Negative and positive mental health characteristics of affected family members: Findings from a cross-sectional Australian general population gambling study

Despite the impact of problem gambling on affected family members (AFMs), there are limited large-scale population level studies identifying the negative mental health (NMH) and positive mental health (PMH) characteristics of AFMs. Furthermore, no study has explored whether PMH characteristics are protective in the relationships between AFM status and NMH characteristics. This study involved secondary data analysis from the Third Social and Economic Impact Study of Gambling in Tasmania. Using a subsample of 1,869 adults (48.30 % male; meanage = 48.48; 4.67 % AFMs), this study aimed to explore whether: (1) AFM status is associated with NMH (depression, anxiety, panic, post-traumatic stress disorder, social anxiety, binge drinking, tobacco use, and drug use symptoms) and PMH (quality of life [QOL], personal growth/autonomy, interpersonal/social skills, coping skills) characteristics after separately controlling for sociodemographic, problem gambling severity, and other NMH characteristics; (2) PMH characteristics moderate (buffer) the relationships between AFM status and NMH characteristics; and (3) gender influences these relationships. AFM status, defined as exposure to family member gambling problems, significantly positively predicted NMH characteristics (depression, anxiety, panic, PTSD, and tobacco use symptoms) and negatively predicted QOL (physical, social) and planning coping. The strength of these relationships generally attenuated after controlling for various covariates. Gender did not moderate these relationships. Religious coping exacerbated the relationship between AFM status and panic disorder symptoms. These findings can inform the development of intervention initiatives for family members exposed to gambling problems. Future population-representative research is required using a range of affected other types, longitudinal study designs, and more comprehensive measures.

Correlated population genetic structure in a three-tiered host-parasite system. The potential for coevolution and adaptive divergence

Three subspecies of Northern Bahamian Rock Iguanas, Cyclura cychlura, are currently recognized: C. c. cychlura, restricted to Andros Island, and C. c. figginsi and C. c. inornata, native to the Exuma Island chain. Populations on Andros are genetically distinct from Exuma Island populations, yet genetic divergence among populations in the Exumas is inconsistent with the two currently recognized subspecies from those islands. The potential consequences of this discrepancy might include the recognition of a single subspecies throughout the Exumas rather than two. That inference also ignores evidence that populations of C. cychlura are potentially adaptively divergent. We compared patterns of population relatedness in a three-tiered host-parasite system: C. cychlura iguanas, their ticks (genus Amblyomma, preferentially parasitizing these reptiles), and Rickettsia spp. endosymbionts (within tick ectoparasites). Our results indicate that while C. c. cychlura on Andros is consistently supported as a separate clade, patterns of relatedness among populations of C. c. figginsi and C. c. inornata within the Exuma Island chain are more complex. The distribution of the hosts, different tick species, and Rickettsia spp., supports the evolutionary independence of C. c. inornata. Further, these patterns are also consistent with two independent evolutionarily significant units within C. c. figginsi. Our findings suggest coevolutionary relationships between the reptile hosts, their ectoparasites, and rickettsial organisms, suggesting local adaptation. This work also speaks to the limitations of using neutral molecular markers from a single focal taxon as the sole currency for recognizing evolutionary novelty in populations of endangered species.

The Relative and Interactive Effects of Actual and Perceived Gambling Exposure on Gambling Behaviour

Actual and perceptual measures of gambling exposure are important predictors of problem gambling. This study used Zero-Inflated Poisson regression analyses to assess the relative and interactive effects of actual and perceived exposure on problem gambling risk and severity. Data from the 2008 and 2009 Social and Economic Impacts of Gambling in Alberta surveys indicated actual exposure was significantly associated with problem gambling risk while perceived exposure was significantly associated with problem gambling severity. These associations differ for gamblers from emerging and mature areas. Further, actual and perceived exposure had significant interaction effects on problem gambling severity but not on risk. Implications from these findings suggest that the prevalence of problem gambling could be reduced by restrictions on gambling opportunities.

"It Runs in Your Blood": Reflections from Treatment Seeking Gamblers on Their Family History of Gambling

There are considerable gaps in our understanding of the familial transmission of gambling problems. This convergent mixed-methods study aimed to explore the: (1) sources of heterogeneity in the familial (paternal, maternal, and sibling) transmission of gambling problems; (2) degree to which family-of-origin characteristics are associated with family-of-origin problem gambling; and (3) beliefs of gamblers about the nature of the familial transmission of problem gambling. The sample consisted of 97 treatment-seeking gamblers in Australia. One-quarter (25.5%) of participants reported that at least one family member (16.5% father, 7.5% mother, 7.6% siblings) living with them when they were growing up had a gambling problem. Most participants reported that family members with a positive history of problem gambling were biological relatives, lived with them full-time, and experienced long-term difficulties with gambling. Participants with a family history of problem gambling were young (less than 12 years of age) at the onset of parental, but not sibling, problem gambling, were women, and reported difficulties with the same gambling activity as their family member. Participants raised in families with problem gambling were more likely to report parental separation (risk ratio [RR] = 2.32) and divorce (RR = 2.83), and extreme family financial hardship (RR = 1.80), as well as low levels of paternal authoritative parenting than participants raised in non-problem gambling families. Qualitatively, both social learning and genetics were perceived to play a central role in the familial transmission of gambling problems. These findings inform theories of the familial transmission of gambling problems and the design of targeted prevention and intervention strategies.

The complete mitochondrial genome of the critically endangered Lesser Antillean iguana (Iguana delicatissima; Squamata: Iguanidae)

The Lesser Antillean iguana, Iguana delicatissima Laurenti 1768, is one of the most endangered vertebrate taxa in the West Indies. This species faces significant threats, including introgressive hybridization with the introduced congener Iguana iguana. We deploy a combination of off-target sequence capture obtained from Illumina^® reads and targeted Sanger reads to assemble the mitochondrial genome of I. delicatissima. The mitogenome is 16,616 bp in length and is comprised of 13 protein-coding genes, two ribosomal subunits (rRNAs), 22 transfer RNAs, and a control region. Gene order is identical to that of congener I. iguana and other closely related taxa, absent of any tandem repeat regions. We show the phylogenetic utility of the mitogenome with a maximum-likelihood analysis, which yields a topology concordant with previous studies of iguanine taxa. We are hopeful that this genomic resource will be useful in further informing applied conservation and management for this critically endangered species.

