Screening for complement deficiency in bacterial meningitis

Seventy-seven children with bacterial meningitis were screened for complement deficiency. Both the classical and the alternate pathways were normal in 75 patients. Transiently reduced total haemolytic activity of the classical pathway was documented in a boy with meningococcal meningitis. Total haemolytic activity of both the classical and the alternate pathways were reduced in another patient with pneumococcal meningitis: individual complement components determination indicated predominant activation of the alternate pathway.     

Inositol 1,4,5-trisphosphate turnover enzymes--activities and subcellular distribution in hepatocarcinogenesis

The metabolism of inositol 1,4,5-trisphosphate and inositol 1,3,4,5- tetrakisphosphate in homogenates and sub-fractions from normal rat liver and premalignant liver nodules was investigated. The activities of 5-phosphatase, expressed as pmol converted substrate per minute and mg protein, were equal when using the two substrates, and did not differ between normal and nodular homogenates. Subcellular fractions were purified by sequential steps of differential centrifugation and density gradient fractionation procedures. The total phosphatase activity was found to be distributed between cytosol (15%) and membraneous fractions (75%), with most of the enzyme activity residing in the plasma membranes. A doubling of phosphatase specific activity was seen in the nodular low density membrane fraction, containing Golgi apparatus and endosomes, as compared with normal liver. Inositol 1,4,5- trisphosphate 3-kinase activity was found to be exclusively cytosolic. No difference in this enzyme was seen between the two tissue types studied. Vasopressin (0.2 or 2 microM) had no effect either on phosphatase or kinase activity. The compartmentalization of inositol polyphosphate 5-phosphatase activity presents a possible explanation of earlier findings that premalignant liver tissue was able to respond with inositol 1,4,5-trisphosphate, but not inositol 1,3,4,5- tetrakisphosphate formation after agonist stimulation.      

Surveillance of a Ventilated Rack System for Corynebacterium bovis by Sampling Exhaust-Air Manifolds

