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Biomedical subjects

N Jan

Publications and source records attributed to N Jan.

At least 19 recordsLinked to original sources

Influence of insulin treatment and feed restriction on follicular development in cyclic gilts.

Crossbred gilts were used to investigate whether exogenous insulin can restore normal follicular growth in feed-restricted gilts. After an 18-day altrenogest treatment, the first day of oestrous behaviour was designed as day 0. From day 0 to 13, all gilts received the same amount of feed, calculated to meet 200% of the energy requirements for maintenance. On day 14, luteolysis was induced by injection of an analogue of prostaglandin F2alpha. All gilts were slaughtered on day 19 and their ovaries removed. In Experiment 1, gilts received a high (240% of maintenance) or low (80%) level of feeding (n=10/group) from day 14 to 18. The number of large follicles (> or = 5 mm) on day 19 was reduced in feed-restricted gilts (16.9 versus 20.6, P<0.05). The same protocol of feed restriction was used in Experiment 2 (240% versus 80% of maintenance from day 14 to 18), and some gilts received daily injections of insulin (0.6 IU live weight kg(-1)). The three experimental groups were H: 240% and no insulin (n=8); H-I: 240%+insulin (n=8) and L-I: 80%+insulin (n=7). On day 18, 4 h after insulin injection, plasma insulin was higher in insulin-treated than in untreated gilts and glucose concentrations were reduced more dramatically in L-I than in H-I gilts (P<0.05). Concentrations of IGF-I were lower in L-I than in other gilts (P<0.05) and plasma IGFBPs were not significantly affected by treatments. On day 19, the number of large follicles (> or = 5 mm) was not significantly influenced by treatments (19.4, 17.6 and 15.3 for H, H-I and L-I gilts, respectively). Insulin, IGF-I and IGFBP-2 levels in follicular fluids from large follicles did not differ between females whereas IGFBP-3 levels were lower in L-I than in H gilts (P<0.05) and intermediate in H-I gilts. Intrafollicular levels of glucose were higher in feed-restricted than in well-fed gilts (P<0.05). These results suggest that exogenous insulin does not restore final follicular growth impaired by acute undernutrition.

Animals↗

Stability of a perturbed Leslie model.

A small perturbation introduced in the stochastic Leslie model leads to a long-lived stable population in a region or parameter space where the stochastic model predicts the demise of the population. This somewhat surprising result is understood by considering a related model with a density-dependent sex ratio which exhibits similar features.

Birth Rate↗

Serum levels of intercellular adhesion molecule-1 in squamous cell carcinoma of the head and neck.

Soluble intercellular adhesion molecule-1 (s-ICAM-1) was measured in the sera of 131 patients with primary and 50 patients with recurrent squamous cell cancer of the head and neck (HNSCC). 30 patients with benign ear, nose and throat diseases served as controls. s-ICAM-1 levels in serum are high in patients with HNSCC, particularly in the advanced tumor stages (UICC IV). Highest levels can be measured at the time of tumor recurrence and locoregional lymph node metastases. The sensitivity (95% specificity) of s-ICAM-1 (cutoff-level: 473 ng/ml) is 4% at primary diagnosis and 12% for recurrent disease. A coefficient of correlation for s-ICAM-1 in combination with SCC, carcinoembryonic antigen and CYFRA 21-1 indicates that no correlation can be found of s-ICAM-1 compared with traditional tumor markers. Due to overlapping values in control and patient groups s-ICAM-1 is not suitable for a specific clinical use in HNSCC.

Antigens, Neoplasm↗

[Arteriovenous fistula with cardiac insufficiency disclosing kidney cancer].

A 66 year-old woman free of any coronary and valvular heart disease presented to our hospital with acute and severe congestive heart failure associated with increased blood flow-angiography showed an intraparenchymatous arteriovenous fistula of the left kidney and a kidney cancer. The patient was discharged after nephrectomy and complete heart recovery as assessed from the normality of the hemodynamic exploration of the right ventricle.

Aged↗

Ray and Jan reply.

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Journal Article↗

Size effects in Kauffman type evolution for rugged fitness landscapes.

Millions of sites are simulated in an NK fitness model of evolution and coevolution. We find a logarithmic size dependence of the number of hill-climbing iterations needed to reach a local fitness optimum (Nash equilibrium). We also check for chaotic behavior and determine the size of the damage clouds or avalanches. Random noise (simulated annealing) is shown to increase appreciably the fitness.

Algorithms↗

Dynamic light-scattering studies on the effect of heat and disinfectants on spores of Bacillus cereus.

The relative stability of spores of Bacillus cereus grown at three different temperatures was examined by using quasi-elastic light scattering (q.l.s.) in conjunction with turbidity and scanning electron microscopy (s.e.m.). Cultures grown at 20, 30 and 40 degrees C (BC20, BC30 and BC40 respectively) were compared in terms of (i) their effective hydrodynamic radius, rH, as determined from q.l.s. and (ii) their gross morphology, as determined from s.e.m. The effects of autoclaving at 121.1 degrees C on both these properties was also examined. We observed (1) that cultures BC20 and BC30 appeared to have similar values for rH, whereas that of BC40 appeared some 50% higher, and (2) BC40 had a correspondingly much lower heat resistance (its structural integrity was lost after about 20 min autoclaving, whereas that of BC20 and BC30 was retained even after 80 min autoclaving). These data were in good agreement with independent measurements of heat-resistance coefficients. Changes in the hydrodynamic radius, polydispersity (both using q.l.s.) and turbidity were monitored with time on addition of the disinfectants sodium hypochlorite and peracetic acid; again BC40 appeared to have a lower resistance.

Bacillus cereus↗