Continuous oral olanzapine or clozapine treatment initiated in adolescence has differential short- and long-term impacts on antipsychotic sensitivity than those initiated in adulthood

One of the major discoveries in recent research on antipsychotic drugs is that antipsychotic treatment in adolescence could induce robust long-term alterations in antipsychotic sensitivity that persist into adulthood. These long-term impacts are likely influenced by various factors, including the "diseased" state of animals, sex, type of drugs, mode of drug administration, and age of treatment onset. In this study we compared the short- and long-term behavioral effects of 21-day continuous oral olanzapine (7.5 mg/kg/day) or clozapine (30.0 mg/kg/day) administration in heathy or maternal immune activated adolescent (33-53 days old) or adult (80-100 days old) rats of both sexes. We used a conditioned avoidance response model to assess the drug-induced alterations in antipsychotic sensitivity. Here, we report that while under the chronic drug treatment period, olanzapine progressively increased its suppression of avoidance responding over time, especially when treatment was initiated in adulthood. Clozapine's suppression depended on the age of drug exposure, with treatment initiated in adulthood showing a suppression while that initiated in adolescent did not. After a 17-day drug-free interval, in a drug challenge test, olanzapine treatment initiated in adolescence caused a decrease in drug sensitivity, as reflected by less avoidance suppression (a tolerance effect); whereas that initiated in adulthood appeared to cause an increase (more avoidance suppression, a sensitization effect). Clozapine treatments initiated in both adolescence and adulthood caused a similar tolerance effect. Our findings indicate that the same chronic antipsychotic treatment regimen initiated in adolescence or adulthood can have differential short- and long-term impacts on drug sensitivity.

Long-term impacts of prenatal maternal immune activation and postnatal maternal separation on maternal behavior in adult female rats: Relevance to postpartum mental disorders

Early life adversities are known to exert long-term negative impacts on psychological and brain functions in adulthood. The present work examined how a prenatal brain insult and a postnatal stressor independently or interactively influence the quality of maternal care of postpartum female rats and their cognitive and emotional functions, as a way to identify the behavioral dysfunctions underlying childhood trauma-induced postpartum mental disorders (as indexed by impaired maternal care). Sprague-Dawley female offspring born from mother rats exposed to polyinosinic:polycytidylic acid (PolyI:C, 4.0-6.0 mg/kg) intended to cause gestational maternal immune activation (MIA) or saline were subjected to a repeated maternal separation stress (RMS, 3 h/day) or no separation for 9 days in the first two weeks of life (a 2 × 2 design). When these offspring became mothers, their attentional filtering ability (as measured in the prepulse inhibition of acoustic startle reflex test), positive hedonic response (as measured in the sucrose preference test), and negative emotional response (as measured in the startle reflex and fear-potentiated startle test) were examined, along with their home-cage maternal behavior. Virgin littermates served as controls in all the behavioral tests except in maternal behavior. Results showed that mother rats who experienced RMS displayed impaired nest building and crouching/nursing activities. RMS also interacted with MIA to alter pup retrieval latency and startle reactivity, such that MIA-RMS dams demonstrated significantly slower pup retrieval latency and higher startle magnitude compared to either RMS-only and MIA-only mothers. MIA also disrupted attentional filtering ability, with significantly lower prepulse inhibition. However, neither prenatal MIA nor postnatal RMS impaired sucrose preference or the acquisition of fear-potentiated startle. These results indicate that prenatal stress and postnatal adversity could impair maternal behavior individually, and interact with each other, causing impairments in attention, emotion and maternal motivation.

Terminal type-specific cannabinoid CB1 receptor alterations in patients with schizophrenia: A pilot study

BACKGROUND

Individuals with schizophrenia are at elevated genetic risks for comorbid cannabis use, and often experience exacerbations of cognitive and psychotic symptoms when exposed to cannabis. These findings have led a number of investigators to examine cannabinoid CB1 receptor (CB1R) alterations in schizophrenia, though with conflicting results. We recently demonstrated the presence of CB1R in both excitatory and inhibitory boutons in the human prefrontal cortex, with differential levels of the receptor between bouton types. We hypothesized that the differential enrichment of CB1R between bouton types - a factor previously unaccounted for when examining CB1R changes in schizophrenia - may resolve prior discrepant reports and increase our insight into the effects of CB1R alterations on the pathophysiology of schizophrenia.

METHODS

Using co-labeling immunohistochemistry and fluorescent microscopy, we examined total CB1R levels and CB1R levels within excitatory (vGlut1-positive) and inhibitory (vGAT-positive) boutons of prefrontal cortex samples from ten pairs of individuals (nine male pairs and one female pair) diagnosed with schizophrenia and non-psychiatric comparisons.

RESULTS

Significantly higher total CB1R levels were found within samples from individuals with schizophrenia. Terminal type-specific analyses identified significantly higher CB1R levels within excitatory boutons in samples from individuals with schizophrenia relative to comparisons. In contrast, CB1R levels within the subset of inhibitory boutons that normally express high CB1R levels (presumptive cholecystokinin neuron boutons) were lower in samples from individuals with schizophrenia relative to comparison samples.

CONCLUSION

Given CB1R's role in suppressing neurotransmission upon activation, these results suggest an overall shift in excitatory and inhibitory balance regulation toward a net reduction of excitatory activity in schizophrenia.

Terminal type-specific cannabinoid CB1 receptor alterations in patients with schizophrenia: a pilot study

Background

Individuals with schizophrenia are at elevated genetic risks for comorbid cannabis use, and often experience exacerbations of cognitive and psychotic symptoms when exposed to cannabis. These findings have led a number of investigators to examine cannabinoid CB1 receptor (CB1R) alterations in schizophrenia, though with conflicting results. We recently demonstrated the presence of CB1R in both excitatory and inhibitory boutons in the human prefrontal cortex, with differential levels of the receptor between bouton types. We hypothesized that the differential enrichment of CB1R between bouton types - a factor previously unaccounted for when examining CB1R changes in schizophrenia - may resolve prior discrepant reports and increase our insight into the effects of CB1R alterations on the pathophysiology of schizophrenia.

Methods

Using co-labeling immunohistochemistry and fluorescent microscopy, we examined total CB1R levels and CB1R levels within excitatory (vGlut1-positive) and inhibitory (vGAT-positive) boutons of prefrontal cortex samples from ten pairs of individuals diagnosed with schizophrenia and non-psychiatric comparisons.

Results

Significantly higher total CB1R levels were found within samples from individuals with schizophrenia. Terminal type-specific analyses identified significantly higher CB1R levels within excitatory boutons in samples from individuals with schizophrenia relative to comparisons. In contrast, CB1R levels within the subset of inhibitory boutons that normally express high CB1R levels (presumptive cholecystokinin neuron boutons) were lower in samples from individuals with schizophrenia relative to comparison samples.

