The association between intraoperative correction of Dupuytren's disease and residual postoperative contracture

The purpose of this study was to determine whether preoperative contracture and the amount of intraoperative correction can be used to predict the postoperative outcome of fasciectomy for Dupuytren's disease. A prospective study of 52 patients undergoing primary fasciectomy during an 18 month period was undertaken. The contracture of each joint was measured preoperatively, after fasciectomy during the operation and 6 months after surgery. Forty-two metacarpophalangeal (MCPJ) and 58 proximal interphalangeal (PIPJ) joints were treated surgically. Full intraoperative correction was achieved in 41 MCPJs. Thirty-seven had full correction at follow-up. Full intraoperative correction was obtained in 35 PIPJs and 13 had complete correction at follow-up. The extent of the preoperative deformity was a significant predictor of complete intraoperative correction. The extent of both preoperative deformity and intraoperative correction were significant predictors of loss of surgical correction after operation.

Sulindac Sulfide Selectively Induces Apoptosis of Human Breast Tumor Cells by Inhibiting PDE5A, Elevating cGMP, and Activating PKG

Nonsteroidal anti-inflammatory drugs (NSAIDs) and cyclooxygenase (COX)-2 selective inhibitors display promising antineoplastic activity, but the gastrointestinal, renal, and cardiovascular toxicities that result from COX inhibition limit their clinical utility for cancer chemoprevention. Previous studies suggest that the pro-apoptotic activity of these drugs may be due to a COX-independent mechanism involving cyclic guanosine monophosphate (cGMP) phosphodiesterase (PDE) inhibition. However, the specific PDE isozyme(s) responsible has not yet been identified. Here we used the NSAID sulindac sulfide (SS) to further study cGMP PDE as a potential molecular target of the NSAIDs for breast cancer chemoprevention. SS inhibited growth and induced apoptosis of human SK-BR-3 and MDA-MB-231 breast tumor cells, while normal human mammary epithelial cells (HMEC) were less sensitive. SS also inhibited cGMP PDE activity from tumor cell lysates at concentrations comparable to those required for apoptosis, while appreciably higher concentrations were necessary to inhibit activity from HMEC lysates or cAMP PDE activity from any of the cell lysates. Additionally, SS increased intracellular cGMP concentrations and induced protein kinase G (PKG) activity in MDA-MB-231 cells as determined by ELISA and increased levels of phosphorylated VASP, a known PKG substrate, respectively. Moreover, pretreatment with the guanylyl cyclase inhibitor LY83583 desensitized the breast tumor cells to the growth-inhibitory activity of SS, likely by suppressing intracellular cGMP levels. The guanylyl cyclase activator NOR-3 and the cGMP PDE inhibitors MY5445 and trequinsin inhibited tumor cell growth, while the adenylyl cyclase activator forskolin and other PDE inhibitors had no effect. HMEC were found to express several cGMP hydrolyzing PDE isozymes (PDE1, 5, and 9), while the breast tumor cells expressed predominantly PDE5, which was confirmed to be sensitive to inhibition by SS using a recombinant enzyme. This work demonstrates that inhibition of PDE5A, elevation of cGMP, and activation of PKG are responsible for the pro-apoptotic effects of SS in human breast tumor cells and that differential expression of PDE isozymes between normal and tumor cells may explain the tumor selectivity of NSAIDs. These data also suggest that it may be feasible to develop NSAID derivatives with increased selectivity for inhibiting PDE5 and decreased COX-inhibitory activity, which would potentially improve safety and efficacy for breast cancer chemoprevention.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1041.

Alpha-synuclein deficiency in the C57BL/6JOlaHsd strain does not modify disease progression in the ME7-model of prion disease

We previously detailed how intrahippocampal inoculation of C57BL/6J mice with murine modified scrapie (ME7) leads to chronic neurodegeneration (Cunningham C, Deacon R, Wells H, Boche D, Waters S, Diniz CP, Scott H, Rawlins JN, Perry VH (2003) Eur J Neurosci 17:2147-2155.). Our characterization of the ME7-model is based on inoculation of this murine modified scrapie agent into C57BL/6J mice from Harlan laboratories. This agent in the C57BL/6J host generates a disease that spans a 24-week time course. The hippocampal pathology shows progressive misfolded prion (PrP(Sc)) deposition, astrogliosis and leads to behavioural dysfunction underpinned by the early synaptic loss that precedes neuronal death. The Harlan C57BL/6J, although widely used as a wild type mouse, are a sub-strain harbouring a spontaneous deletion of alpha-synuclein with the full description C57BL/6JOlaHsd. Recently alpha-synuclein has been shown to ameliorate the synaptic loss in a mouse model lacking the synaptic chaperone CSP-alpha. This opens a potential confound of the ME7-model, particularly with respect to the signature synaptic loss that underpin the physiological and behavioural dysfunction. To investigate if this strain-selective loss of a candidate disease modifier impacts on signature ME7 pathology, we compared cohorts of C57BL/6JOlaHsd (alpha-synuclein negative) with the founder strain from Charles Rivers (C57BL/6JCrl, alpha-synuclein positive). There were subtle changes in behaviour when comparing control animals from the two sub-strains indicating potentially significant consequences for studies assuming neurobiogical identity of both strains. However, there was no evidence that the absence of alpha-synuclein modifies disease. Indeed, accumulation of PrP(Sc), synaptic loss and the behavioural dysfunction associated with the ME7-agent was the same in both genetic backgrounds. Our data suggest that alpha-synuclein deficiency does not contribute to the compartment specific processes that give rise to prion disease mediated synaptotoxicity and neurodegeneration.

