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Biomedical subjects

S Gulati

Publications and source records attributed to S Gulati.

At least 55 records · Page 3Linked to original sources

Biotinidase deficiency--a treatable entity.

Biotinidase deficiency is a well recognised treatable cause of a wide spectrum of progressive neurological symptoms. Recent reports have stressed the need to screen children with early onset of seizures, encephalopathy, neurodevelopmental delay, skin rash and alopecia. Enzyme estimation remains the conclusive test. We present a patient with biotinidase deficiency suspected on the above clinical grounds and diagnosed on the basis of metabolic acidosis, raised blood lactate, ketonuria and positive dinitrophenylhydrazine (DNPH) test and confirmed on urinary organic acid profile. Supplementation with biotin resulted in marked clinical improvement and normalisation of metabolic parameters. Thus the clinician should be alert to simple clinical pointers which aid in early diagnosis of these disorders.

Amidohydrolases↗

Early versus late-onset idiopathic focal segmental glomerulosclerosis.

Glomerular diseases in children, although similar in histological appearance to those in adults, may have a better prognosis. There is much controversy regarding the prognostic factors in idiopathic focal segmental glomerulosclerosis (FSGS), especially the comparative prognosis of children and adults. A comparative analysis was carried out of 36 consecutive biopsy-proven cases of idiopathic FSGS presenting early in life ['early onset' as seen in children < or =12 years (group I)] and 36 cases presenting later ['late-onset' as seen in older children >12 years and adults (group II)]. Patients were compared for clinical, biochemical, and histopathological features, as well as disease outcome. A significantly higher prevalence of hypertension (P=0.002) and microscopic hematuria was seen in group II (P=0.02). There were no differences between the two groups in glomerular filtration rates corrected for body surface area at initial presentation (92+/-11 ml/min/1.73 m2 vs. 94+/-14 ml/min/1.73 m2). Patients with 'late-onset' FSGS had a significantly higher number of glomeruli with segmental sclerosis (P=0.007), more mesangial matrix expansion (P=0.009), greater mesangial cellularity (P=0.003), and significantly higher blood vessel involvement (P=0.03) than those with 'early onset' FSGS. There was a significantly higher response to steroids in group I (82.3%) than group II (36.4%) (P<0.02). At the end of the study period, 2 patients in group I and 11 in group II had developed persistent renal failure (P=0.01). Thus 'early onset' FSGS is more common in males, has significantly lower prevalence of hypertension and microscopic hematuria, with less-severe histopathological involvement, is more often steroid responsive, and has a better prognosis than 'late-onset' FSGS.

Adolescent↗

Evaluation and long-term outcome of pediatric renovascular hypertension.

Seventeen children with renovascular hypertension were managed at the Royal Children's Hospital, Melbourne, over the 20-year period from 1975 to 1996. The age at presentation ranged from 10 days to 18 years. All children presented with severe hypertension with mean systolic blood pressure 7 standard deviations above age-matched averages and mean diastolic blood pressure 5.5 standard deviations above age-matched averages. Neurofibromatosis was the most common etiology (58% of patients) and there were no cases of Takayasu's arteritis. Patients underwent a variety of biochemical and imaging investigations but in all cases renal angiography was necessary for definitive diagnosis and for planning therapy. Ten of the 17 patients had surgical procedures performed. Percutaneous transluminal angioplasty was performed in four patients but led to cure in only one patient following thrombosis of the affected artery producing segmental renal infarction. Other vascular reconstructive procedures, including the use of autologous or synthetic bypass grafts and autotransplantation, produced cure of hypertension in 50% of children with improvement in a further 30%. The long-term outlook for children treated with surgical reconstructive procedures was excellent. One patient underwent surgery for avulsion of an arterial graft following a pubertal growth spurt. No other patient originally cured by surgery has required reoperation with no cases of restenosis at a mean follow-up of 11 years 3 months.

Adolescent↗

Etiology, prognosis, and outcome of post-operative acute renal failure.

