[Establishment and validation of clinical prediction model for steroid-resistant nephrotic syndrome in children]

Objective: To identify the clinically relevant factors of steroid-resistant nephrotic syndrome (SSNS) in children and establish a predictive model followed by verifying its feasibility. Methods: A retrospective analysis was performed in a total of 111 children with nephrotic syndrome admitted to Children's Hospital of ShanXi from January 2016 to December 2021. The clinical data of general conditions, manifestations, laboratory tests, treatment, and prognosis were collected. According to the steroid response, patients were divided into SSNS and steroid resistant nephrotic syndrome (SRNS) group. Single factor Logistic regression analysis was used for comparison between the 2 groups, and variables with statistically significant differences were included in multivariate Logistic regression analysis. The multivariate Logistic regression analysis was used to identify the related variables of children with SRNS. The area under the receiver operating characteristic curve (ROC), the calibration curve and the clinical decision curve were used to evaluate its effectiveness of the variables. Results: Totally 111 children with nephrotic syndrome was composed of 66 boys and 45 girls, aged 3.2 (2.0, 6.6) years. There were 65 patients in the SSNS group and 46 in the SRNS group.Univariate Logistic regression analysis showed that the 6 variables, including erythrocyte sedimentation rate, 25-hydroxyvitamin D, suppressor T cells, D-dimer, fibrin degradation products, β2-microglobulin, had statistically significant differences between SSNS and SRNS groups (85 (52, 104) vs. 105 (85, 120) mm/1 h, 18 (12, 39) vs. 16 (12, 25) nmol/L, 0.23 (0.19, 0.27) vs. 0.25 (0.20, 0.31), 0.7 (0.6, 1.1) vs. 1.1 (0.9, 1.7) g/L, 3.1 (2.3, 4.1) vs. 3.3 (2.7, 5.8) g/L, 2.3 (1.9,2.8) vs. 3.0 (2.5, 3.7) g/L, χ²=3.73, -2.42, 2.24, 3.38, 2.24,3.93,all P<0.05), were included in the multivariate Logistic regression analysis. Finally, we found that 4 variables including erythrocyte sedimentation rate, suppressor T cells, D-dimer and β2-microglobulin (OR=1.02, 1.12, 25.61, 3.38, 95%CI 1.00-1.04, 1.03-1.22, 1.92-341.04, 1.65-6.94, all P<0.05) had significant correlation with SRNS. The optimal prediction model was selected. The ROC curve cut-off=0.38, with the sensitivity of 0.83, the specificity of 0.77 and area under curve of 0.87. The calibration curve showed that the predicted probability of SRNS group occurrence was in good agreement with the actual occurrence probability, χ²=9.12, P=0.426. The clinical decision curve showed good clinical applicability. The net benefit is up to 0.2. Make the nomogram. Conclusions: The prediction model based on the 4 identified risk factors including erythrocyte sedimentation rate, suppressor T cells, D-dimer and β2-microglobulin was suitable for the early diagnosis and prediction of SRNS in children. The prediction effect was promising in clinical application.

Metabolic engineering of Corynebacterium glutamicum for efficient production of optically pure (2R,3R)-2,3-butanediol

Background

2,3-butanediol is an important platform compound which has a wide range of applications, involving in medicine, chemical industry, food and other fields. Especially the optically pure (2R,3R)-2,3-butanediol can be employed as an antifreeze agent and as the precursor for producing chiral compounds. However, some (2R,3R)-2,3-butanediol overproducing strains are pathogenic such as Enterobacter cloacae and Klebsiella oxytoca.

