Prevalence of Ethanol Use Among Pregnant Women in Southwestern Uganda

Introduction The prevalence of ethanol use in many Sub-Saharan African countries is high, but little research exists on use during pregnancy. The objective of this study was to assess the prevalence and predictors of ethanol use among pregnant women in Southwestern Uganda. Methods This descriptive, cross-sectional study was conducted in the maternity ward at Mbarara Regional Referral Hospital (MRRH). All pregnant women giving birth at MRRH between September 23, 2013 and November 23, 2013 were eligible for enrollment. The primary outcome was the proportion of women with ethanol use during pregnancy as determined by self-report. Secondary outcomes included the proportion with positive fatty acid ethyl ester (FAEE) results (indicating ethanol use) and positive TWEAK questionnaire results (indicating possible problem drinking). Predictors of ethanol use were assessed and stratified by patterns of ethanol intake. Results Overall, 505 mother-child dyads enrolled in the study. The proportion of women who reported any ethanol use during pregnancy was 16 % (n = 81, 95 % CI 13-19 %) and the prevalence of heavy drinking 6.3 % (n = 32, 95 % CI 3.8-7.9 %). The strongest predictor of use during pregnancy was pre-pregnancy use, with maternal education as a protective factor. Few neonates (n = 11, 2 %) tested positive for FAEE > 2.00 nmol/g in meconium. The TWEAK questionnaire captured 75 % of women who reported moderate/heavy drinking and aligned more with self-reported ethanol use than meconium results. Conclusions The substantial prevalence and clear predictors of ethanol use suggest that legislative action and educational interventions to increase awareness of potential harms could assist in efforts to decrease use during pregnancy in Southwestern Uganda.

Escape and survival of Corophium volutator and Ilyanassa obsoleta exposed to freshwater and chlorothalonil

The behavioural response and survival of marine mud snails and mud shrimp exposed to freshwater and the fungicide chlorothalonil (tetrachloroisophthalonitrile) was investigated. Amphipods were less tolerant of lower salinity than snails, with 50 and 76% survival associated with 5 and 0% seawater in freshwater, respectively. However, 50% of snails displayed a defence mechanism by retracting within their shell when exposed to 70% freshwater. Both species displayed an avoidance to chlorothalonil spiked at >100 ng/g and/or >100 ng/mL in sediments and seawater, respectively. The avoidance response of amphipods was observed along with a reduced swimming ability and increased lipid content. Snails displayed a higher susceptibility to physical stress, with an increased number unable to twist from being on their shell to their foot, and with longer righting time. Behaviour was affected at chlorothalonil concentrations of 0.001-0.01 ng/g and/or ng/mL, with a variability that could be due to degradation by the microbial community. Ascertaining the latter observations requires state-of-the-art chemical analyses.

The aging population and Natural Occurring Retirement Communities (NORCs); local government, healthy aging, and healthy-NORCs

BACKGROUND

The term Naturally Occurring Retirement Communities (NORCs) has been used since the 1980s. NORCs are defined as communities where people remain or move to when they retire. NORCs develop 'naturally', meaning that seniors tend to remain or move there when they retire, although the residences and physical environment were not constructed for a senior population. The term, Healthy-NORC, has been introduced and is associated with healthy aging.

OBJECTIVES/METHODS

We describe how demographic trends will facilitate a dramatic growth in NORCs. Acknowledging the 'Determinants of Health' model, we suggest that some determinants impact people differently at different ages. We also suggest that more attention be focused on the impact of physical/social environments on health, and that some determinants of health are particularly relevant for seniors. We argue that NORCs exist on a spectrum, from NORC to H-NORC, and that health benefits for seniors increase as NORCs adopt additional characteristics associated with improved senior health. We also illustrate H-NORC research methods and policy options for local governments.

RESULTS/CONCLUSION

Compared to the provision of additional medical and social services, H-NORCs represent a low-cost approach to facilitating healthy aging. Municipal governments can promote healthy aging and should pursue policies that will stimulate H-NORC development.

