Oesophagopleural fistula as a novel cause of failed non-invasive ventilation

Non-invasive ventilatory support is commonly used to palliate symptoms and extend longevity in patients with ventilatory failure due to neuromuscular and restrictive chest wall disease. We describe a patient with ventilatory failure due to a combination of these factors in whom the application of non-invasive ventilation led to intolerable symptoms. An unusual cause for this was found.

Cystic fibrosis-related diabetes: the role of peripheral insulin resistance and beta-cell dysfunction

AIMS

The goal of this study was to identify the glycaemic status and investigate the roles of peripheral insulin resistance (IR) and pancreatic -cell dysfunction in the pathogenesis of cystic fibrosis-related diabetes (CFRD) in adult cystic fibrosis (CF) patients with no previous history of glycaemic disturbances.

METHODS

The glucose tolerance status of 68 CF patients was determined using 2-h oral glucose tolerance tests (OGTTs). Peripheral IR was measured using the homeostasis model assessment for insulin resistance (HOMA-IR) in the CF group and 46 normal healthy control subjects. Pancreatic -cell function, calculated as the ratio between the 30-min increment in plasma insulin and the corresponding 30-min post-OGTT plasma glucose concentration, was also measured in a subset of 30 CF patients and 16 normal healthy controls. Extended 180-min OGTTs, with frequent plasma glucose and insulin sampling, were also undertaken in 24 CF patients and eight normal healthy controls to determine glucose-induced insulin response.

RESULTS

Of the 68 CF patients studied, 41, 18 and nine were found to have normal, impaired and diabetic glucose tolerances, respectively. The mean HOMA-IR values (mU/mmol) in the CF patients, as a whole, were not significantly different compared with the normal healthy controls (CF 2.2 +/- 1.1 vs. control 1.8 +/- 0.9; NS). Within the CF group, glycaemic status had no impact on HOMA-IR (mU/mmol): 2.2 +/- 1.2 (normal glucose tolerance); 2.0 +/- 1.0 (impaired glucose tolerance); and 2.3 +/- 1.1 (diabetic glucose tolerance). -cell function (mU/mmol) was not only significantly lower in the CF group (CF 1.65 +/- 1.8; P < 0.001) but also in the CF group with normal glucose tolerance (2.25 +/- 2.10; P < 0.01) compared with healthy control (4.98 +/- 2.38). Mean plasma glucose concentrations were generally higher and mean plasma insulin concentrations lower in the CF group as a whole when compared with normal healthy controls. Within the CF group, there was a progressive decline in glucose-induced insulin release with worsening glycaemic status.

CONCLUSIONS

A lack of difference in peripheral IR, measured using HOMA-IR, in the CF group and healthy controls or within the CF group with differing glycaemic status suggests that IR does not have a significant role in the pathogenesis of CFRD. Pancreatic -cell function, already subnormal in CF patients with OGTT-defined normal glucose tolerance status, deteriorated further with worsening glycaemic status. This suggests that insulinopenia plays a prominent role in the pathogenesis of glucose intolerance and subsequent development of CFRD.

Diagnosis of cystic fibrosis related diabetes: a selective approach in performing the oral glucose tolerance test based on a combination of clinical and biochemical criteria

BACKGROUND

Cystic fibrosis related diabetes (CFRD) has become increasingly common with the increasing longevity of patients with cystic fibrosis. The diagnosis of CFRD is important as its development may lead to a clinical deterioration which may be reversed with treatment. The oral glucose tolerance test (OGTT) is the method of choice in the diagnosis of CFRD, but performing OGTTs on all patients is inconvenient for patients and labour intensive for staff. The aim of this study was to identify a more selective approach in performing OGTTs in the diagnosis of CFRD based on the use of a combination of clinical and biochemical criteria.

METHODS

Clinically stable adult patients with cystic fibrosis not known to be diabetic attending the Royal Brompton Hospital Cystic Fibrosis Clinic for their annual review were invited to return within a month to have an OGTT. The result of the OGTT was compared with the results of tests performed during the annual review. The sensitivities and specificities of various methods used in the screening or diagnosis of CFRD were determined using OGTT as the "gold standard" diagnostic method. The combination of clinical and biochemical criteria which resulted in the highest sensitivity and specificity in the diagnosis of CFRD was determined.

RESULTS

Between August 1996 and May 1997 122 patients became eligible for the study, 91 of whom agreed to take part. The number of patients with normal, impaired, and diabetic glucose tolerance was 58 (64%), 21 (23%), and 12 (13%), respectively. When used alone, abnormal glycosylated haemoglobin (HbA1c) was found to have the highest sensitivity (83%; 95% CI 62 to 100) in the diagnosis of CFRD. The combination of an abnormal random blood glucose and/or abnormal HbA1c and/or symptoms of hyperglycaemia or weight loss was found to have the highest sensitivity (92%; 95% CI 76 to 100) in the diagnosis of CFRD. The specificity of this combination in the diagnosis of CFRD was 79% (95% CI 70 to 88). By selectively performing OGTTs in patients with one or more of the criteria cited above, 11 of the 12 patients with OGTT defined diabetes would have been identified.

