The relative efficacy of multiple syringe tip disinfection techniques against virulent staphylococcus contamination

BACKGROUND

A recent study confirmed significant contamination of syringe tips following routine anaesthesia practice of at least 6 h in duration.

AIM

We assessed the relative efficacy of clinically relevant syringe tip disinfection techniques following contamination with the hyper transmissible and more pathogenic Staphylococcus aureus sequence type 5 (S. aureus ST5) strain characteristic associated with increased strength of biofilm formation and greater desiccation tolerance.

METHODS

Syringe tips (N=40) contaminated with S. aureus ST5 were randomized to 70% isopropyl pads with 10 or 60 s of drying time, scrubbing alcohol disinfection caps with 10 or 60 s of dwell time, or to non-scrubbing alcohol disinfection caps with 60 s of dwell time. The primary outcome was residual 24-h colony forming units (cfu) >10.

RESULTS

Scrubbing disinfection caps were more effective than alcohol pads (25% (12/48) <10 cfu for scrubbing caps (10- or 60-s dwell times) vs 0% (0/48) <10 cfu for alcohol pads (10 or 60 s of drying time), Holm-Sidak adjusted P=0.0016). Scrubbing disinfection caps were more effective than non-scrubbing alcohol disinfection caps (25% (12/48) <10 cfu for scrubbing alcohol caps (10- or 60-s dwell times) vs 2% (1/48) for non-scrubbing alcohol caps (60-s dwell time), adjusted P=0.0087).

CONCLUSIONS

Scrubbing alcohol caps are more effective than alcohol pads or non-scrubbing disinfecting caps for microbial reduction of syringe tips contaminated with the more pathogenic S. aureus ST5.

Estimating the birth prevalence and pregnancy outcomes of congenital malformations worldwide

Congenital anomaly registries have two main surveillance aims: firstly to define baseline epidemiology of important congenital anomalies to facilitate programme, policy and resource planning, and secondly to identify clusters of cases and any other epidemiological changes that could give early warning of environmental or infectious hazards. However, setting up a sustainable registry and surveillance system is resource-intensive requiring national infrastructure for recording all cases and diagnostic facilities to identify those malformations that that are not externally visible. Consequently, not all countries have yet established robust surveillance systems. For these countries, methods are needed to generate estimates of prevalence of these disorders which can act as a starting point for assessing disease burden and service implications. Here, we describe how registry data from high-income settings can be used for generating reference rates that can be used as provisional estimates for countries with little or no observational data on non-syndromic congenital malformations.

Anti-methicillin-resistant Staphylococcus aureus (MRSA) activity of Rubiaceae, Fabaceae and Poaceae plants: A search for new sources of useful alternative antibacterials against MRSA infections

In this study, we evaluated the effects of the extracts of the leaves of species from the Rubiaceae (Galium aparine L. and Asperula arvensis L.), Fabaceae (Lathyrus aphaca L. and Vicia narbonensis L.) and Poaceae (Digitaria sanguinalis (L.) Scop. and Hordeum murinum L.) plant families on a wide and extensive panel of isolated methicillin-resistant Staphylococcus aureus strains (MRSA). The effects of the methanolic leaf extracts of Rubiaceae, Fabaceae and Poaceae plants on MRSA were evaluated by the disc diffusion assay and the broth dilution method. Among a total of 177 S. aureus isolates, 92 (51.97%) were found to be methicillin-resistant in an antibiogram and this was confirmed by the presence of the mecA gene in polymerase chain reaction method. All MRSA isolates were sensitive to all extracts. There were dose-dependent inhibitions on tested microorganisms for all plant extracts which showed maximum inhibition zones at a concentration of 300 mg/L. L. aphaca, G. aparine and H. murinum exhibited the highest antibacterial activity on the MRSA strains compared to the positive control (P < 0.05), as well as higher total polyphenol and flavonoid contents than other plant extracts. Minimum inhibitory concentrations on MRSA isolates ranged from 388.4 ± 0.2 mg/L, in D. sanguinalis, to 5.5 ± 0.1 mg/L, in L. aphaca. The methanolic extracts of L. aphaca (Fabaceae), G. aparine (Rubiaceae), and H. murinum (Poaceae) proved to have high antibacterial activity on MRSA isolates, thus representing promising antimicrobial agents in clinical settings.