Rabies: a medical perspective

Rabies is an acute neurological infection of humans and animals, caused by rabies virus and usually transmitted by animal bites. After an incubation period usually lasting weeks or longer, a variety of prodromal symptoms may occur. Encephalitic rabies (80% of cases) is associated with episodes of generalised arousal or hyperexcitability and hydrophobia, in which spasms involve the contraction of inspiratory muscles with swallowing. Paralytic rabies (in 20% of cases) is characterised by progressive lower motor neuron weakness. Laboratory investigations are important for confirming an ante mortem diagnosis of rabies. Cardiopulmonary and many other complications, including multiple organ failure, are common in aggressively managed rabies patients in critical care units. No effective therapy is available for rabies and survivors are uncommon. In contrast, preventative measures for rabies are highly effective after recognised exposures.

Problem Gambling Family Impacts: Development of the Problem Gambling Family Impact Scale

Although family members of problem gamblers frequently present to treatment services, problem gambling family impacts are under-researched. The most commonly endorsed items on a new measure of gambling-related family impacts [Problem Gambling Family Impact Measure (PG-FIM: Problem Gambler version)] by 212 treatment-seeking problem gamblers included trust (62.5 %), anger (61.8 %), depression or sadness (58.7 %), anxiety (57.7 %), distress due to gambling-related absences (56.1 %), reduced quality time (52.4 %), and communication breakdowns (52.4 %). The PG-FIM (Problem Gambler version) was comprised of three factors: (1) financial impacts, (2) increased responsibility impacts, and (3) psychosocial impacts with good psychometric properties. Younger, more impulsive, non-electronic gaming machine (EGM) gamblers who had more severe gambling problems reported more financial impacts; non-EGM gamblers with poorer general health reported more increased responsibility impacts; and more impulsive non-EGM gamblers with more psychological distress and higher gambling severity reported more psychosocial impacts. The findings have implications for the development of interventions for the family members of problem gamblers.

The Prevalence of Comorbid Personality Disorders in Treatment-Seeking Problem Gamblers: A Systematic Review and Meta-Analysis

The aim of this study was to systematically review and meta-analyze the prevalence of comorbid personality disorders among treatment-seeking problem gamblers. Almost one half (47.9%) of problem gamblers displayed comorbid personality disorders. They were most likely to display Cluster B disorders (17.6%), with smaller proportions reporting Cluster C disorders (12.6%) and Cluster A disorders (6.1%). The most prevalent personality disorders were narcissistic (16.6%), antisocial (14.0%), avoidant (13.4%), obsessive-compulsive (13.4%), and borderline (13.1%) personality disorders. Sensitivity analyses suggested that these prevalence estimates were robust to the inclusion of clinical trials and self-selected samples. Although there was significant variability in reported rates, subgroup analyses revealed no significant differences in estimates of antisocial personality disorder according to problem gambling severity, measure of comorbidity employed, and study jurisdiction. The findings highlight the need for gambling treatment services to conduct routine screening and assessment of co-occurring personality disorders and to provide treatment approaches that adequately address these comorbid conditions.

Problem gambling and family violence: prevalence and patterns in treatment-seekers

The primary aim of this study was to explore the prevalence and patterns of family violence in treatment-seeking problem gamblers. Secondary aims were to identify the prevalence of problem gambling in a family violence victimisation treatment sample and to explore the relationship between problem gambling and family violence in other treatment-seeking samples. Clients from 15 Australian treatment services were systematically screened for problem gambling using the Brief Bio-Social Gambling Screen and for family violence using single victimisation and perpetration items adapted from the Hurt-Insulted-Threatened-Screamed (HITS): gambling services (n=463), family violence services (n=95), alcohol and drug services (n=47), mental health services (n=51), and financial counselling services (n=48). The prevalence of family violence in the gambling sample was 33.9% (11.0% victimisation only, 6.9% perpetration only, and 16.0% both victimisation and perpetration). Female gamblers were significantly more likely to report victimisation only (16.5% cf. 7.8%) and both victimisation and perpetration (21.2% cf. 13.0%) than male gamblers. There were no other demographic differences in family violence prevalence estimates. Gamblers most commonly endorsed their parents as both the perpetrators and victims of family violence, followed by current and former partners. The prevalence of problem gambling in the family violence sample was 2.2%. The alcohol and drug (84.0%) and mental health (61.6%) samples reported significantly higher rates of any family violence than the gambling sample, while the financial counselling sample (10.6%) reported significantly higher rates of problem gambling than the family violence sample. The findings of this study support substantial comorbidity between problem gambling and family violence, although this may be accounted for by a high comorbidity with alcohol and drug use problems and other psychiatric disorders. They highlight the need for routine screening, assessment and management of problem gambling and family violence in a range of services.

Great skua (Stercorarius skua) movements at sea in relation to marine renewable energy developments

Marine renewable energy developments (MREDs) are an increasing feature of the marine environment. Owing to the relatively small number of existing developments and the early stage of their associated environmental monitoring programmes, the effects of MREDs on seabirds are not fully known. Our ability to fully predict potential effects is limited by a lack of knowledge regarding movements of seabirds at sea. We used GPS tracking to improve our understanding of the movements at sea of a protected seabird species breeding in Scotland, the great skua (Stercorarius skua), to better predict how this species may be affected by MREDs. We found that the overlap of great skuas with leased and proposed MREDs was low; particularly with offshore wind sites, which are predicted to present a greater risk to great skuas than wave or tidal-stream developments. Failed breeders overlapped with larger areas of MREDs than breeding birds but the overall overlap with core areas used remained low. Overlap with wave energy development sites was greater than for offshore wind and tidal-stream sites. Comparison of 2011 data with historical data indicates that distances travelled by great skuas have likely increased over recent decades. This suggests that basing marine spatial planning decisions on short-term tracking data could be less informative than longer-term data.

Human rabies therapy: lessons learned from experimental studies in mouse models

Ketamine was one of the therapeutic agents used as a therapy for a human rabies survivor who did not receive rabies vaccine. Ketamine therapy is re-examined here in infected mouse primary neuron cultures and in adult ICR mice using the CVS strain with both intracerebral and peripheral routes of inoculation with ketamine vs. vehicle given intraperitoneally. No significant beneficial therapeutic effects of ketamine in the cultures or mouse model were observed. This team does not recommend further widespread clinical use of ketamine on human rabies patients until further experimental work demonstrates therapeutic efficacy. Because of the potential neuroprotective and anti-apoptotic properties of minocycline, minocycline therapy was assessed in infected primary neuron cultures and in neonatal ICR mice infected by peripheral inoculation with a highly attenuated rabies virus strain. No beneficial effect of minocycline was observed in the primary neuron cultures. In the mouse model, minocycline therapy aggravated the clinical neurological disease and resulted in higher mortality. An anti-apoptotic effect of minocycline was noted in the brains of infected mice, which may have very mildly increased viral spread. An anti-inflammatory effect was also noted in the brain using a CD3 T cell marker. These effects likely aggravated the disease. This team recommends that empirical therapy with minocycline be avoided in the management of rabies and viral encephalitis in humans until more information becomes available.

