Influence of MHC class I and II haplotypes on the experimental infection of Mauritian cynomolgus macaques with SHIVSF162P4cy.

Mauritian cynomolgus macaques (MCM) are widely used in human immunodeficiency virus research because of their restricted major histocompatibility complex (MHC) diversity which provides the opportunity to address the influence of host factors on vaccine studies. We herein report the impact of MHC haplotype on the outcome of 21 MCM infections with the CCR5-tropic simian/human immunodeficiency virus (SHIV)(SF162P4cy). MCM were susceptible to SHIV(SF162P4cy) infection as shown by viremia and loss of CD4+ T cells. A significant association between haplotype M7 (class IA, IB, II) and persistent viremia was observed in chronic phase, whereas recombinant class IA haplotype was associated with a reduction of viral RNA during acute infection. Class IB M4 haplotype displayed significantly lower acute phase provirus copy numbers. In addition, statistical analysis indicated a detrimental effect of haplotype M4 (class IA, IB) on the course of infection as indicated by lower CD4+ T-cell levels during chronic infection. A decrease in post-acute phase CD4+ T-cell numbers was also observed in haplotype M2 animals. This is the first report that documents the effects of host MHC class I and II molecules on the SHIV(SF162P4cy) infection in MCM, particularly with regard to the association between recombinant class IA, M4, and M7 haplotypes and the dynamic of viral replication and level of CD4+ T cells.

Mhc haplotype M3 is associated with early control of SHIVsbg infection in Mauritian cynomolgus macaques.

The restricted major histocompatibilty complex of Mauritian cynomolgus macaques confers exceptional potential on this species in human immunodeficiency virus (HIV) vaccine development. However, knowledge of the effects of Mhc genetics on commonly used simian immunodeficiency virus (SIV) and simian/human immunodeficiency virus (SHIV) stocks is incomplete. We determined the effect of Mhc haplotypes on SHIVsbg replication kinetics in a cohort of 25 naïve cynomolgus macaques. Haplotype M3 was associated with a 1.58log(10) reduction in viraemia at day 28 post infection (p.i.). Haplotype M6 was associated with elevated SHIVsbg viraemia at days 28 and 56. No significant effect of Mhc class II haplotypes on viral replication was observed. These data emphasise the importance of genetic characterisation of experimental macaques and advance our understanding of host genetic effects in SIV/SHIV models of HIV infection.

Efficacy of antibiotic-impregnated external ventricular drain catheters.

We prospectively compared the incidence of ventriculitis associated with external ventricular drains (EVD) impregnated with clindamycin and rifampicin with historical controls. We found the use of antibiotic impregnated (AI) EVDs showed a significant decrease in positive cerebrospinal fluid cultures and a significant delay in time to EVD infection.

Low rates of transmission of SRV-2 and STLV-I to juveniles in a population of Macaca fascicularis facilitate establishment of specific retrovirus-free colonies.

BACKGROUND: Prevalence of simian retrovirus-2 (SRV-2) and simian T lymphotropic virus type I (STLV-I), was unknown in 337 captive cynomolgus macaques. METHODS AND RESULTS: Molecular assays identified 29% of animals as SRV-2 mono-infected, 4% of animals as STLV-I mono-infected and 9% of animals as dual-infected. Of 108 juvenile animals, 83% were SRV-2-negative and no juvenile animal was STLV-I-positive. A subsequent study of juvenile macaques over a period of 2.5 years detected no STLV-I and 10 SRV-2 infections, six of which occurred between testing and day of colony formation. The study also highlighted that an anti-SRV-2 serological response does not presuppose infection. Tissue reservoirs of latent SRV-2 were not identified in suspected SRV-2 infections. CONCLUSIONS: Low transmissibility of the viruses present in the parental cohort and improved knowledge of the host response to SRV-2 has facilitated the creation of specific-retrovirus-free colonies of cynomolgus macaques.

Doublecortin expression in the normal and epileptic adult human brain.

