The role of TGF-ß1 in osteoarthritis of the temporomandibular joint in two genetic mouse models.

OBJECTIVE: The objective of this study is to elucidate osteoarthritis (OA) progression in the temporomandibular joint (TMJ) in two genetic mouse models by assessing the expression of an identified inflammatory marker associated with OA, viz., Tgf-ß1. This study provides mechanistic insight into disease progression based on the temporal expression of Tgf-ß1 in the TMJ. DESIGN: The two models included the heterozygous chondrodysplasia mutation (cho/+), a Coll11a1 mutation, and the autosomal semidominant disproportionate micromelia mutation (Dmm/+), a Col2a1 mutation. To determine OA status histologically, TMJs from each mutant were fixed, sectioned and stained with Safranin O to identify proteoglycans in condylar cartilage and counterstained with Fast Green. The extent of staining and onset of OA-like changes were quantified using the Modified Mankin scoring system. Using immunofluorescence, selected tissue sections of each genotype were stained for the presence of Tgf-ß1, HtrA1, and p-Smad2. RESULTS: The results revealed Mankin scores of the condylar cartilage of both mutants that are consistent with established histopathological changes of OA. Immunofluorescence indicated increased expression of all three molecular markers and their co-localization within condylar chondrocytes of both mutants. CONCLUSIONS: Elevated Tgf-ß1 expression in mutant condylar cartilage supports the hypothesis that this inflammatory mediator is mechanistically involved in the pathogenesis of TMJ OA. Compared to basal expression in control TMJs, the positive co-localized staining for Tgf-ß1, HtrA1, and p-Smad2 in both mutants demonstrates involvement of these molecules in the degradative pathway of OA. Tgf-ß1 therefore is a potential target for further study for the diagnosis and treatment of TMJ OA.

Possible serotonin syndrome with carbidopa-levodopa and linezolid.

WHAT IS KNOWN AND OBJECTIVE: Serotonin syndrome (SS) can occur when linezolid is combined with other serotonergic agents. CASE DESCRIPTION: We report a case of possible SS in an elderly patient receiving linezolid in combination with carbidopa-levodopa (CL). WHAT IS NEW AND CONCLUSION: Although certain classes of agents are commonly reported as causing SS among patients receiving linezolid, there are no specific case reports detailing this reaction with CL. Linezolid combined with CL should generally be avoided; however, if linezolid must be used, discontinuation of other agents with serotonergic activity is recommended with careful monitoring for signs and symptoms of SS.

A retrospective analysis of the effect of human milk on prevention of necrotizing enterocolitis and postnatal growth.

OBJECTIVE: The objective of this study is to determine whether the use of donor human milk (DHM) in very low birth weight (VLBW, ⩽1500 g) neonates in a large neonatal intensive care unit (NICU) affected the rate of necrotizing enterocolitis (NEC) or impacted growth. STUDY DESIGN: This was a retrospective chart review of 550 VLBW neonates following the introduction of DHM as the preferred diet if maternal breast milk (MBM) was not available. Demographics, growth parameters, incidence of NEC or death and days of DHM or MBM were extracted from charts. RESULT: Compared with infants who received human milk (HM) on fewer than 50% of hospital days, neonates who received HM on ⩾50% of hospital days had equivalent growth outcomes but lower rates of NEC (NEC 3.4 vs 13.5%, P<0.001) and mortality (1.0 vs 4.2%, P=0.017). Growth and NEC rates were inversely correlated with the duration of exposure to HM. CONCLUSION: HM should always be the diet of choice in preterm infants. DHM is a safe alternative, if MBM is not available. Although the use of HM is associated with lower rates of NEC, growth rates were significantly lower in infants with significant HM intake. The decline in growth rates following the introduction of DHM should draw attention to optimize fortification of all HM feedings.

Evaluation of risk factors for vancomycin-resistant Enterococcus bacteremia among previously colonized hematopoietic stem cell transplant patients.

BACKGROUND: Hematopoietic stem cell transplantation (HSCT) recipients colonized with vancomycin-resistant Enterococcus (VRE) may have an increased risk of developing VRE bacteremia. Identification of risk factors for the development of subsequent VRE bacteremia among colonized HSCT recipients is necessary to predict which patients may benefit the most from receiving anti-VRE antibiotic therapy as part of an initial antimicrobial regimen when gram-positive bacteremia is suspected. METHODS: This study was a retrospective chart review conducted from May 2008 to May 2011. Adult HSCT patients admitted to the hospital found to have positive VRE surveillance cultures were included. A multivariate analysis was completed to identify risk factors for the development of VRE bacteremia in the study population. RESULTS: Of 152 patients, 19 (13%) patients developed subsequent VRE bacteremia. Risk factors identified for patients with current VRE colonization for VRE bacteremia were the utilization of vancomycin subsequent to VRE surveillance culture positivity (P = 0.017), prolonged duration of neutropenia (P = 0.001), immunosuppression (P < 0.001), and timing of first VRE surveillance screen positivity at week 1 (P = 0.005). A history of VRE colonization on a prior admission was not an independent risk factor for bacteremia in HSCT patients (P = 1.0). HSCT patients with VRE bacteremia had a 30-day all-cause inpatient mortality rate of 29% (P = 0.001). CONCLUSION: HSCT patients receiving immunosuppressive therapy, who have been exposed to vancomycin subsequent to surveillance culture positivity, have had prolonged neutropenia of >30 days, or first surveillance culture positive at week 1 of admission are potential candidates for early implementation of anti-VRE therapy when a gram-positive bacteremia is suspected.

