Trajectories of brain and hippocampal atrophy in FTD with mutations in MAPT or GRN

OBJECTIVE

To use multiple serial MRI to assess rates and trajectories of brain and hippocampal atrophy in subjects with frontotemporal dementia (FTD) with progranulin (GRN) or microtubule-associated protein tau (MAPT) gene mutations.

METHODS

In this case-control study, we identified 8 subjects with mutations in GRN and 12 subjects with mutations in MAPT who had at least 2 serial MRIs. Serial MRIs were registered to baseline MRI for each subject using 9 df registration and rate of whole brain atrophy was calculated using the boundary-shift integral. Hippocampal volume was measured using Freesurfer. Mixed effects linear regression models were used to model volume change over time in both groups after adjusting for head size, age at baseline, and disease duration at baseline.

RESULTS

The annual rate of whole brain atrophy in the MAPT subjects was 2.4% per year (95% confidence interval [CI] 1.9-2.8). The GRN subjects showed a higher rate of whole brain atrophy at 3.5% per year (95% CI 2.8-4.2; p = 0.01). Rates of hippocampal atrophy were not different across the groups (MAPT = 7.8% [95% CI 3.9-12], GRN = 6.5% [95% CI 1.7-11], p = 0.66). Rates of whole brain atrophy in GRN, and hippocampal atrophy in MAPT, were associated with age, with older subjects showing slower rates of atrophy (p = 0.01 and p < 0.001).

CONCLUSIONS

Subjects with FTD with GRN mutations have a faster rate of whole brain atrophy than subjects with FTD with MAPT mutations, with similar rates of hippocampal atrophy. Rates of atrophy in both groups were associated with age. These findings are important for future treatment trials in FTD that use rates of atrophy as an outcome measure.

Frontotemporal dementia and parkinsonism linked to chromosome 17--the first Polish family

BACKGROUND

Frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17) is a neurodegenerative disorder with various clinical phenotypes. We present the first Central-Eastern European family (Gdansk Family) with FTDP-17 because of a P301L mutation in microtubule-associated protein tau (MAPT).

METHODS

We have studied a family consisting of 82 family members, 39 of whom were genetically evaluated. The proband and her affected brother underwent detailed clinical and neuropsychological examinations.

RESULTS

P301L mutation in MAPT was identified in two affected and five asymptomatic family members. New features included hemispatial neglect and unilateral resting tremor not previously reported for P301L MAPT mutation. Low blood folic acid levels were also detected.

CONCLUSIONS

Our report suggests that FTDP-17 affects patients worldwide, but because of its heterogenous clinical presentation remains underrecognized.

Limits on neutrino emission from gamma-ray bursts with the 40 string IceCube detector

IceCube has become the first neutrino telescope with a sensitivity below the TeV neutrino flux predicted from gamma-ray bursts if gamma-ray bursts are responsible for the observed cosmic-ray flux above 10(18)  eV. Two separate analyses using the half-complete IceCube detector, one a dedicated search for neutrinos from pγ interactions in the prompt phase of the gamma-ray burst fireball and the other a generic search for any neutrino emission from these sources over a wide range of energies and emission times, produced no evidence for neutrino emission, excluding prevailing models at 90% confidence.

The second wave of 2009 pandemic influenza A(H1N1) in New Zealand, January-October 2010

This paper uses data from multiple surveillance systems to describe the experience in New Zealand with the second complete wave of pandemic influenza A(H1N1)2009 in 2010. Measures such as hospitalisation rates suggest the overall impact of influenza A(H1N1)2009 in 2010 was between half and two thirds that of the first wave in 2009. There was considerable regional and sub-regional variation with a tendency for higher activity in areas that experienced low rates in 2009. Demographic characteristics of the second wave were similar to those in 2009 with highest rates seen in children under the age of five years, and in indigenous Māori and Pacific peoples. Hospital services including intensive care units were not under as much pressure as in 2009. Immunisation appears to have contributed to the reduced impact of the pandemic in 2010, particularly for those aged 60 years and older.

