotypic and functional assessments of immune status in the rat spleen following acute heroin treatment

Heroin use is associated with an increased incidence of several types of infections, including HIV. Yet few studies have assessed whether heroin produces pharmacological alterations of immune status that might contribute to the increased rate of infections amongst heroin users. The present study investigated whether a single administration of heroin to rats produces dose-dependent alterations in functional measures of immune status and in the distribution of leukocyte subsets in the spleen. The results showed that heroin produces a dose-dependent, naltrexone-reversible suppression of the concanavalin A-stimulated proliferation of T cells, lipopolysaccharide-stimulated proliferation of B cells, production of interferon-gamma and cytotoxicity of natural killer (NK) cells in the spleen. Heroin's suppressive effect on NK cell activity results in part from a heroin-induced decrease in the relative number of NKR-P1A(hi) CD3- NK cells in the spleen. Heroin also decreases the percent of a splenic granulocyte subset, the CD11b/c+ HIS48(hi) cells, whose function currently is unknown. In contrast, heroin does not alter relative numbers of CD4+ CD3+ T cells, CD8+ CD3+ T cells, CD45+ B cells, NKR-P1A(lo) CD3+ T cells, CD11b/c+ ED1+ (or CD11b/c+ HIS48-) monocytes/macrophages or CD11b/c+ ED1- (or CD11b/c+ HIS48+) total granulocytes in the spleen. Collectively, these findings demonstrate that heroin produces pharmacological effects on functional and phenotypic measures of immune status.

Topics of conflict between parents and young adolescents

ISSUES AND PURPOSE

Parents often examine and question interactions with their young teen and may ask the advice of healthcare professionals. Topics, frequency, and intensity of conflicts between young adolescents and parents were therefore examined.

DESIGN AND METHODS

A descriptive survey using the 44-item Issues Checklist (Robin, 1975) with 163 parent and young adolescent (ages 11-14) dyads.

RESULTS

Parents and teens were congruent about their reports of the topics, frequency, and intensity of conflict. Discussion of the topics generally was not angry. Mothers reported the greatest quantity of issues. Potentially sensitive topics such as substance use, dating, and sex were rarely approached by either parent or young adolescent. Sociodemographic characteristics did not distinguish or were not associated with IC scores.

PRACTICE IMPLICATIONS

Conflict is a common component of the parent-young adolescent relationship. Families with children entering adolescence can expect conflict about issues that recur but usually are not that "hot". Anticipating topics may put conflict in perspective. Nurses help families resolve conflicts associated with day-to-day conflicts as a first step toward opening up larger, potentially sensitive topics.

Enhancement of the contact hypersensitivity reaction by acute morphine administration at the elicitation phase

The present study investigated the effects of morphine on the irritant contact sensitivity (ICS) and contact hypersensitivity (CHS) reaction. ICS was induced by croton oil application on the pinnae of naïve rats. Morphine injected prior to croton oil application did not affect the ICS response when assessed by measurements of pinnae thickness. CHS was induced by applying the antigen 2,4-dinitro-1-fluorobenzene (DNFB) to the pinnae of rats sensitized to DNFB. Rats received an injection of morphine prior to either initial antigen exposure (sensitization) or antigen reexposure (challenge). Morphine prior to challenge, but not sensitization, resulted in a pronounced enhancement of the CHS response as measured by pinna thickness. Quantitative PCR also showed increased IFN-gamma mRNA levels in the inflamed tissue of morphine-treated rats. Naltrexone blocked the morphine-induced enhancement of the CHS response. The differential effects of morphine suggest that opioids have a more pronounced effect on in vivo immune responses that involve immunological memory.

