Extrapyramidal plasticity predicts recovery after spinal cord injury.

Spinal cord injury (SCI) leads to wide-spread neurodegeneration across the neuroaxis. We explored trajectories of surface morphology, demyelination and iron concentration within the basal ganglia-thalamic circuit over 2 years post-SCI. This allowed us to explore the predictive value of neuroimaging biomarkers and determine their suitability as surrogate markers for interventional trials. Changes in markers of surface morphology, myelin and iron concentration of the basal ganglia and thalamus were estimated from 182 MRI datasets acquired in 17 SCI patients and 21 healthy controls at baseline (1-month post injury for patients), after 3, 6, 12, and 24 months. Using regression models, we investigated group difference in linear and non-linear trajectories of these markers. Baseline quantitative MRI parameters were used to predict 24-month clinical outcome. Surface area contracted in the motor (i.e. lower extremity) and pulvinar thalamus, and striatum; and expanded in the motor thalamus and striatum in patients compared to controls over 2-years. In parallel, myelin-sensitive markers decreased in the thalamus, striatum, and globus pallidus, while iron-sensitive markers decreased within the left caudate. Baseline surface area expansions within the striatum (i.e. motor caudate) predicted better lower extremity motor score at 2-years. Extensive extrapyramidal neurodegenerative and reorganizational changes across the basal ganglia-thalamic circuitry occur early after SCI and progress over time; their magnitude being predictive of functional recovery. These results demonstrate a potential role of extrapyramidal plasticity during functional recovery after SCI.

Long-term effects of a maternal high-fat: high-fructose diet on offspring growth and metabolism and impact of maternal taurine supplementation.

OBJECTIVE: Maternal obesity is associated with obesity and metabolic disorders in offspring. However, there remains a paucity of data on strategies to reverse the effects of maternal obesity on maternal and offspring health. With maternal undernutrition, taurine supplementation improves outcomes in offspring mediated in part via improved glucose-insulin homeostasis. The efficacy of taurine supplementation in the setting of maternal obesity on health and well-being of offspring is unknown. We examined the effects of taurine supplementation on outcomes related to growth and metabolism in offspring in a rat model of maternal obesity. DESIGN: Wistar rats were randomised to: 1) control diet during pregnancy and lactation (CON); 2) CON with 1.5% taurine in drinking water (CT); 3) maternal obesogenic diet (MO); or 4) MO with taurine (MOT). Offspring were weaned onto the control diet for the remainder of the study. RESULTS: At day 150, offspring body weights and adipose tissue weights were increased in MO groups compared to CON. Adipose tissue weights were reduced in MOT versus MO males but not females. Plasma fasting leptin and insulin were increased in MO offspring groups but were not altered by maternal taurine supplementation. Plasma homocysteine concentrations were reduced in all maternal taurine-supplemented offspring groups. There were significant interactions across maternal diet, taurine supplementation and sex for response to an oral glucose tolerance test , a high-fat dietary preference test and pubertal onset in offspring. CONCLUSIONS: These results demonstrate that maternal taurine supplementation can partially ameliorate adverse developmental programming effects in offspring in a sex-specific manner.

Optimizing empiric therapy for Gram-negative bloodstream infections in children.

Antimicrobial stewardship can be challenging in children with bloodstream infections (BSIs) caused by Gram-negative bacilli (GNB). This retrospective cohort study explored how data elements in the electronic health record could potentially optimize empiric antibiotic therapy for BSIs caused by GNB, via the construction of customized antibiograms for categorical GNB infections and identification of opportunities to minimize organism-drug mismatch and decrease time to effective therapy. Our results suggest potential strategies that could be implemented at key decision points in prescribing at initiation, modification, and targeting of therapy.

The effect of crack cocaine addiction and age on the microstructure and morphology of the human striatum and thalamus using shape analysis and fast diffusion kurtosis imaging.