Bridging the research gap: aboriginal and academic collaboration in FASD prevention. The Healthy Communities, Mothers and Children Project

OBJECTIVES

The objective was to assist with the prevention of Fetal Alcohol Spectrum Disorder through a participatory research approach involving local women and health care workers. Our interest was in understanding how well communities could develop culturally appropriate methods of helping women to reduce their alcohol consumption during pregnancy.

STUDY DESIGN

Four geographically distant Aboriginal communities were presented with a task of adapting a standard Brief Alcohol Intervention, and in particular to develop a culturally appropriate means of using the Intervention with women in the community.

METHODS

Academic and Aboriginal community researchers worked together in partnership, using a participatory action research approach to address alcohol use during pregnancy.

RESULTS

The outcome of the project was the design of four differing models of culturally appropriate community interventions designed to support vulnerable women in their childbearing years. The intervention models developed by the four communities have five core characteristics: (1) identification of women at risk; (2) assessment of the woman's drinking/ drug use; (3) provision of information to the women; (4) delivery method facilitates the decision to adopt healthier behaviors; and (5) means to monitor changes.

CONCLUSION

This project was considered successful in many respects: (1) each community developed a culturally-relevant prevention tool; (2) community involvement in the design lead to better understanding of its usefulness; (3) considerable knowledge exchange between academic and community partners took place; and (4) most importantly, it was found that community members can be active members in developing and implementing solutions to important public health issues.

The Optimal Drug Therapy National Symposium 2001: a call for action

There is widespread concern internationally and within Canada about the rapid escalation in pharmaceutical costs. Although there is reason to believe that the quality of prescribing has improved in recent years, with heightened emphasis on evidence-based therapeutic decision-making, there is enormous pressure to prescribe in almost every clinical situation. Busy clinicians need improved tools to aid therapeutic decision-making. Access to timely information about drug efficacy and safety is essential. Most importantly, there is a need for a new partnership model that may blend the interests of patients, professionals, payors and manufacturers to better define disease state management approaches that will lead to an optimal return on the investment in pharmaceutical care. The new model will depend on high standards of research to show what does and does not work to secure the most effective pharmacotherapy. It will also require renewed efforts in education for patients and caregivers, and progress on that front will, in turn, rely on the most effective use of expanded capacity in information technology. One early impact will be seen in the reduction of medication errors. The framework for therapeutic decision-making must evolve in keeping with the revolution in human biology. With improved understanding of human genomics and proteomics, prescribers are better able to consider highly individualized and targeted drug therapies while actively concentrating on risk minimization. The Optimal Drug Therapy National Symposium 2001 has created a consensus among stakeholders and pointed the way to improvements in drug therapy that may be achieved through enhanced research, educa- tion, public involvement and professional support. Unequivocal commitment to the laudable goal of optimal drug therapy is now required from all sides.

Genetic deletions of glutathione-S-transferase as a risk factor in squamous cell carcinoma of the larynx: a preliminary report

PURPOSE

To test whether genetic deletions of glutathione-S-transferase (GST) are associated with squamous cell carcinoma (SCC) of the larynx. GST are a group of detoxifying enzymes that may help reduce the risk of developing cancer in response to environmental carcinogens. Polycyclic aromatic hydrocarbons, found in high concentration in cigarette smoke, are known carcinogens especially for SCC of the larynx. Individuals with absolute or relative deficiency of the GST enzyme system may therefore be at a higher risk of developing laryngeal carcinoma.

MATERIALS AND METHODS

Genotyping for GST-M1 and GST-T1 was performed using polymerase chain reaction (PCR) assay on fresh frozen tissue specimens of 20 patients with SCC of the larynx and on 20 control subjects with a similar smoking history. Because this assay results in the absence of a PCR product in individuals expressing the GST-M1/GST-T1 null genotype, oligonucleotide primers that amplify a portion of the albumin gene were included in a multiplex PCR as a positive control for DNA quality and PCR conditions. The chi-square test was used for statistical analysis.

RESULTS

GST-M1 gene was deleted in 80% of patients with laryngeal SCC and in 50% of control subjects (P <.05). No statistically significant difference was observed in the incidence of GST-T1 gene deletion in patients with SCC of the larynx and control subjects.

CONCLUSION

GST-M1 gene deletion was significantly associated with SCC of the larynx and may produce a risk for this particular disease.

