Current Practice in Occupational Therapy for COVID-19 and Post-COVID-19 Conditions

The onset of the pandemic highlighted the need for a review of rehabilitation practices to ensure coordinated, effective, and efficient services for people affected by COVID-19. This paper reports on a global survey highlighting the delivery of occupational therapy services to people with COVID-19/post-COVID-19 condition (PCC) and makes recommendations to facilitate quality service delivery for this population. An online cross-sectional descriptive survey was developed and distributed to the global occupational therapy community via member organisations and communication channels of the World Federation of Occupational Therapists to collect information for this study. The survey obtained qualitative and quantitative data from respondents who were occupational therapists or occupational therapy assistants regarding (i) demographic characteristics, (ii) work experience with persons with COVID-19 and PCC, (iii) modes of working, (iv) education and training, (iv) occupational therapy intervention provided to persons with COVID-19 and PCC, and (v) the perceived quality of the occupational therapy services provided. Findings indicate that respondents provided a range of occupational therapy interventions for people affected by COVID-19/PCC aligned with evidence-based practice guidelines. While respondents identified a strong role for occupational therapy and generally rated their services as effective, issues related to the accessibility of their services impacted quality and user satisfaction. The study highlighted the need to advocate for access to occupational therapy to facilitate engagement in desired and needed occupations for COVID-19 survivors. Other recommendations emerging from the findings include the need to develop, disseminate, and use research evidence for guiding services for people with COVID-19/PCC, create quality service standards, and ensure the availability of necessary resources and supports such as referral pathways and screening criteria, availability of staff, training, personal protective equipment, and assistive devices and technology.

Annealing studies combined with low temperature emission Mössbauer spectroscopy of short-lived parent isotopes: Determination of local Debye-Waller factors

An extension of the online implantation chamber used for emission Mössbauer Spectroscopy (eMS) at ISOLDE/CERN that allows for quick removal of samples for offline low temperature studies is briefly described. We demonstrate how online eMS data obtained during implantation at temperatures between 300 K and 650 K of short-lived parent isotopes combined with rapid cooling and offline eMS measurements during the decay of the parent isotope can give detailed information on the binding properties of the Mössbauer probe in the lattice. This approach has been applied to study the properties of Sn impurities in ZnO following implantation of ¹¹⁹In (T_½ = 2.4 min). Sn in the 4+ and 2+ charge states is observed. Above T > 600 K, Sn²⁺ is observed and is ascribed to Sn on regular Zn sites, while Sn²⁺ detected at T < 600 K is due to Sn in local amorphous regions. A new annealing stage is reported at T ≈ 550 K, characterized by changes in the Sn⁴⁺ emission profile, and is attributed to the annihilation of close Frenkel pairs.

Descriptive epidemiology of coronavirus disease 2019 in Nigeria, 27 February-6 June 2020

The objective of this study was to describe the epidemiology of COVID-19 in Nigeria with a view of generating evidence to enhance planning and response strategies. A national surveillance dataset between 27 February and 6 June 2020 was retrospectively analysed, with confirmatory testing for COVID-19 done by real-time polymerase chain reaction (RT-PCR). The primary outcomes were cumulative incidence (CI) and case fatality (CF). A total of 40 926 persons (67% of total 60 839) had complete records of RT-PCR test across 35 states and the Federal Capital Territory, 12 289 (30.0%) of whom were confirmed COVID-19 cases. Of those confirmed cases, 3467 (28.2%) had complete records of clinical outcome (alive or dead), 342 (9.9%) of which died. The overall CI and CF were 5.6 per 100 000 population and 2.8%, respectively. The highest proportion of COVID-19 cases and deaths were recorded in persons aged 31-40 years (25.5%) and 61-70 years (26.6%), respectively; and males accounted for a higher proportion of confirmed cases (65.8%) and deaths (79.0%). Sixty-six per cent of confirmed COVID-19 cases were asymptomatic at diagnosis. In conclusion, this paper has provided an insight into the early epidemiology of COVID-19 in Nigeria, which could be useful for contextualising public health planning.

New role for crinamine as a potent, safe and selective inhibitor of human monoamine oxidase B: In vitro and in silico pharmacology and modeling

ETHNOPHARMACOLOGICAL RELEVANCE

The development of selective inhibitors of monoamine oxidase B (MAO-B) has been essential in treating Parkinson's disease. However, the apparent hepatotoxicity and drug-drug interactions of current inhibitors accentuate the need for the development of novel pharmacotherapies. Crossyne guttata (L.) D. & U. Müll-Doblies is used frequently by Rastafarian bush doctors to treat alcoholism, a disorder which is also accentuated by MAO.

OBJECTIVE

The study sought to isolate, identify and characterise the biologically active constituents of C. guttata based on their ability to inhibit the MAO enzymes.

MATERIALS AND METHODS

Column chromatography was used to isolate the biologically active alkaloids of C. guttata. The ability of the alkaloids to inhibit the biotransformation of 4-aminoantipyrine by the MAO enzymes was evaluated in vitro. In silico docking was conducted using AutoDock Vina server while the pharmacokinetic properties of the compounds were evaluated using SwissADME.

RESULTS

Chromatographic separation of an ethanolic fraction of C. guttata yielded the alkaloids crinamine 1 and epibuphanisine 2. 1 and 2 along with structurally related alkaloids haemanthamine 3 and haemanthidine 4 were evaluated for their ability to inhibit the action of isozymes of MAO in vitro. Alkaloids effected submicromolar IC₅₀ values against MAO-B, the most potent of which being crinamine 1 (0.014 μM) > haemanthidine 4 (0.017 μM) > epibuphanisine 2 (0.039 μM) > haemanthamine 3 (0.112 μM). Binding energies of the alkaloids correlated well with their inhibitory potential with crinamine displaying the best binding efficacy and binding energy score with MAO-B.

DISCUSSION AND CONCLUSION

Crinamine and epibuphanisine exhibited potent and selective inhibitory activity towards MAO-B. After comprehensive in silico investigations encompassing robust molecular docking analysis, the drug-like attributes and safety of the alkaloids suggest the crinamine is a potentially safe drug for human application.

Predictors of contraceptive use among adolescent girls and young women (AGYW) aged 15 to 24 years in South Africa: results from the 2012 national population-based household survey

BACKGROUND

Despite a variety of contraceptives being available for women in South Africa, a considerable number of adolescent girls and young women still face challenges in using them. This paper examines socio-demographic and behavioral predictors of using contraceptives among adolescent girls and young women (AGYW) aged 15 to 24 years.

METHODS

A secondary data analysis was conducted based on the 2012 population-based nationally representative multi-stage stratified cluster randomised household survey. Multivariate backward stepwise logistic regression model was used to examine socio-demographic and behavioural factors independently associated with contraceptive use amongst AGYW aged 15 to 24 years in South Africa.

