Radioiodine Biogeochemistry and Prevalence in Groundwater.

129I is commonly either the top or among the top risk drivers, along with 99Tc, at radiological waste disposal sites and contaminated groundwater sites where nuclear material fabrication or reprocessing has occurred. The risk stems largely from 129I having a high toxicity, a high bioaccumulation factor (90% of all the body's iodine concentrates in the thyroid), a high inventory at source terms (due to its high fission yield), an extremely long half-life (16M years), and rapid mobility in the subsurface environment. Another important reason that 129I is a key risk driver is that there is uncertainty regarding its biogeochemical fate and transport in the environment. We typically can define 129I mass balance and flux at sites, but cannot predict accurately its response to changes in the environment. As a consequence of some of these characteristics, 129I has a very low drinking water standard, which is set at 1 pCi/L, the lowest of all radionuclides in the Federal Register. Recently, significant advancements have been made in detecting iodine species at ambient groundwater concentrations, defining the nature of the organic matter and iodine bond, and quantifying the role of naturally occurring sediment microbes to promote iodine oxidation and reduction. These recent studies have led to a more mechanistic understanding of radioiodine biogeochemistry. The objective of this review is to describe these advances and to provide a state of the science of radioiodine biogeochemistry relevant to its fate and transport in the terrestrial environment and provide information useful for making decisions regarding the stewardship and remediation of 129I contaminated sites. As part of this review, knowledge gaps were identified that would significantly advance the goals of basic and applied research programs for accelerating 129I environmental remediation and reducing uncertainty associated with disposal of 129I waste. Together the information gained from addressing these knowledge gaps will not alter the observation that 129I is primarily mobile, but it will likely permit demonstration that the entire 129I pool in the source term is not moving at the same rate and some may be tightly bound to the sediment, thereby smearing the modeled 129I peak and reducing maximum calculated risk.

Concentration-dependent mobility, retardation, and speciation of iodine in surface sediment from the Savannah River Site.

Iodine occurs in multiple oxidation states in aquatic systems in the form of organic and inorganic species. This feature leads to complex biogeochemical cycling of stable iodine and its long-lived isotope, (129)I. In this study, we investigated the sorption, transport, and interconversion of iodine species by comparing their mobility in groundwaters at ambient concentrations of iodine species (10(-8) to 10(-7) M) to those at artificially elevated concentrations (78.7 µM), which often are used in laboratory analyses. Results demonstrate that the mobility of iodine species greatly depends on, in addition to the type of species, the iodine concentration used, presumably limited by the number of surface organic carbon binding sites to form covalent bonds. At ambient concentrations, iodide and iodate were significantly retarded (K(d) values as high as 49 mL g(-1)), whereas at concentrations of 78.7 µM, iodide traveled along with the water without retardation. Appreciable amounts of iodide during transport were retained in soils due to iodination of organic carbon, specifically retained by aromatic carbon. At high input concentration of iodate (78.7 µM), iodate was found to be reduced to iodide and subsequently followed the transport behavior of iodide. These experiments underscore the importance of studying iodine geochemistry at ambient concentrations and demonstrate the dynamic nature of their speciation during transport conditions.

A novel approach for the simultaneous determination of iodide, iodate and organo-iodide for 127I and 129I in environmental samples using gas chromatography-mass spectrometry.

In aquatic environments, iodine mainly exists as iodide, iodate, and organic iodine. The high mobility of iodine in aquatic systems has led to (129)I contamination problems at sites where nuclear fuel has been reprocessed, such as the F-area of Savannah River Site. In order to assess the distribution of (129)I and stable (127)I in environmental systems, a sensitive and rapid method was developed which enables determination of isotopic ratios of speciated iodine. Iodide concentrations were quantified using gas chromatography-mass spectrometry (GC-MS) after derivatization to 4-iodo-N,N-dimethylaniline. Iodate concentrations were quantified by measuring the difference of iodide concentrations in the solution before and after reduction by Na(2)S(2)O(5). Total iodine, including inorganic and organic iodine, was determined after conversion to iodate by combustion at 900 °C. Organo-iodine was calculated as the difference between the total iodine and total inorganic iodine (iodide and iodate). The detection limits of iodide-127 and iodate-127 were 0.34 nM and 1.11 nM, respectively, whereas the detection limits for both iodide-129 and iodate-129 was 0.08 nM (i.e., 2pCi (129)I/L). This method was successfully applied to water samples from the contaminated Savannah River Site, South Carolina, and more pristine Galveston Bay, Texas.

Posterior lumbar apophyseal ring fractures in adolescents: a report of four cases.