Endoscopic drainage of the pancreatic pseudocyst

BACKGROUND

Pancreatic pseudocyst is a common complication of chronic pancreatitis occurring in 20% to 40% of cases. Pseudocysts can be treated by endoscopic cystenterostomy or transpapillary drainage, percutaneously with computed tomography guidance or operatively.

METHODS

A total of 36 endoscopic pancreatic pseudocyst drainage procedures were performed in 29 patients with 34 pseudocysts. Eighty percent presented with chronic pain, 25% had recurrent pancreatitis, and approximately one half of the patients had either gastric outlet obstruction or a palpable abdominal mass.

RESULTS

Thirty-six endoscopic drainage procedures were performed, 27 cystenterostomies and 9 transpapillary drainages. Endoscopic treatment achieved complete resolution of the pseudocyst in 24 of 29 patients (83%), and the other 5 (17%) eventually required surgery. Two patients required distal pancreatectomy because of their pancreatic pathology, 2 cystgastrostomies for persistence of the pseudocyst, and 1 external drainage of an infected pancreatic cyst. The mean follow-up after the initial drainage was 16 months. There were no deaths attributed to the procedures and no complication that required surgery. Only 1 nonadherent pseudocyst (cystadenoma) required immediate operation after attempted endoscopic drainage.

CONCLUSIONS

The conclude that endoscopic drainage of pancreatic pseudocysts can be both safe and effective, and definitive treatment. It should be considered as an alternative option before standard surgical drainage in selected patients.

In vivo human metabolism of [2-14C]2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)

To better understand the interactions of the pathways of activation and detoxification on the metabolism of the putative carcinogen, PhIP, we administered a dose of 70-84 microg [2-14C] PhIP (17.5 [microCi 14C) 48-72 h before scheduled colon surgery. Blood and urine collected for the next 48-72 h was evaluated by linear accelerator mass spectroscopy (AMS) and scintillation counting LC-MS to identify specific PhIP metabolites. The thermostable phenol sulfotransferase (SULT1A1) phenotype was correlated with the 4'-PhIP-SO4 levels in the urine at 0-4 h (R = 0.86, P = 0.059). The CYP1A2 activity had a negative correlation with PhIP serum levels at 1 h (R = 0.94, P = 0.06) and a positive correlation with urine N-OH-PhIP levels at 0-4 h (R = 0.85, P = 0.15). This low level radioisotope method of determining the influence of phenotype on metabolism will significantly improve our understanding of the interrelationships of these pathways and provide a critical foundation for the development of individual risk assessment.

The identification of [2-(14)C]2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine metabolites in humans

[2-(14)C]2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine ([14C]PhIP), a putative human carcinogenic heterocyclic amine found in well-done cooked meat, was administered orally to three colon cancer patients undergoing a partial colonectomy. Forty-eight to seventy-two hours prior to surgery, subjects received a 70-84 microg dose of 14C. Urine and blood were analyzed by HPLC for PhIP and PhIP metabolites. Metabolites were identified based on HPLC co-elution with authentic PhIP metabolite standards, mass spectral analysis and susceptibility to enzymatic cleavage. In two subjects, approximately 90% of the administered [14C]PhIP dose was eliminated in the urine, whereas in the other, only 50% of the dose was found in the urine. One subject excreted three times more radioactivity in the first 4 h than did the others. Twelve radioactive peaks associated with PhIP were detected in the urine samples. The relative amount of each metabolite varied by subject, and the amounts of each metabolite within subjects changed over time. In all three subjects the most abundant urinary metabolite was identified as 2-hydroxyamino-1-methyl-6-phenylimidazo[4,5-b]pyridine-N2-glucuron ide (N-hydroxy-PhIP-N2-glucuronide), accounting for 47-60% of the recovered counts in 24 h. PhIP accounted for <1% of the excreted radiolabel in all three patients. Other metabolites detected in the urine at significant amounts were 4-(2-amino-1-methylimidazo[4,5-b]pyrid-6-yl)phenyl sulfate, N-hydroxy-PhIP-N3-glucuronide and PhIP-N2-glucuronide. In the plasma, N-hydroxy-PhIP-N2-glucuronide accounted for 60, 18 and 20% of the recovered plasma radioactivity at 1 h post PhIP dose in subjects 1, 2 and 3 respectively. Plasma PhIP was 56-17% of the recovered dose at 1 h post exposure. The relatively high concentration of N-hydroxy-PhIP-N2-glucuronide and the fact that it is an indicator of bioactivation make this metabolite a potential biomarker for PhIP exposure and activation. Determining the relative differences in PhIP metabolites among individuals will indicate metabolic differences that may predict individual susceptibility to carcinogenic risk from this suspected dietary carcinogen.

