An unusual case of stridor after thyroidectomy

Twelve days after subtotal thyroidectomy, an air pocket developed in a patient's neck. The pressure in this pocket had gradually increased as small amounts of air, probably associated with coughing, came out of a tiny hole in the trachea to form a pneumocoele. This produced limited surgical emphysema, causing venous congestion and oedema of the soft tissues of the larynx, which in turn led to increasing airway obstruction. We believe that this is the first reported case of a pneumocoele that gradually increased in size, causing airway obstruction that was almost certainly due to secondary laryngeal oedema.

Studies on the putative interactions between the organophosphorus insecticide Phosmet and recombinant mouse PrP and its implication in the BSE epidemic

It has been suggested that exposure of cattle to the ectoparasiticide Phosmet in the 1980s caused a conformational change in the cellular prion protein (PrP(C)) to form the BSE prion (PrP(SC)), which initiated the epidemic of bovine spongiform encephalopathy (BSE). Recombinant mouse cellular prion (r[mouse]PrP(C)) was exposed to the organophosphorus pesticide Phosmet in vitro and the conformation of the prion before and after exposure was monitored using circular dichroism (CD) spectroscopy, utilizing synchrotron radiation at the Council for the Central Laboratory of the Research Councils (CLRC) facilities at Daresbury, UK. Metabolites of Phosmet, generated in situ by rat microsomes, were investigated in the same way, to determine whether they might initiate the conformational change due to their high chemical reactivity. Our studies showed that exposure of r[mouse]PrP(C) to Phosmet or microsomes-generated metabolites of Phosmet did not result in the conformational change in the protein from alpha-helix to beta-pleated sheet that is characteristic of the PrP(C) to PrP(SC) conversion and, therefore, Phosmet is very unlikely to have initiated the BSE epidemic by a simple direct mechanism of conformational change in the prion protein.

Prevalence of, and risk factors for, physical ill-health in people with Prader-Willi syndrome: a population-based study

The medical findings from a population-based study of Prader-Willi syndrome (PWS) are discussed (in which birth incidence of PWS was estimated at 1:22,000 and death rate at over 3% per annum). In this study the prevalence of specific medical disorders that might account for a shortened life expectancy were investigated. Of all people with a possible diagnosis of PWS, only those meeting clinical criteria and/or with a confirmed genetic diagnosis were included in the study. Sixty-six individuals, 40 males and 26 females with a mean age of 19 years (range of 0 to 46 years) agreed to participate in the population-based study group. A prevalence rate of 25% for non-insulin dependent diabetes mellitus (NIDDM) was found in adults. Mean age at onset was 20 years. Those with NIDDM had a higher past maximum body weight and a greater likelihood of positive family history. Nearly 50% across the age groups reported a history of recurrent respiratory infections. High rates of fractures (29%), leg ulceration (22% in adults), sleep disorders (20%), and severe scoliosis (15% in childhood) were also reported. It is postulated that hypotonia is a possible contributory factor to the risk of strabismus, scoliosis, and respiratory infections. Other causes of morbidity, in particular the high rates of NIDDM, may be due to a failure to manage over-eating resulting in severe obesity. Early diagnosis and clear guidance to families about these risks and how they might be prevented is recommended. It is hypothesized that the high pain threshold may result in the presence of some illness not being apparent.

Flexible sigmoidoscopy in general practice

OBJECTIVE: Flexible sigmoidoscopy (FS) is increasingly being accepted as the method of choice for initial investigation of rectal bleeding and other lower gastrointestinal symptoms. The aim of this study was to assess the feasibility of FS in general practice and to compare the yield, cost and efficiency of a service provided by a consultant surgeon and a General Practitioner (GP). SUBJECTS AND METHODS: A prospective study of FS was undertaken on 430 unsedated patients with symptoms suggestive of lower bowel disease in two general practices. RESULTS: The yield was comparable to hospital based data. Fifteen (3.5%) cancers were detected, of which 40% were Dukes A, and 46 (10.7%) adenomatous polyps. Cost per patient examination by a GP including capital costs, depreciation of equipment, and training was calculated to be cheaper or at least equivalent to a hospital-based service but inefficient due to the low numbers examined per month. There were no complications and no missed cancers after a minimum follow up of 2 years. CONCLUSIONS: The results suggest that FS can be safely performed by a suitably trained GP in health centres, but better utilization of equipment and value for money would be obtained by providing the service for a group of practices rather than a single practice as in this study.

