Profile of inborn errors of metabolism in a tertiary care centre PICU

Objective  

To study the clinico-investigative profile and outcome of patients with inborn errors of metabolism (IEM) presenting to the pediatric intensive care unit (PICU).     

Glucocorticoid deficiency increases phospholipase A2 activity in rats.

An important mechanism for the antiinflammatory effect of pharmacological doses of glucocorticoids is the inhibition of arachidonic acid release from phospholipids by phospholipase A2 (PLA2). As a corollary, one might predict that low endogenous concentrations of glucocorticoids favor inflammatory disease states. Indeed, clinical and experimental observations revealed an association between glucocorticoid deficiency and disease states caused by immunological and/or inflammatory mechanisms. The purpose of the present investigation was to study the regulation of PLA2 mRNA, protein, and enzyme activity in adrenalectomized (ADX) rats where glucocorticoid concentrations were below physiological levels. The mRNA of group I and II PLA2 were measured by PCR. Group II PLA2 mRNA was increased by 126 +/- 9% in lung tissue of ADX rats, whereas group I PLA2 was increased only by 27 +/- 1.5%. The increase in group II mRNA in ADX rats was reflected by a corresponding increase of group II PLA2 protein (70-100%) in lung, spleen, liver, and kidney. This increase was reversed by the administration of exogenous corticosterone. After ADX, the percentage increase in total PLA2 activity was higher than that of mRNA or PLA2 protein, suggesting that the activity of the enzyme was modulated by inhibitors or activators. The concentration of lipocortin-I, an inhibitor of PLA2 enzyme was strongly correlated with the activity of PLA2 in the tissues (lung, spleen, liver, and kidney). In all these tissues, the concentrations of lipocortin-I declined after ADX. Thus upregulation of PLA2 enzyme and downregulation of lipocortin-I might account for the enhanced inflammatory response in hypoglucocorticoid states.     

Nitric oxide regulation of L-arginine uptake in murine and human macrophages

L-arginine uptake systems in macrophages play a role in regulating nitric oxide synthesis via the inducible L-arginine nitric oxide pathway. This paper describes the association of L-arginine transport with nitric oxide production in human peripheral blood monocyte-derived macrophages and in peritoneal macrophages from control and inducible nitric oxide synthase knock out C57BL6 mice. Experiments performed with human macrophages suggested that little or no nitric oxide was produced in human macrophages in vitro and that human macrophages exhibit a different arginine transport-specific response to stimuli compared with rodent macrophages. We conclude that increased L-arginine transport in both human and murine macrophages is dependent on the requirement for intracellular nitric oxide.     

Opinions and practices of blood glucose control in critically ill patients with pre-existing type 2 diabetes in Australian and New Zealand intensive care units

BackgroundApproximately 9000 patients with type-2 diabetes mellitus (T2DM) are admitted to an intensive care unit (ICU) in Australia and New Zealand annually. For these patients, recent exploratory data suggest that targeting a more liberal blood glucose range during ICU admission may be safe and potentially beneficial. However, the current approach to blood glucose management of patients with T2DM in Australia and New Zealand ICUs is not well described, and there is uncertainty about clinician equipoise for trials of liberal glycaemic control in these patients.AimThe aim is to describe self-reported blood glucose management in patients with T2DM by intensivists working in Australian and New Zealand ICUs and to establish whether equipoise exists for a trial of liberal versus standard glycaemic control in such patients.MethodAn online questionnaire of Australia and New Zealand intensivists conducted in July–September 2016.ResultsSeventy-one intensivists responded. Forty-five (63%) used a basic nomogram to titrate insulin. Sixty-six (93%) reported that insulin was commenced at blood glucose concentrations >10 mmol/L and titrated to achieve a blood glucose concentration between 6.0 and 10.0 mmol/L. A majority of respondents (75%) indicated that there was insufficient evidence to define optimal blood glucose targets in patients with T2DM, and 59 (83%) were prepared to enrol such patients in a clinical trial to evaluate a more liberal approach.ConclusionA majority of respondents were uncertain about the optimal blood glucose target range for patients with T2DM and would enrol such patients in a comparative trial of conventional versus liberal blood glucose control.     