The second wave of 2009 pandemic influenza A(H1N1) in New Zealand, January–October 2010

This paper uses data from multiple surveillance systems to describe the experience in New Zealand with the second complete wave of pandemic influenza A(H1N1)2009 in 2010. Measures such as hospitalisation rates suggest the overall impact of influenza A(H1N1)2009 in 2010 was between half and two thirds that of the first wave in 2009. There was considerable regional and sub-regional variation with a tendency for higher activity in areas that experienced low rates in 2009. Demographic characteristics of the second wave were similar to those in 2009 with highest rates seen in children under the age of five years, and in indigenous M?ori and Pacific peoples. Hospital services including intensive care units were not under as much pressure as in 2009. Immunisation appears to have contributed to the reduced impact of the pandemic in 2010, particularly for those aged 60 years and older.

Does TDP-43 type confer a distinct pattern of atrophy in frontotemporal lobar degeneration?

OBJECTIVE

To determine whether TDP-43 type is associated with distinct patterns of brain atrophy on MRI in subjects with pathologically confirmed frontotemporal lobar degeneration (FTLD).

METHODS

In this case-control study, we identified all subjects with a pathologic diagnosis of FTLD with TDP-43 immunoreactive inclusions (FTLD-TDP) and at least one volumetric head MRI scan (n = 42). In each case we applied published criteria for subclassification of FTLD-TDP into FTLD-TDP types 1-3. Voxel-based morphometry was used to compare subjects with each of the different FTLD-TDP types to age- and gender-matched normal controls (n = 30). We also assessed different pathologic and genetic variants within, and across, the different types.

RESULTS

Twenty-two subjects were classified as FTLD-TDP type 1, 9 as type 2, and 11 as type 3. We identified different patterns of atrophy across the types with type 1 showing frontotemporal and parietal atrophy, type 2 predominantly anterior temporal lobe atrophy, and type 3 predominantly posterior frontal atrophy. Within the FTLD-TDP type 1 group, those with a progranulin mutation had significantly more lateral temporal lobe atrophy than those without. All type 2 subjects were diagnosed with semantic dementia. Subjects with a pathologic diagnosis of FTLD with motor neuron degeneration had a similar pattern of atrophy, regardless of whether they were type 1 or type 3.

CONCLUSIONS

Although there are different patterns of atrophy across the different FTLD-TDP types, it appears that genetic and pathologic factors may also affect the patterns of atrophy.

Statins and the Bariatric Patient: Characterization and Perioperative Effects of Statin Therapy in the Gastric Bypass Patient

In surgical patients, statins have been shown to have beneficial effects independent of the lipid-lowering properties. Statin use has not been well studied in the bariatric patient. The objective of this study was to characterize the use of statins in the bariatric surgery patient and compare outcomes, including complications, weight loss, and changes in comorbidities. A retrospective chart review of patients undergoing bariatric surgery between 2005 and 2008 was conducted. Four hundred forty surgical patients charts were reviewed, of which 151 (34%) were taking a perioperative statin. The two groups were similar in length of stay, baseline body mass index, type of procedure, smoking status, and hospital charges. However, the statin group was older, more likely male, and with more baseline comorbidities, including hypertension (HTN), hyperlipidemia (HLD), diabetes mellitus (DM), coronary artery disease, and obstructive sleep apnea (OSA). There was no statistical significance noted in the any complication or death. There was no difference in weight loss over time between the two groups. The statin group was more likely to report resolution in HLD (27.5 vs 9.5%, P = 0.004), but not DM, HTN, or OSA. In summary, there are differences in bariatric patients who take statins compared with their counterparts. Statins with gastric bypass may improve resolution of HLD, which may eventually alter long-term cardiac risk in these patients.