RESULTS

Out of 1460 AGYW, 78% (CI: 73.9-81.7) reported using some form of contraceptives. In the model, contraceptive use was significantly associated with secondary education [OR = 1.8 (1.2-2.7), p = 0.005], having a sexual partner within 5 years of their age [OR = 1.8 (1.2-2.5), p = 0.002], and sexual debut at age 15 years and older [OR = 2.5 (1.3-4.6), p = 0.006]. The likelihood of association decreased with other race groups-White, Coloured, and Indians/Asians [OR = 0.5 (0.3-0.7), p = 0.001], being married [OR = 0.4 (0.2-0.7), p = 0.001], never given birth [OR = 0.7 (0.5-0.9), p = 0.045], coming from rural informal [OR = 0.5 (0.3-0.9), p = 0.010] and rural formal settlements [OR = 0.5 (0.3-0.9), p = 0.020].

CONCLUSIONS

Evidence suggest that interventions should be tailor-made to meet the needs of AGYW in order to, promote use and access to contraceptives. The results also suggest that family planning interventions should target those who had not given birth in order to reduce unplanned and or unintended pregnancies and associated risk factors. These findings contribute to public health discourse and reproductive health planning for these age groups in the country.

Bioassay-guided purification, GC-MS characterization and quantification of phyto-components in an antibacterial extract of Searsia lancea leaves

Phytocompounds in an aqueous methanol (70% MeOH) leaf extract of Searsia lancea were separated using liquid-liquid partitioning techniques and gravity-assisted column chromatography. The resultant fractions were screened for antibacterial properties (minimum inhibitory concentration, MIC) against four bacterial strains (Enterococcus faecalis, Klebsiella pneumoniae, Neisseria gonorrhoeae and Staphylococcus aureus). Bioactive fractions were purified using preparative thin layer chromatography (TLC) and subjected to further antibacterial screening. Phytocompounds in antibacterial sub-fractions were characterized and quantified using Gas Chromatography-Mass Spectrometry (GC-MS). An ethyl acetate sub-fraction purified from the aqueous methanol extracts of the leaves demonstrated potent antibacterial properties (MIC range: 31-61 µg/ml against E. faecalis and S. aureus). Based on GC-MS analysis, 81.5% of the sub-fraction consisted of broad-spectrum antibacterial compounds namely tetracosanol (43.98%) and nonadecanol (37.5%). Current research findings support the traditional use of S. lancea leaves to manage gastro-intestinal disorders and gonorrhoea.

Metagenomic sequencing at the epicenter of the Nigeria 2018 Lassa fever outbreak

The 2018 Nigerian Lassa fever season saw the largest ever recorded upsurge of cases, raising concerns over the emergence of a strain with increased transmission rate. To understand the molecular epidemiology of this upsurge, we performed, for the first time at the epicenter of an unfolding outbreak, metagenomic nanopore sequencing directly from patient samples, an approach dictated by the highly variable genome of the target pathogen. Genomic data and phylogenetic reconstructions were communicated immediately to Nigerian authorities and the World Health Organization to inform the public health response. Real-time analysis of 36 genomes and subsequent confirmation using all 120 samples sequenced in the country of origin revealed extensive diversity and phylogenetic intermingling with strains from previous years, suggesting independent zoonotic transmission events and thus allaying concerns of an emergent strain or extensive human-to-human transmission.

The inactivation of Ascaris suum eggs by short exposure to high temperatures

Ascaris sp. is the most prominent and resilient helminth of human health importance found in faecal sludge, making Ascaris sp. an ideal index organism for inactivation testing. Heat treatment destroys helminths,allowingfor safe handling and possible reuse of sludge. Technology developmentfocuses on rapid heating to minimize equipment size and cost. This study evaluates Ascaris suum eggs' viability with short heating time. Ascaris eggs were placed in a water bath at temperatures from 60 to 80 °C for various exposure times (5 seconds to 4 minutes) and were immediately processed and analysed via light microscopy. For all samples within these temperature and time ranges, less than 10% viable eggs were recovered. For 70, 75 and 80 °C, complete inactivation was observed for exposure time of 5 seconds and above.

The ASOS Surgical Risk Calculator: development and validation of a tool for identifying African surgical patients at risk of severe postoperative complications

BACKGROUND

The African Surgical Outcomes Study (ASOS) showed that surgical patients in Africa have a mortality twice the global average. Existing risk assessment tools are not valid for use in this population because the pattern of risk for poor outcomes differs from high-income countries. The objective of this study was to derive and validate a simple, preoperative risk stratification tool to identify African surgical patients at risk for in-hospital postoperative mortality and severe complications.

METHODS

ASOS was a 7-day prospective cohort study of adult patients undergoing surgery in Africa. The ASOS Surgical Risk Calculator was constructed with a multivariable logistic regression model for the outcome of in-hospital mortality and severe postoperative complications. The following preoperative risk factors were entered into the model; age, sex, smoking status, ASA physical status, preoperative chronic comorbid conditions, indication for surgery, urgency, severity, and type of surgery.

RESULTS

The model was derived from 8799 patients from 168 African hospitals. The composite outcome of severe postoperative complications and death occurred in 423/8799 (4.8%) patients. The ASOS Surgical Risk Calculator includes the following risk factors: age, ASA physical status, indication for surgery, urgency, severity, and type of surgery. The model showed good discrimination with an area under the receiver operating characteristic curve of 0.805 and good calibration with c-statistic corrected for optimism of 0.784.

CONCLUSIONS

This simple preoperative risk calculator could be used to identify high-risk surgical patients in African hospitals and facilitate increased postoperative surveillance.

CLINICAL TRIAL REGISTRATION

NCT03044899.

The time-temperature relationship for the inactivation of Ascaris eggs

A time-temperature plot presenting the inactivation of Ascaris eggs is expanded with additional literature data. The information is of value to designers and operators of sanitation equipment who have Ascaris inactivation as an objective.

Atomic-scale study of the amorphous-to-crystalline phase transition mechanism in GeTe thin films

The underlying mechanism driving the structural amorphous-to-crystalline transition in Group VI chalcogenides is still a matter of debate even in the simplest GeTe system. We exploit the extreme sensitivity of ⁵⁷Fe emission Mössbauer spectroscopy, following dilute implantation of ⁵⁷Mn (T½ = 1.5 min) at ISOLDE/CERN, to study the electronic charge distribution in the immediate vicinity of the ⁵⁷Fe probe substituting Ge (Fe_Ge), and to interrogate the local environment of Fe_Ge over the amorphous-crystalline phase transition in GeTe thin films. Our results show that the local structure of as-sputtered amorphous GeTe is a combination of tetrahedral and defect-octahedral sites. The main effect of the crystallization is the conversion from tetrahedral to defect-free octahedral sites. We discover that only the tetrahedral fraction in amorphous GeTe participates to the change of the Fe_Ge-Te chemical bonds, with a net electronic charge density transfer of  ~ 1.6 e/a₀ between Fe_Ge and neighboring Te atoms. This charge transfer accounts for a lowering of the covalent character during crystallization. The results are corroborated by theoretical calculations within the framework of density functional theory. The observed atomic-scale chemical-structural changes are directly connected to the macroscopic phase transition and resistivity switch of GeTe thin films.