Pulmonary barotrauma-induced cerebral arterial gas embolism with spontaneous recovery: commentary on the rationale for therapeutic compression

Pulmonary barotrauma-induced cerebral arterial gas embolism (CAGE) continues to complicate compressed gas diving activities. Inadequate lung ventilation secondary to inadvertent breath holding or rapid buoyant ascent can quickly generate a critical state of lung over-pressure. Pulmonary over-pressurization may also occur as a consequence of acute and chronic pulmonary pathologies. Resulting barotrauma frequently causes structural failure within the terminal distal airway. Respiratory gases are then free to embolize the systemic circulation via the pulmonary vasculature and the left heart. The brain is a common target organ. Bubbles that enter the cerebral arteries coalesce to form columns of gas as the vascular network narrows. Small amounts of gas frequently pass directly through the cerebral circulation without occlusion. Larger columns of gas occlude regional brain blood flow, either transiently or permanently, producing a stroke-like clinical picture. In cases of spontaneous redistribution, a period of apparent recovery is frequently followed by relapse. The etiology of relapse appears to be multifactoral, and chiefly the consequence of a failure of reperfusion. Prediction of who will relapse is not possible, and any such relapse is of ominous prognostic significance. It is advisable, therefore, that CAGE patients who undergo spontaneous recovery be promptly recompressed while breathing oxygen. Therapeutic compression will serve to antagonize leukocyte-mediated ischemia-reperfusion injury; limit potential re-embolization of brain blood flow, secondary to further leakage from the original pulmonary lesion or recirculation of gas from the initial occlusive event; protect against embolic injury to other organs; aid in the resolution of component cerebral edema; reduce the likelihood of late brain infarction reported in patients who have undergone spontaneous clinical recovery; and prophylax against decompression sickness in high gas loading dives that precede accelerated ascents and omitted stage decompression.

A survey of attitudes to parent-doctor conflicts over treatment for children

AIMS

To investigate professional and public attitudes to the intervention of the law when parents and doctors disagree about the medical treatment of children.

METHODS

A cross-sectional survey of academic staff at the University of Otago. Random samples of academic medical practitioners and non-Health Sciences academic staff completed written questionnaires, including open and closed questions. Questions focussed on the Liam Williams-Holloway (W-H) and Tovia Laufau (TL) cases.

RESULTS

The response rate was 107/164 (65%) of eligible staff. Support for doctors seeking treatment orders was strong (77% in the W-H case, and in the TL case, 70% believed an order should have been sought). Women were less likely than men to support a treatment order, significantly in the W-H case. There were no significant differences between medical and non-medical respondents. Court processes were viewed as confrontational and a last resort only after mediation failed. Scientific evidence was rated as the most important consideration in treatment decisions, followed by likely outcome, establishment of trust between parents and doctors, and the age of the child.

CONCLUSIONS

Among this highly educated group there was strong support for seeking treatment orders in the child's best interests. But various mediation options were preferred and should be explored further. More evidence is needed on the success of treatment orders and on the attitudes of a more representative sample of the population.

Evidence for the regulation of levels of plasma adhesion molecules by proinflammatory cytokines and their soluble receptors in type 1 diabetes

OBJECTIVES

To investigate the regulation of soluble adhesion molecules by tumour necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6), and relationships with circulating cytokine receptors, in vivo, in type 1 diabetes.

DESIGN

Cross-sectional study.

SETTING

University hospital diabetes clinic.

SUBJECTS

A total of 47 non-nephropathic, Caucasian type 1 diabetics and 39 nondiabetic controls.