Severity, time, and beta-adrenergic receptor involvement in surgery-induced immune alterations

Although investigations of surgical stress in animals have reported immune alterations, surprisingly little is known about the variables or mechanisms contributing to the effect. Thus, we completed a series of experiments investigating the immune-altering effects of surgery severity, time of maximal immune alterations, and recovery, as well as the involvement of beta-adrenergic receptors in surgery-induced immune alterations in Lewis rats. Immune alterations included natural killer (NK) cell cytotoxicity as well as B- and T-cell proliferation. Results showed increased immune suppression with larger incisions (6 cm > 3 cm > anesthesia > saline). In addition, maximal immune alterations induced by surgery occurred after 24 h; anesthesia effects predominated at the earlier time points. Recovery of immune status varied depending on the immunological measure of interest. Although NK cell cytotoxicity returned to control values within 2 days, B-cell proliferation remained suppressed for at least 8 days, and T-cell proliferation did not begin to recover until 4-8 days following the surgical procedure. To assess the mechanisms involved in surgery-induced immune alterations, follow-up assessments evaluated the effect of nadolol, a beta-adrenergic receptor antagonist, on surgery-induced immune alterations. Results show that nadolol blocks the surgery-induced reduction in B- and T-cell proliferation but has no effect on the suppression of NK cell cytotoxicity. These results indicate the need to consider surgical severity and postoperative time of immune assessment when investigating the immune-altering effects of surgery. Importantly, activation of beta-adrenergic receptors appears to play a modulatory role in surgery-induced immune alterations.

A dose-response study of chronic cocaine on maternal behavior in rats

To determine if there was a dose-response relationship with regard to cocaine treatment and maternal behavior exhibited by lactating rats at doses that had not been previously investigated, we examined the effects of three doses of chronic cocaine administration throughout gestation on both onset and established maternal behavior. Dams were injected (SC) with 6.3, 13, or 25 mg/kg cocaine HCl or an equivalent volume of saline throughout gestation; maternal behavior was tested on postpartum days 1 and 3. At the doses employed, cocaine disrupted the onset of only one pup-directed component of maternal behavior significantly in a dose-response manner, although there were several statistically nonsignificant dose-dependent trends of behavioral disruptions. No pup-directed behaviors were disrupted during testing for established maternal behavior. These results indicate that gestational cocaine treatment at doses of 25 mg/kg and less have only minimal effects on the onset and no effect on the maintenance of maternal behavior using our paradigm. The relationship of the present findings to previous work is discussed.

Gender differences in factor structure of the Self-Administered Alcoholism Screening Test

Recent studies have revealed differences between men and women alcoholics in symptoms, consequences, and help-seeking behavior related to alcohol usage. Based on these findings, it was hypothesized that gender differences also would appear on alcohol screening instruments. The Self-Administered Alcoholism Screening Test (Colligan, Davis, & Morse, 1988: SAAST: Swenson & Morse, 1975) of 1,920 men and 1,775 women was subjected to a within-gender, principle-components, factor analysis with a varimax rotation. Gender differences at the component level were revealed. Men endorsed the "help-seeking for alcohol-related problems" component while women endorsed the "help-seeking for emotional problems" component. In addition, men expressed concern about receiving a psychiatric label while women expressed concern about receiving a drinker label. The results suggest that different items need to be used in screening women for alcohol-related problems.

Characterization and use of a recombinant retroviral system for the analysis of drug resistant HIV

A recombinant retroviral system was used for the analysis of early HIV breakthrough infection in the presence of antiviral drugs. The use of replication-defective HIV allowed a quantitative analysis of a single cycle of infection. This report characterizes this recombinant HIV system and demonstrates it's validity in comparison to standard assays. It is demonstrated that the protease inhibitor XM323 inhibits both early and late events in the HIV life-cycle, while dextran sulphate inhibits only early events. In addition, it is shown that this system can be used for detecting and quantitating drug resistant HIV. Thus, the use of this system may provide both novel information about the stage of the viral life-cycle inhibited and a preliminary assessment of the mechanism(s) responsible for breakthrough infection in the presence of antiretroviral drugs.

