Phylogenetic Analysis of Mycobacterium tuberculosis Strains in Wales by Use of Core Genome Multilocus Sequence Typing To Analyze Whole-Genome Sequencing Data.

An inability to standardize the bioinformatic data produced by whole-genome sequencing (WGS) has been a barrier to its widespread use in tuberculosis phylogenetics. The aim of this study was to carry out a phylogenetic analysis of tuberculosis in Wales, United Kingdom, using Ridom SeqSphere software for core genome multilocus sequence typing (cgMLST) analysis of whole-genome sequencing data. The phylogenetics of tuberculosis in Wales have not previously been studied. Sixty-six Mycobacterium tuberculosis isolates (including 42 outbreak-associated isolates) from south Wales were sequenced using an Illumina platform. Isolates were assigned to principal genetic groups, single nucleotide polymorphism (SNP) cluster groups, lineages, and sublineages using SNP-calling protocols. WGS data were submitted to the Ridom SeqSphere software for cgMLST analysis and analyzed alongside 179 previously lineage-defined isolates. The data set was dominated by the Euro-American lineage, with the sublineage composition being dominated by T, X, and Haarlem family strains. The cgMLST analysis successfully assigned 58 isolates to major lineages, and the results were consistent with those obtained by traditional SNP mapping methods. In addition, the cgMLST scheme was used to resolve an outbreak of tuberculosis occurring in the region. This study supports the use of a cgMLST method for standardized phylogenetic assignment of tuberculosis isolates and for outbreak resolution and provides the first insight into Welsh tuberculosis phylogenetics, identifying the presence of the Haarlem sublineage commonly associated with virulent traits.

Audit of a network of sexually transmitted infections centred in South Wales.

The aim of this article is to audit the distribution and frequency of sexually transmitted infections (STIs) within a sexual network centred in South Wales. After diagnosis of a new case of HIV in February 2007, partner notification, HIV and STI testing were undertaken. Those traced were given information regarding safe sex practices and informed they had been in contact with HIV. Genitourinary (GU) medicine case-notes of contacts identified in the network were reviewed from February 2007 to 1 July 2008. Frequency and distribution of new diagnoses of STIs made on original identification in the network in 2007 were compared with subsequent new diagnoses within the network. One hundred and eighteen men who have sex with men (MSMs) and five women were identified in the original network in 2007. By 1 July 2008, 65 new sexual contacts (all MSMs) were added to the network and there were 25 new STI diagnoses in 13 contacts. Seven contacts originally identified in the cluster in 2007 were diagnosed with 16 of the new STIs. In conclusion, the sexual network has evolved by increasing in size with multiple new STIs diagnosed. The highest risk of STIs occurred in relatively few individuals. Standard interventions in health promotion in the GU medicine setting were not universally successful in preventing high-risk behaviour.

Sepsis programme successes are responsible for the increased detection of bacteraemia.

BACKGROUND: Escherichia coli bacteraemia reduction targets are challenging but, in West Wales, this was the key infection surrogate measure set by the local health board in 2013, prior to the introduction of a Welsh Government target. The initial plateau of cases was not maintained and prompted this review. AIM: To review all blood cultures submitted between 2002 and 2016, both positive and negative. METHODS: With access to a microbiology data warehouse in Wales, all blood culture results were collected, extracted to Excel tables and analysed using change point analysis. FINDINGS: Just under 200,000 blood culture results were examined. This study found an increase in blood culture submissions, but the positivity rate remained constant throughout the period and the increased number of E. coli reflected the increased number of blood cultures taken. This demonstrated the success of sepsis awareness and the use of sepsis bundles for rapid diagnosis and management. CONCLUSION: Success in one area (sepsis management) conflicts with 'failure' in reducing E. coli bacteraemia. It is argued that targets need to be considered carefully in the light of all available information, which have currently set the National Health Service up to fail.

Investigation of an HIV transmission cluster centred in South Wales.

