Liquid chromatographic determination of 2',3'-dideoxyguanosine in human plasma

A rapid assay for 2',3'-dideoxyguanosine (ddG) in human plasma has been developed. The ddG was first extracted from human plasma using solid phase extraction. The extract containing ddG was then assayed with liquid chromatography using an ODS column and a mobile phase of 9% methanol in pH 6.8 phosphate buffer. The overall method had good accuracy (within 2%), linearity (r = 0.9998), sensitivity (LOD = 1.8 ng, S/N = 3) and recovery (greater than 99% for 5-50 micrograms ddG per ml plasma).

Subcapsular hematoma of the liver during pregnancy

We have reported a case of subcapsular hematoma of the liver, diagnosed and observed by ultrasonography, in association with the HELLP syndrome. The patient's condition improved with conservative management, but the hematoma was clearly shown to last for more than 12 weeks, which shows the need for extended postpartum follow-up and appropriate patient consultation.

Daily living with COPD. Self-help skills to improve functional ability

Although patients with chronic obstructive pulmonary disease (COPD) experience many problems as a result of their disease, they can use numerous strategies to maximize functional ability and maintain health. Patients with COPD should be encouraged to learn more about their disease and use commonsense approaches to management. Referral to a pulmonary rehabilitation program that offers comprehensive assessment, individualized treatment, and access to support groups is also valuable. Rehabilitation programs often result in an improved capability for daily activities and a better quality of life.

Arterial embolization in patients with renal carcinoma

The literature concerning embolization of the renal artery in patients with renal cell carcinoma is reviewed. Based on this review it is concluded that the method is useful in this patient group as it will facilitate the surgical procedure if nephrectomy is performed afterwards. Used as a palliative method, embolization reduces haematuria. It was not possible to draw conclusions concerning survival rates or eventual immuno-stimulating effects of embolization.

Microencapsulation of emulsified oil droplets by in-situ vinyl polymerization

This paper reports on the preparation and evaluation of microcapsules formed by the polymerization of methyl methacrylate in the presence of an oil/water emulsion. The oil phase was composed of an alkane (n-decane or hexadecane) and the oil/water emulsions were stabilized by a variety of emulsifiers. Both oil-soluble and water-soluble initiators were used and the monomer was introduced by either dissolving it in the oil or by feeding it through the water. The primary objective of the work was to study the effects of both formulation and process variables on the morphological characteristics of the polymer/oil composite particle. Our experimental findings indicate that it is not a trivial task to assure that the polymer is formed at the interface in such a way that it envelopes the oil droplet. It was found that the type of emulsifier used is crucial in determining the success of the encapsulation process.

Translation affects immunoglobulin mRNA stability

When termination codons were introduced into exons of the gene for Ig mu chain, steady-state levels of mu mRNA were reduced, both at the pre-B cell stage and at the plasma cell stage. A termination codon in the variable region gene segment and a termination codon in the second exon of the constant region gene segment had effects of similar magnitude. When the termination codon was deleted, the original level of mRNA was restored. The rate of mu gene transcription was the same whether or not a termination codon was present. Therefore, the termination codons must reduce the amount of the mRNA by reducing its stability. Since the introduced termination codons prematurely terminate translation and, in so doing, change the ribosome load on the mRNA, we conclude that mu mRNA stability is conferred in part by ribosomal protection from enzymatic degradation. We propose that the differences in mu mRNA stability during B lymphocyte differentiation are due to different amounts of ribosomes available for translation.

Correction of nonuniform attenuation in cardiac SPECT imaging

Correction for photon attenuation in cardiac SPECT imaging using a measured attenuation distribution with an iterative expectation maximization (EM) algorithm and an iterative Chang algorithm were compared with the conventional filtered backprojection and an iterative EM algorithm without attenuation correction. The attenuation distribution was determined from a transmission computed tomography study that was obtained using an external collimated sheet source. The attenuation of the emitting photons was modeled in the EM algorithm by an attenuated projector-backprojector that used the estimated attenuation distribution to calculate attenuation factors for each pixel along each projection and backprojection ray. Results from a heart-lung phantom study and a 201Tl patient study demonstrated that the iterative EM algorithm with attenuation correction provided improved image quality in terms of reduced streak artifacts and noise, and more accurate quantitative information in terms of improved radioactivity distribution uniformity where uniformity existed, and better anatomic object definition.