Utility of therapeutic drug monitoring in the management of HIV-infected pregnant women in receipt of lopinavir

The pharmacokinetics of antiretroviral drugs in pregnancy is poorly understood. We reviewed the use of therapeutic drug monitoring (TDM) in clinical settings to document plasma concentrations of lopinavir during pregnancy and investigated how clinicians acted upon TDM results. A retrospective review was carried out of all HIV-infected pregnant women taking boosted lopinavir-based highly active antiretroviral therapy (HAART) at five National Health Service (NHS) centres in the UK between May 2004 and March 2007. Seventy-three women in receipt of lopinavir were identified, of whom 89% had plasma lopinavir concentrations above the suggested minimum recommended for wild-type HIV. Initial TDM results prompted dosage change in 10% and assessment of adherence and/or pharmacist review in 11%. TDM was repeated in 29%. TDM can play an important role in the clinical management of HIV-positive pregnant women, allowing informed dose modification and an alternative measure of adherence.

Antitumour antibiotics with potent activity against multidrug resistant (MDR) Staphylococcus aureus: a new approach to targeting resistant bacteria

As hospital reports of strains of resistant bacteria are continuing to increase, a new approach is required for the identification of small molecules with antibacterial activity. Natural products that bind covalently to their biological target have been largely unexplored, although in the field of cancer chemotherapy, such molecules have been shown to counter resistance developed through efflux mechanisms. The azinomycins are potent antitumour agents that alkylate DNA and one of the natural products, compound 1, is a mono-alkylator that has been reported to retain potent antitumour activity. All four diastereomers of 1 were synthesized via a route involving late stage introduction of the epoxide stereocentre and separation of the resulting compounds. A non-alkylating analogue and a potential alkylator that cannot intercalate were also made. All four diastereomers are potent antibacterial agents in cell lines containing efflux-based resistance mechanisms. MIC values in the range of 0.25-1.0 microg/ml were observed. Comparison with the antitumour activity of the compounds suggests that the antibacterial activity stems from a similar mechanism of action involving DNA alkylation. As the ultimate molecular target of the azinomycins is unknown, bacterial strains may represent an interesting route for the discovery of the downstream mechanisms affected by DNA alkylation.

Knipholone, a selective inhibitor of leukotriene metabolism

Inhibition of leukotriene formation is one of the approaches to the treatment of asthma and other inflammatory diseases. We have investigated knipholone, isolated from the roots of Kniphofia foliosa, Hochst (Asphodelaceae), for inhibition of leukotriene biosynthesis in an ex vivo bioassay using activated human neutrophile granulocytes. Moreover, activities on 12-lipoxygenase from human platelets and cycloxygenase (COX)-1 and -2 from sheep cotyledons and seminal vesicles, respectively, have been evaluated. Knipholone was found to be a selective inhibitor of leukotriene metabolism in a human blood assay with an IC(50) value of 4.2microM. However, at a concentration of 10microg/ml, the compound showed weak inhibition of 12(S)-HETE production in human platelets and at a concentration of 50microM it produced no inhibition of COX-1 and -2. In our attempt to explain the mechanism of inhibition, we examined the antioxidant activity of knipholone using various in vitro assay systems including free radical scavenging, non-enzymatic lipid peroxidation, and metal chelation. Knipholone was found to be a weak dose-independent free radical scavenger and lipid peroxidation inhibitor, but not a metal chelator. Therefore, the leukotriene biosynthesis inhibitory effect of knipholone was evident by its ability either to inhibit the 5-lipoxygenase activating protein (FLAP) or as a competitive (non-redox) inhibitor of the enzyme. Cytotoxicity results also provided evidence that knipholone exhibits less toxicity for a mammalian host cell.

Antimicrobial, resistance-modifying effects, antioxidant and free radical scavenging activities ofMezoneuron benthamianum Baill.,Securinega virosa Roxb. &Wlld. andMicroglossa pyrifolia Lam

Mezoneuron benthamianum, Securinega virosa and Microglossa pyrifolia are used in folk medicine in Ghana for the treatment of dermal infections and wounds. Petroleum spirit, chloroform and ethanol extracts of the plants were tested for antimicrobial activity against a battery of organisms using the agar well diffusion technique and a serial dilution microassay. The resistance modifying activities of these extracts on standard antibiotics against Staphylococcus aureus possessing efflux mechanisms of resistance have also been assessed. A 4-fold potentiation of the activity of norfloxacin was observed for ethanol and chloroform extracts of M. benthamianum and S. virosa, respectively, whilst the petroleum spirit extract resulted in a 2-fold potentiation with minimum inhibitory concentration (MIC) values in the range 8-16 microg/mL. Ethanol extracts of all three species, the petroleum spirit extract of M. benthamianum and the chloroform extracts of M. benthamianum and S. virosa, showed interesting antimicrobial activities. Antioxidant and free radical scavenging activities using DPPH spectrophotometric and TBA lipid peroxidation assays were also conducted. Of the five extracts that showed antioxidant activities, the petroleum spirit and chloroform extracts of M. benthamianum rated most highly by displaying strong free radical scavenging activity with IC50 values of 15.33 and 19.72 microg/mL, respectively. Lipid peroxidation inhibition provided by the same two extracts also produced the lowest IC50 values for all the extracts tested, of 23.15 and 30.36 microg/mL. These findings therefore give some support to the ethnopharmacological use of the plants in the treatment of various skin diseases and wounds, as well as demonstrating the potential of some of the plants as sources of compounds possessing the ability to modulate bacterial multidrug resistance.