OBJECTIVE: To describe an HIV transmission cluster centred in South Wales by the analysis of partner notification outcomes and demographic characteristics of individuals identified in the sexual network. METHODS: After diagnosis of the index case, HIV testing and partner notification were undertaken by Cardiff Genitourinary Medicine Clinic in collaboration with the local Health Protection Team, National Public Health Service for Wales and Terrence Higgins Trust Cymru. Rapid test and standard venepuncture methods were used for HIV screening and the resulting clinical and behavioural data were analysed. RESULTS: Of the 123 individuals identified in the sexual network, all were men who had sex with men (MSM) except for seven men who self-identified as bisexual and five heterosexual women. Fifteen new cases of HIV were diagnosed; all were men. Partner notification outcomes are as follows: 104 provider referrals were made, 57 were successfully contacted with known outcomes, 14 were successfully contacted but with unknown outcomes and 33 were uncontactable. Fifteen patient referrals were made, 11 had known outcomes but four had unknown outcomes. Four patients self-referred. Eleven reported previous HIV diagnosis. The sexual network was distributed over South and West Wales extending into England, with high reported rates of unprotected anal intercourse, previous HIV tests and concurrent sexually transmitted infections. A one in four positive rate for those with a known HIV status outcome and a 68% provider referral success rate compares favourably with other studies. CONCLUSIONS: Partner notification revealed a relatively young, well-educated HIV network with high-risk behaviour and ongoing transmission despite previous knowledge and awareness of HIV. This analysis adds to the evidence supporting HIV partner notification in MSM.

Use of epidural clonidine for the management of analgesia in the opioid addicted parturient on buprenorphine maintenance therapy: an observational study.

OBJECTIVES: Management of labor analgesia and post-cesarean delivery pain is challenging in the patient taking buprenorphine as opioid addiction maintenance therapy. We observed whether substituting clonidine for fentanyl in an epidural solution would provide adequate analgesia for labor and after cesarean delivery. METHODS: We substituted our standard 2 µg/mL fentanyl in 0.0625% bupivacaine epidural solution with 2 µg/mL clonidine in 0.0625% bupivacaine, or 1.2 µg/mL clonidine in 0.1% bupivacaine, for labor and post-cesarean analgesia in parturients on buprenorphine therapy. All cesarean deliveries were performed with a combined spinal-epidural technique and the catheters maintained for immediate postoperative analgesia using an epidural infusion. Catheters were discontinued the next day and patients were then managed with other analgesics based on obstetric preference. We recorded pain scores during labor and in the immediate post-surgical period; and supplemental medications given after epidural catheter removal. RESULTS: Fourteen patients were included in the study, of whom seven presented in spontaneous labor and seven had elective cesarean delivery. All laboring patients achieved good analgesia, and five of seven avoided supplemental opioid use in the postpartum phase. Of the postsurgical patients, six of seven had pain scores less than 5/10 at epidural catheter removal and three of seven avoided supplemental opioids postoperatively. CONCLUSIONS: The combination of clonidine and bupivacaine appears effective in parturients on buprenorphine therapy for opioid addiction maintenance. As study numbers were small and several factors were not examined, further confirmatory research is needed, including to determine the ideal dose of epidural clonidine in this setting.

Effects of dose and duration of continuous GnRH-agonist treatment on induction of estrus in beagle dogs: competing and concurrent up-regulation and down-regulation of LH release.