A Multivariate analysis was done in all patients who developed post operative ARF, during the period 1990-1995 to determine the etiological spectrum and to identify various variables affecting the outcome. Of 140 patients (110 operated at SGPGI and 30 operated outside) 116 underwent elective surgery. The different types of surgery leading to ARF were urosurgery (3.5%), open heart surgery (32.9%), gastrosurgery (16.4%), pancreatic surgery (9.3%), obstetrical surgery (3.6%) and others (2.8%). The incidence of ARF in SGPGI patients was highest in pancreatic surgery group (8.2%) followed by open heart surgery (3%). The different etiological factors responsible for ARF were perioperative hypotension (67.1%), sepsis (63.6%) and exposure to nephrotoxic drugs (29.3%). Sixty-four patients (45.7%) required dialysis. The overall mortality was 45%. The mortality was highest in patients who underwent open heart surgery (89.1%) followed by pancreatic surgery (84.6%). The factors associated with high mortality, other than the type of surgery, were preoperative hypotension (p < 0.05), oliguria (p < 0.01), need for dialysis (p < 0.05) and multiorgan failure (p < 0.001). AM following emergency surgery had poor outcome, though not statistically significant. Perioperative sepsis (p < 0.05) and preoperative use of aminoglycoside (p < 0.05) were significantly higher in patients operated outside SGPGI. This was associated with higher incidence of ARF. Thus we conclude that presence of multiorgan failure, oligoanuria, preoperative hypotension and need far dialysis are poor prognostic markers in ARF following surgery.

Acute Kidney Injury↗

Acute renal failure associated with liver disease in India: etiology and outcome.

Acute renal failure (ARF) associated with liver disease is a commonly encountered clinical problem of varied etiology and high mortality. We have prospectively analyzed patients with liver disease and ARF to determine the etiology, clinical spectrum, prognosis and factors affecting the outcome. Other than hepatorenal syndrome patients, out of 221 cases, 66 developed ARF secondary to various liver disease like cirrhosis (n = 29, mortality 8, risk factors-older age p < 0.01, grade III/IV encephalopathy p < 0.05), fulminant hepatic failure (n = 25, mortality 15, risk factor-prolonged prothrombin time p < 0.01), and obstructive jaundice (n = 12, mortality 7, risk factor-sepsis p < 0.01). In these three groups the factors leading to ARF were volume depletion (24), gastrointestinal bleed (28), sepsis (34), drugs (27) [aminoglycosides (9) and NSAID (18)] along with hyperbilirubinemia. Various types of ARF with contemporaneous liver injury were malaria (n = 37, mortality 15, risk factors-higher bilirubin p < 0.001, higher creatinine p < 0.05, anuria p < 0.05 and dialysis dependency p < 0.05), sepsis (n = 36, mortality 22, risk factors-age p < 0.001, higher bilirubin p < 0.01, oliguria p < 0.05), hypovolemia with ischemic hepatic injury (n = 14, mortality 5, risk factors-higher creatinine p < 0.05 and SGPT p < 0.01), acute pancreatitis (n = 12, mortality 4, risk factors-higher bilirubin p < 0.001, higher SGPT p < 0.01, dialysis dependency p < 0.05), rifampicin toxicity (n = 10, no mortality), paroxysmal nocturnal hemoglobinuria (n = 3, no mortality), CuSO4 poisoning (n = 3 mortality 2), post abortal (n = 11, mortality 6, risk factors higher creatinine p < 0.05 and SGPT p < 0.01), ARF following delivery including HELLP syndrome (n = 12, mortality 4, risk factors-higher bilirubin p < 0.01 and SGPT p < 0.01), and of uncertain etiology (n= 14 mortality 4). 133 patients (60.2%), required hemodialysis hemodialfiltration or peritoneal dialysis. ARF associated with liver disease is having high mortality (42.5%). Avoidance of dehydration, hypotension, nephrotoxic drugs and sepsis, with promote dialytic support are necessary to reduce mortality and morbidity.

