Low Molecular Weight Antioxidants (LMWA) and their Orchestration

Every day we hear more and more about free radicals and how they are linked with innumerable diseases and health conditions from ageing to muscular degeneration and even some forms of cancer. The problem is not in knowing that these microscopic enemies exist. We know that they do! The problem is how to fight them so that they are rendered harmless. Under normal metabolic conditions each cell of human body is exposed to about 1010 molecules of superoxide anions (primary free radical) each day. For a person weighing 150 pounds, this amounts to about 4 pounds of superoxide per year, a substantial amount! Once formed, superoxide can react through catalytic pathways in the cell to form many other reactive oxygen/nitrogen species (ROS/RNS). The antioxidant defense system in the human body is extensive and consists of multiple layers, which protect against different types of ROS/RNS. Many of the biological effects of antioxidants appear to be related to their ability not only to scavenge the deleterious free radicals but also to modulate cell signalling pathways.   Nepal Journal of Medical Sciences | Volume 02 | Number 02 | July-December 2013 | Page 171-180 DOI: http://dx.doi.org/10.3126/njms.v2i2.8971  

Novel mutations in typical and atypical genetic loci through exome sequencing in autosomal recessive cerebellar ataxia families

Nearly a thousand mutations mapping to 60 different loci have been identified in cerebellar ataxias. However, almost 50% of the cases remain genetically uncharacterized and there is a difference in prevalence as well as in the phenotypic spectrum of ataxia among various geographical regions. This poses a challenge for setting up a genetic panel for screening ataxia. In our ataxic cohort of 1014 families, 61% are genetically uncharacterized (UC). We investigated the potential of whole exome sequencing in conjunction with homozygosity mapping (HM) to delineate the genetic defects in three uncharacterized families with recessive inheritance each manifesting some unusual phenotype: (i) infantile onset ataxia with hearing loss (IOAH), (ii) Juvenile onset cerebellar ataxia with seizures (JCS) and (iii) Friedreich ataxia-like (FA-like). We identified a novel missense mutation in c10orf2 in the family with IOAH, compound heterozygous mutations in CLN6 in the family with JCS and a homozygous frame-shift mutation in SACS in the FA-like patient. Phenotypes observed in our families were concordant with reported phenotypes of known mutations in the same genes thus obviating the need for functional validation. Our study revealed novel variations in three genes, c10orf2, CLN6, and SACS, that have so far not been reported in India. This study also demonstrates the utility of whole exome screening in clinics for early diagnosis.

The spectrum of glomerular diseases in a single center: A clinicopathological correlation

We report the spectrum of biopsy-proven glomerular disease (GD) in a single center in Eastern India. Medical records of 666 patients with biopsy-proven GD over a period of 2 years from July 2010 to July 2012 were retrospectively analyzed. The clinical, laboratory, and histological data were recorded. All biopsy specimens were examined by the same pathologist with light and immunofluorescence microscopy. Electron microscopic analysis was performed only in selected cases. Histologic spectrum of various GDs was studied along with its correlation with the clinical and laboratory parameters. The clinical diagnosis was nephrotic syndrome (NS) in 410 (61.56%), rapidly progressive renal failure/glomerulonephritis in 130 (19.52%), subnephrotic proteinuria/asymtomatic urinary abnormalities in 52 (7.81%), acute kidney injury/acute nephritic syndrome in 40 (6.01%), and macroscopic hematuria in 4 (0.6%) patients. Male: Female ratio was 1.05; 27.92% (n = 186) were < 18 years, 68.47% (n = 456) were 18–59 years, and 3.6% (n = 24) were ≥ 60 years of age. The most common GD was minimal change disease (MCD) (20.12%, n = 134); others were focal segmental glomerulosclerosis (FSGS) (18.02%, n = 15.32%), lupus nephritis (LN) (15.32%, n = 102), membranous nephropathy (MN) (12.01%, n = 80), and IgA nephropathy (IgAN) (8.11%, n = 54). Primary GD was present in 79.13% (n = 527) and common histologies were MCD (25.42%), FSGS (22.58%), MN (14.42%), and IgAN (10.25%). Secondary GD was present in 20.87% (n = 139), with the most common being LN (73.38%, n = 102). Among the NS (n = 410), the most common GD was MCD (31.46%), followed by FSGS (25.6%), MN (15.58%), LN (7.8%), IgAN (6.09%), and membranoproliferative glomerulonephritis (4.88%). FSGS was the most common primary GD in adults, MCD in children, and MN in the elderly patients. The spectrum of GD varies according to the area of study and changes over time. A biopsy registry is needed for documenting this variation.

Cytomorphology of gastrointestinal stromal tumors and extra-gastrointestinal stromal tumors: A comprehensive morphologic study

BACKGROUND

The term gastrointestinal stromal tumors (GIST) is used to refer to those mesenchymal neoplasms of the gastrointestinal tract (GIT) which express CD117, a c-kit proto-oncogene protein.

AIMS

To study the cytological features of GIST and extra-gastrointestinal stromal tumors (EGIST), to correlate them with histology and to determine cytological indicators of malignancy.

MATERIALS AND METHODS

Cytological smears from patients diagnosed as GIST/EGIST on histology were retrieved. From Jan 2000 to July 2010, 26 GIST (13 primary, 12 metastatic, one recurrent) and seven EGIST (5 primary, one metastatic, one recurrent) cytologic samples from 27 patients were identified.