Dose-dependent effects of multiple acute cocaine injections on maternal behavior and aggression in Sprague-Dawley rats

Rat dams, which had no prior drug treatment, were either nontreated controls or were injected subcutaneously 4 times during a 10-day period with a single dose of 30, 15 or 7.5 mg/kg of cocaine hydrochloride HCl, or normal saline. Injections were given immediately postpartum following delivery of their final pup (PPD 1), and again on postpartum day 3 (PPD 3), postpartum day 6 (PPD 6) and postpartum day 10 (PPD 10). Dams were observed 30 min following injections for maternal behavior (MB) towards 8 surrogate male pups on PPD 1 and PPD 3 and for aggression towards a male or female intruder in the presence of their litter on PPD 6 and PPD 10. Compared to saline and untreated controls, cocaine-treated dams exhibited more disruptions in MB on both PPD 1 and PPD 3 and were less aggressive towards an intruder, regardless of intruder sex, on PPD 6 and PPD 10. In most cases MB was altered in a dose-dependent manner with the higher doses of cocaine resulting in a greater disruption of behavior.

Comparison of the time course of morphine's analgesic and immunologic effects

Morphine, an opioid analgesic commonly prescribed and abused, produces immune-altering effects. Whether morphine's antinociceptive and immunologic effects occur concurrently is unknown. Therefore, we investigated the time course of morphine's immunologic and antinociceptive effects. Rats were given a 15-mg/kg morphine injection (subcutaneously), and experimental assessments were taken at 30 min, 1 h, 2 h, 6 h, 12 h, and 24 h after treatment. Immune measures included natural killer (NK) cell activity, proliferation of splenic T and B lymphocytes, and cytokine production. Antinociception was assessed by using the tail withdrawal assay. Results show that morphine's immunomodulatory effects on NK cell activity begin within 30 min, continue for at least 12 h, and return to control values by 24 h. In contrast, proliferation of splenic T and B cells and interferon-gamma production are not altered within 30 min; maximal suppression occurs at 1 h, and recovery begins within 2 h. In all immune measures, therefore, maximal suppression is present at the 1-h time point, and recovery is complete within 24 h. Morphine induces antinociception 30 min to 2 h after drug administration; recovery is complete within 6 h. These results suggest the possibility that different mechanisms modulate morphine's immunologic and analgesic effects.

IMPLICATIONS

Acute morphine treatment in rats produces immune alterations and antinociception. Although there are slight differences in morphine's maximal immunological and antinociceptive effects, morphine suppresses immune status at time points concordant with its antinociceptive effects. These effects should be considered when administering morphine to patients whose systems are immunocompromised.

Daily fluoxetine administration impairs avoidance learning in the rat without altering sensory thresholds

1. Male rats given daily intraperitoneal injections of fluoxetine (10 mg/kg) were slower to escape foot shock by jumping a low barrier. 2. When switched to a shuttle task requiring two crosses to terminate shock, the FLU-treated animals failed to learn in 55 trials. 3. A second experiment found FLU-treated animals could learn a one-way avoidance response, but were significantly slower to learn than control animals. 4. FLU-treated animals were no different than controls on tests of sensory thresholds for foot shock or heat. 5. Tests of motor behaviors revealed no differences in latency to traverse a narrow beam to reach a goal box, however FLU-treated animals were less active in an open field. 6. Several hypotheses can account for these data, the most promising being that a central motivational system (fear) is less active in FLU-treated animals.