Acute Kidney Injury↗

Intravenous pulse cyclophosphamide--a new regime for steroid resistant focal segmental glomerulosclerosis.

OBJECTIVE: A prospective study was conducted to evaluate the role of intravenous pulse cyclophosphamide (IVCP) infusions in the management of children with steroid resistant (SR) idiopathic focal segmental glomerulosclerosis (FSGS). METHODS: The study group comprised of 20 consecutive children with idiopathic nephrotic syndrome secondary to FSGS who were SR. All of them were subjected to standard baseline investigations. They were started on monthly infusions of IVCP in a dose of 500-750 mg/m2. Adjunctive prednisolone was given in a dose of 60 mg/m2/day for 4 weeks followed by 40 mg/m2/alternate day for another 4 weeks and tapered off over next 4 weeks. RESULTS: The study group comprised of 15 boys and 5 girls with mean age of onset of disease of 5.5 +/- 3.5 years. Two of these children had chronic renal insufficiency prior to starting therapy. At the end of the study, after a mean duration of disease (since onset of NS) of 77 +/- 55 months, all 20 children had normal renal functions. After a mean follow up post IVCP therapy of 21.2 +/- 13.4 months, 13 of the 20 children (65%) had attained a complete remission. Of these, 10 children were infrequent relapsers, 2 frequent relapsers and 1 steroid dependent. The mean duration of remission following last dose of IVCP in these children was 12.5 +/- 11.9 months. Of the 7 children who continued to be proteinuric, 3 became edema free and have not required any albumin infusion or diuretics. One other died due to peritonitis 2 years after the last dose of IVCP. The mean total protein and serum albumin levels following the IVCP infusion were significantly higher than those prior to therapy (6.5+/-1.0 mg/dl Vs 5.0+/-0.8) (p=0.0004) and (3.5+/-0.7 g/dl Vs 2.3+/0.7) (p = 0.000007) respectively. The serum creatinine levels following IVCP therapy (0.8+/-0.2 mg/dl) were significantly lower than those prior to treatment (1.0+/-0.6 mg/dl) (p=0.02). The only side effects that were observed were transient nausea and vomiting during infusion (n=2) and alopecia (n=1). None of the children developed leukopenia or hemorrhagic cystitis. CONCLUSION: IVCP infusions appear to be safe, effective and economical therapeutic modality in steroid resistant children with idiopathic FSGS.

Analysis of Variance↗

Single-photon emission computed tomography (SPECT) in childhood epilepsy.

The success of epilepsy surgery is determined strongly by the precise location of the epileptogenic focus. The information from clinical and electrophysiological data needs to be strengthened by functional neuroimaging techniques. Single photon emission computed tomography (SPECT) available locally has proved useful as a localising investigation. It evaluates the regional cerebral blood flow and the comparison between ictal and interictal blood flow on SPECT has proved to be a sensitive nuclear marker for the site of seizure onset. Many studies justify the utility of SPECT in localising lesions to possess greater precision than interictal scalp EEG or anatomic neuroimaging. SPECT is of definitive value in temporal lobe epilepsy. Its role in extratemporal lobe epilepsy is less clearly defined. It is useful in various other generalized & partial seizure disorders including epileptic syndromes and helps in differentiating pseudoseizures from true seizures. The need for newer radiopharmaceutical agents with specific neurochemical properties and longer shelf life are under investigation. Subtraction ictal SPECT co-registered to MRI is a promising new modality.

Brain↗

Serum levels of lipoprotein (a) and other lipids in angiographically defined coronary artery disease patients and healthy blood bank donors.

