Advanced crystallisation methods for small organic molecules

Molecular materials based on small organic molecules often require advanced structural analysis, beyond the capability of spectroscopic techniques, to fully characterise them. In such cases, diffraction methods such as single crystal X-ray diffraction (SCXRD), are one of the most powerful tools available to researchers, providing molecular and structural elucidation at atomic level resolution, including absolute stereochemistry. However SCXRD, and related diffraction methods, are heavily dependent on the availability of suitable, high-quality crystals, thus crystallisation often becomes the major bottleneck in preparing samples. Following a summary of classical methods for the crystallisation of small organic molecules, this review will focus on a number of recently developed advanced methods for crystalline material sample preparation for SCXRD. This review will cover two main areas of modern small organic molecule crystallisation, namely the inclusion of molecules within host complexes (e.g., "crystalline sponge" and tetraaryladamantane based inclusion chaperones) and the use of high-throughput crystallisation, employing "under-oil" approaches (e.g., microbatch under-oil and ENaCt). Representative examples have been included for each technique, together with a discussion of their relative advantages and limitations to aid the reader in selecting the most appropriate technique to overcome a specific analytical challenge.

Chemical and structural data of (1,2,3-triazol-4-yl)pyridine-containing coordination compounds

The data presented in this paper are related to the research article entitled “Novel dichloro(bis{2-[1-(4-methylphenyl)-1H-1,2,3-triazol-4-yl-κN³]pyridine-κN})metal(II) coordination compounds of seven transition metals (Mn, Fe, Co, Ni, Cu, Zn and Cd)” (Conradie et al., 2018) [1]. This paper presents characterization and structural data of the 2-(1-(4-methyl-phenyl)-1H-1,2,3-triazol-1-yl)pyridine ligand (L²) (Tawfiq et al., 2014) [2] as well as seven dichloro(bis{2-[1-(4-methylphenyl)-1H-1,2,3-triazol-4-yl-κN³]pyridine-κN})metal(II) coordination compounds, [M(L²)₂Cl₂], all containing the same ligand but coordinated to different metal ions. The data illustrate the shift in IR, UV/VIS, and NMR (for diamagnetic complexes) peaks when L is coordinated to the metals, as well as the influence of the different metals on the peak positions. Solid state structural data is presented for M = Ni and Zn, while density functional theory calculated energies, structures and optimized coordinates are provided for the lowest energy cis and trans conformations for L² as well as [M(L²)₂Cl₂] with M = Mn, Fe, Co, Ni, Cu, Zn and Cd.

[MIII2MII3] n+ trigonal bipyramidal cages based on diamagnetic and paramagnetic metalloligands

A family of five [MIII2MII3] n+ trigonal bipyramidal cages (MIII = Fe, Cr and Al; MII = Co, Zn and Pd; n = 0 for 1-3 and n = 6 for 4-5) of formulae [Fe2Co3L6Cl6] (1), [Fe2Zn3L6Br6] (2), [Cr2Zn3L6Br6] (3), [Cr2Pd3L6(dppp)3](OTf)6 (4) and [Al2Pd3L6(dppp)3](OTf)6 (5) (where HL is 1-(4-pyridyl)butane-1,3-dione and dppp is 1,3-bis(diphenylphosphino)propane) are reported. Neutral cages 1-3 were synthesised using the tritopic [MIIIL3] metalloligand in combination with the salts CoIICl2 and ZnIIBr2, which both act as tetrahedral linkers. The assembly of the cis-protected [PdII(dppp)(OTf)2] with [MIIIL3] afforded the anionic cages 4-5 of general formula [MIII2PdII3](OTf)6. The metallic skeleton of all cages describes a trigonal bipyramid with the MIII ions occupying the two axial sites and the MII ions sitting in the three equatorial positions. Direct current (DC) magnetic susceptibility, magnetisation and heat capacity measurements on 1 reveal weak antiferromagnetic exchange between the FeIII and CoII ions. EPR spectroscopy demonstrates that the distortion imposed on the {MO6} coordination sphere of [MIIIL3] by complexation in the {MIII2MII3} supramolecules results in a small, but measurable, increase of the zero field splitting at MIII. Complete active space self-consistent field (CASSCF) calculations on the three unique CoII sites of 1 suggest DCo ≈ -14 cm-1 and E/D ≈ 0.1, consistent with the magnetothermal and spectroscopic data.

Oman's coral reefs: A unique ecosystem challenged by natural and man-related stresses and in need of conservation

Oman contains diverse and abundant reef coral communities that extend along a coast that borders three environmentally distinct water bodies, with corals existing under unique and often stressful environmental conditions. In recent years Oman's reefs have undergone considerable change due to recurrent predatory starfish outbreaks, cyclone damage, harmful algal blooms, and other stressors. In this review we summarize current knowledge of the biology and status of corals in Oman, particularly in light of recent stressors and projected future threats, and examine current reef management practices. Oman's coral communities occur in marginal environmental conditions for reefs, and hence are quite vulnerable to anthropogenic effects. We recommend a focus on developing conservation-oriented coral research to guide proactive management and expansion of the number and size of designated protected areas in Oman, particularly those associated with critical coral habitat.