Epidemiology, preventive services, and illnesses of international travelers

Medical preparation of travelers to overseas locations is an important part of military medical care. We reviewed pre-travel records of patients attending the travel clinic at the National Naval Medical Center (NNMC) and used a post-travel questionnaire to determine the most frequent medical problems associated with international travel. Among 1,416 individuals who received pre-travel care at NNMC, there were 760 (54%) males and 656 (46%) females, the median patient age was 48 years, the most common reason for travel was pleasure, and the median duration of travel was 21 days. The most common destinations were Asia (27%), Africa (15%), Europe (13%), Central America/Caribbean (12%), and South America (11%). The median number of immunizations prescribed was three. Malaria chemoprophylaxis was prescribed to 45%. The average cost of vaccines and medications to medically prepare a traveler was $67. Among 271 (82%) who returned the post-travel questionnaire, the most common illnesses reported were diarrhea (23%) and upper respiratory infections (19%); medical treatment was sought by 9%. Properly informed, military physicians can provide a valuable service at a reasonable cost to reduce the risk of travel-acquired medical problems and illnesses.

Fructosyltransferase Activities in the Leaf Growth Zone of Tall Fescue

High concentrations of water-soluble carbohydrates, mainly fructan, accumulate in the growth zone of tall fescue (Festuca arundinacea Schreb.) leaf blades. We studied sucrose-hydrolyzing activities in the leaf growth zone because of their importance in carbohydrate partitioning. Sucrose hydrolysis in the basal 1.5 cm was largely due to fructosyltransferases, which had activities up to 10 times higher than in fully developed leaf tissue. Three fructosyltransferases (F1, F2, and F3) were purified from the leaf growth zone. Each synthesized, from either sucrose or 1-kestose, a mixture of trisaccharides and higher-order oligofructans identical with the low-degree of polymerization fructan extracted from similar plant tissue. The highly purified fructosyltransferases retained ability (13%) to transfer fructose from sucrose to water. Time-dependent and substrate-dependent studies, using sucrose as the substrate, showed proportional production of fructose and glucose, indicating that both products are from the same enzyme. Fructosyltransferase was calculated to contribute about half the total transfer of fructose to water in the basal 1.5 cm. Invertase activity increased to near 2.0 cm when fructosyl transfer to sucrose and other oligofructans decreased. Invertase was the major activity for sucrose hydrolysis at positions distal to 3.0 cm.

Sanctuary growth of human immunodeficiency virus in the presence of 3'-azido-3'-deoxythymidine

Human immunodeficiency virus (HIV) resistance to the nonnucleoside reverse transcriptase inhibitors emerges very rapidly under selection in culture and in patients. In contrast, zidovudine (3'-azido-3'-deoxythymidine [AZT])-resistant HIV generally emerges in patients only after more-prolonged therapy. Although HIV can be cultured from many patients shortly after the initiation of AZT treatment, characterization of the virus that is cultured generally indicates that it is sensitive to AZT. To initiate an evaluation of the mechanisms contributing to early HIV breakthrough in the presence of AZT and other nucleoside analogs, we have utilized replication-defective HIV encoding reporter genes. These recombinant HIV allow a quantitative analysis of a single cycle of infection. Results with these defective HIV indicate that early infection in the presence of AZT often results from the infection of a cell which is refractory to the antiretroviral effects of AZT. Characterization of a cell line derived from one such cell has demonstrated decreased accumulation of AZT triphosphate, increased phosphorylation of thymidine to thymidine triphosphate, and increased levels of thymidine kinase activity. In addition, AZT inhibition of replication-competent HIV infection is also significantly impaired in this cell line. Attempts to detect and characterize the mechanisms responsible for early viral infection after initiation of AZT therapy may result in the development of new strategies for prolonged suppression of viral infection prior to the emergence of drug-resistant virus.