Conclusion

Given CB1R's role in suppressing neurotransmission upon activation, these results suggest an overall shift in excitatory and inhibitory balance regulation toward a net reduction of excitatory activity in schizophrenia.

East Asian Population

This article explores the ways East Asian American (EAA) children and adolescents have experienced disparities in the United States throughout the COVID-19 pandemic. The history of racism toward Asian American and Pacific Islanders (AAPI) and the complexities of acculturation are reflected through this contemporary lens. Traditional East Asian (EA) values were disrupted during this period. Implications for children and families are discussed. Persistent underlying xenophobia and racism, such as the model minority myth or perpetual foreigner stereotype, rose to new prominence, furthering emotional distress in EA and EAA youths beyond those already experienced universally by AAPI families during the pandemic.

Addressing Discrimination Against Asian American and Pacific Islander Youths: The Mental Health Provider's Role

Asian American and Pacific Islanders (AAPI) are the fastest growing racial minority in the United States. With more than 40 subgroups in the diaspora, 1 in 10 American youths will be of Asian origin by 2060. Racism-defined as prejudice, discrimination or antagonism on the basis of membership in a particular racial or ethnic group-is increasingly recognized as a public health crisis.1 Anti-AAPI racism, such as unequal resource distribution in housing, education, employment, and health care, exclusionary naturalization policies and violence1,2 (eg, Pacific coast riots, Japanese Americans' internment during World War II, recent Atlanta shootings) is well documented. Anti-AAPI microaggressions-that is, the subtle, sometimes unintentional forms of racism such as characterizations as perpetual foreigners, ascriptions of intelligence, oversexualization of women, invalidated interethnic differences, and model minority myth-are common. The model minority stereotype dismisses real struggles1 and pits AAPIs against other racial minorities. Despite the proud tradition of AAPI activism , discrimination is often endured in silence, probably stemming from cultural values of stoicism and harmony, and tacit societal acceptance of racism.3.

The molecular basis of spinocerebellar ataxia type 48 caused by a de novo mutation in the ubiquitin ligase CHIP

The spinocerebellar ataxias (SCAs) are a class of incurable diseases characterized by degeneration of the cerebellum that results in movement disorder. Recently, a new heritable form of SCA, spinocerebellar ataxia type 48 (SCA48), was attributed to dominant mutations in STIP1 homology and U box-containing 1 (STUB1); however, little is known about how these mutations cause SCA48. STUB1 encodes for the protein C terminus of Hsc70 interacting protein (CHIP), an E3 ubiquitin ligase. CHIP is known to regulate proteostasis by recruiting chaperones via a N-terminal tetratricopeptide repeat domain and recruiting E2 ubiquitin-conjugating enzymes via a C-terminal U-box domain. These interactions allow CHIP to mediate the ubiquitination of chaperone-bound, misfolded proteins to promote their degradation via the proteasome. Here we have identified a novel, de novo mutation in STUB1 in a patient with SCA48 encoding for an A52G point mutation in the tetratricopeptide repeat domain of CHIP. Utilizing an array of biophysical, biochemical, and cellular assays, we demonstrate that the CHIPA52G point mutant retains E3-ligase activity but has decreased affinity for chaperones. We further show that this mutant decreases cellular fitness in response to certain cellular stressors and induces neurodegeneration in a transgenic Caenorhabditis elegans model of SCA48. Together, our data identify the A52G mutant as a cause of SCA48 and provide molecular insight into how mutations in STUB1 cause SCA48.

Maternal immune activation and repeated maternal separation alter offspring conditioned avoidance response learning and antipsychotic response in male rats

Previous work shows that repeated administration of several commonly used antipsychotic drugs, such as olanzapine (OLZ) over several days, induces an enhanced disruption of conditioned avoidance response (CAR) (termed antipsychotic sensitization) in normal adolescent and adult rats. However, it is unclear whether the same phenomenon can also be demonstrated in rat models of schizophrenia. The present study investigated OLZ sensitization in a combined maternal immune activation (MIA) and repeated maternal separation (RMS) model of schizophrenia. Sprague-Dawley male rats were first subjected to an early prenatal exposure to polyinosinic:polycytidylic acid (PolyI:C) on gestation days 13 (4 mg/kg, iv) and 15 (6 mg/kg, iv). They were then repeatedly separated from their mothers for 3 h daily during the first two weeks of postpartum. After they became adolescent (on postnatal day, PND 43), acute and OLZ sensitization effects in the CAR model was assessed. Adolescent MIA rats showed an impaired acquisition of conditioned avoidance response, but displayed a normal acute OLZ-induced avoidance suppression and OLZ sensitization effect. In adulthood (PND 81), MIA rats again showed an impairment in the acquisition of CAR. However, they showed a reduced response to OLZ (1.0 mg/kg; sc) treatment during the repeated drug test days, indicating a disruption of the induction of OLZ sensitization. In the OLZ sensitization challenge test, both MIA and control rats exhibited a robust and similar sensitization effect. In both adolescence and adulthood, RMS alone had no effect on any of the behavioral outcomes, and combined MIA-RMS even abolished the MIA alone-induced disruption of avoidance acquisition and the induction of OLZ sensitization. These results indicate that MIA disrupts associative learning and may reduce antipsychotic efficacy in the early stage of OLZ treatment. RMS does not appear to affect associative learning and behavioral responses to OLZ, and may possibly attenuate MIA-induced deficits. Our findings demonstrate that OLZ sensitization is a robust phenomenon but its magnitude can be altered by early MIA.

[Multimodality navigation for liver resection of complicated alveolar echinococcosis]

Objective: To investigate the clinical application of multimodality navigation for liver resection in the treatment of complicated alveolar echinococcosis (AE). Methods: From October 2019 to February 2020, the clinical data and perioperative results of patients with AE treated by surgery in our department were retrospectively studied. Hepatic parenchyma disconnection plane and liver resection were navigated and performed with three-dimensional reconstruction and HITACHI real-time multi-image fusion interventional navigation system (RVS). Results: All of six patients were successful performed radical liver resection without mortality. The operation time was (301±106)min and the median blood loss was 200 ml. Two patients needed blood transfusion intraoperative (33.33%). The postoperative hospital stay was (10.8±2.8) day, and the cost of hospitalization was (82 584±995.61) yuan. Clavien-Dindo grade Ⅲ complication occurred in one patient. Conclusions: Multimodality navigation might provide precise intraoperative navigation of the surgical plane and effectively assist liver resection for the treatment of complicated AE.

Factors associated with underrepresented minority physician scientist trainee career choices

BACKGROUND

Recently, there have been concerted efforts to improve racial and ethnic diversity in the physician-scientist workforce. Identifying factors associated with career choices among those underrepresented in medicine and science is a necessary first step to advance this objective. The aim of the present study was to assess the attitudes and factors associated with academic and research career interests among underrepresented predoctoral physician-scientists.