Dose-response estrus-induction trials were conducted during anestrus in 93 treated and 6 control bitches, a continuous administration of the GnRH-agonist lutrelin with a potency 150 x GnRH, and at six different doses from 0.2 to 4.8 microg/kg/d for 7-14 days in 15 groups of six to eight dogs each in defined stages of natural or pharmacologically determined anestrus. Agonist treatment induced clinically and cytologically normal proestrus (in 89% of cases) within 4.8 +/- 0.2 x days, and resulted in behavioral estrus (71%), spontaneous late-proestrus LH (and FSH) surges, ovulation (59%) and pregnancy (44%) in a dose dependent manner. Outcomes of ovulation and pregnancy in most cases required that the dose be sufficiently large enough to routinely stimulate a large initial increase in LH and FSH (i.e., > or = 0.6 microg/kg/d), and of sufficient duration (i.e., > 7 days) to ensure that supra-basal gonadotropin levels persistedntil no longer needed for spontaneous continuation of an induced proestrus. Success additionally required that the GnRH dose be modest enough (i.e., < 1.8 microg/kg/d) to not excessively down-regulate spontaneous pre-ovulatory surge release of gonadotropin or be removed shortly before or at the time when the LH surges typically occurred (10-13 days after initiation of treatment). The 1.8 microg dose was compared to saline to assess the time course of its down-regulation action on serum LH in six ovariohysterectomized bitches compared to four saline-related controls. Results in intact bitches receiving the 1.8-microg doses demonstrated an LH-releasing effect for 10-11 days that overlapped a period of obvious down-regulation seen with the same dose after 3 days in the ovariohysterectomized bitches. In the latter, however, complete down-regulation to anestrus-like values did not occur until after 18-21 days of treatment. A dose of 0.6 microg/kg/d for 12 days yielded the best estrus-induction results, including pregnancy rates of 100% in six bitches treated in natural-anestrus bitches, six bitches in which anestrus had been advanced by a luteolytic prostaglandin treatment and in six bitches in which anestrus had been extended by progesterone implants administered for 3 months. Although lutrelin is not commercially available, these results provide guidelines for the development of estrus-inducing protocols with other GnRH-agonists of known biopotencies.

Biological characterization of an Epstein-Barr nuclear antigen-positive American Burkitt's tumor-derived cell line.

Two distinct cultures derived from a lymphoid cell line designated NAB were characterized immunologically, morphologically, and cytogenetically. Both cultures were positive for Epstein-Barr nuclear antigen. NAB I cultures were negative for virus capsid antigen and early antigen and were not affected by treatment with 5-iododeoxyurdine. NAB II cultures were positive for virus capsid antigen and early antigen, which increased with 5-iododeoxyuridine treatment. Both cultures were superinfected with virus prepared from P3HR-1 cells. Cell-free virus concentrates prepared from both cultures were inactive for transformation and infectivity. NAB I and NAB II cells were lymphoid as determined by light and electron microscopy. NAB II cells showed morphological alterations characteristic of herpes infection. 5-iododeoxyuridine-treated cells from both cultures revealed ultrastructural characteristics of cells infected with herpes-viruses but without particles. In addition, the induction of tubuloreticular structures within the endoplasmic reticulum was observed. Cytogenetic analysis of both cultures revealed a rearranged chromosome 14 and several other chromosome aberrations, three of which may be used as a reliable means of identifying NAB cultures.

Gonadal function is associated with cardiometabolic health in pre-pubertal boys with Klinefelter syndrome.

The most common sex chromosome aneuploidy, Klinefelter syndrome (KS), is associated with primary gonadal failure and increased morbidity and mortality from cardiometabolic disorders in adulthood. Children with KS also have a high prevalence of metabolic syndrome (MetS) features. To assess the relationship of gonadal and cardiometabolic function in children with KS, we evaluated serum hormones [gonadotropins, inhibin B (INHB), anti-mullerian hormone (AMH), total testosterone (TT)], and features of MetS (waist circumference, fasting lipid panel, fasting blood glucose (FBG), and blood pressure) in 93 pre-pubertal boys with KS age 4-12 years (mean 7.7 ± 2.5 years). The cohort was grouped by age and tanner stage, and biomarkers were compared to normal ranges. A total of 80% of this pre-pubertal cohort had ≥1 feature of metabolic syndrome (MetS) and 11% had ≥3 features of MetS. Risk of MetS was independent of age and body mass index. Sertoli cell dysfunction was common with 18% having an INHB below the normal range. A low INHB was associated with higher FBG, triglycerides, LDL, and lower HDL (p < 0.05). An INHB <50 ng/dL yielded a sensitivity of 83% and a specificity of 79% for having ≥3 features of MetS. INHB and AMH positively correlated with each other (p < 0.001), and high AMH was protective of MetS. TT was below the lower limit of normal in 49% of subjects, with mean values significantly lower than expected (3.3 ng/dL vs. 4.9 ng/dL, p < 0.0001), however, no convincing relationship between TT and MetS was seen. In conclusion, gonadal and cardiometabolic dysfunction are prevalent in pre-pubertal boys with KS. Although the relationship of testosterone deficiency and MetS is well-known, this study is the first to report an association between impaired Sertoli cell function and cardiometabolic risk.

