Direct Radioimmunoassay of Nuclear 3,5,3′ Triiodothyronine in Rat Anterior Pituitary

Previous tracer studies have suggested that 5′-monodeiodination of l-thyroxine (T₄) in anterior pituitary may contribute a substantial portion of specifically bound nuclear 3,5,3′ l-triiodothyronine (T₃) in this tissue in rats. To evaluate this possibility, a radioimmunoassay for nuclear T₃ in individual anterior pituitaries was developed. Animals received [¹²⁵I]T₃ 60 min before removal of the anterior pituitary and isolation of the nuclei by differential centrifugation. This allowed calculation of the nuclear:serum T₃ ratio and comparison of expected with measured T₃. T₃ was extracted in ethanol, dried, and reconstituted in assay buffer. In untreated hypothyroid rats, anterior pituitary nuclear T₃ was 0.18 ± 0.06 pg/μg DNA which was 0.13 pg/μg DNA greater than expected from the serum T₃ concentration and the pituitary nuclear:serum [¹²⁵I]T₃ ratio. In 10 hypothyroid rats given a single bolus of 400 ng T₃/100 g body wt., the nuclear T₃ by radioimmunoassay was 1.0 ± 0.06 pg/μg DNA, whereas that expected from the T₃ specific activity calculations was 0.85 pg/μg DNA (P < 0.025). Serum T₄ concentrations in these rats were < 0.25 μg/dl but the nuclear T₃ derived from as little as 0.2 μg/dl T₄ could explain a large portion of these small discrepancies between observed and measured nuclear T₃. In 29 normal rats, anterior pituitary nuclear T₃ was 0.63±0.04 pg/μg DNA, whereas that expected from the serum T₃ concentration (55±2 ng/dl) was 0.23±0.02 pg/μg DNA (P < 0.001). Total pituitary T₃ based on this measurement was 92±6 pg. Because the maximal nuclear binding capacity for T₃ in rat anterior pituitary is 0.77 pg/μg DNA, these results suggest there is 82% occupancy of these nuclear receptors. The requirement for normal serum concentrations of both T₄ and T₃ to achieve normal nuclear T₃ saturation in anterior pituitary is in marked contrast to the situation in liver, kidney, and heart muscle which appear to require only a normal serum T₃. As a consequence, the anterior pituitary can monitor both serum T₄ and T₃ and respond appropriately to changes in their concentrations.     

Surgical pathology of native valve endocarditis in 310 specimens from 287 patients (1985–2004)

BackgroundFew large studies have documented the clinical and pathologic features of native valve endocarditis (NVE) independently from prosthetic valve endocarditis (PVE).MethodsA retrospective study of medical records of all patients undergoing operation for NVE at Mayo Clinic in Rochester, MN (1985–2004), was performed. Medical records were reviewed from 287 patients for demographics, infecting organism, and comorbidities. Microscopic slides from 310 valves were reviewed for features of infection.ResultsThe study cohort included 287 patients, with age ranging from 9 to 87 years (mean, 54), yielding 310 valves. Most (73%) were from men, and 84% were regurgitant. Risk factors included bicuspid aortic valve (23%), dental manipulation (20%), mitral valve prolapse (18%), diabetes mellitus (16%), and others (< 5% each); in 15%, no risk factor was identified. The four most commonly identified organisms were viridans group streptococci (28%), Staphylococcus aureus (18%), enterococci (9%), and coagulase-negative staphylococci (8%). NVE was histologically active in 58% and healed in 42%, and affected left-sided valves in 94%. It was associated with embolization in 29%, acute heart failure in 29%, and annular abscess in 18%. Men accounted for a higher percentage of aortic NVE than mitral NVE (82% versus 63%, respectively; P=.001). Among 126 valves with active endocarditis, 25% had no microorganisms identified histologically.ConclusionNVE affected men nearly three times as frequently as women. Diabetes mellitus emerged as a prevalent (and previously underrecognized) risk factor for NVE. The most common infecting organisms were streptococci and staphylococci. Microorganisms were identified histologically in the majority of active endocarditis cases.     