Metal-organic fireworks: MOFs as integrated structural scaffolds for pyrotechnic materials

A new approach to formulating pyrotechnic materials is presented whereby constituent ingredients are bound together in a solid-state lattice. This reduces the batch inconsistencies arising from the traditional approach of combining powders by ensuring the key ingredients are 'mixed' in appropriate quantities and are in intimate contact. Further benefits of these types of material are increased safety levels as well as simpler logistics, storage and manufacture. A systematic series of new frameworks comprising fuel and oxidiser agents (group 1 and 2 metal nodes & terephthalic acid derivatives as linkers) has been synthesised and structurally characterised. These new materials have been assessed for pyrotechnic effect by calorimetry and burn tests. Results indicate that these materials exhibit the desired pyrotechnic material properties and the effect can be correlated to the dimensionality of the structure. A new approach to formulating pyrotechnic materials is proposed whereby constituent ingredients are bound together in a solid-state lattice. A series of Metal-organic framework frameworks comprising fuel and oxidiser agents exhibits the desired properties of a pyrotechnic material and this effect is correlated to the dimensionality of the structure.

Occurrence of Cr(VI) in drinking water of Greece and relation to the geological background

This study provides a survey on potential Cr(VI) exposure attributed to drinking water in Greece. For this reason, a wide sampling and chemical analysis of tap waters from around 600 sites, supplied by groundwater resources, was conducted focusing on areas in which the geological substrate is predominated by ultramafic minerals. Results indicate that although violations of the current chromium regulation limit in tap water are very rare, 25% of cases showed Cr(VI) concentrations above 10 μg/L, whereas Cr(VI) was detectable in 70% of the samples (>2 μg/L). Mineralogy and conditions of groundwater reservoirs were correlated to suggest a possible Cr(VI) leaching mechanism. Higher Cr(VI) values are observed in aquifers in alluvial and neogene sediments of serpentine and amphibolite, originating from the erosion of ophiolithic and metamorphic rocks. In contrast, Cr(VI) concentration in samples from ophiolithic and metamorphic rocks was always below 10 μg/L due to both low contact time and surface area, as verified by low conductivity and salt concentration values. These findings indicate that under specific conditions, pollution of water by Cr(VI) is favorable by a slow MnO2-catalyzed oxidation of soluble Cr(III) to Cr(VI) in which manganese products [Mn(III)/Mn(II)] are probably re-oxidized by oxygen.

Nasal dysfunction induced by chlorinate water in competitive swimmers

AIMS

Swimmers commonly complain of nasal symptoms probably due to mucosal irritation caused by chlorinated water. The aim of the present prospective study was to investigate changes in nasal function and cytology in a cohort of 15 volunteer competitive swimmers, as compared with a control group of 15 competitive athletes practicing other sports.

METHODS

Olfactory threshold for n-butanol was measured in a population of competitive swimmers. Changes in nasal function and cytology were compared between the two groups of volunteer competitive athletes.

RESULTS

There were no significant differences between the two groups in terms of mean 20-Item Sino-Nasal Outcome Test scores, peak nasal inspiratory flow, pulmonary peak expiratory flow, or total nasal resistance on anterior active rhinomanometry. Nasal mucociliary transport time (MCTt) was significantly shorter for the non-swimmers than for the swimmers. The mean olfactory threshold for n-butanol in the swimmers was significantly lower than in the other group of athletes.

CONCLUSIONS

Data seem to confirm the utility of MCTt in studying nasal mucosa damage caused by chlorinated water. The present results also support the hypothesis of a role for the olfactory threshold in evaluating damage to the olfactory mucosa exposed to chlorinated water.

Nasal functional modifications after physical exercise: olfactory threshold and peak nasal inspiratory flow

STATEMENT OF PROBLEM

The respiratory nasal effects of physical exercise have been extensively investigated; on the other hand there are no data regarding olfactory threshold modification after aerobic physical exercise.

METHODS

The present prospective study investigated the modifications in nasal respiratory flows and olfactory thresholds after controlled aerobic physical exercise in a cohort of 15 adult, healthy volunteers. The Peak Nasal Inspiratory Flow (PNIF), and the Sniffin’ Sticks olfactory threshold test were used for our determinations.

MAIN RESULTS

The mean PNIF after physical exercise was significantly higher than the mean PNIF value found before physical exercise. Statistical analysis ruled out any significant difference between mean olfactory thresholds pre vs post physical exercise.

