On death and dying

Drug-induced hepatotoxicity.

Given the recent spate of reports of vitamin D deficiency, there is a need to reexamine our understanding of natural and other sources of vitamin D, as well as mechanisms whereby vitamin D synthesis and intake can be optimized. This stateof-the-art report from the Drug and Therapeutics Committee of the Lawson Wilkins Pediatric Endocrine Society was aimed to perform this task and also reviews recommendations for sun exposure and vitamin D intake and possible caveats associated with these recommendations. Pediatrics 2008;122:398‐417

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Vitamin D Deficiency in Children and Its Management: Review of Current Knowledge and Recommendations

The amniotic membrane in ophthalmology

BACKGROUND
Hypovitaminosis D and a low calcium intake contribute to increased parathyroid function in elderly persons. Calcium and vitamin D supplements reduce this secondary hyperparathyroidism, but whether such supplements reduce the risk of hip fractures among elderly people is not known.


METHODS
We studied the effects of supplementation with vitamin D3 (cholecalciferol) and calcium on the frequency of hip fractures and other nonvertebral fractures, identified radiologically, in 3270 healthy ambulatory women (mean [+/- SD] age, 84 +/- 6 years). Each day for 18 months, 1634 women received tricalcium phosphate (containing 1.2 g of elemental calcium) and 20 micrograms (800 IU) of vitamin D3, and 1636 women received a double placebo. We measured serial serum parathyroid hormone and 25-hydroxyvitamin D (25(OH)D) concentrations in 142 women and determined the femoral bone mineral density at base line and after 18 months in 56 women.


RESULTS
Among the women who completed the 18-month study, the number of hip fractures was 43 percent lower (P = 0.043) and the total number of nonvertebral fractures was 32 percent lower (P = 0.015) among the women treated with vitamin D3 and calcium than among those who received placebo. The results of analyses according to active treatment and according to intention to treat were similar. In the vitamin D3-calcium group, the mean serum parathyroid hormone concentration had decreased by 44 percent from the base-line value at 18 months (P < 0.001) and the serum 25(OH)D concentration had increased by 162 percent over the base-line value (P < 0.001). The bone density of the proximal femur increased 2.7 percent in the vitamin D3-calcium group and decreased 4.6 percent in the placebo group (P < 0.001).


CONCLUSIONS
Supplementation with vitamin D3 and calcium reduces the risk of hip fractures and other nonvertebral fractures among elderly women.

Vitamin D and Calcium to Prevent Hip Fractures in Elderly Women

The terms extended donor or expanded donor mean changes in donor acceptability criteria. In almost all cases, the negative connotations of these terms cannot be justified. Factors considered to affect donor or organ acceptability have changed with time, after showing that they did not negatively affect graft or patient survival per se or when the adequate measures had been adopted. There is no age limit to be an organ donor. Kidney and liver transplantation from donors older than 65 years can have excellent graft and patient actuarial survival and graft function. Using these donors can be from an epidemiological point of view the most important factor to esablish the final number of cadaveric liver and kidney transplantations. Organs with broad structural parenchyma lesion with preserved functional reserve and organs with reversible functional impairment can be safely transplanted. Bacterial and fungal donor infection with the adequate antibiotic treatment of donor and/or recipient prevents infection in the latter. The organs, including the liver, from donors with infection by the hepatitis B and C viruses can be safely transplanted to recipients with infection by the same viruses, respectively. Poisoned donors and non-heart-beating donors, grafts from transplant recipients, reuse of grafts, domino transplant and splitting of one liver for two recipients can be an important and safe source of organs for transplantation.

Extended criteria for organ acceptance. Strategies for achieving organ safety and for increasing organ pool.

Some studies have suggested that the use of sunscreens to prevent skin cancer may put the population at risk of vitamin D deficiency. We followed 24 sunscreen users and 19 controls over 2 years, including two summers, two winters and a basal period (winter). Vitamin D, parathormone and bone biological markers were evaluated each season. Mean levels of 25-hydroxyvitamin D rose in summer, with the increments being significantly higher for the second year in the control group. Levels decreased in winter in both groups, and were significantly lower in sunscreen users. We did not observe any significant change in parathormone, tartrate resistant phosphatase, total alkaline phosphatase, osteocalcin, urine hydroxyproline or urine calcium. Clinically prescribed sunscreen creams (sun protection factor 15) caused a minor decrease in 25-hydroxyvitamin D levels, which did not induce secondary hyperparathyroidism or an increment in bone biological markers.