Results

In this study, a (3R)-acetoin overproducing C. glutamicum strain, CGS9, was engineered to produce optically pure (2R,3R)-2,3-butanediol efficiently. Firstly, the gene bdhA from B. subtilis 168 was integrated into strain CGS9 and its expression level was further enhanced by using a strong promoter P_sod and ribosome binding site (RBS) with high translation initiation rate, and the (2R,3R)-2,3-butanediol titer of the resulting strain was increased by 33.9%. Then the transhydrogenase gene udhA from E. coli was expressed to provide more NADH for 2,3-butanediol synthesis, which reduced the accumulation of the main byproduct acetoin by 57.2%. Next, a mutant atpG was integrated into strain CGK3, which increased the glucose consumption rate by 10.5% and the 2,3-butanediol productivity by 10.9% in shake-flask fermentation. Through fermentation engineering, the most promising strain CGK4 produced a titer of 144.9 g/L (2R,3R)-2,3-butanediol with a yield of 0.429 g/g glucose and a productivity of 1.10 g/L/h in fed-batch fermentation. The optical purity of the resulting (2R,3R)-2,3-butanediol surpassed 98%.

Conclusions

To the best of our knowledge, this is the highest titer of optically pure (2R,3R)-2,3-butanediol achieved by GRAS strains, and the result has demonstrated that C. glutamicum is a competitive candidate for (2R,3R)-2,3-butanediol production.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12934-022-01875-5.

Engineering central pathways for industrial-level (3R)-acetoin biosynthesis in Corynebacterium glutamicum

BACKGROUND

Acetoin, especially the optically pure (3S)- or (3R)-enantiomer, is a high-value-added bio-based platform chemical and important potential pharmaceutical intermediate. Over the past decades, intense efforts have been devoted to the production of acetoin through green biotechniques. However, efficient and economical methods for the production of optically pure acetoin enantiomers are rarely reported. Previously, we systematically engineered the GRAS microorganism Corynebacterium glutamicum to efficiently produce (3R)-acetoin from glucose. Nevertheless, its yield and average productivity were still unsatisfactory for industrial bioprocesses.

RESULTS

In this study, cellular carbon fluxes in the acetoin producer CGR6 were further redirected toward acetoin synthesis using several metabolic engineering strategies, including blocking anaplerotic pathways, attenuating key genes of the TCA cycle and integrating additional copies of the alsSD operon into the genome. Among them, the combination of attenuation of citrate synthase and inactivation of phosphoenolpyruvate carboxylase showed a significant synergistic effect on acetoin production. Finally, the optimal engineered strain CGS11 produced a titer of 102.45 g/L acetoin with a yield of 0.419 g/g glucose at a rate of 1.86 g/L/h in a 5 L fermenter. The optical purity of the resulting (3R)-acetoin surpassed 95%.

CONCLUSION

To the best of our knowledge, this is the highest titer of highly enantiomerically enriched (3R)-acetoin, together with a competitive product yield and productivity, achieved in a simple, green processes without expensive additives or substrates. This process therefore opens the possibility to achieve easy, efficient, economical and environmentally-friendly production of (3R)-acetoin via microbial fermentation in the near future.

Curtailing unnecessary vancomycin usage in a hospital with high rates of methicillin resistant Staphylococcus aureus infections

AIMS

To implement and monitor the effectiveness of a strategy to curb unnecessary use of vancomycin and teicoplanin for inpatients in a teaching hospital/tertiary referral centre where 33% of S. aureus isolates (72% from ICU patients) were methicillin resistant.

METHODS

A sample of 182 vancomycin/teicoplanin inpatient prescriptions surveyed, revealed that only 31 (17%) conformed with Centre for Disease Control (CDC) guidelines. Following education (ward-rounds, bulletins) on appropriate CDC based guidelines for prescribing glycopeptides directed at relevant clinicians, 'Immediate Concurrent Feedback' (ICF) was gradually deployed throughout the hospital. This entailed review of respective inpatient records on the next working day. If the indication was deemed not to conform with our guidelines, the prescriber was issued a memo (copied to the supervising doctor). Each memo detailed the 'errant' incident, listed appropriate indications and explicitly advised desisting from such prescribing and suggested alternative therapy if necessary. Corresponding glycopeptide usage data for our hospital and others in Hong Kong were retrieved and analysed as were samples of records of our inpatients with staphylococcal septicaemia (pre and during ICF).