Statins and the bariatric patient: characterization and perioperative effects of statin therapy in the gastric bypass patient

In surgical patients, statins have been shown to have beneficial effects independent of the lipid-lowering properties. Statin use has not been well studied in the bariatric patient. The objective of this study was to characterize the use of statins in the bariatric surgery patient and compare outcomes, including complications, weight loss, and changes in comorbidities. A retrospective chart review of patients undergoing bariatric surgery between 2005 and 2008 was conducted. Four hundred forty surgical patients charts were reviewed, of which 151 (34%) were taking a perioperative statin. The two groups were similar in length of stay, baseline body mass index, type of procedure, smoking status, and hospital charges. However, the statin group was older, more likely male, and with more baseline comorbidities, including hypertension (HTN), hyperlipidemia (HLD), diabetes mellitus (DM), coronary artery disease, and obstructive sleep apnea (OSA). There was no statistical significance noted in the any complication or death. There was no difference in weight loss over time between the two groups. The statin group was more likely to report resolution in HLD (27.5 vs 9.5%, P = 0.004), but not DM, HTN, or OSA. In summary, there are differences in bariatric patients who take statins compared with their counterparts. Statins with gastric bypass may improve resolution of HLD, which may eventually alter long-term cardiac risk in these patients.

TMEM106B regulates progranulin levels and the penetrance of FTLD in GRN mutation carriers

OBJECTIVES

To determine whether TMEM106B single nucleotide polymorphisms (SNPs) are associated with frontotemporal lobar degeneration (FTLD) in patients with and without mutations in progranulin (GRN) and to determine whether TMEM106B modulates GRN expression.

METHODS

We performed a case-control study of 3 SNPs in TMEM106B in 482 patients with clinical and 80 patients with pathologic FTLD-TAR DNA-binding protein 43 without GRN mutations, 78 patients with FTLD with GRN mutations, and 822 controls. Association analysis of TMEM106B with GRN plasma levels was performed in 1,013 controls and TMEM106B and GRN mRNA expression levels were correlated in peripheral blood samples from 33 patients with FTLD and 150 controls.

RESULTS

In our complete FTLD patient cohort, nominal significance was identified for 2 TMEM106B SNPs (top SNP rs1990622, p(allelic) = 0.036). However, the most significant association with risk of FTLD was observed in the subgroup of GRN mutation carriers compared to controls (corrected p(allelic) = 0.0009), where there was a highly significant decrease in the frequency of homozygote carriers of the minor alleles of all TMEM106B SNPs (top SNP rs1990622, CC genotype frequency 2.6% vs 19.1%, corrected p(recessive) = 0.009). We further identified a significant association of TMEM106B SNPs with plasma GRN levels in controls (top SNP rs1990622, corrected p = 0.002) and in peripheral blood samples a highly significant correlation was observed between TMEM106B and GRN mRNA expression in patients with FTLD (r = -0.63, p = 7.7 × 10(-5)) and controls (r = -0.49, p = 2.2 × 10(-10)).

CONCLUSIONS

In our study, TMEM106B SNPs significantly reduced the disease penetrance in patients with GRN mutations, potentially by modulating GRN levels. These findings hold promise for the development of future protective therapies for FTLD.

Distribution and morphology of the catecholaminergic neural elements in the human hypothalamus