Abnormally phosphorylated tau is associated with neuronal and axonal loss in experimental autoimmune encephalomyelitis and multiple sclerosis

The pathological correlate of clinical disability and progression in multiple sclerosis is neuronal and axonal loss; however, the underlying mechanisms are unknown. Abnormal phosphorylation of tau is a common feature of some neurodegenerative disorders, such as Alzheimer's disease. We investigated the presence of tau hyperphosphorylation and its relationship with neuronal and axonal loss in chronic experimental autoimmune encephalomyelitis (CEAE) and in brain samples from patients with secondary progressive multiple sclerosis. We report the novel finding of abnormal tau phosphorylation in CEAE. We further show that accumulation of insoluble tau is associated with both neuronal and axonal loss that correlates with progression from relapsing-remitting to chronic stages of EAE. Significantly, analysis of secondary progressive multiple sclerosis brain tissue also revealed abnormally phosphorylated tau and the formation of insoluble tau. Together, these observations provide the first evidence implicating abnormal tau in the neurodegenerative phase of tissue injury in experimental and human demyelinating disease.

Cardiovascular outcomes among sildenafil users: results of the International Men's Health Study

AIM

To assess the incidence of serious cardiovascular disease (CVD) events [i.e. myocardial infarction (MI) and stroke] and all-cause mortality in men with erectile dysfunction (ED) who received prescriptions for sildenafil.

METHODS

The International Men's Health Study (IMHS) was a prospective, observational cohort study of patients with ED and a new or existing prescription for sildenafil. Baseline and follow-up questionnaires provided information on demographics, CVD risk factors and ED. Postevent questionnaires were mailed to patients following possible nonfatal CVD events to collect information related to exposure to sildenafil/ED treatments before the event.

RESULTS

Thirty-five CVD events were reported in 30 patients in the analysis set (n = 3813). The incidence of all-cause mortality, MI and stroke was 0.4, 0.6 and 0.1 per 100 patient-years of observation respectively. Among the six men who reported using sildenafil in the month before a nonfatal CVD event, two reported use in the 24 h before the event.

CONCLUSION

The results of the IMHS support previous reports that ED and CVD are often comorbid and share risk factors.

The moving platform after-effect reveals dissociation between what we know and how we walk

Gait adaptation is crucial for coping with varying terrain and biological needs. It is also important that any acquired adaptation is expressed only in the appropriate context. Here we review a recent series of experiments which demonstrate inappropriate expression of gait adaptation. We showed that a brief period of walking onto a platform previously experienced as moving results in a large forward sway despite full awareness of the changing context. The adaptation mechanisms involved in this paradigm are extremely fast, just 1-2 discrete exposures to the moving platform results in a motor after-effect. This after-effect still occurs even if subjects deliberately attempt to suppress it. However it disappears when the location or method of gait is altered, indicating that after-effect expression is context dependent. Conversely, making gait self-initiated increased sway during the after-effect. This after-effect demonstrates a profound dissociation between knowledge and action. The absence of generalisation suggests a simple form of motor learning. However, persistent expression of gait after-effects may be dependent on an intact cerebral cortex. The fact that the after-effect is greater during self-initiated gait, and is context dependent, would be consistent with the involvement of supraspinal areas.