METHODS

A cross-sectional 70-question survey was distributed to all predoctoral single degree (MD or DO) and dual degree (MD/PhD or DO/PhD) trainees at 32 medical schools in the United States from 2012 to 2014. Main outcomes included factors important to advancement in academic medicine, intended medical specialty, and future career plans. To test the post-hoc hypothesis of whether trainees from underrepresented groups have differing perceptions of career trajectories and obstacles than their counterparts, we evaluated responses according to self-identified race/ethnic status using Chi-square and Fisher's exact tests. All tests were two-sided and significance level of < 0.05 was used.

RESULTS

There were a total of 4433 responses representing all predoctoral training stages. The response rate was 27%. Most respondents were single degree trainees (MD/DO 79% vs MD/DO-PhD 21%). Most respondents self-identified as White (67%), followed by Multi-racial or Other (14.3%), Asian or Pacific Islander (10.4%), Hispanic (6%), and Black or African American (4.1%). Desired career sector, career intention, and clinical specialty interest differed across race/ethnic groups. With respect to career selection factors, anticipated non-work related responsibilities during residency were also significantly different between these groups. By multivariable regression analysis, Black or African American trainees were significantly less likely than White trainees to indicate a career in academia (OR 0.496, 95% CI 0.322-0.764) and basic research (OR 0.314, 95% CI 0.115-0.857), while Multi-racial or Other trainees were also less likely than White trainees to indicate a career in academia (OR 0.763, 95% CI 0.594-0.980).

CONCLUSIONS

These data represent the first in-depth survey of career aspirations, perceptions, and interests between demographically underrepresented and non-underrepresented predoctoral physician-scientist trainees. Our results identify key differences between these cohorts, which may guide efforts to improve diversity within the physician-scientist workforce.

[Robotic hilar cholangiocarcinoma radical resection compared with laparotomy in prognosis]

Objective: To compare the long term and short term outcomes between robotic and open surgery for hilar cholangiocarcinoma radical resection. Methods: This is a single-center and retrospective case-control study. Patients underwent hilar cholangiocarcinoma radical resection between January 2016 and December 2016 at Department of Hepatobiliary Surgery of the General Hospital of the Chinese People's Liberation Army were included. Safety, effectiveness and long-term prognosis of tumors were evaluated. Patients were divided into robotic hilar cholangiocarcinoma radical surgery group (robotic group, n=16) and open hepatic hilar cholangiocarcinoma radical surgery group (open group, n=31) . All cases were confirmed by pathology histological. Age, gender, histology, resection margin status, extent of surgical resection, disease-free survival (DFS) , and overall survival (OS) were retrospectively collected and analyzed.In the follow-up cohort, the primary outcome was patient death and the secondary outcome was tumor recurrence. Continuous variables were expressed as means and medians and were compared using the Student t test if normally distributed or Wilcoxon-Mann-Whitney test for nonparametric variables. Discrete variables were expressed as frequency and percentages and χ(2) or Fisher exact test, when appropriate, were used for comparisons. Kaplan-Meier curves were used to calculate the probability of survival and comparisons were performed using log-rank test. Results: In this study, compared with the open group, the robotic group had a longer operation time ( (338±71) minutes vs. (256±56) minutes, t=4.251, P=0.001) , but the intraoperative blood loss was less (100 ml vs. 200 ml, Z=121.50, P=0.040) , the gastric tube removal time was earlier (3 days vs. 4 days, Z=136.0, P=0.011) , and the postoperative hospital stay was shorter (9 days vs. 12 days, Z=144.50, P=0.040) , and the difference was statistically significant.There was no significant difference in the blood transfusion rate, R0 resection rate, and tumor size between the two groups.The recurrence rates in the robotic group and open surgery were 53.3% and 67.0%, respectively (χ(2)=1.04, P=0.307) .The median survival time of the robotic group and the open group was 22.0 months and 25.0 months. There was no significant difference in the overall survival rate between the two groups (P>0.05) . Conclusion: Compared with laparotomy, robotic HCC radical resection could have an equivalence or non-inferiority approach with acceptable long-term outcome.

Vitiligo-like depigmentation in oncology patients treated with immunotherapies for nonmelanoma metastatic cancers

Vitiligo-like depigmentation (VLD) is a characteristic cutaneous event described in patients with metastatic malignant melanoma receiving treatment with immune checkpoint inhibitors. We report the onset of VLD in three patients with other cancer types (cholangiocarcinoma, renal cell carcinoma and squamous cell carcinoma) following treatment with immunotherapy (combination pembrolizumab and nivolumab for the first, and pembrolizumab for the other two cancer types). Cases of VLD have not been reported previously in patients treated for any of these cancers, to our knowledge. Pembrolizumab and nivolumab are monoclonal antibodies targeting programmed cell death (PD)-1 receptors, while ipilimumab targets cytotoxic T-lymphocyte antigen-4. Our clinical finding challenges the current understanding of VLD as a malignant melanoma-specific immunotherapy-related adverse event.

Nicotine- and cocaine-triggered methamphetamine reinstatement in female and male Sprague-Dawley rats

Preclinical studies have demonstrated a return to methamphetamine (meth)-seeking behavior (reinstatement) induced by injections of meth administered by the experimenter (drug-prime). Notably, females tend to be more sensitive to drug-prime; often displaying more reinstatement behavior when compared to males. While meth-primed reinstatement of meth-seeking behavior has been established, little is known about the ability of other drugs of abuse to substitute for meth during drug-primed reinstatement; nicotine and cocaine were the focus of the present work. We also examined if self-administration and/or reinstated meth-seeking behavior was affected by repeated nicotine administration. Male and female Sprague-Dawley rats were trained to self-administer meth during daily sessions. During this self-administration phase, rats were placed into 1 of 2 groups: saline or repeated nicotine exposure. Rats in the repeated nicotine group received nicotine injections 4h after meth self-administration sessions, whereas the remaining rats received saline. Following self-administration was extinction in which meth was no longer available and nicotine was no longer administered. After extinction, rats were tested to determine if 0 (saline), 0.2, and 0.4mg/kg nicotine reinstated meth-seeking behavior. Three days of re-extinction followed nicotine testing. Finally, rats received reinstatement tests with 0 (saline), 5, and 10mg/kg cocaine. Nicotine and cocaine reinstated meth-seeking behavior in male and female rats with no difference between the sexes. Repeated nicotine administration potentiated meth reinstatement following the 0.4mg/kg nicotine-prime. While females may be more sensitive to reinstatement triggered with the original self-administration drug, this effect may not generalize to priming with other drugs of abuse.