Charge states and lattice sites of dilute implanted Sn in ZnO

The common charge states of Sn are 2+  and 4+. While charge neutrality considerations favour 2+  to be the natural charge state of Sn in ZnO, there are several reports suggesting the 4+  state instead. In order to investigate the charge states, lattice sites, and the effect of the ion implantation process of dilute Sn atoms in ZnO, we have performed ¹¹⁹Sn emission Mössbauer spectroscopy on ZnO single crystal samples following ion implantation of radioactive ¹¹⁹In (T _½  =  2.4 min) at temperatures between 96 K and 762 K. Complementary perturbed angular correlation measurements on ^111mCd implanted ZnO were also conducted. Our results show that the 2+  state is the natural charge state for Sn in defect free ZnO and that the 4+  charge state is stabilized by acceptor defects created in the implantation process.

Biological variability of superoxide dismutase and glutathione peroxidase in blood

The enzymatic antioxidant defences of mammalian cells include copper-zinc superoxide dismutase (SOD)(Cu Zn-SOD; EC 1.15.1.1) which catalyses the dismutation of superoxide anions (O2(.-)) to hydrogen peroxide(H(2), O(2))and a seleno-dependent glutathione peroxidase (GSH-px) (GSH-px; EC 1.11.1.9) which catalyses the degradation of H(2)O(2) to H(2)O and O(2). The measurement of these enzyme activities is often used as a possible biological index of oxidative stress in various clinical conditions. Complete understanding of such information requires knowledge of the random biological fluctuation of the enzyme activity which occurs in each individual. In the present investigation we examined this normal variability in 12 healthy volunteers (four women and eight men) aged 23-45 years, over 6 months. The intra-individual coefficients of variation (estimated using analysis of variance techniques) were 15% (SOD) and 13% (GSH-px). The analytical goal for imprecision was achieved for both enzymes, i.e. it was less than one half of the measured intra-individual variation. Both enzymes showed marked individuality, indicating that an individual's reference values are more useful than population-based data. The critical difference required for significant changes in serial results is 45% for SOD and 40% for GSH-px.

Oxidative stress and air pollution exposure during pregnancy: A molecular assessment

Chronic air pollution exposure during pregnancy can cause oxidative stress leading to adverse birth outcomes. The aim of this study was to assess and compare oxidative stress response in peripheral lymphocytes isolated from pregnant women from a highly industrialized locale (south Durban (SD); n = 50) and a control with lower air pollutant levels (north Durban (ND); n = 50). Oxidative stress response was measured by quantifying malondialdehyde (MDA) levels and a SuperArray gene panel. Mitochondrial function (adenosine triphosphate (ATP) levels and mitochondrial depolarization), DNA integrity (comet assay and mitochondrial DNA (mtDNA) viability) and DNA repair (OGG1) were assessed. Antioxidant response was assessed by quantification of glutathione (GSH) and SOD2, nuclear factor erythroid 2-related factor 2 (Nrf2) and uncoupling protein 2 (UCP2) protein and messenger RNA (mRNA) expression. Levels of MDA (p = 0.9), mitochondrial depolarization (p = 0.88), ATP (1.89-fold), SOD2 (1.23-fold) and UCP2 (1.58-fold) gene expression were elevated in the SD group with significantly higher UCP2 protein levels (p = 0.05) and longer comet tail length (p = 0.0004). The expression of Nrf2 protein (p = 0.03) and mRNA levels (-1.37-fold), GSH concentration (p < 0.0001), mtDNA amplification (-2.04-fold) and OGG1 mRNA (-2.78-fold) activity were decreased in the SD group. Of the 84 oxidative stress-related genes evaluated, 26 were differentially regulated. Pregnant women exposed to higher air pollutant levels showed increased markers for oxidative stress and compromised DNA integrity and repair.

A polymorphism in HLA-G modifies statin benefit in asthma

Several reports have shown that statin treatment benefits patients with asthma, however inconsistent effects have been observed. The mir-152 family (148a, 148b and 152) has been implicated in asthma. These microRNAs suppress HLA-G expression, and rs1063320, a common SNP in the HLA-G 3’UTR which is associated with asthma risk, modulates miRNA binding. We report that statins up-regulate mir-148b and 152, and affect HLA-G expression in an rs1063320 dependent fashion. In addition, we found that individuals who carried the G minor allele of rs1063320 had reduced asthma related exacerbations (emergency department visits, hospitalizations or oral steroid use) compared to non-carriers (p=0.03) in statin users ascertained in the Personalized Medicine Research Project at the Marshfield Clinic (n=421). These findings support the hypothesis that rs1063320 modifies the effect of statin benefit in asthma, and thus may contribute to variation in statin efficacy for the management of this disease.

Plants traditionally used individually and in combination to treat sexually transmitted infections in northern Maputaland, South Africa: antimicrobial activity and cytotoxicity

ETHNOPHARMACOLOGICAL RELEVANCE

Although medicinal plants are used extensively to treat sexually transmitted infections (STIs) in rural northern Maputaland, KwaZulu-Natal, the efficacy and safety of these plants have not previously been evaluated.

AIM OF STUDY

A study was designed to investigate the in vitro antimicrobial activity and cytotoxicity profiles of a selection (individual plants and selected combinations) of traditionally used plants in this study area.

MATERIALS AND METHODS

Aqueous and organic (dichloromethane: methanol, 1:1) extracts were prepared. Antimicrobial activity was assessed using the minimum inhibitory concentration (MIC) assay against the STI associated pathogens; Candida albicans ATCC 10231, Ureaplasma urealyticum clinical strain, Oligella ureolytica ATCC 43534, Trichomonas vaginalis clinical strain, Gardnerella vaginalis ATCC 14018 and Neisseria gonorrhoeae ATCC 19424. For the combination study, interactions were assessed using the fractional inhibitory concentration (ΣFIC). The plant species were assessed for safety using the 3-[4,5-dimethyl-2-thiazol-yl]-2,5-diphenyl-2H-tetrazolium bromide (MTT) cellular viability assay on the human embryonic kidney epithelial (Graham, HEK-293) cell line.