Response of Fructan to Water Deficit in Growing Leaves of Tall Fescue

Changes in dry matter and water-soluble carbohydrate components, especially fructan, were examined in the basal 25 mm of expanding leaf blades of tall fescue (Festuca arundinacea Schreb.) to assess their roles in plant response to water deficit. Water was withheld from vegetative plants grown in soil in controlled-environment chambers. As stress progressed, leaf elongation rate decreased sooner in the light period than it did in the dark period. The decrease in growth rate in the dark period was associated with a decrease in local relative elongation rates and a shortening of the elongation zone from about 25 mm (control) to 15 mm. Dry matter content of the leaf base increased 23% during stress, due mainly to increased water-soluble carbohydrate near the ligule and to increased water-soluble, carbohydrate-free dry matter at distal positions. Sucrose content increased 258% in the leaf base, but especially (over 4-fold) within 10 mm of the ligule. Hexose content increased 187% in the leaf base. Content of total fructan decreased to 69% of control, mostly in regions farther from the ligule. Fructan hydrolysis could account for the hexose accumulated. Stress caused the osmotic potential to decrease throughout the leaf base, but more toward the ligule. With stress there was 70% less direct contribution of low-degree-of-polymerization fructan to osmotic potential in the leaf base, but that for sucrose and hexose increased 96 and 67%, respectively. Thus, fructan metabolism is involved but fructan itself contributes only indirectly to osmotic adjustment.

Epidermal cell division and the coordination of leaf and tiller development

Initiation and development of grass leaves and tillers are often described individually with little attention to possible interrelationships among organs. In order to better understand these interrelationships, this research examined epidermal cell division during developmental transitions at the apical meristem of tall fescue (Festuca arundinacea Schreb.). Ten seedlings were harvested each day for a 9-d period, and lengths of main shoot leaves and primary tillers were measured. In addition, numbers and lengths of epidermal cells were determined for 0.5 mm segments along the basal 3 mm of each leaf and tiller. Primordia development and onset of rapid leaf elongation were characterized by an increase in the number of cells per epidermal file with mean cell length remaining near 20 microm per cell. After the leaf had lengthened to 1-1.5 mm, cells near the leaf tip ceased dividing and increased in length, at which time leaf elongation rate increased rapidly. Ligule formation, marking the boundary between blade and sheath cells, occurred prior to leaf tip emergence above the whorl of older sheaths, while the earliest differentiation between blade and sheath cells probably began when leaves were < 1 mm long. Major transitions in leaf and tiller development appeared to be synchronized among at least three adjacent nodes. At the oldest node, cessation of cell division in the leaf sheath was accompanied by initiation of cell division and elongation in the associated tiller bud. At the next younger node the ligule was being initiated, while at the youngest node cell division commenced in the leaf primordium, as elongation of a new leaf blade began. This synchronization of events suggests a key role for the cell division process in regulating leaf and tiller development.

Epidermal cell division and the coordination of leaf and tiller development

Initiation and development of grass leaves and tillers are often described individually with little attention to possible interrelationships among organs. In order to better understand these interrelationships, this research examined epidermal cell division during developmental transitions at the apical meristem of tall fescue (Festuca arundinacea Schreb.). Ten seedlings were harvested each day for a 9-d period, and lengths of main shoot leaves and primary tillers were measured. In addition, numbers and lengths of epidermal cells were determined for 0.5 mm segments along the basal 3 mm of each leaf and tiller. Primordia development and onset of rapid leaf elongation were characterized by an increase in the number of cells per epidermal file with mean cell length remaining near 20 microm per cell. After the leaf had lengthened to 1-1.5 mm, cells near the leaf tip ceased dividing and increased in length, at which time leaf elongation rate increased rapidly. Ligule formation, marking the boundary between blade and sheath cells, occurred prior to leaf tip emergence above the whorl of older sheaths, while the earliest differentiation between blade and sheath cells probably began when leaves were < 1 mm long. Major transitions in leaf and tiller development appeared to be synchronized among at least three adjacent nodes. At the oldest node, cessation of cell division in the leaf sheath was accompanied by initiation of cell division and elongation in the associated tiller bud. At the next younger node the ligule was being initiated, while at the youngest node cell division commenced in the leaf primordium, as elongation of a new leaf blade began. This synchronization of events suggests a key role for the cell division process in regulating leaf and tiller development.