Remyelination can be extensive in multiple sclerosis despite a long disease course

Experimental studies using models of multiple sclerosis (MS) indicate that rapid and extensive remyelination of inflammatory demyelinated lesions is not only possible, but is the normal situation. The presence of completely remyelinated MS lesions has been noted in numerous studies and routine limited sampling of post mortem MS material suggests that remyelination may be extensive in the early stages but eventually fails. However, visual macroscopic guided sampling tends to be biased towards chronic demyelinated lesions. Here we have extensively sampled cerebral tissue from two MS cases to investigate the true extent of remyelination. Sections were cut from 185 cerebral tissue blocks and stained with haematoxylin and eosin (H&E), luxol fast blue and cresyl fast violet (LFB/CFV) and anti-myelin oligodendrocyte glycoprotein, human leucocyte antigen-DR (HLA-DR) and 200 kDa neurofilament protein antibodies. Demyelinated areas were identified in 141 blocks, comprising both white matter (WMLs) and/or grey matter lesions. In total, 168 WMLs were identified, 22% of which were shadow plaques, 73% were partially remyelinated and only 5% were completely demyelinated. The average extent of lesion remyelination for all WMLs investigated was 47%. Increased density of HLA-DR(+) macrophages and microglia at the lesion border correlated significantly with more extensive remyelination. Results from this study of two patients with long standing disease suggest that remyelination in MS may be more extensive than previously thought.

Topical ethyl chloride fine spray. Does it have any antimicrobial activity?

AIM

The aim of this study was to assess whether ethyl chloride fine spray (Cryogesic) has antimicrobial activity.

MATERIAL AND METHODS

Blood agar plates supplemented with 5% horse blood were inoculated with five different organisms, coagulase-negative staphylococci (CNS), methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), Streptococcus pyogenes and Enterococcus faecalis. The plates were assessed for growth inhibition at 24 and 48 h by the microbiologist and compared with the non-sprayed control plates.

RESULTS

The model showed a highly significant (p<0.0001) reduction in bacterial count for the plates treated with fine ethyl chloride spray. The estimate of the percentage of bacteria remaining after spraying with ethyl chloride was 42.7%, with a 95% confidence interval of 35.9-50.9%. There was no evidence that the effect of ethyl chloride fine spray was different for the different organisms (p=0.49).

CONCLUSION

The use of ethyl chloride shows bacterial count reduction but the clinical implication of this needs to be determined. The authors postulate that any statistically significant reduction can only be helpful in reducing the infection rates. This coupled with the already proven local anaesthetic effects of ethyl chloride will make it an important tool for procedures like arthrocentesis and venepunctures.

How a neuropsychiatric brain bank should be run: a consensus paper of Brainnet Europe II

The development of new molecular and neurobiological methods, computer-assisted quantification techniques and neurobiological investigation methods which can be applied to the human brain, all have evoked an increased demand for post-mortem tissue in research. Psychiatric disorders are considered to be of neurobiological origin. Thus far, however, the etiology and pathophysiology of schizophrenia, depression and dementias are not well understood at the cellular and molecular level. The following will outline the consensus of the working group for neuropsychiatric brain banking organized in the Brainnet Europe II, on ethical guidelines for brain banking, clinical diagnostic criteria, the minimal clinical data set of retrospectively analyzed cases as well as neuropathological standard investigations to perform stageing for neurodegenerative disorders in brain tissue. We will list regions of interest for assessments in psychiatric disorder, propose a dissection scheme and describe preservation and storage conditions of tissue. These guidelines may be of value for future implementations of additional neuropsychiatric brain banks world-wide.

Astrophysical reaction rate for the neutron-generator reaction 13C(alpha,n)16O in asymptotic giant branch stars

The reaction 13C(alpha,n) is considered to be the main source of neutrons for the s process in asymptotic giant branch stars. At low energies, the cross section is dominated by the 1/2+ 6.356 MeV subthreshold resonance in (17)O whose contribution at stellar temperatures is uncertain by a factor of 10. In this work, we performed the most precise determination of the low-energy astrophysical S factor using the indirect asymptotic normalization (ANC) technique. The alpha-particle ANC for the subthreshold state has been measured using the sub-Coulomb alpha-transfer reaction ((6)Li,d). Using the determined ANC, we calculated S(0), which turns out to be an order of magnitude smaller than in the nuclear astrophysics compilation of reaction rates.

Disruption of neurofascin localization reveals early changes preceding demyelination and remyelination in multiple sclerosis