The striatum and thalamus are subcortical structures intimately involved in addiction. The morphology and microstructure of these have been studied in murine models of cocaine addiction (CA), showing an effect of drug use, but also chronological age in morphology. Human studies using non-invasive magnetic resonance imaging (MRI) have shown inconsistencies in volume changes, and have also shown an age effect. In this exploratory study, we used MRI-based volumetric and novel shape analysis, as well as a novel fast diffusion kurtosis imaging sequence to study the morphology and microstructure of striatum and thalamus in crack CA compared to matched healthy controls (HCs), while investigating the effect of age and years of cocaine consumption. We did not find significant differences in volume and mean kurtosis (MKT) between groups. However, we found significant contraction of nucleus accumbens in CA compared to HCs. We also found significant age-related changes in volume and MKT of CA in striatum and thalamus that are different to those seen in normal aging. Interestingly, we found different effects and contributions of age and years of consumption in volume, displacement and MKT changes, suggesting that each measure provides different but complementing information about morphological brain changes, and that not all changes are related to the toxicity or the addiction to the drug. Our findings suggest that the use of finer methods and sequences provides complementing information about morphological and microstructural changes in CA, and that brain alterations in CA are related cocaine use and age differently.

An investigation into the inhibitory function of serotonin in diffuse noxious inhibitory controls in the neuropathic rat.

BACKGROUND: Following neuropathy α2-adrenoceptor-mediated diffuse noxious inhibitory controls (DNIC), whereby a noxious conditioning stimulus inhibits the activity of spinal wide dynamic range (WDR) neurons, are abolished, and spinal 5-HT7 receptor densities are increased. Here, we manipulate spinal 5-HT content in spinal nerve ligated (SNL) animals and investigate which 5-HT receptor mediated actions predominate. METHODS: Using in vivo electrophysiology we recorded WDR neuronal responses to von frey filaments applied to the hind paw before, and concurrent to, a noxious ear pinch (the conditioning stimulus) in isoflurane-anaesthetised rats. The expression of DNIC was quantified as a reduction in WDR neuronal firing in the presence of conditioning stimulus and was investigated in SNL rats following spinal application of (1) selective serotonin reuptake inhibitors (SSRIs) citalopram or fluoxetine, or dual application of (2) SSRI plus 5-HT7 receptor antagonist SB269970, or (3) SSRI plus α2 adrenoceptor antagonist atipamezole. RESULTS: DNIC were revealed in SNL animals following spinal application of SSRI, but this effect was abolished upon joint application of SSRI plus SB269970 or atipamezole. CONCLUSIONS: We propose that in SNL animals the inhibitory actions (quantified as the presence of DNIC) of excess spinal 5-HT (presumed present following application of SSRI) were mediated via 5-HT7 receptors. The anti-nociception depends upon an underlying tonic noradrenergic inhibitory tone via the α2-adrenoceptor. SIGNIFICANCE: Following neuropathy enhanced spinal serotonin availability switches the predominant spinal 5-HT receptor-mediated actions but also alters noradrenergic signalling. We highlight the therapeutic complexity of SSRIs and monoamine modulators for the treatment of neuropathic pain.

Electrophysiological evidence for voltage-gated calcium channel 2 (Cav2) modulation of mechano- and thermosensitive spinal neuronal responses in a rat model of osteoarthritis.

Osteoarthritis (OA) remains one of the greatest healthcare burdens in western society, with chronic debilitating pain-dominating clinical presentation yet therapeutic strategies are inadequate in many patients. Development of better analgesics is contingent on improved understanding of the molecular mechanisms mediating OA pain. Voltage-gated calcium channels 2.2 (Cav2.2) play a critical role in spinal nociceptive transmission, therefore blocking Cav2.2 activity represents an attractive opportunity for OA pain treatment, but the only available licensed Cav2.2 antagonist ziconitide (PrilatTM) is of limited use. TROX-1 is an orally available, use dependent and state-selective Cav2 antagonist, exerting its analgesic effect primarily via Cav2.2 blockade, with an improved therapeutic window compared with ziconitide. Using a rat model of monosodium iodoacetate (MIA), 2 mg, induced OA we used in vivo electrophysiology to assess the effects of spinal or systemic administration of TROX-1 on the evoked activity of wide dynamic range spinal dorsal horn neurons in response to electrical, natural mechanical (dynamic brush and von Frey 2, 8, 26 and 6 g) and thermal (40, 45 and 45 °C) stimuli applied to the peripheral receptive field. MIA injection into the knee joint resulted in mechanical hypersensitivity of the ipsilateral hind paw and weight-bearing asymmetry. Spinal administration of TROX-1 (0.1 and 1 µg/50 µl) produced a significant dose-related inhibition of dynamic brush, mechanical (von Frey filament (vF) 8, 26 and 60 g) and noxious thermal-(45 and 48 °C) evoked neuronal responses in MIA rats only. Systemic administration of TROX-1 produced a significant inhibition of the mechanical-(vF 8, 26 and 60 g) evoked neuronal responses in MIA rats. TROX-1 did not produce any significant effect on any neuronal measure in Sham controls. Our in vivo electrophysiological results demonstrate a pathological state-dependent effect of TROX-1, which suggests an increased functional role of Cav2, likely Cav2.2, channels in mediating OA pain.