PRINCIPAL CONCLUSIONS

These outcomes confirmed PNIF sensitivity and reliability also in determining the changes in nasal patency occurring after physical exercise. The active vasoconstriction of nasal mucosa associated with the reduction of blood flow to the olfactory epithelium due to physical exercise may be compensated for by the increase of olfactory molecules that reach the olfactory mucosa because of nasal mucosal shrinkage: this mechanism could explain the stability of mean olfactory threshold after physical exercise.

An outbreak of influenza A(H1N1)v in a boarding school in South East England, May-June 2009

An outbreak of influenza A(H1N1)v was confirmed in May and June 2009 in a boarding school in South East England involving 102 symptomatic cases with influenza-like illness. Influenza A(H1N1)v infection was laboratory-confirmed by PCR in 62 pupils and one member of staff.

Airway mucus: composition and regulation of its secretion by neuropeptides in vitro

Human and canine airway mucosa in vitro synthesizes and secretes mucus glycoprotein, proteoglycans and lipids which can be separated by density gradient ultracentrifugation in caesium bromide. In secretions from unstimulated explants, the small amount of mucus glycoprotein present is found in association with proteoglycans. 'Free' mucus glycoprotein of typical buoyant density is present only after stimulation of submucosal gland secretion by methacholine. Lipids are synthesized, at least in part, by the airway mucosa and occur in explant secretions as a viscoelastic gel, suggesting that they significantly influence the rheological properties of airway mucus. In addition to cholinergic and adrenergic secretomotor neurons, the airway mucosa is innervated by peptidergic fibres containing immunoreactivity to vasoactive intestinal peptide (VIP) and substance P (SP). In explants of non-bronchitic human airway, VIP inhibits baseline glycoprotein and lysozyme secretion; in canine airway mucosa, by contrast, VIP is a weak partial secretory agonist. SP is the most potent agonist of canine airway glycoprotein release described to date and appears to evoke secretion by a direct action on a stereospecific SP receptor rather than by inducing release of other endogenous secretagogues. VIP and SP have little effect on glycoprotein discharge by mucous and serous cells of the submucosal gland; SP appears to induce secretion by causing contraction of submucosal gland ducts. This may represent the most rapid way for delivering mucus into the airway in response to injury or irritation of airway epithelium.

A 4-year review of balloon dilation of ureteral strictures in renal allografts

BACKGROUND

Ureteral obstruction necessitating intervention occurs in 2% to 7.5% of all renal allograft recipients. Conventional management includes open surgical repair, although more recently, percutaneous ureteral dilation has been performed.

PATIENTS AND METHODS

The management and outcome of all seven allograft ureteral strictures treated with balloon dilation in our unit over a 4-year period were reviewed. Half (55%) of these strictures occurred in the proximal ureter.

RESULTS

Four strictures were dilated successfully with a requirement for five dilations in total. These patients have stable graft function with no evidence of obstruction. Five strictures persisted despite 11 dilations. There were no significant complications from balloon dilation.

CONCLUSION

Definitive surgical management should be considered if obstruction persists after one attempt at ureteral dilation, as multiple dilations have a low success rate (25%).

Preschool healthcare utilisation related to home oxygen status

OBJECTIVE

To determine, in prematurely born children who had bronchopulmonary dysplasia (BPD), if respiratory morbidity, healthcare utilisation, and cost of care during the preschool years were influenced by use of supplementary oxygen at home after discharge from the neonatal intensive care unit.

DESIGN

Observational study.

SETTING

Four tertiary neonatal intensive care units.

PATIENTS

190 children, median gestational age 27 weeks (range 22-31), 70 of whom received supplementary oxygen when discharged home.

INTERVENTIONS

Review of hospital and general practitioner records together with a parent completed respiratory questionnaire.

MAIN OUTCOME MEASURES

Healthcare utilisation, cost of care, cough, wheeze, and use of an inhaler.

RESULTS

Seventy children had supplementary oxygen at home (home oxygen group), but only one had a continuous requirement for home oxygen beyond 2 years of age. There were no significant differences in the gestational age or birth weight of the home oxygen group compared with the rest of the cohort. However, between 2 and 4 years of age inclusive, the home oxygen group had more outpatient attendances (p = 0.0021) and specialist attendances (p = 0.0023), and, for respiratory problems, required more prescriptions (p<0.0001). Their total cost of care was higher (p<0.0001). In addition, more of the home oxygen group wheezed more than once a week (p = 0.0486) and were more likely to use an inhaler (p<0.0001).

CONCLUSIONS

Children with BPD who have supplementary oxygen at home after discharge have increased respiratory morbidity and healthcare utilisation in the preschool years.

Health care utilisation of prematurely born, preschool children related to hospitalisation for RSV infection

BACKGROUND

In prematurely born infants with chronic lung disease (CLD), RSV hospitalisation is associated with increased health service utilisation and costs in the first two years after birth.