Epidural opioids as anaesthesia for extracorporeal shock wave lithotripsy in two patients with cardiac disease

Two patients with cardiac disease underwent Extracorporeal Shock Wave Lithotripsy (ESWL) in the Dornier HM3 machine. In order to minimize cardiovascular changes, epidural opioids (fentanyl 100 micrograms in 10 ml saline was used in one patient and meperidine 50 mg in 10 ml saline in the other patient) were used as an alternative to either general anaesthesia or epidural local anaesthesia. Both patients displayed haemodynamic stability, remained pain-free and experienced no complications. Epidural opioids proved a suitable form of anaesthesia for ESWL in these patients.

Anaesthesia for extracorporeal shockwave lithotripsy at the Victorian Lithotripsy Service--the first 300 patients

A prospective survey was undertaken of the anaesthesia for the first 300 patients at the Victorian Lithotripsy Service. The majority (71.7%) were not hospitalised on site, including four quadriplegics and two ASA grade IV patients. Two hundred and eighty-three (94.3%) patients received continuous lumbar epidural anaesthesia, sixteen (5.3%) received general anaesthesia and one received a spinal anaesthetic. Eighty-two patients (27.3%) underwent ancillary procedures at the time of extracorporeal shockwave lithotripsy. The most common intraoperative complications were hypotension (72 patients, 25.4%) and shivering (39 patients, 13.8%). Arrhythmias occurred in nine (3%) patients. There was a 90% patient follow-up rate and the most common postoperative complication was backache (101 patients, 37.4%). The problems of anaesthesia for extracorporeal shockwave lithotripsy are discussed. Epidural anaesthesia offers a number of advantages for this procedure and proved very suitable for the majority of patients.

Determination of the optimum filter function for SPECT imaging

An observer study was performed in order to evaluate several filters used in SPECT imaging. The filters were applied to the simulated projection data of a uniform activity density cylinder which contained a cold, spherical lesion, 2 cm in diameter. The data incorporated the effects of the detector and scatter response functions, photon attenuation, and noise. Reconstructed transaxial images were used in 2AFC and ROC observer studies testing lesion detectability. In the 2AFC experiment, the Hanning filter scored lowest and did not show a optimum cutoff frequency. The Butterworth filter performed better and showed a well-defined optimum cutoff frequency at 0.15 cycles/pixel. The Metz filter performed as well as the optimum Butterworth but did not show an optimum power factor. In the ROC study, a high power Metz filter demonstrated an ROC curve of lower Az index and different shape from a lower power Metz filter and the optimum Butterworth filter.

Evidence for a high attack rate and efficacy of erythromycin prophylaxis in a pertussis outbreak in a facility for the developmentally disabled

During an outbreak of pertussis in residents and staff of a facility for the developmentally disabled, 149 persons had laboratory evidence of Bordetella pertussis infection; 130 (87%) reported respiratory illness. Infection rates (IR) in affected wards ranged from 6% to 91%. Most residents were adolescents and adults and had received a full course of diphtheria-tetanus toxoids-pertussis (DTP) vaccine; IRs increased with increasing time after the last DTP dose in fully vaccinated residents. The IR was lower in residents on wards where erythromycin treatment/prophylaxis was started two or fewer weeks after the onset of illness in the first case on the ward (IR, 16%), compared with four or more weeks after onset (IR, 75%; P less than 10(-6)). Respiratory symptoms were milder in ill residents treated within seven days of onset of illness. Although B. pertussis transmission was substantial, erythromycin treatment of patients and prophylaxis of exposed persons was effective in decreasing transmission and disease severity. Carbamazepine toxicity occurred in seven (19%) of 37 residents when carbamazepine was administered with erythromycin.

Anorexia tardive: a diagnosis of exclusion?

An elderly female patient is described in whom rapid severe weight loss appeared initially to be of psychogenic origin and self-induced. A diagnosis of late-onset anorexia nervosa or anorexia tardive was made when early investigations revealed no abnormality apart from changes that were consistent with malnutrition, and when typical behavioural and psychological factors together with putative psychodynamic issues were revealed. At first, nasogastric feeding was beneficial, but a stormy hospital course ensued. Further investigations revealed the presence of neoplastic disease which at post-mortem examination proved to be small-cell carcinoma of the lung.

Malignant mesothelioma secondary to chronic inflammation and old scars. Two new cases and review of the literature

Old scars of the pleura, for example from chronic empyema or therapeutic pneumothorax, can cause a malignant mesothelioma appearing some decades later. The authors describe two cases of primary pleural tumors, which probably had such an etiology. A literature review revealed 20 further cases, the majority of which were squamous cell carcinomas. Whether these tumors developed from metaplastic mesothelium or inplanted cells from the skin is not clear.