Previous studies have demonstrated that catecholaminergic, tyrosine hydroxylase (TH)-immunoreactive (IR) perikarya and fibers are widely distributed in the human hypothalamus. Since TH is the key and rate-limiting enzyme for catecholaminergic synthesis, these IR neurons may represent dopaminergic, noradrenergic or adrenergic neural elements. However, the distribution and morphology of these neurotransmitter systems in the human hypothalamus is not entirely known. Since the different catecholaminergic systems can be detected by identifying the neurons containing the specific key enzymes of catecholaminergic synthesis, in the present study we mapped the catecholaminergic elements in the human hypothalamus using immunohistochemistry against the catecholaminergic enzymes, TH, dopamine beta-hydroxylase (DBH) and phenylethanolamine-N-methyltransferase (PNMT). Only a few, PNMT-IR, adrenergic neuronal elements were found mainly in the infundibulum and the periventricular zone. DBH-IR structures were more widely distributed in the human hypothalamus occupying chiefly the infundibulum/infundibular nucleus, periventricular area, supraoptic and paraventricular nuclei. Dopaminergic elements were detected by utilizing double label immunohistochemistry. First, the DBH-IR elements were visualized; then the TH-IR structures, that lack DBH, were detected with a different chromogen. In our study, we conclude that all of the catecholaminergic perikarya and the majority of the catecholaminergic fibers represent dopaminergic neurons in the human hypothalamus. Due to the extremely small number of PNMT-IR, adrenergic structures in the human hypothalamus, the DBH-IR fibers represent almost exclusively noradrenergic neuronal processes. These findings suggest that the juxtapositions between the TH-IR and numerous peptidergic systems revealed by previous reports indicate mostly dopaminergic synapses.

Natural killer cell-enriched donor lymphocyte infusions from A 3-6/6 HLA matched family member following nonmyeloablative allogeneic stem cell transplantation

Infusing natural killer (NK) cells following transplantation may allow less infections and relapse with little risk of acute graft-versus-host disease (aGVHD). We delivered 51 total NK cell-enriched donor lymphocyte infusions (DLIs) to 30 patients following a 3-6/6 HLA matched T cell-depleted nonmyeloablative allogeneic transplant. The primary endpoint of this study was feasibility and safety. Eight weeks following transplantation, donor NK cell-enriched DLIs were processed using a CD56(+) selecting column with up to 3 fresh infusions allowed. Toxicity, relapse, and survival were monitored. T cell phenotype, NK cell functional recovery, and KIR typing were assessed for association with outcomes. Fourteen matched and 16 mismatched transplanted patients received a total of 51 NK cell-enriched DLIs. Selection resulted in 96% (standard deviation [SD] 8%) purity and 83% (SD 21%) yield in the matched setting and 97% (SD 3%) purity and 77% (SD 24%) yield in the mismatched setting. The median number of CD3(-) CD56(+) NK cells infused was 10.6 (SD 7.91) x 10(6) cells/kg and 9.21 (SD 5.6) x 10(6) cells/kg, respectively. The median number of contaminating CD3(+)CD56(-) T cells infused was .53 (1.1) x 10(6) and .27 (.78) x 10(6) in the matched and mismatched setting, respectively. Only 1 patient each in the matched (n = 14) or mismatched (n = 16) setting experienced severe aGVHD with little other toxicity attributable to the infusions. Long-term responders with multiple NK cell-enriched infusions and improved T cell phenotypic recovery had improved duration of responses (p = .0045) and overall survival (OS) (P = .0058). A 1-step, high-yield process is feasible, and results in high doses of NK cells infused with little toxicity. NK cell-enriched DLIs result in improved immune recovery and outcomes for some. Future studies must assess whether the improved outcomes are the direct result of the high doses and improved NK cell function or other aspects of immune recovery.

Extending the search for neutrino point sources with IceCube above the horizon

Point source searches with the IceCube neutrino telescope have been restricted to one hemisphere, due to the exclusive selection of upward going events as a way of rejecting the atmospheric muon background. We show that the region above the horizon can be included by suppressing the background through energy-sensitive cuts. This improves the sensitivity above PeV energies, previously not accessible for declinations of more than a few degrees below the horizon due to the absorption of neutrinos in Earth. We present results based on data collected with 22 strings of IceCube, extending its field of view and energy reach for point source searches. No significant excess above the atmospheric background is observed in a sky scan and in tests of source candidates. Upper limits are reported, which for the first time cover point sources in the southern sky up to EeV energies.

Trends in non-metastatic prostate cancer management in the Northern and Yorkshire region of England, 2000-2006

Background:

Our objective was to analyse variation in non-metastatic prostate cancer management in the Northern and Yorkshire region of England.