Anti-inflammatory activity of extracts and a saponin isolated from Melilotus elegans

The crude methanol extract of Melilotus elegans Ser. (Fabaceae), a plant widely used in Ethiopian traditional medicine for the treatment of asthma, haemorrhoid and lacerated wounds showed a significant anti-inflammatory activity against carrageenin-induced rat paw oedema. At a dose corresponding to 333.3 mg per kg body weight of dry plant material, the methanol extract displayed a strong inhibitory effect that was comparable to the inhibitory effect of 1 mg/kg of indomethacin in the same test system. Bioassay guided fractionation of the alcoholic extract led to the isolation of an oleanene-type triterpene saponin identified as azukisaponin V (1) ((3-O-[alpha-L-rhamnopyranosyl-(1 --> 2)-beta-D-glucopyranosyl(1 --> 2)-beta-D-glucuronopyranosyl]-soyasapogenol B). The structure of the compound was identified by using MS and extensive one- and two-dimensional NMR experiments (1H, 13C, COSY, HMQC, HMBC and NOESY). One hour after injection of carrageenin, inhibition of oedema exerted by 1 was approximately ten times higher than that of indomethacin on a molar basis.

Medicinal cannabis: is delta9-tetrahydrocannabinol necessary for all its effects?

Cannabis is under clinical investigation to assess its potential for medicinal use, but the question arises as to whether there is any advantage in using cannabis extracts compared with isolated Delta9-trans-tetrahydrocannabinol (Delta9THC), the major psychoactive component. We have compared the effect of a standardized cannabis extract (SCE) with pure Delta9THC, at matched concentrations of Delta9THC, and also with a Delta9THC-free extract (Delta9THC-free SCE), using two cannabinoid-sensitive models, a mouse model of multiple sclerosis (MS), and an in-vitro rat brain slice model of epilepsy. Whilst SCE inhibited spasticity in the mouse model of MS to a comparable level, it caused a more rapid onset of muscle relaxation, and a reduction in the time to maximum effect compared with Delta9THC alone. The Delta9THC-free extract or cannabidiol (CBD) caused no inhibition of spasticity. However, in the in-vitro epilepsy model, in which sustained epileptiform seizures were induced by the muscarinic receptor agonist oxotremorine-M in immature rat piriform cortical brain slices, SCE was a more potent and again more rapidly-acting anticonvulsant than isolated Delta9THC, but in this model, the Delta9THC-free extract also exhibited anticonvulsant activity. Cannabidiol did not inhibit seizures, nor did it modulate the activity of Delta9THC in this model. Therefore, as far as some actions of cannabis were concerned (e.g. antispasticity), Delta9THC was the active constituent, which might be modified by the presence of other components. However, for other effects (e.g. anticonvulsant properties) Delta9THC, although active, might not be necessary for the observed effect. Above all, these results demonstrated that not all of the therapeutic actions of cannabis herb might be due to the Delta9THC content.

Intra-alveolar distraction osteogenesis in preparation for dental implant placement combined with orthodontic/orthognathic surgical treatment: A case report

The use of implants has become a routine part of restorative dental treatment. The placement of implants requires a sufficient quantity of bone in which to place implant fixtures. Where such bone does not exist, a number of methods have been used to augment the affected area of the alveolar ridge. This case report describes the use of the relatively new distraction osteogenesis procedure to increase bone volume in a patient who required post-traumatic restoration of several missing teeth, as well as comprehensive orthodontic and orthognathic surgical treatment.

Src homology 2 domain-containing inositol 5' phosphatase is negatively associated with histamine release to human recombinant histamine-releasing factor in human basophils

BACKGROUND

The human recombinant histamine-releasing factor (HrHRF) acts as a complete stimulus for histamine release and IL-4 secretion from a subpopulation of highly allergic donor basophils, termed IgE(+) basophils. Additionally, IgE(+) basophils release histamine to other secretogues, IL-3, and deuterium oxide. We hypothesized that IgE(+) basophils were hyperreleasable.