Is rheumatoid factor still a superior test for the diagnosis of rheumatoid arthritis?

The diagnosis of rheumatoid arthritis (RA) is based primarily on the 1987 revised American College of Rheumatology criteria for RA, which considers mainly the clinical symptoms. But typical clinical symptoms of RA are not manifested completely in early disease course. On the other hand, appreciable advantages have been made in the therapeutic strategy of RA in the last decade and highly effective disease-modifying anti-rheumatic drugs are available now for the control of RA. The treatment strategy for the control of early RA is aggressive. Thus, a highly specific and early diagnostic marker is needed for the detection of RA. Our study is an attempt to see the role of anti-CCP2 antibody (claimed to be highly specific and early diagnostic tool) in the diagnosis of RA. We studied 119 cases of RA in terms of clinical symptoms, disease duration and various autoantibody [including rheumatoid factor (RF), anti-CCP2 antibody, antinuclear antibody, anti-dsDNA] and C-reactive protein status. All the tests were also performed in 26 age and sex-matched healthy controls. Estimation of antibodies was done by quantitative ELISA. IgM RF was positive in 47.89% cases (p value = 0.000), followed by IgG RF (42.01%, p = 0.000) and IgA RF (36.97%, p = 0.000). RF was positive in 64.7% RA cases (p value = 0.000) when all three isotypes were tested together. RF was also detected in one healthy control. In 92 cases, anti-CCP2 Ab was done, hence other data were analyzed further in 92 cases only. Anti-CCP2 Ab was positive (cut-off = 15.0 U/ml) in only 50% RA patients but none of the healthy controls was positive for it. Swelling of joints was seen in 82.6% anti-CCP2 Ab positive cases (p value = 0.092) when compared with anti-CCP2 Ab negative cases (67.4%) while among RF positive cases, only 65.4% ((p value = 0.010) cases had swelling of joints. Out of 39 RA cases presenting with disease duration less than 1 year, only 48.71% patients were anti-CCP2 Ab positive while RF was positive in 61.53% patients. Utility of various combined autoantibody tests revealed that if one does all isotypes of RF (IgG, IgA and IgM) only, then 64.7% RA cases can be diagnosed and if anti-CCP2 Ab is added to it, the sensitivity increases to 75.56%. Thus, our study concludes that anti-CCP2 Ab is not a sensitive test for the diagnosis of RA neither it is useful in early diagnosis of RA, but it increases the sensitivity if added with all RF isotypes.     

Anti-coagulant activity of a metalloprotease: further characterization from the Indian cobra (<Emphasis Type="Italic">Naja naja</Emphasis>) venom

A high molecular mass, non toxic metalloprotease the NN-PF3 with the bound Ca²⁺ and Zn²⁺ from the Naja naja venom has been studied further for its anticoagulant property. The molecular mass by MALDI-TOF mass spectrometry was 67.81 kDa. The NN-PF3 exhibited fibrin(ogen)olytic activity. In addition to fibrinogen, NN-PF3 hydrolyzed blood and plasma clot with the later hydrolyzed about one fold higher. The α polymer of fibrin was preferentially hydrolyzed over the α chain but the β chain and γ–γ dimer remained untouched. It was devoid of plasminogen activation property. It prolonged the activated partial thromboplastin time, prothrombin time and the thrombin clotting time of citrated human plasma. It did not affect the thrombin activity. In mice, defibrinogentaion, prolonged bleeding time (P < 0.01) and reduced fibrinogen level were observed following intravenous injection. Human plasma or α2-macroglobulin did not, but the polyvalent anti-venom inhibited the NN-PF3 activity. In contrast to most snake venom metalloproteases, it did not degrade extra cellular matrix proteins.     