RESULTS

For the antimicrobial studies, U. urealyticum was the most sensitive of the six test organisms, with the aqueous extract of Ranunculus multifidus (0.02mg/ml) and the organic extract of Peltophorum africanum (0.04mg/ml) being the most antimicrobially active plant species studied. Sclerocarya birrea was found to have the broadest spectrum of activity (mean MIC of 0.89mg/ml). The only plant species to exhibit some degree of cytotoxicity against the kidney epithelial cell line was Kigelia africana (100µg/ml), with 22% and 16% cell death for the aqueous and organic extracts, respectively. Of the 13 combinations studied, several synergistic combinations were evident, the most prominent being the combination of Albizia adianthifolia and Trichilia dregeana (aqueous extract) with an ΣFIC value of 0.15 against O. ureolytica. Synergistic interactions were observed regardless of the ratio of the aqueous mixtures of the two plants. Syzygium cordatum and S. birrea (aqueous extract) was also a combination of interest, demonstrating synergistic (ΣFIC=0.42) interactions against O. ureolytica. This combination, however, also displayed some cytotoxicity towards the human epithelial cell line.

CONCLUSION

This study demonstrated that anecdotal evidence of plant use does not always correlate with in vitro activity. Furthermore, the toxicological profiling is of utmost importance as if not combined in its correct ratio can lead to potential adverse effects.

Fe charge state adjustment in ZnO upon ion implantation

The influence of the ion implantation process on the charge state of dilute (57)Fe impurities implanted as radioactive (57)Mn in ZnO is investigated by (57)Fe emission Mössbauer spectroscopy. One sample is additionally implanted with stable (23)Na impurities. Both Fe(2+) and Fe(3+) charge states are observed, and the Fe(3+)/Fe(2+) ratio is found to increase with the fluence of both (57)Mn/(57)Fe and (23)Na ions, demonstrating that the build-up of Fe(3+) is not related to the chemical nature of the implanted ions. The results are interpreted in terms of radiation damage induced changes of the Fermi level, and illustrate that the Fe(3+)/Fe(2+) ratio can be adjusted by ion implantation. The spin-lattice relaxation time for Fe(3+) in ZnO is found to be independent of the implantation fluence, and is evidently an intrinsic property of the system.

Maternal deaths following nevirapine-based antiretroviral therapy

We report 2 cases illustrating that it is too simplistic to link nevirapine (NVP) toxicity exclusively to individuals with immune preservation. Not enough is known about the mechanism of hepatotoxicity or cutaneous eruption to predict these events. This type of hypersensitivity reaction occurs rarely among HIV-exposed infants taking NVP prophylaxis or antiretroviral therapy (ART)-experienced adults with complete plasma viral load suppression. Conversely, HIV-uninfected adults and ART-naive pregnant women appear to be disproportionately affected by the adverse effects of NVP.

Antidiabetic, anti-oxidant and antimicrobial activities of Fadogia ancylantha extracts from Malawi

ETHNOPHARMACOLOGICAL RELEVANCE

Communities in Chilumba, Malawi use herbal tea prepared from Fadogia ancylantha Schweinf (Rubiaceae) leaves for the management of diabetes, hypertension and alleviation of symptoms of gastrointestinal disorders and pneumonia. The objective of the study was to evaluate the in vitro antidiabetic, anti-oxidant and antimicrobial activities of the crude extracts of the leaves prepared by using three different extraction methods.

MATERIALS AND METHODS

Each of the organic, cold and hot aqueous extracts of the herbal tea was evaluated for its effect on glucose uptake in C2C12 muscle and Chang cell lines. Metformin and insulin were used as positive controls. The anti-oxidant activity, based on neutralisation of DPPH free radicals, was determined spectrophotometrically. The Agar serial dilution method was utilised to determine the minimum inhibitory concentration (MIC) of the extracts for the selected fungal and bacterial strains.

RESULTS AND DISCUSSION

The organic extract (12.5μg/ml) exhibited the highest in vitro glucose uptake increases in Chang cells (181.24±0.29%) and C2C12 muscle cells (172.29±0.32%) while the hot and cold aqueous extracts gave lower uptakes, 145.94±0.37% and 138.70±0.52% in Chang cells respectively. At 100μg/ml, aqueous extracts gave significantly higher (p<0.01) anti-oxidant activity (range 85.78-86.29%) than their organic counterpart (68.16%). The minimum inhibitory concentration (156μg/ml) was obtained in the organic extract against the fungus Aspergillus fumigatus and moderate growth inhibition was observed with other test micro-organisms. The hot aqueous extract inhibited the growth of all test organisms except Pseudomonas aeruginosa. The cold aqueous extract was inactive against Pseudomonas aeruginosa and Candida albicans. The differences in the MIC values between the aqueous extracts seem to suggest that raised temperatures, as traditionally practised, facilitate the extraction of secondary bioactive metabolites.

CONCLUSION

These results show that Fadogia ancylantha extracts have high antidiabetic and anti-oxidant properties.

An antimicrobial investigation of plants used traditionally in southern Africa to treat sexually transmitted infections

AIM OF THE STUDY

Eighteen plants were assessed for antimicrobial activity against pathogens associated with prevalent urogenital/sexually transmitted infections. Plant selection was based on information obtained from the ethnobotanical literature.

MATERIALS AND METHODS

Dried plant material was submerged in a 1:1 mixture of methanol and dichloromethane for 24 h. Aqueous extracts were prepared by submerging dried plant material in sterile distilled water for 24 h followed by lyophilization. Essential oils were distilled from the two aromatic plant species (Tarchonanthus camphoratus and Croton gratissimus). Antimicrobial activity was assessed using the micro-well minimum inhibitory concentration (MIC) assay with specific modifications to facilitate fastidious growth of pathogens.

RESULTS

Tarchonanthus camphoratus (solvent extract) showed the most significant broad spectrum activity with MIC values ranging between 0.50 and 0.70 mg/ml against five of the six pathogens tested. Other noteworthy activity was found for Hypericum aethiopicum (root) at 0.3 mg/ml (Neisseria gonorrhoeae).Polygala fruticosa and the solvent root extract of Hypericum aethiopicum showed highest sensitivities towards Gardnerella vaginalis at 0.2 mg/ml. Efficacy of the solvent extracts against the pathogen Oligella ureolytica demonstrated antimicrobial activity (MIC values <or=1.0 mg/ml) for seven plant species. The highest activity noted against Ureaplasma urealyticum was for Psidium guajava (solvent extract) at 0.8 mg/ml. In general the aqueous extracts displayed mostly poor anti-STI activity. The most noteworthy susceptibility for the aqueous extracts was noted with the plant extract Syzygium cordatum (MIC value 0.1 mg/ml against Candida albicans). The most noteworthy activity for the essential oils was observed for Tarchonanthus camphoratus (0.8 mg/ml) against Oligella ureolytica.

CONCLUSIONS

Antimicrobial activity was observed for a number of the plant samples against at least one or more pathogen, thus validating the ethnobotanical use as an anti-infective to treat sexually transmitted diseases.