OUTCOME MEASURES

Plasma levels of TNF-alpha, IL-6, their soluble receptors and adhesion molecules intercellular adhesion molecule-1 (sICAM-1), vascular cell adhesion molecule-1 (sVCAM-1), sE-selectin and von Willebrand factor (vWF), and risk factors for cardiovascular disease.

RESULTS

Plasma concentrations of IL-6 were elevated in diabetic patients compared with controls [median (interquartiles) 1.28 (0.89-2.65) vs. 0.66 (0.45-1.73) pg mL(-1): P=0.016], and in these patients IL-6 and soluble IL-6 receptor (sIL-6R) levels correlated with concentrations of sICAM-1 (r = 0.41, P = 0.012 and r = 0.31, P = 0.04, respectively). Tumour necrosis factor-alpha soluble receptor-2 (sTN-FRII), but not TNF-alpha or tumour necrosis factor soluble receptor-1 (sTNFRI), was elevated in diabetic subjects (P = 0.027). Plasma TNF-alpha levels correlated with sVCAM-1 (r = 0.39, P = 0.008), triglycerides (r = 0.36, P = 0.02 1) and diastolic blood pressure (r = 0.35; P = 0.024). Both sTNFRI and sTNFRII correlated with blood pressure (r = 0.46, P = 0.002; r = 0.32, P = 0.034) and triglycerides (r = 0.33, P = 0.033; r = 0.29, P = 0.05). In contrast, HDL-cholesterol and triglyceride were related to sE-selectin (r = -0.45 and +0.45; both P < 0.001). Neither sE-selectin nor vWF were related to cytokine concentrations. Finally, both TNF-alpha and sIL-6R correlated sTNFRI and RII (r = 0.44-0.49, P < 0.001). None of these interactions were apparent in control subjects.

CONCLUSIONS

(i) IL-6, through effects on sICAM-1, and TNF-alpha via effects on sVCAM-1, may promote vascular adhesion; (ii) plasma levels of TNF-alpha are associated with dyslipidaemia and increased blood pressure, adding to vascular disease risk; (iii) the actions of both cytokines are probably modified by altered production of soluble receptors in diabetic subjects.

Differentiation potential of adult stem cells

In many different adult tissues, stem cells generate new cells either continuously or in response to injury. Such cells were thought to be limited to generating the types of cells normally present in the tissue where the stem cell resides. However, several different stem-cell populations in the adult have been found recently to be capable of generating additional cell types under certain conditions.

Temporal autocorrelation function for a diffusing-wave spectroscopy experiment with a point source and backscattering detection

The autocorrelation function of the backscattered intensity in a diffusing-wave spectroscopy experiment that uses a point source is calculated by use of the diffusive-wave model. We show that in this approximation the calculated autocorrelation function decays faster than if the plane-source approximation were used. The design of a probe that implements this geometry is presented together with preliminary results that show the utility of the probe as a sizing tool in concentrated dispersions.

Automated multiplex assay system for simultaneous detection of hepatitis B virus DNA, hepatitis C virus RNA, and human immunodeficiency virus type 1 RNA

We have developed an automated multiplex system for simultaneously screening hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus type 1 (HIV-1) in blood donations. The assay, designated AMPLINAT MPX HBV/HCV/HIV-1 Test (AMPLINAT MPX), consists of virus extraction and target sequence-specific probe capture on specimen preparation workstation GT-X (Roche Diagnostics K.K., Tokyo, Japan) and amplification and detection by TaqMan PCR on the ABI PRISM 7700 Analyzer (Perkin-Elmer Applied Biosystems, Foster City, Calif.). An internal control (IC) is incorporated in the assay to monitor the extraction, target amplification, and detection processes. The assay yields qualitative results without discrimination of the three targets. Detection limits (95% confidence interval) are 22 to 60 copies/ml for HBV, 61 to 112 IU/ml for HCV, and 33 to 66 copies/ml for HIV-1, using a specimen input volume of 0.2 ml. The AMPLINAT MPX assay detects a broad range of genotypes or subtypes for all three viruses and has a specificity of 99.6% for all three viruses with seronegative specimens. In an evaluation of seroconversion panels, the AMPLINAT MPX assay detects HBV infection an average of 24 days before the detection of HBsAg by enzyme immunoassay. HCV RNA was detected an average of 31 days before HCV antibody. HIV-1 RNA was detected an average of 14 days before HIV-1 antibody and an average of 9 days before p24 antigen. The Japanese Red Cross has been evaluating the AMPLINAT MPX system since October 1999. The clinical performance indicates that the AMPLINAT MPX system is robust, sensitive, and reproducible, with a high percentage of valid assay runs (96.8%), a low false-positive rate (0.34%), and a low IC failure rate (0.24%).