Polymorphisms of CYP1A1 and GSTM1 influence the in vivo function of CYP1A2

Differences in human cancer susceptibility have been attributed to polymorphisms of carcinogen metabolizing enzymes. Our efforts have focused on the systems responsible for metabolism of aromatic and heterocyclic amines found in cigarette smoke and in cooked foods. Cytochrome P4501A2 (CYP1A2), which catalyzes aromatic and heterocyclic amine N-oxidation, has been implicated as a risk factor in both urinary bladder and colorectal cancer. In the present study we used the results of caffeine phenotyping experiments to measure the effects of cigarette smoke and compounds present in meat cooked at high temperature on CYP1A2 activity. Subjects in the smoking cessation study had mean CYP1A2 activity of 17.8 (expressed as the urinary molar ratio of [17X + 17U]/137X) while smoking: however, this activity decreased to 10.9 three weeks after cessation of smoking. Subjects in the cooked meat feeding study had mean CYP1A2 activity of 9.01 after 1 week of consuming meat cooked at low temperature, but this value increased to 12.7 after 1 week of consuming meat cooked at high temperature. Because no association has been identified between differences in CYP1A2 activity and variations in the CYP1A2 structural gene, we sought to determine whether the activities of other carcinogen metabolizing enzymes are involved in the regulation of CYP1A2 activity. CYP1A2 activity was higher in individuals who express the GSTM1 null allele compared to those expressing the GSTM1*A,B allele, 10.2 vs. 8.5 for unexposed conditions and 15.0 vs. 12.3 for exposed conditions. CYP1A1 genotyping demonstrated that individuals possessing the Ile/Ile CYP1A1 genotype had greater mean CYP1A2 activity than those who had the heterozygous Ile/Val allelic variant of the CYP1A1 gene. However, upon exposure to cigarette smoke or high-temperature cooked meat, individuals possessing the heterozygous form of the CYP1A1 gene had significantly increased CYP1A2 activity (18.1) compared to those with the more common Ile/Ile CYP1A1 genotype (13.3). These results indicate that CYP1A2, CYP1A1, and GSTM1 gene-gene interactions could be important confounders in the interpretation of molecular epidemiology studies.

Interleukin-6 prevents dexamethasone-induced myeloma cell death

The effects of dexamethasone on the growth of four human multiple myeloma cell lines were studied. In addition, the effects on the expression of interleukin-6 (IL-6) and IL-6 receptor (IL-6R) genes were investigated by the use of reverse-transcriptase polymerase chain reaction. Dexamethasone (Dex) concentrations of 10(-7) to 10(-6) mol/L inhibited IL-6 gene expression in three of four cell lines studied, whereas the higher concentration of the hormone inhibited also IL-6R gene expression. Dex effects were modulated through the glucocorticoid receptor (GR). Dex treatment resulted in killing of sensitive cells associated with DNA fragmentation, which could be reversed by concomitant treatment with IL-6. The reversal of Dex-mediated effects by IL-6 did not result from an inhibition of GR function as measured by receptor nuclear translocation or Dex-regulated reporter gene function. These results indicate that blockage of the IL-6 signaling pathway is essential for effective myeloma cell kill by Dex.