RESULTS

Compared with baseline values, during 2 years of ICF, inpatient prescribing of vancomycin and teicoplanin deemed to conform increased to 71% (773/1086); difference 54% (P < 0.0001, 95% CIs 47-62%). Corresponding average monthly usage (DDDs/1000 admissions) decreased from 76 (pre-ICF) to 45; mean difference 31 (P < 0.0001, 95% CIs 24, 38). Mortality from staphylococcal bacteraemia remained unchanged. No comparable changes in glycopeptide usage ensued in comparator hospitals.

CONCLUSIONS

ICF can be used safely to curb irrational overuse of vancomycin and teicoplanin in a hospital with high methicillin resistant S. aureus infection rates.

Increasing use of inhaled steroids associated with declining asthma mortality

Increasing worldwide asthma prevalence and mortality has led to greater advocacy of inhaled agents, especially steroids. To determine whether corresponding drug usage trends had ensued locally, wholesale data (expressed as defined daily doses (DDDs)/1000 inhabitants/day) were compared for inclusive periods 1984-1986 and 1992-1994. Whereas absolute usage of anti-asthmatics increased by 79%, proportional inhaled usage increased markedly, especially of steroids (571%) and in hospitals. An odds ratio trend analysis revealed asthma mortality from 1992 onward had declined, particularly in males (p < 0.001). In Hong Kong, despite increasing asthma prevalence, more intensive use of anti-asthmatic drugs (especially inhaled steroids) was associated with declining asthma mortality.

Antiulcer drug prescribing in hospital successfully influenced by "immediate concurrent feedback"

OBJECTIVE

To determine whether immediate concurrent feedback (ICF) focused on inpatient omeprazole prescribing achieved more rational and cost-effective antiulcer drug prescribing and usage.

METHODS

In a 1400-bed teaching hospital, an audit (by specially trained personnel) was conducted to monitor inpatient prescribing of omeprazole (1) in preference to H2-antagonists and other drugs according to agreed criteria (Helicobacter pylori eradication, severe reflux esophagitis, rapid ulcer healing deemed urgent because of severe symptoms or complications, high-dose steroid therapy of > or =30 mg/day prednisolone) and (2) appropriateness of intravenous dosing (oral route not feasible or contraindicated). After baseline monitoring for 1 month, followed by relevant antiulcer drug therapy education, ICF was instituted for 1 year. This entailed explanatory memoranda requesting a change in prescribing issued to the respective medical teams of patients whose omeprazole prescription did not "conform." The main outcomes of the study were omeprazole prescription numbers per month and the proportion conforming, defined daily doses of antiulcer drugs used and corresponding expenditures, and pertinent antiulcer drug utilization data from 9 other local hospitals.

RESULTS

Baseline omeprazole prescribing conformed in 32 of 173 (18%) of the patients compared with 451 of 546 (83%) during institution of ICF (P < 0001; chi2 test). Correspondingly, average overall omeprazole and ranitidine usage (inpatient and outpatient) and expenditure decreased (44% and 45%, respectively); collectively, use of less expensive alternatives increased about 61%. Estimated savings averaged about HK$150,000 ($20,000) per month. No comparable changes in usage were noted in 9 other local hospitals.

CONCLUSION

Regarding hospital antiulcer drugs, this ICF strategy was associated with more rational prescribing and usage, and an important saving of resources.

Bronchodilator responses to salbutamol using diskhaler versus metered-dose inhaler

In adults inhaling salbutamol via metered-dose inhalers (MDls) 200 microg doses are recommended, but with diskhalers the manufacturer advocates 400 rather than 200 microg doses. To assess this advice, a partially double-blind, placebo-controlled salbutamol dose response, crossover study (also incorporating MDI doses) was conducted in 12 mild/moderate asthmatics. After active treatment, mean peak expiratory flow rate (PEFR) increments yielded no clinically or statistically significant differences; compared to placebo, respective median differences in PEFR increments (95% Cls) were 10 (-10, 50), 20 (0, 50), and 15 (0, 30) following 400 and 200 microg via diskhalers and 200 microg via MDls. Diskhalers are a suitable alternative for patients with poor MDI technique, but the use of 400 rather than 200 microg salbutamol doses is not supported by evidence.