The effects of varenicline on methamphetamine self-administration and drug-primed reinstatement in male rats

Methamphetamine (meth) addiction is a costly burden to both the individual user and society as a whole. Establishing effective pharmacotherapies to treat meth dependence is needed to help solve this health problem. The study reported herein examined the effects of varenicline, a partial α4β2 and full α7 nicotinic acetylcholine receptor agonist, on meth self-administration and reinstatement in male Sprague-Dawley rats. Following indwelling jugular catheter surgery, rats were either trained to self-administer meth or saline on a variable ratio (VR) 3 schedule of reinforcement. Self-administration sessions (2h duration; 19 total sessions) were conducted daily. The effect of varenicline pretreatment on meth and saline self-administration was then determined using a within-study design. All rats received varenicline (0.0, 0.3, 1.0, and 3.0mg/kg) prior to 4 different test sessions. Dose order was randomly assigned and each test was separated by 2 standard self-administration sessions to assess stability of responding. Fifteen extinction sessions (no meth available) followed the last test. Extinction was followed by meth-primed (0.3mg/kg IP) reinstatement tests to examine the effect of varenicline on meth-seeking behavior. All rats again received all doses of varenicline over 4 separate reinstatement tests performed on 4 consecutive days. Varenicline did not alter self-administration of meth or saline. Additionally, the 0.3 and 1.0 doses of varenicline non-specifically increased active lever responding during the reinstatement test sessions. This latter finding suggests that varenicline may increase relapse liability and should not be utilized as pharmacotherapy to treat meth dependence.

Collective Deceleration of Laser-Driven Electron Bunches

Few-fs electron bunches from laser wakefield acceleration (LWFA) can efficiently drive plasma wakefields (PWFs), as shown by their propagation through underdense plasma in two experiments. A strong and density-insensitive deceleration of the bunches has been observed in 2 mm of 10^{18}  cm^{-3} density plasma with 5.1  GV/m average gradient, which is attributed to a self-driven PWF. This observation implies that the physics of PWFs, usually relying on large-scale rf accelerators as drivers, can be studied by tabletop LWFA electron sources.

The chemical class of quinazoline compounds provides a core structure for the design of anticytomegaloviral kinase inhibitors

HCMV is a member of the family Herpesviridae and represents a worldwide distributed pathogen with seropositivity rates in the adult population ranging between 40% and 90%. Notably, HCMV infection is a serious, sometimes life-threatening medical problem for newborns and immunosuppressed individuals, including transplant recipients and patients under antitumoral chemotherapy. Current standard therapy with valganciclovir has the disadvantage of inducing drug-resistant virus mutants and toxicity-related side effects. Our analysis stresses the earlier finding that kinase inhibitors of the quinazoline class exert an antiviral response by targeting the viral protein kinase pUL97 without inducing resistance. Therefore, quinazolines have been used as a core structure to gain insight in the mode of inhibitor-kinase interaction. Here, we demonstrate that (i) the novel quinazolines Vi7392 and Vi7453 are highly active against HCMV laboratory and clinically relevant strains including maribavir- and ganciclovir-resistant variants, (ii) antiviral activity is not cell-type specific and was also detected in a placental explant tissue model using a genetically intact HCMV strain (iii) the viral kinase pUL97 represents a target of the anticytomegaloviral activity of these compounds, (iv) induction of pUL97-conferring drug resistance was not detectable under single-step selection, thus differed from the induction of ganciclovir resistance, and (v) pUL97 drug docking simulations enabled detailed insights into specific drug-target binding properties providing a promising basis for the design of optimized kinase inhibitors. These novel findings may open new prospects for the future medical use of quinazoline drug candidates and the use of drug-target dynamic simulations for rational design of antivirals.

Sex differences in neurotensin and substance P following nicotine self-administration in rats

Investigator-administered nicotine alters neurotensin and substance P levels in Sprague-Dawley rats. This finding suggested a role of the dopamine-related endogenous neuropeptides in nicotine addiction. We sought to extend this observation by determining the responses of neurotensin and substance P systems (assessed using radioimmunoassay) in male and female rats following nicotine self-administration (SA). Male and female Sprague-Dawley were trained to self-administer nicotine, or receive saline infusions yoked to a nicotine-administering rat during daily sessions (1-h; 21 days). Brains were extracted 3 h after the last SA session. Nicotine SA increased tissue levels of neurotensin in the males in the anterior and posterior caudate, globus pallidus, frontal cortex, nucleus accumbens core and shell, and ventral tegmental area. Nicotine SA also increased tissue levels of neurotensin in the females in the anterior caudate, globus pallidus, nucleus accumbens core and shell, but not in the posterior caudate, frontal cortex, or ventral tegmental area. There were fewer sex differences observed in the substance P systems. Nicotine SA increased tissue levels of substance P in both the males and females in the posterior caudate, globus pallidus, frontal cortex, nucleus accumbens shell, and ventral tegmental area. A sex difference was observed in the nucleus accumbens core, where nicotine SA increased tissue levels of substance P in the males, yet decreased levels in the females. The regulation of neuropeptides following nicotine SA may play a role in the susceptibility to nicotine dependence in females and males. Synapse 70:336-346, 2016. © 2016 Wiley Periodicals, Inc.

The effects of varenicline on methamphetamine self-administration and drug-primed reinstatement in female rats

While research has revealed heightened vulnerability to meth addiction in women, preclinical models rarely use female subjects when investigating meth seeking and relapse. The goal of the present study was to examine the effects of varenicline (Chantix(®)), a partial α4β2 and full α7 nicotinic acetylcholine receptor agonist, on meth self-administration and reinstatement in female rats. Sprague-Dawley rats were surgically implanted with an indwelling jugular catheter. Half of the rats were then trained to self-administer meth (0.056 mg/kg/infusion) on a variable ratio 3 schedule of reinforcement; the other half earned intravenous saline during daily, 2h sessions. When responding stabilized, varenicline (0.0, 0.3, 1.0, 3.0mg/kg) was tested to determine how it altered meth taking. Varenicline was probed on 4 test days; each test separated by 2 standard self-administration sessions to assure responding remained stable. Following this testing was 15 extinction sessions. Twenty-four hours after the last extinction session were four consecutive days of meth-primed reinstatement. The same 4 doses of varenicline were examined to determine how it altered reinstatement triggered by 0.3mg/kg meth (IP). Rats readily self-administered meth. The higher doses of varenicline did not affect meth-taking in a specific fashion as active lever pressing was also slightly reduced in rats that has access to saline in the self-administration phase. Female rats displayed robust meth-primed reinstatement. Notably, the lower doses of varenicline increased meth-primed reinstatement. This amplified susceptibility to reinstatement (i.e., relapse) may be an impediment for the use of varenicline as a therapeutic to treat meth use disorder.