Posterior lumbar apophyseal ring fractures are rare in adolescents. We report 4 such cases in Chinese adolescents. Two of the patients had a slipped capital femoral epiphysis; 3 of them were overweight/obese. All presented with low back pain and radicular pain. Apophyseal fractures of the upper lumbar spine usually involve the lower end plate, whereas those of the lumbar sacral spine usually involve the upper end plate. The radiological features and pathophysiology are discussed. Two of the patients were treated with laminotomy and diskectomy after conservative treatment failed. All patients had complete resolution of their neurological deficits at a mean follow-up of 2 years. Despite its benign nature, long-term follow-up is necessary to define the natural course and prognosis of the disease. A high index of suspicion is needed to diagnose these fractures in adolescents.

Minimally invasive repair of ruptured Achilles tendon.

OBJECTIVE: To study the clinical outcomes of minimally invasive repair of ruptured Achilles tendon. DESIGN: Retrospective study. SETTING: Orthopaedics and Traumatology Department of a public hospital in Hong Kong. PATIENTS: Fifteen consecutive patients admitted to the hospital from August 2002 to April 2005 with closed Achilles tendon rupture, had it repaired by a minimally invasive method. Parameters including patient epidemiology, nature of injuries, and isometric force measurement of ankle plantar flexion were recorded to justify the effectiveness of the Achilles tendon repair. RESULTS: Isometric peak force measurement of ankle plantar flexion 1 year after injury showed an average regain of 95% of the calf muscle strength, compared to the normal side. All wounds healed well, without major complications such as deep infection, sural nerve injury, or re-rupture of the Achilles tendon. All patients were able to resume their pre-injury activity level and previous occupation. CONCLUSION: This minimally invasive surgical technique using the Achillon suture guide produces encouraging results in the operative management of ruptured Achilles tendon.

The COMT L allele modifies the association between MAOB polymorphism and PD in Taiwanese.

OBJECTIVE: Reports suggest that catechol-O-methyltransferase (COMT(L/L)) (Val(158)/Met) and monoamine oxidase B (MAOB) intron 13 genotype polymorphism is associated with PD. To understand the ethnicity-specific effects of genetic polymorphism, we performed a case-control study of the association between PD susceptibility and polymorphism of MAOB and COMT, both separately and in combination, in Taiwanese. METHODS: Two hundred twenty-four patients with PD and 197 controls, matched for age, sex, and birthplace, were recruited. MAOB and COMT polymorphism genotyping was performed by using PCR-based restriction fragment length polymorphism (RFLP) analyses. chi(2), OR, and Fisher's exact tests were used to compare differences in allelic frequencies and genotypes. RESULTS: The MAOB G genotype (G in men and G:/G in women) was associated with a 2.07-fold increased relative risk of PD. COMT polymorphism, considered alone, showed no correlation with PD risk; however, a significant synergistic enhancement was found in PD patients harboring both the COMT(L) and MAOB G genotypes. CONCLUSIONS: These results suggest that, in Taiwanese, PD risk is associated with MAOB G intron 13 polymorphism, and this association is augmented in the presence of the COMT(L) genotype, indicating an interaction of these two dopamine-metabolizing enzymes in the pathogenesis of sporadic PD. However, the relatively low frequencies of these combined genotypes in our study necessitates confirmation with a larger sample size.

Isolation of liver nuclei that retain functional trans-membrane transport.

We have developed a method for the rapid isolation of hepatocyte nuclei, which employs gentle homogenization and centrifugation conditions, and involves minimal processing time. The purified nuclei were morphologically unaltered when observed by light and electron microscopy. No significant contamination from cytoplasm or mitochondria was detected when assessed by marker enzymes. Membrane transport function, measured as ATP-dependent calcium uptake, was intact. This isolation method was devised to be applicable to studies that involve measurement of uptake and active transport of a variety of substances by the cell nucleus.

Determination and pharmacokinetic profile of omeprazole in rat blood, brain and bile by microdialysis and high-performance liquid chromatography.

The disposition and biliary excretion of omeprazole was investigated following i.v. administration to rats at 10 mg/kg. We used a microdialysis technique coupled to a validated microbore HPLC system to monitor the levels of protein-unbound omeprazole in rat blood, brain and bile, constructing the relationship of the time course of the presence of omeprazole. Microdialysis probes were simultaneously inserted into the jugular vein toward right atrium, the brain striatum and the bile duct of the male Sprague-Dawley rats for biological fluid sampling after the administration of omeprazole (10 mg/kg) through the femoral vein. The concentration-response relationship from the present method indicated linearity (r2>0.995) over a concentration range of 0.01-50 microg/ml for omeprazole. Intra-assay and inter-assay precision and accuracy of omeprazole fell well within the predefined limits of acceptability. Following omeprazole administration, the blood-to-brain coefficient of distribution was 0.15, which was calculated as the area under the concentration versus time curve (AUC) in the brain divided by the AUC in blood (k=AUCbrain/AUCblood). The blood-to-bile coefficient of distribution (k=AUCbile/AUCblood) was 0.58. The decline of unbound omeprazole in the brain striatum, blood and bile fluid suggests that there was rapid exchange and equilibration between the compartments of the peripheral and central nervous systems. In addition, the results indicated that omeprazole was able to penetrate the blood-brain barrier and undergo hepatobiliary excretion.