An experience with 1000 consecutive cystic duct ligation in laparoscopic cholecystectomy

Although rare, the clips are known to slip, dislodge, ulcerate, migrate, internalize, embolize, and give rise to necrosis of the cystic duct with resultant bile leak and other complications. Ligation of cystic duct has been practiced since long time with several modifications of intracorporeal and extracorporeal techniques. We have used a standard 'C' technique of intracorporeal knotting of cystic duct in 1000 consecutive patients of laparoscopic cholecystectomy. There was no case of bile leak in cystic duct ligation and no other related complications. The mean time taken for the cystic duct ligation was 3.5 minutes. This technique of total intracorporeal cystic duct and artery ligation in laparoscopic cholecystectomy is simple, secure, and economical.     

Influence of surgical technique on axillary seroma formation: a randomized study

The aim of this study was to evaluate the influence of surgical technique in the form of electrocautery and suction drains on seroma formation following surgery for breast cancer. A prospective randomized study was carried out. One hundred and sixty patients with breast cancer who underwent surgery were allocated to four arms using a 2 x 2 factorial design. This method enabled us to evaluate the independent effect of two different causative factors on the incidence of postoperative seroma formation using a single dataset with limited numbers. The main outcome measure was postoperative seroma formation defined as a postoperative axillary collection requiring more than one aspiration after removal of the drain. The incidence of seroma in our institution is 90%. Incidence of postoperative seroma was 88.3% if electrocautery was used, which reduced to 82.2% if surgery was carried out using scissors for dissection and ligatures for haemostasis (P = 0.358). There was no influence on the incidence of seroma formation whether suction drain (84.6%) or corrugated drains (86.1%) were used (P = 0.822). The use of electrocautery in axillary dissection does not adversely affect postoperative seroma formation after surgery for breast cancer. The use of different drainage techniques has no bearing on the postoperative seroma formation. The surgical technique has no influence on the rate of seroma formation after surgery for breast cancer.     

PLA2 mediated arachidonate free radicals: PLA2 inhibition and neutralization of free radicals by anti-oxidants--a new role as anti-inflammatory molecule

PLA2 enzyme catalyses the hydrolysis of cellular phospholipids at the sn-2 position to liberate arachidonic acid and lysophospholipid to generate a family of pro-inflammatory eicosanoids and platelet activating factor. The generation of pro-inflammatory eicosanoids involves a series of free radical intermediates with simultaneous release of reactive oxygen species (superoxide and hydroxyl radicals). Reactive oxygen species formed during arachidonic acid metabolism generates lipid peroxides and the cytotoxic products such as 4-hydroxy nonenal and acrolein, which induces cellular damage. Thus PLA2 catalyzes the rate-limiting step in the production of pro-inflammatory eicosanoids and free radicals. These peroxides and reactive oxygen species in turn activates PLA2 enzyme and further attenuates the inflammatory process. Therefore scavenging these free radicals and inhibition of PLA2 enzyme simultaneously by a single molecule such as antioxidants is of great therapeutic relevance for the development of anti-inflammatory molecules. PLA2 enzymes have been classified into calcium dependent cPLA2 and sPLA2 and calcium independent iPLA2 forms. In several inflammatory diseases sPLA2 group IIA is the most abundant isoform identified. This isoform is therefore targeted for the development of anti-inflammatory molecules. Many secondary metabolites from plants and marine sponges exhibit both anti-inflammatory and antioxidant properties. Some of them include flavonoids, terpenes and alkaloids. But in terms of PLA2 inhibition and antioxidant activity, the structural aspects of flavonoids are well studied rather than terpenes and alkaloids. In this line, molecules having both anti-oxidant and PLA2 inhibitions are reviewed. A single molecule with dual activities may prove to be a powerful anti-inflammatory drug.