Slaughter performance of four different turkey strains, with special focus on the muscle fiber structure and the meat quality of the breast muscle.

The increase in human consumption of turkey meat and the shift in the poultry market from whole birds to further processed meat products increases the visibility of meat alterations (e.g., heterogenic color, drip loss, petechial hemorrhages) at retail. Changes in poultry meat quality have been related to the intensive growth of the current turkey strains. Considering this, the main objective of this investigation was to evaluate the meat quality and muscle structure of commercially available turkey strains with different growth properties but similar breast yields. Toms (n = 120) of 4 different turkey strains (British United Turkeys Big 6, Kelly Broad-Breasted Bronze, Kelly Wrolstad, Kelly Super Mini; n = 30 per strain) were reared in an experimental barn under similar environmental and feeding conditions and were slaughtered at 22 wk of age in a commercial slaughterhouse. The strains Big 6 and Broad-Breasted Bronze belong to the fast-growing (FG) turkey strain and the other 2 to the slow-growing (SG) turkey strain. The carcass weights, as estimated by video imaging, differed significantly (P < 0.05) between the SG and FG groups. The breast yields (percentage of carcass weight) of the investigated strains were similar. Except for the significantly (P < 0.05) greater protein concentration in the musculus pectoralis superficialis of the SG birds, the musculus pectoralis superficialis had nearly similar fat and ash contents. Plasma lactate concentrations were similar in the investigated turkey strains but the creatine kinase activities were greater in the FG turkeys at the time of slaughter. Determination of the different meat quality parameters [pH, electrical conductivity, color (L a b), drip loss, shear force] did not result in clear differences between the SG and FG turkey strains. There were larger muscle fibers in the FG in comparison with the SG strains, but no differences could be determined in the capillary density and incidence of degenerated or giant fibers, except for a higher rate in the Wrolstad strain. The present results are contradictory to the opinion that turkeys with faster growth have worse meat quality.

Fluid secretion by isolated Malpighian tubules of Drosophila melanogaster Meig.: effects of organic anions, quinacrine and a diuretic factor found in the secreted fluid.

Para-aminohippuric acid (PAH, 0.2 and 1 mmol l(-)(1)) had no effect on the basal fluid secretion rate (FSR) of isolated Malpighian tubules of Drosophila melanogaster Meig. and did not affect stimulation of the FSR induced by adenosine 3',5'-monophosphate (cAMP). Phenol Red (phenolsulphonphthalein, PSP; 0.5 and 1 mmol l(-)(1)) slowed the FSR and abolished stimulation of the FSR by cAMP. Diodrast (1 mmol l(-)(1)) slightly, but significantly, reduced the FSR and greatly reduced the stimulation of the FSR normally provoked by cAMP and by the 3',5'-monophosphates of guanosine (cGMP), inosine (cIMP) and uridine (cUMP). However, stimulation of the FSR by the 3', 5'-monophosphate of cytidine (cCMP) was little affected by diodrast. Probenecid (0.2 or 1 mmol l(-)(1)) consistently stimulated the FSR, on average by approximately 25 %, but did not markedly inhibit the subsequent stimulation of the FSR by cAMP, cGMP or cIMP. However, the FSR of tubules stimulated by cGMP was temporarily lowered by probenecid. Quinacrine (0.1 mmol l(-)(1)) slowed basal FSR by an average of approximately 30 %, but subsequent stimulation of the FSR by cAMP was not noticeably affected. Both 0.1 mmol l(-)(1) cAMP and 1 mmol l(-)(1) probenecid stimulated adenylate cyclase activity in extracts of Malpighian tubules, but cIMP, cGMP, cUMP and diodrast were without effect in this regard. Uptake of radioactivity from a solution containing 500 nmol l(-)(1) [(3)H]cAMP and 9.5 micromol l(-)(1) cAMP was reduced by more than 90 % by 1 mmol l(-)(1) PSP, by approximately 40 % by 0.2 mmol l(-)(1) probenecid, by 36 % by 1 mmol l(-)(1) diodrast and by 30 % by 1 mmol l(-)(1) PAH. Neither 0.01 mmol l(-)(1) ouabain nor 0.1 mmol l(-)(1) quinacrine affected the uptake of [(3)H]cAMP by the Malpighian tubules. Fluid secreted by isolated Malpighian tubules of Drosophila melanogaster contains a factor that stimulated the FSR on average by approximately 50 %. The presence in the secreted fluid of cGMP at a concentration of 8.3 micromol l(-)(1) did not explain the stimulatory effect on FSR. These results support the existence of a carrier-mediated uptake of cyclic nucleotides into the Malpighian tubules of Drosophila melanogaster, possibly involving a multispecific transporter.

[Retroperitoneoscopy--a new era]. / Retroperitoneoskopie--nová éra.

