Evaluation of bone density in girls with precocious and early puberty during treatment with GnRH agonist.

BACKGROUND: Major changes in bone status occur during puberty. Most longitudinal studies have shown no impairment in bone mineral density (BMD) in girls with precocious (PP) and early puberty (EP) during and after GnRH agonist therapy. METHODS: In the present study we evaluated BMD, bone strength (BS) and bone metabolism in 26 girls with PP and with EP before and during treatment with GnRH agonist. BMD was measured by dual energy X-ray absorptiometry and BS was measured using the quantitative high frequency ultrasound technique at baseline, after 6 and 12 months from onset of therapy. Variables were compared with age- and sex-matched values of the same population. Biochemical markers of bone turnover were measured at the same intervals. RESULTS: Mean lumbar spine (LS) and femoral neck (FN) BMD were significantly lower at baseline (LS: p < 0.0001, FN: p < 0.0017) compared with age-matched reference values. Bone strength was significantly lower at the radius (p < 0.0001) and normal at the tibia. A non-significant increase in BMD and a significant increase in BS were observed throughout the first year of therapy with GnRH agonist. Serum bone specific alkaline phosphatase measurements were normal at baseline and remained stable. Urinary deoxypyridinoline\creatinine measurements were significantly higher (p < 0.0001) at baseline and decreased significantly (p < 0.001) during treatment. CONCLUSIONS: Girls with central idiopathic PP and EP have lower BMD and BS for chronological age and increased bone resorption markers. These parameters show a trend of normalization during the first year of therapy with GnRH agonist.

Can dobutamine stress echocardiography induce cardiac troponin elevation?

BACKGROUND: Elevation of cardiac troponin (cTn) is considered specific for myocardial damage. Elevated cTn and echocardiogrpahic documentation of wall motion abnormalities (WMAs) that were recorded after extreme physical effort raise the question whether dobutamine stress echo (DSE), can also induce elevation of troponin. METHODS: we prospective enrolled stable patients (age >18 years) referred to DSE. The exam was performed under standardized conditions. Blood samples for cTnI were obtained at baseline and 18-24 hours after the test. We aimed to compare between the clinical and echocardiographic features of patients with elevated cTnI and those without cTnI elevations. RESULTS: Fifty-seven consecutive patients were included. The average age was 64.4 ± 10.7, 73% of the patients were males, and nearly half of the patients were known to have ischemic heart disease. Two of the patients were excluded due to technical difficulty. No signs of ischemia were recorded in 25 (45.4%). Among the patients with established ischemia on DSE, 12 (22%) had mild ischemia, 13 (23.6%) had moderate and 5 (9%) had severe ischemia. Angiography was performed in 13 (26%) of the patients, of which 7 had PCI and one was referred to bypass surgery. None of the patients had elevated cTnI 18-24 hours after the DSE. CONCLUSIONS: Our results indicate that there is no elevation of cTn despite the occurrence of significant WMAs on DSE. We conclude that cTnI cannot be used as an additional diagnostic tool during pharmacological stress test performed to evaluate the presence and severity of ischemia.

Intraoperative parathormone measurements and postoperative hypocalcemia.

BACKGROUND: Hypocalcemia following thyroid and parathyroid surgery is a well-recognized potential complication. OBJECTIVES: To determine the utility of intraoperative quick parathormone assay in predicting severe hypocalcemia development following parathyroidectomy for a single-gland adenoma causing primary hyperparathyroidism. METHODS: A retrospective cohort study was performed. IO-QPTH values were measured at time 0 (T0) before incision, and 10 (T10) and 30 minutes (T30) following excision of the hyperfunctioning gland. Percent decrease in IO-QPTH at 10 minutes (T10), maximum percent decrease of IO-QPTH value, and lowest actual IO-QPTH value obtained at surgery were used to determine any correlation with the development of postoperative hypocalcemia requiring treatment. RESULTS: Percent decrease in IO-QPTH at 10 minutes, maximum percent decrease in IO-QPTH and lowest IO-QPTH value did not correlate with the lowest postoperative calcium levels measured 18 hours after surgery (r = 0.017, P = 0.860; r = 0.018, P = 0.850; and r = 0.002, P= 0.985 respectively). For the purposes of our analysis, patients were subdivided into three groups. Group 1 comprised 68 patients with normal calcium levels (serum Ca 8.6-10.3 mg/dl), group 2 had 28 patients with hypocalcemia (8.1-8.6 mg/dl), and group 3 included 12 patients with severe hypocalcemia (calcium level < or = 8.0 mg/dl) requiring calcium supplementation due to symptoms of hypocalcemia. There was no difference between the three groups in the lowest IO-QPTH value (P = 0.378), percent decrease in IO-QPTH (P = 0.305) and maximum percent dercrease in IO-QPTH (P = 0.142). CONCLUSIONS: IO-QPTH evaluation was not useful in predicting the group of patients susceptible to develop severe postoperative hypocalcemia.

