Mechanism of ovalbumin proteolysis

Papain, thermitase and pepsin at pH 4.0 hydrolyze ovalbumin to low molecular weight peptides. Simultaneously a stepwise formation of several short fragments resulting in the appearance of a group of high molecular weight fragments and a subsequent splitting of the latter into two fragments of intermediate molecular mass takes place. The fragments are retained in the molecule by noncovalent bonds. The fragments formed under the action of different enzymes are similar in size, which is suggestive of splitting in the same narrow segments of the ovalbumin polypeptide chain. The results obtained indicate that during proteolysis of the native ovalbumin two extreme types of the proteolysis--the one-by-one and zipper types--occur in parallel, while the course of the latter is largely determined by the ovalbumin structure.     

Ketorolac tromethamine in the maintenance of intraoperative mydriasis

BACKGROUND AND OBJECTIVE: Mydriatics and antiprostaglandins are routinely applied preoperatively to facilitate the aspiration of cortical material during extracapsular cataract surgery and to prevent intraoperative miosis. Unfortunately, the ideal antiprostaglandin has yet to be introduced. This study represents the first prospective, case-controlled, randomized, masked, clinical trial comparing the efficacy of oral ketorolac tromethamine (KT) with the efficacy of topical flurbiprofen sodium (FS) and a placebo (normal saline) in maintaining intraoperative mydriasis without adrenaline in the irrigation solution. PATIENTS AND METHODS: Sixty-three patients, undergoing extracapsular cataract extraction with posterior chamber intraocular lens implantation, were randomly divided into three equal groups. Group 1 received 20 mg of oral KT 2 hours prior to surgery, group 2 received 0.03% FS topical solution at the recommended dosage, and group 3 received topical normal saline in a regimen identical to that of group 2. Identical mydriatics were used in both groups. The patients' pupils were measured at five stages of surgery. RESULTS: The mean pupillary diameters at each surgical stage were greater in group 1 than in group 2; however, the difference was not statistically significant. The pupils in group 3 were significantly smaller than those of group 1 or group 2 (P < .05). No systemic toxicity to KT was observed. Moreover, the need for additional postoperative analgesics was significantly greater in groups 2 and 3. CONCLUSIONS: Oral KT is safe, convenient, and as effective as topical FS, and has the added advantage of reducing postoperative pain.     

Myocardial revascularisation in elderly patients with refractory or unstable angina and advanced coronary disease

BACKGROUND: Elderly patients with ischaemic heart disease are often treated more conservatively and for longer than younger patients, but this strategy may result in subsequent invasive intervention of more advanced and higher risk coronary disease. METHODS: We performed a retrospective analysis of 109 patients aged > or = 70 years (mean age 74 years, 66% men), who presented with angina refractory to maximal medical treatment or unstable angina over a 2-year period (1988-1990), to compare the relative risks and benefits of myocardial revascularisation [coronary artery bypass grafting (CABG) and percutaneous transluminal coronary angioplasty (PTCA)] in this higher-risk age group. RESULTS: Sixty patients underwent CABG and 49 patients PTCA. There were eight periprocedural deaths in total (six in the CABG group, and two in the PTCA group, P = 0.29). Six patients in the CABG group suffered a cerebrovascular accident (two fatal). Acute Q-wave myocardial infarction occurred in one patient in the CABG group and in two patients in the PTCA group. The length of hospital stay was longer for the CABG group (CABG group 11.4 +/- 5.4 days, range 7-30 days, PTCA group 7.4 +/- 7.6 days, range 1-39 days, P = 0.01). Outcome was assessed using the major cardiac event rate (MACE; i.e. the rate of death, myocardial infarction, repeat CABG or PTCA). The cumulative event-free survival in the CABG group in 1, 2 and 3 years was 87, 85 and 85%, respectively. In contrast, in the PTCA group it was 55, 48 and 48% (P = 0.0001). Age, sex, number of diseased vessels, degree of revascularisation and left ventricular function were not predictive of the recurrence of angina in both groups. Actuarial survival (total mortality, including perioperative mortality) was lower at 1 year in the CABG group due to the higher perioperative mortality, but similar in both groups after the second year (P = 0.62). CONCLUSIONS: Elderly patients with refractory or unstable angina who are revascularised surgically have a better long-term outcome (less frequent event rate of the composite end-point--myocardial infarction, revascularisation procedures and death) compared with those who are revascularised with PTCA. This benefit is been realised after the second year. Total mortality is similar in both groups after the second year. Therefore elderly patients who are fit for surgery should not be denied the benefits of CABG. PTCA may be regarded as a complementary and satisfactory treatment, especially for those whose life expectancy is limited to less than 2 years. The use of stents may improve outcome in the PTCA group and this needs to be evaluated.     