Phase I clinical trial of curcumin, a chemopreventive agent, in patients with high-risk or pre-malignant lesions.

Curcumin (diferuloylmethane), a yellow substance from the root of the plant Curcuma longa Linn., has been demonstrated to inhibit carcinogenesis of murine skin, stomach, intestine and liver. However, the toxicology, pharmacokinetics and biologically effective dose of curcumin in humans have not been reported. This prospective phase-I study evaluated these issues of curcumin in patients with one of the following five high-risk conditions: 1) recently resected urinary bladder cancer; 2) arsenic Bowen's disease of the skin; 3) uterine cervical intraepithelial neoplasm (CIN); 4) oral leucoplakia; and 5) intestinal metaplasia of the stomach. Curcumin was taken orally for 3 months. Biopsy of the lesion sites was done immediately before and 3 months after starting curcumin treament. The starting dose was 500 mg/day. If no toxicity > or = grade II was noted in at least 3 successive patients, the dose was then escalated to another level in the order of 1,000, 2,000, 4,000, 8,000, and 12,000 mg/day. The concentration of curcumin in serum and urine was determined by high pressure liquid chromatography (HPLC). A total of 25 patients were enrolled in this study. There was no treatment-related toxicity up to 8,000 mg/day. Beyond 8,000 mg/day, the bulky volume of the drug was unacceptable to the patients. The serum concentration of curcumin usually peaked at 1 to 2 hours after oral intake of crucumin and gradually declined within 12 hours. The average peak serum concentrations after taking 4,000 mg, 6,000 mg and 8,000 mg of curcumin were 0.51 +/- 0.11 microM, 0.63 +/- 0.06 microM and 1.77 +/- 1.87 microM, respectively. Urinary excretion of curcumin was undetectable. One of 4 patients with CIN and 1 of 7 patients with oral leucoplakia proceeded to develop frank malignancies in spite of curcumin treatment. In contrast, histologic improvement of precancerous lesions was seen in 1 out of 2 patients with recently resected bladder cancer, 2 out of 7 patients of oral leucoplakia, 1 out of 6 patients of intestinal metaplasia of the stomach, I out of 4 patients with CIN and 2 out of 6 patients with Bowen's disease. In conclusion, this study demonstrated that curcumin is not toxic to humans up to 8,000 mg/day when taken by mouth for 3 months. Our results also suggest a biologic effect of curcumin in the chemoprevention of cancer.

Effects of Hemerocallis flava on motor activity and the concentration of central monoamines and its metabolites in rats.

In this study, we used behavioral and biochemical methods to investigate the effects of Hemerocallis flava (Liliaceae) (abbreviated as HF) on motor activity and the concentration of monoamines in rats. The water fraction of the resuspended HF extract was most active in reducing the motility in rats. The water fraction of the HF extract enhanced the reduction of locomotor activity produced by alpha-methyl-p-tyrosine and 5-hydroxytryptophan, but it reduced the increase of locomotor activity produced by L-dopa plus benserazide and p-chlorophenylalanine. Furthermore, the water fraction of the HF extract significantly decreased the concentration of norepinepherine in the cortex and the concentration of dopamine and serotonin in the brain stem. It also increased the concentration of vanilylmandelic acid in the cortex, homovanillic acid and 5-hydroxyindole-acetic acid in the brain stem. These results suggest that the reduction of locomotor activity produced by the water fraction of HF extract may be related to the decrease in the concentration of norepinepherine in the cortex and the concentration of dopamine and serotonin in brain stem.

Comparative study of artery cuff and fat wrap in microvascular anastomosis in the rat.

An artery cuff and a fat wrap placed around an anastomosis with only 4 stitches were compared to the conventional 8-10 stitches suturing technique in microvascular anastomosis: 120 vessels in 40 immature male S-D rats were used. Observations were made 1 hour, and 1, 2, 3 and 8 weeks after the repair. The newer techniques were performed faster, had shorter bleeding time and showed equivalent patency rates to the conventional technique. The artery cuff was slightly superior to the fat wrap, particularly in having fewer adhesions and a better histological picture. Clinical applications are discussed.