Toxicity and bioaccumulation potential of Cr (VI) and Hg (II) on differential concentration by Eichhornia crassipes in hydroponic culture.

In this work, the phytoremediation of Cr (VI) and Hg (II) ion from water by an aquatic plant Eichhornia crassipes has been studied. Plants were cultured in a double distillated water with modified Hoagland's nutrient solution at pH 6.8 supplemented with 0, 0.75, 1.50, 2.50, and 4 mg Cr/L as potassium dichromate (K(2)Cr(2)O(7)) and 0, 5, 10, 15, and 20 mg Hg/L as mercuric chloride (HgCl(2)). They were separately harvested after 3, 6 and 9 days. Plants treated with 4 mg/L of Cr (VI) accumulated the highest concentration of metal in roots (1.22 mg/g, dry weight) and shoots (0.24 mg/g, dry weight) after 9 days; while those treated with 20 mg/L of Hg (II) accumulated the highest concentration of metal in roots (4.22 mg/g, dry weight) and shoots (2.43 mg/g, dry weight) after 9 days. Eichhornia crassipes biomass was characterised using AAS, SEM and FTIR. The accumulation and relative growth of metal ions at different concentrations of chromium and mercury solution significantly increased (P<0.05) with the passage of time. The maximum values of bio-concentration factor (BCF) for Cr (VI) and Hg (II) were found to be 413.33 and 502.40 L/kg respectively.

Mangifera indica (mango).

Mangifera indica, commonly used herb in ayurvedic medicine. Although review articles on this plant are already published, but this review article is presented to compile all the updated information on its phytochemical and pharmacological activities, which were performed widely by different methods. Studies indicate mango possesses antidiabetic, anti-oxidant, anti-viral, cardiotonic, hypotensive, anti-inflammatory properties. Various effects like antibacterial, anti fungal, anthelmintic, anti parasitic, anti tumor, anti HIV, antibone resorption, antispasmodic, antipyretic, antidiarrhoeal, antiallergic, immunomodulation, hypolipidemic, anti microbial, hepatoprotective, gastroprotective have also been studied. These studies are very encouraging and indicate this herb should be studied more extensively to confirm these results and reveal other potential therapeutic effects. Clinical trials using mango for a variety of conditions should also be conducted.

Polymeric black tea polyphenols inhibit mouse skin chemical carcinogenesis by decreasing cell proliferation.

