Dermatitis herpetiformis: no evidence of bone disease despite evidence of enteropathy.

The majority of patients with dermatitis herpetiformis (DH) have small intestinal enteropathy that may result in bone loss. The objective of this study was to evaluate bone mineral density (BMD) in DH and to examine whether dietary treatment or degree of the small intestinal lesion correlate with BMD. Twenty-five patients with DH (18 men) were investigated.

Insulin-induced hypoglycemia suppresses plasma parathyroid hormone levels in patients with adrenal insufficiency.

Hypoglycemia has been reported to cause suppression of parathyroid hormone (PTH) levels in serum in normal subjects. It is possible that increasing cortisol levels in response to hypoglycemia was responsible. To examine this possibility the acute PTH response to insulin administration and resulting hypoglycemia was examined in patients with adrenal insufficiency.

Increased bone resorption and failure to respond to antiresorptive therapy in progressive dystrophic calcification.

The aim of this study was to evaluate strategies to halt the progression of severe dystrophic calcification in a patient with progressive systemic sclerosis (PSS) and to monitor serial changes in biochemical markers of bone resorption and indices of calcium (Ca) metabolism in response to therapy. The relationship of bone turnover to the extent of dystrophic calcification was also investigated in a number of additional patients with varying degrees of calcinosis. Serial markers of bone turnover and indices of Ca metabolism were measured over a 3-year period in one patient with PSS and severe dystrophic calcification.

The impact of different glucocorticoid replacement schedules on bone turnover and insulin sensitivity in patients with adrenal insufficiency.

Objective: Optimization of physiological replacement of glucocorticoid in patients with adrenal insufficiency is controversial. The present study was undertaken to compare the relative impact of three different regimes of glucocorticoid replacement in patients with adrenal insufficiency on parameters of bone turnover and insulin sensitivity.

Patients: Six female and three male patients with adrenal insufficiency and 17 female and 14 male control subjects participated.

Use of the gas exchange threshold to noninvasively determine the lactate threshold in patients with cystic fibrosis.

Objective: The anaerobic threshold (AT) is a submaximal index related to endurance exercise performance, which is usually determined by the measurement of blood lactate concentration during an incremental exercise test (lactate threshold [LT]). The LT, and thus the AT, can also be detected noninvasively in normal subjects by means of the gas exchange threshold (GET). This study was undertaken to validate the use of GET in patients with cystic fibrosis (CF) with a wide range of disease severity, and to assess the reproducibility of this index.

Bone density, vitamin D status, and disordered bone remodeling in end-stage chronic liver disease.

Hepatic osteodystrophy occurs in up to 50% of patients with chronic liver disease (CLD). The aim of this study was to determine the relative contribution of increased resorption and decreased formation to hepatic osteodystrophy by measuring biochemical markers. Twenty-seven patients with advanced CLD (14 female, 13 male) were enrolled.

Lactate determination in exercise testing using an electrochemical analyser: with or without blood lysis?

The practical use of lactate electrochemical analysers in exercise testing has not been adequately examined. Initial studies have reported differences in lactate concentration between that measured spectrophotometrically and that measured electrochemically. The study described here was undertaken to compare, using the statistical technique of Bland and Altman (1986), two widely available methods of measuring lactate using lysed and non-lysed blood samples and the lactate thresholds derived from the measured lactate values using a log-log transform technique.

Predicting bone loss following orthotopic liver transplantation.

Background: Hepatic osteodystrophy occurs in the majority of patients with advanced chronic liver disease with the abnormalities in bone metabolism accelerating following orthotopic liver transplantation (OLT).

Aims: To examine changes in bone mineral density (BMD) following OLT and to investigate factors that lead to bone loss.

Methods: Twelve patients had BMD (at both the lumbar spine (LS) and femoral neck (FN)) and biochemical markers measured preoperatively and for 24 months following OLT.

Sol-gel based amperometric biosensor incorporating an osmium redox polymer as mediator for detection of L-lactate.

A novel amperometric biosensor for the determination of lactate was constructed by first immobilizing lactate oxidase and an osmium redox polymer ([Os(bpy)(2)(PVP)(10)Cl]Cl; abbreviated Os-polymer) on the surface of a glassy carbon electrode, followed by coating with a sol-gel film derived from methyltriethoxysilane (MTEOS). The electrooxidation current of this electrode was found to be diffusion controlled. In the presence of lactate, a clear electrocatalytic oxidation wave was observed, and lactate could be determined amperometrically at 400 mV versus Ag AgCl .

Novel instrumentation for real-time monitoring using miniaturized flow systems with integrated biosensors.