Interaction of 11 cisplatin analogues with DNA: characteristic pattern of damage with monofunctional analogues.

In this paper the sequence specificity of DNA damage has been determined for 11 cisplatin analogues. A number of the analogues used in this study have been included in clinical trials. A Taq DNA polymerase linear amplification technique was utilised to ascertain the sequence selectivity of cisplatin analogues damage to DNA. The analogues differed in their ability to damage DNA with cisplatin being the most effective DNA damaging agent followed by (in decreasing order): tetraplatin (tetrachloro(1,2-diaminocyclohexane)platinum(IV) (RR isomer)), cis-dichlorobis(isopropylamine)platinum(II), dichloro(1,2-diaminocyclohexane)platinum(II) (SS isomer), dichloro(1,2-diaminocyclohexane)platinum(II) (RR isomer), cis-bis(cyclohexylamine)dichloroplatinum(II), carboplatin, cis-dichlorobis(isopentylamine)platinum(II), and CHIP (cis-dichloro-trans-dihydroxybis(isopropylamine)platinum(IV)). However, the sequence specificity of these analogues was similar in position and relative intensity of damage. We also provide evidence that platinum(IV) complexes can damage DNA without being reduced to platinum(II). It was found that a 10-fold higher concentration of cisplatin was required to damage DNA in Tris-HCl compared to Hepes buffers. In this paper we have detected a characteristic pattern of damage with monofunctional analogues that could be used to determine the mode of binding of a cisplatin analogue with DNA. The monofunctional analogues tested were chloro(diethylenetriamine)platinum(II) and cis-diamminechloro(1-octylamine)platinum(II) as well as transplatin.

Protein-DNA footprinting of the human epsilon-globin promoter in human intact cells using nitrogen mustard analogues and other DNA-damaging agents.

Nitrogen mustard analogues, bleomycin and dimethyl sulphate (DMS) have been used as probes of protein-DNA interactions in intact human cells. The sites of damage have been determined at base pair resolution in the single copy epsilon-globin gene promoter in erythroid K562 cells, non-erythroid HeLa cells and purified DNA. Exponential amplification of gene-specific damage fragments was achieved using the ligation-mediated polymerase chain reaction (LMPCR) technique and analysed on DNA sequencing gels. A comparison of the relative damage band intensities between purified DNA and intact cells revealed several significant differences - both protection (footprint) and enhancement. These differences occurred at putative transcription factor binding sites and hence are thought to be due to protein-DNA interactions. A major feature of the band intensity ratio plots was the footprint observed at the CCAAT box binding motif as revealed by nitrogen mustard analogues. Enhanced band intensity (hypersensitivity) was displayed at the 5'- and 3'-ends of the CCAAT box in K562 cells - this feature was absent in HeLa cells and in vitro reconstitutions. A footprint was found at the GATA-1 motif in K562 cells that was also absent in non-expressing HeLa cells. Footprints were also evident at the TATA box, CACC box and the epsilonF1 DNA binding motif in K562 cells.

The reliability and repeatability of the blood glucose response to prolonged exercise in adolescent boys with IDDM.