OBJECTIVES: The aim of this study was to investigate the antitumour promoting effects and possible mechanisms of action of the most abundant polymeric black tea polyphenols (PBPs 1-5) or thearubigins, in vivo. MATERIALS AND METHODS: Effect of PBP pre-treatments on 12-O-tetradecanoylphorbol-13-acetate (TPA) promoted skin papillomas was studied in 7,12-dimethylbenz(a)anthracene initiated mice over 40 weeks. Cell proliferation and apoptosis, in epidermis of the skin, were measured using appropriate immunohistochemical staining. Mitogen-activated protein kinase signalling studies were conducted with Western blot analysis at 10, 20, 30 and 40 weeks of promotion. RESULTS: Pre-treatments with PBP fractions differentially altered latency, multiplicity and incidence of skin papillomas as compared to TPA treatments thereby exhibiting antipromoting effects. Most PBP fractions decreased TPA-induced cell proliferation by decreasing activation of signalling kinases (c-Jun N-terminal protein kinase, extracellular signal-regulated protein kinase, p38 protein kinase and Akt), transcription factors (activator protein-1 and nuclear factor kappa B) and inflammatory protein (cyclooxygenase 2). TPA-induced epidermal cell apoptosis was also decreased by pre-treatment with most PBP fractions. Higher levels of p53 and p21 in skin cells pre-treated with PBP fractions followed by TPA treatment as compared to only TPA-treated animals suggested possible activation of a cell cycle checkpoint. CONCLUSIONS: PBP-2 was observed to be the most potent polymeric polyphenol fraction and PBP-4 and PBP-5 showed only marginal activity, whereas PBP-1 and PBP-3 displayed intermediate efficacies. In conclusion, the protective effects of PBP fractions could be attributed to inhibition of TPA-induced cellular proliferation.

Leprosy control activities in India: integration into general health system.

Integration of leprosy control into the general health system is an essential element of a leprosy elimination strategy. In India, the process has been undertaken with the assistance of World Bank in a phased manner. In the first phase (2001-2002), 24 low/moderately endemic provinces for leprosy were targeted. Operational research was undertaken in these low/moderate endemic provinces to assess the progress of integration of leprosy control in general health system using defined categories, viz. structural integration, training status, availability of MDT and recording/reporting of cases. Selection of nine provinces, 18 districts, 86 health facilities and 108 sub-centres was performed using multistage stratified random sampling technique. Data were collected by interviewing GHS/vertical staff, scrutiny of records and spot checking of MDT stock by Health officers of three leprosy institutions of the Government of India. The result showed that district leprosy nuclei had formed in 16 of 18 districts. In 56% of health facilities vertical staff were redeployed for delivering general health care. Forty-five percent of medical officers, 71% of health supervisors and 75% of multipurpose workers were trained in leprosy. MDT treatment was available in >80% of health facilities. In only 2% of health facilities 3 months MDT stock of all types was present. Forty-four percent of sub-centres were delivering subsequent doses (second dose onward) of MDT. Reporting through a simplified information system was universal. This study emphasizes the need for reorientation training of Medical Officers, better MDT stock management and decentralized management of cases up to sub-centre level.

Inter-state variations in integration of leprosy services into general health system in low/ moderately endemic states of India.

The objective of the study was to analyse inter-state variations in integration of leprosy services into the general health system, covering broad categories of structure integration, training of health functionaries, availability of MDT services and record maintenance, in 24 low/moderately endemic states. Multi-stage random sampling technique was used to select 9 states, 86 health facilities (including district hospitals, community health centres, primary health centres) and 108 sub-centres. Information from each level was collected on a pre-tested form by officers of three leprosy institutions of the Government of India. The results showed wide inter-state variations on each aspect. Redeployment of vertical staff was complete (100%) in Tamil Nadu and Tripura. Assam reported a higher level of training (97%) of medical officers in leprosy. Training of health supervisors and multipurpose workers was better than that of medical officers in most of the states. Tripura reported negligible training of all the health functionaries because of specific local problems. In Assam, Maharashtra and Sikkim, all the urban and rural health facilities were providing MDT. Three months' stock of all types of MDT blister packs was available only in one health facility in Andhra Pradesh and in Goa. Assam and Haryana had lower availability of MDT stocks. In Assam and Maharashtra, medical officers in all health facilities were diagnosing and treating leprosy cases, as compared with Himachal Pradesh where the value was 30%. Involvement of sub-centres in MDT delivery was more at 92% and 100% in Tamil Nadu and Maharashtra respectively in comparison to none in Himachal Pradesh and Tripura. Use of the Simplified Information System (SIS) 2002 guidelines and formats was universal. However, lower involvement of GHS staff in recording and reporting was noted in Assam (0%), Andhra Pradesh (10% and 30%). The study emphasized the need for further tailor-made follow-up studies to suit local problems.

