Cytogenetic analysis in human breast tumors

Cytogenetic analysis using C-, G-, and Ag-nucleolus organizer region (NOR) staining techniques, performed on established cell lines as well as directly processed breast tumor effusions, revealed that: 1) chromosome No. 1 is involved in translocation; 2) based on 1q translocation chromosome, breast tumors could be classified into two groups; and 3) double minutes and homogeneously staining regions may be present in breast tumor cells in vivo as well as in vitro, and that homogeneously staining regions may exhibit some heterogeneity in staining.     

Combining aspirin with angiotensin converting enzyme inhibitors in heart failure: how safe is it?

The above discussion on the interaction of aspirin and ACE inhibitors seems to suggest that aspirin in high doses may have adverse interaction with ACE inhibitors in patients with heart failure but the data obtained is not sufficient or conclusive to recommended omission of aspirin in patients with heart failure. This raises a query in the mind of the physician whether to use a combination or not? The role of aspirin in the early period after myocardial infarction is well established so is the role of ACE inhibitors. Hence in patients with myocardial infarction and preserved left ventricular function it would not be wrong to administer combination of ACE inhibitors and aspirin. Albeit at a lower dose. In patients with large myocardial infarction or heart failure, warfarin may be an option but still needs to be documented in large trials. As suggested long term use of aspirin after infarction is still ambiguous and may be harmful in patients with heart failure with its anticedent side effects. But long term benefits of ACE inhibitors in heart failure are well documented. Hence if a choice has to be made whether to discontinue either of the two drugs it would be preferable to stop the aspirin. To answer the issue of use of aspirin in patients with heart failure it would be essential to conduct a double blind randomized trial comparing known anti-thrombotic treatment, aspirin and anti-coagulants on mortality in patients with heart failure, especially caused by coronary artery disease. Such a trial is underway at the present and till the results are available it should be left to clinical judgement of the physician whether to administer aspirin in patients with heart failure after weighing the benefits versus risk.     

Role of micro-nutrients and trace elements in carcinoma of larynx

Cancer of the larynx is fourteenth most common cancer in the world. Evidence from case-control studies conducted in developed as well as developing countries suggest that specific micro-nutrients and trace elements have been implicated to be significantly associated with laryngeal carcinoma. The association of these micro-nutrients and trace elements with laryngeal cancer has been discussed in this review article.     

Partial purification and characterization of B cell growth factor constitutively secreted by human T-cell hybridoma

Human T cell hybridomas were established by fusion of PHA-activated PBL with the 8-azaguanine resistant human T-leukemic cell line CEM-CM3. High levels of B cell growth factor (BCGF) activity were detected in the supernatants of hybridoma C8-2B2 and its subclones. Hybridoma C8-2B2, in addition to the Leu 3a, also expressed the OKT11 surface marker which was not detectable on the parent CEM-CM3 cells. BCGF from the culture supernatant was purified by combined use of salt fractionation and gel filtration to 36.6 fold with 23.9% recovery of activity. The BCGF produced by hybridoma C8-2B2 has a molecular weight range of 16,000–20,000 in two major electrophoretically different forms with pI values of 6.4 and 7.4.     

The restorative effect of naps on perceptual deterioration

Human performance on visual texture discrimination tasks improves slowly (over days) in the absence of additional training. This 'slow learning' requires nocturnal sleep after training and is limited to the region of visual space in which training occurred. Here, we tested human subjects four times in one day and found that with repeated, within-day testing, perceptual thresholds actually increased progressively across the four test sessions. This performance deterioration was prevented either by shifting the target stimuli to an untrained region of visual space or by having the subjects take a mid-day nap between the second and third sessions.     

Emblica officinalis Gaertn and serum cholesterol level in experimental rabbits.

Twelve albino rabbits of either sex weighing 1.0-1.25 kg were fed a standard laboratory diet of green grass and sattu (roasted Bengal gram). After a 2-week run-in period their serum cholesterol levels were estimated. All animals were now fed 0.5 g cholesterol and 1.0 g clarified butter daily and were not divided into 3 groups of 4 animals each. While all received the standard cholesterol-rich diet, Group A animals received no additional substances, animals in Group B were each fed 10 mg vitamin C daily, while those in Group C were each given 1.0 g fresh Amla (Emblica officinalis Gaertn). Mean serum cholesterol levels in all three groups rose to significantly higher levels by the end of the second week. There was a further rise by the end of the third and fourth weeks in Groups A and B. However, animals in Group C (i.e. those given Amla) showed significantly lower mean serum cholesterol levels at the end of the second week than their counterparts in Groups A and B. At the end of the third and fourth weeks the differences were even more pronounced.     

Interferon Production by Macrophages from Adult and Newborn Rabbits Bearing Fibroma Virus-Induced Tumors

Tumors were induced in adult and newborn rabbits by inoculation of fibroma virus. After 10 to 14 days, oil-induced peritoneal macrophages were harvested, purified, and tested in vitro for interferon synthesis after stimulation with specific and nonspecific viruses. Peritoneal macrophages from adult rabbits that had initiated tumor regression produced high levels of interferon (titers ranged from 160 to 640) after stimulation with fibroma virus, whereas macrophages from normal adult rabbits failed to produce significant levels of interferon under the same conditions (titers ranged from <10 to 10). Furthermore, fibroma-immune macrophages responded to vaccinia virus and Newcastle disease virus with higher levels of interferon than did normal macrophages. In contrast, macrophages from newborn tumor-bearing rabbits that showed no evidence of tumor regression failed to respond to fibroma virus stimulation with higher levels of interferon (titers ranged from <10 to 10). These macrophages did, however, yield significantly more interferon than newborn control macrophages when stimulated with a good interferon inducer, Newcastle disease virus (titers ranged from 10 to 80). These data suggest that interferon production may be an expression of macrophage activation to fibroma antigens and that macrophage activation is impaired in newborn rabbits with progressive growing tumors.     

Elevated telomere-telomere recombination in WRN-deficient, telomere dysfunctional cells promotes escape from senescence and engagement of the ALT pathway

Werner Syndrome (WS) is characterized by premature aging, genomic instability, and cancer. The combined impact of WRN helicase deficiency and limiting telomere reserves is central to disease pathogenesis. Here, we report that cells doubly deficient for telomerase and WRN helicase show chromosomal aberrations and elevated recombination rates between telomeres of sister chromatids. Somatic reconstitution of WRN function, but not a WRN helicase-deficient mutant, abolished telomere sister chromatid exchange (T-SCE), indicating that WRN normally represses T-SCEs. Elevated T-SCE was associated with greater immortalization potential and resultant tumors maintained telomeres via the alternative lengthening of telomere (ALT) pathway. We propose that the increased incidence of chromosomal instability and cancer in WS relates in part to aberrant recombinations between sister chromatids at telomeres, which facilitates the activation of ALT and engenders cancer-relevant chromosomal aberrations and tumor formation.