Neuron-glia cell adhesion molecule (Ng-CAM) expression in the chick embryo spinal cord: observations on the earliest developing intersegmental interneurons

The pattern of expression of the neuron-glia cell adhesion molecule (Ng-CAM) among the presumptive intersegmental interneurons in the early chick embryo spinal cord (stage 14-19) was examined using whole-mount and cryostat preparations double-stained with anti-Ng-CAM antibody and a neuron-specific anti-beta-tubulin antibody. In brachial segments, primitive longitudinal cells (PL-cells), located in the ventrolateral region of the spinal cord, express Ng-CAM both on their cell bodies and longitudinally growing axons, beginning at Hamburger-Hamilton stage 15 (embryonic day (E) 2.5). Shortly thereafter, at stage 16, circumferential cells (C-cells), composed of associational and commissural interneurons in the dorsolateral and lateral region of the spinal cord begin to express Ng-CAM both on their cell bodies and their axons which project ventrally along the lateral surface of the spinal cord. In the following stages. PL-cells express Ng-CAM strongly and begin to fasciculate to form a longitudinal fascicle in the ventrolateral marginal region of the spinal cord. C-Cells either extend their Ng-CAM-positive axons ventrally without fasciculation to join the Ng-CAM positive ipsilateral longitudinal fascicle at stage 17 (which has already been formed by PL-cell axons), or they cross the midline to join the Ng-CAM positive contralateral longitudinal fascicle after growing through the floor plate at stage 19. By stage 19, cell bodies and proximal segments of the C-cell axons exhibit decreased Ng-CAM expression, whereas the distal segment of these axons, including growth cones, strongly express Ng-CAM. Many contacts were observed between Ng-CAM-positive growth cones and axons in the ventral region of the spinal cord, both within the longitudinal fascicle and the floor plate region, suggesting the involvement of Ng-CAM in neurite-neurite interactions.(ABSTRACT TRUNCATED AT 250 WORDS)

Visible spectroscopic technique for flowing erythrocytes in capillary

An optical spectroscopic system for determining the rate of oxygen release from flowing erythrocytes in microvessel is developed. The apparatus consists of following units attached to an inverted microscope. 1) A scanning spectrophotometer, equipped with a grating and a photon counter, was connected to an eyepiece of the microscope through a narrow light-guide, as to obtain the absorption spectrum (wave length range: 450-650 nm) of a focused spot (phi = 7 microns). 2) The velocity of erythrocyte flow was measured by dual-spots cross-correlation method, using two photomultipliers (connected to A/D converter and microcomputer) with two light-guides inserted into another eyepiece. 3) The diameter of vessel was estimated from digitized video-images, using a color image-processor. The ability of the apparatus was tested with (a) hemoglobin solution, (b) flowing erythrocyte suspension and (c) capillaries of rat mesentery. The rate of oxygen release through the vessel wall was calculated.

Identification of early developing axon projections from spinal interneurons in the chick embryo with a neuron specific beta-tubulin antibody: evidence for a new 'pioneer' pathway in the spinal cord

The early development of interneurons in the chick embryo spinal cord was studied using a monoclonal antibody against a neuron-specific beta-tubulin isoform. Early developing interneurons were divided into two cell groups on the basis of their location and the pattern of growth of their axons. One group is composed of cells that establish a primitive longitudinal pathway (PL-cells), whereas the other group contains cells constituting a circumferential pathway (C-cells). The onset of axonal development in both cell groups occurs at stage (st.) 15 (embryonic day, (E), 2) in the branchial segments, which is prior to axonogenesis of motoneurons. PL-cells develop in the region between the floor plate and the motoneuron nucleus. Their axons are the first neuronal processes ('pioneer axons') to arrive in the ventrolateral marginal zone and they project both rostrally and caudally to establish a primitive longitudinal association pathway at the ventrolateral surface of the neural tube. This pathway is formed before axons of C-cells arrive in the ventrolateral region. The first C-cells are initially located in the most dorsal portion of the neural tube, whereas later appearing C-cells are also located in both intermediate and ventral regions of the neural tube. The axons of C-cells project ventrally, without fasciculating, along the lateral border of the neural tube. Some of their axons enter the ipsilateral ventrolateral longitudinal pathway at st. 17. We often observed apparent contacts and interactions between preexisting axons of PL-cells and newly arriving axons of C-cells. The axons of commissural C-cells first enter the floor plate at st. 17 and cross the midline at st. 18. Axons of C cells begin to join the contralateral ventrolateral longitudinal pathway at st. 18+ to st. 19. In the floor plate region, contacts between growth cones and axons were often observed. However, axons in the floor plate at these stages were not fasciculated. These observations establish the timing and pattern of growth of axons from two specific populations of early developing interneurons in the chick spinal cord. Additionally, we have identified an early and apparently previously undescribed 'pioneer' pathway that constitutes the first longitudinal pathway in the chick spinal cord.