Adolescent olanzapine sensitization is correlated with hippocampal stem cell proliferation in a maternal immune activation rat model of schizophrenia

Previous work established that repeated olanzapine (OLZ) administration in normal adolescent rats induces a sensitization effect (i.e. increased behavioral responsiveness to drug re-exposure) in the conditioned avoidance response (CAR) model. However, it is unclear whether the same phenomenon can be detected in animal models of schizophrenia. The present study explored the generalizability of OLZ sensitization from healthy animals to a preclinical neuroinflammatory model of schizophrenia in the CAR. Maternal immune activation (MIA) was induced via polyinosinic:polycytidylic acid (PolyI:C) administration into pregnant dams. Behavioral assessments of offspring first identified decreased maternal separation-induced pup ultrasonic vocalizations and increased amphetamine-induced hyperlocomotion in animals prenatally exposed to PolyI:C. In addition, repeated adolescent OLZ administration confirmed the generalizability of the sensitization phenomenon. Using the CAR test, adolescent MIA animals displayed a similar increase in behavioral responsiveness after repeated OLZ exposure during both the repeated drug test days as well as a subsequent challenge test. Neurobiologically, few studies examining the relationship between hippocampal cell proliferation and survival and either antipsychotic exposure or MIA have incorporated concurrent behavioral changes. Thus, the current study also sought to reveal the correlation between OLZ behavioral sensitization in the CAR and hippocampal cell proliferation and survival. 5'-bromodeoxyuridine immunohistochemistry identified a positive correlation between the magnitude of OLZ sensitization (i.e. change in avoidance suppression induced by OLZ across days) and hippocampal cell proliferation. The implications of the relationship between behavioral and neurobiological results are discussed.

Accidental overheating of a newborn under an infant radiant warmer: a lesson for future use

A fully functional radiant warmer induced rapid and continuous increases in regional skin temperatures, heart rate, mean arterial blood pressure and respiratory rate in a newborn patient without corrective action. We report this case of passive overheating to create awareness of the risks associated with regulating radiant heat output based upon a single servo-controlled temperature.

Optimization of microencapsulation parameters: Semipermeable microcapsules as a bioartificial pancreas

An improved membrane has been developed for the microencapsulation of islets of Langerhans which protects these cells from the immune system. These requirements were accomplished through the optimization of important microencapsulation parameters and through the improved biocompatibility of a new alginate-poly-l-lysine (PLL)-alginate capsule membrane. Spherical and smooth microcapsules could be formed by utilizing a purer sodium alginate and by keeping the viscosity of the sodium alginate solution above 30 cps. The strength of the capsule membrane was enhanced by increasing the alginate-PLL reaction time as well as the PLL concentration. The permeability of the membrane [4 mum thick, 93% (w/w) water] was a function of the viscosity average molecular weight (Mv) of the PLL (Mv = 4000-4 x 10(5)) used in the encapsulation procedure. Microcapsules prepared with PLL with Mv = 1.7 x 10(4) were the least permeable, being impermeable to normal serum immunoglobulin, albumin, and haemoglobin. The microencapsulation procedure, by protecting transplanted tissue from the components of the immune system, has great clinical potential as a new form of treatment for diseases such as diabetes and liver disease.

Oral maribavir for treatment of refractory or resistant cytomegalovirus infections in transplant recipients

BACKGROUND

Despite advances in cytomegalovirus (CMV) prophylaxis and therapy, some transplant recipients still develop refractory CMV infections. Maribavir (MBV), an investigational benzimidazole antiviral agent, acts by a mechanism different from that of existing anti-CMV drugs. Previous Phase I and II studies have demonstrated a favorable safety profile for MBV, but its utility in treatment of complex CMV syndromes is unknown.

METHODS

Between June and December 2008, MBV was released for use under individual emergency investigational new drug applications requested by treating physicians and approved by the US Food and Drug Administration and local institutional review boards. Six patients (5 solid organ transplant recipients and 1 hematopoietic stem cell transplant recipient) who had failed to respond to other therapies and/or had known ganciclovir-resistant CMV were treated with MBV at a starting oral dose of 400 mg twice daily.

RESULTS

Patients were treated for a median of 207 days (range, 15-376). Four of 6 patients had no detectable CMV DNAemia within 6 weeks of starting MBV therapy. One patient, who had an initial viral load of 1.8 million copies/mL, developed MBV resistance mutations. One patient, who had low serum levels of MBV, had persistent CMV DNAemia and viruria without developing genotypic or phenotypic resistance to MBV. One patient cleared CMV DNAemia, but died of pneumonia and multiorgan failure. No significant adverse effects attributable to MBV were observed.

CONCLUSIONS

MBV deserves further systematic evaluation as treatment for CMV infection that is resistant and/or refractory to standard therapies, but its optimal dose, duration of therapy, and use in combinations versus as a single agent have yet to be determined.

Is staging beneficial for Fowler-Stephens orchiopexy? A systematic review

PURPOSE

Fowler and Stephens showed that by dividing the spermatic vessels a high intra-abdominal testis could be placed in the scrotum. Testicular atrophy is a potential complication of this technique. We conducted a systematic review to determine whether single or 2-stage Fowler-Stephens orchiopexy results in better testicular viability.

MATERIALS AND METHODS

We searched electronic databases, clinical trial registries and gray literature. We included reports describing boys younger than 18 years with a primary outcome of "testicular viability and position." We performed a meta-analysis using random effects models. Heterogeneity was assessed using forest plot and I(2) statistic.

RESULTS

We identified 1,807 citations and included 61 articles. Single stage Fowler-Stephens orchiopexy was discussed in 9 articles, a 2-stage procedure in 36 and both approaches in 16. There were no randomized controlled trials, and most studies were cohort or case series. The pooled estimate of success rates was 80% for single stage Fowler-Stephens orchiopexy (95% CI 75 to 86) and 85% for 2-stage Fowler-Stephens orchiopexy (95% CI 81 to 90). The pooled odds ratio of single stage vs 2-stage Fowler-Stephens orchiopexy was 2.0 (95% CI 1.1 to 3.9) favoring the 2-stage procedure. There was no difference in the success rate between laparoscopic and open techniques in either single or 2-stage Fowler-Stephens orchiopexy. There was no evidence of asymmetry on the funnel plot. There were no complications reported with single stage, while ileus, hematoma and infection were the most common complications with 2-stage Fowler-Stephens orchiopexy.

CONCLUSIONS

Both techniques have a fairly high success rate but 2-stage Fowler-Stephens orchiopexy appears to carry a higher rate of success than the single stage approach (85% vs 80%, OR 2 in favor of 2-stage). Laparoscopic and open techniques had the same success rate. However, the level of evidence of the studies was low, and a study of a more robust design, such as a randomized controlled trial, should be performed.

Patient and allograft survival of Indo Asian and East Asian dialysis patients treated in Canada

Kidney failure is relatively common among Canadians of Asian origin. However, little is known about the health outcomes after initiation of renal replacement therapy in this population. Our study evaluates differences in the likelihood of renal transplantation and graft loss among Asian and white patients. We studied 21 523 adults of East Asian, Indo Asian or white ethnicity who had initiated dialysis in Canada from 1990-2000. Subjects were followed until death, loss to follow-up or end of study (2004). The proportion of the eligible subjects who were East Asian, Indo Asian, or white was 6, 3, and 91%, respectively. Compared to white patients, East Asian and Indo Asian patients were significantly less likely to receive a renal transplant after adjusting for potential confounding factors. This disparity is greater for transplants from living donors as compared to those from deceased donors. The adjusted death censored graft loss in transplant recipients was not significantly different between ethnic groups. The adjusted risk of death following transplantation, however, was significantly lower in Indo Asian than in white patients. Our findings show that in a Canadian population, patients of East Asian or Indo Asian origin had lower rates of renal transplantation than white patients, especially for living donor transplantation. These findings warrant further study, especially given the good graft outcomes in these individuals.