OBJECTIVE

Deficiencies in early signal transduction events associated with Fc(epsilon)RI lead to a nonreleasable phenotype, whereas the Src homology 2 domain--containing inositol 5' phosphatase (SHIP) knockout mice have hyperreleasable mast cells. The purpose of this study was to ascertain whether a difference in intracellular signaling molecules could explain the hyperreleasable phenotype of human IgE(+) basophils.

METHODS

Basophils were purified by means of double Percoll gradients and negative selection with magnetic beads. Cell lysates were Western blotted for the tyrosine kinases Lyn and Syk and the phosphatase SHIP. Additionally, histamine release to HrHRF was performed in addition to real-time RT-PCR to investigate mRNA for SHIP.

RESULTS

We show a striking negative correlation between the amount of SHIP protein per cell equivalent, but not Lyn or Syk, and maximum histamine release to HrHRF. This deficiency of SHIP was observed in basophils, but not lymphocytes or monocytes, of these IgE(+) donors. Additionally, levels of mRNA for SHIP did not differ between IgE(+) and IgE(-) donor basophils, which is consistent with a posttranscriptional mechanism of protein regulation. SHIP and phosphatidylinositol 3-kinase reciprocally regulate phosphatidylinositol (3,4,5) triphosphate levels. We also demonstrated that Ly294002, the phosphatidylinositol 3 kinase inhibitor, prevented HrHRF-induced histamine release in IgE(+) donor basophils.

CONCLUSION

Taken together, these data suggest that the hyperreleasability of IgE(+) donors is associated with low levels of SHIP and implicate SHIP as an additional regulator of secretion in human basophils.

Antihypertensive effect of an aqueous extract of Zygophyllum coccineum L. in rats

The effects of an aqueous extract of Zygophyllum coccineum L. on rat blood pressure (BP) and on the mesenteric vascular bed were investigated. The extract dose-dependently reduced BP and heart rate in normotensive and spontaneously hypertensive rats (SHRs). It also reduced BP in pithed SHRs. In vitro, the extract had no effect on basal perfusion pressure of the mesenteric vascular bed. When the perfusion pressure was raised with noradrenaline or potassium chloride, the extract produced a dose-dependent reduction in perfusion pressure. However, in preparations in which the perfusion pressure was raised with KCl, the depressor response to lower doses of the extract was abolished while higher doses produced responses that were reduced in magnitude when compared with similar responses in preparations in which the perfusion pressure was raised with noradrenaline. It was concluded that extracts of Z. coccineum possess significant antihypertensive activity that may involve some membrane hyperpolarization.

Ethnopharmacology in drug discovery: an analysis of its role and potential contribution

In this paper we discuss some examples of ethnopharmacological research as it has been conducted during the last two centuries and look at the current role of this discipline in drug discovery (especially with respect to the American and European markets) and the further development of these phytotherapeutical resources for local use in the countries of origin (ethnopharmacology). Examples from 19th century research on curare (Humboldt and Bernard), from the 20th century on hallucinogenic mushrooms (Wasson), on Mexican Indian indigenous plants (our own research) and of current industry based research are used to illustrate the development of this discipline and to highlight the challenges for the future.

Enoximone pharmacokinetics in infants

Enoximone and enoximone sulphoxide concentrations were measured in plasma of 20 infants, median age 6.0 (range 0.6-49.7) weeks, during and after prolonged continuous infusions. Patients were given enoximone 1 mg kg-1 and an infusion at 10 micrograms kg-1 min-1 just before being weaned from cardiopulmonary bypass (CPB). The infusion was stopped when clinically indicated, after a median 97 (range 24-572) h. Arterial blood samples were taken 30 min and 12 h after CPB, every 24 h during the infusion, and then 2, 4, 8, 12 and 24 h after the infusion was stopped. Pharmacokinetic non-compartmental analysis was performed using TOPFIT software. Fourteen patients who retained normal hepatic function had a median (95% confidence intervals) clearance of 9.7 (6.3-14.1) ml min-1 kg-1, elimination half-life of 5.2 (2.4-6.8) h and a volume of distribution of 3.6 (2.0-5.7) litre kg-1. The six patients with significant hepatic dysfunction had a lower clearance, 5.7 (2.4-14.5) ml min-1 kg-1, and significantly longer elimination half-life, 7.6 (6.5-10.9) h (P = 0.02). Enoximone sulphoxide elimination half-life was significantly prolonged in three patients with renal dysfunction, 16.2 (10.5-17.7) h versus 6.9 (6.1-9.4) h (P = 0.03). These results confirm that enoximone pharmacokinetics in infants is similar to that found in adults. The infusion rate of enoximone should be reduced if hepatic or renal dysfunction supervenes.