Mesial temporal lobe epilepsy (MTLE) is a neurological disorder associated with spontaneous recurrent complex partial seizures and hippocampal sclerosis. Although increased hippocampal neurogenesis has been reported in animal models of MTLE, increased neurogenesis has not been reported in the hippocampus of adult human MTLE cases. Here we showed that cells expressing doublecortin (Dcx), a microtubule-associated protein expressed in migrating neuroblasts, were present in the hippocampus and temporal cortex of the normal and MTLE adult human brain. In particular, increased numbers of Dcx-positive cells were observed in the epileptic compared with the normal temporal cortex. Importantly, 56% of Dcx-expressing cells in the epileptic temporal cortex coexpressed both the proliferative cell marker, proliferating cell nuclear antigen and early neuronal marker, TuJ1, suggesting that they may be newly generated neurons. A subpopulation of Dcx-positive cells in the epileptic temporal cortex also coexpressed the mature neuronal marker, NeuN, suggesting that epilepsy may promote the generation of new neurons in the temporal cortex. This study has identified, for the first time, a novel population of Dcx-positive cells in the adult human temporal cortex that can be upregulated by epilepsy and thus, raises the possibility that these cells may have functional significance in the pathophysiology of epilepsy.

The Mhc class II DRB genotype of Macaca fascicularis does not influence infection by simian retrovirus type 2.

Simian retrovirus type 2 (SRV-2) is a natural pathogen of Macaca fascicularis. Although SRV-2 may be endemic in macaque colonies, it is not necessarily detected in all individuals suggesting differential susceptibility to SRV-2; factors contributing to this susceptibility are not fully understood. We have investigated the role of host genetic origin on virus susceptibility. We have shown that high levels of anti-SRV-2 antibodies correlate with failure to establish persistent virus infection, thus we targeted our genetic analysis of virus susceptibility with an investigation of the role of the polymorphic macaque major histocompatibility complex (MHC) class II locus. DRB genotypes, both novel and previously characterised, were identified in individuals and family groups. A discordance with SRV-2 infection status suggests that an Mhc II DRB genotype is not overtly associated with the outcome of viral infection.

Adult neurogenesis in mesial temporal lobe epilepsy: a review of recent animal and human studies.

Mesial temporal lobe epilepsy (mTLE) is a neurological condition characterized by the occurrence of spontaneous recurrent seizures originating from mesial structures involving the hippocampus within the temporal lobe. This condition is often associated with pathological features in the hippocampus such as neuronal cell loss, widening of the granule cell layer, astrogliosis and mossy fibre spouting. At present, the mechanisms underlying these pathological features are unclear. However, recent advances in adult neurogenesis studies in mTLE animals and patients suggest that newly generated neurons may contribute to the pathogenesis of ongoing epileptogenesis. This article will review the recent animal and human studies on adult neurogenesis in mTLE and discuss how these results suggests that adult endogenous neurogenesis may not always be reparative in the mTLE and may be targeted in new therapeutic strategies for mTLE.

Basilar tip aneurysm - adenosine induced asystole for the treatment of a basilar tip aneurysm following failure of temporary clipping.

We report on a giant basilar tip aneurysm in a 48-year-old woman that could not be clipped despite temporary occlusion of the basilar trunk. Adenosine induced cardiac asystole reduced the aneurysm's wall tension and coupled with increased exposure resulting from brain relaxation allowed for the aneurysm to be satisfactorily occluded via an extended right pterional craniotomy. In difficult vascular cases, adenosine induced cardiac standstill is a useful technique which may allow for technical success when other methods such as temporary clipping fail. It acts to both reduce aneurysm wall tension and increase operative exposure by reducing vascular, and hence brain volume.

Obstetric deaths in Bangladesh, 1996-1997.