Rabies in Red Foxes (Vulpes vulpes) Experimentally Infected with European Bat Lyssavirus Type 1

The susceptibility of red foxes (Vulpes vulpes) to European bat lyssavirus type 1 (EBLV-1) infection was examined. Eight foxes were inoculated intramuscularly (i.m.) with 10(4.9) foci-forming units (FFU) (n = 4) and 10(5.1) FFU (n = 4) and observed for up to 90 days. All foxes showed manifestations of a neurologic disorder (e.g. seizures, myoclonus, agitation), starting as early as 5 days post-infection (p.i.). Subsequently, all animals showed improvement followed by one or more relapses. One fox was killed 3 days after it recovered, 26 days post-infection. Two other foxes were also killed 38 and 54 days post-infection after severe neurologic signs returned. All foxes developed a humoral immune response against EBLV-1 as determined in serum and brain tissues. However, no rabies virus antigen was detected in the brain, other tissues and secretions examined (e.g. salivary gland, saliva, tonsils, lungs) by using different standard diagnostic techniques [fluorescent antibody test, reverse transcription polymerase chain reaction (RT-PCR), rabies tissue culture inoculation test], with the exception of one fox in which EBLV-1 RNA was detected by RT-PCR in only the spinal cord. Brain tissues showed moderate to severe multifocal, mononuclear encephalomyelitis in the three foxes that were killed during the observation period, although no EBLV-1 virus was detectable in these tissues.

Assessing the evidence on case management

BACKGROUND

Evidence on the impact of case management is contradictory.

AIMS

To discuss two different systematic reviews (one conducted by the authors and one conducted through the Cochrane collaboration) that came to contradictory conclusions about the impact of case management in mental health services.

METHOD

We summarised the findings of the two reviews with respect to case management effectiveness, examined key methodological differences between the two approaches and discuss the impact of these on the validity of the results.

RESULTS

The differences in conclusions between the two reviews result from the differences in inclusion criteria, namely non-randomised trials, data from unpublished scales and data from variables with skewed distributions. The theoretical and empirical effects of these are discussed.

CONCLUSIONS

Systematic reviewers may face a trade-off between the application of strict criteria for the inclusion of studies and the amount of data available for analysis and hence statistical power. The available research suggests that case management is generally effective.

Experimental rabies virus infection in Artibeus jamaicensis bats with CVS-24 variants

An experimental model of rabies was established in the fruit-eating bat species Artibeus jamaicensis. The infections caused by CVS-N2c and CVS-B2c, which are both stable variants of CVS-24, were compared after inoculation of adult bats in the right masseter muscle. CVS-N2c produced neurologic signs of rabies with paresis, ataxia, and inability to fly, while CVS-B2c did not produce neurologic signs. Bats were sacrificed and the distribution of rabies virus antigen was assessed in tissue sections with immunoperoxidase staining. Both viruses spread to the brain stem and bilaterally to the trigeminal ganglia by days 2 to 3. CVS-N2c had disseminated widely in the central nervous system (CNS) by day 4 and had involved the spinal cord, thalamus, cerebellum, and cerebral cortex. CVS-B2c had infected neurons in the spinal cord on day 5 and in the cerebellum, thalamus, and cerebral cortex on day 6. Infected pyramidal neurons of the hippocampus were observed on day 5 in CVS-N2c infection, but infected neurons were never noted in the hippocampus in CVS-B2c infection. CVS-N2c infected many more neurons and more prominently involved neuronal processes than CVS-B2c. CVS-N2c spread more efficiently in the CNS than CVS-B2c. Morphologic changes of apoptosis or biochemical evidence of DNA fragmentation were not observed in neurons with either virus after this route of inoculation. The different neurovirulent properties of these CVS variants in this model were not related to their in vivo ability to induce apoptosis.

Quantitative study of the infection in brain neurons in human rabies

Rabies virus is a highly neuronotropic virus that causes encephalomyelitis. Rabies virus infection was studied in neurons in the brain of an 8-year-old girl that died of rabies in Mexico. The extent of the neuronal infection was evaluated quantitatively in neuronal cell types of the brain using histologic staining for Negri bodies and immunoperoxidase staining for rabies virus antigen in the same neurons. Quantitative image analysis was used to compare the amount of infection in five different neuronal cell types, which was expressed as a percentage of neuronal area. Purkinje cells and periaqueductal gray neurons showed the largest percentage area for both Negri bodies and signal for rabies virus antigen. In general, there was a good linear relationship between the area of Negri bodies and the area of signal for rabies virus antigen. Many neurons with rabies virus antigen did not have Negri bodies, however, and some neurons with large antigen signals, especially Purkinje cells and periaqueductal gray neurons, lacked Negri bodies. Formation of Negri bodies is likely influenced by factors that vary in different neuronal cell types.

A sperm ion channel required for sperm motility and male fertility

Calcium and cyclic nucleotides have crucial roles in mammalian fertilization, but the molecules comprising the Ca2+-permeation pathway in sperm motility are poorly understood. Here we describe a putative sperm cation channel, CatSper, whose amino-acid sequence most closely resembles a single, six-transmembrane-spanning repeat of the voltage-dependent Ca2+-channel four-repeat structure. CatSper is located specifically in the principal piece of the sperm tail. Targeted disruption of the gene results in male sterility in otherwise normal mice. Sperm motility is decreased markedly in CatSper-/- mice, and CatSper-/- sperm are unable to fertilize intact eggs. In addition, the cyclic-AMP-induced Ca2+ influx is abolished in the sperm of mutant mice. CatSper is thus vital to cAMP-mediated Ca2+ influx in sperm, sperm motility and fertilization. CatSper represents an excellent target for non-hormonal contraceptives for both men and women.