AIMS

To determine whether RSV hospitalisation in the first two years was associated with chronic respiratory morbidity during the preschool years in prematurely born children who had had CLD.

METHODS

Retrospective review of readmissions, outpatient attendances, and community care in years 2-4 and, at age 5 years, assessment of the children's respiratory status and their health related quality of life. Comparison was made of the results of children who had had at least one hospitalisation in the first two years after birth for RSV infection (RSV group) to those of the rest of the cohort. Participants were 190 of an original cohort of 235 infants with CLD and a median gestational age 27 (range 22-33) weeks.

RESULTS

The 33 children in the RSV group, compared to the rest of the cohort, had a greater duration of hospital stay and more outpatient appointments. The RSV group had required more prescriptions for all treatments and respiratory medications, and more had used an inhaler. The cost of care of the RSV group was higher (median 2630 pounds sterling [4000 Euros, US4800 dollars], range 124-18,091 pounds sterling versus 1360 pounds sterling [2500 Euros, US3000 dollars], range 5-18 929 pounds sterling ) and their health related quality of life was lower.

CONCLUSION

In prematurely born children who had developed CLD, RSV hospitalisation in the first two years was associated with chronic respiratory morbidity and increased cost of care.

A prospective randomised controlled trial of nutritional supplementation in malnourished elderly in the community: clinical and health economic outcomes

BACKGROUND & AIMS

Malnutrition is common in sick elderly people on admission to hospital and in the community. We conducted a randomised controlled trial to determine if nutritional supplementation after discharge from hospital improved nutritional status and functional outcomes, or reduced health-care costs.

METHODS

Elderly malnourished subjects were randomised to 8 weeks of supplementation or no supplementation post discharge, and followed up for 24 weeks. Weight, body mass index, anthropometrics, handgrip strength, quality of life and requirements for health-care professionals' services and social services were measured throughout the study.

RESULTS

Nutritional status improved significantly from baseline to week 24 in the intervention group (P<0.05), but not in the control group. There was no significant difference in nutritional status between groups at week 24. Handgrip strength improved significantly in the intervention group during supplementation, and was significantly different from that of the control group at week 8, but decreased thereafter. There was no significant difference in quality of life or health economic outcomes between groups at week 24.

CONCLUSIONS

In already malnourished elderly subjects, it may be too late to expect to improve function or quality of life or to reduce health-care costs simply by providing nutritional supplements after hospitalisation. Prevention is key. All elderly patients should be nutritionally assessed as part of their routine care, and appropriate intervention initiated early.

Multidentate Lewis acids: synthesis, structure and mode of action of a redox-based fluoride ion sensor

The mode of action of the bidentate bis(boronate) Lewis acid 2 as a fluoride ion sensor is shown to involve selective anion binding together with an electrochemical response.

Home oxygen status and rehospitalisation and primary care requirements of infants with chronic lung disease

OBJECTIVES

To determine whether the rehospitalisation and primary care requirements of infants with chronic lung disease (CLD) during the first two years after birth were influenced by a requirement for supplementary oxygen after discharge from the neonatal intensive care unit.

METHODS

Review of records from both the hospital and general practitioner.

PATIENTS

235 infants, median gestational age 27 (range 22-31) weeks, 88 of whom were receiving supplementary oxygen when discharged home.

RESULTS

Overall, the infants required a median of 2 (range 0-20) admissions per patient, 8 (0-41) outpatient attendances, 13 (0-76) contacts with the general practitioner, and 17 (0-169) consultations with other primary healthcare professionals. The home oxygen patients required significantly more and longer admissions (p < 0.01) and more outpatient attendances (p < 0.05). The total cost of care per infant of the home oxygen group was greater (p < 0.001); this reflected higher costs for hospital stay (p < 0.01), total inpatient care (p < 0.01), and primary care drugs (p < 0.01).

CONCLUSION

Despite routine use of antenatal steroids and postnatal surfactant, certain patients with CLD, particularly those who receive home oxygen treatment, show high rates of utilisation of health service resources after discharge from the neonatal care unit.

Health care utilisation of infants with chronic lung disease, related to hospitalisation for RSV infection

AIMS

To compare the use of health care resources and associated costs between infants with chronic lung disease (CLD) who had or had not an admission with a proven respiratory syncytial virus (RSV) infection.

METHODS

Review of community care, outpatient attendances, and readmissions in the first two years after birth.

PATIENTS

235 infants (median gestational age 27 weeks) evaluated in four groups: 45 infants with a proven RSV admission (RSV proven); 24 with a probable bronchiolitis admission; 60 with other respiratory admissions; and 106 with non-respiratory or no admissions.

RESULTS

The RSV proven compared to the other groups required more frequent and longer admissions to general paediatric wards and intensive care units, more outpatient attendances and GP consultations for respiratory related disorders, and had a higher total cost of care.