Methods:

We included 21 334 men aged ⩾55, diagnosed between 2000 and 2006. Principal treatment received was categorised into radical prostatectomy (11%), brachytherapy (2%), external beam radiotherapy (16%), hormone therapy (42%) and no treatment (29%).

Results:

The odds ratio (OR) for receiving a radical prostatectomy was 1.53 in 2006 compared with 2000 (95% CI 1.26–1.86), whereas the OR for receiving hormone therapy was 0.57 (0.51–0.64). Age was strongly associated with treatment received; radical treatments were significantly less likely in men aged ⩾75 compared with men aged 55–64 years, whereas the odds of receiving hormone therapy or no treatment were significantly higher in the older age group. The OR for receiving radical prostatectomy, brachytherapy or external beam radiotherapy were all significantly lower in the most deprived areas when compared with the most affluent (0.64 (0.55–0.75), 0.32 (0.22–0.47) and 0.83 (0.74–0.94), respectively) whereas the OR for receiving hormone therapy was 1.56 (1.42–1.71).

Conclusions:

This study highlights the variation and inequalities that exist in the management of non-metastatic prostate cancer in the Northern and Yorkshire region of England.

Interpreting Google flu trends data for pandemic H1N1 influenza: the New Zealand experience

For the period of the spread of pandemic H1N1 influenza in New Zealand during 2009, we compared results from Google Flu Trends with data from existing surveillance systems. The patterns from Google Flu Trends were closely aligned with (peaking a week before and a week after) two independent national surveillance systems for influenza-like illness (ILI) cases. It was much less congruent with (delayed by three weeks) data from ILI-related calls to a national free-phone Healthline and with media coverage of pandemic influenza. Some patterns were unique to Google Flu Trends and may not have reflected the actual ILI burden in the community. Overall, Google Flu Trends appears to provide a useful free surveillance system but it should probably be seen as supplementary rather than as an alternative.

Interpreting “Google Flu Trends” data for pandemic H1N1 influenza: The New Zealand experience

For the period of the spread of pandemic H1N1 influenza in New Zealand during 2009, we compared results from Google Flu Trends with data from existing surveillance systems. The patterns from Google Flu Trends were closely aligned with (peaking a week before and a week after) two independent national surveillance systems for influenza-like illness (ILI) cases. It was much less congruent with (delayed by three weeks) data from ILI-related calls to a national free-phone Healthline and with media coverage of pandemic influenza. Some patterns were unique to Google Flu Trends and may not have reflected the actual ILI burden in the community. Overall, Google Flu Trends appears to provide a useful free surveillance system but it should probably be seen as supplementary rather than as an alternative.

Atrophy patterns in IVS10+16, IVS10+3, N279K, S305N, P301L, and V337M MAPT mutations

OBJECTIVE

To use a case-control study to assess and compare patterns of gray matter loss across groups of subjects with different mutations in the microtubule-associated protein tau (MAPT) gene.

METHODS

We identified all subjects from Mayo Clinic, Rochester, Minnesota, that screened positive for mutations in MAPT and had a head MRI (n = 22). Voxel-based morphometry was used to assess patterns of gray matter atrophy in groups of subjects with the IVS10+16, IVS10+3, N279K, S305N, P301L, and V337M mutations compared with age- and sex-matched controls.

RESULTS

All MAPT groups showed gray matter loss in the anterior temporal lobes, with varying degrees of involvement of the frontal and parietal lobes. Within the temporal lobe, the subjects with IVS10+16, IVS10+3, N279K, and S305N mutations (mutations that influence the alternative splicing of tau pre-messenger RNA) all showed gray matter loss focused on the medial temporal lobes. In contrast to these groups, the subjects with P301L or V337M mutations (mutations that affect the structure of the tau protein) both showed gray matter loss focused on the lateral temporal lobes, with a relative sparing of the medial temporal lobe.

CONCLUSION

There seem to be differences in patterns of temporal lobe atrophy across the MAPT mutations, which may aid in the differentiation of the different mutation carriers. Furthermore, there seems to be a possible association between mutation function and pattern of temporal lobe atrophy.