Contribution of glycoproteins to fibrinogen-induced aggregation of erythrocytes

The contribution of membrane glycoproteins to the velocity of fibrinogen-induced erythrocyte aggregation was examined using a rheoscope combined with a video camera, an image analyzer and a computer. The structure of glycoproteins was modified with proteolytic enzymes, trypsin or alpha-chymotrypsin. (1) Mild enzymatic treatment of erythrocytes decreased the velocity of erythrocyte aggregation, but more intense treatment increased the velocity remarkably. (2) The erythrocyte aggregation was affected not only by the density of surface negative charge of erythrocytes, but also by the structural changes of glycoproteins. (3) Erythrocyte deformability and the morphological characteristics were not altered by these enzymatic treatments. The physiological significance of glycoproteins of erythrocyte surface for the survival of erythrocytes and for the suspension stability of blood was discussed.

Erythrocyte rheology

Two main subjects of erythrocyte rheology, deformation and aggregation, are discussed in detail, on the basis of biochemical structure. The close relationship between the life span (or cell aging) and the rheology of individual erythrocytes is also briefly described. A currently important problem is emphasized, that is, the molecular aspect of the dynamic cytoskeletal structure and the mechanism of its regulation. This concerns not only the rheological function and the survival of circulating erythrocytes, but also the pathophysiology of abnormal erythrocytes.

Temperature effect on oxygenation and metabolism of perfused rat hindlimb muscle

The effects of temperature on oxygenation and metabolism in perfused rat hindlimb was studied at 35 degrees C and 15 degrees C. Oxygenation of myoglobin and oxidation of cytochrome aa3 in the thigh (quadriceps) muscle were estimated from the difference spectra measured with a rapid-scanning spectrophotometer. Simultaneously, oxygen uptake and release of lactate and pyruvate were measured. (1) In hypothermia, glycolysis played a major role in energy metabolism even though Cyt aa3 was maintained in a more oxidized state than in normothermia. (2) P50 of myoglobin in perfused rat hindlimb was 5.0 mmHg at 35 degrees C, 2.3 mmHg at 25 degrees C and 1.1 mmHg at 15 degrees C. The delta H degree was -13.0 kcal/mol. (3) When about 30% of myoglobin was deoxygenated at both 35 degrees C and 15 degrees C, the oxygen uptake started to decrease and lactate release increased. (4) At 35 degrees C, the oxidation level of cytochrome aa3 was same as the oxygenation level of myoglobin. At 15 degrees C, however, the oxidation level of cytochrome aa3 was clearly higher than the oxygenation level of myoglobin. The oxygen uptake at 15 degrees C was about one third that at 35 degrees C. In conclusion, in order to maintain the aerobic condition of cytochrome aa3 in mitochondria of rat skeletal muscle, a tissue oxygen tension higher than 12 mmHg at 35 degrees C, and higher than 3 mmHg at 15 degrees C is required.

Facilitated transport of oxygen through hemoglobin solutions

A method for quantitative analysis of hemoglobin color to estimate the oxygen saturation was developed. The method uses an image-input and -processing system composed of a 3-tube video camera and a digital image analyzer. When the system is connected to a microscope, the facilitated diffusion of oxygen in hemoglobin solutions can be observed and analyzed in a position-sensitive manner. The results led to a new transport model expressed as: J = k'CY/d, where J is the oxygen flux, C is the hemoglobin concentration, Y is the oxygen saturation of hemoglobin, d is the distance between the entrance of oxygen and the diffusion front, and k' is a constant.