CONCLUSION

RSV hospitalisation in patients with CLD is associated with increased health service utilisation and costs in the first two years after birth.

Comparison of once- and twice-daily clarithromycin in the treatment of adults with severe acute lower respiratory tract infections

BACKGROUND

Although the modified-release (MR) formulation of clarithromycin has demonstrated bioequivalence to the immediate-release (IR) formulation and thus can be prescribed for lower respiratory tract infections (LRTIs), a MEDLINE search from 1995 through 1998 and information on file with the manufacturer indicate that no data are available on the effectiveness of this new formulation in the treatment of severe LRTIs such as community-acquired pneumonia.

OBJECTIVE

This study was designed to compare clinical success rates (percentage of patients with clinical cure or improvement) with once- and twice-daily regimens of clarithromycin in the treatment of patients with severe, acute LRTIs requiring oral antibiotic therapy.

METHODS

In this multicenter, investigator-blinded, randomized, parallel-group study, adult patients with clinical evidence suggesting severe, acute LRTI were recruited from 22 general practices in the United Kingdom. Patients were randomly allocated to receive either clarithromycin 500 mg BID (IR tablets) or clarithromycin 1 g OD (two 500-mg MR tablets) for 7 to 14 days. The outcome measures were resolution of or improvement in clinical signs and symptoms (including resolution of cough), unscheduled visits for the same symptom, days to resumption of normal activities, and improvements in quality of life (assessed using the EQ-5D version of the EuroQoL questionnaire). Clinical, microbiologic, and serologic assessments were performed before, during, and after treatment. Efficacy and safety data were analyzed on an intent-to-treat basis.

RESULTS

One hundred sixty men (n = 83) and women (n = 77) between the ages of 19 and 88 years took part in the study, 78 receiving clarithromycin 500 mg BID and 82 receiving clarithromycin 1 g OD. At 4 weeks after the start of treatment, the high clinical success rates were comparable between groups: 84.6% with clarithromycin 500 mg BID and 90.2% with clarithromycin 1 g OD. No significant differences in outcome measures were noted between the 2 regimens. Both treatments were well tolerated, with taste disturbance being the most commonly reported adverse event (10.6% vs 6.1% with clarithromycin 500 mg BID and 1 g OD, respectively).

CONCLUSIONS

The 2 clarithromycin regimens were equally efficacious and well tolerated in the treatment of severe, acute LRTIs. However, caution should be exercised in applying these results to the general population, because the study excluded certain categories of patients who would normally be treated. In addition, the small sample size may have obscured clinically significant differences between the 2 regimens.

2-amidopyrroles and 2,5-diamidopyrroles as simple anion binding agents

Four new 2-amidopyrroles and 2,5-diamidopyrroles have been synthesized and their anion complexation properties investigated. The crystal structures of these receptors have been elucidated and reveal hydrogen bonding in the solid state leading to dimer and network formation. Selectivity for oxo-anions has been demonstrated by (1)H NMR titration techniques.

Semiparametric models and inference for biomedical time series with extra-variation

Biomedical trials often give rise to data having the form of time series of a common process on separate individuals. One model which has been proposed to explain variations in such series across individuals is a random effects model based on sample periodograms. The use of spectral coefficients enables models for individual series to be constructed on the basis of standard asymptotic theory, whilst variations between individuals are handled by permitting a random effect perturbation of model coefficients. This paper extends such methodology in two ways: first, by enabling a nonparametric specification of underlying spectral behaviour; second, by addressing some of the tricky computational issues which are encountered when working with this class of random effect models. This leads to a model in which a population spectrum is specified nonparametrically through a dynamic system, and the processes measured on individuals within the population are assumed to have a spectrum which has a random effect perturbation from the population norm. Simulation studies show that standard MCMC algorithms give effective inferences for this model, and applications to biomedical data suggest that the model itself is capable of revealing scientifically important structure in temporal characteristics both within and between individual processes.

Patterns of prescribing of nutritional supplements in the United Kingdom

BACKGROUND AND AIMS

A large number of prescriptions are issued for nutritional supplements under British National Formulary classifications 9.4.1 (foods for special diets) and 9.4.2 (enteral feeds), but little is known about the characteristics of the patients who receive them. We used the General Practice Research Database to examine patterns of prescribing of these supplements.

METHODS

We selected patients who had been prescribed supplements under classifications 9.4.1 and 9.4.2 during 1996-1997. Descriptive statistics were used to examine how prescribing varied.

RESULTS

28644 patients received prescriptions during 1996-1997. Among the 27413 (96%) patients prescribed supplements for oral use, 14750 received supplements for enteral nutrition alone, 8122 received supplements for special diets alone and 4541 had both types of supplement. 51% of patients receiving supplements for special diets were <18 years. The commonest diagnoses among such children were milk intolerance (24%) and malnutrition (17%). 94% of patients receiving supplements for enteral nutrition were adult, 52% of whom had cancer or cardiovascular disease. Only 4% of patients had weight and height recorded prior to first prescription.