Determinants of anti-psychotic medication compliance in a multicultural population

The efficacy of medication in controlling or ameliorating symptoms of psychotic conditions is well established in clinical trials, but medication effectiveness in mental health services is considerably affected by the extent to which clients actually comply to their prescribed medication. This study aimed to assess the relative influence of demographic, medication, social support and relationship variables on perceived compliance with medication in a sample of clients with serious mental illness from diverse ethnic backgrounds. It also aimed to explore whether compliance differed by matching clients with a case manager from the same ethno-linguistic background. Data on medication compliance, administration route, medication dose, sex, age, impairment of thought processes, mood abnormality, ability to manage money, acceptance of illness (insight), social network size, alcohol and drug use, impulse control, and cooperation with staff were provided by case managers for 168 clients from diverse ethnic backgrounds. Multiple regression analysis was used to examine the predictors of medication compliance. The main predictors of greater compliance were greater general cooperation with staff, better insight, and matching clients with a case manager from the same ethnic background.

Entraining the natural frequencies of running and breathing in guinea fowl (Numida meleagris)

Lung ventilation of tetrapods that synchronize their locomotory and ventilatory cycles during exercise could be economized if the resonant frequency of the respiratory system matched the animal's preferred step frequency. To test whether animals utilize this strategy, the input impedance of the respiratory system of five anesthetized, supine guinea fowl (Numida meleagris) was measured using a forced oscillation technique. The resonant frequency of the respiratory system was 7.12+/−0.27 Hz (N=5, mean +/− S.E.M.). No statistically significant difference was found between the resonant frequency of the respiratory system and the panting frequency used by guinea fowl at rest (6.67+/−0.16 Hz, N=11) or during treadmill locomotion (6.71+/−0.12 Hz, N=8) or to their preferred step frequency (6.73+/−0.09 Hz, N=7) (means +/− S.E.M.). These observations suggest (i) that, at rest and during exercise, panting guinea fowl maximize flow while expending minimal mechanical effort, and (ii) that natural selection has tuned the natural frequencies of the respiratory and locomotor systems to similar frequencies.

Regional access to acute ischemic stroke intervention

BACKGROUND AND PURPOSE

Benefit-risk ratios from recombinant tissue plasminogen activator (rtPA) therapy for acute ischemic stroke demonstrate lack of efficacy if intravenous administration is commenced beyond 3 hours of symptom onset. We undertook to enhance therapeutic effectiveness by ensuring equitable access to rtPA for patients affected by acute ischemic stroke within a 20 000 km(2) population referral base served by a tertiary facility.

METHODS

Representatives of all provider groups involved in emergency medical services developed a Regional Acute Stroke Protocol (RASP), a coordinated regional system response by dispatch personnel, paramedics, physicians, community service providers, emergency and inpatient staff in community hospitals, and the tertiary facility acute stroke team.

RESULTS

As of July 26, 1999, all ambulance services in Southeastern Ontario began bypassing the closest hospital to deliver patients meeting the criteria for the RASP to the Kingston General Hospital. At 12 months, approximately 403 ischemic strokes have occurred in the region, the RASP has been activated 191 times, and 42 patients have received rtPA.

CONCLUSIONS

We conclude that (1) acute stroke patients in Southeastern Ontario have improved access to interventions for stroke care; (2) geography of the region is not a barrier to access to interventions for patients with acute stroke; and (3) acute ischemic stroke patients treated with rtPA account for 5% of all acute strokes and 10% of all ischemic strokes in this region.

Airway resistance and tissue elastance from input or transfer impedance in bronchoconstricted monkeys

Ascaris suum (AS) challenge in nonhuman primates is used as an animal model of human asthma. The primary goal of this study was to determine whether the airways and respiratory tissues in monkeys that are bronchoconstricted by AS inhalation behave similarly to those in asthmatic humans. Airway resistance (Raw) and tissue elastance (Eti) were estimated from respiratory system input (Zin) or transfer (Ztr) impedance. Zin (0.4-20 Hz) and Ztr (2-128 Hz) were measured in anesthetized cynomolgus monkeys (n = 10) under baseline (BL) and post-AS challenge conditions. Our results indicate that AS challenge in monkeys produces 1) predominantly an increase in Raw and not tissue resistance, 2) airway wall shunting at higher AS doses, and 3) heterogeneous airway constriction resulting in a decrease of lung parenchyma effective compliance. We investigated whether the airway and tissue properties estimated from Zin and Ztr were similar and found that Raw estimated from Zin and Ztr were correlated [r(2) = 0.76], not significantly different at BL (13.6 +/- 1.4 and 13.1 +/- 0.9 cmH(2)O. l(-1). s(-1), respectively), but significantly different post-AS (20.5 +/- 4.5 cmH(2)O. l(-1). s(-1) and 18.5 +/- 5.2 cmH(2)O. l(-1). s(-1)). There was no correlation between Eti estimated from Zin and Ztr. The changes in lung mechanical properties in AS-bronchoconstricted monkeys are similar to those recently reported in human asthma, confirming that this is a reasonable model of human asthma.

Discharge planning for complex paediatric cases

The aim of this study was to identify the functions performed by social workers specifically engaged in paediatric discharge planning by undertaking a detailed analysis of discharge planning practice in forty cases referred to a specialist discharge planning team, at the Royal Children's Hospital, Melborne. A second aim was to identify the characteristics that distinguished complex cases from more routine cases. Discharge planning activity focused on the family, community and the organisation, with most cases requiring activity in all three areas. More complex cases were characterised by amount of social work time spent on the case, length of stay and number of discharge planner functions performed, but not number of prior admissions.

Rabies

Rabies is an important disease in wildlife in the United States and Canada, and dog rabies is still a major public health problem in many developing countries of the world. Rabies virus is transmitted in saliva by animal bites. Bats transmitted most recent cases of human rabies in the United States, often without known exposures. There have been recent developments in our understanding of rabies pathogenesis. Characteristic clinical features should raise the possibility of a diagnosis of rabies and initiation of appropriate diagnostic tests. Therapy of human rabies has been futile except in four patients who were immunized with rabies vaccine prior to the onset of their disease. Rabies can be prevented after an exposure in unimmunized patients with local wound cleansing and administration of rabies vaccine and human rabies immune globulin.

