High glucose microenvironment and human mesenchymal stem cell behavior

High glucose (HG) culture conditions in vitro and persistent exposure to hyperglycemia in diabetes patients are detrimental to stem cells, analogous to any other cell type in our body. It interferes with diverse signaling pathways, i.e. mammalian target of rapamycin (mTOR)-phosphoinositide 3-kinase (PI3K)-Akt signaling, to impact physiological cellular functions, leading to low cell survival and higher cell apoptosis rates. While elucidating the underlying mechanism responsible for the apoptosis of adipose tissue-derived mesenchymal stem cells (MSCs), a recent study has shown that HG culture conditions dysregulate mTOR-PI3K-Akt signaling in addition to mitochondrial malfunctioning due to defective mitochondrial membrane potential (MtMP) that lowers ATP production. This organelle-level dysfunction energy-starves the cells and increases oxidative stress and ultrastructural abnormalities. Disruption of the mitochondrial electron transport chain produces an altered mitochondrial NAD+/NADH redox state as evidenced by a low NAD+/NADH ratio that primarily contributes to the reduced cell survival in HG. Some previous studies have also reported altered mitochondrial membrane polarity (causing hyperpolarization) and reduced mitochondrial cell mass, leading to perturbed mitochondrial homeostasis. The hostile microenvironment created by HG exposure creates structural and functional changes in the mitochondria, altering their bioenergetics and reducing their capacity to produce ATP. These are significant data, as MSCs are extensively studied for tissue regeneration and restoring their normal functioning in cell-based therapy. Therefore, MSCs from hyperglycemic donors should be cautiously used in clinical settings for cell-based therapy due to concerns of their poor survival rates and increased rates of post engraftment proliferation. As hyperglycemia alters the bioenergetics of donor MSCs, rectifying the loss of MtMP may be an excellent target for future research to restore the normal functioning of MSCs in hyperglycemic patients.

Transient small bowel intussusceptions: ultrasound findings and clinical significance

PURPOSE

To study the ultrasound (US) findings and clinical significance of transient small bowel intussusceptions (TSBI) in adults and children.

METHODS

Clinical records and US findings of 108 consecutive patients of intestinal intussusception diagnosed on US between August 1995 and August 2004 were reviewed. In all cases, the length, diameter, wall thickness and color Doppler study of the bowel segment involved in intussusception were evaluated. Subsequent follow-up scans were performed at 30 min, 3 days and 2 weeks. Patients were clinically followed up for 6 months.

RESULTS

Forty-one patients were diagnosed as TSBI. Thirty-six intussusceptions were incidentally detected during US performed for some unrelated disease or vague abdominal symptom. Five patients presented with signs of obstruction at the time of the initial US diagnosis; however, the intussusceptions resolved without any treatment and were not detected on follow-up scans. Sixty-seven symptomatic patients required surgical intervention.

CONCLUSION

Incidentally detected, small bowel intussusceptions without an identifiable pathological lead point, with a normal wall thickness, a length of less than 3.5 cm, normal nondilated proximal bowel and normal vascularity on color Doppler reduce spontaneously and are of no clinical significance.

Ultrasound in the diagnosis of typhoid fever

OBJECTIVES

To establish the efficacy of ultrasound (US) of the abdomen as a diagnostic test in Typhoid. To determine the ultrasound diagnostic criteria in cases of Typhoid.

METHODS

The Widal test is the most commonly used method of detecting Typhoid fever, but does not provide results until a week after onset of fever due to the need for enough antibodies to develop to render a positive result. Abdominal Ultrasound was performed within three days of the onset of fever in 80 cases suspected to be having Typhoid fever. Subsequent follow-up scans were performed at five days, ten days and fifteen days. Subsequently, all 80 cases were found to be Widal positive and Salmonella culture was positive in 32 cases. We present our findings in 26 patients in the age group between 4 to 20 years in whom both Widal test and Salmonella culture was subsequently positive.

RESULTS

The US findings were as follows: splenomegaly (n-26, 100%); Bowel wall thickening (n-22, 85%); mesenteric lymphadenopathy(n-20,77%); hepatomegaly with normal parenchymal echotexture (n-8, 31%); thickened gall bladder (n-16, 62%); biliary sludge (n-6, 23%); positive US Murphy's sign (n-7, 27%); pericholecystic edema with increased vascularity (n-6, 23%); mucosal ulceration in the wall of the gall bladder (n-1, 3.8%).

CONCLUSION

In endemic areas like India, ultrasound findings of hepatomegaly, splenomegaly, ileal and cecal thickening, mesenteric lymphadenopathy and thick-walled gallbladder are diagnostic features of typhoid. Ultrasound can be a non-invasive, economical and a reasonably sensitive tool for diagnosing typhoid when serology is equivocal and cultures are negative.

Multilayer-enzyme linked immunosorbent assay (ML-ELISA) for detection of Entamoeba histolytica trophozoite coproantigen

Multilayer ELISA (ML-ELISA) method for Entamoeba histolytica trophozoite coproantigen was developed for diagnosis of amoebiasis and its usefulness vis-a-vis microscopic examination analysed for paired specimens from 87 patients from Lucknow and Hyderabad, India. All the stool specimens positive for trophozoites were also found to be positive in ML-ELISA. Out of a total 32 samples positive for cysts in microscopy 21 (65.62%) gave positive reactions for coproantigen. Results on 26 samples drawn from otherwise healthy subjects with negative microscopical picture, 4 were positive for coproantigen. The results of the present study indicate that ML-ELISA test is suitable for early diagnosis of acute amoebic patients for timely treatment.