Macrophages transfected with adenovirus to express IL-4 reduce inflammation in experimental glomerulonephritis

Nephrotoxic nephritis (NTN) is characterized by acute macrophage-dependent inflammation and serves as a model of human glomerulonephritis. In this study we have transfected rat macrophages with recombinant adenovirus expressing IL-4 (Ad-IL4) and demonstrated that these transfected macrophages develop fixed properties as a result of transfection, as shown by reduced NO production in response to IFN-gamma and TNF. Ad-IL4-transfected macrophages localized with enhanced efficiency to inflamed glomeruli after renal artery injection in rats with NTN compared with adenovirus expressing beta-galactosidase (Ad-beta gal)-transfected macrophages and produced elevated levels of the cytokine in glomeruli in vivo for up to 4 days. The delivery of IL-4-expressing macrophages produced a marked reduction in the severity of albuminuria (day 2 albuminuria, 61 +/- 15 mg/24 h) compared with unmodified NTN (day 2 albuminuria, 286 +/- 40 mg/24 h; p < 0.01), and this was matched by a reduction in the number of ED1-positive macrophages infiltrating the glomeruli. Interestingly, the injection of IL-4-expressing macrophages into single kidney produced a marked reduction in the numbers of ED1-positive macrophages in the contralateral noninjected kidney, an effect that could not be mimicked by systemic delivery of IL-4-expressing macrophages. This implies that the presence of IL-4-expressing macrophages in a single kidney can alter the systemic development of the inflammatory response. Macrophage transfection and delivery provide a valuable system to study and modulate inflammatory disease and highlight the feasibility of macrophage-based gene therapy.

Replace fine needle aspiration cytology with automated core biopsy in the triple assessment of breast cancer

All patients presenting with a symptomatic breast lump are assessed by means of triple assessment (clinical examination, radiology in the form of mammography and cytology by means of a fine needle aspiration) performed by the clinician in the rapid access breast clinic at the Royal Gwent Hospital, Newport, UK. In our initial experience, it was found that a significant number of patients were returning to clinic for the results of the triple assessment to find that the cytology was not conclusive and hence needed a core biopsy, thus delaying diagnosis and definitive treatment. Therefore, a prospective study was carried out over a 6-month period, where all patients presenting with a symptomatic lump with a clinical or radiological suspicion of breast cancer had, in addition to the standard triple assessment, an automated core biopsy, thus giving rise to the quadruple assessment of the breast lump. A total of 52 patients with a clinical or radiological suspicion of breast cancer were included over this 6-month period. Of these 52 patients, 31 had a definitive diagnosis of breast cancer on fine needle aspiration (sensitivity 60%) compared with 50 of the 52 patients on core biopsy (sensitivity 96%). When radiology was diagnostic of breast cancer (R 5), the sensitivity of cytology was 61% compared with 97% with core biopsy. However, when radiology was not diagnostic of cancer (R 1-4), the sensitivity of cytology fell to 53% while the sensitivity of core biopsy remained high at 95%. The overall cellularity rate for cytology was 96%, which exceeds the BASO requirement for fine needle aspiration cytology. From these results, we conclude that automated core biopsy has a superior diagnostic power when compared with fine needle aspiration cytology and hence should replace fine needle aspiration cytology in the assessment of symptomatic breast lumps.