Receptor-mediated internalization of somatostatin in rat cortical and hippocampal neurons

Binding of neuropeptides to their receptors usually results in internalization of receptor-ligand complexes. This process serves a crucial role in receptor downregulation, resensitization, and transmembrane signaling. It has mainly been investigated in cells ectopically expressing recombinant receptors. In the present study, we investigated whether rat central neurons and astrocytes naturally expressing somatostatin (SRIF) receptors internalized this neuropeptide. We demonstrated that 29% of cortical and 45% of hippocampal neurons in culture expressed the SRIF receptor sst(2A) and that 40-50% of the neurons internalized fluorescent SRIF. Similarly, an important proportion of astrocytes expressed sst(2A) (up to 60% in cortical cultures) and internalized fluo-SRIF. Competition experiments using the sst(2)/sst(5)-preferring agonist SMS 201-995 (octreotide) showed that a subpopulation of neurons internalized fluo-SRIF via sst(2) and/or sst(5) receptors, but that others also did so via other subtypes. Fluo-SRIF labeling was barely competed for by the sst(1)-selective agonist CH-275, indicating that sst(1) was unlikely to be mediating SRIF internalization in hippocampal and cortical neurons. Given the paucity of sst(5) receptors in cerebral cortex and hippocampus and the poor yield of sst(4) internalization in transfected cells, we conclude that sst(2) and sst(3) subtypes are the most likely to be responsible for SRIF internalization in our culture systems.

Infection of Bergmann glia in the cerebellum of a skunk experimentally infected with street rabies virus

Rabies virus is a highly neuronotropic virus and glial cell infection is not prominent in the central nervous system (CNS). Paraffin-embedded tissues from the cerebella of skunks experimentally infected with either a skunk salivary gland isolate of street rabies virus or the challenge virus standard (CVS) strain of fixed rabies virus were examined with immunoperoxidase staining for rabies virus antigen by using an anti-rabies virus nucleocapsid protein monoclonal antibody. A skunk infected with street rabies virus showed prominent infection of Bergmann glia. Although infected Purkinje cells were observed, they usually demonstrated a relatively small amount of antigen in their perikarya. A CVS-infected skunk showed many intensely labeled Purkinje cells and a relatively small number of infected Bergmann glia. These findings indicate that although rabies virus is a highly neuronotropic virus, street rabies virus strains do not always demonstrate strict neuronotropism in the central nervous system.

Ectopic expression of a tomato 9-cis-epoxycarotenoid dioxygenase gene causes over-production of abscisic acid

The tomato mutant notabilis has a wilty phenotype as a result of abscisic acid (ABA) deficiency. The wild-type allele of notabilis, LeNCED1, encodes a putative 9-cis-epoxycarotenoid dioxygenase (NCED) with a potential regulatory role in ABA biosynthesis. We have created transgenic tobacco plants in which expression of the LeNCED1 coding region is under tetracycline-inducible control. When leaf explants from these plants were treated with tetracycline, NCED mRNA was induced and bulk leaf ABA content increased by up to 10-fold. Transgenic tomato plants were also produced containing the LeNCED1 coding region under the control of one of two strong constitutive promoters, either the doubly enhanced CaMV 35S promoter or the chimaeric 'Super-Promoter'. Many of these plants were wilty, suggesting co-suppression of endogenous gene activity; however three transformants displayed a common, heritable phenotype that could be due to enhanced ABA biosynthesis, showing increased guttation and seed dormancy. Progeny from two of these transformants were further characterized, and it was shown that they also exhibited reduced stomatal conductance, increased NCED mRNA and elevated seed ABA content. Progeny of one transformant had significantly higher bulk leaf ABA content compared to the wild type. The increased seed dormancy was reversed by addition of the carotenoid biosynthesis inhibitor norflurazon. These data provide strong evidence that NCED is indeed a key regulatory enzyme in ABA biosynthesis in leaves, and demonstrate for the first time that plant ABA content can be increased through manipulating NCED.

Rabies

Human rabies is fatal except in the small number of patients who received rabies immunization before the onset of clinical rabies. Therapy has been futile in all other cases once rabies has developed. Rabies is always preventable after an exposure if current recommendations are followed. After a potential rabies exposure, details about the contact, the animal, and the local epidemiologic situation are important in making a decision whether to initiate postexposure prophylaxis (PEP). Rabies PEP includes thorough local wound cleansing and both active and passive immunization. Five doses of rabies vaccine should be administered intramuscularly in the deltoid muscle on days 0, 3, 7, 14, and 28 in individuals previously unimmunized against rabies virus. Human rabies immune globulin (20 IU/kg) should be given on day 0 with administration into and around the wounds; the remaining volume is given intramuscularly at a site distant from the vaccine site. Certain individuals at high risk for rabies exposure are candidates for preexposure prophylaxis with three doses of rabies vaccine. Booster doses should be given as required.

Abscisic acid biosynthesis in tomato: regulation of zeaxanthin epoxidase and 9-cis-epoxycarotenoid dioxygenase mRNAs by light/dark cycles, water stress and abscisic acid

Two genes encoding enzymes in the abscisic acid (ABA) biosynthesis pathway, zeaxanthin epoxidase (ZEP) and 9-cis-epoxycarotenoid dioxygenase (NCED), have previously been cloned by transposon tagging in Nicotiana plumbaginifolia and maize respectively. We demonstrate that antisense down-regulation of the tomato gene LeZEP1 causes accumulation of zeaxanthin in leaves, suggesting that this gene also encodes ZEP. LeNCED1 is known to encode NCED from characterization of a null mutation (notabilis) in tomato. We have used LeZEP1 and LeNCED1 as probes to study gene expression in leaves and roots of whole plants given drought treatments, during light/dark cycles, and during dehydration of detached leaves. During drought stress, NCED mRNA increased in both leaves and roots, whereas ZEP mRNA increased in roots but not leaves. When detached leaves were dehydrated, NCED mRNA responded rapidly to small reductions in water content. Using a detached leaf system with ABA-deficient mutants and ABA feeding, we investigated the possibility that NCED mRNA is regulated by the end product of the pathway, ABA, but found no evidence that this is the case. We also describe strong diurnal expression patterns for both ZEP and NCED, with the two genes displaying distinctly different patterns. ZEP mRNA oscillated with a phase very similar to light-harvesting complex II (LHCII) mRNA, and oscillations continued in a 48 h dark period. NCED mRNA oscillated with a different phase and remained low during a 48 h dark period. Implications for regulation of water stress-induced ABA biosynthesis are discussed.