RESULTS

The patients included 20 males and 7 females with a mean age of 50.6 years. Tumor sites included stomach (5), duodenum (5), ileum (2), ileocecal (1), rectum (1), liver (9), retroperitoneum (5), mesentery (1), subcutaneous nodule (1), supra-penile lump (1), ascitic (1) and pleural fluids (1). The smears were cellular with cohesive to loosely cohesive thinly spread irregularly outlined cell clusters held together by thin calibre vessels. The tumor cells were mild to moderately pleomorphic, spindle to epithelioid with variable chromatin pattern and variable cytoplasm. Cellular dyscohesion, nuclear pleomorphism, intranuclear pseudoinclusions, prominent nucleoli, mitosis and necrosis were more prominent in malignant, metastatic and recurrent tumors.

CONCLUSIONS

GISTs show a wide spectrum of cytological features and the presence of mitosis, necrosis and nuclear pleomorphism can help in prediction of malignant behavior. Further, cytology is a very useful screening modality in patients of GIST and EGIST to detect early recurrence and metastasis at follow-up.

Clinical features, epidemiology, and short-term outcomes of proliferative lupus nephritis in Eastern India

Race and ethnicity are important predictors of prognosis in lupus nephritis. This study was conducted to determine the clinical features, epidemiological profile, and short-term outcomes in patients of lupus nephritis from a single center in Eastern India. A total of 86 patients of class III/IV lupus nephritis were studied. Seventy-eight of them received cyclophosphamide for induction and eight of them received mycophenolate. The patients were evaluated for response, estimated glomerular filtration rate (eGFR), and proteinuria at 6 months. About 44% patients had a partial or complete response at 6 months and 64% at 1 year. The factors correlating with response at 6 months were older age at diagnosis, hypertension, activity, and chronicity indices and duration of symptoms prior to therapy. Chronicity index and hypertension were the predictors of response by logistic regression at 6 months. Compared to the Caucasian and African American patients, patients with proliferative lupus in Eastern India presented with a lower eGFR, lower proteinuria, and higher chronicity scores. Older age at diagnosis, hypertension, activity, chronicity indices, and duration of symptoms correlated with response. Short-term outcomes were similar to those described in Caucasian patients.

Imaging characteristics of cavernous sinus cavernous hemangiomas

Cavernous hemangiomas occur rarely in the cavernous sinus and are difficult to diagnose preoperatively. The imaging of these lesions resembles other benign paracavernous lesions such as schwannomas and meningiomas. Profuse intraoperative bleeding may be encountered during surgical resection of these lesions. A preoperative diagnosis is therefore important to alert the surgeon. We report on the imaging characteristics of two different histopathological types of cavernous sinus cavernous hemangiomas and the use of contrast-enhanced MRI, diffusion-weighted MRI and magnetic resonance spectroscopy in the differential diagnosis of these lesions.

Antioxidant vitamins and chemoprevention

Free radicals play an important role in human carcinogenesis and the mechanism of their counteraction by antioxidant vitamins has been reviewed. It seems more likely that these vitamins work in concert rather than acting singly. Currently available data are compatible with the notion that these vitamins act as chemopreventives against some important cancers, e.g. carotenoids for lung cancer, ascorbic acid for salivary gland cancer, tocopherols for head and neck cancers etc. Thus, a greater consumption of fruits and vegetables should be encouraged as they are the natural sources of these chemopreventive, antioxidants along with other protective factors packaged by nature. However, much work still remains to be done to establish the role of antioxidant vitamins in carcinogenesis.

Hyperhomocysteinemia and cardiovascular disease: The nutritional perspectives

Several members of the vitamin B-complex family are known to participate in the normal metabolism of homocysteine (Hcy). Leaving aside the genetic determinants of hyperhomocysteinemia (HHC), the deficiencies of these vitamins can also result in HHC. The situation of sustained and long standing HHC is likely to be prevalent in population groups with low/average socio-economic status, geriatric population and alcohol abusers. If not corrected by supplementation, these population groups certainly are more vulnerable to develop atherosclerosis (AS) and subsequently, cardiovascular disease (CVD). Hyperhomocysteinemia per se and/or HHC-induced oxidative stress result(s) in chronic chemical endothelial injury/dysfunction, smooth muscle proliferation, prothrombotic state and oxidation of low density lipoproteins (LDL) leading to diverse cardiovascular complications. In the first decade of the new millennium, major research efforts would be directed towards understanding the basic mechanism of HHC-induced oxidative stress and the pathophysiology of HHC-induced CVD, culminating in the evolution of hitherto unknown therapeutic strategies such as nutriceuticals and oxidant-antidotes.

Modification of the Resch procedure

Controversy surrounds the management of displaced three- and four-part fractures of the proximal humerus. The percutaneous Resch technique of stabilisation involves minimal soft-tissue dissection and a reduced risk of stiffness and avascular necrosis. However, it requires a second operation to remove Kirschner wires and the humeral block. We describe a modification of this technique that dispenses with the need for this second operation and relies on a sequential pattern of screw placement. We report the outcome of 32 three- or four-part fractures of the proximal humerus treated in this way at a mean follow-up of 3.8 years (2 to 8)). There were 14 men and 18 women with a mean age of 56 years (28 to 83). At final follow-up the mean Oxford shoulder scores were 38 (31 to 44) and 39 (31 to 42), and the mean Constant scores were 79 (65 to 92) and 72 (70 to 80) for three- and four-part fractures, respectively. We further analysed the results in patients aged < 60 years with high-energy fractures and those aged ≥ 60 years with osteoporotic fractures. There were no cases of nonunion or avascular necrosis.

The results were good and comparable to those previously reported for the Resch technique and other means of fixation for proximal humeral fractures. We would recommend this modification of the technique for the treatment of displaced three-part and four-part fractures in patients both younger and older than 60 years of age.