Saltatory conduction in the nervous system is enabled through the intimate association between the leading edge of the myelin sheath and the axonal membrane to demarcate the node of Ranvier. The 186 kDa neuron specific isoform of the adhesion molecule neurofascin (Nfasc186) is required for the clustering of voltage gated Na+ channels at the node, whilst the 155 kDa glial specific isoform (Nfasc155) is required for the assembly of correct paranodal junctions. In order to understand the relationship between these vital structures and how they are affected in multiple sclerosis we have examined the expression of Nfasc155 and Nfasc186 in areas of inflammation, demyelination and remyelination from post-mortem brains. Fourteen cases of neuropathologically confirmed multiple sclerosis (8 female and 6 male; post-mortem delay 7-24 h; age 37-77 years; and disease duration 15-40 years), comprising 20 tissue blocks with 32 demyelinating or remyelinating lesions, were used in this study. A significant early alteration in Nfasc155+ paranodal structures occurs within and adjacent to actively demyelinating white matter lesions that are associated with damaged axons. Shaker-type Kv1.2 channels, normally located distally to the paranode, overlapped with the disrupted Nfasc155+ structures. In the absence of Nfasc155, Kv1.2 channels abutted normally clustered Nfasc186+ nodes, indicating that complete disruption of the paranodal structure and movement of Kv1.2 channels precede alterations at the node itself. Within areas of partial remyelination, a number of atypical triple-Nfasc155+ structures were noted that may represent transient oligodendrocyte-axonal contacts during the process of myelin repair or aberrant interactions. Within shadow plaques discretely clustered Na+v, Nfasc186+ and Nfasc155+ domains indicated the restoration of normal nodal architecture. The alterations in oligodendrocyte Nfasc155 expression that accompany inflammation and demyelination suggest an ongoing disruption to the axonal-oligodendrocyte complex within newly forming as well as established lesions in multiple sclerosis, resulting in destruction of the Nfasc186+/Na+v nodal complex vital to successful fast neurotransmission in the CNS.

Nodal, paranodal and juxtaparanodal axonal proteins during demyelination and remyelination in multiple sclerosis

Saltatory conduction in myelinated fibres depends on the specific molecular organization of highly specialized axonal domains at the node of Ranvier, the paranodal and the juxtaparanodal regions. Voltage-gated sodium channels (Na(v)) have been shown to be deployed along the naked demyelinated axon in experimental models of CNS demyelination and in multiple sclerosis lesions. Little is known about aggregation of nodal, paranodal and juxtaparanodal constituents during the repair process. We analysed by immunohistochemistry on free-floating sections from multiple sclerosis brains the expression and distribution of nodal (Na(v) channels), paranodal (paranodin/Caspr) and juxtaparanodal (K(v) channels and Caspr2) molecules in demyelinated and remyelinated lesions. Whereas in demyelinated lesions, paranodal and juxtaparanodal proteins are diffusely distributed on denuded axons, the distribution of Na(v) channels is heterogeneous, with a diffuse immunoreactivity but also few broad Na(v) channel aggregates in all demyelinated lesions. In contrast to the demyelinated plaques, all remyelinated lesions are characterized by the detection of aggregates of Na(v) channels, paranodin/Caspr, K(v) channels and Caspr2. Our data suggest that these aggregates precede remyelination, and that Na(v) channel aggregation is the initial event, followed by aggregation of paranodal and then juxtaparanodal axonal proteins. Remyelination takes place in multiple sclerosis tissue but myelin repair is often incomplete, and the reasons for this remyelination deficit are many. We suggest that a defect of Na(v) channel aggregation might be involved in the remyelination failure in demyelinated lesions with spared axons and oligodendroglial cells.

Inactivation of West Nile virus, vaccinia virus and viral surrogates for relevant and emergent viral pathogens in plasma-derived products

Background and Objectives  Human plasma is the source of a wide variety of therapeutic proteins, yet it is also a potential source of viral contamination. Recent outbreaks of emergent viral pathogens, such as West Nile virus, and the use of live vaccinia virus as a vaccine have prompted a reassessment of the viral safety of plasma‐derived products. The purpose of this study was to evaluate the efficacy of current viral inactivation methods for West Nile and vaccinia viruses and to reassess the use of model viruses to predict inactivation of similar viral pathogens.

Materials and Methods  Virus‐spiked product intermediates were processed using a downscaled representation of various manufacturing procedures. Virus infectivity was measured before and after processing to determine virus inactivation.

Results  The results demonstrated effective inactivation of West Nile virus, vaccinia virus and a model virus, bovine viral diarrhoea virus, during pasteurization, solvent/detergent treatment and caprylate treatment. Caprylate provided rapid and effective inactivation of West Nile virus, vaccinia virus, duck hepatitis B virus and Sindbis virus. Inactivation of West Nile virus was similar to that of bovine viral diarrhoea virus.

Conclusions  This study demonstrates that procedures used to inactivate enveloped viruses in manufacturing processes can achieve inactivation of West Nile virus and vaccinia virus. In addition, the data support the use of model viruses to predict the inactivation of similar emergent viral pathogens.

Quality of Life in Patients Treated with First-Line Antiretroviral Therapy Containing Nevirapine And/Or Efavirenz

Objective

To assess whether differences in safety profiles between nevirapine (NVP) and efavirenz (EFV), as observed in the 2NN study, translated into differences in ‘health related quality of life’ (HRQoL).