Central nervous system cryptococcosis: parenchymal calcification and large gelatinous pseudocysts

In an 11-year-old immunocompetent girl with protracted cryptococcal infection of the central nervous system, CT showed multiple areas of parenchymal calcification. MR imaging showed large gelatinous pseudocysts around the brain stem. These imaging features and the child's age are unusual for intracranial cryptococcosis.     

Ceftriaxone in treatment of streptococcal endocarditis

The authors studied efficacy and safety of ceftriaxone given intravenously for 3-4 weeks in a dose 2-4 g/day to patients with streptococcal endocarditis (SE). Of them, 8, 8 and 1 patients were infected with Streptococcus viridans, Streptococcus pyogenes, Pneumococcus, respectively. Hospital trial and follow-up lasted up to 2 years. Cure without surgical correction occurred in 7 patients, valvular replacement was needed in 4 patients, 1 patient died, 4 patients developed recurrences 3 and more months after therapy with ceftriaxone. The drug was safe and well tolerated. 33% of the patients were discharged from hospital with obvious improvement after 2-3 week treatment to continue it outpatiently for 1-2 weeks.     

Comparison of glycoprotein components, tryptophan, lipid peroxidation and antioxidants in borderline and severe hypertension and myocardial infarction

Between 1957 and 1993, the Siberian Chemical Complex (Tomsk-7) located in the Tomsk region (Russia) regularly discharged radioactive liquid wastes into the Tom River which resulted in an extensive contamination of large territories with long lived radionuclides such as cesium-137 and strontium-90. In the summers of 1996 and 1997, Research Team of Siberian Medical University conducted biodosimetry and cytogenetic monitoring of pikes (Esox lucius) caught in the Tom River at various distances downstream from the Siberian Chemical Complex (SCC) using the micronucleus test and the gamma spectroscopy. Our findings demonstrated that the difference in frequency of micronucleated erythrocytes between the radiation-exposed fish caught downstream from the SCC and the controls was statistically significant (P < 0.01). Moreover, we found a good correlation between radiocesium concentration and micronucleated erythrocyte frequency in pikes. It was found that both the micronucleated erythrocyte frequency in pike blood and the level of the pike radiocesium concentration depended on the age of pikes. The micronucleated erythrocyte frequency gradually increased from the 1-year-old pikes to the over 20-year-old pikes. On the other hand, the average level of radiocesium concentration gradually increased from the 1-year-old pikes only up to the 10-year-old pikes. There is no correlation between radiocesium concentration and micronucleated erythrocyte frequency in the over 10-year-old pikes.     

Permeability of blood-eye barrier in patients with primary glaucoma combined with lens opacity

The paper focuses on the history and sources of origin of sanology as science, with its brief characterization being given, relating to such items as definition, object and subject of investigation, methodological approaches and tasks, with special emphasis being placed on the significance of sanology in the elaboration of general theory of medicine.     

Altered functional responsiveness of thymocyte subsets from CD3delta-deficient mice to TCR-CD3 engagement

CD3delta-deficient (delta degrees) mice are defective in alphabeta T cell development. Here we explore the capacity of TCR-CD3 signaling complexes expressed on delta degrees thymocytes to mediate the following functional outcomes in response to antibody cross-linking: (i) the transition from the CD4-CD8- to CD4+CD8+ stage, (ii) the transition from the CD4+CD8+ to CD4+CD8- or CD4-CD8+ stages and (iii) the induction of apoptosis. We provide evidence that CD3deltaepsilon complexes are dispensable for mediating the anti-CD3-mediated CD4-CD8- to CD4+CD8+ transition. On the other hand, CD3delta is critical at the CD4+CD8+ stage. We demonstrate that CD4+CD8+ thymocytes from delta degrees mice, unlike delta degrees CD4-CD8- thymocytes and wild-type CD4+CD8+ thymocytes, require prolonged or consecutive stimuli to elicit functional responses. Depending on the nature of the secondary stimulus, delta degrees thymocytes can be induced to undergo apoptosis or preferential maturation to the CD4-CD8+ stage. Taken together these results indicate that the signaling capacity of the TCR-CD3 complex is noticeably altered in the absence of CD3delta. The essential role of CD3delta at the CD4+CD8+ stage of development correlates with the onset of TCRalpha rearrangement, consistent with a critical structural and/or functional relationship between CD3delta and TCRalpha.