Preparative purification of supercoiled plasmid DNA using anion-exchange chromatography

Large scale manufacturing of gene vectors such as plasmid DNA is an important issue in gene therapy. Anion-exchange chromatography is fundamental in the downstream processing of plasmids both as a process and analytical technique. This work reports the use of Q-Sepharose columns (1, 10 and 40 ml) for the preparative purification of plasmid pUC18. NaCl gradient elution enabled the isolation of supercoiled plasmid from low-M(r) RNA, cDNA and plasmid variants. A compact covalently closed, supercoiled form of denatured plasmid carrying large stretches of single-stranded DNA was identified as one of the major contaminants. Anion-exchange HPLC on a Poros QE 20 column was used to quantify plasmid yield. Supercoiled plasmid was recovered in a single fraction with a 62 +/- 8% yield. Loadings higher than 40 micrograms/ml gel could be used but at the expense of a loss of resolution between open circular and supercoiled forms. Plasmid quality was evaluated by gel electrophoresis, restriction analysis, transformation experiments and protein assays.

A controlled trial of metoclopramide in symptomatic gastroesophageal reflux

Since metoclopramide increases lower-esophageal-sphincter pressure in patients with gastroesophageal reflux, we compared the effects of metoclopramide, 10 mg four times daily, with those of placebo on symptoms in 31 patients with chronic heartburn. Eighteen patients completed a random-order, double-blind crossover study of two consecutive eight-week periods. The final 13 patients crossed over only if their symptoms were not substantially improved after the first eight weeks. Response of low-esophageal-sphincter pressure to metoclopramide did not correlate significantly with symptomatic improvement. After the metoclopramide treatment period, mean basal pressure was unchanged from values before study. In both treatment periods, metoclopramide-treated patients had significantly more symptomatic improvement than the control group (P less than 0.05).

An epidemic of pseudomembranous colitis: importance of person to person spread

Twenty three cases of pseudomembranous colitis (PMC) occurred in three hospitals in 10 months. Retrospective analysis shows that they represented a single epidemic with a readily traceable chain of person-to-person contact within and between hospitals. Most patients had severe pre-existing illness and all had broad spectrum antibiotics, including either ampicillin/amoxycillin, a broad spectrum cephalosporin (particularly cefotaxime), or both. All patients had severe diarrhoea and all responded to vancomycin, but relapse occurred in five. Ten patients eventually died, principally because of underlying disease rather than from PMC. Failure to find fibrin thrombi in blood vessels in biopsies and the scanty distribution of non-invasive bacteria supports the concept of mucosal damage by bacterial toxin, rather than by direct infection, or ischaemia. Although environmental colonisation cannot be excluded, the observed pattern of spread suggests a major role for direct person-to-person crossinfection in the spread of disease in this outbreak.

Elder abuse and dementia--a pilot study

An anonymous postal questionnaire was distributed to 200 members of a voluntary organisation providing information and support for the carers of dementia sufferers. Carers were asked about the possible occurrence of verbal, physical abuse and neglect. Those carers who admitted to any form of abuse were compared with those who did not and risk factors in both carers and patients were analysed to determine risk factors for abuse. Fifty-five per cent of carers admitted to some form of abuse with verbal abuse being the most common form. Verbal abuse was associated with a poor premorbid relationship and social isolation of the carer and was found to be a risk factor for physical abuse. Those carers who had high GHQ scores and who had been caring for longer were more likely to physically abuse the person they cared for. This study supports the hypothesis that various categories of abuse have different correlates.

Heparinase III from Flavobacterium heparinum: cloning and recombinant expression in Escherichia coli

Heparinase III (E.C. 4.2.2.8), formerly heparinase I, produced by Flavobacterium heparinum is an enzyme that specifically cleaves heparan sulfate-rich regions of acidic polysaccharides. In this study, we report the cloning of the heparinase III gene using polymerase chain reaction (PCR). Two degenerate oligonucleotides, based on amino acid sequences derived from tryptic peptides of purified heparinase III were used to generate a approximately 1100-bp probe by PCR amplification using Flavobacterium genomic DNA as the template. The PCR-derived probe was used to screen a Flavobacterium genomic DNA library in lambda ZAP II. The open reading frame of the heparinase III gene is 1980 bp in length, encoding a precursor protein of 75,950 Da; 10 of the tryptic peptides mapped onto the open reading frame which corresponded to approximately 18% of the protein. Recombinant heparinase III was expressed in Escherichia coli using the T7 polymerase pET expression system. This is the first report of the cloning and recombinant expression of an enzyme primarily degrading heparan sulfate.