Inability of physicians to use metered-dose inhalers

The effectiveness of antiasthmatic therapy with metered-dose inhalers (MDIs) is usually limited by defective inhalational technique. This study surveyed the MDI inhalation performance and knowledge of 100 physicians whose performance (demarcated into six stages) and knowledge scores correlated (r = 0.33, p < 0.001). Inhalation performance scores for shaking the canister, full expiration prior to using the MDI, breath holding thereafter, and positioning of the mouth-piece correlated with their corresponding knowledge scores (p < or = 0.02). Training of physicians entailing actual instruction and supervision of inhalational maneuvers may enhance the ability of doctors to use MDIs and facilitate better patient supervision.

Hospital antibiotic prescribing successfully modified by 'immediate concurrent feedback'

1. To determine the effectiveness of ongoing immediate concurrent feedback (ICF) in minimizing 'inappropriate' sultamicillin or co-amoxiclav prescribing via the parenteral route (i.e. when the oral route was accessible and not contraindicated), a prospective controlled audit was carried out on hospital inpatients over a 20 month period. 2. After an education programme to promote oral rather than unnecessary intravenous (i.v.) use of sultamicillin, co-amoxiclav and certain other drugs, an ongoing ICF strategy was instituted. 3. ICF entailed issue of memos on the following day to prescribers of i.v. sultamicillin or co-amoxiclav for inpatients in whom this route was deemed 'inappropriate', by a specially trained nurse using strict objective criteria. The memos recommended oral prescribing (particularly of co-amoxiclav, currently the less expensive alternative). 4. After starting ICF, there were consistent, clinically and statistically significant reductions in the monthly proportions of (i) admissions prescribed i.v. sultamicillin or co-amoxiclav (38% P < 0.001), (ii) those in whom the route was 'inappropriate' (75%, P < 0.001), and (iii) corresponding ratios of i.v./oral usage and expenditure, oral sultamicillin/co-amoxiclav usage and expenditure, as well as total and per admission expenditure on i.v. forms (> or = 43%, P < 0.01). 5. For i.v. cefuroxime (for which there was no ICF) and its oral counterpart cefuroxime-axetil, there were no comparable changes in usage or expenditure. 6. This simple, ongoing ICF strategy was effective and well accepted; estimated net monthly savings being HK$26-30,000.

Investigation of nimodipine pharmacokinetics in Chinese patients with acute subarachnoid haemorrhage

Nimodipine pharmacokinetics was investigated in 12 Chinese patients with acute subarachnoid haemorrhage receiving an IV infusion of 1.6 or 2 mg/h (based on estimated body weight) for 10 days. Peripheral venous blood samples were collected for up to 4 days and plasma nimodipine was assayed by GC/ECD. The mean value was taken as the steady state concentration (Css) and Clearance (CL) (hourly dose/Css) was calculated. Eight survivors were given oral nimodipine (60 or 90 mg) every 6h (based on body weight), blood was sampled over 6 h and the plasma nimodipine level determined. The values for Css, CL and CL.kg-1 were 33.5 micrograms.l-1, 58 l.h-1 and 1.0 l.h-1 x kg-1 respectively; in survivors receiving the drug orally, bioavailability of the 30 mg tablet was 9%. In one very sick patient given crushed tablets by naso-gastric tube, the AUC was very low; in vitro studies indicated that adsorption of nimodipine by the tubing was unlikely to have been the cause. The pharmacokinetic findings in Chinese patients are comparable to previously reported values in Caucasians.

Treatment of acute cortical infarct with intravenous glycerol. A double-blind, placebo-controlled randomized trial

BACKGROUND AND PURPOSE

This clinical trial investigates the effectiveness of intravenous glycerol therapy in patients with acute cortical infarction in whom intracerebral hemorrhage was rigorously excluded.