Intracellular dynamics of sst5 receptors in transfected COS-7 cells: maintenance of cell surface receptors during ligand-induced endocytosis

Internalization of G protein-coupled receptors is crucial for resensitization of phosphorylation-desensitized receptors, but also for their long term desensitization through sequestration. To elucidate the mechanisms regulating cell surface availability of the somatostatin (SRIF) receptor subtype sst5, we characterized its internalization properties in transfected COS-7 cells using biochemical, confocal microscopic, and electron microscopic techniques. Our results demonstrated rapid and efficient sequestration of specifically bound [125I]Tyr0-D-Trp8-SRIF (up to 45% of bound radioactivity). Combined immunocytochemical detection of sst5 and visualization of a fluorescent SRIF analog by confocal microscopy revealed that whereas the internalized ligand progressively clustered toward the cell center with time, immunoreactive receptors remained predominantly associated with the plasma membrane. The preservation of cell surface receptors was confirmed by binding experiments on whole cells revealing a lack of saturability of [125I]Tyr0-D-Trp8-SRIF binding at 37 C. Binding was rendered saturable by the drug monensin, showing that receptor recycling played a key role in the preservation of cell surface receptors. Electron microscopy demonstrated that in addition to receptor recycling, internalization of receptor-ligand complexes triggered a massive recruitment of sst5 receptor molecules from intracellular stores to the membrane. This combination of recycling and recruitment of spare receptors may protect sst5 from long term down-regulation through sequestration and, therefore, facilitate extended SRIF signaling.

Experimental rabies virus infection of p75 neurotrophin receptor-deficient mice

The low-affinity neurotrophin (NT) receptor, p75(NTR), has complex biologic functions. A recent report provided evidence that the p75(NTR) is a rabies virus receptor in cultured BSR cells. We studied the experimental infection of 6-day-old p75(NTR)-deficient mice with the challenge virus standard strain of fixed rabies virus inoculated intracerebrally. The mice developed a fatal encephalitis. There were morphologic changes of apoptotic cell death involving neurons in widespread areas of the brain, which were associated with in situ evidence of oligonucleosomal DNA fragmentation. The findings were very similar to those that we previously reported in wild-type ICR mice of the same age. If the p75(NTR) is an important receptor of rabies virus in animal hosts, then a greater effect on the clinical and pathologic features of rabies virus-infected p75(NTR)-deficient mice would have been expected.

Basis of rabies virus neurovirulence in mice: expression of major histocompatibility complex class I and class II mRNAs

Expression of major histocompatibility complex (MHC) molecules on cells of the central nervous system (CNS) plays an important role in the pathogenesis of acute viral encephalitis. We have compared the induction of MHC class I and II mRNA transcripts in mice upon infection with the virulent challenge virus standard (CVS) strain of rabies virus and avirulent rabies virus variant RV194-2. Rabies virus antigen was detected with immunoperoxidase staining and 35S-labeled RNA probes were used to detect MHC class I and class II mRNA transcripts by in situ hybridization in infected brains. In CVS and RV194-2 infected animals, MHC class I mRNA expression occurred in the brain in neurons, glia, choroid plexus epithelial cells, ependymal cells, and inflammatory cells; expression was moderately higher in CVS-infected mice. In contrast, MHC class II mRNA expression was minimal in CVS-infected mice and it was markedly upregulated in CNS inflammatory cells upon RV194-2 infection. Both viruses induced an acute inflammatory reaction in the cerebrospinal fluid (CSF), which was more pronounced in CVS-infected mice. Both viruses also induced an antigen specific T and B cell response detectable in lymph nodes and spleen. These studies, which show a correlation between greater expression of MHC class II mRNA in the brain following intracerebral RV194-2 infection and protection against RV194-2 infection in the brain, suggest that recovery from avirulent rabies virus infection of neural cells involves T helper cells produced and/or retained in the brain for reasons that are not entirely clear.

Apoptosis in experimental rabies in bax-deficient mice

The challenge virus standard (CVS) of fixed rabies virus produces a fatal encephalitis in adult and suckling mice after intracerebral inoculation. The infection is associated with apoptotic cell death in brain neurons and increased immunoreactivity to the Bax protein in the hippocampus and cerebral cortex. Five- to 7-day-old bax-deficient mice and their wild-type littermates were inoculated intracerebrally with either CVS or the RV194-2 variant of rabies virus, which is avirulent in adult mice after intracerebral inoculation. The clinical disease was similar with both viruses in bax-deficient and wild-type mice with 100% mortality. CVS produced similar apoptotic changes in bax-deficient and wild-type mice, except that apoptosis was more marked in neurons of the dentate gyrus and cortical neurons in the wild-type mice. After inoculation with RV194-2, the morphologic changes of apoptosis were markedly less severe in the cerebral cortex, hippocampus, and cerebellum of the bax-deficient mice than wild-type mice. However, apoptotic changes were moderate to severe in the brain stem in both wild-type and bax-deficient mice with both viruses. Although apoptotic cell death was much less prominent in bax-deficient mice after inoculation with RV194-2, apoptosis of infected brain stem neurons occurred in this fatal infection. Although the Bax protein plays an important role in modulating rabies virus-induced apoptosis under specific experimental conditions, other modulators are also likely important.

Airway and tissue resistance in wheezy infants: effects of albuterol

We partitioned total respiratory system resistance into airway (Raw) and tissue (Rti) resistance in 16 sedated infants (age 15 to 88 wk) with a history of wheezing disorders before and after inhalation of albuterol. Using systems identification methods, airway (Raw-z) and tissue resistance (Rti-z) were extracted from measurements of respiratory system transfer impedance (Ztr[omega]) over a wide frequency range (typically, 4 < f < 140 Hz). Baseline Raw-z (80.6 +/- 31.5 cm H(2)O/L/s) was significantly (p < 0.01) reduced after albuterol inhalation (60.6 +/- 22.2 cm H(2)O/L/s) but pre- and postalbuterol Rti-z were not significantly different (2.3 +/- 1.7 and 2.7 +/- 2.4 cm H(2)O/L/s, respectively). Raw-z was compared with airway resistance measured with whole-body plethysmography (Raw-p) in 10 of the 16 infants. Raw-z and Raw-p were significantly different in baseline as well as postalbuterol conditions (86.4 +/- 36.9 versus 19.0 +/- 7.0, and 60.6 +/- 22.0 versus 22.5 +/- 14.7, respectively) and they were not correlated. There was no significant difference between Raw-p under baseline and postalbuterol conditions. We conclude that airway resistance estimated from Ztr measurements comprises the major portion of total resistance (approximately 97%) in infants with wheezing disorders in baseline as well as post-beta agonist inhalation, and it is significantly reduced by albuterol inhalation.