Interim report on pandemic H1N1 influenza virus infections in South Africa, April to October 2009: epidemiology and factors associated with fatal cases

We provide an interim report on pandemic H1N1 influenza activity in South Africa, with a focus on the epidemiology and factors associated with deaths. Following the importation of the virus on 14 July 2009, and the epidemic peak during the week starting 3 August, the incidence in South Africa has declined. A total of 12,331 cases and 91 deaths have been laboratory-confirmed as of 12 October 2009. Age distribution and risk groups were similar to those observed elsewhere. The median age of patients who died (33.5 years) was significantly higher than that of the non-fatal cases (15.0 years, p<0.01). The most common underlying conditions among fatal cases were infection with human immunodeficiency virus (17/32 tested) and pregnancy (25/45 women of reproductive age). Active tuberculosis coinfection was present in seven of 72 fatal cases. These findings should be taken into consideration when planning vaccination strategies for 2010.

Microbial community analysis of a full-scale membrane bioreactor treating industrial wastewater

A Kubotatrade mark submerged membrane bio-reactor was applied to treat wastewater from a sugar manufacturing industry. To achieve optimal results, fundamental and extended understanding of the microbiology is important. Fluorescence in situ hybridization was used to evaluate the microbial community present. The majority of cells visualized in the sludge flocs by staining with the DNA fluorochrome DAPI, hybridized strongly with a bacterial probe. Probes specific for the alpha-, beta-, and gamma-subclasses of proteobacteria and high G + C Gram positive bacteria were used to characterize the community structures by in situ hybridization. Sampling was carried out over 12 weeks and samples were fixed with 4% paraformaldehyde for gram positive organisms and ice cold ethanol for gram negative organisms. The activated sludge population usually constitutes about 80 to 90% of proteobacteria. However, in this study it was found that a relatively small amount of proteobacteria was present within the system. No positive hybridization signal was observed with any of the applied eubacterial family- level probes.

Thiopurine metabolite monitoring in paediatric inflammatory bowel disease

BACKGROUND

Measurement of thiopurine metabolite levels may be useful as a clinical tool to optimize thiopurine treatment of paediatric inflammatory bowel disease (IBD).

AIM

The authors evaluated correlations between 6-thioguanine nucleotide (6-TGN) and therapeutic response, metabolite levels and drug toxicity.

METHODS

Fifty-six paediatric IBD patients treated with thiopurines had 326 metabolite level measurements and were retrospectively reviewed. Clinical status and laboratory parameters were compared with metabolite levels.

RESULTS

There was significant correlation between 6-TGN levels and therapeutic response, with higher median 6-TGN levels among patients with therapeutic response than those with non-therapeutic response (194 vs. 146 pmol/8 x 10(8) RBC; P = 0.0004). Patients with 6-TGN levels >235 pmol/8 x 10(8) RBC were more likely to achieve therapeutic response than those below the cut-off (odds ratio, 2.5; 95% CI, 1.5-4.1). Patients who developed leukopenia tended to have higher median 6-TGN levels than those without leukopenia (261 vs. 160 pmol/8 x 10(8) RBC) but the difference was not statistically significant. There was no correlation between 6-methylmercaptopurine levels and hepatotoxicity. Two patients developed acute pancreatitis. Metabolite level measurements were helpful in identifying non-compliance in nine patients.

CONCLUSIONS

Monitoring of thiopurine metabolite levels is useful to guide and optimize dosing, as an adjunct to clinical judgement, blood count and liver biochemistry measurements to minimize the risk of drug toxicity and to confirm non-compliance.

Relation of the external branch of the superior laryngeal nerve to the superior pole of the thyroid gland: An anatomical study

The external branch of the superior laryngeal nerve (ELN) is intimately associated with the superior thyroid artery (STA) in relation to the superior pole of the thyroid gland, rendering it vulnerable to injury during the ligation of this vessel during thyroidectomy. Although most texts acknowledge the fact that the nerve is in close relation to the STA, there has not been an anatomical study to relate the position of the ELN to the superior pole of the thyroid gland. The aim of this study was to determine the shortest distance, from the most superior point of the thyroid gland, to the ELN. Bilateral micro-dissection on 43 adult cadavers, excluding those with thyroid pathology and previous thyroidectomies, was undertaken. The most superior point of the superior pole of the thyroid gland was identified and the shortest distance to the ELN was measured with a digital calliper (accuracy 0.01 mm). The metric study indicated a mean distance from the ELN to the superior pole of a normal sized thyroid gland of 5.76 mm (range: 2.00-11.26) on the right, and 6.17 mm (range: 2.78-13.48) on the left. From the literature, it is clear that the ELN may even be closer to the superior pole of an enlarged thyroid gland. The recommendation to stay on the substance of the superior pole of the thyroid gland when ligating the STA remains valid, as the nerve is extremely close in relation to the superior pole of the normal thyroid gland.

Associations between plasma antioxidants and hypertension in a community-based sample of 415 Australians aged 60-64

It has been suggested that increased oxidative stress may be both a cause as well as a consequence of hypertension. In vivo oxidation of low-density lipoproteins by oxygen-free radicals may increase hypertension-related atherogenesis, and antioxidants may be beneficial in this regard. Previous findings concerning associations between serum measures of antioxidants and hypertension have however been inconsistent. Plasma levels of beta-carotene, Vitamin A, E, uric acid, homocysteine and total antioxidant capacity, as well as two markers of oxidative stress, malondialdehyde (MDA) and protein carbonyls, were measured in morning fasting blood samples provided by 415 Australians aged 60-64 years, selected randomly from the community. Participants also provided information on sociodemographic attributes, mental and physical health, and provided two measures of resting blood pressure, allowing a diagnosis of definite or borderline hypertension. Those with hypertension had lower levels of beta-carotene and higher levels of uric acid and MDA compared to normotensive participants. The last two of these associations persisted when the analyses controlled for lifestyle and health factors. The findings from this study offer limited support for the proposition that lower antioxidant status and higher oxidative stress are associated with hypertension, and suggest the need for longitudinal studies to examine causality and intervention studies to determine the benefit of antioxidants in this group.

Maternal intravaginal prostaglandin E2 gel before elective caesarean section at term to induce catecholamine surge in cord blood: randomised, placebo controlled study

OBJECTIVE

To test the hypothesis that the application of intravaginal prostaglandin E(2) gel before elective caesarean section (ECS) will induce a catecholamine surge in umbilical arterial blood.

DESIGN

Randomised, double blind, placebo controlled trial.

SETTING

A regional perinatal referral centre.

PATIENTS

Mothers booked for ECS at or above 38 weeks gestation.

INTERVENTIONS

Thirty six consenting mothers were randomly allocated to receive either 2 mg intravaginal prostaglandin E(2) gel (study group; n = 18) or an equal volume of K-Y jelly as a placebo (control group; n = 18) 60 minutes before the ECS. Computer generated random numbers contained in coded, sealed envelopes were used for allocation. The obstetric and neonatal teams were blinded to the randomisation status of enrolled mothers.