METHODS

Within 48 hours of symptoms from their first ischemic stroke, 113 hospital inpatients were randomized into the trial, provided that hemorrhage was excluded by computed tomography and informed consent was obtained. Patients were stratified into alert, semicoma, and coma groups using the Glasgow Coma Scale. Treatment was allocated according to a double-blind, randomized protocol; 56 patients received 500 mL of 10% glycerol in saline over 4 hours on 6 consecutive days, and 57 patients received corresponding placebo treatment with saline. Using a variety of objective scoring systems, patient follow-up was up to 6 months.

RESULTS

Corresponding measures of outcome in the glycerol and placebo groups were similar. At 6 months, respective mortality rates were 17 of 56 and 16 of 57, and mean +/- SD improvements in scores were 9.98 +/- 14.40 vs 10.51 +/- 12.68 (long-term), 1.12 +/- 7.20 vs 1.57 +/- 6.30 (prognostic), -1.94 +/- 5.53 vs -2.06 +/- 5.34 (Glasgow Coma Scale), and 21.72 +/- 23.40 vs 11.94 +/- 18.10 (Barthel Index rating in survivors). Hemolysis (generally subclinical) was the only adverse effect.

CONCLUSIONS

There was no clinically or statistically significant difference in outcome between the groups; a trend toward greater functional recovery among survivors was evident after treatment with glycerol.

An audit of antiasthmatic drug inhalation technique and understanding

Inhaled rather than oral antiasthmatic therapy is accepted as more advantageous but depends on patient technique and understanding. In 74 asthmatic outpatients, technique using metered-dose inhaler (MDI) was poor; in 56 patients inhaling beta-agonist, the mean peak expiratory flow rate (PEFR) increase was only 15 L/min (6%) greater than in 18 controls, p < 0.05, 95% confidence intervals 2-27 L/min or 2-11%. Tilting the head back and actuation "stopping" inspiration produced the least favorable PEFR responses; taken together, regression analysis yielded a statistically significant negative correlation with absolute or percentage PEFR change (R2 = 0.15; p < 0.02). Patients were unclear about which drugs to inhale as required or regularly. Among 19 patients reassessed inhaling beta-agonist, only 8 had baseline PEFR values within 10% of each other during both assessments. In the latter, the mean postinhalation PEFR increase was 36 L/min (or 13%) greater than the corresponding increase (or % change) at first assessment, p = 0.05 (0.08), 95% confidence intervals 0-73 L/min (-2 to 29%). Thus, MDI users should avoid tilting the head back, actuation stopping inhalation, and be more aware of prophylactic (steroid) versus symptomatic (beta-agonist) treatment.

Treatment of acute cerebral hemorrhage with intravenous glycerol. A double-blind, placebo-controlled, randomized trial

BACKGROUND AND PURPOSE

Hitherto, treatment of acute cerebral hemorrhage with intravenous glycerol has not been evaluated in rigorous clinical studies with sufficient patient numbers.

METHODS

We undertook a double-blind, stratified and randomized, placebo-controlled clinical trial. Only patients with a first stroke admitted to the hospital within 24 hours after onset of symptoms were recruited, provided computed tomography confirmed hemorrhage and informed consent was obtained. After stratification into alert, semicoma, and coma subgroups using the Glasgow Coma Scale, 107 patients received active treatment (500 ml of 10% glycerol in saline by intravenous infusion over 4 hours on 6 consecutive days) and 109 were given corresponding saline treatment. Using a variety of objective scoring systems, patients were followed up for up to 6 months.

RESULTS

At follow-up, all measures of outcome in the treated and control groups were very similar. At 6 months, respective mortality rates were 37 of 107 and 33 of 109. Corresponding mean +/- SD improvements in Scandinavian Stroke Study Group scores were 8.35 +/- 16.9 versus 11.55 +/- 15.6 (long-term) and 0.64 +/- 7.3 versus 2.40 +/- 6.9 (prognostic), and improvements in the Barthel Index ratings were 10.72 +/- 24.7 versus 13.95 +/- 23.3, respectively. Glasgow Coma Scale score improvements in the survivors were 0.81 +/- 1.5 and 1.16 +/- 1.7 in the treated and control groups, respectively. Hemolysis (generally subclinical) was the only adverse effect of glycerol noted.