OBJECTIVES: The purpose of this study was to measure and to describe obstetric deaths in Bangladesh. METHODS: We reviewed hospital records and interviewed health workers in clinic sites and field workers who cared for pregnant women. RESULTS: We obtained case reports of 28998 deaths of women aged 10-50, of which 8562 (29.5%) were maternal deaths. Most (7086, 82.8%) of these deaths were due to obstetric causes. The most common causes of direct obstetric death were eclampsia (34.3%), hemorrhage (27.9%), and obstructed and/or prolonged labor (11.3%). National direct obstetric death rate was estimated to be 16.9 per 100,000 women. CONCLUSIONS: Efforts to reduce fertility in Bangladesh have led to an estimated 49% reduction in the maternal mortality rate per 1000 women during the past 18 years. Variations in maternal mortality suggest the need to develop local strategies to improve obstetric care.

Changes in the mRNAs encoding voltage-gated sodium channel types II and III in human epileptic hippocampus.

Studies with animal seizure models have indicated that changes in temporal and spatial expression of voltage-gated sodium channels may be important in the pathology of epilepsy. Here, by using in situ hybridisation with previously characterised subtype-selective oligonucleotide probes [Whitaker et al. (2000) J. Comp. Neurol. 422, 123-139], we have compared the cellular expression of all four brain alpha-subunit sodium channel mRNAs in "normal" and epileptic hippocampi from humans. Neuronal cell loss was observed in all regions of the hippocampus of diseased patients, indicating that sclerosis had occurred. Losses of up to 40% compared to post-mortem controls were observed which were statistically significant in all regions studied (dentate gyrus, hilus, and CA1-3). To assess mRNA levels of the different alpha-subtypes in specific subregions, control and diseased tissue sections were hybridised to subtype-specific probes. To quantify any changes in expression while allowing for cell loss, the sections were processed for liquid emulsion autoradiography and grain counts were performed on populations of individual neurones in different subregions. No significant differences were found in the expression of type I and VI mRNAs. In contrast, a significant down-regulation of type II mRNA was observed in the epileptic tissue in the remaining pyramidal cells of CA3 (71+/-7% of control, P<0.01), CA2 (81+/-8% of control, P<0.05) and CA1 (72+/-6% of control, P<0.05) compared with control tissue. Additionally, a significant up-regulation in type III mRNA in epileptic CA4 pyramidal cells (145+/-7% of control, P<0.05) was observed. It is not clear whether these changes play a causal role in human epilepsy or whether they are secondary to seizures or drug treatment; further studies are necessary to investigate these alternatives. However, it is likely that such changes would affect the intrinsic excitability of hippocampal neurones.

Magnesium sulfate in the management of patients with Fisher Grade 3 subarachnoid hemorrhage: a pilot study.

OBJECTIVE: To evaluate the effect of magnesium sulfate (MgSO4) on the clinical course of patients with severe aneurysmal subarachnoid hemorrhage (SAH). METHODS: Ten patients with Fisher Grade 3 aneurysmal SAH were evaluated. The patients were given a bolus as well as a constant infusion of intravenous MgSO4 up to 10 days postictus. Blood magnesium levels were obtained to adjust the daily requirement of MgSO4. The goal was to raise the serum level to 2.0 to 2.5 mmol/L or twice the baseline serum level. Daily transcranial Doppler (TCD) ultrasonography was performed on each patient, insonating both anterior cerebral and middle cerebral arteries. Further management followed standard protocols, including the use of nimodipine and hypervolemic therapy. TCD ultrasonographic findings, as well as clinical evidence of cerebral vasospasm, were documented. All patients had a 3-month assessment using the Glasgow Outcome Scale. RESULTS: After administration of a 20 mmol MgSO4 bolus infusion and an average daily continuous infusion of 84.7 mmol, 8 of 10 patients achieved the predetermined serum magnesium levels. No adverse affects were noted during the infusions. Five patients exhibited evidence of vasospasm on TCD ultrasonography; vasospasm was severe in two patients (velocities, >200 cm/s). Three patients, including the two patients in whom TCD ultrasonography demonstrated severe vasospasm, exhibited clinical evidence of vasospasm. Two patients had a Glasgow Outcome Scale score of 3; the remainder had Glasgow Outcome Scale scores of 5. CONCLUSION: Administration guidelines for the use of MgSO4 in aneurysmal SAH were established. A prospective double-blind placebo-controlled trial is required to establish the effectiveness of MgSO4 for treating vasospasm in aneurysmal SAH.