MAIN OUTCOME MEASURES

Catecholamine concentrations in the umbilical arterial blood samples collected at delivery.

RESULTS

The median (interquartile range) neonatal gestation and birth weight were 271 (269-274) days and 3605 (3072-3970) g for the study group and 271 (270-273) days and 3340 (3000-3622) g for the control group. Median (interquartile range) noradrenaline (norepinephrine) concentrations in the umbilical arterial blood were significantly higher in the study group than the control group (15.9 (9.8-28.92) v 4.6 (1.65-14.4) ng/l, p = 0.03). Adrenaline (epinephrine) concentrations did not differ significantly between the two groups (1.6 (< 0.5-3.1) v 1.4 (< 0.5-2.75) ng/l, p = 0.6). No treatment related complications occurred.

CONCLUSION

A labour related catecholamine surge could be simulated by intravaginal prostaglandin E(2) gel.

Modelling and control of potable water chlorination

The Umgeni Water Wiggins water treatment plant feeds the southern areas of Durban in South Africa and has a maximum treatment capacity of about 350 Ml/d. Two interconnected reservoirs at this facility hold treated water before it enters the distribution network. Because of the variable demand, the reservoir levels and residence times undergo considerable variation. This has a strong influence on the free chlorine concentration in the water leaving the reservoir, which should be 0.8 to 1.2 mg/l, to ensure an adequate disinfection potential within the network. This paper describes a model which accounts for the observed variations of chlorine concentration, and will form the basis of a predictive controller for the chlorine concentration in the outlet.

Postnatal changes in maternal and neonatal plasma antioxidant vitamins and the influence of smoking

OBJECTIVE

To study the postnatal changes in the plasma concentrations of fat soluble antioxidant vitamins and malondialdehyde (MDA) in mothers and their newborns and their relation to smoking.

DESIGN

Prospective cohort study.

SETTING

Tertiary perinatal centre.

SUBJECTS

Eighteen non-smoking and 14 smoking mothers and 33 infants.

MAIN OUTCOME MEASURES

Plasma concentrations of vitamins E, A, and beta-carotene and MDA were measured in mothers and infants at delivery and on day 4 post partum.

RESULTS

Neonatal plasma levels of vitamins E, A, and beta-carotene were significantly lower than maternal levels both at delivery and on day 4 in both groups. There was a significant postnatal increase in plasma vitamin E levels in smoking mothers and neonates of both groups. A significant postnatal increase in maternal, but not neonatal, plasma vitamin A was noted in both groups. Cord plasma vitamin E levels were significantly lower in infants of smoking mothers (mean 4.7 v 6.5 micromol/l, p = 0.041). Plasma MDA was paradoxically lower in smoking mothers at delivery (3.19 v 4.01 micromol/l, p = 0.03) and on day 4 (1.37 v 3.29 micromol/l, p = 0.005) and in infants of the smoking group on day 4 (2.18 v 3.12 micromol/l, p = 0.014). Also, there was a significant postnatal fall in plasma MDA levels on day 4 in mothers and infants in the smoking group.

CONCLUSIONS

The postnatal changes in plasma vitamin E were more pronounced in the smoking group. The postnatal changes in plasma vitamins A and beta-carotene were similar in both groups. The rapid decline in plasma MDA in smoking mothers and their infants suggests withdrawal of oxidative stress from smoking around delivery. This coincided with the increase in plasma vitamin E.

A preliminary open label dose comparison using an antioxidant regimen to determine the effect on viral load and oxidative stress in men with HIV/AIDS

OBJECTIVE

To investigate the effect of antioxidant supplementation on viral load and the antioxidant/reactive oxygen species system in people with HIV.

DESIGN

Single centre, prospective, dose comparison study.

SETTING

Outpatient clinic specializing in HIV care.

SUBJECTS

Sixty-six participants were sequentially recruited by advertisement, and 48 subjects completed the study.

INTERVENTIONS

A recommended dose antioxidant regimen (5,450 IU vitamin A as beta-carotene, 250 mg vitamin C, 100 IU vitamin E, 100 microg selenium, 50 mg coenzyme Q10) or a high-dose antioxidant regimen (21,800 IU vitamin A as beta-carotene, 1,000 mg vitamin C, 400 IU vitamin E, 200 microg selenium, 200 mg coenzyme Q10) for a 12 week period.

RESULTS

Using repeated measures analysis of variance, the changes over treatment time were significant for selenium, glutathione, glutathione peroxidase and lipid peroxides (P < 0.03). Changes in allantoin, uric acid and viral load were not significant (P > 0.05). The main effects for group and the interaction effects were not significant for any of the parameters measured (P > or = 0.05).

CONCLUSION

Antioxidant supplementation significantly improved some measures of oxidative defence. There was no benefit in using a high-dose supplement in this study.

Pharmacokinetics of ciprofloxacin in the human eye: a clinical study and population pharmacokinetic analysis

Ciprofloxacin, a fluoroquinolone antibiotic active against a wide variety of bacteria, is one of a few antibiotics which enters the human eye after oral administration. However, little is known about its pharmacokinetics in the human eye. One or two oral doses of 750 mg of ciprofloxacin (at a 12-h interval) were administered to 48 patients at various times prior to ocular surgery. Clotted blood, aqueous, and vitreous were collected at surgery, and the concentrations of ciprofloxacin were assayed by high-performance liquid chromatography. Our data were combined with those of others, and a population pharmacokinetic analysis was conducted. The concentrations of ciprofloxacin in both aqueous and vitreous were lower than those in serum and peaked at a later time. The pharmacokinetics of ciprofloxacin in aqueous and vitreous were fitted to a compartmental model in which the antibiotic was transferred into and out of the two compartments (aqueous and vitreous) by first-order processes. Population pharmacokinetic software, P-Pharm, was used to calculate the mean half-lives of the loss of ciprofloxacin from aqueous and vitreous, which were 3.5 and 5.3 h, respectively. At steady state, the mean ratios of then concentrations in aqueous and vitreous to the concentrations in serum were 23 and 17%, respectively. After the administration of one or two doses of 750 mg of ciprofloxacin, the concentrations in both aqueous and vitreous in a number of patients were lower than the MICs at which 90% of isolates are inhibited (0.5 mg/liter) for common intraocular bacterial pathogens. Simulations of concentrations in the eye after the administration of higher doses (1,500 mg of ciprofloxacin as a single dose, two doses of 750 mg 2 h apart, and 750 mg every 6 h) indicated that in approximately 20% of patients the concentrations would still be below 0.5 mg/liter. Although oral ciprofloxacin may be a beneficial adjunctive therapy, the use of oral ciprofloxacin alone may not be adequate for perioperative prophylaxis or for treatment of bacterial endophthalmitis.