Effects of glucocorticoids on expression of the fos protooncogene in AtT-20 cells

Glucocorticoid regulation of expression of the protooncogene fos has been examined in AtT-20 cells at both the RNA and protein levels. When cells were incubated continuously in the presence of dexamethasone, an early (30 min) rise in the expression of fos mRNA was observed, which declined by 1 h, but rose again after 2 h of hormone treatment. Six hours after hormone treatment, fos mRNA levels had returned to control levels in spite of the continued presence of dexamethasone. Serum treatment resulted in a sustained increase in fos mRNA levels; however, the glucocorticoid and serum effects were additive. Dexamethasone and/or serum both increased the steady state levels of fos protein. Glucocorticoid treatment of AtT-20 cells results in complex changes in fos expression, but does not affect their viability or growth rate; these results suggest that fos may play a role in mediation or modulation of glucocorticoid effects other than growth.

Interpretation of elevated postmortem serum concentrations of digoxin in infants and children

The relationship between excessive postmortem digoxin concentrations (greater than 6.4 nmol/L) and administered dose, and antemortem levels and time of sampling after death were determined in 27 digitalized children who died in our hospital between March 24, 1981 and September 1, 1983. In all 27 cases, postmortem concentrations were higher than antemortem levels (9.5 +/- 2.5 nmol/L and 3.12 +/- 1.72 nmol/L, respectively). In none of these patients was there clinical or electrocardiographic evidence of digitalis toxicity. There was a significant correlation between antemortem and postmortem determinations, and between time of sampling after death and postmortem concentration. Positive correlation existed between antemortem or postmortem concentrations and dose per kilogram. The degree of elevation in digoxin levels was uniform in most cases, and the likelihood of elevation falling in the range 3.5 to 7.0 nmol/L was 66%. If the estimated concentration of digoxin at the time of death was taken as baseline, in 75% of cases the subsequent elevation was between 5.3 and 8.3 nmol/L (mean, 6.5 +/- 1.1 nmol/L). Digoxin concentrations measured in newborn infants not receiving digoxin were significantly higher after death (1.5 +/- 0.3 nmol/L) than in age-matched living infants not receiving digoxin (0.5 +/- 0.3 nmol/L). These data indicate that the size of antemortem dose, the time of sampling after death, and existence of endogenous digoxinlike factors affect postmortem readings of digoxin levels. Consequently, excessive postmortem determinations cannot be directly interpreted as proof of toxic antemortem levels.

Effects of quinidine on the renal tubular and biliary transport of digoxin: in vivo and in vitro studies in the dog

Quinidine is known to inhibit the renal clearance of digoxin without affecting glomerular filtration rate. The renal interaction between these drugs was investigated by a combination of in vivo and in vitro methods. The uptake of digoxin by brush border membrane vesicles was not affected by quinidine. Similarly, digoxin did not inhibit the uptake of the cation N-methylnicotinamide by these vesicles and did not alter the binding kinetics of digoxin to the Na+, K+-adenosine triphosphatase by the antiluminal membrane vesicles. By using the in vivo multiple indicator dilution technique transtubular transport of digoxin was documented; renal-artery infusion of quinidine did not affect the recovery of digoxin in the renal vein or urine. Clearance studies documented that the decrease in the renal clearance of digoxin is paralleled by a significant fall in renal blood flow evidenced by a decrease in p-aminohippuric acid clearance. It is concluded that quinidine inhibits the renal excretion of digoxin not by competition at the tubular cell membrane level, but rather by decreasing renal blood flow. A parallel decrease in biliary clearance of digoxin is documented and may suggest a similar mechanism.

Is pinworm a vanishing infection? Laboratory surveillance in a New York City medical center from 1971 to 1986

Records of our parasitology laboratory were reviewed to determine trends in the frequency of specimens submitted for diagnosis of pinworm infection, the proportion of such specimens that were positive, and the proportion of such positive results for the pediatric age group from 1971 to 1986 in a major New York City medical center. These data demonstrate a markedly declining trend in the absolute number of sticky tape tests sent for pinworm diagnosis, from 248 in 1971 to 38 in 1986, an average of 8% decline per year. The number of specimens identifying Enterobius vermicularis among those submitted has similarly declined, from 57 in 1971 to none being positive in 1986, an average of 16% decline per year. The dramatic decline in pinworm identification and the fall in the number of specimens sent by practitioners at this medical center, and reported elsewhere in the United States by other investigators, may reflect a genuine decline in oxyuriasis occurring in the patient populations served.