CONCLUSIONS

The GPRD provides valuable information on the characteristics of patients prescribed nutritional supplements. But because only limited data are available on their nutritional status prior to supplementation, it is hard to assess whether general practitioners are prescribing these supplements appropriately.

trans-4-[(4-dimethylaminophenyl)-iminomethyl]-N-methyllpyridinium para-toluenesulfonate

In the title compound, C15H18N3+*C7H7O3S-, the phenylene and pyridyl rings are somewhat twisted with respect to each other, forming a dihedral angle of 23.49 (6) degrees. The compound contains a dipolar chromophoric cation, but crystallizes in the centrosymmetric space group P2(1)/n and is thus not expected to display quadratic non-linear optical effects.

Prevalence of malnutrition on admission to four hospitals in England. The Malnutrition Prevalence Group

AIMS

The primary objective was to estimate prevalence of malnutrition on admission to four hospitals. Secondary objectives included assessing the relationship between nutritional status and length of hospital stay, numbers of new prescriptions, new infections and disease severity.

METHODS

We entered eligible patients according to predefined quotas for elective and emergency admissions to 23 specialties. We measured height, weight, Body Mass Index and anthropometrics, and recorded history of unintentional weight loss. Patients who had lost > or = 10% of their body weight, had a Body Mass Index <20, or had a Body Mass Index <20 with one anthropometric measurement <15th centile were considered malnourished.

RESULTS

Of 1611 eligible patients, 761 did not participate; 269 were too ill; 256 could not be weighed; and 236 refused consent. Eight hundred and fifty were subsequently evaluated. Prevalence of malnutrition on admission was 20%. Length of stay, new prescriptions and infections and disease severity were significantly higher in the malnourished.

CONCLUSIONS

One patient in every five admitted to hospital is malnourished. Although this figure is unacceptably high, it may underestimate true prevalence. Malnutrition was associated with increased length of stay, new prescriptions and infections. Malnutrition may also have contributed to disease severity.

tert-Butyl 2-[2-(ethoxycarbothioylamino)-3-pyridyloxy]acetate andtert-butyl 2-(3-thioxopyrido[2,1-c][1,2,4]thiadiazol-8-yloxy)acetate

Compounds (I), C(14)H(20)N(2)O(4)S, and (II), C(12)H(14)N(2)O(3)S(2), are two minor products of the same reaction. Both structures contain identical ester functionalities in similar orientations. Both independent molecules of (I) contain an ethoxycarbothioylamine moiety, whilst (II) possesses a novel exocyclic thione system fused with a pyridine ring.

Charge densities from high-resolution synchrotron X-ray diffraction experiments

The combination of intense X-ray sources, especially synchrotron radiation, with area-detector technology has accomplished an enormous advance in the experimental conditions available for charge-density analysis by single-crystal high-resolution X-ray diffraction. Such experiments can now be carried out in a time measured in hours rather than weeks. Some features of these experiments are examined and preliminary results are reported for charge-density studies of 2-hydroxy-5-nitrobenzaldehyde N-cyclohexylimine (1), octakis(m-tolylthio)naphthalene (2), and 7-fluoro-4-styrylcoumarin (3). Weak interactions in crystals of (1) and (3) are found to have similar charge-density characteristics. Cages in the crystal lattice of (2) have a complex charge distribution.

A family of polynuclear cobalt and nickel complexes stabilised by 2-pyridonate and carboxylate ligands

The synthesis and structural characterisation of a series of cobalt and nickel cages are reported. Eight of these structures contain a [M10(mu3-OH)6(eta2, mu3-xhp),(eta2, mu2-O2CR)6]2+ core (where M = Co or Ni; xhp = 6-chloro- or 6-methyl-2-pyridonate: R = Me, Ph, CHMe2, CH2Cl, CHPh2 or CMe3), where the ten metal atoms describe a centred-tricapped-trigonal prism (ttp). The cage contains six hydroxide ligands around the central metal, and the exterior is coated with pyridonate and carboxylate ligands. For four of the cages additional metal centres are found attached to the upper and/or lower triangular faces of the trigonal prism, generating dodeca- and undecanuclear cages. Three further cages are reported that contain a metal core based on an incomplete centred-tetraicosahedron. These cages involve trimethylacetate as a ligand in company with either 6-methyl-2-pyridonate or 6-chloro-2-pyridonate. Comparison of these latter structures with the trigonal prisms reveal that they can be described as a pentacapped-trigonal prism missing one edge. Magnetic studies of three of the nickel cages with trigonal prismatic cores show spin ground states of S = 8, 4 and 2 for Ni12, Ni11 and Ni10 cages, respectively.