Does alcohol directly stimulate pancreatic fibrogenesis? Studies with rat pancreatic stellate cells

BACKGROUND & AIMS

Activated pancreatic stellate cells have recently been implicated in pancreatic fibrogenesis. This study examined the role of pancreatic stellate cells in alcoholic pancreatic fibrosis by determining whether these cells are activated by ethanol itself and, if so, whether such activation is caused by the metabolism of ethanol to acetaldehyde and/or the generation of oxidant stress within the cells.

METHODS

Cultured rat pancreatic stellate cells were incubated with ethanol or acetaldehyde. Activation was assessed by cell proliferation, alpha-smooth muscle actin expression, and collagen synthesis. Alcohol dehydrogenase (ADH) activity in stellate cells and the influence of the ADH inhibitor 4-methylpyrazole (4MP) on the response of these cells to ethanol was assessed. Malondialdehyde levels were determined as an indicator of lipid peroxidation. The effect of the antioxidant vitamin E on the response of stellate cells to ethanol or acetaldehyde was also examined.

RESULTS

Exposure to ethanol or acetaldehyde led to cell activation and intracellular lipid peroxidation. These changes were prevented by the antioxidant vitamin E. Stellate cells exhibited ethanol-inducible ADH activity. Inhibition of ADH by 4MP prevented ethanol-induced cell activation.

CONCLUSIONS

Pancreatic stellate cells are activated on exposure to ethanol. This effect of ethanol is most likely mediated by its metabolism (via ADH) to acetaldehyde and the generation of oxidant stress within the cells.

Etoposide as a virocidal anticytomegalovirus therapy: intravitreal toxicology and pharmacology in rabbits

BACKGROUND

Although Cytomegalovirus (CMV) retinitis is now a common intraocular infection, current therapy is only virostatic so ongoing treatment is required. Etoposide was found to be virocidal for CMV in laboratory experiments and it might prove to be beneficial clinically. We investigated the toxicity and intraocular concentration of etoposide (VP16) and its new analogue etoposide-phosphate (VP16P) following intravitreal injections in rabbit eyes.

METHODS

First a sequential dose-response was assessed with flash electroretinogram for both eyes of light- and dark-adapted rabbits (n = 7; one rabbit for each dose) over a range of light intensities before and after intravitreal injection of VP16 or VP16P to one eye; the other eye was injected with normal saline as a control. A multidose study was then performed on four rabbits. A non-toxic dose of VP16P (50 or 75 g) was injected into the vitreous of one eye on four occasions 1 week apart. A photopic electroretinogram was performed before the first injection and 6 weeks after the last injection. All the eyes from the electroretinogram studies were fixed in formalin, placed in paraffin, then stained with haematoxylin and eosin and examined under a light microscope. To determine the time-course of the intraocular concentrations of VP16P a sequential pharmacokinetic study was performed using a further 12 rabbits. Each rabbit was injected with 50 g VP16P to one eye and 75 g VP16P to the other eye. Three of these rabbits were killed at 1, 3, 6 and 9 h after injection. Samples of vitreous were assayed for both VP16 and VP16P using HPLC. An in vitro dose response assay was performed using third-passage bovine retinal pigment epithelial (RPE) cells cultured in Dulbecco's modified Eagles medium with fetal calf serum. The effect of a log-dose increment of VP16P on the RPE cell proliferation was assessed using tritiated thymidine incorporation.

RESULTS

The electroretinogram studies suggested that VP16 was toxic even with the 10 g dose. For VP16P a toxic effect was noted following injection of a single dose greater than 100 g. Multiple injections of 50 or 75 g VP16P did not produce a toxic response. Histological examination demonstrated significant abnormality only with the 500 g dose of VP16 or VP16P. VP16P was rapidly metabolized to VP16 in the eye, producing concentrations of 2.0 g/mL or more for up to 9 h following a 75-microg dose. This suggests that the electroretinogram findings following VP16 injections were confounded by a toxic effect of the ethanol solvent (which is absent from the VP16P preparation). VP16P was quite potent, the ID50 was about 0.1 g/mL for bovine RPE cells in the in vitro assay.

DISCUSSION

These results indicate that multiple 75-gVP16P intravitreal injections were not toxic to the rabbit eye and provide a therapeutic intraocular concentration for up to 9 h after the injection.

Elevated creatinine after ingestion of model aviation fuel: interference with the Jaffe reaction by nitromethane

A 2 years 9 month-old-boy who ingested model aviation fuel was found to have an elevated serum creatinine concentration of 0.53 mmol/L (normal range 0.02-0.05 mmol/L) by the Jaffe (alkaline picrate) reaction. However, when the creatinine concentration was measured using a specific enzymatic assay, it was within the normal range. It was shown that nitromethane, a constituent of aviation fuel, interferes with the Jaffe reaction, leading to a falsely elevated creatinine reading. This phenomenon has been reported only once previously and, despite its potential clinical importance, nitromethane does not appear in published lists of substances that interfere with the Jaffe reaction.

Vitamin K in preterm breastmilk with maternal supplementation

Six healthy lactating mothers who gave birth to preterm infants at a median post conceptional age of 29.5 (range 26-30) weeks were given 2.5 mg phylloquinone (vitamin K1) orally daily for 2 weeks beginning at a median postconceptional age of 31.5 (range 28-32) weeks. Phylloquinone was measured in the breastmilk daily for 14 d. Trough plasma phylloquinone concentrations were also determined on four occasions. Phylloquinone levels in the breastmilk increased from a baseline of 3 +/- 2.3 ng ml(-1) to 22.6 +/- 16.3 ng ml(-1) (mean +/- SD) after the first dose (p < 0.05); a gradual increase was noted until phylloquinone levels reached a plateau of 64.2 +/- 31.4 ng ml(-1) after the sixth daily dose.

Failure of iron chelators to reduce tumor growth in human neuroblastoma xenografts

Neuroblastoma (NB) is a high risk tumor of childhood, and raised serum ferritin is an adverse prognostic factor. The hypothesis that iron chelation therapy impacts tumor status and patient prognosis through changes in iron metabolism has been systematically evaluated here in a xenograft model of human NB. One of two iron chelators was given in seven different regimens to nude mice xenografted s.c. with either IMR-32, an established cell line, or JBN-1, heterotransplanted directly from a patient. Nude mice (a total of 160 in 24 cohorts) were given: desferrioxamine (DFO) by s.c. bolus or reservoir; 1,2-dimethyl-3-hydroxypyridin-4-one (L1), i.p. or orally; or saline. Measurements of mean Hb and liver iron levels were compared with corresponding saline cohorts per regimen as well as for pooled cohorts per agent for both cell lines. For IMR-32 xenografts, significant differences in Hb were achieved with L1 (10.9 g/dl pooled versus 13.7 g/dl controls) and in liver iron with DFO and L1 (235 microg/g and 306 microg/g, respectively, versus 520 microg/g). For JBN-1, the pattern was similar. With L1, H6 was 10.2 g/dl and controls were 11.7 g/dl (individual DFO cohorts were also significant); liver iron with DFO was 303 microg/g, liver iron with L1 was 270 microg/g, and controls were 387 microg/g. Additional therapy prior to tumor injection (67 mice and 10 cohorts) did not increase the depletion. Despite documentation of iron depletion, no reductions in tumor engraftment, latency, or tumor size at end point were achieved in the chelator-treated mice, compared with controls populations. Accordingly, inclusion of these iron chelators in clinical trials for NB appears unwarranted.