Carer informants for dementia sufferers: carer awareness of cognitive impairment in an elderly community-resident sample

By comparing data obtained from the carers of 170 community-resident dementia sufferers with the results of objective cognitive testing, we assessed carer awareness of a range of cognitive deficits in their dependents. Spouses living with demented patients were the best at estimating the overall severity of cognitive impairment, whereas both first-degree (particularly if living with the dementia sufferer) and second-degree relatives were better at identifying and reporting the severity of memory impairment and topographical disorientation. Only one carer was aware of problems with object recognition, although a definite problem was detected in at least 40% of the study group. The testing instruments used (MMSE and CAMCOG) probably under-detected dysnomia and appeared to be inconclusive when compared with carer reports of difficulties that could be attributable to dyspraxia, highlighting the problem of sole reliance on either these instruments or informant accounts to obtain accurate clinical information.

Maternal and neonatal hyponatraemia: a comparison of Hartmanns solution with 5% dextrose for the delivery of oxytocin in labour

We performed a randomised controlled trial to compare the effect on neonatal and maternal serum sodium of using oxytocin in Hartmanns solution compared to the standard 5% Dextrose regimen for induction or augmentation in labour. We found significantly decreased maternal and neonatal serum sodium concentrations in the 5% Dextrose group compared to the Hartmanns group.

Use of drugs by Old Age Psychiatrists in the treatment of psychotic and behavioural symptoms in patients with dementia

The objective was to elicit the prescribing practises of Old Age Psychiatrists in the UK in the treatment of psychotic and behavioural symptoms in patients with dementia. A structured questionnaire was sent to all Old Age Psychiatrists in the United Kingdom. Respondents were questioned regarding their use of both typical and atypical antipsychotics and the most common dosages prescribed. Information was sought about usage of depot medication and dosages; use of alternative or adjunctive medications to antipsychotics and use of parenteral medication for acute management of agitation. The most commonly used antipsychotic to treat psychotic symptoms was haloperidol, and thioridazine to treat behavioural symptoms. A wide range of dosages was used. Use of depot medication was common, with flupenthixol decanoate being the most frequently used. Most respondents use at least one of the atypical antipsychotics, risperidone being most popular. Use of other psychotropic medication used as alternatives to antipsychotics or adjunctives in the treatment of behavioural symptoms was common, the most popular being trazodone. Of the respondents, 62.7% use parenteral medication for the acute management of agitation, the most popular drug being haloperidol. The typical antipsychotics are still the most commonly used despite the reputed better safety profile of the atypicals. There was wide variation in the dosages prescribed. Use of psychotropics other than phenothiazines was common. More research is needed into the use of psychotropic medication for dementia and there is need for consensus in this area. Forming an expert group may be the best way to create uniformity of prescription.

Patient attitudes to perioperative suppository administration for postoperative analgesia

Four hundred surgical patients were questioned preoperatively to ascertain their attitudes to suppository analgesia. Given a choice, 82 per cent of patients expressed a preference for intramuscular administration of diclofenac, with 18 per cent choosing a suppository. Males were more likely than females to choose an intramuscular injection. Males choosing a suppository were more likely to belong to a higher socio-economic group while females choosing a suppository were more likely to be married. Twenty-three per cent of patients who initially opted for intramuscular administration changed to suppository administration when the possibility of pain or discomfort at the injection site was explained. Females who changed to suppository administration were more likely to belong to a higher socio-economic group and to be married. Twenty-seven per cent of patients choosing an intramuscular injection expressed concern if a suppository were to be inserted without consent. Eleven per cent of patients choosing a suppository expressed similar concern. There is an overall reluctance, particularly within the male population to accept suppository analgesia. Patients from higher socio-economic groups may be more willing to accept what they perceive to be less traditional forms of treatment.

The use of EMLA reduces the pain associated with digital ring block for ingrowing toenail correction

Treatment of ingrowing toenail is commonly performed under local anaesthesia with a digital ring block. Ring block can be associated with significant pain, caused by needle insertion and deposition of the local anaesthetic agent. EMLA, a topical anaesthetic cream, is widely used to alleviate the pain of venepuncture. The aim of this study was to investigate whether the discomfort of digital block could be reduced by prior application of EMLA. Fifty-five patients who were scheduled for ingrowing toenail under local anaesthesia were randomized into two groups. In Group 1 (n = 30), EMLA was applied around the base of the affected hallux for at least 1 h before ring block. In Group 2 (n = 25), a placebo cream was used. In this double-blind study, patients assessed the pain caused by a standardized ring block using 100-mm visual analogue pain score. The mean visual analogue pain score in Group 1 was 28.1 and 50.1 in Group 2 (P < 0.0001). We conclude that EMLA significantly reduces the pain associated with digital ring block.