Aspartoacylase gene transfer to the mammalian central nervous system with therapeutic implications for Canavan disease.

With the ultimate goal of developing safe and effective in vivo gene therapy for the treatment of Canavan disease and other neurological disorders, we developed a non-viral lipid-entrapped, polycation-condensed delivery system (LPD) for central nervous system gene transfer, in conjunction with adeno-associated virus (AAV)-based plasmids containing recombinant aspartoacylase (ASPA). The gene delivery system was tested in healthy rodents and primates, before proceeding to preliminary studies in 2 children with Canavan disease. Toxicity and expression testing was first carried out in human 293 cells, which demonstrated effective transduction of cells and high levels of functional ASPA activity. We performed in vivo toxicity and expression testing of LPD/pAAVaspa and LPD/pAAVlac in rodents, which demonstrated widespread gene expression for more than 10 months after intraventricular delivery, and local expression in deep brain nuclei and white matter tracts for more than 6 months after intraparenchymal injections, with no significant adverse effects. We also performed intraventricular delivery of LPD/pAAVaspa to 2 cynomologous monkeys, with 2 additional monkeys receiving LPD and saline controls. None of the monkeys demonstrated significant adverse effects, and at 1 month the 2 LPD/pAAVaspa monkeys were positive for human ASPA transcript by reverse transcriptase polymerase chain reaction of brain tissue punches. Finally, we performed the first in vivo gene transfer study for a human neurodegenerative disease in 2 children with Canavan disease to assess the in vivo toxicity and efficacy of ASPA gene delivery. Our results suggest that LPD/pAAVaspa is well tolerated in human subjects and is associated with biochemical, radiological, and clinical changes.

Changes in subarachnoid hemorrhage mortality, incidence, and case fatality in New Zealand between 1981-1983 and 1991-1993.

BACKGROUND AND PURPOSE: As with total stroke, mortality rates from subarachnoid hemorrhage (SAH) have declined in New Zealand since the mid-1970s. Data from the Auckland Region Stroke studies allow an understanding of reasons for the change, as SAH incidence and 28-day case fatality rates were measured as part of population-based stroke registers. METHODS: National death registrations were used to describe the trends in mortality rates from SAH (International Classification of Diseases [ICD] code 430) among men and women in New Zealand. Changes in incidence and case fatality rates were determined from 2 large-scale population-based stroke registries carried out in 1981-1983 and 10 years later in Auckland. Similar methodology and case ascertainment techniques were used in both studies. RESULTS: The mortality rates from SAH declined in both men and women after the mid-1970s. The mortality rate remained higher among women than men. The incidence of SAH was lower in 1991-1993 (11.3 per 100,000) compared with 1981-1983 (14.6 per 100,000). In the younger age groups, the decrease was mostly due to a lower incidence among men, whereas in the older age groups women older than 65 years had a lower incidence. There was no consistent change in case fatality rates between the 2 periods in either men or women. CONCLUSIONS: Mortality rates from SAH have decreased in both men and women. This decrease may be explained by a decrease in the incidence of SAH, because case fatality rates showed no change.

Too little, too late: does tirilazad mesylate reduce fatigue after subarachnoid hemorrhage?

