Information services and health promotion. What libraries can do.

Effective health promotion depends on a broad information base and with the help of new technology, librarians are responding to the challenge. Robert Gann introduces a new series of articles by health information specialists which describe some of the information services available in the field of health promotion, and suggest ways in which they may best be used.     

Incidence of coronary artery by-pass graft following percutaneous transluminal coronary angioplasty

Two hundred fifty eight patients had percutaneous transluminal coronary angioplasty. Of those, 48 cases underwent surgical revascularization for unsuccessful angioplasty. Sex was not a risk factor. Timely surgical revascularization reversed acute ischemia and/or myocardial infarction or limited the size of the infarction in 32 of the 48 patients or 67%. Revascularization procedures were performed in six out of forty-eight patients who had previous aortocoronary by-pass surgery and attempted PTCA, none had any complications. Death occurred in one out of forty-eight patients, or 2%. Femoral-femoral by-pass devices, in addition to intra-aortic balloon devices, should be available in the cardiac catheterization laboratory. Patients with multi-vessel disease are at greater risk of angioplasty and surgery. Sixteen out of 23 patients (70%) who had emergency revascularization procedures had multi-vessel disease. In one patient with borderline renal function, emergency surgery after PTCA with a large amount of renograffin dye injected caused renal failure and led to permanent dialysis.     

Exposure to formaldehyde and phenol during an anatomy dissecting course: sensitizing potency of formaldehyde in medical students

BACKGROUND: The sensitizing potency of formaldehyde and phenol during anatomy dissecting was investigated. The objective was to determine whether exposure induces specific IgE or IgG against formaldehyde-albumin or phenol-albumin. METHODS: In 27 medical students, specific IgE against formaldehyde-albumin by RAST plus ELISA and specific IgE against phenol-albumin by ELISA were assessed. In addition, specific IgG against formaldehyde-albumin was assessed in 23 students. Symptoms before and during dissecting were assessed, and indoor formaldehyde and phenol were measured. RESULTS: Mean indoor formaldehyde was 0.265 +/- 0.07 mg/m3, and mean indoor phenol was 4.65 +/- 2.96 mg/m3. Specific IgE/IgG against formaldehyde-albumin was not found at the beginning. Four students developed specific IgE against formaldehyde-albumin (RAST classes of > or =2.0), and all four also had specific IgE in the ELISA, but IgG against formaldehyde-albumin was not found. Specific IgE against phenol-albumin was not seen. Itch and paresthesia of the hands (P<0.00001), dizziness (P<0.008), burning eyes (P<0.01), headache, sneezing, epistaxis, gingival bleeding, oral or pharyngeal itch, and shortness of breath were experienced. CONCLUSIONS: Formaldehyde exposure during dissecting may induce specific IgE, but not IgG, against formaldehyde-albumin. Sensitization did not correlate with symptoms.     

Agonist-stimulated Ca2+ response in neutrophils from patients with primary alcoholism and alcoholized healthy subjects

The sensitivity of the inositol phosphate (IP)/Ca2+-second messenger generating system was assessed in neutrophils from healthy volunteers before and after ingestion of approximately 1%o ethanol for 2 h. In addition, isolated neutrophils from healthy subjects were incubated with ethanol in vitro. Furthermore, the sensitivity of the IP/Ca2+ system was evaluated in neutrophils from alcoholic patients in the state of active drinking, and after 2-3 weeks and 6 months of abstinence. EC50 values of the concentration-response curves obtained by agonist stimulation with formyl-methionyl-leucylphenylalanine (fMLP) of the intracellular Ca2+ accumulation were determined as an indicator of the sensitivity of the system. Ingestion of ethanol by healthy volunteers (both in the ex vivo and in vitro experiments) induced a rightward shift of the concentration-response curve (higher EC50 values) in neutrophils, indicating a reduced sensitivity to agonist stimulation evoked by ethanol. The sensitivity of the Ca2+ response in neutrophils from alcoholic patients decreased intraindividually after a period of 2-3 weeks of abstinence (higher EC50 values) and was at this time also significantly lower compared to a group of matched healthy controls In contrast, the maximal Ca2+ release induced by a saturating concentration of fMLP was increased after 2-3 weeks of abstinence, both intraindividually and in comparison to healthy controls. These alterations of the EC50 values and the maximal Ca2+ response were normalized after 6 months of abstinence. It is concluded that ethanol attenuates the sensitivity of the IP/Ca2+ system in neutrophils in healthy subjects. In neutrophils from alcoholic subjects complex alterations appear to persist up to several weeks, which are only normalized after a prolonged period of abstinence.     