Effect of high glucose on permeability of retinal capillary endothelium in vitro

PURPOSE

To study the effect of high glucose on the permeability of bovine retinal capillary endothelial cell (BRCEC) monolayers.

METHODS

The paracellular permeability of second-passage BRCEC cultured on millipore filters in two chamber transwell inserts was assayed by measuring the peak trans-monolayer electrical resistance and percent equilibration of 14C-inulin 48 hours after it had been added to the luminal chamber.

RESULTS

High glucose increased the paracellular permeability of BRCEC monolayers independently of its hypertonic action (5 mM glucose: 154.2 +/- 21.2 and 19.5 +/- 2.4; 30 mM glucose: 134.2 +/- 5.1 [P = 0.01] and 23.5 +/- 2.1 [P = 0.01]; 5 mM glucose + 25 mM mannitol: 168.7 +/- 13.7 ohm.cm2 [P = 0.04] and 19.3% +/- 1.2% 48-hour equilibration of inulin [P = 0.008]). In a separate series of experiments, the authors were unable to show that either aminoguanidine or ponalrestat prevented the effect of high glucose on permeability (30 mM glucose 95.1 +/- 16.7 and 45.4 +/- 5.6; 5 mM glucose: 122.9 +/- 14.2 [P = 0.02] and 36.6 +/- 5.6 [P = 0.001]; 30 mM glucose + aminoguanidine 87.9 +/- 17.5 [P = 0.04] and 75.3 +/- 14.9 [P = 0.6]; 30 mM glucose + ponalrestat 79.9 +/- 12.7 ohm.cm2 [P = 0.1] and 48.2 +/- 2.5% 48-hour equilibration of inulin [P = 0.15]). Ponalrestat did not abrogate the effect of high glucose despite its ability to reduce a high glucose-induced increase in BRCEC intracellular sorbitol levels.

CONCLUSIONS

The data are consistent with a role for increased paracellular permeability in breakdown of the blood-retinal barrier in diabetic retinopathy, which appears to be independent of both nonenzymatic glycosylation and the polyol pathway.

Compatibility of propofol, fentanyl, and vecuronium mixtures designed for potential use in anesthesia and patient transport

STUDY OBJECTIVE

To determine whether propofol emulsion, fentanyl, and vecuronium remain compatible and stable when mixed in clinically appropriate concentrations.

DESIGN

Seven separate in vitro experiments. Two different propofol-fentanyl-vecuronium mixtures were formulated. Regular assays of propofol, fentanyl, and vecuronium were performed during a 90-minute infusion period and also during storage of one of the mixtures for 30 days at 4 degrees C, 22 degrees C, and 30 degrees C. Initial and storage pH were determined, and assays of the three drugs were performed when pH of the mixtures was varied between 1.4 and 12.7. Emulsion stability was assessed by measuring immediate and delayed alterations in droplet charge (zeta potential) and size. Finally, samples of the stored mixtures were incubated in culture medium for one week.

SETTING

Teaching hospital and university laboratories.

MEASUREMENTS AND MAIN RESULTS

Concentrations of the three drugs remained unchanged during infusion. During storage, concentrations of all three drugs were stable for two weeks at 4 degrees C or 22 degrees C, and for several days at 30 degrees C. Initial pH of the two mixtures was 5.1 and 5.3, and pH of the stored mixture increased slowly after 8 days. When the pH of mixtures was greater than or equal to 5.6, concentrations of fentanyl and vecuronium were unstable, but the concentration of propofol remained unchanged. Despite a reduction in zeta potential, immediate droplet size was essentially unchanged. No microbial growth was detected in stored mixtures.

CONCLUSION

The propofol, fentanyl, and vecuronium mixtures studied were compatible and stable immediately after mixing. Appropriate in vitro compatibility testing is recommended before clinical evaluation of propofol-opioid or propofol-opioid-muscle relaxant mixtures.

High dose intravitreal ganciclovir injection provides a prolonged therapeutic intraocular concentration

BACKGROUND

Although intravitreal high dose ganciclovir has previously been found to provide excellent control of cytomegalovirus (CMV) retinitis, little was known about the vitreous concentrations of ganciclovir after a 2 mg intravitreal injection.

METHODS

Eleven vitreous samples were taken from seven patients with CMV retinitis at 24 and 72 hours after a 2 mg intravitreal injection of ganciclovir and the concentration of ganciclovir was measured by high performance liquid chromatography.

RESULTS

The mean concentration of ganciclovir at 24 hours was 143.8 mg/l (95% confidence interval 97.8-190) and at 72 hours was 23.4 mg/l (95% CI 0-49.7). The half life ranged from 11.9 to 26.3 (mean 18.8) hours in the four patients who had two samples taken. The mean half life calculated from the mean concentrations at 24 and 72 hours was 18.3 hours, so the calculated mean concentration at 7 days was 0.6 mg/l.

CONCLUSIONS

This suggests that it takes about 7 days to eliminate the intravitreal ganciclovir, and that it is not likely to accumulate with weekly injections. The intravitreal concentrations achieved with high dose therapy remained above the ID50 for CMV (0.25-1.22 mg/l) for up to 7 days.

Different electrophoretic techniques produce conflicting data in the analysis of myocardial samples from dilated cardiomyopathy patients: protein levels do not necessarily reflect mRNA levels

A variety of electrophoretic techniques were used to search for potential causes of human dilated cardiomyopathy (DCM). Northern blots were used to quantify alpha-cardiac and alpha-skeletal muscle actins, and beta-myosin heavy chain mRNAs which are the predominant expressed isoform species. We found a wide range of mRNA levels expressed in both DCM and nondiseased (ND) samples of left ventricles. However, sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) gels of the same heart samples revealed a stable and constant ratio of actin and myosin. Dystrophin deficiency might account for the DCM symptoms and so dystrophin levels of DCM and ND samples were evaluated using Western blots probed with monoclonal antibodies for the N-, C- and mid-rod portions of this protein. We found that dystrophin levels were constant in all 29 DCM and 5 ND samples suggesting that dystrophin deficiency is probably not a contributing cause. We explored the possibility that terminal failure may be due to an apoptotic-like event in the cardiomyocytes. Zymograms of DCM and ND samples revealed a significant increase in DNase I activity in the DCM group compared to the ND samples. These data raise the possibility that end-stage failure may be associated with apoptosis.