OBJECTIVE: To determine the intrasubject reliability and repeatability of the blood glucose response to prolonged exercise in adolescents with insulin-dependent diabetes mellitus (IDDM) when pre-exercise meal, exercise, and insulin regimens are kept constant. RESEARCH DESIGN AND METHODS: Nine IDDM adolescent boys with diabetes duration of 9.7 +/- 4.8 years participated in two testing sessions 5-17 days apart. Carbohydrate intake, subcutaneous insulin injections, exercise bouts, and their timing were identical in both sessions. Exercise started 1 h after breakfast and consisted of six 10-min cycling bouts at moderate intensity (heart rate 145-150 beats/min), separated by 5-min rest periods. During rest periods, blood samples for glucose were taken and a supplemental carbohydrate beverage was consumed. Subjects were asked periodically to guess their own blood glucose levels. RESULTS: Intersession plasma glucose levels for each time period from the start of exercise to the end of the final recovery period were unchanged between sessions (P > 0.05) and highly correlated (r = 0.88 to r = 0.96, P < 0.01). The intraclass correlation for plasma glucose was 0.95. Decreases in plasma glucose from the start of exercise to the end of exercise were, at most 5 mmol/l, and intersession decreases did not differ significantly (P > 0.05). One subject experienced hypoglycemia. The decrease in plasma glucose did not differ significantly between fair and poor glycemic control (glycosylated hemoglobin < or = 10% and > 10%, respectively). Subjects markedly underestimated their blood glucose levels when they were high, but their guesses were closer to the measured values at lower levels. CONCLUSIONS: --Intersession observations demonstrated that the intrasubject blood glucose responses to prolonged moderate-intensity exercise were reliable and repeatable when pre-exercise meal, exercise, and insulin, regimens were kept constant. This is an important finding for implementing and evaluating educational strategies for improving the metabolic control associated with prolonged exercise, as well as for future research on means for preventing exercise-induced hypoglycemia.

Unsafe sexual behavior and alcohol use at the event level: results of a national survey.

In recent years, several researchers have suggested that the use of alcohol in conjunction with sexual activity significantly increases the probability that unsafe or risky sexual behavior will occur. However, the majority of studies examining this relationship have utilized general measures of drinking frequency and sexual behavior, and are therefore unable to establish whether the drinking and risky sex occur on the same occasion. In this study, adult respondents in a national survey were asked about the circumstances of two sexual encounters: their most recent sexual experience and their most recent encounter involving a new sexual partner. The characteristics of encounters that involved and did not involve drinking are described. The results showed that although encounters with new partners were more likely to involve alcohol, the presence of alcohol in the event was not significantly associated with risky sexual activity. The occurrence of risky sexual behavior was predicted by a number of individual and situational variables, including sexual attitudes, drinking habits, and personality characteristics. These findings suggest that the relationship between drinking and risky sex is the result of a complex interaction among personality, situational, and behavioral factors.

A prospective, longitudinal study of central venous catheter-related deep venous thrombosis in boys with hemophilia.

BACKGROUND: Central venous catheters (CVCs) are often inserted into boys with hemophilia to secure venous access for factor prophylaxis and immune tolerance induction therapy. Complications associated with CVCs include catheter-related infections, local hemorrhage, and mechanical failure. Less frequently reported is CVC-related deep venous thrombosis (DVT). We conducted a prospective study to determine the frequency and outcome of this complication. METHODS: All boys (n = 16) with congenital hemophilia A or B with a CVC in place who were registered in the pediatric comprehensive care program at the Hospital for Sick Children, Toronto, were included in the study. They were prospectively assessed by imaging studies and clinical examinations for CVC-related DVT at two time-points, 2 years apart. Each boy was evaluated for inherited hypercoagulability. RESULTS: Eleven (69%) of the 16 boys had radiological evidence of DVT at the first evaluation and 13/16 (81%) at the second evaluation. In two boys there was improvement in the venogram findings at the second evaluation. None of the CVC-related DVTs completely resolved. Median age at the time of initial insertion of a CVC was 1.0 years (range 0.02-6.7 years). Median duration of CVC placement was 6.4 years (range 3.3-15.5 years). Only 4/13 boys with DVTs had clinical evidence of upper venous system obstruction. Only one boy, who did not develop a DVT, had a low protein C level. CONCLUSIONS: CVC-related DVTs occur in the majority of boys with hemophilia who have CVCs inserted for a prolonged period of time. Annual screening with imaging is recommended for boys with CVCs in place for >/= 3 years. Consideration should be given to removing CVCs as soon as peripheral venous access is feasible.

Sporozoites of Toxoplasma gondii lack dense-granule protein GRA3 and form a unique parasitophorous vacuole.