Retroperitoneoscopy is a minimal invasive surgical technique enabling the diagnostics of the disease, as well as operative treatment of retroperitoneal organs. It is a very promising method especially for urologist, but of interest for general, vascular surgeon or gynecologist. The method is known since the end of sixties. Its routine introduction was enabled by technical advancement of laparoscopic surgery.

Nuclear events after activation of CD4+8+ thymocytes.

Functionally mature T cells respond to stimulation via the Ag receptor by secretion of IL-2 and/or other lymphokines and by proliferation. However, immature CD4+8+ thymocytes do not secrete IL-2 or proliferate in response to stimulation. We have analyzed murine thymocyte populations enriched for CD4+ and CD4+8+ cells as well as the functionally mature CD4+ lymphoma C6VL-B and the CD4+8+ lymphoma 1010 for their ability to express mRNA related to early products of T cell activation signals. When stimulated with the calcium ionophore (Ionomycin) plus PMA, all the cells, regardless of their phenotype, accumulated abundant levels of c-myc mRNA. However, in contrast to the CD4+ thymocytes and C6VL-B, which accumulated abundant levels of IL-2 transcripts, neither the normal CD4+8+ thymocytes nor 1010 expressed IL-2 mRNA before or after stimulation. We have also examined these cells for the presence of the murine equivalents of two nuclear DNA-binding factors, NFAT-1 and NFIL2-A, which have been shown to be involved in IL-2 gene expression in human T cells. Our results indicate: 1) NFIL-2A binding activity is constitutively expressed in both CD4+ and CD4+8+ thymocytes and lymphomas and 2) NFAT-1 binding activity is readily detected in CD4+ thymocytes and C6VL-B, but is detected in very minimal amounts in populations enriched for CD4+8+ thymocytes and in 1010 upon activation. These results suggest that the failure of CD4+8+ thymocytes to express IL-2 mRNA upon stimulation may be in part due to the lack of inducibility of NFAT-1 binding activity, and that functional maturation of this population might be associated with acquisition of the ability to induce NFAT-1 activity.

Consideration of the anterior cruciate ligament injury in skiing.

The anterior cruciate ligament (ACL) injury of the knee is a common ski injury. At a typical ski area clinic in Wyoming, an average of one per day is diagnosed over the 120-day ski season. Other ski clinics report a similar incidence of ACL injuries. In view of the 570 registered ski slopes in the United States, the ACL injuries occur at epidemic proportions. Under consideration are causal factors involved in the typical skier's ACL injury, such as recent evolutions in skiing techniques, boot styles, the skier's environment, and the anatomic considerations relating to body mechanics that place the ACL in a position of compromise in the intercondylar notch. Clear identification of the mechanism of ski injury of the ACL is difficult. As the significant causative factors become identified, and with the stimulation of further interest and research, there is some promise for prevention in the future.

The absence of an arterial pressure effect on filtration by perfused glomeruli of the hagfish, Eptatretus stouti (Lockington).

Single renal corpuscles of hagfish were perfused with a Ringer solution containing Ficoll 70 to simulate the colloid osmotic pressure of hagfish plasma. Simultaneous measurements were made of single glomerulus filtration rate (SGFR), perfusion pressure and the pressure in a vessel of the renal vasculature. The results confirm that SGFR is independent of pressure in the glomerular capillaries (PGC). The results also suggest that flow through glomeruli and SGFR are closely linked. Studies of the pressures in glomerular capillaries during periods when the perfusion rate was varied indicate that PGC reflects the area of the active capillaries and the rate of perfusion. Therefore, in the hagfish, PGC appears to be an effect of factors that cause glomerular filtration, not the main cause of that process.

Hydrostatic pressures in glomeruli and renal vasculature of the hagfish, Eptatretus stouti.

Hydrostatic pressures in the renal vasculature of hagfish have been studied. Estimates of the blood colloid osmotic pressure (COP) have been made. In blood vessels supplying the renal corpuscles, the average hydrostatic pressure is about 1 kPa. The average hydrostatic pressure falls to a value of 0.04 kPa within the postcardinal vein efferent to the renal corpuscle. Within the glomerular capillaries the hydrostatic pressure averages 0.21 kPa. Since the blood COP averages about 1.4 kPa, it is clear that glomerular filtration in the hagfish is not underlain by the hydrostatic pressure of the arterial pulse. In some blood vessels efferent to the renal corpuscles, hydrostatic pressure may be as high as in the afferent supply. Evidence is presented that the glomerular capillaries are shunted by this high pressure vascular pathway.

Use of cathartics in toxic ingestions.

Cathartics are commonly recommended for treatment of ingestion of toxic substances. Literature review shows little evidence of efficacy of this practice. Published reports of morbidity are limited to pediatric patients experiencing electrolyte imbalance. Our survey of the members of the American Board of Toxicology, as well as our literature review, form the basis for suggesting catharsis of most patients when treating toxic ingestions. However, caution must be used in very old or very young patients, in those with preexisting renal disease or ingestion of nephrotoxic substances, in corrosive ingestions, in patients with recent bowel surgery or absent bowel sounds, and in patients with hypertension or congestive heart failure. Oil catharsis is not recommended.