Lipoprotein (a) (Lp(a)) and other lipid values have been correlated with angiographically defined [table: see text] coronary artery disease. To study this relationship in Indian patients, plasma levels of Lipoprotein (a) and other lipids were assessed in 74 patients undergoing Coronary arteriography and also in 53 age and sex matched healthy male blood bank donors who served as controls. Total cholesterol (mg/dl) (211 +/- 56 vs 186 +/- 43; p < 0.001), low density lipoprotein Cholesterol (mg/dl) (117 +/- 40 vs 88 +/- 29; p > 0.001) and low density lipoprotein/high density lipoprotein cholesterol ratio (2.6 +/- 0.8 vs 2.2 +/- 0.9; p < .001) were significantly higher in patients than controls. High density lipoprotein-cholesterol (mg/dl) (43.5 +/- 6 vs 42.1 +/- 7; p-ns) very low density lipoprotein-cholesterol (mg/dl) (49.7 +/- 17 vs 56.1 +/- 25; p-ns) and triglycerides (mg/dl) (155 +/- 101 vs 167 +/- 88; p-ns) were not statistically different in two groups. Lipoprotein (a) levels showed highly skewed distribution. Patients (n = 74) showed almost five fold higher lipoprotein (a) levels (mg/dl) as compared to controls (n = 53) [105 +/- 565 vs 23 +/- 76]. Patients with very high lipoprotein (a) levels [values of more than 40 mg/dl] (n = 18) had high density lipoprotein cholesterol and total cholesterol significantly lower than rest of the patient group. [high density lipoprotein cholesterol (mg/dl) 41.00 +/- 3.7 vs 44 +/- 6.4; p < 0.01 and total cholesterol (mg/dl) 192 +/- 34 vs 217 +/- 53; p < 0.05].

Adult↗

Interrelationship between angiographically defined coronary artery disease, plasma insulin levels and lipids in Indian patients.

We investigated the interrelationship between plasma insulin levels, various lipoproteins and coronary artery disease. No significant differences were observed on comparing patients with controls for plasma insulin, high density lipoprotein cholesterol, fasting blood sugar levels and triglyceride levels. However patients showed significantly higher levels of total cholesterol and low density lipoprotein cholesterol compared with controls. No significant differences were observed on comparing patients of multivessel disease with single vessel disease in serum insulin or various lipid subfractions. In addition, there was no correlation between serum insulin quartiles and various biochemical parameters. In conclusion, in this cross-sectional study plasma insulin levels failed to show any significant association with severity and extent of coronary artery disease. Further there was no correlation of various lipid parameters with insulin quartiles.

Adult↗

Structural and immunochemical characterization of a Neisseria gonorrhoeae epitope defined by a monoclonal antibody 2C7; the antibody recognizes a conserved epitope on specific lipo-oligosaccharides in spite of the presence of human carbohydrate epitopes.

Lipo-oligosaccharides (LOS) produced by Neisseria gonorrhoeae are important antigenic and immunogenic components of the outer membrane complex. Previously, we showed that murine monoclonal antibody (mAb) 2C7 did not cross-react with human glycosphingolipids but identified the LOS epitope that is widely expressed in vivo and in vitro (Gulati, S., McQuillen, D. P., Mandrell, R. E., Jani, D. B., and Rice, P. A. (1996) J. Infect. Dis. 174, 1223-1237). In the present study, we analyzed the structure of gonococcal strain WG LOS containing the 2C7 epitope and investigated the structural requirements for expression of the epitope. We determined that the WG LOS components are Hep[1]-elongated forms of 15253 LOS that have a lactose on both Hep[1] and Hep[2] (Yamasaki, R., Kerwood, D. E., Schneider, H., Quinn, K. P., Griffiss, J. M., and Mandrell, R. E. (1994) J. Biol. Chem. 269, 30345-30351). In addition, we found that expression of the 2C7 epitope within the LOS is blocked when the Hep[2]-lactose is elongated. Based on the structural data of these LOS and the results obtained from immunochemical analyses, we conclude the following: 1) mAb 2C7 requires both the 15253 OS minimum structure and the N-linked fatty acids in the lipoidal moiety for expression of the epitope; 2) mAb 2C7 binds to the LOS that elongates the lactose on Hep[1] of the 15253 OS, but not the one on Hep[2]; and 3) the 2C7 epitope is expressed on gonococcal LOS despite the presence of human carbohydrate epitopes such as a lactosamine or its N-acetylgalactosaminylated (globo) form. Our study shows that the conserved epitope defined by mAb 2C7 could potentially be used as a safe site for the development of a vaccine candidate.