Subpopulations of GABAergic and non-GABAergic rat dorsal horn neurons express Ca2+-permeable AMPA receptors

Subpopulations of alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptors that are either permeable or impermeable to Ca2+ are expressed on dorsal horn neurons in culture. While both mediate synaptic transmission, the Ca2+ -permeable AMPA receptors provide a Ca2+ signal that may result in a transient change in synaptic strength [Gu, J.G., Albuquerque, C., Lee, C.J. & MacDermott, A.B. (1996) Nature, 381, 793]. To appreciate the relevance of these receptors to dorsal horn physiology, we have investigated whether they show selective expression in identified subpopulations of dorsal horn neurons. Expression of Ca2+-permeable AMPA receptors was assayed using the kainate-induced cobalt loading technique first developed by Pruss et al. [Pruss, R.M., Akeson, R.L., Racke, M.M. & Wilburn, J.L. (1991) Neuron, 7, 509]. Subpopulations of dorsal horn neurons were identified using immunocytochemistry for gamma-aminobutyric acid (GABA), glycine, substance P receptor (NK1 receptor) and the Ca2+-binding proteins, calretinin and calbindin D28K. We demonstrate that, in dorsal horn neurons in culture, kainate-induced cobalt uptake is selectively mediated by Ca2+-permeable AMPA receptors, and that a majority of GABA and NK1 receptor-expressing neurons express Ca2+-permeable AMPA receptors. GABAergic dorsal horn neurons are important in local inhibition as well as in the regulation of transmitter release from primary afferent terminals. NK1 receptor-expressing dorsal horn neurons include many of the projection neurons in the nociceptive spino-thalamic pathway. Thus, we have identified two populations of dorsal horn neurons representing important components of dorsal horn function that express Ca2+-permeable AMPA receptors. Furthermore, we show that several subpopulations of putative excitatory interneurons defined by calretinin and calbindin expression do not express Ca2+-permeable AMPA receptors.

Extraneural organ involvement in human rabies

Human rabies is a fatal encephalomyelitis. After the development of the central nervous system infection, there is centrifugal spread of the rabies virus to extraneural (systemic) organs. With histochemical staining and localization of rabies virus antigen (RVA) with immunoperoxidase staining, we have examined tissue sections of organs from 14 postmortem pediatric and adult cases of human rabies acquired in Mexico and the People's Republic of China. RVA was found in nerve plexuses in multiple organs, including the gastrointestinal tract. RVA was observed in muscle fibers of the heart, tongue, and larynx. RVA frequently was observed in the adrenal medulla with an associated inflammatory reaction. Minor salivary glands of the tongue contained RVA and major salivary glands showed RVA in plexuses, but not in either acini or ducts. Epithelial cells of the tongue and taste buds were occasionally infected. RVA was observed in hair follicles of the skin and rarely in pancreatic islets. The infection of extraneural organs was sometimes, but not always, associated with an inflammatory reaction. These findings indicate that centrifugal spread of rabies virus to extraneural organs occurs frequently in human rabies.

Clinical genetics of familial progressive supranuclear palsy

Recent studies have shown that progressive supranuclear palsy (PSP) could be inherited, but the pattern of inheritance and the spectrum of the clinical findings in relatives are unknown. We here report 12 pedigrees, confirmed by pathology in four probands, with familial PSP. Pathological diagnosis was confirmed according to recently reported internationally agreed criteria. The spectrum of the clinical phenotypes in these families was variable including 34 typical cases of PSP (12 probands plus 22 secondary cases), three patients with postural tremor, three with dementia, one with parkinsonism, two with tremor, dystonia, gaze palsy and tics, and one with gait disturbance. The presence of affected members in at least two generations in eight of the families and the absence of consanguinity suggests autosomal dominant transmission with incomplete penetrance. We conclude that hereditary PSP is more frequent than previously thought and that the scarcity of familial cases may be related to a lack of recognition of the variable phenotypic expression of the disease.

High-frequency respiratory impedance measured by forced-oscillation technique in infants

Measurements of respiratory input impedance (Zin) in infants using forced oscillations at the airway opening up to 256 Hz have been shown to include a first antiresonance (ar,1). We wondered whether features derived from high-frequency Zin change during methacholine-induced airway obstruction in infants, whether those changes could be explained by a lumped parameter model as in dogs (providing a value for respiratory resistance [Rrs]), or whether they are similar to Zin data in human adults with airway obstruction. In 13 wheezy infants (age 58 +/- 19 wk) Zin(omega) was assessed at baseline, and in nine infants after methacholine challenge, using a provocation dose defined by fall of more than 30% in VmaxFRC (rapid chest-compression technique). Following methacholine challenge, VmaxFRC decreased significantly (p < 0.0005), the frequency at which ar,1 occurred ( far,1) increased significantly (p = 0.0007), and the relative maximum in the real part at far,1 [Zinre( far,1)] increased significantly (p = 0.02), whereas Rrs did not change. We conclude that in wheezy infants ar,1 is highly sensitive to changes in lung mechanics. Although ar,1 cannot be explained by a simple lumped-parameter model, it is likely due to wave propagation phenomena, as in human adults. In either case, far,1 potentially contains information about airway wall compliance, which is important for the understanding of flow limitation in infant wheezing disorders.

High-frequency respiratory input impedance measurements in infants assessed by the high speed interrupter technique

High-frequency input impedance (Z(f)) measurements, including antiresonances, provide useful noninvasive information on airway geometry and especially airway wall mechanics in the canine and human adult respiratory system. A knowledge of airway wall mechanics would be particularly important in understanding flow limitation phenomena in infants. High-frequency Z(f) has not been measured in infants above 256 Hz, because the high impedance of the infantile respiratory system would be expected to result in low amplitudes of oscillatory flow at higher frequencies. The aim of this study was to develop a technique to measure high-frequency Z(f) in infants and to elucidate the nature of the antiresonance phenomena in the Z(f) spectrum in infants. Z(f) was measured from 32-900 Hz during rapid airflow interruption by the high-speed interrupter technique (HIT) in 18 infants (aged 24-149 weeks) with wheezing disorders. The HIT enables the excitement of higher flow amplitudes at high frequencies using a pseudostep forcing function. In all infants Z(f) showed a mean (SD) first antiresonance (far,1) of 172 (35) Hz (real part of Z(f) at far,1 (Z(f)re(far,1)): 4.9 (1.1) kPa x L(-1) x s) and in five infants a second antiresonance (far,2) of 564 (51) Hz (Z(f)re(far,2): 2.0 (0.7) kPa x L(-1) x s). The antiresonances were found to be related to wave propagation in the airways (acoustic antiresonances), because they increased by a factor of approximately 2 when He-O2 was inhaled. This implies that far,1 and its harmonics are a function of airway wall compliance. In conclusion, the first and second antiresonances may be helpful in understanding flow limitation in wheezing disorders in infants, because flow limitation is related not only to airway diameter but also to airway wall compliance.