A special cut-off gamma camera for high-resolution SPECT of the head

A modern system for single photon emission computerized tomography has been modified in order to optimize examinations of the head. By cutting off part of the detector housing and collimators at one edge, it is possible to rotate the camera close to the skull while still covering the entire brain and the skull base. The minimum radius of revolution used in 32 patients was thereby reduced from about 20 cm to 12.7 +/- 0.8 cm. This, combined with an adjustment of the 64 X 64 matrix to a 26- by 26-cm field of view, resulted in an improvement of the spatial resolution from about 19 mm to 12.6 +/- 0.3 mm with a low-energy, all-purpose collimator, and to 10.4 +/- 0.3 mm (FWHM) with a low-energy, high-resolution collimator. The improved spatial resolution offers several clinical advantages in studies of the brain, the cerebrospinal fluid space, and the skull base.

Dual role of the liver in regulating circulating polymeric IgA in man: studies on patients with liver disease

The human liver probably removes circulating polymeric IgA by two routes: (1) secretory component-mediated endocytic transport of polymeric IgA from portal tract blood vessels into bile across biliary epithelial cells and (2) uptake with possible catabolism by hepatocytes and/or sinusoidal phagocytic cells by uncharacterized receptor(s). Failure of either clearance mechanism due to liver disease results in elevated serum polymeric IgA levels. In patients with cholestasis, the raised serum polymeric IgA concentration is due to reflux of biliary secretory immunoglobulin into the blood.

Extreme leucocytosis and prognosis of newly diagnosed patients with acute non-lymphocytic leukaemia

A group of 87 consecutive patients with acute non-lymphocytic leukaemia (ANLL) who had been treated with large doses of hydroxyurea (HU) as a preliminary to protocol combination chemotherapy is reviewed. The outcome in patients whose initial leucocyte count was 100x10(9)/L or higher (HC group) is compared with that in the majority who had lower leucocyte counts. Contrary to reports in the literature, patients in the HC group had the same chance of achieving remission as the rest, and the survival of the responders was equally long in both groups. There were no deaths from intracerebral haemorrhage in the reportedly high-risk HC group, a fact which was attributed to the administration of HU to all new patients. Hydroxyurea rapidly lowered the leucocyte count in nearly all patients with ANLL and appeared to be a valuable addition to protocol therapy of this disease.

Barbiturate dependence in mice: effects of continuous vs. discontinuous drug administration

Three groups of DBA/2J mice were continuously exposed for 3, 6 or 9 days to a milled diet containing phenobarbital. Two additional groups were given a discontinuous drug administration schedule with either one or two 24 h drug-free periods interpolated among the 6 or 9 days of phenobarbital consumption, respectively. The discontinuous schedule of drug administration significantly attenuated the development of physical dependence as determined by the severity of withdrawal symptoms. Functional tolerance development was also attenuated in a manner that closely paralleled the effects on physical dependence development. The 5 group means showed a perfect rank order correlation between functional tolerance and physical dependence development.

Controlled drug release from polymeric delivery devices. III: In vitro-in vivo correlation for intravaginal release of ethynodiol diacetate from silicone devices in rabbits

Forty female rabbits were implanted with silicone vaginal devices containing ethynodiol diacetate for up to 8 weeks. As predicted from in vitro studies, a Q - t1/2 (matrix-controlled) release profile was observed in vivo. The in vivo drug release profile was compared with in vitro data measured at three hydrodynamic conditions, and the diffusional resistance across the vaginal wall was estimated. Drug released from silicone devices yielded a prolonged plasma level when compared with data following intravaginal or intravenous administration of a solution dose. The rate constant for elimination was unchanged. The plasma concentration of the drug was related to the intravaginal drug release profile both theoretically and experimentally and was above the concentration required to inhibit fertilization.

The biological significance of mongolism

Professor Penrose turned his attention to the subject of mongolism at a very early stage in his professional career and retained an undiminished interest in all facets of the problem for more than 40 years. His first publication in this sphere was in 1931 (1) and was entitled ‘The creases on the minimal digit in mongolism’. The observations he made in this publication are typical of some of his later ones. It reflected a mind alert to useful detail, in this case the fact that in some mongols there is only one flexion crease on the fifth digit instead of two. This peculiarity rarely occurs in the normal population and therefore provides an additional diagnostic criterion for mongolism. Particularly at a time when chromosomal examination could not be undertaken, this direct simple observation helped in the clinical delineation of a condition which is not always easily recognized.

Temporary suppression of Streptococcus mutans in humans through topical application of vancomycin

Vancomycin, an antibiotic with desirable properties for oral usage, was applied in a 15% gel formulation to the teeth of children, and as a 1% paste to the teeth of young adults. Temporary suppression was observed in the presence of Streptococcus mutans, an organism which has been implicated in human dental caries.