The association between acetaminophen concentrations in the cerebrospinal fluid and temperature decline in febrile infants.

The objective of this study consisting of a prospective cohort of febrile infants was to describe the correlation between cerebrospinal fluid (CSF) acetaminophen (paracetamol) concentrations and changes in body temperature in febrile infants. Infants, one week to one year of age, with rectal temperature >or=38.0 degrees C, treated with acetaminophen were studied if they underwent a lumbar puncture (LP). Patients received 15 mg/kg of acetaminophen 30 minutes to 4 hours before lumbar puncture was performed. Rectal temperature was documented before acetaminophen administration and at the time of lumbar puncture. Plasma and CSF acetaminophen levels were determined using high-pressure liquid chromatography. Thirty-one infants were studied. In a nonlinear regression, the relationship among acetaminophen concentrations in the CSF, time, and temperature differences is best described by a Lorentzian distribution. The model suggests that a peak effect on temperature is achieved at CSF concentration of 11.9 microg/mL and 182 minutes after acetaminophen administration (P<0.001 and P<0.001, respectively r=0.9 adjusted r square=0.78). Temperature decrement in young febrile infants, treated with acetaminophen, correlates with time and acetaminophen concentrations in the CSF. High concentrations of acetaminophen in the CSF, exceeding a certain level, are not associated with greater temperature decrement.

Magnesium and C-reactive protein in heart failure: an anti-inflammatory effect of magnesium administration?

BACKGROUND: Little is known about the relationship between serum magnesium (Mg) and C-reactive protein (CRP) in heart failure (HF). AIM OF THE STUDY: To investigate the relationship, if any, between serum Mg and CRP in HF patients and, concomitantly, to test a hypothesis that Mg supplementation might affect serum CRP levels. METHODS: Serum Mg and CRP were evaluated in 68 patients with chronic systolic HF leading to hospital admission and 65 patients requiring hospitalization for other causes. Following 5 weeks, serum Mg, CRP and intracellular Mg were reevaluated in 17 HF patients after administration of oral Mg citrate 300 mg/day (group A), and 18 untreated HF patients (group B). In order to obtain Gaussian distribution, logarithmic transformation of CRP was performed. RESULTS: Inverse correlation was found between serum Mg and log CRP (r = -0.28, P = 0.002). Compared to controls, patients with HF demonstrated higher baseline CRP levels, independent of coexisting conditions, and lower serum Mg values. Following Mg treatment, log CRP decreased from 1.4 +/- 0.4 to 0.8 +/- 0.3 in group A (P < 0.001). No significant changes in log CRP were demonstrable in group B. Serum Mg (mmol/l) rose significantly in group A (0.74 +/- 0.04-0.88 +/- 0.08, P < 0.001), and to a lesser extent in group B (0.82 +/- 0.08-0.88 +/- 0.08, P = 0.04). Intracellular Mg significantly increased only in Mg-treated group A (P = 0.01). CONCLUSIONS: Oral Mg supplementation to HF patients significantly attenuates blood levels of CRP, a biomarker of inflammation. Targeting the inflammatory cascade by Mg administration might prove a useful tool for improving the prognosis in HF.

Quick parathormone assay in the surgical management of hyperparathyroidism.

BACKGROUND: Among the various new technologies in the field of parathyroid surgery is intraoperative quick parathormone measurements. OBJECTIVES: To evaluate the contribution of QPTH measurements during parathyroidectomy to the achievement of higher success rates. METHODS: QPTH assay using Immulite Turbo Intact PTH was measured in 32 patients undergoing parathyroidectomy: 30 for primary and 2 for secondary hyperparathyroidism. QPTH levels were measured at time 0 minutes (before incision) and at 10, 20, and 30 minutes after excision of the hyperfunctioning gland. Only a drop of 60% or more from the 0' level was considered to be a positive result. RESULTS: The mean QPTH level at time 0' for PHPT patients was 38.12 +/- 25.15 pmol/L (range 9.1-118 pmol/L). At 10 minutes post-excision of the hyperfunctioning gland (or glands), QPTH dropped by a mean of 73.80% to 9.89 +/- 18.78 pmol/L. CONCLUSIONS: Intraoperative QPTH level measurement is helpful in parathyroid surgery. A drop of 60% or more from 0' level indicates a successful procedure, and further exploration should be avoided.