CONCLUSIONS

In the absence of any clinically or statistically significant difference in outcome between the treated and control groups, this trial provides no justification for glycerol therapy following acute cerebral hemorrhage.

Audit exposes flawed blood sampling for "digoxin levels"

Therapeutic "digoxin level" monitoring in selected wards was audited. Time elapsing between the last dose and blood sampling was considered appropriate if greater than or equal to 6 h. If such details were not entered on the requisition, the maximum time elapsing was estimated as "appropriate" or "inappropriate" from the time samples were logged into the laboratory and the time the last dose was entered in the patient's treatment sheet. In 22 requisitions detailing sampling time, nine were considered inappropriate. In an additional 150 instances, timing was estimated as inappropriate in 45. Among the 118 requests where timing (estimated or labelled) was appropriate, available plasma digoxin concentrations yielded a mean of 1.0 nM, compared to 1.6 nM in the corresponding 54 patients with premature sampling; this difference was both clinically and statistically significant (95% confidence limits 0.8-1.2 and 1.3-1.9 nM, respectively, p less than 0.001). Premature blood sampling for digoxin levels was common and associated with higher concentrations than when appropriate. Such inappropriate timing may not have serious consequences, but digoxin levels are a matter of record and are used for teaching; due attention to timing could provide more reliable information and avoid wasting valuable resources.

Actions of FRC-8653 on smooth muscle cells of the rabbit mesenteric artery

In ring preparations of the rabbit mesenteric artery, the Ca-contraction, but not the noradrenaline (NA)-contraction, was inhibited by FRC-8653 (10(-9)-10(-5) M) in a concentration-dependent manner, although with a potency 50-100 times weaker than that of nicardipine. The actions of FRC-8653 on Ca-contraction appeared more slowly (over 1 hr) than those of nicardipine. FRC-8653 (up to 10(-5) M) and nicardipine (up to 10(-7) M) did not change the resting membrane potential of smooth muscles. The amplitude of the evoked excitatory junction potential (e.j.p.) was inhibited by FRC-8653, but not by nicardipine, with no alteration in the facilitation process of the e.j.p.s. The inhibition by FRC-8653 of the e.j.p. appeared rapidly and was reversible. FRC-8653 inhibited the membrane depolarization of smooth muscles elicited by ATP, but not by NA or high [K+]o solution. ATP-induced contractions were also inhibited by FRC-8653. The amplitudes of action potentials evoked by current stimuli were decreased by FRC-8653, with no significant change in the electrotonic potentials. Thus, FRC-8653 has properties similar to those of the dihydropyridine Ca-antagonists, but differs from them in that 1) its inhibitory actions on Ca influx appear slowly and 2) sympathetic transmission is inhibited, possibly by inhibition of the postjunctional events for e.j.p. generation.

Recognition of the tRNA-like structure in tobacco mosaic viral RNA by ATP/CTP:tRNA nucleotidyltransferases from Escherichia coli and Saccharomyces cerevisiae

The 3'-terminal tRNA-like structure of the tobacco mosaic virus RNA interacts with ATP/CTP:tRNA nucleotidyltransferases from Escherichia coli or yeast in much the same manner as do tRNAs. Primary sites of interaction cluster near the 3' end and in the loop proposed to be analogous to the psi-loop of a tRNA. Some modified bases in the tRNA-like structure inhibit interaction with nucleotidyltransferase, yet the analogous bases in a tRNA do not. The location of some of these nucleotides within the analog to the psi-loop suggests that this structure differs slightly from its counterpart in a tRNA. The location of other such bases in the helical stem near the 3' end can be explained if the pseudoknot is disrupted by these modified bases or if the tertiary structure of the RNA is altered in the enzyme-RNA complex. A partially denatured secondary structure that persists on denaturing gels is proposed.