Analysis of rewarming curves in Raynaud's phenomenon of various aetiologies

This study investigated whether a modified Cold Provocation Test could distinguish between 86 normal subjects and 31 patients with Raynaud's phenomenon or 59 with hand arm vibration syndrome (HAVS). Of the HAVS subjects, 56 were seen for medical reports as they were involved in litigation. Their assessments were done in a different location but the same protocol was used. A standardised cold stress was used to reduce the finger temperature to 15 degrees C or less without inducing reflex hyperaemia. This test had acceptable repeatability for subjects without HAVS with an intra-class correlation of 0.7. Baseline temperature, temperature rise in the first 30 seconds and the time taken to rewarm by 5 degrees C were measured. Patients with Raynaud's phenomenon and HAVS had cooler hands than controls. HAVS patients rewarmed most in the first 30 seconds. Patients with Raynaud's phenomenon take longer to rewarm by 5 degrees C than controls or those with HAVS (P<0.001). A baseline difference of >7.5 degrees C between the temperature of the digit and that of the room is unlikely to occur in patients with Raynaud's phenomenon or HAVS. A temperature gain of > or =2.2 degrees C in the first 30 seconds on rewarming combined with a low baseline temperature strongly suggests HAVS. This modified cold provocation test may differentiate between patients with Raynaud's phenomenon, HAVS and controls but this observation requires independent verification in subjects not involved in litigation and tested in the same facility.

Sub-optimal hand sanitiser usage in a hospital entrance during an influenza pandemic, New Zealand, August 2009

The hand hygiene behaviours of the public in response to the current H1N1 influenza pandemic 2009 (or other pandemics) have not previously been described. An observational study was undertaken to examine hand hygiene behaviours by people passing a hand sanitiser station in the foyer of a public hospital in New Zealand in August 2009. Of the 2,941 subjects observed, 449 (18.0%, 95% confidence interval: 16.6, 19.6) used the hand sanitiser. This is a far from optimal result in response to the health promotion initiatives in the setting of a pandemic. These findings suggest the need for more effective health promotion of hand hygiene and also provide baseline measurements for future evaluation of hygiene practices.

Limits on a muon flux from neutralino annihilations in the sun with the IceCube 22-string detector

A search for muon neutrinos from neutralino annihilations in the Sun has been performed with the IceCube 22-string neutrino detector using data collected in 104.3 days of live time in 2007. No excess over the expected atmospheric background has been observed. Upper limits have been obtained on the annihilation rate of captured neutralinos in the Sun and converted to limits on the weakly interacting massive particle (WIMP) proton cross sections for WIMP masses in the range 250-5000 GeV. These results are the most stringent limits to date on neutralino annihilation in the Sun.

GRN 3'UTR+78 C>T is not associated with risk for Parkinson's disease

BACKGROUND AND PURPOSE

A single nucleotide polymorphism in the 3'-untranslated region of the progranulin gene (GRN; 3'UTR+78C>T; rs5848) was reported to alter the risk for frontotemporal lobar degeneration with ubiquitin-positive inclusions (FTLD-U). rs5848 is located within a micro-RNA binding site and affects the expression of GRN.

METHODS

As FTLD-U patients often present with parkinsonism, we investigated the association of GRN rs5848 and risk of Parkinson's disease in two Caucasian patient-control series (n = 1413) from the US and Poland.

RESULTS

No association was observed between rs5848 and susceptibility to Parkinson's disease (individual series and combined analysis).

CONCLUSIONS

This finding shows that GRN rs5848 does not affect the risk of Parkinson's disease in the US and Polish populations.

Voxel-based morphometry patterns of atrophy in FTLD with mutations in MAPT or PGRN

OBJECTIVE

To compare patterns of gray matter loss in subjects with mutations in the progranulin (PGRN) gene to subjects with mutations in the microtubule-associated protein tau (MAPT) gene.