The effects of maternal age and parity on birthweight: a population-based study in New York City

New York City birth certificates for singletons born from September 1-December 31, 1981 (N = 36,056) were analyzed using multivariate regression techniques. The effects of maternal age and parity on birthweight were assessed. There was a significant progression of birthweight with advancing age. Birthweight similarly increased from parity 1 to parity 3, but dropped markedly in the higher parity groups. On stratification by gestational age, we found that age and parity influence birthweight by affecting fetal growth rather than the length of pregnancy.

Into Africa: the telemedicine links between Canada, Kenya and Uganda

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Cellular mechanisms of digoxin transport and toxic interactions in the kidney

Renal tubular secretion of digoxin appears to be one of the main ports of elimination of the glycoside from the body. Because of its narrow therapeutic window and severe toxicity, the mechanisms of tubular handling of digoxin are important. Moreover, several drugs which are commonly administered with digoxin, including quinidine, spironolactone, verapamil and amiodarone have been shown to decrease renal clearance of digoxin without affecting GFR. We studied the handling of digoxin using in vitro and in vivo approaches. The handling of the glycoside by the brush border suggests passive reabsorption which is not enhanced by commonly coadministered drugs. Digoxin binding to the antiluminal (basal) membrane suggests that the secretion of the glycoside may not involve the pharmacologic receptor, the Na+, K+, ATPase. Using the multiple indicator dilution technique, we could directly show the two steps of secretion of digoxin: Its sequestration from the postglomerular circulation, and its appearance in the urine after transtubular transport. Digoxin transport is not inhibited by a cationic or anionic molecule (PAH and tolazoline). It is possible that digoxin is secreted by a yet unidentified transport mechanism.

Parasitic infections in a New York City hospital: trends from 1971 to 1984

We report the frequency of parasitic infections 1971-84 in a major New York City Medical Center whose catchment area includes many immigrants from Dominican Republic. Infection with 7,803 parasites was documented in 41,958 laboratory specimens. Trends were toward fewer total specimens being sent and fewer still being positive, although a rise in G. lamblia, E. histolytica, and Cryptosporidium is apparent in recent years. Parasitology laboratories should provide similar data to alert clinicians to the parasites prevalent locally.

Taeniasis unresponsive to a single dose of niclosamide: case report of persistent infection with Taenia saginata and a review of therapy

A patient infected in Ethiopia with the beef tapeworm Taenia saginata was unsuccessfully treated with 2 g of niclosamide on four separate occasions over four months. clinical and parasitologic cures were effected by a regimen of 2 g of niclosamide given on three consecutive days. Niclosamide is the drug of choice for treatment of T. saginata and Taenia solium (pork tapeworm) infection; cure rates are approximately 90%. It is not absorbable and thus is nontoxic. Alternative treatments of taeniasis vary in the degree of safety; tin compounds and Aspidium extracts often are toxic. Paromomycin sulfate, which is also nonabsorbable, is effective, although adverse gastrointestinal effects are common with multiple-dose regimens. A relatively safe therapy is with mebendazole, a broad-spectrum anthelmintic agent, although efficacy has varied in different trials. A number of benzimidazoles, as well as nitazoxamide, have been effective against tapeworms. Praziquantel is the best alternative to niclosamide in terms of cost, efficacy, availability, and safety.

Significance of the endogenous digoxin-like substance in infants and mothers

Digoxin serum concentrations were measured by a routine radioimmunoassay in 30 neonates not receiving digoxin; nonetheless, digoxin levels were between 0.17 nM and 1.64nM (means = 0.64nM +/- 0.27 nM). There was a negative correlation between gestational age and concentration of an endogenous digoxin-like substance (EDLS). Neonates less than or equal to 32 wk gestational age had higher levels of EDLS than neonates greater than 32 wk old. EDLS concentrations were compared in 22 mothers and their 24 offspring and were higher in all newborn infants (0.34nM +/- 0.09nM and 0.15nM +/- 0.08nM). EDLS was shown to inhibit Na+-K+-adenosinetriphosphatase activity by measurement of 86Rb uptake in erythrocytes exposed to sera samples from 30 infants in the study. EDLS levels greater than 0.6 ng/ml were associated with lesser 86Rb uptake. Simulation kinetics suggest that the presence of 0.6nM EDLS would lengthen the digoxin t1/2 by 64%, reduce the volume of distribution by 23%, and lower clearance by 53% if the peak "true" digoxin level were 2 ng/ml. EDLS concentrations of 1.5 ng/ml would increase the t1/2 by 207% while reducing the volume of distribution by 43% and clearance by 81%. These considerations cast serious doubts on the validity of currently accepted digoxin kinetics and dosing in preterm infants.