Corynebacterium bovis causes an opportunistic infection of nude (Foxn1, nu/nu) mice, leading to nude mouse hyperkeratotic dermatitis (scaly skin disease). Enzootic in many nude mouse colonies, C. bovis spreads rapidly to naive nude mice, despite modern husbandry practices, and is very difficult to eradicate. To facilitate rapid detection in support of eradication efforts, we investigated a surveillance method based on quantitative real-time PCR (qPCR) evaluation of swabs collected from the horizontal exhaust manifold (HEM) of an IVC rack system. We first evaluated the efficacy of rack sanitation methods for removing C. bovis DNA from the HEM of racks housing endemic colonies of infected nude mice. Pressurized water used to flush the racks’ air exhaust system followed by a standard rack-washer cycle was ineffective in eliminating C. bovis DNA. Only after autoclaving did all sanitized racks test negative for C. bovis DNA. We then measured the effects of stage of infection (early or established), cage density, and cage location on the rack on time-to-detection at the HEM. Stage of infection significantly affected time-to-detection, independent of cage location. Early infections required 7.3 ± 1.2 d whereas established infections required 1 ± 0 d for detection of C. bovis at the HEM. Cage density influenced the quantity of C. bovis DNA detected but not time-to-detection. The location of the cage on the rack affected the time-to-detection only during early C. bovis infections. We suggest that qPCR swabs of HEM are useful during the routine surveillance of nude mouse colonies for C. bovis infection.Corynebacterium bovis is an opportunistic pathogen of immunodeficient mice and is primarily recognized as the causative agent of hyperkeratotic dermatitis (scaly skin disease) in athymic nude (Foxn1, nu/nu) mice. With a worldwide distribution,^2,10,14 C. bovis causes a clinical illness of short duration followed by what is believed to be lifelong subclinical skin colonization.^2,4 Despite the limited duration of clinical signs, C. bovis is thought to have significant effects on xenograft tumor development, leading to delayed, slowed, or failed xenograft and allograft tumor growth.^7,8Eradication of C. bovis from infected nude mouse colonies has proven to be challenging. Variable success has been demonstrated even with an ideal remediation plan of depopulation, decontamination, and repopulation.^14,16 Additional challenges face institutions that attempt phased decontamination, including efficient horizontal spread of infection despite modern husbandry practices and the ineffectiveness of antibiotics to cure clinically and subclinically infected nude mice.^2,3 In addition, C. bovis is known to produce diffuse environmental contamination throughout facilities by airborne deposition of bacterially populated skin flakes.^1,3 Airborne transmission has even been documented within biosafety cabinets, which should be considered one of the primary methods of cage-to-cage transmission.³Early detection is crucial to maintain nude mice colonies free of C. bovis, given the potential for rapid spread through experimental manipulations, general animal care practices, and extensive equipment and environmental contamination.^3,16 After rapid detection, prompt restriction of animal manipulations and movement would allow time for the identification and removal of infected cage(s), followed by localized decontamination of housing and research equipment. However, colony-based C. bovis detection is neither rapid nor efficient, with ubiquitous soiled-bedding sentinel programs that are based on a paradigm of serologic response, in which soiled bedding typically is gathered every 1 to 2 wk at the time of a cage change and is followed by a traditional 3-mo monitoring interval. Although the monitoring interval might be shortened to enhance surveillance, only a fraction of the cages on an IVC rack can contribute bedding to the sentinel cage at any specific time point, due to volume limitations.^5,9 Therefore, multiple cage-change cycles must occur for all cages on a rack to equally contribute to the sentinel cage. Furthermore, little is known about the duration that immunocompetent mice will carry C. bovis on the haircoat to facilitate detection. To more accurately represent the mice under surveillance, nude mice have been used as soiled-bedding sentinels, with the successful detection of C. bovis within nude mouse colonies.³ However, according to the cited report,³ the inherent limitations of a soiled-bedding sentinel program were not overcome, given that only about half of the cages on a rack contributing soiled bedding during weekly cage changes, with a maximal surveillance interval of 1 mo. Moreover, concerns remain that nude sentinel mice may aid in propagating disease, because the potential for environmental contamination from a C. bovis-infected sentinel nude mouse would mirror that of naturally infected nude mice.⁶ Finally, an additional obstacle to the use of soiled-bedding sentinels is data that suggests that soiled-bedding accumulation points in biologic safety cabinets during cage changing may aid in the horizontal spread of infection.³PCR-based diagnostic surveillance of IVC rack air exhaust for mouse pathogens has yielded some success, through the use of 2 sample collection methods primarily.^5,9,11 Small pieces of filter fabric placed in front of exhaust-air rack filters successfully led to the detection of Helicobacter muridarum, Sendai virus, mouse hepatitis virus, and mouse parvovirus but failed to detect Helicobacter hepaticus and mouse rotavirus in experimentally infected mice.⁵ More recently, direct sampling of a rack system''s horizontal exhaust manifold (HEM, Figure 1) with a sterile swab for PCR has been used successfully to detect the fur mites Myobia musculi and Radfordia affinis from naturally infected mice.⁹ However, in another study using HEM sampling, the mouse pinworm Aspiculuris tetraptera was not detected from naturally infected mice.¹¹ Despite the mixed results, we were interested in using quantitative PCR (qPCR) techniques to evaluate the HEM for C. bovis, given the known distribution of C. bovis-contaminated skin flakes by air currents.³ In addition, this method would preclude entering individual cages for sample collection, subsequently decreasing the potential for cross-contamination between cages. Furthermore, surveillance intervals would not be limited by cage-change frequency, and all cages on an IVC rack could be monitored simultaneously. We also wanted to determine the effects of cage location, mouse cage density, and stage of infection on how quickly C. bovis could be detected by PCR analysis of HEM swabs. To further aid in the practical implementation of this surveillance technique, we also evaluated whether our standard rack-sanitation procedure eliminated C. bovis DNA from the HEM of racks that housed infected nude mice.Open in a separate windowFigure 1.Cut-view illustration of the air supply and exhaust plenums of an IVC rack system (Allentown) viewed from the rear. HEPA-filtered supply air is forced into each cage from the horizontal supply air plenum. Negative pressure draws air from each IVC cage into the horizontal exhaust plenum of the rack. Exhaust air from all cages on the row passes through the row''s HEM to enter the common vertical exhaust plenum flowing in the direction of the red arrow.     

Obturator hip dislocation with intrapelvic migration of the femoral head in Ehlers–Danlos syndrome

Hypermobility of the joints is a cardinal feature of Ehlers-Danlos syndrome (EDS) and joint dislocation as a result of no or minor trauma, is a relatively frequent complication of any form, because of ligamentous laxity [1-3]. Hip dislocations are usually the result of high-energy trauma in young adults, with most being posterior [4-6]. Obturator hip dislocations are relatively rare injuries, accounting for no more than 7% of all traumatic hip dislocations [6, 7]. No obturator hip dislocation as a result of minor insult in EDS has yet been reported. We report an unusual case of obturator hip dislocation by minor insult in EDS, complicated by femoral neck fracture and intrapelvic migration of the femoral head occurring during closed reduction, and also suggest management relevant to this rare injury.     

Induced drug resistance inhibits selection of initiated cells and cancer development