Emergence of quinolone resistance among viridans group streptococci isolated from the oropharynx of neutropenic peripheral blood stem cell transplant patients receiving quinolone antimicrobial prophylaxis.

In neutropenic patients receiving quinolone prophylaxis, bacteremia with viridans group streptococci resistant to quinolones is a known complication. The frequency of occurrence of quinolone-resistant organisms colonizing the oropharynx during antibacterial prophylaxis with a quinolone is not well defined. In 48 patients undergoing hematopoietic stem cell transplantation, the prevalence of quinolone resistance in viridans group streptococci colonizing the oropharynx before and during antibacterial prophylaxis with gatifloxacin or moxifloxacin (most with concomitant penicillin) was determined. For quinolone-resistant isolates, mutations in the genes gyrA and parC, which confer resistance to quinolones, were analyzed. Seventy-four isolates before and 27 isolates during quinolone use were recovered from patients' oropharynxes. The numbers of susceptible isolates recovered before versus during quinolone use were as follows: 52 (70%) versus three (11%) for ciprofloxacin, 66 (89%) versus eight (30%) for levofloxacin, 66 (89%) versus ten (37%) for gatifloxacin, and 67 (91%) versus 11 (41%) for moxifloxacin (p<0.0001). Mutations in gyrA and/or parC were detected in quinolone-resistant isolates. Quinolone-resistant viridans group streptococci are frequently found in the oropharynx of neutropenic patients after a brief (median, 8 days) exposure to gatifloxacin or moxifloxacin.

Integration of leprosy control into general health care system: observations from a state with low endemicity.

The study was undertaken as part of operational research to assess the level of integration of leprosy services into general health care system in 24 low or moderately endemic states/union territories by the Ministry of Health and Family Welfare, Government of India. Himachal Pradesh was one of the nine randomly selected states for the study. Out of the 12 districts in the State, 2 were selected randomly for the study. In each of the selected districts, 8 health facilities (that included a district hospital, an urban hospital/urban health centre, an Employees' State Insurance Hospital, a community health centre and a primary health centre) and 9 sub-centres were surveyed. Selection was done randomly at each stage. Data were collected on training in leprosy of general health care staff, availability of drugs for MDT in the system and maintenance of leprosy records by the staff of the system. The study showed mixed results. About half (53.2%) of the existing medical officers, 83.9% of health supervisors and 96.8% of multi-purpose workers were trained in leprosy. But only 31.3% of medical officers were able to diagnose leprosy and most of them were relying on vertical staff and skin specialists for confirmation. MDT services were provided by 20% of rural and 66.7% of urban health facilities that were acting as treatment centres. None of the health facilities had 3 months' stock of all types of blister packs, as per the guidelines of the Government of India. None of the sub-centres was involved in MDT delivery. However, reporting as per SIS formats was universal. The study emphasized the need for training and better management of MDT drug stock.

A list of device-specific thresholds for the clinical interpretation of peripheral x-ray absorptiometry examinations.

The UK National Osteoporosis Society (NOS) has recently issued new guidelines on the use of peripheral x-ray absorptiometry (pDXA) devices in managing osteoporosis. The NOS guidelines recommend a triage approach in which patients' bone mineral density (BMD) measurements are interpreted using upper and lower thresholds specific to each type of pDXA device. The thresholds are defined so that patients with osteoporosis at the hip or spine are identified with 90% sensitivity and 90% specificity. Patients with a pDXA result below the lower threshold are likely to have osteoporosis at the hip or spine, patients with a result above the upper threshold are unlikely to have osteoporosis, while those between the two thresholds require a hip and spine BMD examination for a definitive diagnosis. This report presents data from a multicenter study to establish the triage thresholds for a range of pDXA devices in use in the UK. The subjects were white female patients aged 55-70 years who met the normal referral criteria for a BMD examination. For each device, at least 70 women with osteoporosis at the hip or spine and 70 women without osteoporosis were enrolled. All women had hip and spine BMD measurements using axial DXA systems that were interpreted using the National Health and Nutrition Examination Survey (NHANES) reference range for the hip and the manufacturers' reference ranges for the spine. Data are presented for five different devices: the Osteometer DTX-200 (forearm BMD), the Schick AccuDEXA (hand BMD), the GE Lunar PIXI (heel BMD), the Alara MetriScan (hand BMD), and the Demetech Calscan (heel BMD). The clinical measurements were supplemented by theoretical modeling to estimate the age dependence of the triage thresholds and the effect of the correlation coefficient between pDXA and axial BMD on the percentage of women referred for an axial BMD examination. In summary, this study provides thresholds for implementing the new NOS guidelines for managing osteoporosis using pDXA devices. The figures reported apply to postmenopausal white women aged 55-70 years who meet the conventional criteria for a BMD examination. The results confirm that the thresholds are specific to each type of pDXA device and that the NOS triage algorithm requires 40% of women to have an axial DXA examination.