Lack of association between slow acetylator status and spontaneous lupus erythematosus

The Chinese in Southeast Asia are recognized as a population group that has a relatively high prevalence of rapid "acetylators" and a relatively high incidence of systemic lupus erythematosus. This study was designed to evaluate the possibility that there were environmental lupus erythematosus provocative substances eliminated by acetylation that resulted in a preponderance of slow acetylators among patients with the disease. We compared acetylator status in 36 Chinese women with mild, stable, and confirmed lupus erythematosus and 36 healthy control subjects matched for age, sex, and ethnic origin. Acetylator status was determined by use of HPLC to assay 5-acetylamino-6-formylamino-3-methyluracil/methylxanthine (AFMU/MX) and AFMU/(AFMU + MX) ratios in urine 1 to 4 hours after drinking a strong cup of coffee (caffeine). By use of parametric and nonparametric methods of analysis, the frequency distribution of AFMU/MX and AFMU/(AFMU + MX) ratios in both the patients and control subjects were determined to be very similar. Thus there was no association between slow acetylator status and lupus erythematosus in the study subjects.

Investigation of intravascular haemolysis during treatment of acute stroke with intravenous glycerol

1. In patients with acute strokes entering a large ongoing randomised double-blind controlled trial of intravenous glycerol therapy, the extent and pathogenesis of any ensuing haemolysis were evaluated using standard clinical investigations and in vitro techniques. 2. Twenty patients received 10% glycerol in saline (500 ml over 4 h on 6 consecutive days) and 15 received corresponding control treatment with saline. 3. Intravascular haemolysis was evident after the first infusion; compared with the controls the glycerol group had i) a greater mean reduction in serum haptoglobin concentration (P less than .05), and ii) a greater proportion exhibiting haemoglobinaemia (P = 0.03). 4. After 6 days of glycerol treatment, the mean reduction in haemoglobin concentration was only 0.8 g more than in controls; this difference being neither clinically nor statistically significant. 5. Glycerol therapy was not associated with haemoglobinuria, renal insufficiency or disseminated intravascular coagulation. 6. Exposure of red blood cells to 1-10% glycerol in vitro did not induce haemolysis per se; on re-exposure to lower concentrations lysis ensued provided a minimum osmotic gradient was present. 7. Whilst taking standard dosage regimes of glycerol, the stroke patients we studied manifested a degree of intravascular haemolysis but its consequences were not clinically significant; lysis probably ensued after venous blood acquiring high glycerol concentrations mixed with blood containing little or no glycerol.

Cephalosporin and aminoglycoside utilization in different parts of the world

Cephalosporin and aminoglycoside utilization in Hong Kong during 1984, 1985 and 1986, were evaluated from wholesale data and compared with corresponding Swedish statistics and with UK data from a survey of non-hospital prescriptions. Details regarding each drug and category were collated, adjusted for population and if appropriate expressed as defined daily doses (DDDs)/1000 inhabitants/day. With respect to cephalosporins: (a) overall sales (especially those of the newer and more expensive parenteral drugs) were increasing; (b) parenteral sales were much larger in Hong Kong hospitals than in the community (up to about 106 versus 16 kg/million inhabitants/year respectively), but in Sweden they were comparable (up to about 38 and 41 kg/million inhabitants/year respectively); (c) non-hospital oral utilization appeared greater in the UK than in Sweden and Hong Kong (up to about 0.7, 0.4 and 0.4 DDDs/1000 inhabitants/day respectively); (d) oral sales to hospitals were greater in Hong Kong than Sweden (up to 0.3 compared to 0.1 DDDs/1000 inhabitants/day respectively) and (e) oral paediatric formulations (liquids) were most popular in Hong Kong, a higher proportion of children in Hong Kong being one possible reason. Non-hospital sales of gentamicin and kanamycin in Hong Kong were much greater than in Sweden (up to about 0.20 and 0.06 vs. 0.01 and 0.00 DDDs/1000 inhabitants/day respectively), whereas UK utilization appeared almost non-existent. Topical neomycin sales in Hong Kong were much more popular than in Sweden (up to about 60 vs. 9 g/million inhabitants/day). These regional differences in antibiotic utilization may be related to respective health care systems (and thus the affordability and availability of drugs) and prescribing preferences (cultural and/or promoted by drug companies), quite apart from possible differences in drug efficacy, drug tolerance and the prevalence and severity of various infections.