Antibodies, Bacterial↗

Posttranscriptional regulation of mammalian methionine synthase by B12.

Methionine synthase is one of two key enzymes involved in the removal of the metabolite, homocysteine. Elevated homocysteine levels constitute a risk factor for cardiovascular diseases and for neural tube defects. In cell culture, the activity of methionine synthase is enhanced several-fold by supplementation with its cofactor, B12. The mechanism of this regulation is unknown, although it has been ascribed to a shift from apoenzyme to holoenzyme. Using sensitive assay techniques as well as a combination of Northern and Western analyses, we demonstrate that the effect of B12 on induction of methionine synthase activity is paralleled by an increase in the level of the enzyme. These studies exclude conversion of apoenzyme to holoenzyme as a basis for activation that had been described previously. Since the mRNA levels do not change during the same period that the methionine synthase levels increase, regulation of this protein by its cofactor must be exerted posttranscriptionally.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗

Etiology and outcome of chronic renal failure in Indian children.

A prospective analysis of all new pediatric cases of chronic renal failure (CRF) was performed at our hospital over a 1-year period. The diagnosis of CRF was based on serum creatinine >2 mg/dl with supportive clinical, laboratory, and radiological findings. There were a total of 48 patients with CRF with a median age of 13 years (range 10 days to 16 years). The causes of CRF included glomerulonephritis (37.5%), obstruction and interstitial (52%), hereditary (6.3%), and undetermined (4.2%). Patients were symptomatic for a mean of 33.2 months (range 10 days to 11 years) at presentation. Eight patients (16.7%) had acute reversible deterioration of renal function at presentation. This was due to accelerated hypertension in 2, infection in 3, volume depletion in 2, and nonsteroidal antiinflammatory drugs in 1 patient. At presentation, 22 (46%) children had mild to moderate renal failure and 26 (54%) had end-stage renal disease. Twenty-one children (43. 7%) had associated illness at presentation. Mean follow-up was 22.9 weeks (range 2-126 weeks). At the end of the study period, 10 (21%) patients were on conservative treatment, 7 (14.6%) on maintenance dialysis, 8 (16.7%) patients had functioning allografts, 4 (8.3%) patients had died, and 19 (39.6%) opted against further therapy. We conclude that CRF in Indian children carries a poor prognosis due to late referral and the limited availability and high cost of renal replacement therapy.

Adolescent↗

Changing trends of histopathology in childhood nephrotic syndrome.

This study was conducted to analyze the trend of histopathologic subtypes in idiopathic nephrotic syndrome (INS) in a homogenous racial group in India population. A prospective analysis of 400 consecutive children with INS was performed. Kidney biopsies were performed according to standard indications. Steroids were administered following the Arbeitsgeminschaft fur Padiatrische Nephrologie protocol. Cyclophosphamide was administered to children in the frequent-relapser, steroid-dependent, and steroid-nonresponder categories. Of the various histopathologic subtypes, focal segmental glomerulosclerosis (FSGS) was the most common (87 of 222 subtypes; 39.1%). Children who underwent biopsy between July 1992 and December 1996 (group B, n = 157) were compared with our initial published data of biopsies performed between January 1990 and June 1992 (group A, n = 65), with similar indications for biopsy in both groups. The incidence of FSGS was significantly greater in biopsies performed in the recent period (group B, 47% versus group A, 20%; P = 0.0002). The different clinical and biochemical parameters were also analyzed to differentiate FSGS from the other 2 subtypes. Hypertension (P = 0. 005), renal insufficiency at presentation (P = 0.001), and steroid resistance (P = 0.0006) were significantly greater in children with FSGS. On follow-up (mean, 5.4 years), children with FSGS were at a significantly greater risk for developing renal insufficiency (P = 0. 0001). We conclude there is a shift toward an increasing prevalence of FSGS over the years in the Indian population. This trend has immense therapeutic and prognostic significance.

