Methylmalonic aciduria and propionic acidaemia studied by proton nuclear magnetic resonance spectroscopy

Proton nuclear magnetic resonance spectroscopy has been used to monitor changes in urinary metabolites in a patient with propionic acidaemia over a period of 10 months and in a patient with methylmalonic aciduria over a period of 11 days. Results could be obtained within 5-10 min of sample receipt. In the spectra on the patient with propionic acidaemia not only could fluctuations in 3-hydroxypropionate and propionylglycine excretion be followed, but also variations in creatine, glycine and betaine, which were often present at millimolar concentrations. The patient with methylmalonic aciduria had an acute episode of severe ketoacidosis during which the glycine excretion fell but creatine excretion rose and then fell on recovery from the episode. The changes in the creatine excretion may reflect disorders in intracellular energy supply. Nuclear magnetic resonance is a powerful technique for monitoring metabolic perturbations in the organic acidurias in 'real-time', allowing the planning and evaluation of therapy.     

Expandable metal stents for tracheal obstruction: permanent or temporary? A cautionary tale.

An expandable metal stent inserted via a long term tracheostomy successfully relieved life threatening respiratory obstruction due to benign tracheal stenosis. Later the patient's tracheostomy suction catheter became stuck on the stent and dislodged it. The stent was removed electively, without damaging the trachea, with a rigid biopsy forceps.     

Selective sequestration of X4 isolates by human genital epithelial cells: Implication for virus tropism selection process during sexual transmission of HIV

X4 and R5 HIV strains are present in the semen of men infected with HIV but R5 isolates are transmitted preferentially. The role of human epithelial cells in this selection is addressed. Three human cervical cell lines-CaSki, SiHa, and HEC1A-and normal human vaginal cells from HIV-negative donors were characterized for HIV receptor expression and incubated with X4 and R5 laboratory-adapted strains or primary isolates. The infection was assessed by detection of intracellular HIV DNA. The three cell lines were shown to express on their surface the CXCR4 and GalCer molecules, but not the CD4 and CCR5 ones. The three cell lines and normal human vaginal cells were found to be selectively permissive to X4 HIV entry; the preincubation of the cell lines with rhSDF-1 inhibited this infection. The detection of the intracellular proviral DNA in the cell lines and in normal human vaginal cells demonstrated a selective integration of X4 strains. Additional experiments showed that no extracellular RNA was detected in the supernatants of HEC1A cells infected by X4 isolates either after 18 days of culture or after incubation with PHA-stimulated PBMCs and that no transmission occurred after co-culture between infected HEC1A cells and PHA-stimulated PBMCs. These results suggest specific sequestration of X4 strains by genital epithelial cells, which could explain, at least in part, the HIV tropism selection process during sexual intercourse.     

Serum C-reactive protein concentrations in patients with pulmonary sarcoidosis.

In a prospective study serum C-reactive protein concentrations were measured in nine patients with "active" pulmonary sarcoidosis (as assessed by bronchoalveolar lavage lymphocyte counts, gallium-67 lung scanning, and serial pulmonary function testing), and in five patients with "inactive" disease. Active pulmonary sarcoidosis was associated either with no rise or with only a modest rise in serum C-reactive protein concentrations. In contrast, serum C-reactive protein concentrations in 12 patients with sputum positive pulmonary tuberculosis were considerably raised. Serum C-reactive protein may thus provide a valuable test in the differentiation of sarcoidosis from conditions which it may mimic and which are known to induce an acute phase response.     