CONCLUSIONS

Patients with cystic fibrosis already have to undergo a large number of routine investigations. The selective approach in performing OGTTs described here has the potential to identify the majority of patients with CFRD without the need to perform this investigation on all patients. This approach is likely to be welcomed by patients and will lead to significant savings in terms of time and resources for patients and staff. Further larger studies are warranted to validate this selective approach in the diagnosis of CFRD.

Circulating immunoreactive interleukin-6 in cystic fibrosis

We measured circulating and sputum-sol concentrations of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), neutrophil elastase-alpha1-antiproteinase complex (NEAPC), and C-reactive protein (CRP) in an exacerbation, after antibiotic treatment, and in clinically stable patients with cystic fibrosis and chronic pulmonary infection with Pseudomonas aeruginosa. The aim was to determine the compartmental patterns of a proinflammatory and anti-inflammatory cytokine compared with other markers of inflammatory activity in cystic fibrosis. IL-6, NEAPC, CRP, and absolute neutrophil count were reduced after antibiotic treatment, p < 0.01. IL-6 and CRP concentrations were greater, p = 0.007, and p = 0.01, respectively, in a stable group of patients compared with those at the end of an exacerbation. IL-6 and CRP concentrations were related (r = 0.836, p < 0.0001), and both were greater than in matched control subjects (p < 0.001) at all times studied. Sputum-sol concentrations of IL-6 after treatment were positively related to FEV1 and FVC and inversely related to concentrations of neutrophil elastase. The separation between patients and healthy subjects, and the reduction of IL-6 after antibiotic treatment indicates it could be used as a marker of inflammation, but its relationship to other markers depends on the compartment in which it is measured.

Thromboembolism related to a Port-a-Cath device in a patient with cystic fibrosis

The case is described of a potentially life threatening complication relating to the use of a totally implantable venous access device (Port-a-Cath) in a 28 year old patient with cystic fibrosis. The device was inserted in 1990 and used repeatedly for antibiotic therapy without any complications. In 1995, during assessment for double lung transplantation, a 3 cm thrombus was found at the tip of the catheter in the right atrium. Embolisation of the thrombus to the pulmonary arteries occurred after the infusion of recombinant tissue plasminogen activator (rt-PA). Thrombus formation may be associated with totally implantable venous access devices and thromboembolism may occur following the use of thrombolytic agents in the treatment of such thrombosis.

Totally implantable venous access devices in adult patients with cystic fibrosis

Between September 1987 and April 1995, 33 totally implantable venous access devices (TIVADs) were implanted at the Cardiff Adult Cystic Fibrosis Centre, U.K., for the purpose of intermittent antibiotic therapy, including 22 PORT-A-CATH (Simcare Ltd.) devices (PCs) to 18 patients, and 11 P.A.S.PORT (Simcare Ltd.) devices (PPs) to nine patients. There were 50 complications during 25 824 days of catheter function which were severe enough to lead to removal of the devices in eight patients (six PCs and four PPs). Overall, patients' acceptance of these devices was excellent. Despite a shorter functional time and a higher rate of complications in PPs compared with PCs, PPs were preferred by many patients for cosmetic reasons. Totally implantable venous access devices provide safe, effective and convenient means of venous access in cystic fibrosis patients requiring intermittent antibiotic therapy.

Gender influences sphincter of Oddi response to cholecystokinin in the prairie dog

Although gallstones and disorders of biliary tract motility are both more common in women than men, sphincter of Oddi motility has not previously been compared between the sexes. In this study, cholescintigraphy (under ketamine and diazepam anesthesia) was used to determine gallbladder emptying rate and ejection fraction in response to cholecystokinin (CCK) in eight male and six female prairie dogs fed a nonlithogenic diet. Ten days later, under alpha-chloralose anesthesia, sphincter of Oddi phasic wave activity was monitored for 10-min intervals before (control), during 20 min of CCK infusion, and for 20 min after infusion. Gallbladder emptying rate and ejection fraction and baseline sphincter of Oddi frequency, amplitude, and motility index (= frequency x amplitude) did not differ significantly between the sexes. Sphincter of Oddi phasic wave frequency was increased during CCK infusion in both males and females, but the change in amplitude was significantly greater in females, than males. We conclude that the increased incidence of biliary tract disease in women may be due to altered sphincter of Oddi hormonal response.

A bronchial butterfly

We report on an asthmatic patient who accidentally inhaled the small metal backing ("butterfly") of a nose stud, which she wore daily. Despite administration of nebulized salbutamol, postural drainage, and the use of rigid and fibreoptic bronchoscopes, attempted removal of the butterfly remained unsuccessful. Spontaneous expulsion of the butterfly occurred two months following inhalation. We suggest that consideration should be given by nose stud jewelry manufacturers to a more secure fixing device.