Design

A sub-study of the 2NN study, with antiretro-viral-naive patients randomly allocated to NVP (once or twice daily), EFV or NVP+EFV, in addition to stavudine and lamivudine.

Methods

Comparing differences in changes of HRQoL over 48 weeks as measured with the Medical Outcomes Study HIV Health Survey (MOS-HIV) questionnaire, using analysis of variance.

Results

The 2NN study enrolled 1216 patients. No validated questionnaires were available for 244 patients, and 55 patients had no HRQoL data at all, leaving 917 patients eligible for this sub-study. A total of 471 (51%) had HRQoL measurements both at baseline and week 48. The majority (69%) of patients without HRQoL measurements did, however, complete the study. The change in the physical health score (PHS) was 3.9 for NVP, 3.4 for EFV and 2.4 for NVP+EFV ( P=0.712). For the mental health score (MHS) these values were 6.1, 7.0 and 3.9, respectively ( P=0.098). A baseline plasma HIV-1 RNA concentration (pVL) ≥100 000 copies/ml and a decline in pVL (per log10) were independently associated with an increase of PHS. An increase of MHS was only associated with pVL decline. Patients experiencing an adverse event during follow-up had a comparable change in PHS but a significantly smaller change in MHS, compared with those without an adverse event.

Conclusions

First-line ART containing NVP and/or EFV leads to an improvement in HRQoL. The gain in HRQoL was similar for NVP and EFV, but slightly lower for the combination of these drugs.

Multi-locus interactions predict risk for post-PTCA restenosis: an approach to the genetic analysis of common complex disease

The complexity of recognizing the potential contribution of a number of possible predictors of complex disorders is increasingly challenging with the application of large-scale single nucleotide polymorphism (SNP) typing. In the search for putative genetic factors predisposing to coronary artery restenosis following balloon angioplasty, we determined genotypes for 94 SNPs representing 62 candidate genes, in a prospectively assembled cohort of 342 cases and 437 controls. Using a customized coupled-logistic regression procedure accounting for both additive and interactive effects, we identified seven SNPs in seven genes that, together, showed a statistically significant association with restenosis incidence (P <0.0001), accounting for 11.6% of overall variance observed. Among them are candidate genes for cardiovascular pathophysiology (apolipoprotein-species and NOS), inflammatory response (TNF receptor and CD14), and cell-cycle control (p53 and p53-associated protein). Our results emphasize the need to account for complex multi-gene influences and interactions when assessing the molecular pathology of multifactorial medical entities.

Down-regulation of GAP-43 During Oligodendrocyte Development and Lack of Expression by Astrocytes In Vivo: Implications for Macroglial Differentiation

The discovery of molecular markers which are selectively expressed during the development of specific classes of rat central nervous system macroglia has greatly advanced our understanding of how these cells are related. In particular, it has been shown in tissue culture that oligodendrocytes and some astrocytes (type-2) may be derived from a common progenitor cell (O-2A progenitor). However, the existence of type-2 astrocytes in vivo has yet to be unequivocally established. Recently, it has been reported that the neural-specific growth-associated protein-43 (GAP-43, otherwise known as B-50, F1, pp46 and neuromodulin) may be expressed by cells of the O-2A lineage in vitro. We set out to examine the cellular specificity of GAP-43 in O-2A progenitors and their descendants in vitro and in vivo. Using a polyclonal antiserum against a GAP-43 fusion protein we have shown the presence of immunoreactive GAP-43 in the membranes of bipotential O-2A glial progenitor cells and type-2 astrocytes by Western blotting and immunocytochemistry of cells in culture. In contrast to previous studies, double labelling with mature oligodendrocyte markers showed that GAP-43 is down-regulated during oligodendrocyte differentiation in vitro. Immunohistochemical staining of sections of developing rat brain demonstrated the same developmental regulation of GAP-43, suggesting that oligodendrocytes only express GAP-43 at immature stages. In addition, normal and reactive astrocytes in tissue sections were not labelled with GAP-43.

Disturbed oligodendrocyte development and recovery from hypomyelination in a c-myc transgenic mouse mutant

The complexity of interactions underlying the elaboration of myelin has been extensively demonstrated. We provide evidence that signals promoting myelination are not confined to the normal developmental time window for myelination and persist well into adult life. The 2-50 mutant, described previously, carries a c-myc transgene regulated by a myelin basic protein promoter. This mutant is characterised by severe hypomyelination and abnormal oligodendrocytes in early life, followed by loss of the phenotype and normal longevity. We show that c-myc expression in early oligodendrocyte development results in a substantial reduction of cells of this lineage. However, apparent complete recovery, associated with loss of c-myc expression, axonal survival, and gradual myelin accumulation, is observed by 4 months of age. Thus, stimulation of myelination continues during adult life until normal myelin levels are established. We propose that this mutant may contribute to the characterisation of oligodendrocyte responses to myelinating signals.