METHODS

We identified all subjects seen at the Mayo Clinic, Rochester, MN, who had screened positive for mutations in PGRN or MAPT and had a head MRI. Twelve cases with mutations in the PGRN gene were matched by time from disease onset to scan to 12 subjects with mutations in the MAPT gene. Voxel-based morphometry was used to assess patterns of gray matter loss in the PGRN and MAPT groups compared to a control cohort, and compared to each other. MAPT subjects were younger than the PGRN subjects; therefore, each group was also compared to a specific age-matched control group.

RESULTS

Both PGRN and MAPT groups showed gray matter loss in frontal, temporal, and parietal lobes compared to controls, although loss was predominantly identified in posterior temporal and parietal lobes in PGRN and anteromedial temporal lobes in MAPT. The MAPT group had greater loss compared to healthy subjects of the same age than the PGRN subjects when compared to healthy subjects of the same age. The MAPT subjects showed greater gray matter loss in the medial temporal lobes, insula, and putamen than the PGRN subjects.

CONCLUSION

These results increase understanding of the biology of these disorders and suggest that patterns of atrophy on MRI may be useful to aid in the differentiation of groups of PGRN and MAPT mutation carriers.

Artificial gravity as a countermeasure to microgravity: a pilot study examining the effects on knee extensor and plantar flexor muscle groups

The goal of this project was to examine the effects of artificial gravity (AG) on skeletal muscle strength and key anabolic/catabolic markers known to regulate muscle mass. Two groups of subjects were selected for study: 1) a 21 day-bed rest (BR) group (n = 7) and 2) an AG group (n = 8), which was subjected to 21 days of 6 degrees head-down tilt bed rest plus daily 1-h exposures to AG (2.5 G at the feet). Centrifugation was produced using a short-arm centrifuge with the foot plate approximately 220 cm from the center of rotation. The torque-velocity relationships of the knee extensors and plantar flexors of the ankle were determined pre- and posttreatment. Muscle biopsy samples obtained from the vastus lateralis and soleus muscles were used for a series of gene expression analyses (mRNA abundance) of key factors implicated in the anabolic vs. catabolic state of the muscle. Post/pre torque-velocity determinations revealed greater decrements in knee extensor performance in the BR vs. AG group (P < 0.04). The plantar flexors of the AG subjects actually demonstrated a net gain in the torque-velocity relationship, whereas in the BR group, the responses declined (AG vs. BR, P < 0.001). Muscle fiber cross-sectional area decreased by approximately 20% in the BR group, whereas no losses were evident in the AG group. RT-PCR analyses of muscle biopsy specimens demonstrated that markers of growth and cytoskeletal integrity were higher in the AG group, whereas catabolic markers were elevated in the BR group. Importantly, these patterns were seen in both muscles. We conclude that paradigms of AG have the potential to maintain the functional, biochemical, and structural homeostasis of skeletal muscle in the face of chronic unloading.

Tuberculosis associated with household crowding in a developed country

BACKGROUND

Tuberculosis (TB) remains an important infectious disease in New Zealand (NZ) and globally, but risk factors for transmission are still poorly understood. This research aimed to identify whether household crowding contributes to TB transmission in NZ.

METHODS

This ecological study used TB surveillance and census data to calculate TB incidence rates by census area unit (CAU). Census data were used to determine CAU characteristics including proportion of household crowding (a bedroom deficit of one or more), proportion of population who are migrants born in high-TB-incidence countries, median household income, and deprivation level. A negative binomial regression model was used to estimate the association between TB incidence and household crowding.

RESULTS

The analysis included 1898 notified TB cases for the 2000-4 period. Univariate analysis showed TB incidence at the CAU level was associated with household crowding, for the total population and for all ethnic and age groups. After adjusting for the covariates of household income, existing TB burden, and proportion of migrants from high-TB-incidence countries, multivariate analysis showed statistically significant associations between TB incidence and household crowding. The incidence rate ratio (IRR) was 1.05 (95% CI 1.02 to 1.08) in the total population and 1.08 (95% CI 1.04 to 1.12) for NZ-born people <40 years.

