Determination of 5-methyltetrahydrofolic acid in human serum by stable-isotope dilution high-performance liquid chromatography-mass spectrometry.

The need for specific and sensitive methods for the determination of distinct serum folates is of high priority in clinical research settings. A stable-isotope liquid chromatography-mass spectrometry (LC/ESI-MS) assay was developed for the quantitative determination of the monoglutamyl form of 5-methyltetrahydrofolic acid (5-MTHFA) in human serum. Serum samples (0.

Cytopathology induced by mercuric chloride and methylmercury in cultured renal cells of the Atlantic spotted dolphin (Stenella plagiodon).

High mercury concentrations have been reported in various tissues of cetaceans, but the toxicological effects of mercury on cetaceans remain unclear. In vivo study is difficult due to the endangered status of these marine mammals and co-exposure to both mercury and selenium (antagonist of mercury) in the oceanic environment. The present data are the first ultrastructural information on dolphin renal cells exposed to mercury in vitro.

Protective effects of selenium against mercury toxicity in cultured Atlantic spotted dolphin (Stenella plagiodon) renal cells.

Marine mammals are known for their low susceptibility to mercury toxicity, and selenium may play a role in this protection against mercury intoxication. To gain insight into mechanisms by which selenium might inhibit mercury toxicity in cetacean cells, we investigated the effects of sodium selenite on cell proliferation and cell death (including apoptosis, oncosis, and necrosis) of control and mercuric chloride-treated Atlantic spotted dolphin renal cells (Sp1K cells). Concurrent exposure to 80 microM Na2SeO3 provided full protection against the decrease in cell proliferation induced by 20 microM HgCl2.

Reduction of colonic mucus by repeated short-term stress enhances experimental colitis in rats.

The role of stress in inflammatory bowel disease remains debated and few studies have tested the role of stress in conjunction with experimental animal models of colitis. In this investigation we tested the hypothesis that cold-restraint stress would adversely effect the severity of 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis in rats, and examined mechanisms for the response. Results indicated that increasing intermittent prior exposures to stress significantly enhanced TNBS-induced colitis severity.

Reinforcement of occupational history taking: a success story.

Background: This article describes the results of a retrospective study of 3 classes of medical students who participated in a targeted occupational and environmental health curriculum at the University of Connecticut School of Medicine.

Purpose: We wanted to determine if targeted focused curricular interventions which integrated occupational and environmental health principles into routine history taking would result in increased scores on the number of questions posed during the Clinical Skills Assessment Program in the 4th year.

Methods: We analyzed Clinical Skills Assessment Program questions for 3 graduating medical school classes from 1997 to 1999.

The impact of a curriculum renewal project on students' performances on a fourth-year clinical skills assessment.

Purpose: To study the performances of three consecutive classes of medical students on a fourth-year clinical skills assessment that remained constant during a curriculum renewal project that involved earlier clinical work, more ambulatory training, and an emphasis on lifelong learning.

Method: Three classes were involved: 83 baseline students (class of 1997) educated in the old curriculum, 77 transitional students (class of 1998) exposed to some curricular change, and 88 renewal students (class of 1999) in the first year of full curricular change. Each class completed a fourth-year assessment, during which students performed a focused history and physical examination on 14 standardized patients.

The variability of serial fMRI data: correlation between a visual and a motor task.

We investigated whether the intersession variability of serial fMRI studies correlates between two activation modalities, i.e. a standardized visual and a standardized motor task.

Analysis of factors influencing the comparison of homocysteine values between the Third National Health and Nutrition Examination Survey (NHANES) and NHANES 1999+.

Two important changes occurred in the time between the Third National Health and Nutrition Examination Survey (NHANES III) (1991-1994) and the later survey (NHANES 1999+) regarding total homocysteine (tHcy), i.e., a change in matrix from serum to plasma and a change in analytical methods.

Spontaneous thyroid-containing teratoma associated with impaired development in the African clawed frog, Xenopus laevis.

Teratomas are rare in amphibians and the neoplasm described here, which had a significant thyroid carcinoma component, is the first tumour of this type to be reported in Xenopus laevis. The thyroid component contained moderately to well-differentiated acinar glands showing much hyperplasia, dysplasia, and reduced and distorted colloid reservoirs. Cartilaginous, neural, muscular, mesenchymal and gut-like epithelial components were also observed in this ventral mediastinal neoplasm, indicating aberrant proliferation from all three germ layers.

Functional and ultrastructural cell pathology induced by fuel oil in cultured dolphin renal cells.

Investigations were undertaken to elucidate in a marine mammal renal cell culture system the toxicity and some of the mechanisms of cytopathology in a standardized preparation following exposure to No. 1 fuel oil. Cell survivability of a cultured SP1K renal cell line from the Atlantic spotted dolphin Stenella plagiodon was reduced in a dose-dependent manner after a 12-h exposure to fuel oil.

Functional morphology of the equine pelvic flexure and its role in disease. A review.

The hindgut is the major site in the horse for nutrient digestion and absorption. Most of this activity occurs in the large intestinal compartments, i.e.