Indicators of free radical activity in patients developing radiation pneumonitis

PURPOSE: Radiation pneumonitis is thought to occur as the result of excess free radical generation following radiotherapy. Various in vitro studies have shown that large doses of irradiation can cause membrane lipid peroxidation and the oxidation of protein sulphuryl groups. We, therefore, studied two circulating markers of lipid peroxidation and an indicator of "catalytic iron" (potentially available iron to catalyze the generation of free radicals) in patients undergoing radiotherapy. METHODS AND MATERIALS: The 9,11 diene conjugate of 9,12 linoleic acid, expressed as their molar ratio (percentage molar ratio (MR)) and thiobarbituric acid reactive acid-substances (TBARS), as well as levels of circulating desferrioxamine-chelatable iron assay, were assayed. Serial blood samples were taken over a 3-month period in 25 patients with inoperable nonsmall cell lung cancer. RESULTS: Ten patients developed radiation pneumonitis. The patients who developed pneumonitis showed a tendency for the serum percentage molar ratio to increase after a week. The change in the percentage molar ratio between Time 0 and 1 week of radiotherapy was significantly higher in the group that subsequently developed pneumonitis compared to the group that did not (p = 0.002). The initial serum TBARS levels in patients were not significantly elevated compared to controls and there was no difference in the serum TBARS levels in the pneumonitis and nonpneumonitis groups throughout the study period. After 1 week of radiotherapy the group that subsequently developed pneumonitis had a significantly higher level of desferrioxamine-chelatable iron (DFx-iron) compared with the nonpneumonitis group (p = 0.05). CONCLUSION: These data suggest that both the percentage MR and DFx-iron appear to reflect an increased susceptibility to develop radiation pneumonitis and after 1 week of radiotherapy they indicate patients who are likely to subsequently develop pneumonitis. Hence, these indicators could indicate the group of patients that could benefit from intervention therapies with antioxidants.     

Accuracy of diagnostic coding of hospital admissions for cryptogenic fibrosing alveolitis.

To determine the accuracy of diagnostic coding of cryptogenic fibrosing alveolitis, the case notes of 166 admissions to four hospitals were reviewed. These consisted of all admissions that had been coded as "idiopathic fibrosing alveolitis" (ICD code 516.3: 97 admissions) or as "postinflammatory pulmonary fibrosis" (ICD code 515.9: 69 admissions). Of 88 available records of admissions coded as idiopathic fibrosing alveolitis, 70 (80%) patients had definite cryptogenic fibrosing alveolitis, and six (7%) possible cryptogenic fibrosing alveolitis according to predetermined conventional clinical criteria. Only seven (8%) admissions were clearly coded wrongly. Sixty four records were available for patients coded as having postinflammatory pulmonary fibrosis; 16 (25%) of these patients had definite cryptogenic fibrosing alveolitis, a further 12 (19%) had possible cryptogenic fibrosing alveolitis or fibrosing alveolitis with a connective tissue disorder, and the remainder had a very wide range of diagnoses. In this study the idiopathic fibrosing alveolitis (ICD 516.3) code was relatively reliable, but a substantial proportion of admissions coded under postinflammatory pulmonary fibrosis (ICD 515.9) also had cryptogenic fibrosing alveolitis and code 515.9 was of little diagnostic value. The data are inadequate for case finding, though in respect of cryptogenic fibrosing alveolitis may be adequate for planning purposes. There continues to be a need for more medical input into the process of diagnostic coding.     

Future ophthalmology practice pattern: A survey of Saudi Board of Ophthalmology residents

Purpose

The main purpose of the study was to examine and identify factors that influence the future practice pattern of Saudi Board of Ophthalmology residents as well as their academic goals. This study also aimed to compare the plans and career goals of the current Saudi ophthalmology residents with a former cohort of Saudi ophthalmology residents.

Platelet toll-like receptors are crucial sensors of infectious danger moieties

In addition to their haemostatic role and function in the repair of damaged vascular epithelium, platelets play a defensive role in innate immunity, having the capacity to produce and secrete various anti-infectious factors, as well as cytokines, chemokines and related products, to interact with other immune cells to modulate immune responses to pathogens. Thus, it is now widely acknowledged that platelets participate in inflammatory processes and infection resolution, most notably by expressing and using receptors to bind infectious pathogen moieties and contributing to pathogen clearance. The ability of platelets to sense external danger signals relates to the expression of certain innate immunity receptors, such as toll-like receptors (TLRs), and the activation of efficient cell signalling machinery. TLR engagement triggers platelet response, which results in adapted degranulation according to: the type of TLR engaged, the nature of the ligand and the milieu; together, the TLR-mediated event and other signalling events may be followed by aggregation. Platelets thus use complex tools to mediate a whole range of functions upon sensing danger. By linking the inflammatory and haemostatic platelet response to infection, TLRs play a central role. The extent of the inflammatory response to pathogen clearance is still a debatable issue and is discussed in this short review.