NMR spectroscopy, X-ray crystallographic, and molecular modeling studies on a new pyranone from Haloxylon salicornicum

A new pyranone, 5-hydroxy-3-methoxy-4H-pyran-4-one (1), was isolated from the aerial parts of the desert shrub Haloxylon salicornicum. The structure was elucidated by X-ray structural analysis, NMR spectroscopy, and mass spectrometry. The monoacetate was also prepared, and molecular modeling studies and full NMR data were recorded.

The effect of reserpine, a modulator of multidrug efflux pumps, on the in vitro activity of tetracycline against clinical isolates of methicillin resistant Staphylococcus aureus (MRSA) possessing the tet(K) determinant

As part of a screening programme to identify modulators of multidrug efflux in methicillin resistant Staphyloccocus aureus (MRSA), we have validated our assays using the antihypertensive plant alkaloid reserpine. Clinical isolates of MRSA were resistant to tetracycline and shown to possess the tet(K) determinant which encodes for the Tet(K) efflux protein, which conferred high level resistance to tetracycline (MIC = 128 microg/mL). In the presence of reserpine, a known inhibitor of multidrug resistance (mdr) efflux pumps, this MIC was significantly reduced (MIC = 32 microg/mL).

Pharmacokinetics and potential interactions amongst antiretroviral agents used to treat patients with HIV infection

There are 3 groups of drugs available for the treatment of patients with HIV disease. These are the nucleoside reverse transcriptase inhibitors ('nucleoside analogues') [zidovudine, didanosine, zalcitabine, lamivudine and abacavir]; the non-nucleoside reverse transcriptase inhibitors (nevirapine, delavirdine and efavirenz); and the protease inhibitors (saquinavir, ritonavir, indinavir, nelfinavir and amprenavir). The preferred initial regimen should reduce and maintain plasma HIV RNA below the level of detection. Presently, the regimen of choice consists of 2 nucleoside analogues plus a protease inhibitor with high in vivo efficacy. An alternative combination consists of 2 nucleoside analogues plus a non-nucleoside reverse transcriptase inhibitor. Drug interactions are one of the major problems associated with these multidrug regimens. Changes in plasma concentrations of the nucleoside analogues are unlikely to be of clinical relevance as drug effect is mainly dependent on the rate and extent of intracellular phosphorylation. Combinations of zidovudine plus stavudine, and probably zalcitabine plus lamivudine, should be avoided as competition for phosphorylating enzymes may occur. The antiviral efficacy of some nucleoside analogues, e.g. stavudine, may be compromised by prior treatment with other nucleosides (e.g. zidovudine). However, these data need to be clarified in further studies. It is unlikely that administration of other antiretrovirals will influence the activity of nucleoside analogues. Protease inhibitors are metabolised by hepatic cytochrome P450 (CYP) 3A4. Combination protease inhibitor therapy can result in drug interactions mediated by enzyme inhibition. Ritonavir is the most potent inhibitor, saquinavir the least. The protease inhibitors also interact with the non-nucleoside reverse transcriptase inhibitors. Nevirapine and efavirenz induce drug metabolising enzymes and may reduce plasma concentrations of protease inhibitors. A study in healthy volunteers showed that nelfinavir concentrations are increased by combination with efavirenz. Delavirdine inhibits drug metabolising enzymes and increases the plasma concentration of coadministered protease inhibitors. The nucleoside analogues would not be expected to interact with the protease inhibitors. Apart from the ability of didanosine to reduce the area under the concentration-time curve of delavirdine, there are no reports of clinically significant interactions of other antiretrovirals with the non-nucleoside reverse transcriptase inhibitors. Triple therapy is the current standard of care for patients with HIV disease. However, studies of quadruple therapy are already under way. Drug interactions are likely to remain one of the major considerations when selecting a therapeutic regimen for patients with HIV.

Extended field radiation and cisplatin for stage IIB and IIIB cervical carcinoma

OBJECTIVE

The aim of this study was to investigate local regional control, survival, and morbidity in patients with FIGO IIB and IIIB squamous cell carcinoma of the cervix treated with primary extended field (prophylactic paraaoratic radiation) radiation and weekly cisplatin.