Aminoglycoside-related nephrotoxicity in the premature newborn

The nephrotoxicity of gentamicin and amikacin was compared during presumed sepsis in 107 premature neonates. To examine the possibility that nephrotoxicity was directly associated with the clinical conditions of "sepsis," a control group of 26 chloramphenicol-treated newborns was also studied. Two markers of proximal renal tubular injury, N-acetyl-beta-glucosaminidase (NAG) and beta 2-microglobulin, were measured in 6-hr aliquots of urine. Because urine creatinine excretion increased with postconception age, markers were expressed in terms of excretion rate rather than per milligram of creatinine. The NAG excretion rate was significantly higher in gentamicin-treated patients (138 +/- 10 U/min, mean +/- SE) than in amikacin-treated patients (85 +/- 7 U/min) but did not differ between patients treated with amikacin and those treated with chloramphenicol (81 +/- 11 U/min). Excretion of beta 2-microglobulin did not differ among the three patient groups. We conclude that amikacin may be less nephrotoxic than gentamicin in the premature newborn.

Assessment of immediate post-anaesthetic recovery in young children following intravenous morphine infusions, halothane, and isoflurane

Within 15 minutes of terminating general anaesthesia, progressive recovery of consciousness, spontaneous ventilation and cough, and limb movements were assessed in 60 young children (age range 0-5 years, mean +/- SEM; 2.83 +/- 0.34; weight 13.86 +/- 0.41 kg). All patients were ASA physical status class I-III, received a standard intravenous induction (atropine 0.02 mg X kg-1, thiopental sodium 5 mg X kg-1, diazepam 0.2 mg X kg-1), were intubated with an orotracheal tube following the administration of metocurine, 0.4 mg X kg-1, and were maintained under general anaesthesia with nitrous oxide and oxygen in a 70:30 mixture administered by a T-piece circuit. They were ventilated mechanically to maintain normal blood-oxygen tension and normocarbia. The patients were assessed in three equal groups according to the anaesthetic supplement they received. Group I received intravenous infusions of morphine sulfate (loading dose 60 micrograms X kg-1 administered over 5 minutes followed by a continuous intravenous infusion of 2 micrograms X kg-1 X min-1. Patients in Groups II and III had 0.5 per cent halothane and 1.0 per cent isoflurane respectively added to the nitrous oxide/oxygen fresh gas mixture rather than morphine sulphate infusions. By the end of the study period, there was no significant difference in the degree of recovery between the morphine and the isoflurane groups but the patients in the halothane group had recovered to a lesser degree. Generally, the patients in the morphine group were awake but not crying, while those in the other two groups were less sedated.

Theophylline disposition in cystic fibrosis

The disposition of intravenously and orally administered theophylline was compared in 10 patients with cystic fibrosis (CF) and 10 healthy volunteers. The mean total body clearance of the patients with CF was twice that of the control subjects (p less than 0.001). The volume of distribution of theophylline was also greater in the patients with CF (p less than 0.05). These observations indicate that if theophylline is used in patients with CF, doses larger than those commonly given to asthmatics may be required to maintain therapeutic serum concentrations.

Chloramphenicol pharmacokinetics in the newborn

We studied pharmacokinetics of chloramphenicol in 9 neonates having a mean gestational age of 31.2 +/- 1.9 weeks (mean +/- SEM). The studied dose was the final dose of treatment in 8 of these and the first dose in 2 of these. 1 neonate was studied twice. Concentrations of chloramphenicol and its 3-monosuccinate and 1-monosuccinate esters were measured in serum by high performance liquid chromatography. Apparent total body clearance of chloramphenicol correlated with postnatal age (r = 0.81, p less than 0.01). Mean apparent clearance was 1.1 ml X min-1 X kg-1. Serum concentrations of succinate esters were below assay sensitivity after 6 h postdose. Factors leading to excessive chloramphenicol concentrations (greater than 25.0 mg/l) were evaluated in another 44 newborns. Instability of the patient's clinical condition was an important cause of excessive serum concentrations during ongoing therapy.