CONCLUSION

At the CAU level, TB incidence in NZ is associated with household crowding. An individual-based study (e.g. case-control) in recently infected cases (detected by molecular epidemiology techniques) is suggested to complement these findings. Reducing or eliminating household crowding could decrease TB incidence in NZ and globally.

Sources of nitrogen dioxide (NO2) in New Zealand homes: findings from a community randomized controlled trial of heater substitutions

Houses in New Zealand have inadequate space heating and a third of households use unflued gas heaters. As part of a large community intervention trial to improve space heating, we replaced ineffective heaters with more effective, non-polluting heaters. This paper assesses the contribution of heating and household factors to indoor NO2 in almost 350 homes and reports on the reduction in NO2 levels due to heater replacement. Homes using unflued gas heaters had more than three times the level of NO2 in living rooms [geometric mean ratio (GMR) = 3.35, 95% CI: 2.83-3.96, P < 0.001] than homes without unflued gas heaters, whereas homes using gas stove-tops had significantly elevated living room NO2 levels (GMR = 1.42, 95% CI: 1.05-1.93, P = 0.02). Homes with heat pumps, flued gas heating, or enclosed wood burners had significantly lower levels of NO2 in living areas and bedrooms. In homes that used unflued gas heaters as their main form of heating at baseline, the intervention was associated with a two-third (67%) reduction in NO2 levels in living rooms, when compared with homes that continued to use unflued gas heaters. Reducing the use of unflued gas heating would substantially lower NO2 exposure in New Zealand homes.

PRACTICAL IMPLICATIONS

Understanding the factors influencing indoor NO2 levels is critical for the assessment and control of indoor air pollution. This study found that homes that used unflued gas combustion appliances for heating and cooking had higher NO2 levels compared with homes where other fuels were used. These findings require institutional incentives to increase the use of more effective, less polluting fuels, particularly in the home environment.

Abnormal TDP-43 immunoreactivity in AD modifies clinicopathologic and radiologic phenotype

BACKGROUND

TAR DNA-binding protein 43 (TDP-43) is one of the major disease proteins in frontotemporal lobar degeneration with ubiquitin immunoreactivity. Approximately one-fourth of subjects with pathologically confirmed Alzheimer disease (AD) have abnormal TDP-43 (abTDP-43) immunoreactivity. The aim of this study was to determine whether subjects with pathologically confirmed AD and abTDP-43 immunoreactivity have distinct clinical, neuropsychological, imaging, or pathologic features compared with subjects with AD without abTDP-43 immunoreactivity.

METHODS

Eighty-four subjects were identified who had a pathologic diagnosis of AD, neuropsychometric testing, and volumetric MRI. Immunohistochemistry for TDP-43 was performed on sections of hippocampus and medial temporal lobe, and positive cases were classified into one of three types. Neuropsychometric data were collated and compared in subjects with and without abTDP-43 immunoreactivity. Voxel-based morphometry was used to assess patterns of gray matter atrophy in subjects with and without abTDP-43 immunoreactivity compared with age- and sex-matched controls.

RESULTS

Twenty-nine (34%) of the 84 AD subjects had abTDP-43 immunoreactivity. Those with abTDP-43 immunoreactivity were older at onset and death and performed worse on the Clinical Dementia Rating scale, Mini-Mental State Examination, and Boston Naming Test than subjects without abTDP-43 immunoreactivity. Subjects with and without abTDP-43 immunoreactivity had medial temporal and temporoparietal gray matter loss compared with controls; however, those with abTDP-43 immunoreactivity showed greater hippocampal atrophy. Multivariate logistic regression adjusting for age at death demonstrated that hippocampal sclerosis was the only pathologic predictor of abTDP-43 immunoreactivity.

CONCLUSIONS

The presence of abnormal TDP-43 immunoreactivity is associated with a modified Alzheimer disease clinicopathologic and radiologic phenotype.