METHODS

Sixty-seven patients (44 IIB and 23 IIIB) with carcinoma of the cervix received cisplatin at 1 mg/kg (up to 60 mg) weekly and extended field radiation therapy including the paraaortic nodes and brachytherapy.

RESULTS

After the scheduled therapy 94.1% of the patients were complete responders. Seventy-five percent are alive without evidence of disease with a mean follow-up of 47.5 months.

CONCLUSION

This study confirms the ability to give concomitant weekly cisplatin and prophylactic paraaortic radiation with minimal morbidity. The encouraging Kaplan-Meier survival of 75% and only eight pelvic failures warrants further investigation.

Audit of prenatal diagnosis for haemoglobin disorders in the United Kingdom: the first 20 years

OBJECTIVES

To audit services for prenatal diagnosis for haemoglobin disorders in the United Kingdom.

DESIGN

Comparison of the annual number of cases recorded in a United Kingdom register of prenatal diagnoses for haemoglobin disorders, with the annual number of pregnancies at risk of these disorders, by ethnic group and regional health authority. The number of pregnancies at risk was estimated using data on ethnic group from the 1991 census and data from the United Kingdom thalassaemia register, which records the number of babies born with thalassaemia.

SETTING

The three national prenatal diagnosis centres for haemoglobin disorders.

SUBJECTS

2068 cases of prenatal diagnosis for haemoglobin disorders in the United Kingdom from 1974 to 1994.

MAIN OUTCOME MEASURES

Utilisation of prenatal diagnosis by risk, ethnic group, and regional health authority. Proportion of referrals in the first trimester and before the birth of any affected child.

RESULTS

National utilisation of prenatal diagnosis for haemoglobin disorders was around 20%. During the past 10 years it has remained steady at about 50% for thalassaemias and risen from 7% to 13% for sickle cell disorders. Utilisation for sickle cell disorders varies regionally from 2% to 20%. Utilisation for thalassaemias varies by ethnic group. It is almost 90% for Cypriots and ranges regionally for British Pakistanis from 0% to over 60%. About 60% of first prenatal diagnoses are done for couples without an affected child. Less than 50% of first referrals are in the first trimester.

CONCLUSIONS

National utilisation of prenatal diagnosis for haemoglobin disorders is far lower than expected, and there are wide regional variations. A high proportion of referrals are still in the second trimester and after the birth of an affected child. The findings point to serious shortcomings in present antenatal screening practice and in local screening policies and to inadequate counselling resources, especially for British Pakistanis.

Protease inhibitors in patients with HIV disease. Clinically important pharmacokinetic considerations

Since its introduction in 1987, zidovudine monotherapy has been the treatment of choice for patients with HIV infection. Unfortunately it has been established that the beneficial effects of zidovudine are not sustained due to the development of resistant viral strains. This has led to the strategy of combination therapy, and in 1995 treatment with zidovudine plus didanosine, or zidovudine plus zalcitabine, was demonstrated to be more effective than zidovudine monotherapy in preventing disease progression and reducing mortality in patients with HIV disease. Recent work demonstrates an even greater antiviral effect from triple therapy with 2 nucleosides, zidovudine plus zalcitabine with the addition of saquinavir, a new protease inhibitor drug. The HIV protease enzyme is responsible for the post-translational processing of gag and gag-pol polyprotein precursors, and its inhibition by drugs such as saquinavir, ritonavir, indinavir and VX-478 results in the production of non-infectious virions. As resistance may also develop to the protease inhibitors they may be used in combination, and future strategies may well include quadruple therapy with 2 nucleoside analogues plus 2 protease inhibitors. Administration of protease inhibitors alone or in combination with other drugs does raise a number of important pharmacokinetic issues for patients with HIV disease. Some protease inhibitors (e.g. saquinavir) have kinetic profiles characterised by reduced absorption and a high first pass effect, resulting in poor bioavailability which may be improved by administrating with food. Physiological factors including achlorhydria, malabsorption and hepatic dysfunction may influence the bioavailability of protease inhibitors in HIV disease. Protease inhibitors are very highly bound to plasma proteins (> 98%), predominantly to alpha 1-acid glycoprotein. This may influence their antiviral activity in vitro and may also predispose to plasma protein displacement interactions. Such interactions are usually only of clinical relevance if the metabolism of the displaced drug is also inhibited. This is precisely the situation likely to pertain to the protease inhibitors, as ritonavir may displace other protease inhibitor drugs, such as saquinavir, from plasma proteins and inhibit their metabolism. Protease inhibitors are extensively metabolised by the cytochrome P450 (CYP) enzymes present in the liver and small intestine. In vitro studies suggest that the most influential CYP isoenzyme involved in the metabolism of the protease inhibitors is CYP3A, with the isoforms CYP2C9 and CYP2D6 also contributing. Ritonavir has an elimination half-life (t1/2 beta) of 3 hours, indinavir 2 hours and saquinavir between 7 and 12 hours. Renal elimination is not significant, with less than 5% of ritonavir and saquinavir excreted in the unchanged form. As patients with HIV disease are likely to be taking multiple prolonged drug regimens this may lead to drug interactions as a result of enzyme induction or inhibition. Recognised enzyme inducers of CYP3A, which are likely to be prescribed for patients with HIV disease, include rifampicin (rifampin) [treatment of pulmonary tuberculosis], rifabutin (treatment and prophylaxis of Mycobacterium avium complex), phenobarbital (phenobarbitone), phenytoin and carbamazepine (treatment of seizures secondary to cerebral toxoplasmosis or cerebral lymphoma). These drugs may reduce the plasma concentrations of the protease inhibitors and reduce their antiviral efficacy. If coadministered drugs are substrates for a common CYP enzyme, the elimination of one or both drugs may be impaired. Drugs which are metabolised by CYP3A and are likely to be used in the treatment of patients with HIV disease include the azole antifungals, macrolide antibiotics and dapsone; therefore, protease inhibitors may interact with these drugs. (ABSTRACT TRUNCATED)