Negative inotropic effects of recombinant interleukin 2 in patients without left ventricular dysfunction.

Unlabelled: Experimental data have shown that rIL2 has negative inotropic properties. This has not been investigated in humans with normal left ventricular function. Seventeen consecutive renal cell carcinoma patients who received rIL2 therapy because of dissemination were analyzed before and after treatment with a low dose of rIL2 subcutaneously.

Ultrastructure of the horse tongue: further observations on the lingual integumentary architecture.

This investigation examined primarily epidermal specializations of the adult horse tongue by light, scanning and transmission electron microscopy. Samples were collected from seven regions of the normal tongue of various breeds of horse. The filiform papillae, present on the dorsal and lateral aspects but not the ventral aspect of the tongue, were short, slender and finger-like structures with variable-shaped terminae.

Teaching patient wellness to first-year medical students: the impact on future ability to perform the history of present illness.

Objectives: Curriculum innovations to improve clinical skills have been implemented at many American medical schools. A current curricular change at the University of Connecticut School of Medicine involves teaching wellness to students in the first year rather than the more traditional focus on disease processes. It is unknown, however, if focusing on wellness detracts from students' future ability to perform the history of present illness (HPI) which requires students to focus on disease processes.

Ultrastructural morphology of the gill of the hybrid striped bass (Morone saxatilis x M. chrysops).

The fine structure of the principal cell types found in the gill filaments and secondary, respiratory lamellae of the hybrid striped bass (Morone saxatilis x M. chrysops) was studied by transmission electron microscopy. Most of the cell types generally resembled those observed at this level of resolution in other euryhyaline, teleostean species, and the mucus cells, epithelial cells, and cartilage cells were non-distinctive.

Decision making of clinical teams: communication patterns and diagnostic error.

This study examined the discussion of information among mixed-status clinical teams while constructing differential diagnoses. Twenty-four ad hoc teams, each consisting of a resident, an intern, and a third-year medical student, were given two hypothetical patient cases to discuss and diagnose. Prior to discussion, team members individually viewed different versions of a videotaped interview with a "patient" (trained actor).

Photoreceptor ultrastructure of the amphipod, Cyamus ceti (Linné, 1758), an ectoparasite of bowhead, right and gray whales.

Light and electron microscopic findings are presented for the first time on a species of amphipod whale louse, Cyamus ceti, with reference to the paired photoreceptor structures of the head. Whale lice are crustacean ectoparasites of large, slow moving whales. Twenty-two known species parasitize mainly baleens but also toothed whales.

Comparison of serum and plasma methylmalonic acid measurements in 13 laboratories: An international study.

Background: Detection of cobalamin deficiency is increasingly important, and methylmalonic acid (MMA) appears to be a useful marker. Information on interlaboratory variation and on methodological differences for MMA in serum and plasma is limited.

Methods: Using gas chromatography/mass spectrometry, 13 laboratories participated in a 2-day analysis of 8 serum and 11 EDTA-plasma specimens.

Comparative effects of glimepiride and glibenclamide on blood glucose, C-peptide and insulin concentrations in the fasting and postprandial state in normal man.

A single-center, randomised, placebo- controlled, cross-over study was conducted to characterize the new sulfonylurea glimepiride and to compare its profile of action with the second generation sulfonylurea glibenclamide. The total duration of each experiment was 5 hours. At zero time an i.

Comparison of plasma total homocysteine measurements in 14 laboratories: an international study.

Background: Information on interlaboratory variation and especially on methodological differences for plasma total homocysteine is lacking.

Methods: We studied 14 laboratories that used eight different method types: HPLC with electrochemical detection (HPLC-ED); HPLC with fluorescence detection (HPLC-FD) further subdivided by type of reducing/derivatizing agent; gas chromatography/mass spectrometry (GC/MS); enzyme immunoassay (EIA); and fluorescence polarization immunoassay (FPIA). Three of these laboratories used two methods.

Angiotensin induces inflammatory activation of human vascular smooth muscle cells.

Multiple data suggest that the renin-angiotensin system contributes to the pathogenesis of atherosclerosis. The atherogenic effect of the renin-angiotensin system can only in part be explained by the influence of its effector angiotensin II on blood pressure, smooth muscle cell (SMC) growth, or antifibrinolytic activity. Because chronic inflammation of the vessel wall is a hallmark of atherosclerosis, we hypothesized that angiotensin II may elicit inflammatory signals in vascular SMCs.

Long-term application of extracorporeal photochemotherapy in severe atopic dermatitis.

Background: Extracorporeal photochemotherapy (ECP) using UVA irradiation of enriched leukocytes in the presence of methoxsalen as a photoactivatable substrate has been employed for the treatment of several immunologically mediated disorders.

Objective: Our purpose was to determine the efficacy and safety of long-term ECP in the treatment of severe atopic dermatitis.

Methods: Fourteen patients with severe recalcitrant atopic dermatitis were treated with ECP in an open clinical trial at 2-week intervals.