The invasion of host cells by sporozoites of Toxoplasma gondii leads to the formation of parasitophorous vacuoles that are distinctly different from those surrounding tachyzoites. In sporozoite-infected cells, the fluid-filled space surrounding the sporozoite is many times larger in volume than the sporozoite, essentially lacks granular or tubular structures, and has no detectable continuous parasitophorous vacuolar membrane when prepared by conventional electron microscopic methods. Consistent with the ultrastructural differences, dense-granule protein GRA3, which associates with the parasitophorous vacuolar membrane of tachyzoites, was not detected by indirect immunofluorescence in sporozoite-infected cells 2-12 h post-inoculation or by Western blot analysis of sporozoite extracts. Western blots incubated with the alpha ROP/DG antiserum, which recognizes tachyzoite rhoptry and dense-granule proteins, revealed numerous other antigenic differences between sporozoites and tachyzoites. Cell cultures inoculated with sporozoites were monitored at various intervals for the expression of GRA3 and the developmentally-regulated tachyzoite surface protein SAG1. Expression of SAG1 and GRA3 was first observed in 30% of the sporozoite-infected cells at 12 and 15 h post-inoculation, respectively, and in all intracellular parasites at 24 h. Parasite replication was only observed in sporozoite-infected cells that were positive for GRA3 and SAG1. Thus, these data indicate that sporozoites and their interaction with host cells differ substantially from tachyzoites and the expression of tachyzoite-specific proteins is likely required for parasite replication.

Comparative palatability of 22 liquid antacids.

OBJECTIVE: To compare the palatability, acid neutralizing capability, and costs of different antacids. METHODS: Volunteers between the ages of 18 and 60 years were given 22 antacids. All antacids were given during a 4-h period in two groups of 11 antacids each. Subjects sampled each antacid in a manner similar to wine tasting and rated each antacid on its smell, taste, texture and aftertaste using a scale of 1-9; 1 being the worst and 9 the best. RESULTS: A total of 73 adults completed the study. Mylanta Lemon Twist and Mylanta Cherry Crème were the most palatable antacids; however, overall the palatability of all the antacids was poor. Maalox MS Cool Mint and ES Gaviscon were the least palatable. The extra strength antacids had the most acid neutralizing capability, and thus would require smaller doses. Amphogel was the most costly antacid per mEq of acid neutralized. Age and gender did not affect the palatability scores. CONCLUSION: Although the regular strengths of Mylanta Lemon Twist and Mylanta Cherry Crème were the most palatable, the extra strength versions of these products have twice the acid neutralizing capability and thus, half the volume is required for each dose. Therefore, these agents may be the antacids of choice.

Effect of tetrahydroaminoacridine, a cholinesterase inhibitor, on cognitive performance following experimental brain injury.

An emerging literature exists in support of deficits in cholinergic neurotransmission days to weeks following experimental traumatic brain injury (TBI). In addition, novel cholinomimetic therapeutics have been demonstrated to improve cognitive outcome following TBI in rats. We examined the effects of repeated postinjury administration of a cholinesterase inhibitor, tetrahydroaminoacridine (THA), on cognitive performance following experimental TBI. Rats were either injured at a moderate level of central fluid percussion TBI (2.1+/-0.1 atm) or were surgically prepared but not delivered a fluid pulse (sham injury). Beginning 24 h after TBI or sham injury, rats were injected (IP) daily for 15 days with an equal volume (1.0 ml/kg) of either 0.0, 1.0, 3.0, or 9.0 mg/kg THA (TBI: n = 8, 8, 10, and 7, respectively, and Sham: n = 5, 7, 8, 7, respectively). Cognitive performance was assessed on Days 11-15 after injury in a Morris water maze (MWM). Analysis of maze latencies over days indicated that chronic administration of THA produced a dose-related impairment in MWM performance in both the injured and sham groups, with the 9.0 mg/kg dose producing the largest deficit. The 1.0 and 3.0 mg/kg doses of THA impaired MWM performance without affecting swimming speeds. Thus, the results of this investigation do not support the use of THA as a cholinomimetic therapeutic for the treatment of cognitive deficits following TBI.

Exposure to environmental complexity promotes recovery of cognitive function after traumatic brain injury.