Surgical treatment and postoperative splinting of recessive dystrophic epidermolysis bullosa

Digital contractures and pseudosyndactyly, common manifestations in recessive dystrophic epidermolysis bullosa, cause significant functional impairment. The deformities progress with time, although surgery may delay the progression. The role of surgical intervention, hand therapy, and the use of prolonged splinting was examined in seven children (nine hands) with recessive dystrophic epidermolysis bullosa with an average age of 5 years, 8 months (range, 1 year, 10 months to 16 years, 4 months). The technique of surgery, postoperative regimen, and splinting differ from those previously reported. Surgery includes "de-cocooning" the hand and fingers, manipulating contracted joints, and full-thickness skin grafting to dermal defects. Surgery and the postoperative regimen of rigid night splints and web-retaining gloves for day wear has allowed arrest or minimal progression of contractures in complaint patients in short-term follow-up study of an average of 17 months (range, 12-28 months). An interdisciplinary team of physicians and surgeons, therapists, and nurses makes this care regimen possible and influences family compliance.

Fibrinogen Lincoln: a new truncated alpha chain variant with delayed clotting

A patient referred for preoperative investigation of prolonged bleeding and easy bruising was found to have increased thrombin and reptilase times; however, the thrombin catalysed release of fibrinopeptides A and B was normal. Analysis of five other family members, spanning three generations, indicated that three had a similar defect and suggested autosomal dominant inheritance. Non-reducing SDS-PAGE of purified fibrinogen from affected individuals showed that the 340 kD form of their fibrinogen ran as a doublet. SSCP (single-stranded conformational polymorphism) analysis of exon 5 of the A alpha gene, which encodes the C-terminal half of the chain, confirmed the presence of a mutation. Cycle sequencing of PCR amplified DNA revealed a 13 base pair deletion (nt 4758-4770), resulting in a frame-shift at Ala 475, which translates as four new amino acids before terminating at a new stop codon (-476His-Cys-Leu-Ala-Stop). The presence of a circulating truncated A alpha chain was confirmed when SDS-PAGE gels were probed with an alpha chain specific antisera; which showed that the variant A alpha chain comigrated with gamma chains. The truncation results in a variant A alpha chain with a deletion of 131 amino acids (480-610), and four new amino acids at the C-terminal.

Antimicrobial sesquiterpenes from Prostanthera aff. melissifolia and P. rotundifolia

Aerial material of Prostanthera aff. melissifolia and P. rotundifolia yielded three sesquiterpenes, two known compounds and a novel sesquiterpene, prostantherol. Prostantherol was identified as (rel)-1a alpha,3a beta,7a alpha,7b alpha-decahydro-4 beta-hydroxy- 1,1,4 alpha,7 alpha-tetramethylcyclopropa[a]-naphthalene on the basis of a comprehensive spectroscopic analysis. All three compounds were investigated for antimicrobial activity against phytopathogens.

