Food fortification with folic acid and twinning among California infants

This study sought to determine whether a change in twinning prevalence was associated with mandatory folic acid fortification. As of January 1998, it became mandatory in the United States that grain products be fortified with folic acid. The effectiveness of this fortification for neural tube defects has been explored, but other possible implications of fortification has not. We computed the prevalence of twinning among more than 2.5 million California births occurring from 1990 to 1999. The prevalence of twin births in California increased over the last decade with increases observed among most maternal race/ethnic, age, and parity groupings. Unadjusted prevalence measures did not reveal substantial increases in twinning prevalence among these groupings after the fortification period relative to the period immediately preceding it. Analyses that simultaneously adjusted for age, parity, race/ethnicity, sexes of twin pair (as a measure of zygosity), year of birth, and fortification period also did not reveal an association between fortification and twinning. Our results do not suggest a change in twinning prevalence associated with folic acid fortification of the US food supply among women delivering in California.     

Antiherpesvirus drugs: a promising spectrum of new drugs and drug targets

In the absence of effective vaccines to control herpesvirus infections, nucleosidic antiviral drugs have been the mainstay of clinical treatment since their development in the late 1970s. However, given the drawbacks of these drugs, including the increasing emergence of drug-resistant clinical isolates, new strategies for treating herpesvirus infections are warranted. A range of promising new drugs with novel molecular targets has been developed, but will they cure latent infections?     

Renoprotective effects of chronic candesartan treatment in uninephrectomized rat

The authors recently observed an age-dependent reduction in the diuretic and natriuretic responses to plasma volume expansion in uninephrectomized control and glucose-intolerant rats. To determine the involvement of angiotensin II AT receptors in this phenomenon, the authors tested the hypothesis that chronic candesartan treatment preserves renal excretory function in the uninephrectomized rat. Control and glucose-intolerant rats underwent right nephrectomy at 4 weeks of age. Two weeks later, the animals in each group were further subdivided and maintained on tap water containing either candesartan cilexetil (10 mg. kg(-1). day(-1) ) or vehicle. Renal excretory responses to acute extracellular fluid volume expansion (5% of body weight over 30 min) were determined in the 9-month-old conscious animal. Candesartan treatment markedly reduced the mean arterial pressure of controls and glucose-intolerant rats. Nonetheless, the baseline rates of fluid and electrolyte excretion, as well as the saline volume-induced diuretic, natriuretic, and kaliuretic responses, were greater in the candesartan-treated rats than in their vehicle-treated counterparts. The augmented baseline rates of fluid and sodium excretion in candesartan-treated rats were caused by a reduction in tubular reabsorption activity and an increase in glomerular filtration rate. However, the candesartan-mediated enhancement in saline volume-induced diuresis and natriuresis was caused by a reduction in tubular reabsorption activity. In addition to improving renal function, candesartan treatment reduced proteinuria in both groups. In conclusion, chronic blockade of the angiotensin II receptors exerts hypotensive and renoprotective effects in the aging uninephrectomized rat.     

Managing technology in a complex healthcare delivery system

Although clinical management is generally best handled regionally in a large system, e-health is the exception. E-health is managed centrally and not regionally because the patient access is not regional--it is virtual. Also, when patient demand, not business rationalization pressure, is the driver for change, it makes business sense to modify the management form from a regional to a centralized function.     

Pulmonary cystic hydatid disease in Ireland

Background Hydatid disease is rare in Ireland and its incidence and prevalence are unknown. Most cases are diagnosed by a combination of clinical findings, morphological features on imaging and by serological testing. Aims We describe an Irish case of pulmonary hydatid disease detected at bronchoscopy by bronchoalveolar lavage, and discuss the diagnosis and treatment of the disorder.     

Trends in knee magnetic resonance imaging

OBJECTIVE: To assess trends in knee magnetic resonance imaging (MRI) use and accompanying management changes to determine whether indications for this test have changed over time. DATA SOURCES: Large administrative database containing health care information for 587,010 people living in 1 state who were enrolled in the Medicare or Medicaid programs. They all had used health services during 3 consecutive years between 1991 to 1995. METHODS: We performed a retrospective cohort study examining the rates of lower extremity MRI in successive years and calculated the proportion of patients who were seen by a knee specialist or underwent knee surgery subsequent to the MRI. RESULTS: The annual rate of knee MRI was 1.4 per 1000 person-years in 1991 and increased by 140% to 3.4 per 1000 person-years by 1995 (P = 0.001). Approximately half of patients who underwent a knee MRI in 1991 had a diagnosis of internal derangement of the knee in the prior year; this figure dropped to 35% in 1995 (P < 0.001). The percentage of patients undergoing a knee MRI who had no record of any knee diagnosis in the prior year grew from 13% in 1991 to 33% in 1995 (P < 0.001). Over the 5 years of the study, the percentage of patients whose knee MRI was followed by specialist care or knee surgery decreased from 68% to 58%, a relative change of 15% (P < 0.005). CONCLUSION: Knee MRI use increased sharply during the study period, but the proportion of such patients who had a prior diagnosis of internal derangement or subsequently saw a knee specialist or underwent knee surgery decreased. This finding indicates that the criteria for knee MRI appear to have broadened substantially during this period.     