A therapeutic target for hormone-independent estrogen receptor-positive breast cancers.

BACKGROUND: The action of the steroid hormone estradiol (E2) is mediated via interaction with a specific receptor (ER) that initiates a series of events downstream, leading to the modulation of hormone-responsive genes and cell proliferation. Antihormones also bind, but do not confer the active configuration to ER, thereby, blocking the transmission of E2-ER-initiated signals for cell proliferation. Although these compounds qualify for successful therapy of ER-positive [ER (+)] breast cancer patients, only a fraction of patients responds to antihormone treatment. In this study, the functional status of ER is determined to identify alternative targets for therapy of antihormone-resistant ER (+) breast cancers. METHOD: The interaction of ER with a specific DNA sequence, designated as E2 response element (ERE), was targeted to assess the functional state of ER. ER-ERE complex formation was measured by electrophoretic mobility shift assay (EMSA) and by a newly developed technique, based on the preferential binding of DNA-protein complex to a nitrocellulose membrane (NMBA) that measures both total and functional fraction of ER. RESULTS: The NMBA assay identified functional variants of ER among ER (+) breast cancer cell lines and breast tumor biopsy specimens. ER of (21PT) cells did not bind E2 and these cells were tamoxifen (TAM) resistant. However 21PT cells were sensitive to a calmodulin (CaM) antagonist, W7, that blocked ERE-ER complex formation. CONCLUSIONS: ER variants of the 21PT type were detected among breast cancer biopsy specimens, emphasizing the significance of an alternative therapeutic target for TAM-resistant ER (+) human breast cancers with compounds such as W7.

Calmodulin is essential for estrogen receptor interaction with its motif and activation of responsive promoter.

Calmodulin (CaM) has been reported to have affinity for the estrogen receptor (ER). Observations reported here reveal a direct physical interaction between purified CaM and ER. This direct ER-CaM interaction may be an initial event preceding the assembly of ER plus auxiliary proteins into the active ER complex with its DNA motif, the estrogen response element. We demonstrate that CaM is an integral component of this complex by using a system reconstituted from purified ER and nuclear extract from ER-negative breast cancer cells and also with ER-depleted nuclear extract of an ER-positive breast cancer cell line. Although CaM is essential for formation of this complex, it is not sufficient, suggesting roles also of auxiliary proteins. CaM also is functionally required for activation of an ER-responsive promoter, in the 17beta-estradiol-ER pathway of hormone action and regulation of 17beta-estradiol-responsive gene expression that is associated with proliferation of mammary epithelial cells.

Effect of alcohol on the plasma cAMP response to glucagon.

Prior studies indicated that acute ethanol feeding induced a decrease in adrenergic sensitivity as measured by the plasma cAMP response to isoproterenol. In this report we show that two hours after acute ethanol ingestion the plasma cyclic AMP levels were increased 8.5 fold 6 minutes after glucagon injection. Saline controls showed a 35 fold increase in plasma cAMP levels after glucagon injection. It is suggested that the decreased response caused by ethanol may be due to a decrease in the sensitivity of glucagon receptors.

Reduced adrenergic sensitivity in vivo in acute ethanol-fed rats.

Prior studies indicate ethanol feeding induces adrenergic subsensitivity in vitro, as measured by cyclic adenosine monophosphate (cAMP) response of tissues to norepinephrine (NE). In this report we show acute ethanol feeding induces a depressed level of adrenergic sensitivity in vivo, as measured by plasma cAMP response to isoproterenol. Two hours after intragastric feeding of ethanol (6 gm/kg) to rats, there was a decrease in plasma cAMP response to intravenous isoproterenol, compared to dextrose controls. This decrease was the same in animals with blood ethanol levels averaging 68 mg/dl or 193 mg/dl. This data is consistent with the hypothesis that ethanol induces adrenergic subsensitivity.

Differential stabilities of soil enzymes. Assay and properties of phosphatase and arylsulphatase.

Methods have been refined for the assay of phosphatase and arylsulphatase activities in soil, based on the chromogenic p-nitrophenyl ester substrates. Basic assay conditions have been defined, and pH optima and kinetic parameters have been determined. The enzymes follow Michaelis-Menten kinetics; this conclusion is based on three methods of analysis of data determined over a wide range of substrate concentrations. The enzyme activities are very stable to storage of wet soil for up to 4 weeks at soil temperatures and above. For example, phosphatase had a half-life of approximately 2 weeks at 50 degrees C; arylsulphatase was rather less stable. Both enzymes retained 80% of activity after incubation with pronase for 1 week at 25 degrees C. On the basis of this work and studies on other soil enzymes, it is concluded that remarkable stability is a general feature of soil enzymes.