OBJECTIVE: Trials assessing drug effectiveness for treatment of subarachnoid hemorrhage (SAH) often use mortality rates and Glasgow Outcome Scale scores as outcome measures. Neuropsychological and psychosocial measures might be more sensitive to outcomes, especially for patients of better-grade status. METHODS: Eighteen of a total of 31 patients enrolled in the New Zealand arm of the Upjohn international, double-blind, therapeutic trial of tirilazad mesylate for women with SAH were assessed neuropsychologically and psychosocially 3 months after SAH. The 13 not assessed either had died or remained vegetative (9 patients), did not speak English (1 patient), or did not consent (3 patients). The drug code was broken after all assessments had been scored. RESULTS: Sixteen of the 31 patients had received the drug and 15 the vehicle. There were no differences between the two groups with respect to age, grades assessed at admission and 14 weeks after SAH, Glasgow Outcome Scale scores assessed at 3 months, or mortality rates. In the subgroup assessed neuropsychologically, nine patients were in each of the drug- and vehicle-treated groups. No differences were found with respect to grades, Glasgow Outcome Scale scores, or values for an index that measured cognitive impairment in all tests, but vehicle-treated patients were more impaired with respect to measures of concentration, sustained attention, and psychomotor speed (P < 0.02), as well as debilitating fatigue (P < 0.01). CONCLUSION: The finding that the patients in the drug-treated group exhibited fewer impairments typical of diffuse cortical damage could be viewed as being consistent with the hypothesis that tirilazad mesylate protects neurons. Given the small size of this study, these results require confirmation with larger patient groups. Future drug trials should consider including neuropsychological tests in assessments of outcomes after SAH. If this is too costly, questions regarding fatigue levels might prove worthwhile.

Expression of Fos, Jun, and Krox family proteins in Alzheimer's disease.

Apoptosis is an active process of cell death characterized by distinct morphological features and is often the end result of a genetic program of events, i.e., programmed cell death (PCD). There is growing evidence supporting a role for apoptosis and/or PCD in Alzheimer's disease (AD), based on DNA fragmentation studies and recent findings of increased levels of inducible transcription factors (ITFs) such as c-Jun in AD brains. We have characterized the expression of a large range of ITFs (c-Fos, Fos B, Fos-related antigens, c-Jun, Jun B, Jun D, Krox20, and Krox24) using multiple antisera in AD postmortem hippocampi and compared this with human control hippocampi as well as Huntington's disease hippocampi and human epilepsy biopsy tissue. We found little evidence of nuclear expression of any ITF except c-Jun in the human postmortem tissue, compared with nuclear staining in biopsy tissue. We found some evidence for increased levels of c-Jun and Krox24 protein and krox24 mRNA in the CA1 region of AD hippocampi, suggesting that PCD may be involved in the pathogenesis of AD. In general, staining characteristics of ITFs varied with different antisera directed against the same protein, indicating the need for caution when interpreting results.

Neurological and psychosocial outcome 4 to 7 years after subarachnoid hemorrhage.

OBJECTIVE: Previous studies have demonstrated that many patients with good neurological outcomes still experience excessive fatigue, cognitive impairments, and lowered work status 1 year after subarachnoid hemorrhage (SAH). Does recovery continue for many years or are survivors of SAH left with permanent disabilities? We describe the long-term outcome. METHODS: Approximately 50% (n = 123) of the patients who survived SAH for more than 3 years from a population of 1.5 million and who had participated in research studies at the time of their SAH were interviewed 4 to 7 years later by telephone or questionnaire. Participants did not differ from the 126 unsurveyed survivors in age, gender, SAH grades, aneurysm sites, or complications. RESULTS: Most patients thought their recovery to be satisfactory to good, although some reported memory problems (41%), headaches (16.5%), daytime sleepiness (35%), problems sleeping at night (26%), a reduced ability to work (20%), and a changed personality (48.3%). Many had reduced their smoking and drinking. Each of 24 of the 121 participants for whom seizure data were available (all with clipped aneurysms) had suffered at least one seizure, but only each of 10 had suffered two or more seizures since hospital discharge. Relative youth was the only significant predictor of seizures, with strong trends observed between seizures and a poor Glasgow Outcome Scale score at 10 weeks or between seizures and an ischemic neurological deficit. No evidence for the effectiveness of prophylactic anticonvulsants was demonstrated. CONCLUSION: Survivors of SAH continue to recover for years and develop good coping skills and a positive attitude toward their recovery, even when they experience ongoing problems. Few are left with disabling headaches or epilepsy.

Loss of A1 adenosine receptors in human temporal lobe epilepsy.