Survey of foot deformities among 166 geriatric inpatients.

A clinical survey on foot deformities among 166 geriatric inpatients was carried out. Direct measurements on hallux valgus, great toe movements, great toe deformities, lesser toe deformities, arch of the foot, callosities, ankle movements, inversion, and eversion were done by using the goniometer. A specially designed goniometer was created to measure inversion and eversion. The Harris Mat was used to study foot prints in correlation with the various deformities. About 50% of geriatric patients were found to have foot deformities of various types. This compared well with available data in literature. The target population was also checked for their symptomatology which, amazingly, was found to be really insignificant compared with the deformities present. This finding was found to be very much unlike data for Caucasian individuals with foot deformities, 50% of whom had symptoms related to pain and footwear. This major difference in the clinical presentation encourages the authors to carry on their study and, perhaps, direct cross-cultural studies in the future.

Pyogenic osteomyelitis of the spine--a review of 16 consecutive cases.

Pyogenic osteomyelitis of the spine is an uncommon disease. A series of 16 cases is reported. The site of involvement includes the lumbar, cervical, and thoracic segments, in that order of frequency of occurrence. Drug addiction and diabetes mellitus are important predisposing factors. The spectrum of clinical presentation is described. Late presentation is usually masked by old age, debilitation, and previous antibiotic treatment. Rapid progression with septicemia is also encountered. The importance of differentiating this condition from tuberculosis spondylitis is emphasized. Definitive diagnosis should depend on bacteriological, histological, and, with the recent introduction of antituberculosis antibody test, serological studies. Timely surgical intervention is indicated in complicated cases. Radical excision and anterior spinal fusion yields early and complete eradication of the infected material plus arthrodesis, which prevents late collapse of the spine.

Fractured proximal end of the femur in the elderly--a medico-social study.

278 geriatric patients with fractured proximal end of the femur were studied retrospectively 1.5-5 years (average 3.5 years) after they received treatment in two hospitals. Of the survivors 63%, 56% were totally pain-free while 15% had varying degrees of hip pain. Only 26.5% could squat fully. The physical activity was inversely proportional to the age. The widowed were doing better than the married with living husbands. Of the three methods of treatment (Austin-Moore hemiarthroplasty, plating and Ender's nailing), the hemiarthroplasty group of patients was doing the best physically. In spite of some positive X-ray findings among the different groups, corresponding clinical manifestations were not encountered.

Heterotrimeric G-protein and signal transduction in the nematode-trapping fungus Arthrobotrys dactyloides.

The fungus Arthrobotrys dactyloides produces specialized constricting rings to trap and then consume nematodes. The signal transduction pathway involved in the nematode-trapping process was examined. Mastoparan, an activator of G-protein, had a stimulatory effect on the inflation of ring cells, whereas a G-protein inhibitor, pertussis toxin, prevented ring-cell expansion. The 40-kDa G alpha of heterotrimeric G-proteins was specifically ADP-ribosylated by pertussis toxin. Using an antibody specific to the 35-kDa subunit G beta, we showed that immunogold-labeled G beta was more concentrated in ring cells than in the hyphae. In the absence of nematodes, the rings could be inflated by either pressurizing the culture in a syringe, raising intracellular Ca2+ concentrations, or adding warm water. We used these methods to reveal differences in responses to antagonists. The results support a model in which the pressure exerted by a nematode on the ring activates G-proteins in the ring cells. The activation leads to an increase in cytoplasmic Ca2+, activation of calmodulin, and finally the opening of water channels. The ring cells expand to constrict the ring and thus immobilize the nematode.

Genetic polymorphism of the CYP2E1 gene and susceptibility to Parkinson's disease in Taiwanese.

Cytochrome p450IIE1 (CYP2E1), an ethanol-inducible cytochrome p450 enzyme, is expressed in the basal ganglia and is probably involved in the activation of neurotoxicants, producing free radical metabolites and resulting in oxidative stress. To examine the association between CYP2E1 polymorphism and the risk of Parkinson's disease (PD), we performed a case-control study on a large population of Taiwanese PD patients, focusing especially on early-onset PD patients (onset at, or before, the age of 50). Two hundred and thirty-four PD patients and 251 age- and sex-matched controls were recruited. A much higher frequency of the uncommon c2 allele was seen in our control subjects than in Caucasians (0.23 vs. 0.02). There were no significant differences between PD patients and controls in the distribution of either allelic or genotype frequencies. Our results suggest that CYP2E1 is not a major or independent determinant in the occurrence of PD in Taiwanese.