This study was designed to determine whether exposure to a complex environment after traumatic brain injury (TBI) would promote the recovery of cognitive function. Rats were injured at a moderate level of fluid percussion injury (2.1 atm) or were prepared for injury but were not injured (sham injury). Immediately after the injury or sham injury, the injured/complex (n = 8) and the sham/complex (n = 7) groups were placed into a complex environment. The complex environment was a 89 x 89-cm enclosure with different types of bedding and objects that provided motor, olfactory, tactile, and visual stimulation. The injured/standard (n = 8) and the sham/standard (n = 8) groups were returned to the animal vivarium where they were housed individually in standard wire mesh cages (24 x 20 x 18 cm). On days 11-15 (postinjury), performance in the Morris water maze was assessed. Analysis of the latency to reach the goal platform indicated that injured animals recuperating in the complex environment performed significantly better than injured animals recovering in the standard environment (p < 0.01). In fact, injured animals in the complex environment performed as well as both sham-injured groups. The improved performance of injured rats recovering in the enriched environment occurred in the absence of environmentally induced alterations in brain weight. These results indicate that exposure to environmental complexity enhances recovery of cognitive function after TBI.

The effect of postinjury administration of polyethylene glycol-conjugated superoxide dismutase (pegorgotein, Dismutec) or lidocaine on behavioral function following fluid-percussion brain injury in rats.

Previous studies in our laboratory have shown that polyethylene glycol-conjugated superoxide dismutase (PEG-SOD) or lidocaine treatment before experimental fluid-percussion brain injury in rats reduces the cortical hypoperfusion normally found in the early posttraumatic period. The purpose of the current study was to determine if posttreatment with PEG-SOD or lidocaine is also associated with changes in the trauma-induced suppression of motor and cognitive function that occurs following traumatic brain injury (TBI). Twenty-four hours after surgical preparation, rats were randomly assigned to a saline or drug posttreatment group, PEG-SOD (pegorgotein, Dismutec 10,000 IU/kg) or lidocaine (2 mg/kg), which was injected iv 30 min after moderate injury. PEG-SOD completely prevented beam walk deficits on days 1-5 postinjury while lidocaine similarly prevented beam walk deficits on days 2 through 5 postinjury. Both drugs produced a statistically insignificant trend for a decrease in beam balance duration deficits on days 1-5 postinjury and had no effect on cognitive function, as assessed by the Morris water maze, on days 11 through 15 postinjury. The mechanism by which PEG-SOD and lidocaine reduce posttraumatic motor deficits may be related to their free radical scavenging effect or previously reported effects on posttraumatic cerebral blood flow. To our knowledge, this is the first report of the effectiveness of these two agents in laboratory animals when administered after traumatic injury.

Small shifts in craniotomy position in the lateral fluid percussion injury model are associated with differential lesion development.

Previous studies have shown that location and direction of injury may affect outcome in experimental models of traumatic brain injury. Significant variability in outcome data has also been noted in studies using the lateral fluid percussion brain injury model (FPI) in rats. In recent studies from our laboratory, we observed considerable variability in localization and severity of tissue damage as a function of small changes in craniotomy position. To further address this issue, we examined the relationship between craniotomy position and brain lesion size/location in rats subjected to moderate FPI (2.28 +/- 0.18 atmospheres). With placement of a 5-mm craniotomy adjacent to the sagittal suture, there was both ipsilateral and contralateral damage as detected at 3 weeks posttrauma using T2-weighted magnetic resonance imaging (MRI). The MRI lesions were generally restricted to the hippocampus and subcortical layers. Shifting of the craniotomy site laterally was associated with increased ipsilateral tissue damage and a greater cortical component that correlated with distance from the sagittal suture. In contrast, the contralateral MRI lesion did not change significantly in size or location unless the center of the craniotomy was placed more than 3.5 mm from the sagittal suture, under which condition contralateral damage could no longer be detected. Ipsilateral tissue damage as determined from the MRI scans was linearly correlated to motor outcome but not with cognitive outcome as assessed by the Morris Water Maze. We conclude that craniotomy position is critical in determining extent and location of tissue injury produced during the lateral FPI model in rats. Addressing such potential variability is essential for studies that address either injury mechanisms or therapeutic treatments.