Oxidative stress is the master operator of drug and chemically-induced programmed and unprogrammed cell death: Implications of natural antioxidants in vivo.

ROS, RNS, BRIs and ROS-RNS hybrids are produced during drug or chemical metabolism in vivo. These reactive species are instrumental to the culmination of cellular oxidative stress (OS). OS, once turned on, does not spare any vital intracellular macromolecule, such as glutathione, DNA, RNA, proteins, enzymes, lipids and ATP. Since concentration gradients of such components are very delicately balanced for normal cellular functioning, a gross perturbation leads to cell injury and cell death. Abundant evidence now suggests that intracellular antioxidants keep OS in check and maintain homeostasis. Our laboratory has focused on the role of OS in orchestrating various forms of cell death during drug and chemically-induced target organ toxicity and their counteraction by various natural or synthetic antioxidants in in vivo models. Despite complexity of the in vivo models, results show that metabolism of xenobiotics are invariably associated with different degrees of OS and natural antioxidants such as grape seed extract, bitter melon extract (Momordica charantia) and N-acetylcysteine (NAC) which were very effective in counteracting organ toxicities by minimizing events linked to OS (lipid peroxidation and total glutathione), and CAD-mediated DNA fragmentation. Phytoextract exposure rescued cells from toxic assaults, protected genomic integrity, and minimized apoptotic, necrotic and apocrotic (oncotic necrosis) cell deaths. Pre-exposure mode was more effective than post-exposure route. Overall scenario suggests that OS may have been the prime modulator of death and/or survival programs, whereas, antioxidants may have imparted a dual role in either erasing death signals or reviving survival signals, and a combination of antioxidants may be more beneficial than a single entity to influence a number of intracellular events operating simultaneously to neutralize chaotic toxicological consequences.

Regulatory potential of fever-range whole body hyperthermia on Langerhans cells and lymphocytes in an antigen-dependent cellular immune response.

The febrile response is one of the most common features of infection and inflammation. However, temperature is rarely a variable in experimental immunological investigations. To determine whether the thermal microenvironment has any immunoregulatory potential in an Ag-dependent response, we applied a mild fever-range whole body hyperthermia (FR-WBH) protocol to BALB/c mice experiencing the contact hypersensitivity (CHS) reaction. We observed that the timing of this FR-WBH treatment relative to the different phases of the CHS response was crucial to the outcome. FR-WBH treatment before sensitization with a 0.5% FITC solution resulted in a depressed CHS response. This appears to be due to direct effects of FR-WBH on epidermal Langerhans cell trafficking to the draining lymph nodes. In contrast, application of FR-WBH directly after application of the elicitation dose of FITC solution resulted in an enhanced reaction. This result correlates with increased homing of lymphocytes to the site of elicitation. Overall, these data have important implications regarding the role of thermal changes experienced during infection and the clinical use of FR-WBH relative to immunotherapeutic strategies.

The effect of season and vitamin D supplementation on bone mineral density in healthy women: a double-masked crossover study.