A prototype miniaturized Total Chemical Analysis System (muTAS) has been developed and applied to on-line monitoring of glucose and lactate in the core blood of anaesthetized dogs. The system consists of a highly efficient microdialysis sampling interface sited in a small-scale extracorporeal shunt circuit ('MiniShunt'), a silicon machined microflow manifold and integrated biosensor array for glucose and lactate detection with associated computer software for analytical process control. During in-vivo testing the device allowed real-time on-screen monitoring of glucose and lactate with system response times of less than 5 min, made possible by the small dead volume of the microflow system.

In vitro optimisation of a microdialysis system with potential for on-line monitoring of lactate and glucose in biological samples.

The optimisation and evaluation of the microdialysis component of a prototype miniaturised total analysis system for application in the continuous monitoring of lactate and glucose is reported. The complete unit comprises a high efficiency microdialysis sampling system, a miniaturised microflow manifold with an integrated biosensor array, together with the hardware and software necessary for controlling the flow parameters and monitoring the sensor signals. Sampling occurs via a microdialysis shunt probe which is perfused continuously with a physiological buffered saline solution.

Case report: renal osteodystrophy in association with spinal stenosis in achondroplasia.

A 54 year old woman with achondroplasia presented with symptoms of spinal stenosis. Subsequent studies revealed end-stage renal disease with severe renal osteodystrophy that was characterised by radiographs and new bone biomarkers. We speculate that renal osteodystrophy accentuated spinal stenosis, which is a common feature of achondroplasia in adults.

Bone remodeling indices and secondary hyperparathyroidism in celiac disease.

Objectives: To determine the prevalence of hypovitaminosis D and secondary hyperparathyroidism (SHPT) and to assess bone turnover by using markers of bone formation and resorption in celiac disease (CD).

Methods: Forty-three patients with CD were investigated: group 1, newly diagnosed celiacs (n = 19); group 2, treated celiacs responding histologically to a gluten-free diet (n = 16); group 3, refractory celiacs, unresponsive to a gluten-free diet and immunosuppressive therapy (n = 8). Serum was drawn for intact parathyroid hormone (PTH), 25-hydroxyvitamin D [25(OH)D], ionized calcium (Cai), total alkaline phosphatase (AP), and biochemical markers of bone formation: procollagen I carboxyterminal propeptide (PICP) and osteocalcin (Oc).

An intravascular microdialysis sampling system suitable for application in continuous biochemical monitoring of glucose and lactate.

Direct sensor implantation for continuous biochemical monitoring has proved disappointing, but microdialysis sampling devices can serve as a biocompatible patient-sensor interface. We propose a novel "MiniShunt" extracorporeal microdialysis sampling circuit designed to sample core blood, and report the performance of different microdialysis probe membrane types and sizes with pumped and non-pumped blood flow in anaesthetised dogs. Discrete microdialysate and plasma samples collected during glucose and lactate monitoring were analysed with a YSI analyzer and showed microdialysis efficiency (% relative recovery) in excess of 95% for both analytes using fibres of greater than 70 mm2 internal surface area.

Safety and efficacy of increasing wintertime vitamin D and calcium intake by milk fortification.

We studied the safety and efficacy of milk fortified with vitamin D3 and calcium. Over the winter, we conducted a double-blind, placebo-controlled trial of fortified milk (12 micrograms vitamin D3 and 1525 mg calcium per litre) compared to unfortified milk (0.3 micrograms vitamin D3 and 1270 mg calcium per litre) in 102 adults (aged 17-54 years).

Vitamin D supplementation in the elderly: review of safety and effectiveness of different regimes.

Vitamin D deficiency is common in the elderly, especially in countries where effective sunlight or exposure to sunlight is limited. Two regimes for vitamin D supplementation--low-dose daily oral administration and intermittent high-dose administration--were examined with regard to safety and effectiveness. Eleven papers reporting studies in 449 elderly subjects were reviewed.

Serum neuron-specific enolase and immunohistochemical markers of neuroendocrine differentiation in lung cancer.

An enzyme immunoassay for serum neuron-specific enolase (NSE) was evaluated with respect to analytical performance and clinical utility and compared with immunohistochemical evaluation of neuroendocrine differentiation. Values obtained agreed well with values obtained using a radioimmunoassay method giving a correlation coefficient of 0.934.

Dietary chloride and urinary calcium in stone disease.

We studied six patients with renal stone disease, hypercalciuria, cystinuria and/or hyperuricosuria, during variations in dietary Na and Cl intake. Switching between equimolar NaCl and NaHCO3 intakes reduced urinary Ca (UCa) during the NaHCO3 phase, despite steady-state urinary Na. Switching between equimolar NaCl and KCl did not change UCa, despite a sharp fall in UNa.