Low matrix metalloproteinase levels precede vascular lesion formation in the JCR:LA-cp rat

Molecular and Cellular Biochemistry - Clinically significant occlusive vascular lesions contain more extracellular matrix (ECM) proteins and lipid deposition than healthy vascular tissue. The...     

Two simple and rapid methods for the detection of polymer-degrading enzymes on high-resolution, alkaline, cold, in situ-native (HiRACIN)-PAGE and high-resolution, in situ-inhibited native (HiRISIN)-PAGE

Two sensitive, high-resolution and exceedingly versatile methods for the detection of isoenzymes of polymer-degrading enzymes on high-resolution, alkaline, cold, in situ-native (HiRACIN)-PAGE and high-resolution in situ-inhibited, native (HiRISIN)-PAGE are described. Extracellular crude extracts containing xylanases and carboxymethylcellulases from Scopulariopsis sp. and glucoamylases from Aspergillus niger were subjected to non-denaturing PAGE containing substrates in the resolving gel. In case of HiRACIN-PAGE, the enzymes were prevented from degrading their respective substrates during run by carrying out electrophoresis at 4°C and the pH of running and resolving gel buffer systems were increased from 8.5 to 10.6. In case of HiRISIN-PAGE, adding competitive inhibitor of the enzyme, cellobiose, in the resolving gel prevents the degradation of polymer during the run. These techniques were successfully applied, for the first time, to visualize four, three and four sharp and distinct bands of xylanases, glucoamylases and CMCases, respectively.     

Prevalence of exposure of heavy metals and their impact on health consequences

Even in the current era of growing technology, the concentration of heavy metals present in drinking water is still not within the recommended limits as set by the regulatory authorities in different countries of the world. Drinking water contaminated with heavy metals namely; arsenic, cadmium, nickel, mercury, chromium, zinc, and lead is becoming a major health concern for public and health care professionals. Occupational exposure to heavy metals is known to occur by the utilization of these metals in various industrial processes and/or contents including color pigments and alloys. However, the predominant source resulting in measurable human exposure to heavy metals is the consumption of contaminated drinking water and the resulting health issues may include cardiovascular disorders, neuronal damage, renal injuries, and risk of cancer and diabetes. The general mechanism involved in heavy metal‐induced toxicity is recognized to be the production of reactive oxygen species resulting oxidative damage and health related adverse effects. Thus utilization of heavy metal‐contaminated water is resulting in high morbidity and mortality rates all over the world. Thereby, feeling the need to raise the concerns about contribution of different heavy metals in various health related issues, this article has discussed the global contamination of drinking water with heavy metals to assess the health hazards associated with consumption of heavy metal‐contaminated water. A relationship between exposure limits and ultimate responses produced as well as the major organs affected have been reviewed. Acute and chronic poisoning symptoms and mechanisms responsible for such toxicities have also been discussed.     

The involvement of cytochromeP-450 monooxygenase system in aflatoxin biosynthesis byAspergillus flavus

Summary Phenobarbital stimulated aflatoxin biosynthesis byAspergillus flavus and this was paralleled by an increase in microsomal NADPH-cytochromeP-450 reductase and cytochromeP-450 activities. Aflatoxin biosynthesis was inhibited by SKF 525-A, metyrapone and cyanide, inhibitors of the cytochromeP-450 monooxygenase system, further suggesting that aflatoxin biosynthesis byA. flavus could be mediated by a cytochromeP-450 monooxygenase enzyme system.     

Interocular Retinal Nerve Fiber Layer Thickness Difference in Normal Adults

PurposeTo determine the interocular retinal nerve fiber layer (RNFL) thickness difference of normal subjects.MethodsBoth eyes of 230 normal adults received peripapillary RNFL thickness measurements using OCT. The effect of ocular cyclotorsion on the RNFL thickness profile was mathematically corrected. The fractional and absolute interocular RNFL thickness differences at 256 points of peripapillary area were calculated. We divided the subjects into 3 groups according to the locations of superior and inferior peak thickness, respectively, and compared the interocular RNFL thickness differences between the subgroups.ResultsThe fractional interocular RNFL thickness difference exhibited smaller regional variations than the absolute interocular difference. The means of fractional interocular differences were 0.100 ± 0.077 in the temporal half area and 0.146 ± 0.105 in the nasal half area, and the tolerance limits for the 95th and 99th distributions were about 0.246 and 0.344 in the temporal half area and 0.293 and 0.408 in the nasal half area, respectively. The fractional interocular differences of subgroups classified by the locations of superior and inferior peak RNFL thickness showed difference at smaller areas than the absolute interocular differences (19 and 8 points versus 49 and 23 points, respectively).ConclusionGlaucoma can be strongly suspected, if interocular fractional RNFL thickness difference is over 25% at 5 consecutive points or over 35% at 3 consecutive points in the temporal half area. The fractional interocular comparison is a better diagnostic approach because the fractional interocular RNFL thickness difference is less influenced by the locations of peak RNFL thickness.     

Ehd4 is required to attain normal prepubertal testis size but dispensable for fertility in male mice

The four highly homologous members of the C‐terminal EH domain‐containing (EHD) protein family (EHD1‐4) regulate endocytic recycling. To delineate the role of EHD4 in normal physiology and development, mice with a conditional knockout of the Ehd4 gene were generated. PCR of genomic DNA and Western blotting of organ lysates from Ehd4^−/− mice confirmed EHD4 deletion. Ehd4^−/− mice were viable and born at expected Mendelian ratios; however, males showed a 50% reduction in testis weight, obvious from postnatal day 31. An early (Day 10) increase in germ cell proliferation and apoptosis and a later increase in apoptosis (Day 31) were seen in the Ehd4^−/− testis. Other defects included a progressive reduction in seminiferous tubule diameter, dysregulation of seminiferous epithelium, and head abnormalities in elongated spermatids. As a consequence, lower sperm counts and reduced fertility were observed in Ehd4^−/− males. Interestingly, EHD protein expression was seen to be temporally regulated in the testis and EHD4 levels peaked between days 10 and 15. In the adult testis, EHD4 was highly expressed in primary spermatocytes and EHD4 deletion altered the levels of other EHD proteins in an age‐dependent manner. We conclude that high levels of EHD1 in the adult Ehd4^−/− testis functionally compensate for lack of EHD4 and prevents the development of severe fertility defects. Our results suggest a role for EHD4 in the proper development of postmitotic and postmeiotic germ cells and implicate EHD protein‐mediated endocytic recycling as an important process in germ cell development and testis function. genesis 48:328–342, 2010. © 2010 Wiley‐Liss, Inc.