Nitrogen Use within the Growing Leaf Blade of Tall Fescue

Leaf elongation rate (LER) of grasses depends on N supply and is expressed mostly through cell production, whereas most N in mature leaf tissues is chloroplastic. Our objective was to evaluate a possible competition for N between cell production and chloroplast development processes, utilizing the gradient of cell development along the leaf growth zone of tall fescue (Festuca arundinacea Schreb.). Under the two contrasting N regimes, total N content was highest in the cell production zone, declined sharply as cells elongated, and remained relatively constant in more distal positions, at values close to those measured in mature tissues. A similar pattern was found for N in proteins and nucleic acids that were not soluble in 80% ethanol. Content of N compounds soluble in 80% ethanol was higher in the cell production and elongation zones than in mature parts of the leaf. NO3- N content was low in the cell production zone and increased in the cell elongation zone for high-N plants. The deposition rate of total N in the growth zone was much higher with plants in high N than in those shifted to no N. For both N regimes, most N was deposited during cell production and early cell elongation. Little N was deposited during cell maturation where ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) was being actively synthesized. This suggests that synthesis of Rubisco, and probably other chloroplastic proteins, occurs largely from recycling of N that was previously incorporated into proteins during cell production. Thus, Rubisco content in mature tissues is more closely associated with N deposited during cell production than with N deposited during its biosynthesis.

Recombinant retroviral systems for the analysis of drug resistant HIV

Two recombinant retroviral systems are described that can be used to analyze antiretroviral drug activity and HIV breakthrough (replication in the presence of the drug). The first system utilizes a recombinant HIV encoding beta-galactosidase as a reporter gene (HIV-LacZ). The defective HIV-LacZ virus is produced in COS cells after co-transfection of a plasmid encoding the HIV-LacZ genome with a plasmid encoding HIV proteins necessary for packaging and infectivity. Subsequent infection of CD4+ target cells, followed by assay for LacZ expression, permits the rapid identification of individual virus-infected cells. This system can be used to quantitate the inhibition of early events in the HIV replicative cycle and is suitable for the screening of compounds for anti-HIV activity. However, this system cannot be used to analyze HIV drug resistance because of the limited genetic heterogeneity of the virus that is produced in COS cells. To circumvent this problem, a second system has been developed in which heterogenous recombinant HIV is produced by rescue with replication-competent 'helper' HIV. This system required the production of CD4+ cell lines containing defective proviruses encoding either LacZ or guanosine phosphoribosyl transferase (gpt). The defective proviruses are rescued by infection of the cell lines with 'helper' HIV and used to infect target cells in the presence of antiretroviral agents. Subsequent reporter gene assay is used to identify virus-infected cells. This system has been used to detect rare HIV breakthrough infection of cells in the presence of the non-nucleoside reverse transcriptase inhibitor TIBO R82150. Similar analyses with other antiretroviral agents, alone and in combination, may help identify therapeutic strategies that minimize breakthrough replication of HIV.

Developmental toxicity of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T). I. Multireplicated dose-response studies in four inbred strains and one outbred stock of mice

A large-scaled multireplicated developmental toxicity study was conducted in various strains/stocks of mice with the herbicide, 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), by gavage on Gestational Days 6 through 14. The most important attributes of the study design were replicated test groups, a minimum of four dose levels per replicate, use of multiple stocks/strains of animals to obtain an estimate of the range in sensitivities due to genotype, complete pathological evaluation of maternal animals, and histopathological as well as teratological evaluation of the fetuses. Developmental toxicity was observed at doses below those producing discernible or measurable maternal toxicity. Regression and/or probit analyses were conducted to determine whether a dose-response relationship existed. Reduced fetal weight and increased incidence of cleft palate and embryolethality were the most significant prenatal effects of 2,4,5-T exposure observed in this study. Each strain/stock exhibited a dose-related decrease in fetal weight with the CD-1 mice having the steepest slope and the A/J mice having the shallowest slope. There was a striking similarity among the slopes of the dose-response curves for the various strains/stocks. The mean incidence of embryolethality in the A/J strain was significantly greater than that of the other strains or stocks. There was substantial variation among replicates within strains. The use of the replicated study design was logistically necessary due to the magnitude of the study and it also served to increase the statistical power of the study.