Circulating cerebriform lymphoid cells (Sezary-type cells) in a B-cell malignant lymphoma

Circulating cerebriform lymphoid cells (Sezary cells) are considered to be highly predictive of cutaneous T-cell Lymphoma (CTCL). A leukemic peripheral blood (leukocyte count 24.5 x 10(9)/l) composed predominantly of cerebriform cells was found in a 75-year-old man presenting with weight loss and generalized lymphadenopathy but without skin lesions. Cell suspensions studies and immunohistochemistry of peripheral blood revealed that the cerebriform cells were B-cells (IgM+ Kappa+, HLA DR+, Leu 1+, CALLA-, B1+, and OKT 10+). A variety of T-cell markers (other than Leu1) was negative. Computer-assisted morphometry confirmed a nuclear profile typical of CTCL (mean nuclear contour index, 7.47). A lymph node that underwent subsequent biopsy revealed a follicular malignant lymphoma of small to intermediate cells with similar morphologic and immunologic characteristics to the circulating cerebriform cells. The findings of a leukemic presentation of a cerebriform B-cell lymphoma extends the recent observation of nodal B-cell lymphomas composed of cerebriform cells and indicates that circulating cerebriform cells should not be considered to be exclusively of T-cell origin.

Nursing diagnosis: implications for health, with particular concerns for community nursing

As nursing terminology develops to include positive health/wellness related concepts, the appropriateness of nursing diagnoses is questioned. Nursing diagnoses have the potential to lead community nurses towards a reductionist and simplistic view of the complexities associated with community issues. Concerns and questions are raised in relation to the acceptance of nursing diagnoses in Australian community nursing practice.

Outcomes of mature primiparas in an out-of-hospital birth center

This is a retrospective chart review of perinatal outcomes of all primiparas over the age of 24 delivering at Maternity Center Associates, an out-of-hospital birth center, from January 1985 through May 1988 (N = 228). Chi-square analysis was used to determine whether mature primiparas, aged 35 to 43 (n = 27), had significantly more adverse outcomes than younger primiparas, aged 25 to 34 (n = 201). There was a significant difference between the groups in rate of transfer to hospital; however, there were no significant differences in rate of cesarean section, infant birth weight, apgar scores, and length of second stage labor. Implications for practice and future study are examined.

The homeless

The medical literature on homeless people tends to concentrate on their biographic characteristics or clinical problems without enough attention being given to the social and environmental contexts which they have to survive. This article summarises the literature on the role of social factors in the causation and outcome of health problems of the homeless and emphasises the importance of addressing the social context in effecting intervention. Services that deal with the social needs of the homeless will be more successful in meeting their needs and reducing their distress.

Induction of lambda prophage by 213 nm laser radiation: a quantitative comparison with 193 nm excimer radiation using image analysis

We compared the DNA damage produced by radiation from two UV laser wavelengths, 213 nm and 193 nm, with that produced by noncoherent 254 nm radiation. Following irradiation of Escherichia coli BR339, a bacteriophage lambda lysogen containing the lacZ gene, pro-phage induction was measured by assaying for beta-galactosidase. Because of the limited penetration by UV laser wavelengths an agar overlay of the lysogen was used as the irradiation target. Irradiation of 254 nm was performed in buffer suspension followed by transfer of 5 microL spots onto assay plants. Computer image analysis was used to monitor the rate of product formation, observed as an increase in optical density of the irradiated zones on assay plates. We found that the rate of product formation was a more reproducible unit of comparison than the optical density present at the end of the reaction. Although the rate of product formation was not linearly related to enzyme concentration, the data could be fit to a simple logarithmic function. Using this method, we concluded that the DNA damaging ability of 213 nm radiation was 10 times more efficient than 193 nm radiation and about 100 times less efficient than 254 nm noncoherent radiation.

Imaging Barrett's oesophagus

Eight patients who had Barrett's oesophagus confirmed by histology are presented. All had barium swallow examinations and technetium-99m sodium pertechnetate (99Tcm-pertechnetate) scintigraphy, the findings of which are reviewed and discussed. The most valuable diagnostic signs on barium swallow examination related to the site of the stricture and the presence of mucosal outpouchings. Scintigraphy was positive in all eight cases. Patients suspected of having Barrett's oesophagus on barium swallow examination should undergo scintigraphy. When the latter is positive, the endoscopist should be alerted to obtain biopsies not only at the site of stricture but serially as far as the gastrooesophageal junction.