Compounds exerting a mitoinhibitory effect on normal hepatocytes are potent promoters in the resistant hepatocyte model of chemical carcinogenesis in combination with stimulation of regenerative growth by partial hepatectomy or treatment with carbon tetrachloride. 2- Acetylaminofluorene (2-AAF) almost completely inhibits liver cell regeneration after partial hepatectomy, allowing only resistant cells to participate in regenerative growth. After initiation by diethylnitrosamine and promotion with 2-AAF and partial hepatectomy (PH), focal growth of initiated cells generates liver lesions which occupy 40% of the hepatic volume three weeks after PH. In this work the mechanism for the anti promoting effects of phenobarbital and 3- methylcholantrene were investigated as well as their effects on the development of malignant hepatocellular carcinoma in the resistant hepatocyte model. Treatment with phenobarbital or, especially, 3- methylcholanthrene rendered normal rat hepatocytes resistant to the mitoinhibitory effect of 2-AAF. In combination with 2-AAF/PH, 3- methylcholanthrene shortened the regenerative growth period to less than one week. In the Solt-Farber protocol for experimental hepatocarcinogenesis, treatment with phenobarbital or 3- methylcholanthrene during promotion with 2-AAF/PH permitted hepatocytes surrounding the focal lesions to respond with regenerative growth. The foci and surrounding liver grew until the liver/body mass index reached the control value. With phenobarbital treatment the total focal volume was 20% of the liver volume three weeks after PH, whereas the corresponding value in the case of 3-methylcholanthrene was only 1%. Labelling index data supported the conclusion that growth of the liver lesions in the resistant hepatocyte model was dependent on differential inhibition of normal hepatocyte growth by the promoter and that the size of the foci obtained was related to the length of time after PH required to complete liver regeneration. 3-methylcholanthrene induced 2- AAF resistance prevented the development of large persistent nodules and hepatocellular carcinoma while phenobarbital delayed cancer development with several month. The data thus supports the idea that the degree of clonal expansion during promotion determines the size of the population at risk for malignant transformation, as well as the final frequency of carcinomas.      

Obstetric and perinatal outcome of children conceived from cryopreserved embryos

The main purpose of this study was to evaluate the obstetric and neonatal outcome of children conceived from cryopreserved embryos. The medical records of 270 infants (163 singletons, 98 twins and nine triplets) were reviewed and compared with two control populations of children born after in-vitro fertilization (IVF) with fresh embryos and children born after spontaneous pregnancies. The controls were matched according to maternal age, parity, plurality and date of delivery. In the cryopreserved group the gestational age at delivery for singletons was 279 +/- 13 days with birthweight 3476 +/- 616 g; for twins gestational age was 257 +/- 19 days with birthweight 2574 +/- 560 g; for triplets gestational age was 228 +/- 3 days with birthweight 1752 +/- 183 g. The incidence of preterm birth (< 37 weeks gestation) was 5.6% for singletons, 44.9% for twins and 100% for triplets. Seven children had major malformations (2.7%) and perinatal mortality occurred in two children (8/1000). Gestational age at delivery, birthweight, the incidence of malformations and the perinatal mortality were comparable with the two control groups both for singletons and twins. Significantly more singletons in the cryopreserved group were delivered by Caesarean section compared with the spontaneous group. The number of infants with low Apgar score (< 7 at 5 min) and the number of infants admitted to neonatal intensive care units were similar in the cryopreserved and spontaneous groups. In conclusion, the cryopreservation process did not seem to adversely influence fetal development and no increased perinatal risk was found.      

Retinoic acid and retinoid X receptors are differentially expressed in thyroid cancer and thyroid carcinoma cell lines and predict response to treatment with retinoids

Therapy for patients with advanced thyroid carcinoma is limited. Clinical and in vitro studies suggest that some patients with advanced thyroid cancer may respond to therapy with retinoic acid. mRNA expression of the six retinoic acid (RAR) and retinoid X receptor (RXR) isoforms (RARalpha, -beta, -gamma and RXRalpha, -beta, -gamma) was measured in four human thyroid cell lines, and protein expression was subsequently measured in 10 thyroid cancer cell lines. Two isoforms, RARbeta and RXRgamma, were differentially expressed in the four cell lines. Comparison of 10 thyroid tumors and matched normal thyroid tissue confirmed differential tumor expression of RARbeta and RXRgamma and lack of the RXRgamma isoform in normal thyroid tissue. Cell lines expressing both RARbeta and RXRgamma demonstrated significant growth suppression when treated with retinoids, whereas cell lines lacking these isoforms were unaffected. Expression of RARbeta, the isoform associated with suppression of tumor growth in other cancer types, was not affected by treatment with retinoids in the thyroid cancer cell lines. LG346 increased apoptosis and decreased cells in the S-phase in an anaplastic carcinoma cell line, suggesting that this retinoid causes growth suppression of these cells by multiple mechanisms. In summary, we identified the RARbeta and RXRgamma isoform to be differentially expressed in thyroid cancer cell lines and tumor tissue. These isoforms seem to predict response to retinoid therapy in thyroid cancer cell lines.     

Arthrocentesis for the Treatment of Internal Derangement of the Temporomandibular Joint

Objective  

The study aims to evaluate the efficacy of arthrocentesis in the treatment of internal derangement of the temporomandibular joint (TMJ).     

Comparison of cardiovascular risk factors between sri lankans living in kandy and oslo

Background  

South Asians living in western countries are known to have unfavourable cardiovascular risk profiles. Studies indicate migrants are worse off when compared to those living in country of origin. The purpose of this study was to compare selected cardiovascular risk factors between migrant Sri Lankans living in Oslo, Norway and Urban dwellers from Kandy, Sri Lanka.     

Retinoid and thiazolidinedione therapies in melanoma: an analysis of differential response based on nuclear hormone receptor expression

Background  

Metastatic melanoma has a high mortality rate and suboptimal therapeutic options. Molecular targeting may be beneficial using the rexinoid LGD1069, a retinoid × receptor selective agonist, and thiazolidinediones (TZD), PPARγ selective ligands, as novel treatments.