Performance characteristics of a low-cost, field-deployable miniature CCD spectrometer

Miniature spectrometers incorporating array detectors are becoming a viable, low-cost option for field and process deployments. The performance characteristics of one such instrument are reported and compared with those of a conventional benchtop instrument. The parameters investigated were wavelength repeatability, photometric linearity, instrumental noise (photometric precision) and instrumental drift.

Outcomes of undernutrition in patients in the community with cancer or cardiovascular disease

Public health concern has tended to focus on the dangers of obesity, but there is evidence that undernutrition may also pose a risk to physical and mental well-being, particularly in those who are already ill. Using the General Practice Research Database (see office for Population Censuses and Surveys, 1995), we followed up 10,128 men and women aged 18 years and over who had been diagnosed with cancer or cardiovascular disease to examine whether nutritional status, as indicated by BMI, affected rates of use of health care resources and mortality. In both diagnostic groups, patients with a BMI below 20 kg/m2 had higher rates of consultation with GP, higher rates of prescription and higher death rates during the follow-up period compared with those with a BMI of 20-< 25 kg/m2. In men and women with cardiovascular disease, poor nutritional status was associated with a sharply increased risk of hospital admission. Patients whose BMI was 30-< 40 kg/m2 also tended to have increased rates of GP consultation and prescription, and if they were under the age of 65 years, they had an increased risk of death. The results of the present study suggest that in men and women with cancer or cardiovascular disease, even minor degrees of undernutrition are associated with a marked increase in morbidity and mortality.

Can non-prosecutory enforcement of public health legislation reduce smoking among high school students?

BACKGROUND

Smoking by adolescents has been identified as a major public health issue. Raising the legal age of cigarette purchase from 16 to 18 years has attempted to address the issue by restricting adolescents' access. METHODS/STRATEGY: A prospective study evaluating the impact of non-prosecutory enforcement of public health legislation involving 'beat police' was conducted in the Northern Sydney Health region. Secondary students, aged 12 to 17 years, from both intervention and control regions were surveyed about cigarette smoking habits by means of a self-completed questionnaire administered pre- and post-intervention.

RESULTS

12,502 anonymous questionnaires were completed. At baseline, 19.3% of male students and 21.2% of female students indicated they were current smokers. Age and sex stratified chi-squared analysis revealed significantly lower post-intervention smoking prevalence for year 8 and 10 females and year 7 males among the intervention group. Higher post-intervention smoking prevalences were demonstrated for year 7 and 9 females and year 8 males among the intervention group and in year 10 males and year 11 females among the control group. The analysis of combined baseline and follow-up data from coeducational schools with logistic regression techniques demonstrated that the intervention had a significant effect in reducing smoking prevalence among year 7 students only (OR = 0.54).

CONCLUSION

Our study demonstrates the difficulties in restricting high school students' access to cigarettes. Isolated non-prosecutory strategies are likely to only have a limited impact on reducing smoking prevalence among high school students.

Effect of nutritional status on use of health care resources by patients with chronic disease living in the community

The prevalence of malnutrition in patients with chronic disease living in the community in the UK is around 8%. Whether such patients experience greater morbidity and mortality or make increased use of health care resources is unknown. The aim of this study was to investigate how the use of health care resources by patients with chronic disorders of the respiratory, gastrointestinal and neurological systems varied by nutritional status. We used longitudinal data, collected since 1987, which formed part of the General Practice Research Database in the UK. Subjects were 11 357 men and women aged 18 years or over. Main outcomes were consultation rates in general practice, prescription rates, hospital referral rates, hospital admission rates and mortality. Consultation and prescription rates were lowest amongst patients whose body mass index (BMI) was between 20 and 25. Rates were higher in patients whose BMI was below 20, or 25 and above. There was no statistically significant relation between rate of hospital outpatient referral and nutritional status, but both hospital admission rate and mortality were greatest in those people whose BMIs were below 20 and declined as BMIs increased. In patients with differential use of health care resources in both primary care and hospital practice, and with differences in mortality.

Comparison of clarithromycin suspension and amoxycillin syrup for the treatment of children with pharyngitis and/or tonsillitis

Twenty-three general practices in the UK randomised 229 paediatric patients (aged 1-12 years, body weight > 8 kg) with clinical evidence suggestive of streptococcal tonsillitis and/or pharyngitis in this physician-blind study. Patients received either clarithromycin suspension (7.5 mg/kg twice daily) or amoxycillin syrup (125 mg/kg three times daily body weight < 25 kg, or 250 mg/kg three times daily body weight 25 kg) for 7 days and were followed up 3-8 days post treatment and 21-28 days later. Clinical and microbiological assessments were made at each visit. A total of 189 patients (98 on clarithromycin and 91 on amoxycillin) were clinically evaluable. At the post-treatment visit, clinical success rates were high and comparable: 98% on clarithromycin and 97% on amoxycillin. Streptococcus pyogenes was eradicated in 88% of clarithromycin patients and 86% of amoxycillin patients. Both treatments were well tolerated. In conclusion, clarithromycin suspension was as safe and at least as effective as amoxycillin syrup for the treatment of pharyngitis and/or tonsillitis in children, and would be a suitable alternative therapy.