Clinically prescribed sunscreen (sun protection factor 15) does not decrease serum vitamin D concentration sufficiently either to induce changes in parathyroid function or in metabolic markers

Background The shortage of organs for transplantation is the most important factor limiting the number of transplants performed. Consequently, in recent years, criteria for considering a patient as a potential organ donor have been broadened. Methods From 1995 through 1996, we have retrieved organs from five donors who were brain dead because of bacterial meningitis. The causative microorganisms were Neisseria meningitidis in one patient, Streptococcus pneumoniae in three patients, and Escherichia coli in one patient. Fifteen organs were retrieved and transplanted into 16 recipients. All the donors and recipients received adequate antibiotic therapy. Results None of the recipients developed infectious complications caused by the meningeal pathogens. After a follow-up ranging from 4 to 30 months, 12 patients are alive with functioning grafts. The cause of death was noninfectious in the four patients who died. Conclusions Our study demonstrates that patients with brain death caused by bacterial meningitis due to meningococci, pneumococci, or E coli may be suitable organ donors. Transplantation of organs from such donors does not increase the risk of infection transmission to the recipient, provided that both donor and recipient had received adequate antibiotic therapy.

Successful transplantation of organs retrieved from donors with bacterial meningitis

Human-organ transplantation is the only effective therapy for many life-threatening diseases. However, despite an increase in transplant successes, the lack of a concomitant increase in donor organ availability has led to a growing disparity between supply and demand. Much research has thus focused on defining and implementing policies for increasing donor availability, identifying suitable organ recipients, and documenting transplant procedures. A novel organ-selection process uses a multiagent system called Carrel+ to let geographically dispersed transplant physicians deliberate over organ viability to increase the availability of organs for transplantation

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Increasing Human-Organ Transplant Availability: Argumentation-Based Agent Deliberation

Background. Among the main causes for the relatively small number of organ donors, the delay in the diagnosis of brain death plays a major role. Administration of drugs causing central nervous system (CNS) depression prevents diagnosis of brain death by clinical and electroencephalographic criteria until serum clearance of the drug has occurred. Confirming brain death by demonstrating persistent intracranial circulatory arrest might decrease the length of the diagnostic process. We have carried out a prospective study to investigate whether 99 m Tc-hexamethyl propylenamino oxime ( 99m Tc-HMPAO) brain scintigraphy and/or transcranial Doppler ultrasound can speed up the diagnosis of brain death in patients treated with CNS depressant drugs. Methods. All 138 consecutive patients with severe brain lesion that progressed to brain death in our center between January 1994 and December 1996 were controlled. Of them, 36 patients aged 1 to 65 years old (mean=25.6±18.3 years) who met clinical and EEG criteria for the diagnosis of brain death, except for the presence of significant serum levels of barbiturates (n=34), opiates (n=8), and benzodiazepines (n=3) were distributed in three groups according to the confirmatory test used; group 1: waiting for the metabolic clearance of CNS depressant drugs, or by demonstrating intracranial circulatory arrest with 99 m Tc-HMPAO (group 2) or transcranial Doppler (group 3). The delay in diagnosing brain death by the three methods was analyzed. Results. The mean interval between the presumptive and the definitive diagnosis of brain death was 34.4±32.2 hr in group 1, 17.7±18.3 hr in group 2, and 5.0±4.6 hr in group 3 (P=0.004). The between-groups analysis showed that 99 m Tc-HMPAO and transcranial Doppler decreased the delay in diagnosing brain death with respect to waiting for drug clearance by 49% (P=0.16) and 85% (P<0.001), respectively. Moreover, transcranial Doppler decreased this time by 72% with respect to 99 m Tc-HMPAO (P<0.01). Conclusions. Transcranial Doppler ultrasound and m Tc-HMPAO brain scintigraphy can significantly reduce the time taken to confirm brain death in patients with significant serum levels of CNS depressant drugs. In this setting, transcranial Doppler is superior to 99 m Tc-HMPAO in reducing the waiting time for a firm diagnosis of brain death.

A López-Navidad

Papers

Extended criteria for organ acceptance. Strategies for achieving organ safety and for increasing organ pool.

Clinically prescribed sunscreen (sun protection factor 15) does not decrease serum vitamin D concentration sufficiently either to induce changes in parathyroid function or in metabolic markers

Successful transplantation of organs retrieved from donors with bacterial meningitis

Increasing Human-Organ Transplant Availability: Argumentation-Based Agent Deliberation

Early diagnosis of brain death in patients treated with central nervous system depressant drugs