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Biomedical subjects

J Sula

Publications and source records attributed to J Sula.

At least 19 recordsLinked to original sources
PubMed2004

Adjustments of the enzymatic complement for polyol biosynthesis and accumulation in diapausing cold-acclimated adults of Pyrrhocoris apterus.

The capacity to accumulate winter polyols (mainly ribitol and sorbitol) during cold-acclimation in Pyrrhocoris apterus is restricted only to the adults that have previously entered diapause. The enzymatic complement involved in polyol biosynthesis was found to differ in a complex manner between diapause and non-diapause adults. Nearly 100% of glycogen phosphorylase (GPase) was present in its active form in non-diapause adults irrespective of their acclimation status. In contrast, less than 40% of GPase was present in its active form in diapause adults prior to cold-acclimation and the inactive form was rapidly activated upon transition from 5 to 0 degrees C, concomitantly with the start of rapid polyol accumulation. The flow of carbon released by activation of glycogen degradation might be routed to the pentose cycle because the activity of glucose-6-P dehydrogenase (G(6)P-DH) was significantly higher and it increased with cold-acclimation in diapause adults while it was relatively low and it decreased with cold-acclimation in non-diapause adults. Reducing equivalents in the form of NADPH, which were generated in the pentose cycle, might require re-oxidation. Such re-oxidation might be achieved during reduction of sugars to polyols. The activity of NADP(H)-dependent aldose reductase (AR) was about 20-fold higher in diapause than in non-diapause adults. Similarly, the activity of NAD(H)-dependent polyol dehydrogenase (PDH) was higher in diapause adults. In addition, we found a very high activity of an unusual enzyme, NADP(H)-dependent ketose reductase (KR), exclusively in diapause adults. KR might be involved in reduction of fructose to sorbitol. Although its affinity for fructose as a substrate was low (K(M)=0.64M), its activity was about 10-fold higher than that of PDH with fructose. Moreover, the activity of KR significantly increased with cold-acclimation while that of PDH remained unchanged. Different electrophoretic mobilities in PAGE gel suggested that KR and PDH are two different enzymes with specific requirement for NADP(H) or NAD(H), respectively, as co-factors.

Acclimatization↗
PubMed1998

Physiology of drought tolerance and cold hardiness of the Mediterranean tiger moth Cymbalophora pudica during summer diapause.

Prepupae of the arctiid moth Cymbalophora pudica spend spring and summer months in a summer diapause (aestivation), the duration of which is photoperiodically controlled. Cold hardiness, drought tolerance and some physiological and biochemical parameters were measured in aestivating prepupae. Large amounts of metabolic reserves, in the form of lipids and glycogen, accumulated prior to aestivation. Glycogen served as the main metabolic fuel for aestivating prepupae. Metabolic rate decreased rapidly after the onset of the inactive prepupal stage and remained low (5-15% of the level in active larva) during aestivation. A spontaneous increase of the respiration rate occurred before pupation. Neither low mol. wt sugars or alcohols (polyols) accumulated nor the haemolymph osmotic pressure changed during aestivation. Drought tolerance of aestivating prepupae was high (no decrease in survival after exposure to r.h.<10% at a temperature of 23 degrees C for a substantial part of diapause) owing to their extensive capacity to stabilize the relative body water content irrespective of the r.h. of surrounding air. Cold hardiness was low (>90% decrease in survival after exposure to -7 degrees C for 24h). Cold and drought acclimations did not lead to significant changes in the measured physiological and biochemical parameters but cold (not drought) acclimation caused a significant increase in cold hardiness. Neither drought tolerance nor the increase in cold hardiness after cold acclimation appear to be related to presence/accumulation of polyols in aestivating C. pudica prepupae.

Journal Article↗
PubMed1998

Wing morph-related physiological differences in adults of temperate population of Pyrrhocoris apterus (L.) (Heteroptera: Pyrrhocoridae).

