OBJECTIVEParaoxonase (PON) exhibits esterase activity (PON-AREase) and lactonase activity (PON-HCTLase), which prevent LDL oxidation and detoxify homocysteine thiolactone (HCTL). The role of HCTL and PON-HCTLase as a risk factor for the microvascular complication in diabetic retinopathy at the level of vitreous has not been investigated.RESEARCH DESIGN AND METHODSUndiluted vitreous from patients with proliferative diabetic retinopathy (PDR) (n = 13) and macular hole (MH) (n = 8) was used to determine PON-HCTLase and PON-AREase activity spectrophotometrically. HCTL levels were detected by liquid chromatography–tandem mass spectrometry. In vitro studies were done in primary cultures of bovine retinal capillary endothelial cells (BRECs) to determine the dose- and time-dependent effect of HCTL and homocysteine (Hcys) on PON-HCTLase activity, as well as to determine mRNA expression of PON by RT-PCR.RESULTSA significant increase in HCTL and PON-HCTLase activity was observed in PDR compared with MH (P = 0.036, P = 0.001), with a significant positive correlation between them (r = 0.77, P = 0.03). The in vitro studies on BRECs showed a dose- and time-dependent increase in the PON-HCTLase activity and mRNA expression of PON2 when exposed to HCTL and Hcys.CONCLUSIONSThis is the first study showing elevated levels of vitreous HCTL and PON-HCTLase activity in PDR. These elevations are probably a protective effect to eliminate HCTL, which mediates endothelial cell dysfunction. Thus, vitreous levels of HCTL and PON activity can be markers of diabetic retinopathy. The bioinformatics analysis reveals that the structure and function of PON that can be modulated by hyperhomocysteinemia in PDR can affect the dual-enzyme activity of PON.
Aim To estimate the arylesterase activity of serum paraoxonase-1 (PON1-ARE), which is reported to have an antioxidant and antiatherogenic potential and to correlate with plasma homocysteine (Hcys) and plasma TBARS in young adult central retinal venous occlusion (CRVO) patients. Methods A case-control prospective study carried out in 10 CRVO patients (mean age 27 ± 5 years; 7 males, 3 females) and 20 healthy controls (mean age 29 ± 5 years; 15 males, 5 females). Results The CRVO patients showed a significantly lowered serum PON1-ARE activity (P ¼ 0.009) along with a significant increase in the levels of plasma Hcys (P ¼ 0.018) when compared to the control subjects. There was a negative correlation between serum PON1-ARE and plasma Hcys levels (P ¼ 0.058) as well as between PON1-ARE and plasma TBARS levels (P ¼ 0.001) in the CRVO patients. Conclusion This is the first report of lowered serum PON1-ARE level as a risk factor for CRVO (OR ¼ 1.108, CI ¼ 0.914, 1.314; P ¼ 0.296), which is found to correlate with oxidative stress.
Scorpion sting is one of the common paediatric toxicological problems encountered in southern India. This rural emergency often results in an autonomic storm causing peripheral circulatory failure and/or congestive cardiac failure, leading to pulmonary oedema. A rare case of scorpion sting envenoming in an 11-year-old boy that led to local cellulitis, dyspnoea and congestive heart failure is presented. This was followed by a persistent high-grade fever which lasted for more than 2 weeks and was complicated by fatal Staphylococcus aureus infective endocarditis and septic pulmonary embolism. Although infective endocarditis has been reported occasionally in adults following scorpion sting, this is the first case of infective endocarditis in a native valve in a child following scorpion sting. The literature is reviewed and the mechanisms for this association are discussed.
Six years old boy underwent elective inguinal exploration for left congenital hernia. Per-operatively, an elongated, purplish-red, fleshy band of tissue was found inside the sac, adherent to the upper pole of testis. Biopsy was taken and the wound closed. An MRI done after 4 weeks proved the origin of the band from spleen. Laparotomy and excision of the band was done. The histo-pathology of the specimen was reported as normal splenic tissue. The above features are consistent with a diagnosis of spleno -gonadal fusion (SGF).Keywords Spleno-gonadal fusion . MRI for spleno-gonadal fusion . Splenic tissue in the testis . Splenic anomalies Case ReportA 6 years old boy attended our OPD with complaints of a left inguino -scrotal swelling. The swelling was reducible and was present since 1 1/2 years of age. On initial examination the sac was felt along with the cord structures in the root of the scrotum. Both testes were descended and the external genetalia was normal. He was diagnosed to have left congenital hernia and underwent elective inguinal exploration. The sac was identified, separated from cord structures and opened. An elongated, purplish-red, fleshy band of tissue was found inside the sac, adherent to the upper pole of testis (Fig. 1). Further exploration through the internal ring revealed this tissue was found extending towards the left upper quadrant of the abdomen, trans-peritoneally. Some large vessels were seen on the surface of the band. A provisional diagnosis of spleno gonadal fusion was made. However, as the relative contribution of the vessels from the band to the vascularity of the testis could not be determined and a pre-operative consent for orchiectomy was not available, it was decided to takea biopsy from this tissue. A wedge biopsy was taken and the wound was closed. The histo-pathology of the biopsy specimen was reported as normal splenic tissue.An MRI scan was done (4 weeks after the initial surgery) to delineate the soft tissue & vascular anatomy. A long cord-like extension of splenic tissue was seen from the inferior pole of the spleen to the level of the left inguinal canal (Fig. 2). It was located just deep to the parietal wall and was anterior to the descending colon and the left ilio-psoas. The signal intensity of this cord of tissue was seen paralleling the spleen in all sequences. A thin vascular channel could also be traced from the splenic hilum into the cord of tissue, further confirming its origin from the spleen. The left testis was small in size and was closely apposed to the inferior end of this cord of splenic tissue at the level of the inguinal canal. The above features were consistent with a diagnosis of complete spleno-gonadal fusion (SGF). A dopplerultrasonogram was also done which showed the presence of good, independent vascular supply to the testis via the vessels in the cord structures.A mini -laparotomy and left inguinal exploration was carried out. The band was found arising from the inferior
This is the first report to show that there is no difference in glucose uptake in BRECs and BRPs on exposure to AGE-BSA.
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