Differences in airway wall compliance as a possible mechanism for wheezing disorders in infants

High-frequency input impedance measurements (Z(f)) provide useful noninvasive information on airway geometry and especially airway wall mechanics in the canine and human adult respiratory system. Using the high-speed interrupter technique (HIT), we have shown that it is possible to measure high-frequency Z(f) in infants up to 900 Hz, including antiresonant phenomena which are known to be related to wave propagation velocity. This implies that the first antiresonant frequency (far,1) is a function of airway wall compliance. Since, airway wall mechanics are particularly important for the flow limitation phenomena, we wondered whether we could find evidence that airway wall properties were important for the occurrence of flow limitation during incremental methacholine challenge in infants. We measured Z(f) from 32-900 Hz and maximal flow at functional residual capacity (V'maxFRC) by the rapid chest compression technique in 10 infants (aged 36-81 weeks) with wheezing disorders. far,1 increased significantly at very low doses of mch before any decline could be detected in V'maxFRC. We hypothesize that these changes in far,1 are determined by mch-induced decrease in airway wall compliance. High-speed interrupter technique in combination with rapid chest compression technique can be used to study developmental differences in airway function (particularly of airway wall properties) and their contribution to airway disease and response to bronchodilator therapy in infants.

Vocal cord paralysis and respiratory muscle weakness: an unusual presentation of chronic polyneuropathy

A case of chronic polyneuropathy that manifested with an unusual combination of vocal cord paralysis and respiratory muscle weakness is reported. In addition, results of an exercise test carried out to assess the severity and mechanisms of exertional breathlessness in this unique condition with combined obstructive and restrictive disorders are described.

Use of transfer impedance measurements for clinical assessment of lung mechanics

Respiratory transfer impedance (Ztr) measured using the forced oscillation technique requires virtually no patient cooperation and provides a noninvasive approach for acquiring data reflective of lung mechanics. Also, model analysis of Ztr provides reliable estimates of separate airway and tissue properties (1), but only if data out to 64 Hz are acquired. The current study evaluated the clinical utility of Ztr from 1-80 Hz for assessing the degree and type of impaired lung function. Spirometry and Ztr measurements were made on 37 individuals: 11 healthy subjects and 26 patients with lung disease including chronic obstructive pulmonary disease (COPD), asthma, lung cancer, and sarcoidosis. Over the entire patient group, 12 were also smokers. We first established normal ranges for several Ztr features and model estimated mechanical properties. The COPD and smokers groups showed significant differences in portions of their Ztr spectra from that of the healthy group. Key Ztr spectral features included R0, the frequency at which the real part of impedance is zero; and Re4, the real part of impedance at 4 Hz. The key model parameter was airway resistance, Raw. We found Raw, Re4, and R0 to be significantly elevated during disease (p < 0.0005) and to significantly decrease with bronchodilator therapy (p < 0.025). Moreover, we found moderate to strong correlations between R0, Raw, and Re4 versus FVC and R0 versus FEV1. After bronchodilator, changes in R0, Re4, and Raw were correlated with changes in several spirometric indices. The R0 feature has not been previously evaluated since it is typically above 32 Hz (well above 32 Hz in diseased individuals) and not encompassed in previous clinical studies.

Apoptotic cell death in experimental rabies in suckling mice

A fatal encephalomyelitis developed after intracerebral inoculation of 6-day-old ICR mice with the challenge virus standard (CVS) strain of fixed rabies virus. The brains of CVS-infected mice showed widespread morphologic changes of apoptosis, which were particularly prominent in pyramidal neurons of the hippocampus and in the cerebral cortex. Evidence of oligonucleosomal DNA fragmentation was sought in situ using the TUNEL method. TUNEL staining was observed in many neurons, and rabies virus antigen was usually demonstrated with immunoperoxidase staining in similar regions. Neurons in the dentate gyrus of the hippocampus demonstrated expression of viral antigen, apoptotic changes, and positive TUNEL staining. This region normally demonstrates little infection in CVS-infected adult mice. Double labeling of neurons with TUNEL and viral antigen indicated that infected neurons actually underwent apoptosis. Increased immunoreactivity against the Bax protein was demonstrated compared to uninfected mice. Purkinje cells expressed viral antigen, but did not show significant morphologic changes of apoptosis or TUNEL staining. In contrast, neurons in the external granular layer of the cerebellum did not express viral antigen, but demonstrated greater morphologic changes of apoptosis and positive TUNEL staining than uninfected controls. Apoptotic cell death likely plays an important role in the pathogenesis of rabies virus infection in suckling mice. There was evidence of more apoptosis in the brains of suckling mice than in those of adult mice and this finding explains the greater neurovirulence of rabies virus in younger mice. Rabies virus likely induces apoptosis in vivo by both direct and indirect mechanisms.

Determination of airway and tissue resistances after antigen and methacholine in nonhuman primates

Antigen challenge of Ascaris suum-sensitive animals has been used as a model of asthma in humans. However, no reports have separated total respiratory resistance into airway (Raw) and tissue (Rti) components. We compared input impedance (Zin) and transfer impedance (Ztr) to determine Raw and Rti in anesthetized cynomolgus monkeys under control and bronchoconstricted conditions. Zin data between 1 and 64 Hz are frequency dependent during baseline conditions, and this frequency dependence shifts in response to A. suum or methacholine. Thus it cannot be modeled with the DuBois model, and estimates of Raw and Rti cannot be determined. With Ztr, baseline data were much less variable than Zin in all monkeys. After bronchial challenge with A. suum or methacholine, the absolute amplitude of the resistive component of Ztr increased and its zero crossing shifted to higher frequencies. These data can estimate Raw and Rti with the six-element DuBois model. Therefore, in monkeys, Ztr has advantages over other measures of lung function, since it provides a methodology to separate estimates of Raw and Rti. In conclusion, Ztr shows spectral features similar to those reported in healthy and asthmatic humans.

Apoptosis plays an important role in experimental rabies virus infection

Cultured rat prostatic adenocarcinoma (AT3) cells infected with the challenge virus standard (CVS) strain of fixed rabies virus showed characteristic morphologic features of apoptosis, evidence of oligonucleosomal DNA fragmentation, and expression of the Bax protein. CVS-infected Bcl-2-transfected AT3 cells did not demonstrate these features. Adult ICR mice inoculated intracerebrally with CVS showed morphologic changes of apoptosis, DNA fragmentation, and increased Bax expression in neurons, with changes most marked in the hippocampus and cerebral cortex. Ultrastructurally, some neurons demonstrated morphologic features more typical of necrosis. These studies provide evidence that apoptosis plays an important role in the pathogenesis of rabies virus infection.