"Whole body" mobility after one year of intraoral appliance therapy in children with cerebral palsy and moderate eating impairment

The reciprocal influence of body postures on the oral structures, but also of the oral structures on body postures, has been proposed by clinicians and is taken into consideration when treating children with poor postural control and moderate to severe eating impairments. However, this relationship has not been rigorously investigated. The purpose of this study was to document the possible relationships among oral-motor, postural, and ambulatory control. Ambulatory skills [exclusive use of wheelchair (w/c) vs w/c and ambulation], postural control when sitting, "pathologic" reflexes, and lip and tongue posture were recorded before and after one year of therapy with an intraoral appliance (ISMAR) in 20 children with cerebral palsy and moderate eating impairment. Significant improvement occurred in sitting (head-trunk-foot control) following one year of ISMAR therapy. Ambulatory status also significantly improved above the level of maturation. Half of the children showed marked improvement in oral posture, i.e., their resting mouth posture was closed rather than open. These results support an hypothesis of interaction between oral structures and postural control of the "whole body." Further studies are needed to determine the controls of such a relationship.

Relationship of psychosis to aggression, apathy and function in dementia

BACKGROUND

Psychosis has been associated with aggression in dementia, but the nature of this relationship has been unclear. There has been very little research into the relations between apathy and functional status to psychosis in dementia. The purpose of this study is to investigate the relationship between psychosis and aggression, apathy, and functional status in outpatients with dementia.

METHODS

The presence of psychosis was assessed by clinical interview and two scales: the Neuropsychiatric Inventory and the Columbia University Scale for Psychopathology in Alzheimer's Disease. The maximum likelihood estimation technique was used to determine the best estimate of the presence of psychosis. Aggression, apathy, and functional status (activities of daily living: ADLs) were measured using structured instruments.

RESULTS

Sixty-one subjects were included. The CUSPAD and NPI provided low false positive and negative rates. ANCOVA analyses showed that psychosis was significantly associated with aggression, even when controlling for apathy, depression, and ADLs. Psychosis was related to apathy only when depression was controlled for. Hallucinations were related to impaired basic ADLs, even when depression and apathy were controlled for.

CONCLUSIONS

Relationships were found between psychotic symptoms in dementia and aggression as well as apathy and impaired functional status. These relationships suggest pathophysiologic mechanisms and have possible treatment implications.

Large-dose oral dextromethorphan as an adjunct to patient-controlled analgesia with morphine after knee surgery

Dextromethorphan is a weak N-methyl-d-aspartate (NMDA) receptor antagonist that inhibits spinal cord sensitization in animal models of pain and also inhibits the development of cutaneous secondary hyperalgesia after tissue trauma. Perhaps coadministration of an NMDA antagonist with an opioid would lead to better pain relief, particularly with movement and an opioid-sparing effect. This has been shown for ketamine, but previous studies with dextromethorphan that have used small doses have shown only a modest reduction in morphine requirements with no or minimal changes in the postoperative pain experience. We sought to determine whether a large dose of this drug, just below the maximum tolerated dose, could potentiate morphine analgesia while simultaneously causing a significant improvement in the management of the postoperative pain experience. Sixty-six patients undergoing knee surgery were enrolled in the study. The study design was a prospective, randomized double-blinded comparison with placebo of 200 mg of dextromethorphan given eight hourly. Postoperative pain experiences were assessed by postoperative morphine usage. Visual analog and verbal rating scales were used to assess pain with movement as well as side effects. Dextromethorphan treatment led to a significant but modest reduction in morphine requirements (29.3% P < 0.05) but no reduction in postoperative pain levels. We conclude that increasing orally administered dextromethorphan to near maximum tolerated doses does not provide greater morphine sparing than 20-40 mg given 6-8 hourly as in previous studies. Furthermore we conclude that dextromethorphan does not improve pain scores in a manner expected of a drug with NMDA antagonist properties.