The response of adult oligodendrocyte progenitors to demyelination in EAE

Cells with the phenotypic characteristics of oligodendrocyte progenitors (NG2+/PDGF alpha R+/O4+) are found throughout the adult mammalian CNS in numbers similar to microglia. They are a reactive glial cell population and respond to demyelination by increasing in number, thereby repopulating the lesion site with cells capable of differentiating into remyelinating oligodendrocytes. Direct evidence that they differentiate into remyelinating cells is missing, although this is the most likely scenario. Cells with the same phenotype are found in normal human CNS tissue and also in chronic MS lesions. Further studies on this intriguing cell type are necessary in order to understand the molecular signals involved in their reaction to injury, particularly in multiple sclerosis.

Aeolian dust in Colorado Plateau soils: nutrient inputs and recent change in source

Aeolian dust (windblown silt and clay) is an important component in arid-land ecosystems because it may contribute to soil formation and furnish essential nutrients. Few geologic surfaces, however, have been characterized with respect to dust-accumulation history and resultant nutrient enrichment. We have developed a combination of methods to identify the presence of aeolian dust in arid regions and to evaluate the roles of this dust in ecosystem processes. Unconsolidated sandy sediment on isolated surfaces in the Canyonlands region of the Colorado Plateau differs greatly in mineralogical and chemical composition from associated bedrock, mainly aeolian sandstone. Detrital magnetite in the surficial deposits produces moderately high values of magnetic susceptibility, but magnetite is absent in nearby bedrock. A component of the surficial deposits must be aeolian to account for the abundance of magnetite, which formed originally in far-distant igneous rocks. Particle-size analysis suggests that the aeolian dust component is typically as much as 20-30%. Dust inputs have enriched the sediments in many elements, including P, Mg, Na, K, and Mo, as well as Ca, at sites where bedrock lacks calcite cement. Soil-surface biologic crusts are effective dust traps that apparently record a change in dust sources over the past several decades. Some of the recently fallen dust may result from human disturbance of land surfaces that are far from the Canyonlands, such as the Mojave Desert. Some land-use practices in the study area have the potential to deplete soil fertility by means of wind-erosion removal of aeolian silt.

Galactose metabolism in normal human lymphoblasts studied by (1)H, (13)C and (31)P NMR spectroscopy of extracts

The development of tools to follow and quantitate the fate of galactose in mammalian cells is crucial to the study and understanding of the inherited disorders of galactose metabolism. In this study we incubated normal human lymphoblasts with 1- or 2-(13)C galactose for 2.5 or 5 h and prepared TCA extracts of the cells. The various galactose metabolites were identified and quantified using a combination of proton, carbon and phosphorus NMR spectra. Galactose-1-phosphate (gal-1P), uridine diphosphogalactose, uridine diphosphoglucose and galactitol were present in the extracts. Average levels for gal-1P were around 10 nmol/mg protein and for uridine diphosphoglucose, uridine diphosphogalactose and galactitol in the range of 0.5-2 nmol/mg protein. Galactonate was never found in any conditions. Percentage labeling could be estimated for gal-1P and for the ribose carbons of AMP. The labeling agrees with a conversion of galactose to glucose through the Leloir pathway.

Characterization of a novel D1S80 pseudoallele

During a D1S80 population study conducted for databasing purposes in the New York City Ashkenazi Jewish population, eight out of 96 samples were typed with a band corresponding to the position of a #15 allele. In seven of the eight samples, three bands appeared. Further investigation was needed to explain the high frequency of an allele considered so rare that it is not included in the commercially provided allelic ladder. After extraction of the putative D1S80 15-repeat amplicon band from the 6% polyacrylamide genotyping gel, the amplicon bands were reamplified with D1S80 primers. After retyping as putative 15 alleles, these samples underwent Southern hybridization with a D1S80 locus-specific probe followed by DNA sequence analysis. Sequence analysis revealed that these bands did not arise from true D1S80 15 alleles. However, the PCR product was of a size that fell within the allelic ladder region corresponding to the 15 band and contained end sequences with strong homology to the D1S80 primers. An alignment search of the sequenced product revealed that a portion of the amplicons contained 72% identity to a known gene. These results emphasize the importance of sequencing analysis when questions arise about the authenticity of an allele.