Apicoectomy on an incisor tooth of a Victorian koala (Phascolarctos cinereus victor)

An eight-year-old Victorian koala was presented with a discharging mandibular sinus of at least one month duration. On examination, a dental abscess of the right mandibular incisor tooth was found. During the course of endodontic treatment, a size 2 Gates Glidden bur separated from the shank and was lodged in the canal. Due to the anatomy of the tooth the bur could not be removed and an apicoectomy was performed. Following the apicoectomy (follow-up period two years), the periapical pathology resolved.

Prevention of atmospheric contamination during isoflurane sedation

With a view to minimising staff exposure to exhaled isoflurane which had been used for sedation, we assessed the efficacy of either activated charcoal adsorption or active or passive mechanical scavenging systems in intensive care units (ICUs). Personal monitoring revealed minimal exposure of staff to the sedating agent. Infra-red analyses of ambient air rarely showed isoflurane levels greater than 26 ppm, with mean concentrations of around 1 ppm. Small spillages during vaporiser filling were of no polluting significance. The activated charcoal adsorbers functioned highly efficiently for at least 12-hour periods. With simple scavenging techniques, atmospheric isoflurane contamination during sedation with the agent remains well within an acceptable range and is unlikely to pose a health risk to nursing and medical staff.

A comparative study of clarithromycin and amoxycillin suspensions in the treatment of pediatric patients with acute otitis media

This phase III, single-blind, randomized, multicentre clinical trial compared the safety and efficacy of clarithromycin and amoxycillin in the treatment of otitis media in pediatric patients. Two hundred and fifty-nine patients aged 1-12 were prescribed suspensions of clarithromycin (132 patients) or amoxycillin (127 patients). Both suspensions were prescribed at a dose of 125 mg for children weighing less that 25 kg or at 250 mg for children weighing more than 25 kg, but three doses of amoxycillin per day were given, while only two doses clarithromycin per day were required. Each drug was administered for approximately 5 days. Clinical evaluations were performed pre-treatment (Study Day 1), at the end of treatment (Study Days 6-9), and post-treatment (Study Days 28-32). At the end of treatment, 91 out of 114 evaluable patients (80%) had clinical cures with clarithromycin, while 71 out of 105 evaluable patients (68%) had clinical cures with amoxycillin (p = 0.057). Clinical success rates were 96% for both treatments (110/114, clarithromycin; 101/105 amoxycillin). Adverse events related to the study medications occurred in four of 132 patients receiving clarithromycin (3%) and eight out of 127 subjects receiving amoxycillin (6%). Three patients discontinued treatment due to adverse events, all three receiving amoxycillin. At the doses administered, clarithromycin given twice-daily was as safe and effective as given three-times-daily in the treatment of acute otitis media in pediatric patients.

A single-blind, randomised, comparative study of clarithromycin and amoxycillin suspensions in the treatment of children with lower respiratory tract infections

One hundred and forty-five children with signs and symptoms of lower respiratory tract infections were entered into this multicentre, General Practice, investigator-blind study, designed to demonstrate equivalent efficacy between clarithromycin and amoxycillin suspensions. Seventy one children were randomised to treatment with clarithromycin suspension 7.5 mg/kg bodyweight twice daily and 74 to treatment with amoxycillin suspension 125 mg (bodyweight < 25 kg) or 250 mg (bodyweight > or = 25 kg) three times a day according to bodyweight. Duration of therapy was 5-10 days as determined by the investigator. Clinical evaluations were performed pretreatment, during treatment and post-treatment within 72 hours of cessation of therapy. Fifty two children in the clarithromycin group and 57 in the amoxycillin group were clinically evaluable. Both study medications were effective and there were no significant differences between the groups with respect to clinical cure rate (60% for clarithromycin and 63% for amoxycillin), clinical success rate (cure plus improvement, 96% for clarithromycin and 95% for amoxycillin) or rate of resolution of clinical signs and symptoms in clinically evaluable patients. The intention to treat analysis for all patients entered similarly showed no significant differences in efficacy. The two treatment groups did not differ significantly with respect to incidence or severity of adverse events which were generally mild and associated with the gastrointestinal system. Therapy was withdrawn because of adverse events in three children on clarithromycin and one on amoxycillin. Bacteriological cure rates could not be determined because of an insufficient number of evaluable pre-treatment sputum samples.(ABSTRACT TRUNCATED AT 250 WORDS)