Adolescent↗

Complement processing and immunoglobulin binding to Neisseria gonorrhoeae determined in vitro simulates in vivo effects.

Local inflammation elicited by Neisseria gonorrhoeae correlates closely with sensitivity to killing by normal human serum. Serum-sensitive (SS) isolates are rendered resistant in vitro by lipooligosaccharide sialylation. Differences in C3b processing on N. gonorrhoeae in vitro were found to match findings at the cervical level in vivo. Nonsialylated SS gonococci bound 5-fold more C3b than did stably serum-resistant (SR) gonococci; most was processed to iC3b, yet significant C3b persisted. Sialylated SS gonococci bound 4-fold less total C3 antigen than did SR gonococci, which was promptly converted to iC3b. C3b bound later on stably SR gonococci but again was processed swiftly to iC3b. In vivo, the iC3b/C3 ratio of SS isolates more closely resembled nonsialylated SS isolates in vitro, implying heterogeneous sialylation or desialylation in vivo. In vitro, total IgM bound was unchanged by sialylation of SS isolates, but total C4 bound decreased by 75%, suggesting that sialylation may indirectly regulate the classical complement pathway.

Animals↗

An essential saccharide binding domain for the mAb 2C7 established for Neisseria gonorrhoeae LOS by ES-MS and MSn.

A study of bacterial surface oligosaccharides were investigated among different strains of Neisseria gonorrhoeae to correlate structural features essential for binding to the MAb 2C7. This epitope is widely expressed and conserved in gonococcal isolates, characteristics essential to an effective candidate vaccine antigen. Sample lipooligosaccharides (LOS), was prepared by a modification of the hot phenol-water method from which de-O-acetylated LOS and oligosaccharide (OS) components were analyzed by ES-MS-CID-MS and ES-MSnin a triple quadrupole and an ion trap mass spectrometer, respectively. Previously documented natural heterogeneity was apparent from both LOS and OS preparations which was admixed with fragments induced by hydrazine and mild acid treatment. Natural heterogeneity was limited to phosphorylation and antenni extensions to the alpha-chain. Mild acid hydrolysis to release OS also hydrolyzed the beta(1-->6) glycosidic linkage of lipid A. OS structures were determined by collisional and resonance excitation combined with MS and multistep MSn which provided sequence information from both neutral loss, and nonreducing terminal fragments. A comparison of OS structures, with earlier knowledge of MAb binding, enzyme treatment, and partial acid hydrolysis indicates a generic overlapping domain for 2C7 binding. Reoccurring structural features include a Hepalpha(1-->3)Hepbeta(1-->5)KDO trisaccharide core branched on the nonreducing terminus (Hep-2) with an alpha(1-->2) linked GlcNAc (gamma-chain), and an alpha-linked lactose (beta-chain) residue. From the central heptose (Hep-1), a beta(1-->4) linked lactose (alpha-chain), moiety is required although extensions to this residue appear unnecessary.

Antibodies, Bacterial↗

Biotyping of Acinetobacter species isolated from clinical samples.

We used the biotyping scheme using carbohydrate substrate utilization test with 14 carbon sources to speciate Acinetobacter isolates from blood and cerebrospinal fluid cultures of patients admitted to the postoperative neurosurgery ICU during January to November 1996. Sixty one patients culture positive for Acinetobacter sp. from blood or cerebrospinal fluid were followed up prospectively. Among these patients, 40 patients had clinically diagnosed infections like bacteriemia or meningitis while in 21 patients the isolation was regarded as contaminants. A. baumanniii was the most common isolate associated with clinical infections while A. lwoffii was more likely to be an environmental contaminant.

Acinetobacter↗