The reproductive and diapausing adult females of brachypterous morph and macropterous females with reproductive arrest of non-diapause type, originating from the laboratory cultures of Pyrrhocoris apterus, were studied for their feeding and drinking behaviour, digestive enzyme activities, and carbohydrate and lipid contents. The highest feeding and drinking activities were observed in reproductive brachypters, the lowest in macropters. Macropters also differed from brachypters by lower activities of gut lipase, peptidase and protease, lower concentration of haemolymph sugars, and lower weight of fat body, which probably reflects their low feeding activity. The total content of fat body lipids was also lower in macropters (0.6 mg) than in reproductive and diapausing brachypters (4.6 and 7.5 mg, respectively) on day 14. A very high amount of glycogen was found in the fat body of diapausing brachypters, 363 micrograms on day 14, as opposed to 15 and 80 micrograms in macropterous and reproductive brachypterous females, respectively. The obtained data indicate that the most important difference between macropterous and brachypterous females with different types of reproductive arrest consists of an enhanced mobilization of lipids for dispersal in macropters and accumulation of energetic reserves for hibernation in brachypters.

Amylases↗
PubMed1981

The influence of flight on the phospholipid metabolism in insect flight muscle.

Males of the American cockroach, Periplaneta americana, received an injection of 32P-orthophosphates and the specific activity of phosphatidylcholine (PC), phosphatidylethanolamine (PE) and phosphatidylinositol (PI) was determined after 120 min of in vivo incorporation. If the insects were forced to fly for 10 min immediately before the end of the experiment, the specific activity (S.A.) of PC and PE was lowered by 34.3 and 31.0%, respectively, that of PI by 17.5%. If the animals were allowed to rest for 10 min after cessation of flight, the S.A. of PC and PE did not differ significantly from the controls, whereas that of PI rose by 91.0% above the control value. These effects cannot be due to changes in precursor labelling (glycerophosphate and phosphoarginine were measured) and reflect changes in the rate of phospholipid biosynthesis. The possibility is discussed that mechanisms regulating the rate of phospholipid biosynthesis are involved.

Animals↗
PubMed1980

Pharmacy unit devises quality assurance plan.

As the basis for a total quality assurance program, a hospital's pharmacy department developed minimum standards of practice and a compliance audit procedure.

Hospital Bed Capacity, 500 and over↗
PubMed1979

Experimental data concerning the question of the synergic action of the influenza virus and of some chemical carcinogens in the pathogenesis of lung cancer.

The importance of new discoveries in the field of molecular biology concerning the interaction of oncogenic material in cell leading to a synthesis of knowledge in the field of viral and physico-chemical blastomogenesis is underlined. A concise reference to earlier studies and to the present state of knowledge is presented, with a subsequent review of the results of experimental studies dealing with the problem of the synergic action of influenza viruses (type A2, A/PRS, B, Sendai) and of chemical carcinogens (urethane, cancerogenic hydrocarbons, diethylnitrosamines, cigarette smoke) in the pathogenesis of lung cancer. Both the suggested and already demonstrated mechanisms of the joint action of viruses and chemical carcinogens, illustrating the interrelations between the two factors in the process of malignant transformation, are discussed.

Animals↗
PubMed1978

Gentamicin-cephalothin drug reaction.

A case report describing the occurrence of nephrotoxicity in a 26-year-old black male with sickle cell anemia after concurrent i.v. administration of gentamicin sulfate and cephalothin sodium is presented. Cephalothin 1 g.i.v. every six hours was given for three days for a Klebsiella infection demonstrated by urine and blood culture to be cephalosporin sensitive. Cephalothin was then discontinued and gentamicin, after an i.v. loading dose of 2.6 mg/kg, was given for 14 days in a dosage of 1.3 mg/kg every eight hours. After cultures of pus aspirated from the right thigh demonstrated Klebsiella, 2 g of cephalothin was administered i.v. every six hours and gentamicin sulfate was discontinued. Gentamicin therapy was reinstituted two days later, at a dosage of 5 mg/kg/day. The gentamicin-cephalothin therapy was continued for nine days. The gentamicin dosage interval was increased from every eight to every 16 hours when serum creatinine and gentamicin levels became elevated. Gentamicin was discontinued entirely two days later because serum gentamicin levels were not decreasing. Previous case reports and studies of nephrotoxicity associated with concurrent gentamicin-cephalothin therapy are reviewed. Pharmacists should be alert to the possible increased incidence of nephrotoxicity occurring with concurrent genticin-cephalothin therapy.

Adult↗