A computer based decision-making model for poultry inspection

In an attempt to develop a predictive model for poultry inspection at processing plants, a systems research design was developed to examine poultry population health dynamics from hatching to processing. Five cooperating Alabama poultry firms with 5 to 7 growers from each firm were identified to form the study unit. The farms were stratified to represent good, average, and poor producers. Via epidemiologic causal diagrams, variables with potential influence on poultry condemnation due to diseases were identified for hatchery, broiler, and processing subsystems. Field and/or laboratory data were generated for each study unit and for each variable. Using stepwise multiple regression and discriminant analysis, a predictor model with a multiple correlation coefficient (R) of 0.91 and multiple coefficient of determination (R2) of 0.82 was developed. A discriminant analysis model for classifying a flock into high or low condemnation group, using 0.1% to 2.0% as the demarcation line, was also developed. This latter model had overall correct classification probabilities ranging from 0.88 to 1.0. The 2 decision-making models were then computerized, using Beginner's All-purpose Symbolic Instruction Code (BASIC). On the day of processing, the grower provides the inspector with selected information, which is entered on a computer. Alternatives for scaled-down inspection or others are then systematically evaluated by the computer, and decision-making information is provided to the user.

In vivo endocytosis by bristle coated pits of protein tracers and their intracellular transport in the endothelial cells lining the sinuses of the liver. I. The endosomal disposition

The present observations describe the endocystosis and intracellular transport in the endothelial cells lining the sinuses of the rat liver and occurring 3 min after intravenous administration of two protein tracers: horseradish peroxidase and ferritin. Internalization of the proteins is exclusively by bristle coated pits followed by intracellular sequestration in bristle coated vesicles (diameter 90-210 nm). No other form of endocytosis is present in the endothelial cells of the liver sinuses. The bristle coated vesicles fuse with smooth membrane lined tubules (diameter 20-70 nm) termed transfer tubules. In this way the tracers are deposited into the lumens of the transfer tubules. The transfer tubules in turn fuse with preexisting electron-lucent endosomes which then receive the protein markers. In addition, direct fusion of bristle coated vesicles with endosomes occurs in limited measure. Bristle coated vesicles may fuse with other bristle coated vesicles while losing their clathrin coat, resulting in the formation of new endosomes which may enlarge through fusion with additional bristle coated vesicles or perhaps also with transfer tubules. The sinus endothelium also contains lysosomal vesicles which appear as dense bodies or multivesicular bodies. No protein tracers have been observed in these dense bodies at the time interval (i.e., 3 min) examined. Neither has a direct fusion between endosomes and lysosomes been found. The transfer tubules may be continuous with or may be derived from cisternae of the Golgi complex. No luminal continuity between transfer tubules and endoplasmic reticulum has been observed. The sinus endothelium also contains small bristle coated vesicles (30-40 nm) often attached to Golgi cisternae. These do not participate in the transport of endocytosed protein tracer and are in this respect functionally distinct from the large bristle coated vesicles derived from the endothelial plasmalemma. Serial sections show that there are extensive connections between the endocytic transport organelles: bristle coated vesicles, transfer tubules, and endosomes, possibly forming an intracellular luminal continuum.

In vivo endocytosis by bristle coated pits of protein tracers and their intracellular transport in the endothelial cells lining the sinuses of the liver. II. The endosomal-lysosomal transformation

The events leading to lysosomal activity in the sinus endothelium of the rat liver have been studied by means of intravascularly injected ferritin at time intervals ranging from 0.5 min to 1 hr after administration. From 6 min on, the dense body-type lysosomes contain ferritin. There are direct luminal communications of transfer tubules with these lysosomes. In time, there is a marked progressive increase in the number of ferritin-containing dense body-type lysosomes. No formation of lysosomes de novo nor a direct fusion of endosomes with lysosomes has been observed. Endosomes, however, continue to be formed as endocytosis continues. These observations are interpreted as indicating a transport of hydrolytic enzymes by the transfer tubules to the newly formed ferritin containing endosomes, which in this way are transformed into ferritin containing lysosomes. The ferritin-containing lysosomes increase considerably in size by fusing with each other. Continued endocytosis of ferritin leads to an increase of ferritin density in the dense bodies. This increase in particle density cannot be explained solely on the basis of transport by luminal fusion of the endocytic organelles, but requires an active transport mechanism. Administration of low doses of ferritin shows that the bristle coated pits of the sinus endothelium have a high degree of in vivo affinity for protein and that this endothelium must be considered to be an avid catabolic endocytic system.

Noninvasive flowmetry in vascular surgery: use of a noninvasive electromagnetic flowmeter

Using an in vitro model, the measurements made using a noninvasive electromagnetic flowmeter have been validated using standard square wave electromagnetic flowmetry. Clinically, the noninvasive electromagnetic flowmeter provides information as to the functional significance of vascular occlusive disease that is not available through other techniques, gives an accurate, quantitative measurement of the peak pulsatile blood flow through a limb, thus providing an index of tissue perfusion and therefore, the degree of involvement of the disease in the peripheral vascular system.