Premature termination codons in the type VII collagen gene (COL7A1) underlie severe, mutilating recessive dystrophic epidermolysis bullosa

Epidermolysis bullosa (EB) is a group of heritable mechano-bullous skin diseases classified into three major categories on the basis of the level of tissue separation within the dermal-epidermal basement membrane zone. The most severe, dystrophic (scarring) forms of EB demonstrate blister formation below the cutaneous basement membrane at the level of the anchoring fibrils. Ultrastructural observations of altered anchoring fibrils and genetic linkage to the gene encoding type VII collagen (COL7A1), the major component of anchoring fibrils, have implicated COL7A1 as the candidate gene in the dystrophic forms of EB. We have recently cloned the entire cDNA and gene for human COL7A1, which has been mapped to 3p21. In this study, we describe mutations in four COL7A1 alleles in three patients with severe, mutilating recessive dystrophic EB (Hallopeau-Siemens type, HS-RDEB). Each of these mutations resulted in a premature termination codon (PTC) in the amino-terminal portion of COL7A1. One of the patients was a compound heterozygote for two different mutations. The heterozygous carriers showed an approximately 50% reduction in anchoring fibrils, yet were clinically unaffected. Premature termination codons in both alleles of COL7A1 may thus be a major underlying cause of the severe, recessive dystrophic forms of EB.

A strategy for supply cost savings

A collaborative team effort and a new software program helped this hospital lab to come in $47,500 under budget on supply expenses.

15 AU81, a prostacyclin analog, potentiates immunosuppression and mitigates renal injury due to cyclosporine

15 AU81, a synthetic prostacyclin analog, inhibits human mixed lymphocyte culture responses in a dose-dependent manner at concentrations within a range [0.1 to 10.0 micrograms/ml] similar to that of cyclosporine, methylprednisolone, antilymphocyte serum, and prostaglandin E1 and E2 analogs. Using the median-effect analysis to dissect immunosuppressive interactions, 15 AU81 and cyclosporine were shown to produce synergistic effects on human peripheral blood lymphocyte activation upon phytohemagglutinin or anti-CD3 monoclonal antibody stimulation. In vivo, 15 AU81 potentiated the effect of cyclosporine to prolong the survival of rabbit renal allografts using concentrations of each agent that were individually ineffective. Furthermore, addition of 15 AU81 mitigated functional damage of rabbit kidneys due to high-dose cyclosporine therapy. These observations suggest that the addition of 15 AU81 may broaden the therapeutic window of cyclosporine by potentiating immunosuppression and mitigating nephrotoxic effects.

Adjuvant whole abdominopelvic irradiation for high risk endometrial carcinoma

Fifty-six patients with surgical Stage III or IV endometrial carcinoma, or earlier stage disease with two or more risk factors for peritoneal recurrence, were given postoperative whole abdomino-pelvic irradiation (WAPI) with nodal and vaginal boosts between November 1981 and May 1989. Mean age at diagnosis was 63 years. Twenty-seven patients were surgical Stage I-II, 17 Stage III, and 12 Stage IV. Thirty-seven (66%) had deep myometrial involvement, 34 (61%) had positive peritoneal cytology, 31 (55%) had high grade lesions, 20 (36%) had either serous-papillary or adenosquamous histologic variants, and 13 (23%) had up to 2 cm residual disease remaining after surgery. Mean overall follow-up was 45 months. The 7-year actuarial survival was 63.8% with a 7-year disease-free survival (DFS) of 60.9%. By surgical stage, the 7-year DSF was 77.1% for Stage I-II, 57.8% for Stage III, and 25.0% for Stage IV (p = 0.006). The 7-year DSF was 79.8% for those with lesions of Broder's grade 1 or 2, and 46.9% for grades 3 or 4 (p = 0.001). Multivariate analysis demonstrated that of all covariates considered, only surgical stage and histologic grade had prognostic significance for survival and disease-free survival. Acute toxicity has been common but mild; chronic toxicity has been almost entirely subclinical with the exception of three cases of moderate to severe bowel toxicity. These results suggest that post-operative WAPI is a safe and efficacious treatment alternative for patients with surgical Stage I through III high-risk endometrial carcinoma.

Survival after resection of carcinoma of the splenic flexure

Nine hundred ten patients undergoing colectomy for colon cancer were studied retrospectively. Seventy-four cancers (8 percent) were located at the splenic flexure. The stage at presentation was no different between splenic flexure cancers and colon carcinomas at other sites. Although splenic flexure cancers had twice the incidence of obstruction as did other colon cancers and obstruction in the overall series adversely affected survival, there was no difference in survival between splenic flexure cancer patients and patients with other colon cancers.