A bronchial butterfly

We report on an asthmatic patient who accidentally inhaled the small metal backing ("butterfly") of a nose stud, which she wore daily. Despite administration of nebulized salbutamol, postural drainage, and the use of rigid and fibreoptic bronchoscopes, attempted removal of the butterfly remained unsuccessful. Spontaneous expulsion of the butterfly occurred two months following inhalation. We suggest that consideration should be given by nose stud jewelry manufacturers to a more secure fixing device.

In vivo imaging of baboon and human dopamine transporters by positron emission tomography using [11C]WIN 35,428

[11C]WIN 35,428 was evaluated as a specific in vivo radioligand for the dopamine transporter site by PET scanning in nonhuman primates and humans. In studies with a baboon (Papio anubis), [11C]WIN 35,428 accumulated in brain regions containing dopamine transporters, i.e., the striata. This accumulation was partially blocked by prior administration of (-)cocaine (4 mg/kg, i.v.). Placement of a unilateral lesion of dopamine-containing nerve terminals with MPTP resulted in a unilateral reduction in [11C]WIN 35,428 accumulation in the striatum on the side of the lesion. Imaging of D2 dopamine receptors with [11C]NMSP in the same MPTP-treated animals showed much less reduction in the postsynaptic D2 dopamine receptors as compared to the much larger reduction in the dopamine transporters labeled with [11C]WIN 35,428. A total of ten normal human volunteers (five males and five females) with ages ranging from 19 to 81 years were studied. The caudate/cerebellar and putamen/cerebellar ratios ranged from 4.4 to 5.7 90 min after injection of the tracer. Preliminary kinetic modeling with arterial plasma sampling resulted in an average binding potential (k3/k4) of 4.98 in the caudate nucleus and 5.13 in putamen. To demonstrate in vivo blockade with dopamine reuptake inhibitors, two subjects received prior oral doses of 6 mg mazindol. Subject 5 had significant reductions of 29% in the caudate/cerebellar ratio at 90 min, 35% in the putamen/cerebellar ratio at 90 min, 45% in the caudate k3/k4 ratio from 6.7 to 3.7, and 46% in the putamen k3/k4 from 4.7 to 2.5. Subject 8 had significant reductions of 20% in both the caudate/cerebellar ratio and the putamen/cerebellar ratio at 90 min. During the human PET studies, a number of neuropsychological tests and physiological measurements were performed. No significant changes were found after administration of the [11C]WIN 35,428 alone. Taken together, these data indicate that [11C]WIN 35,428 is a promising radioligand for future studies of neuropsychiatric disorders that involve the dopamine transporter site.

Psychology's role in the public health response to assaultive violence among young African-American men

African-American male adolescents face disproportionate risk for death or injury resulting from assaultive violence. This article presents a public health framework for examining the problem and developing interventions. A brief interdisciplinary review of research is provided on the nature and extent of the problem, its etiology, and current approaches to prevention. Attention is called to intra- and intergroup differences in patterns among White and ethnic minority youth and to specific theories and research about assaultive violence among young African-American men. Emerging imperatives in the search for solutions are identified, emphasizing the need for cultural sensitivity in the design of preventive interventions and an expanded role for psychologists in the public health response to this critical health problem.

Psychology's role in the public health response to assaultive violence among young African-American men

African-American male adolescents face disproportionate risk for death or injury resulting from assaultive violence. This article presents a public health framework for examining the problem and developing interventions. A brief interdisciplinary review of research is provided on the nature and extent of the problem, its etiology, and current approaches to prevention. Attention is called to intra- and intergroup differences in patterns among White and ethnic minority youth and to specific theories and research about assaultive violence among young African-American men. Emerging imperatives in the search for solutions are identified, emphasizing the need for cultural sensitivity in the design of preventive interventions and an expanded role for psychologists in the public health response to this critical health problem.

Topological distribution of bovine serum albumin in multilamellar and unilamellar liposomes

The topological distribution of bovine serum albumin (BSA) in multilamellar vesicles (MLV) and unilamellar vesicles (ULV) composed of 1,2-dimyristoyl-sn-glycero-3-phosphorylcholine (DML)/cholesterol (molar ratio, 3:1) was studied by ESR using hydrophobic spin-labelled lecithins and hydrophilic Tempocholine. A spin-labelled BSA was also prepared, characterized and used as a probe. Results with hydrophobic spin-labelled lecithin probes showed no significant phospholipid-albumin interaction, indicating the virtual absence of albumin from the phospholipid bilayer of MLV and ULV. Reduction with L-ascorbic acid showed that MLV contained about 50% and ULV 90% of spin-labelled albumin on the surface. The distribution of Tempocholine in MLV and ULV was similar to that of entrapped BSA. These findings were confirmed by results using liposomes treated with nickel which broadened the ESR spectra of probes on the surface of vesicles. This study and our previous work suggest that the immunoadjuvant effect of liposomes can be mediated by surface antigens and can be maximized by preferential surface distribution as in ULV-associated BSA.