Expression profiling of the Arabidopsis annexin gene family during germination, de-etiolation and abiotic stress

Annexins are a multigene family in most plant species and are suggested to play a role in a wide variety of essential cellular processes. In Arabidopsis thaliana there are eight different annexins (AnnAt1-8), which range from 29% to 83% in deduced amino acid sequence identity. As a first step toward clarifying the individual functions of these annexins, in this study we have used quantitative real time reverse transcription PCR to assess their differential expression in different tissues or after different stimuli. We determined which annexins are expressed during germination and early seedling growth by assaying annexin expression levels in dry and germinating seeds and in 7-day-old light-grown seedlings. Our results indicate that transcripts for all eight annexins are present in germinating seeds and that transcript levels for all the annexins increase by 7 days of normal growth. We assayed transcript levels in dark grown roots, cotyledons, and hypocotyls and found that the relative abundance of each annexin varied in these dark-grown tissues. We also examined the effects of red and far red light treatments on annexin expression in 5.5-day-old etiolated seedlings. Light treatments significantly altered transcript levels in hypocotyls and cotyledons for only two members of the gene family. Finally, we monitored annexin expression changes in response to a variety of abiotic stresses. We found that the expression of most of the Arabidopsis annexin genes is differentially regulated by exposure to salt, drought, and high- and low-temperature conditions, indicating a likely role for members of this gene family in stress responses.

Human cytomegalovirus glycoprotein N (gpUL73-gN) genomic variants: identification of a novel subgroup, geographical distribution and evidence of positive selective pressure

Human cytomegalvirus (HCMV) ORF UL73 is a polymorphic locus, encoding the viral glycoprotein gpUL73-gN, a component of the gC-II envelope complex. The previously identified gN genomic variants, denoted gN-1, gN-2, gN-3 and gN-4, were further investigated in this work by analysing a large panel of HCMV clinical isolates collected from all over the world (223 samples). Sequencing and phylogenetic analysis confirmed the existence of the four gN genotypes, but also allowed the identification of a novel subgroup belonging to the gN-3 genotype, which was designated gN-3b. The number of non-synonymous (d(N)) and synonymous (d(S)) nucleotide substitutions and their ratio (d(N)/d(S)) were estimated among the gN genotypes to evaluate the possibility of positive selection. Results showed that the four variants evolved by neutral (random) selection, but that the gN-3 and gN-4 genotypes are maintained by positive selective pressure. The 223 HCMV clinical isolates were subdivided according to their geographical origin, and four main regions of gN prevalence were identified: Europe, China, Australia and Northern America. The gN variants were found to be widespread and represented within the regions analysed without any significant difference, and no new genotype was detected. Finally, for clinical and epidemiological purposes, a rapid and low-cost method for genetic grouping of the HCMV clinical isolates was developed based on the RFLP revealed by SacI, ScaI and SalI digestion of the PCR-amplified UL73 sequence. This technique enabled us to distinguish all four gN genomic variants and also their subtypes.

Sequencing of cytomegalovirus UL97 gene for genotypic antiviral resistance testing

The widespread use of ganciclovir (GCV) to treat cytomegalovirus (CMV) infections in immunosuppressed patients has led to the development of drug resistance. Phenotypic assays for CMV drug resistance are presently too time-consuming to be therapeutically useful. To support the development of genotypic assays for GCV resistance, the complete sequences of the UL97 phosphotransferase genes in 28 phenotypically GCV-sensitive CMV clinical isolates were determined. The gene was found to be highly conserved, with nucleotide sequence identity among strains ranging from 98.6 to 100% and amino acid sequence identity of >99%. Primers for a genotypic assay were designed to amplify codons 400 to 707, because all known UL97 mutations conferring drug resistance occur at three sites within this region. This part of the UL97 gene was amplified from over 50 clinical isolates, and two sequencing reactions for the coding strand were successfully used to identify GCV resistance mutations. This genotypic assay can be performed in 48 h using genomic DNA extracted from cell monolayers at very low levels of virus infectivity, thus rapidly providing therapeutically useful results.

Mining time dependency patterns in clinical pathways

Clinical pathways are widely adopted by many large hospitals around the world in order to provide high-quality patient treatment and reduce the length of hospital stay of each patient. The development of clinical pathways is a lengthy process, and may require the collaboration among physicians, nurses, and staffs in a hospital. However, the individual differences cause great variances in the execution of clinical pathways. It calls for a more dynamic and adaptive process to improve the performance of clinical pathways. This paper reports a data mining technique we have developed to discover the time dependency pattern of clinical pathways for managing brain stroke. The mining of time dependency pattern is to discover patterns of process execution sequences and to identify the dependent relation between activities in a majority of cases. By obtaining the time dependency patterns, we can predict the paths for new patients when he/she is admitted into a hospital; in turn, the health care procedure will be more effective and efficient.

Testing of alkaline and enzymatic hydrolysis pretreatments for fat particles in slaughterhouse wastewater

Four pretreatments to hydrolyse and/or reduce the size of fat particles in slaughterhouse wastewater (SHW) were tested: sodium hydroxide and three lipases of plant, bacterial and animal (pancreatic) origin. Hydrolysing agents and SHW containing between 2.5 and 3 g/l of fat particles were mixed at room temperature for 4 h. Additions of 5-400 meq NaOH/l did not increase soluble COD (SCOD) in SHW, but the average particle size was reduced to 73% +/- 7% of the initial average particle size (D(in)) at NaOH concentrations ranging from 150 to 300 meq/l. Pretreatment with pancreatic lipase PL-250 reduced the average particle size to a maximum of 60% +/- 3% of D(in). As D(in) was decreased from 359 to 68 microns, the enzyme concentration required to obtain the maximum particle size reduction increased from 200 to 1000 mg/l. A 4-h pretreatment with PL-250 also increased the free long-chain fatty acid (LCFA) concentration to a maximum of 15.5 mg/l, indicating some solubilization of the pork fat particles in SHW. SCOD was not significantly increased by the pretreatment, but SCOD was not found to be a good indicator of enzymatic lipolysis because of enzyme adsorption on the fat particle surface. Pancreatic lipase appeared more efficient with beef fat than pork fat, possibly because beef fat contains less polyunsaturated fatty acids than pork fat. The bacterial lipase LG-1000 was also efficient in reducing average fat particle size, but high doses (> 1000 mg/l) were required to obtain a significant reduction after 4 h of pretreatment. SCOD was not increased by pretreatment with LG-1000. No particle size reduction or changes in SCOD were noted after 4 h of pretreatment with the plant lipase EcoSystem Plus. It was concluded that PL-250 was the best pretreatment to hydrolyse fat particles in SHW. However, its impact on the efficiency of a downstream anaerobic digestion process remains to be tested.