Nonvitamin, nonmineral supplement use over a 12-month period by adult members of a large health maintenance organization

OBJECTIVE: National survey data show an increase in the prevalence of nonvitamin, nonmineral (NVNM) supplement use among adults over the past 10 years. Concern over this trend is based in part on reports of potential drug-supplement interactions. The type and prevalence of supplement use by demographic and behavior characteristics were examined among members of a large group model health plan, including those with selected health conditions. DESIGN: Data on the use of herbal medicines and dietary supplements among survey respondents were analyzed. Questions employed a checklist for six specific NVNM supplements with optional write-ins. SUBJECTS/SETTING: A stratified random sample of 15,985 adult members of a large group model health maintenance organization in northern California, who were respondents to a 1999 general health survey. STATISTICAL ANALYSES PERFORMED: Analyses were conducted with poststratification weighted data to reflect the actual age, gender, and geographic distribution of the adult membership from which the sample was drawn. RESULTS: An estimated 32.7% of adult health plan members used at least one NVNM supplement. The most frequently used herbs were Echinacea (14.7%) and Gingko biloba (10.9%). Use of all NVNM supplements was highest among females, 45 to 64 years of age, whites, college graduates, and among those with selected health conditions. APPLICATIONS: Dietetics professionals need to uniformly screen clients for dietary supplement use and provide accurate information and appropriate referrals to users.     

Cellular characterization of an in-vitro cell culture model of seal-induced cardiac ischaemia

The lack of a well-characterized in-vitro cell culture model of load-induced cardiac ischaemia has hampered investigations into the mechanism of ischemic injury. We therefore developed a new in-vitro model of cardiac ischaemia that mimics distinct features of ischaemic injury. Neonatal rat heart cells were cultured in a sealed flask for 24-72 h. In this environment, the cells were exposed to stresses of hypoxia, acidosis and stagnant incubation medium. The pO2 and pH of the medium gradually decreased during the ischaemic insult and ultimately fell to a level of 14 mmHg and pH 6.8, respectively. The model triggered severe cell injury, including morphological degeneration, CPK release, beating impairment and ATP depletion. Apoptosis occurred in some cardiomyocytes as early as 24 h after onset of seal-induced ischaemia. This was evidenced by positive nuclear staining using Hoechst 33258 and by the induction of caspase-3 mRNA. By 72 h, internucleosomal DNA fragmentation was observed in 45% of the myocytes; however, a non-myocyte preparation subjected to the same ischaemic insult exhibited no evidence of DNA fragmentation. These results demonstrate that neonatal cardiomyocytes subjected to the new simulated ischaemia model exhibit several similarities to cardiac ischaemia, including the simultaneous appearance of necrosis, breakdown of cellular ATP, beating cessation and apoptosis. The new model should prove useful in unravelling the molecular alterations underlying ischaemic injury and myocardial apoptosis.     

Taurine modulates arginine vasopressin-mediated regulation of renal function

Taurine has been implicated in the regulation of arginine vasopressin (AVP) secretion, and we have previously shown altered renal excretory function in the taurine-depleted rat. To further elucidate the role of taurine in AVP-mediated renal responses, the effects of an antagonist for renal AVP receptors were examined in four groups of conscious rats: control, taurine-supplemented, taurine-depleted, and taurine-repleted. Control and taurine-supplemented rats displayed similar and significant AVP receptor antagonist-induced elevations in fluid excretion, sodium excretion, and free water clearance but a marked reduction in urine osmolality. These effects are consistent with inhibition of endogenous AVP activity. By contrast, in the taurine-depleted rats, the magnitude and the time course of drug-induced renal excretory responses lagged behind those of the control and taurine-supplemented groups. Further, baseline urine osmolality was significantly higher in the taurine-depleted compared with the control or taurine-supplemented groups. However, after administration of the antagonist, taurine-depleted rats manifested a delayed but more marked reduction in urine osmolality, thereby eliminating the baseline differential that existed between the taurine-depleted rats and control or taurine-supplemented groups. Consistent with these observations, plasma AVP was significantly increased in the taurine-depleted compared with the control rats. Interestingly, taurine repletion shifted all responses closer to the control group. Analysis of the data suggests that the effect of the antagonist on renal excretory function is related primarily to altered tubular reabsorption activity. These observations suggest that taurine modulates renal function, and, thereby, body fluid homeostasis, through an AVP-dependent mechanism.