The structure of the sinus wall of the lymph node relative to its endocytic properties and transmural cell passage

The internal structure of cells lining the lymphatic sinus of the lymph node includes the presence of large bristle-coated vesicles, transfer tubules, and vesicular organelles for the uptake and intracellular disposition of endocytosed material. The lining cells of the sinuses phagocytose particulate material from the lymph in the same manner as the sinusoidal endothelium of the bone marrow takes up particulates from the blood and, thus, are similar in this respect to the endothelial lining of the bone marrow sinusoids. Transmission and scanning electron microscopic examination of the lymphatic sinus wall in rat lymph nodes show that the walls of the lymphatic sinuses are continuous and do not have permanent apertures allowing free communication between the extrasinusoidal and intrasinusoidal compartments in the lymph node. Migrating lymphocytes cross the lymphatic sinus wall intracellularly, i.e., through the body of the lining cell, by making a temporary migration pore, which closes after the cell has reached the lumen of the sinus. In addition there are sporadic aggregations of macrophages in transmural positions. The direction of their movement is unknown.

Entry of metastatic malignant cells into the circulation from a subcutaneously growing myelogenous tumor

The initial stage of metastasis formation, i.e., the entry of metastatic cells from a malignant subcutaneously growing myelogenous tumor into the circulation, was observed by means of transmission electron microscopy and scanning electron microscopy in Long-Evans rats. The transmural passage of malignant cells occurred through the walls of intact venules within the tumor. The malignant cell penetrated the endothelial cell body by making a temporary migration pore. The migration pore closed after the malignant cell entered the vascular lumen. The endothelial vascular lining remained continuous. The entry of malignant cells into the circulation was not the result of the general invasive and destructive properties of malignant tumor cells, but the consequence of a specific action of the tumor cells on the abluminal plasma membrane of the endothelium.

Applications of purification reactions for minimizing reaction-generated enzyme poisoning

A mathematical model has been employed to examine the interplay of reaction and mass transfer in immobilized enzyme systems involving reaction-generated enzyme poisions. Deactivation rates can be significantly reduced in some cases by catalyzing a purification reaction in which the poison is transformed into an innocuous substance. This conclusion in illustrated experimentally for reaction-generated H2O2 in a continuous-flow stirred slurry reactor containing glucose oxidase immobilized on activated carbon.

Destruction of circulating leukemia cells by phagocytosis in rats with myelogenous leukemia

Acute myelogenous leukemia was induced in outbred Long-Evans rats by iv injections of leukemia cells from a subcutaneous tumor of Shay myelogenous leukemia. In rats with this leukemia the peripheral white blood cell (WBC) counts varied from 2.4 to 700 X 10(9)/liter. No differences were found in the bone marrow of the rats with the high WBC counts and that of rats with low WBC counts. This observation could explain the large variations in the number of circulating leukemia cells caused by differences in cell proliferation or delivery of cells into the circulation. Massive phagocytosis of leukemia cells occurred in animals with low WBC counts (less than 12 X 10(9)/liter) but not in animals with high WBC counts (greater than 150 X 10(9)/liter). This phagocytosis was directed against circulating leukemia cells. The main phagocytes were Kupffer's cells of the liver and macrophages of the spleen parenchyma. In addition, phagocytosis occurred in the spleens and bone marrow by intravascular macrophages, which were derived from extravascular sites. The endothelium of the postcapillary venules of the lymph nodes participated in the phagocytosis of circulating leukemia cells while continuing to be the locus of lymphocytic return from circulation to lymphatic parenchyma. The factors underlying the differences in macrophage activity between the rats with high and low WBC counts were unknown.

On the development of the lymphoid follicles of the bursa of Fabricius

The structural features of the development of the bursa of Fabricius in white Leghorn chick embryos are depicted at carefully timed intervals during embryogenesis, with emphasis on the sequence of events between the ninth and twelfth days of incubation. The direction and character of the migration of lymphoid cell precursors and granulocytes from the intravascular space to intraepithelial sites, where the formation of the primitive lymphoepithelial nodule takes place, is demonstrated. The mechanism of the mode of migration of these cells through the stromal epithelial interface is described and illustrated with electron micrographs and their role in the development of the primitive lymphoid follicles is described and discussed.

Passage of red blood cells through the sinusoidal wall of the spleen

The migration of blood cells across the wall of splenic sinusoids has been studied by means of serial sections in rats inoculated with murine erythroblastosis virus (MEV). The sinusoidal walls of the normal spleen have no permanent openings. In the normal spleen, mature red blood cells and blood cells in the latest stages of maturation can be seen in diapedesis. The predominant form of transmural migration is intercellular. In MEV-inoculated animals, in which there is a vigorous erythroblastic proliferation, large numbers of erythroblasts are in transmural passage. Serial sections show that these cells migrate through the cytoplasm of the endothelial lining cells. On the basis of these observations, it is suggested that the transcellular mode of migration may be related to the delivery of newly formed red blood cells into the circulation while the intercellular mode may be part of the mechanism by which the spleen controls the removal of red cells from the circulation.