Heterogenous and homogenous catalytic oxidation by supported gamma-FeOOH in a fluidized-bed reactor: kinetic approach

Oxidation of benzoic acid (BA) by H2O2 was performed with a novel supported gamma-FeOOH catalyst in a circulating fluidized-bed reactor (CFBR). This study focused mainly on determining the proportions of homogeneous catalysis and heterogeneous catalysis in this CFBR. Also studied herein was how pH, H2O2 concentration, and BA concentration affect the oxidation of BA. Experimental results indicate that the decomposition rate of H2O2 was proportional to its concentration and that the oxidation rate of BA depended on both H2O2 and BA concentrations. The change in the rate constant of heterogeneous catalysis by pH was described in terms of ionization fractions of surface hydroxyl group. From the mathematical deduction, we can infer thatthe reaction rate associated with ...Fe(III)OH2+ is markedly higher than that with ...Fe(III)OH. Conclusively, although heterogeneous catalysis contributes primarily to the oxidation of BA at pH 4.4-7.0, the homogeneous catalysis is of increasing importance below pH 4.4 because of the reductive dissolution of gamma-FeOOH.

Treatment of progressive hepatitis C recurrence after liver transplantation with combination interferon plus ribavirin

Hepatitis C virus (HCV) recurrence after orthotopic liver transplantation (OLT) is common, although the majority of cases are mild. A subset of transplant recipients develops progressive allograft injury, including cirrhosis and allograft failure. Minimal data are available on the safety and efficacy of antiviral treatment in this group of patients. The aim of this study is to review our experience in the treatment of moderate to severe HCV recurrence with combination interferon-alpha2b and ribavirin (IFN/RIB). Between October 1993 and October 1999, a total of 197 patients underwent OLT for HCV-related liver failure. This study describes 12 transplant recipients with moderate to severe recurrence treated with IFN/RIB. All patients met at least 1 of the following inclusion criteria: (1) moderate to severe inflammation (grade III to IV) on allograft biopsy, (2) bridging fibrosis on allograft biopsy, or (3) severe cholestasis attributable solely to HCV recurrence. Two patients had undergone re-OLT for allograft cirrhosis secondary to HCV recurrence and now had evidence of progressive HCV in their second allografts. Appropriate dose reductions of both IFN and RIB, as well as initiation of granulocyte colony-stimulating factor (G-CSF), for marked leukopenia were recorded. IFN/RIB therapy was started 60 to 647 days post-OLT, and duration of therapy ranged from 39 to 515 days. Seven patients were administered G-CSF to successfully treat leukopenia. Six of the 12 patients (50%) became HCV RNA negative by polymerase chain reaction. One of these 6 patients (no. 1) was HCV RNA negative at 6 months but chose to discontinue therapy because of intolerable side effects, experienced a relapse, and was HCV RNA positive at 12 months. Two of the remaining 5 patients were HCV RNA negative at 2 and 9 months off therapy. For the entire group, there was a statistically significant decrease in serum biochemical indices assessed at initiation of therapy and 1, 3, and 6 months into therapy. Most patients required dose reductions of both IFN and RIB. Five patients died; 3 patients died of liver-related complications that included severe intrahepatic biliary cholestasis, severe HCV recurrence, and chronic rejection with profound cholestasis. In the subset of HCV-positive liver transplant recipients with moderate to severe recurrence, combination IFN/RIB therapy resulted in complete virological response (serum RNA negative) in 6 of 12 patients ( approximately 50%). However, only 1 of 12 patients (8.3%) had sustained virological clearance after cessation of IFN/RIB therapy. Dose reductions of both IFN and RIB were required in most patients. The use of G-CSF (sometimes preemptively) allowed correction of leukopenia and full-dose antiviral therapy. Multicenter trials using combination therapy to identify factors predictive of response are needed in the subset of patients with progressive allograft injury.

A deletion mutation in region V of the cytomegalovirus DNA polymerase sequence confers multidrug resistance

A patient with AIDS and cytomegalovirus (CMV) retinitis received ganciclovir and foscarnet for 20 and 5 months, respectively, with evidence of periodic disease progression. After this therapy, a CMV isolate from the patient was resistant to ganciclovir, foscarnet, and cidofovir. Sequence analysis showed a known ganciclovir resistance mutation in the viral UL97 phosphotransferase (L595F) and a new mutation in conserved region V of the DNA polymerase gene (pol) sequence (codons 981-982 deleted). The pol mutation was transferred to a laboratory CMV strain (Towne) by homologous recombination and selection with either ganciclovir or foscarnet. Recombinant viruses containing this deletion showed a 6-8-fold increased ganciclovir resistance and a 3-5-fold increased resistance to both foscarnet and cidofovir, compared with the wild-type CMV. A single mutation in region V of CMV pol can, therefore, confer multiple drug resistance in a clinical isolate.

Preferential accessibility of the yeast his3 promoter is determined by a general property of the DNA sequence, not by specific elements

Yeast promoter regions are often more accessible to nuclear proteins than are nonpromoter regions. As assayed by HinfI endonuclease cleavage in living yeast cells, HinfI sites located in the promoters of all seven genes tested were 5- to 20-fold more accessible than sites in adjacent nonpromoter regions. HinfI hypersensitivity within the his3 promoter region is locally determined, since it was observed when this region was translocated to the middle of the ade2 structural gene. Detailed analysis of the his3 promoter indicated that preferential accessibility is not determined by specific elements such as the Gcn4 binding site, poly(dA-dT) sequences, TATA elements, or initiator elements or by transcriptional activity. However, progressive deletion of the promoter region in either direction resulted in a progressive loss of HinfI accessibility. Preferential accessibility is independent of the Swi-Snf chromatin remodeling complex, Gcn5 histone acetylase complexes Ada and SAGA, and Rad6, which ubiquitinates histone H2B. These results suggest that preferential accessibility of the his3 (and presumably other) promoter regions is determined by a general property of the DNA sequence (e.g., base composition or a related feature) rather than by defined sequence elements. The organization of the compact yeast genome into inherently distinct promoter and nonpromoter regions may ensure that transcription factors bind preferentially to appropriate sites in promoters rather than to the excess of irrelevant but equally high-affinity sites in nonpromoter regions.

Detection of unsuspected colonic abnormalities using the pneumocolon technique during small bowel meal examination

AIMS

The pneumocolon technique in small bowel meal examination is used to obtain double-contrast views of the distal ileum. The purpose of this study was to determine the proportion of cases in which an overhead pneumocolon radiograph demonstrated clinically relevant findings in the colon.