Using quantitative receptor autoradiographic methods we have examined A1 adenosine receptors, adenosine uptake sites, benzodiazepine receptors, NMDA, AMPA, and kainic acid receptors in temporal lobes removed from patients suffering from complex partial seizures and in normal control post-mortem temporal cortex. Binding to A1 adenosine receptors and NMDA receptors was reduced in epileptic temporal cortex, while the other neurochemical parameters were unchanged. The reason for this A1 receptor loss is unclear as it occurred in both idiopathic and symptomatic cases and thus may be a consequence rather than an initial cause of seizures. However, because adenosine is a powerful anticonvulsant substance, loss of anticonvulsant A1 receptors may contribute to the human epileptic condition. It is also possible that the observed differences in A1 binding are due to autopsy vs. biopsy changes in the levels of A1 adenosine receptors.

In situ evidence for DNA fragmentation in Huntington's disease striatum and Alzheimer's disease temporal lobes.

To test the hypothesis that apoptosis is involved in human brain neurodegenerative disorders, we investigated whether DNA fragmentation occurs in Alzheimer's disease (AD). Huntington's disease (HD) and Parkinson's disease, as well as in temporal lobe epilepsy, using neurologically normal post-mortem human brain tissue as a control. Using in situ end labelling of DNA, we found evidence of DNA fragmentation in cells in temporal cortex and hippocampus from patients with AD and in striatum from those with HD. In contrast, only scattered DNA fragmentation positive cells were detected in the pial surfaces of some of the neurologically normal human brains. Thus, cells in the HD striatum and AD temporal cortex exhibited DNA fragmentation, suggesting that apoptosis may be involved in these disorders.

A prospective study of impairment of cognition and memory and recovery after subarachnoid hemorrhage.

In this prospective study, a series of 89 patients with subarachnoid hemorrhage (SAH), most of whom had a "good" neurological outcome, were assessed with a range of tests of memory and cognition as inpatients and at 10 weeks and 12 months after SAH. On tests of verbal cognition and memory, most patients had scores in the normal range 12 months after SAH. However, a significant number of patients still showed impairment on tests of visuospatial construction and memory, mental flexibility, and psychomotor speed at the 12-month assessment. Statistical analyses were carried out for each test score to see whether aneurysm site, location of blood on the admission computed tomographic scan, vasospasm, ischemia, hydrocephalus, grades at admission to and at discharge from hospital, and Glasgow Outcome Scale score at follow-up were associated with test scores. Aneurysm site was not shown to be associated with performance on any test at any time, and the other complications of SAH had only minimal predictive value. The grade at discharge proved to be the best predictor of impairment of cognition and memory at both follow-up assessments. Older subjects did not recover to the same extent as younger subjects by the 12-month assessment. The authors conclude that the diffuse effects of SAH are more important than focal neuropathology in relation to cognitive impairment in this group of patients.

Brain abscess in the computed tomography era: A 10-year experience from Auckland, New Zealand.

Notes were reviewed for 68 patients with brain abscess diagnosed at Auckland Hospital, Auckland, New Zealand between 1978 and 1988. Mean age was 30 years (range one week to 74 years). There were 48 men and 40% were Maori or Pacific Island Polynesians. Seventy-two per cent of patients had headache, 54% had fever and 72% had lateralizing neurological signs. Thirty-one per cent of abscesses were associated with contiguous infection (otic, sinus, dental). Forty-four per cent were in the frontal lobe. Two abscesses were sterile; 197 bacterial isolates were cultured from the remainder. Fifty-four per cent contained obligate anaerobes, which were the only isolates in 22%. Streptococcus anginosus was the single most common isolate present in 22% of the abscesses. Amoxycillin plus metronidazole provided cover for approximately 95% of the total isolates on the basis of sensitivity testing. Treatment was with surgery and antibiotics in all but three patients, who were cured with antibiotics alone. Sixty per cent had a definitive regimen of penicillin (or ampicillin/amoxycillin) and/or metronidazole, always intravenous initially but subsequently often orally. Median duration of antibiotic treatment was 57 days (range 28 to 206). Seventy-five per cent had initial aspiration, 9% open drainage and 7% were excised initially. Seventy-one per cent had a good functional outcome. Mortality was 8.8%. Factors associated with a poor outcome were trauma as a cause, and delays after admission of more than seven days to diagnosis and/or operation.