Galactose metabolism in mice with galactose-1-phosphate uridyltransferase deficiency: sucklings and 7-week-old animals fed a high-galactose diet

Mice deficient in galactose-1-phosphate uridyltransferase (GALT) demonstrate abnormal galactose metabolism but no obvious clinical phenotype. To further dissect the pathways of galactose metabolism in these animals, galactose oxidation and metabolite levels were studied in 16-day-old sucklings and the effect of a 4 week prior exposure to a 40% glucose or 40% galactose diet was determined in 7-week-old mice. Suckling GALT-deficient (G/G) mice slowly oxidized [1-14C]galactose to 14CO2, 4.0% of the dose when fed and 7.9% when fasted compared to normal animals 38.3 and 36.4% in 4 h, respectively. Plasma of G/G sucklings contained 11.1 mM galactose and erythrocyte galactose 1-phosphate levels were 28.2 and 31.9 mg/dl packed cells. Galactose, galactitol, galactonate, and galactose 1-phosphate were found in G/G suckling mouse tissues. The tissue galactose concentrations were 10% or less of that in plasma, suggesting that there was limited cellular entry of galactose. In 7-week-old fasted mice with 4 weeks prior exposure to glucose or galactose-containing diet, 4-h oxidation was 12.9 and 15.0% of the administered radiolabeled galactose, respectively. Normal animals oxidized 33.9 and 37.9% of the dose when fed the same diets, respectively. The ability of G/G mice to oxidize galactose in the absence of GALT activity suggests the presence of alternate metabolic pathways for galactose disposition. G/G mice fed the galactose-free 40% glucose diet had erythrocyte galactose 1-phosphate levels ranging from 6.4 to 17.7 mg/dl packed cells and detectable galactose and galactose metabolites in tissues, suggesting that these animals endogenously produced galactose. The plasma of 40% galactose-fed G/G mice contained 9.1 mM galactose with red blood cell galactose 1-phosphate averaging 43.6 mg/dl. Tissues of these animals also contained high levels of galactose and galactose 1-phosphate. Liver contained over 4 micromol/g galactonate but little galactitol. Despite the elevated galactose and galactose 1-phosphate, the animals tolerated the high-galactose diet and were indistinguishable from normal animals, exhibiting no manifestations of galactose toxicity seen in human GALT-deficient galactosemia. The data suggest that high galactose 1-phosphate levels do not cause galactose toxicity and that high galactitol in combination with galactose 1-phosphate may be a prerequisite. Absence of GALT appears necessary but insufficient to produce human galactosemic phenotype.

Evidence for alternate galactose oxidation in a patient with deletion of the galactose-1-phosphate uridyltransferase gene

The persistent, dietary-independent elevation of galactose metabolites in patients with galactose-1-phosphate uridyltransferase (GALT) deficiency is probably secondary to de novo synthesis of galactose. Relatively constant steady-state levels of galactose metabolites in patients also suggest that non-GALT metabolic pathways must function to dispose of the galactose synthesized each day. The discovery of a patient with a rare deletion of the GALT gene provided a unique opportunity to examine the availability of any alternate galactose oxidative capacity both in vivo and in vitro. Utilizing genomic DNA from the patient, Southern blot data demonstrated that 10 of the 11 GALT exons were homozygously deleted. By measurement of 13CO2 in expired air for up to 24 h after an oral bolus of [1-13C]galactose, it was demonstrated that 17% of the galactose was metabolized, a value comparable to the 3-h elimination rate in a control subject. Furthermore, lymphoblasts prepared from the patient could also convert [1-14C]galactose to 14CO2. This unique study provides the first unambiguous evidence that another pathway exists in man that can be responsible for galactose disposal. Further knowledge of this alternate galactose oxidative route and its regulation may aid in formulating new strategies for the treatment of galactosemia.

Expression of QKI proteins and MAP1B identifies actively myelinating oligodendrocytes in adult rat brain

We have studied developing oligodendrocytes in tissue sections as they initiate myelination and have found that the transition from premyelinating oligodendrocytes into myelin-bearing cells is accompanied by a dramatic upregulation in expression of the RNA binding QKI proteins. We show that in mature oligodendrocytes in culture, the localization of cytoplasmic QKI isoforms requires an intact cytoskeleton. Together with previous observations, this indicates that cytoplasmic QKI proteins facilitate movement of mRNAs to myelin via the cytoskeleton. In the adult rat brain, we found that a subset of oligodendrocytes displays characteristics of actively myelinating cells seen during development, i.e., connections to myelin sheaths and elevated levels of QKI proteins and also MAP1B. These observations suggest that instead of merely maintaining myelin, oligodendrocytes in the normal adult CNS are capable of responding to demands for new myelin sheaths. This has important implications for the prospect of repair of myelin in demyelinating conditions such as multiple sclerosis.