METHODS

The overhead pneumocolon radiographs in 151 patients who underwent small bowel meals were evaluated retrospectively. A chart review was performed on those patients with positive colonic findings to determine if the suspected abnormalities affected patient management.

RESULTS

Colonic abnormalities were identified in 34 of the 151 patients. One patient had a previously undiagnosed ascending colonic cancer; 17 had evidence of acute or chronic colitis; 13 had diverticulosis; one had a caecal polyp; one had an ileosigmoid fistula; one had a filling defect in the ascending colon. In 25 cases the colonic abnormality was visible only on the pneumocolon radiograph and not on the preceding single-contrast images. Management was altered by the colonic findings in seven cases. False-positive findings occurred in two cases.

CONCLUSIONS

A routine overhead radiograph following use of the pneumocolon technique is a useful adjunct to small bowel meal examination as it can yield unsuspected and clinically significant colonic findings.Chou, S. (2000). Clinical Radiology55, 459-464.

Efficacy and safety of patient-controlled analgesia for morbidly obese patients following gastric bypass surgery

BACKGROUND

Adequate postoperative pain control is important to reduce potential cardiopulmonary complications. It is often difficult to determine dosages of narcotics for morbidly obese patients following Roux-en-Y gastric bypass (RYGBP) due to respiratory depression. Individualization of analgesic therapy, patient-controlled analgesia (PCA), can provide optimal dosage for pain control and minimize the side-effects.

METHOD

25 morbidly obese patients who received PCA with morphine sulfate following RYGBP. PCA settings we re as follows: morphine, 20 microg/kg of ideal body weight, 10-minute lock out interval and 80 % of a calculated amount for a 4-hour limit. W e measured arterial blood gas, heart rate, mean arterial pressure, arterial oxygen saturation, respiratory rate, opioid amount, patient satisfaction, visual analog pain scale (VAS), and the incidence of nausea, vomiting, pruritus and sedation.

RESULTS

Average morphine usage was 44.2+/-28.7 mg during the day of surgery (DOS); 49.1+/-27.4 mg during POD (postoperative day) #1; and 36.6+/-22.8 mg during POD#2 (p < 0.01). 24 patients were satisfied with their pain control on POD#1. VAS was 5.4+/-2.1 on the day of surgery, but remained below 4 thereafter. Arterial oxygen saturation and vital signs were maintained without significant changes. 5 patients experienced mild sedation on the day of surgery and 3 patients experienced mild sedation on POD#1. 1 patient experienced nausea and vomiting and 4 patients had pruritus; however, none required treatment.

CONCLUSION

PCA is safe and effective for morbidly obese patients following RYGBP.

A standardized plaque reduction assay for determination of drug susceptibilities of cytomegalovirus clinical isolates

Twelve laboratories collaborated in formulating and testing a standardized plaque reduction assay for cytomegalovirus (CMV) cell-associated clinical isolates. Four characterized and plaque-purified CMV strains, as well as six coded clinical isolates obtained after antiviral therapy, were distributed and tested. Good agreement was obtained for four of the clinical isolates, but a broad distribution of results was obtained for two isolates. Analysis of these results indicates the problems associated with clinical isolates, including the large genetic variability and the highly cell-associated phenotype. This collaborative effort, by addressing these problems, represents a significant step toward the development of a standardized assay.

Pitfalls in the interpretation of MIBG scans in cervical neuroblastoma

Cervical neuroblastoma (CNB) is relatively rare, accounting for less than 5% of these tumors. Because it arises from the cervical sympathetic chain, complete resection will leave the child with Horner's syndrome in a high proportion of cases. Advances in technology have allowed for the development of diagnostic and imaging modalities more specific to the disease. One of these has been the advent of radiolabeled meta-iodobenzylguanidine (MIBG) to assess the primary tumor and focal metastatic involvement. This nuclide is also taken up by normal salivary-gland tissue; this may be altered, however, in the presence of sympathetic denervation. We present a case of a primary CNB associated with Horner's syndrome, which led to confusion in interpretation of the subsequent MIBG scan. We alert the reader to potential pitfalls in the use of this examination in this disease entity.

A nine-codon deletion mutation in the cytomegalovirus UL97 phosphotransferase gene confers resistance to ganciclovir

A deletion mutation (codons 595 to 603) in the cytomegalovirus (CMV) UL97 gene was recently reported after sequence analysis of leukocyte DNA from a patient receiving ganciclovir. The corresponding viral phenotype was examined by transfer of this mutation to a laboratory CMV strain (strain Towne). The recombinant virus was resistant to ganciclovir (8.4-fold increase in the 50% inhibitory concentration), was sensitive to foscarnet, and replicated normally in cell culture.

Donor polymorphism of tumor necrosis factor gene: relationship with variable severity of hepatitis C recurrence after liver transplantation

BACKGROUND

Hepatitis C-related liver failure is the leading indication for liver transplantation worldwide. Although histologic recurrence is identified in the majority of patients, the spectrum of allograft injury is wide. To date, most studies have focused on the contribution of immunosuppression and viral factors. We hypothesized that the allograft plays a significant role in determining timing and severity of hepatitis C virus (HCV) recurrence. The purpose of this analysis was to determine if genetic polymorphisms of the tumor necrosis factor (TNF) locus were associated with the highly variable severity of HCV recurrence.

METHODS

Thirty-one HCV-seropositive liver transplant recipients with long-term follow-up were studied. Genomic DNA was extracted from archived donor spleens which corresponded to each patient. We performed polymerase chain reaction amplification, followed by sequencing for two promoter TNF-alpha variants (at positions -238 and -308), and restriction fragment length analysis for four polymorphic loci within the TNF-beta gene (NcoI, TNFc, aa13, and aa26).

RESULTS

The relative prevalence of polymorphisms corresponded to distributions previously reported in normal control populations. Twenty-two of 31 (71%) patients received a donor liver homozygous for the wild type allele (TNF1) at the -308 TNF-alpha promoter region. The interval to histologic recurrence was significantly shorter and severity of HCV allograft hepatitis was significantly greater in patients with one or two TNF308.2 alleles. At last follow-up biopsy, 5 of 9 (56%) patients with a TNF308.2 donor liver had evidence of severe histological activity index as compared to 2 of 22 (9%) of patients receiving a donor liver homozygous for the TNF1 allele (P = 0.01). There was no correlation between rejection rates and the presence of any TNF-alpha or TNF-beta alleles. TNF-beta polymorphisms within the donor liver did not correlate with severity of HCV recurrence.

CONCLUSIONS

The donor TNF-alpha promoter genotype may influence the inflammatory response to HCV reinfection of the graft and contribute to accelerated graft injury. If the association between this genetic marker (TNF308.2) and disease progression is confirmed, it could improve our understanding of HCV pathogenesis and influence donor selection and patient management.