Developmental toxicity of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T). II. Multireplicated dose-response studies with technical and analytical grades of 2,4,5-T in four-way outcross mice

A series of multireplicated developmental toxicity studies were conducted in four-way outcross mice and CD-1 outbred mice administered either analytical or technical grades of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) by gavage on Gestational Days 6 through 14. The formulations of 2,4,5-T differed by a factor of 10-fold in 2,3,7,8-tetrachlorodibenzo-p-dioxin levels. Reduced fetal weight and increased incidences of cleft palate and embryolethality were the most significant prenatal effects of both formulations of 2,4,5-T observed in all strains/stocks of mice. Both the outcross and outbred mice exhibited a dose-response relationship with each of the above endpoints and the dose-response curves were parallel. There were no embryotoxic or fetotoxic differences between the technical and analytical grades of 2,4,5-T with regard to extent of fetal weight reduction, resorption rate, or cleft palate incidence. There was little difference in the results between the four-way outcross mouse and the CD-1 outbred mouse.

Peroxidase Activity in the Leaf Elongation Zone of Tall Fescue : II. Spatial Distribution of Apoplastic Peroxidase Activity in Genotypes Differing in Length of the Elongation Zone

Previous work suggested that cell wall peroxidase activity increased as cells were displaced through the elongation zone in leaf blades of tall fescue (Festuca arundinacea Schreb.). In this study, two genotypes that differ in length of the elongation zone were used to examine the relationship between peroxidase activity in apoplastic fluid of intact leaf blade segments and the spatial distribution of leaf growth. Apoplastic fluid was extracted by vacuum infiltration and centrifugation, and peroxidase activity was assayed spectrophotometrically. Isoelectric focusing was used to characterize the isoforms of apoplastic peroxidase within the region of elongation and in the region of secondary cell wall deposition, which is distal to the elongation zone. A striking correlation was found in each genotype between both the location and timing of increase in apoplastic peroxidase activity and the onset of growth deceleration. Only cationic isoforms of apoplastic peroxidase could be identified in the elongation zone, whereas additional anionic isoforms appeared in the region of secondary cell wall deposition. We conclude that cessation of elongation growth in tall fescue leaf blades is likely to be related to the secretion of cationic isoforms of peroxidase into the cell wall.

Peroxidase activity in the leaf elongation zone of tall fescue : I. Spatial distribution of ionically bound peroxidase activity in genotypes differing in length of the elongation zone

Cessation of cell expansion has been associated with cell wall cross-linking reactions catalyzed by peroxidase. This study utilized two genotypes of tall fescue (Festuca arundinacea Schreb.) that differ in length of the leaf elongation zone to investigate the relationship between ionically bound peroxidase activity and the spatial distribution of leaf elongation. Peroxidase activity was also localized histochemically in transverse sections of the leaf blade using 3,3' -diaminobenzidine. Soluble or soluble plus ionically bound peroxidase activities were extracted from homogenized segments of the elongating leaf blade and assayed spectrophotometrically. Activity of the ionically bound fraction, expressed per milligram fresh weight or per microgram protein, increased as cells were displaced through the distal half of the elongation zone, corresponding to the region in which the elongation rate declined. In both genotypes, the initial increase in activity preceded the onset of growth deceleration by about 10 hours. In the basal region where elongation began, histochemical localization showed that peroxidase activity was found only in vascular tissues. As cells were displaced farther through the elongation zone, peroxidase activity appeared in walls of other longitudinally continuous tissues such as the epidermis and bundle sheaths. Increase in ionically bound peroxidase activity and changes in localization of peroxidase activity occurred at comparable developmental stages in the two genotypes. The results indicate that cessation of elongation followed an increase in cell wall peroxidase activity.