Rheumatic fever situation in Czechoslovakia with special reference to long-term prognosis for rheumatic carditis.

In a prospective study (1961-1972) the incidence of rheumatic fever (RF), development of rheumatic heart disease (RHD) and penicillin prophylaxis efficacy were investigated in 300 000 children and 70 000 adults. Only patients whose index attack met the modified Jones' criteria were included; all were enrolled in a prophylaxis programme (i. m. benzathine-penicillin). The RF incidence decreased from an initial 61.2 attacks per 100 000 in children and 42.9 in adults to below 10 by 1969 and remained low thereafter. In total, 541 children (209 with carditis) and 176 adults (108 with carditis) were followed up for 5.5 years (average) after an index attack. At final examination, no valvular involvement was detected where previous attacks had been without clinical carditis. Patients studied from time of the primary attack with carditis (211) had a very favorable prognosis: only up to 3.5% had developed a moderate to severe heart lesion by the end of the study. However, of 68 adult patients followed up only from the time of recurrence with carditis and often having had a prolonged rheumatic history: 23.5% had a moderate to severe heart lesion and a further 20.6% had died of RHD by the end of the study. Prophylaxis efficacy calculated as a cumulative attack-recurrence rate per 100 patients and over a 5-year interval was 2.72 in protected as against 64.75 in unprotected children (mostly failing to comply with prophylaxis); in adults, the respective values were 1.3 and 24.92. The prevalence of serious residual RHD may be expected to decrease substantially in the future, starting with the younger age groups.

Factors affecting glomerular function in the pacific hagfish Eptatretus stouti (Lockington).

Single glomerulus filtration rate in Eptatretus stouti averaged 20.3+/-2.13 (S.E.M.) nl min(-1). Single glomerulus glomerular filtration rate (GFR) could be correlated with arterial pressure when arterial pressure exceeded about 4 cm H2O. Glomerular filtration was affected by postglomerular resistance brought about by alteration of the volume of urinary spaces. Filtration undoubtedly plays a role in glomerulus function. However, average colloid osmotic pressure (COP) of the plasma is almost double the average hydrostatic pressure in the segmental arteries serving the glomeruli. The COP of glomerular fluid is essentially nil, therefore it is difficult to see how pressure filtration alone can account for primary urine formation. When single glomeruli were perfused with colloid-containing Ringer at pressures within the normal range of blood pressures, GFR was within the normal range. GFR was related inversely to the colloid osmotic pressure of the perfusion Ringer. Colloid entered the urine during perfusion. However, in only a few instances did this result in conditions favourable to pressure filtration. To assess the role of active processes in glomerular filtration, chemical inhibitors were added to the perfusion Ringer. Amiloride, acetazolamide, cyanide, 2-deoxy-D-glucose, iodoacetate and ethacrynic acid were without marked effect on glomerular filtration. Ouabain and dinitrophenol markedly reduced GFR; inhibition was probably not due to indirect effects upon the renal vasculature.

Ultrastructural tracer studies on the permeability of the Malpighian tubule of the pill millipede, Glomeris marginate (Villers).

The electron-dense tracers ferritin, and iron-dextran, and the protein horseradish peroxidase, have been used to investigate the ultrastructural basis of permeability in the upper and lower segments of the Malpighian tubules of Glomeris marginata. All these materials were able to cross the basal lamina and enter the tubule lumen of the upper segment, and it was established that horseradish peroxidase was able to enter the channels which interrupt the apical junctions. In the upper segment, ferritin, iron-dextran, and horseradish peroxidase are taken up and accumulated within intracellular vesicles. In the lower segment ferritin and iron-dextran enter the cells but become generally distributed over the cytoplasm, as well as entering membrane-bounded vacoules. The behaviour of horseradish peroxidase could not be assessed by owing to the presence of endogenous peroxidase activity in the cells. After fixation by direct application of glutaraldehyde to the undissected tubules, the extracellular spaces contained large numbers of membrane-bounded vesicles. The significance of these observations is discussed in relation to the physiological activities of the tubules.

Ultrastructural studies on the Malpighian tubule of the pill millipede, Glomeris marginata (villers).

Ultrastructural studies on the Malpighian tubules of Glomeris marginata (Villers) reveal considerable morphological differences between the upper, fluid secreting, segment, and the lower segment which is at present of unknown function. Previous reports have shown that the upper tubule has a high permeability to compounds of high molecular weight. This may be accounted for by the fact that the epithelium shows very extensive intercellular spaces which are linked directly to junctions apparently specialised to provide a low resistance extracellular pathway between the haemocoel and the tubule lumen. Histochemical studies on the localisation of phosphatase enzymes reveal intracellular vesicles with acid phosphatase activity. The basal labyrinth of the lower tubule exhibits considerable alkaline phosphatase activity which is apparently identical in location to the enzyme revealed by two different ATPase localisation techniques.