Respiratory responses of normal and vestibular defective human subjects to rotation in the yaw and pitch planes

We evaluated the contribution of the semicircular canals to autonomic responses to rotation in 12 normal subjects and three labyrinthine defective patients. Respiration, heart rate, arterial blood pressure and blood flow in the finger were recorded during 60 degrees /s steps of constant velocity rotation. Rotation was performed in the dark about a vertical axis: (I) with head upright for yaw stimulation of horizontal canals; (II) head tilted chin down and rotated laterally to stimulate the vertical canals in both face-forwards and backwards directions. In normal subjects, rotation in the pitch plane elicited an increase in respiratory frequency due to a shortening of the time for expiration, whilst patients had inconsistent responses. We conclude that vertical semicircular canal activity exerts a regulatory drive on respiration in human subjects.

The oligodendrocyte precursor cell in health and disease

Adult oligodendrocyte precursor cells (OPCs) make up around 5-8% of the glial cell population in the CNS. Their function in the undamaged CNS is largely unknown, but their processes are in contact with nodes of Ranvier and synapses, suggesting a regulatory role at these structures. The cells divide slowly, and constitute approximately 70% of cells labelled following a pulse injection of bromodeoxyuridine. In the injured CNS the cells form a reactive glial population that undergoes hypertrophy and mitosis, probably driven by a variety of growth factors and cytokines. In response to demyelination they divide and are thought to differentiate to provide new oligodendrocytes to replace those that have been lost. However, remyelination fails during the later stages of multiple sclerosis, and it is not clear whether this is as a result of a depletion of adult OPCs, inhibition within the glial scar, or damage to the axons that prevents myelination. Adult OPCs are also activated and proliferate following other forms of CNS damage, such as mechanical injury, excitotoxicity and viral infection. The cells produce several of the chondroitin sulphate proteoglycans that might inhibit axon regeneration.

Effect of community-based interventions on high-risk drinking and alcohol-related injuries

CONTEXT

High-risk alcohol consumption patterns, such as binge drinking and drinking before driving, and underage drinking may be linked to traffic crashes and violent assaults in community settings.

OBJECTIVES

To determine the effect of community-based environmental interventions in reducing the rate of high-risk drinking and alcohol-related motor vehicle injuries and assaults.

DESIGN AND SETTING

A longitudinal multiple time series of 3 matched intervention communities (northern California, southern California, and South Carolina) conducted from April 1992 to December 1996. Outcomes were assessed by 120 general population telephone surveys per month of randomly selected individuals in the intervention and comparison sites, traffic data on motor vehicle crashes, and emergency department surveys in 1 intervention-comparison pair and 1 additional intervention site.

INTERVENTIONS

Mobilize the community; encourage responsible beverage service; reduce underage drinking by limiting access to alcohol; increase local enforcement of drinking and driving laws; and limit access to alcohol by using zoning.

MAIN OUTCOME MEASURES

Self-reported alcohol consumption and driving after drinking; rates of alcohol-related crashes and assault injuries observed in emergency departments and admitted to hospitals.

RESULTS

Population surveys revealed that the self-reported amount of alcohol consumed per drinking occasion declined 6% from 1.37 to 1. 29 drinks. Self-reported rate of "having had too much to drink" declined 49% from 0.43 to 0.22 times per 6-month period. Self-reported driving when "over the legal limit" was 51% lower (0. 77 vs 0.38 times) per 6-month period in the intervention communities relative to the comparison communities. Traffic data revealed that, in the intervention vs comparison communities, nighttime injury crashes declined by 10% and crashes in which the driver had been drinking declined by 6%. Assault injuries observed in emergency departments declined by 43% in the intervention communities vs the comparison communities, and all hospitalized assault injuries declined by 2%.

CONCLUSION

A coordinated, comprehensive, community-based intervention can reduce high-risk alcohol consumption and alcohol-related injuries resulting from motor vehicle crashes and assaults. JAMA. 2000;284:2341-2347.

Detection of sequence variation in the HVII region of the human mitochondrial genome in 689 individuals using immobilized sequence-specific oligonucleotide probes

We have developed a rapid, immobilized probe-based assay for the detection of sequence variation in the hypervariable segment II (HVII) of the mitochondrial DNA (mtDNA) control region. Using a panel of 17 sequence-specific oligonucleotide (SSO) probes immobilized on nylon membrane strips, we typed 689 individuals from four population groups. The genetic diversity value for each population was calculated from the frequency data, and the frequencies of distinct "mitotypes" in each group were determined. We performed DNA sequence analysis of 129 samples to characterize the sequences associated with "blanks" (absence of probe signals) and weak probe signals. Out of 689 samples, we observed five heteroplasmic samples (excluding the variable C-stretch beginning at position 303) using the immobilized SSO probe panel. The SSO probe strips were used for the analysis of shed hairs and bloodstains from several criminal cases in Sweden, one of which is described here. We conclude that this mtDNA typing system is useful for human identification and significantly decreases casework turnaround time.