Pattern of anti-asthmatic drug utilization in Hong Kong compared to other parts of the world

Inhaled drugs are now considered first line agents for the treatment of asthma, whereas oral beta-agonists, theophylline and its derivatives have been relegated to a secondary role. To determine whether current prescribing in Hong Kong conforms to these recommendations, we have evaluated anti-asthmatic drug utilization in the territory as reflected by 1984-86 drug sales (courtesy Medical and Health Department, Hong Kong). Sales/prescription statistics were also obtained from corresponding agencies of other governments and from published literature. If appropriate, data for comparison was expressed as defined daily doses (DDDs) per 1000 inhabitants per day. In contrast to the pattern of utilization in several developed nations, in Hong Kong (a) oral anti-asthmatic agents (particularly beta agonists) were more commonly utilized than inhaled drugs, and (b) inhaled therapy mainly consisted of non-selective beta-agonists, steroids being very rare. Further education is required to improve anti-asthmatic drug utilization patterns in the community.

An assessment of drug information sheets for diabetic patients: only active involvement by patients is helpful

Insulin/sulphonylurea-treated diabetics attending a busy university diabetic clinic were studied to determine whether issuing drug information sheets and/or age influenced understanding and behaviour regarding their disease and its treatment, especially with respect to avoiding hypoglycaemia. Patients were each asked 10 basic questions (each correct answer scoring 1), stratified by age (20 were less than or equal to 45 years and 91 greater than 45 years). According to a single-blind randomised protocol, they were issued or not issued with drug information sheets (providing information to correctly answer all 10 questions). After 2-3 months, 107 (88 aged greater than 45 years) were retested and asked whether they recalled an information sheet, read it themselves or had it read to them. Whether or not patients received sheets, corresponding mean aggregate scores were very similar in both age groups and there was no correlation with age. Second test scores yielded clinically and statistically significant increments in both the sheet and no sheet groups, respective mean aggregate scores increasing from 4.48 to 5.80 and 5.14 to 6.27 (P less than 0.001). Among patients issued with sheets, 32 who recalled reading them achieved the greatest improvement in mean scores (4.53 to 6.16, P less than 0.001). Active interaction/communication (participation in first test, recall and reading of information sheet) had a favourable educational impact irrespective of age, but merely issuing drug information sheets had no benefit.

Chemoprophylaxis with oral amoxycillin against bacterial endocarditis: when should second doses be administered after dentistry?

The adequacy of serum bactericidal activity after oral amoxycillin given as prophylaxis against infective endocarditis was studied using a double blind randomised protocol in healthy volunteers having dentistry. One hour before their procedure 38 patients received 3 g amoxycillin syrup and 12 received matching placebo. Venous blood samples were drawn before and one and nine hours after dosing and serum amoxycillin concentrations determined using a standard bioassay. Samples containing amoxycillin had inhibitory titres measured against two reference isolates of viridans streptococci known to have caused infective endocarditis. The susceptibility to amoxycillin of one strain was high and the other low, respective minimal bactericidal and inhibitory concentrations being 0.08 and 0.04 mumol/l (0.03 and 0.015 microgram/ml) and 2.74 and 1.37 mumol/l (1 and 0.5 microgram/ml). Amoxycillin was detected in only post-treatment samples of patients given the active drug. There were no significant correlations between one or nine hour drug concentrations and age or physical characteristics, nor was there any relation to preceding food consumption. Correlations between drug concentrations at one and nine hours were weak (r = 0.34; p less than 0.05), but between corresponding drug concentrations and serum inhibitory titres there were consistent correlations (r = 0.46-0.48; p less than 0.005). Against the low susceptibility reference isolate bactericidal amoxycillin concentrations were encountered in only 20 of the 38 nine hour samples (95% confidence limits 34% and 66%). When repeat doses of amoxycillin are indicated after dentistry they should be given about four hours later, not eight hours later as commonly practised.