Vitamin D status is known to be an important determinant of bone mineral density (BMD). There is a significant seasonal variation in serum vitamin D, and some studies have reported an associated seasonal variation in BMD. The present study was devised to investigate whether a seasonal variation in BMD could be detected in healthy normal subjects, along with associated variations in serum parathyroid hormone (PTH), intestinal calcium absorption and biochemical markers of bone turnover. A second aim was to investigate whether, if such variations were identified, they could be suppressed by vitamin D supplementation. The subjects were 70 healthy female volunteers (mean age 47.2 years, range 24-70 years) recruited into a double-masked crossover study and followed over 2 years. During the first year 35 subjects received a daily oral supplement containing 800 IU (20 micrograms) cholecalciferol (group 1) and 35 subjects received a placebo preparation (group 2). During the second year the treatment each group received was reversed. Lumbar spine (L1-L4), left proximal femur and total body BMD were measured by DXA at 3-month intervals. Serum 25-hydroxyvitamin D (25-OHD), serum PTH, bone markers (bone-specific ALP (BSAP) and urinary crosslinks (DYPD/creatinine)) and calcium absorption were also measured at each visit. Cholecalciferol treatment increased serum 25-OHD by 25.4 nmol/l (p < 0.001), while a reciprocal decrease in serum PTH of 6.6 ng/l (p = 0.011) was seen in subjects in the lowest quartile of baseline serum 25-OHD. The treatment had no significant effect on spine, femur or total body BMD, calcium absorption or bone markers. When Fourier analysis was used to analyze the data for seasonal effect (defined as twice the amplitude of the 1-year period variation) a highly significant effect for 25-OHD of 18 nmol/l (p < 0.001) was found. However, no effect was found for BMD, PTH, calcium absorption or bone markers. The analysis set a 95% confidence limit to the seasonal effect of less than 0.6% for spine, total hip and total body BMD. It was concluded that in the population of healthy women studied there was no evidence of seasonal variation in spine, femur or total body BMD, serum PTH, calcium absorption or bone markers. Vitamin D supplementation was found to have no effect on BMD.

Percutaneous absorption and skin irritation of JP-8 (jet fuel).

JP-8 is the major jet fuel used by US Army and Air Force. The purpose of the present study was to investigate the percutaneous absorption of JP-8 across pig ear skin and human skin in vitro and to study the effect of JP-8 exposure on the skin barrier function and irritation in Yucatan minipigs. JP-8 spiked with 5.0 microCi of radiolabeled (14C) tridecane, nonane, naphthalene or toluene (selected components of JP-8) was used for the in vitro percutaneous absorption studies with excised pig ear skin and human skin. For in vivo studies, 250 microl of JP-8 or two of its components (toluene or nonane) was placed in a Hill top chamber(R) and affixed over the marked treatment area for 24 h. Transepidermal water loss (TEWL), skin capacitance (moisture content) and skin irritation (erythema and edema) were evaluated before treatment and at 1,2 and 24 h after removal of the patches. The components of JP-8 such as tridecane, nonane, naphthalene and toluene permeated significantly through pig ear skin and human skin and the permeation rates were found to be proportional to their composition in JP-8. The steady state flux values of tridecane across pig ear skin and human skin did not differ significantly (P>0.05). Though the steady state flux values of nonane, naphthalene and toluene were statistically different between porcine and human skin (P<0.01), the values were close considering the large variations usually observed in the percutaneous absorption studies. Application of toluene, nonane or JP-8 increased the TEWL, JP-8 being the highest (3.5 times at 24 h compared to baseline level). The skin moisture content decreased after the application of JP-8, though it was not significantly different (P>0.05) from the baseline level. JP-8 caused a moderate erythema and a moderate to severe edema. Though the edema decreased after 24 h, the degree of erythema remained about the same until 24 h. The skin irritation caused by JP-8 was greater than neat toluene or nonane. The TEWL data of toluene, nonane and JP-8 correlated well with the skin irritation data (erythema and edema). Exposure of JP-8, which contains hundreds of aliphatic and aromatic hydrocarbons, caused significant changes in the barrier function of the skin as indicated by an increase in TEWL and produced a significant erythema and edema in minipigs. Furthermore, the disruption of barrier function of skin, as indicated by increased TEWL after exposure to JP-8 might result in increased permeation of its own components and/or other chemicals exposed to skin. The present study provides further evidence that pig ear skin may be used as a model for predicting the rates of permeation of chemicals through human skin.