Periodontal diseases and risk of oral cancer in Southern India: Results from the HeNCe Life study

Some studies suggest that periodontal diseases increase the risk of oral cancer, but contradictory results also exist. Inadequate control of confounders, including life course exposures, may have influenced prior findings. We estimate the extent to which high levels of periodontal diseases, measured by gingival inflammation and recession, are associated with oral cancer risk using a comprehensive subset of potential confounders and applying a stringent adjustment approach. In a hospital‐based case‐control study, incident oral cancer cases (N = 350) were recruited from two major referral hospitals in Kerala, South India, from 2008 to 2012. Controls (N = 371), frequency‐matched by age and sex, were recruited from clinics at the same hospitals. Structured interviews collected information on several domains of exposure via a detailed life course questionnaire. Periodontal diseases, as measured by gingival inflammation and gingival recession, were evaluated visually by qualified dentists following a detailed protocol. The relationship between periodontal diseases and oral cancer risk was assessed by unconditional logistic regression using a stringent empirical selection of potential confounders corresponding to a 1% change‐in‐estimates. Generalized gingival recession was significantly associated with oral cancer risk (Odds Ratio = 1.83, 95% Confidence Interval: 1.10–3.04). No significant association was observed between gingival inflammation and oral cancer. Our findings support the hypothesis that high levels of periodontal diseases increase the risk of oral cancer.     

Immunomodulatory effects of the tobacco-specific carcinogen,NNK, on alveolar macrophages

Lung cancer is strongly associated with cigarette smoking. More than 20 lung carcinogens have been identified in cigarette smoke and one of the most abundant is 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). We hypothesized that NNK modulates alveolar macrophage (AM) mediator production, thus contributing to carcinogenesis. An AM cell line, NR8383, was treated with [3H]NNK and lipopolysaccharide (LPS), and NNK metabolites released in supernatants were analysed by high-performance liquid chromatography (HPLC). NNK was metabolized by carbonyl reduction to 4-(methylnitrosamino)-1-(3-pyridyl)-1-butan-1-ol (NNAL) or activated by alpha-carbon hydroxylation. AMs were also treated with NNK (100-1000 micro M), with and without LPS, for different periods of time (6-72 h), and mediators released in supernatants were quantified by enzyme-linked immunosorbent assay (ELISA) or the Griess reaction. NNK inhibited (in a concentration-dependent manner) AM production of tumour necrosis factor (TNF), macrophage inflammatory protein-1alpha (MIP-1alpha), interleukin (IL)-12 and nitric oxide (NO), whereas IL-10 production was increased. Cyclooxygenase inhibitors - NS-398 and indomethacin - and anti-prostaglandin E2 (anti-PGE2) antibody abrogated the NNK-inhibitory effect on MIP-1alpha production by AM. NNK stimulated the release of PGE2, and exogenous PGE2 inhibited AM MIP-1alpha production, suggesting that the NNK immunomodulatory effect may be mediated by PGE2 production. Thus, in addition to its carcinogenic effects, NNK may contribute to the lung immunosuppression observed in tobacco smokers.     

Therapist effectiveness: Implications for accountability and patient care

Abstract

Significant therapist variability has been demonstrated in both psychotherapy outcomes and process (e.g., the working alliance). In an attempt to provide prevalence estimates of “effective” and “harmful” therapists, the outcomes of 6960 patients seen by 696 therapists in the context of naturalistic treatment were analyzed across multiple symptom and functioning domains. Therapists were defined based on whether their average client reliably improved, worsened, or neither improved nor worsened. Results varied by domain with the widespread pervasiveness of unclassifiable/ineffective and harmful therapists ranging from 33 to 65%. Harmful therapists demonstrated large, negative treatment effect sizes (d=?0.91 to ?1.49) while effective therapists demonstrated large, positive treatment effect sizes (d=1.00 to 1.52). Therapist domain-specific effectiveness correlated poorly across domains, suggesting that therapist competencies may be domain or disorder specific, rather than reflecting a core attribute or underlying therapeutic skill construct. Public policy and clinical implications of these findings are discussed, including the importance of integrating benchmarked outcome measurement into both routine care and training.