Tooth pulp stimulation potentiates the adrenocorticotropin response to hemorrhage in cats

Stimulation of the maxillary tooth pulp nerve (TP), a predominantly nociceptive afferent fiber system, was assessed for its effect on peripheral plasma ACTH in chloralose-urethane anesthetized cats. These results were compared to those after a transient 10 ml/kg hemorrhage (H), a submaximal neurogenic stressor for ACTH release, and to H plus TP in combination. TP alone for 3 min had no significant effect on ACTH. However, TP during H greatly potentiated the increase in plasma ACTH concentration compared to that seen after H alone. The TP potentiation of the H-induced rise in ACTH was not accompanied by altered cardiovascular responsiveness nor by differences in plasma norepinephrine or glucose relative to that seen after H alone. The data indicate that nociceptive and baroreceptor afferents share a common neural substrate for selective facilitation of ACTH release, but do not interact to potentiate several other physiological responses, such as sympathetic efferent activity. Furthermore, under the conditions of these experiments, selective nociceptor activation in the anesthetized cat is not an adequate stimulus for the release of ACTH.     

Plasma beta-endorphin levels in silent myocardial ischemia induced by exercise

Although silent myocardial ischemia is a well recognized phenomenon, the reasons for the lack of symptoms in patients with coronary artery disease (CAD) is unclear. Because the endogenous opioid beta-endorphin has been related to pain modulation, plasma beta-endorphin levels were studied before, during and after exercise-induced ischemia in symptomatic and asymptomatic men. Because beta-endorphin responses have been closely linked to adrenocorticotropic hormone (ACTH) and cortisol responses, these hormones also were measured. Nine symptomatic and 12 asymptomatic patients with a high probability (at least 95%) of CAD and 8 apparently healthy men completed a Bruce protocol treadmill test. Blood samples were drawn before, during and 10 minutes after exercise. During exercise the measured hormones showed no significant increases from basal levels. However, plasma beta-endorphin, ACTH and cortisol levels were significantly elevated (p less than or equal to 0.01) 10 minutes after exercise in all 3 groups. There was no significant difference in plasma beta-endorphin levels during or after exercise between the symptomatic and asymptomatic patients with CAD. Thus, differences in circulating levels of beta-endorphin, ACTH and cortisol are not associated with the presence or absence of pain during exercise-induced myocardial ischemia.     

Efficacy of ursodeoxycholic acid in the treatment of primary sclerosing cholangitis in children

BACKGROUND: Ursodeoxycholic acid (UDCA) has been shown to be beneficial in reducing disease activity in adult patients with primary sclerosing cholangitis (PSC). However, there has been little published regarding PSC in children and no studies investigating the efficacy of UDCA as a treatment for PSC. METHODS: This retrospective study included 10 children who were found to have the diagnosis of PSC during the past 15 years at the Texas Children's Hospital and Herman Hospital, both in Houston, Texas. The male:female ratio was 8:2, the median age of onset was 12 years (range, 1-17 years), and eight patients had coexistent inflammatory bowel disease (IBD; six ulcerative colitis, one Crohn's disease, one unspecified). At the time of diagnosis, five patients were asymptomatic, all of whom had IBD with elevated liver enzymes and three of whom had hepatomegaly. Nine patients were treated with UDCA. The one patient who did not receive UDCA was lost to follow-up soon after diagnosis. The mean dose of UDCA was 17 mg/kg with the doses ranging from 9 to 37 mg/kg. RESULTS: There were no side effects from the medication recorded for any of the patients. These patients showed a significant reduction in alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyl transferase at 1, 3, 6, 15, and 20 months after treatment. CONCLUSIONS: This study demonstrates that children with PSC treated with UDCA have significant improvements in liver biochemical indices. However, the long-term effect of UDCA on clinical outcome is unknown.     

Purine nucleosides stimulate Na/K ATPase, and prolong survival in hemorrhagic shock

BACKGROUND: Hemorrhagic shock leads to the appearance of substances in plasma that depress Na/K ATPase activity leading to a rise in plasma potassium. Recently, we reported that adenosine can stimulate Na/K ATPase activity, lower the plasma potassium back to control and prolong survival in shocked rats. However, adenosine also caused bradycardia. We therefore searched for adenosine analogs that stimulate Na/K ATPase without the side effects of bradycardia. METHODS: Na/K ATPase activity was assessed using Rb uptake in erythrocytes. Pentobarbital anesthetized rats had their femoral artery and vein cannulated, bled to 35 mm Hg for 1 hour and resuscitated. RESULTS: We found that the purine nucleosides, inosine, guanosine, adenosine, deoxyadenosine and deoxyguanosine, stimulated Na/K ATPase in a dose-dependent manner and overcame partial inhibition by ouabain. However, the de-ribosylated bases, the nucleotides and the pyrimidines had little or no effect on Na/K ATPase activity. Purine nucleosides did not stimulate Na/K ATPase activity through adenosine receptors, as caffeine (1 mmol/L) or aminophylline (1 mmol/L) did not block stimulation. However, stimulation was blocked by inhibitors of the equilibrative nucleoside transporter (dipyridamole, 1 mmol/L, or S-(4-nitrobenzyl)-6-thioinosine, 10 micromol/L), suggesting that the mechanism of action is intracellular. Inosine, guanosine and adenosine (2.5 mmol/L) significantly increased survival of rats in hemorrhagic shock as compared with saline and cytidine controls, and lowered the shock-elevated plasma K. CONCLUSIONS: Purine nucleosides stimulate Na/K ATPase and prolong survival in hemorrhagic shock in rats, probably through an intracellular mechanism.