Initiation of chloramphenicol therapy in the newborn infant

To evaluate the ability of a loading dose of chloramphenicol succinate to rapidly, achieve adequate serum concentrations of chloramphenicol, we compared two intravenously administered dosages of chloramphenicol succinate given to initiate treatment. Thirteen premature neonates received an initial dose of 12.5 mg/kg; 26 received a loading dose of 20 mg/kg. Capillary blood samples were obtained at two, four, and 12 hours after the first dose. After the dose of 12.5 mg/kg, 45% of the neonates did not achieve serum concentrations greater than 10 mg/L. After the loading dose of 20 mg/kg, all neonates achieved concentrations greater than 10 mg/L. The peak chloramphenicol concentrations after the 12.5 mg/kg dose was 8.8 +/- 11.2 mg/L (+/- SEM) and after the 20 mg/kg loading dose, 15.9 +/- 0.7 mg/L. The disposition of chloramphenicol was age dependent. Chloramphenicol concentration peaked at four hours in neonates less than or equal to 2 days postnatal age and at two hours in neonates 3 to 55 days postnatal age. Chloramphenicol succinate concentrations were greater in younger than in older neonates at both two and four hours after the dose. We conclude that a loading dose is appropriate when using chloramphenicol succinate in neonates.

Performance on a reciprocal tapping task with variations in intertapping interval

Fitts' law was investigated in a study of the effect of the index of difficulty (ID) and intertapping interval upon reaction time (RT) and movement time (MT) for a reciprocal tapping task. ID showed its well-established relationship with MT as described by Fitts' law: MT = aID + b. Improvement in the linearity of this relationship was, however, demonstrated by expressing MT in logarithmic units. While ID had an unsubstantial (though significant) effect on RT, increases in intertapping interval from zero to any level of discrete tapping led to significant increases in RT of about 135 msec. The results are interpreted as lending support to Fitts' thesis that RT and MT reflect independent phases of information processing.

Ethanol and spinal presynaptic inhibition in man

Ethanol, 0.65 gm per kilogram of body weight, was administered orally to 6 normal subjects. The mean blood ethanol levels ranged from 0.74 to 0.99 gm per liter over a subsequent 40-minute testing period. The proportion of the soleus motoneuron pool activated by the Achilles tendon reflex was reduced. Vibratory inhibition of the monosynaptic reflex was used as an estimate of spinal presynaptic inhibition. It was unaffected by ethanol.

Diazepam effect on reflex activity in patients with complete spinal lesions and in those with other causes of spasticity

The effects of diazepam on reflex pathways in patients having complete spinal lesions and in patients having incomplete lesions of the spinal cord or multiple sclerosis are compared to determine whether diazepam has an action at spinal level. The drug produced no significant alteration in the excitability of the monosynaptic arc in the patients with complete spinal lesions. In contrast, in the group with incomplete spinal lesions or multiple sclerosis, diazepam reduced the excitability of the monosynaptic arc. This action did not appear to result from a reduction in fusimotor drive. Diazepam also reduced the tonic vibration reflex in this group. It is postulated that these effects may be due to a supraspinal action of the drug.

The effect of diazepam on presynaptic inhibition in patients with complete and incomplete spinal cord lesions

The effect of diazepam on presynaptic inhibition in man has been examined in 5 patients with complete spinal transections and 7 patients with incomplete lesions. The inhibition of the H reflex by vibration applied to the tendo Achilles was used to assess presynaptic inhibition of the Ia monosynaptic pathway. Diazepam increased this inhibition in the patients with incomplete lesions, but had no significant effect on the inhibition in the patients with complete spinal transections. Evidently diazepam can enhance presynaptic inhibition in man. The effect, however, cannot be demonstrated in patients with longstanding complete spinal lesions possibly because of some alteration in the segmental presynaptic inhibitory mechanism in this group.