Rheological properties of erythrocytes in recombinant human erythropoietin-administered normal rat

Recombinant human erythropoietin [rhEPO (180 iu/micrograms); 1 or 10 micrograms polypeptide equivalent/kg] was intravenously administered daily to 6-week-old normal rats for 1 week. Rheologically, (1) blood viscosity at shear rate of 40-380 s-1 increased in a manner entirely dependent upon the haematocrit, (2) no change in erythrocyte deformability was detected by high shear rheoscopy, and (3) the velocity of rouleau formation in autologous plasma (at 7.5 s-1) decreased. Haematologically, rhEPO administration induced considerable polycythaemia with reticulocytosis in a dose-dependent manner, accompanying increased cell volume and decreased intracellular haemoglobin concentration, thus the density distribution of erythrocytes shifted towards low specific gravity. Plasma viscosity and plasma protein composition were unaffected by rhEPO-administration. In erythrocyte metabolism, no drastic alteration in the level of 2.3-DPG or ATP was detected.

[New approach for unresectable primary liver cancer--intra-arterial combination chemotherapy during and after operation with local injection of ethanol]

From 1976 to 1988, hepatic arterial infusion chemotherapy was performed in 52 patients with unresectable hepato-cellular carcinomas. Forty-nine (94%) out of 52 patients were stage III or stage IV. Thirty-five patients underwent continuous infusion of 5-FU and MMC employing chronometric infusion pumps. Mean survival of this group was 9 months. Six patients survived more than 12 months; the longest survivor died of different causes 40 months after surgery. Another patient lived for 30 months. In 10 patients, hepatic arterial ligation was performed in combination with infusion chemotherapy in the hepatic artery. Mean survival of these patients was 14 months. Four out of the 10 patients survived over 12 months. Recently, in 7 patients whose liver tumors were less than 4 cm in diameter and/or whose tumors were multiple and had liver disfunction, ethanol injection into the tumors during laparotomy was performed in combination with hepatic arterial infusion chemotherapy. In these 7 patients, an injection port system was implanted subcutaneously for intermittent infusion chemotherapy of MMC + 5-FU and ADM + lipiodol. Mean survival in this group was 14 months. One of 7 patients died 21 months after operation, but the others are alive at this writing. Five of these 6 patients have survived more than 12 months. AFP levels decreased in 3 patients after these treatments. In one case, AFP decreased to normal range for 18 months. These results suggested that intraoperative ethanol injection therapy into the tumors combining with hepatic arterial infusion chemotherapy may be of value for unresectable smaller liver carcinomas, since this method is technically easy and can assure injection of ethanol into the tumors during laparotomy.

Near UV-induced free radicals in ocular lens, studied by ESR and spin trapping

An electron spin resonance (ESR) study on UV-photolysis of human and canine lens nuclei was carried out at room temperature. (1) At least two kinds of free radical signals, a narrow signal and a broad one, were detected at around g = 2.004. The latter is similar to that observed upon irradiation of a model solution containing both tryptophan and cysteine. (2) Two spin adducts were detected upon irradiation of canine lens in the presence of a spin trapping reagent (DMPO, 5,5-dimethyl-1-pyrroline N-oxide), i.e. a spin adduct of sulphur-centered radical (most likely glutathione thiyl radical) and the protonated adduct of solvated electron (presumably due to photo-ionization of tryptophan). (3) A tentative and simplified reaction mechanism of UV-induced damage is discussed on the basis of these observations.

[Therapeutic effect of interferon-alpha on hairy cell leukemia]

Hairy cell leukemia (HCL) is characterized by slow proliferation of special mononuclear cells. Although splenectomy has been evaluated to be the most effective traditional treatment for HCL, the response of patients to splenectomy is not necessarily satisfactory. Recently, the treatment of HCL with Interferon-alpha has been reported to be effective, and we report a female case of HCL who showed marked improvement in her hematological findings with this therapy.

[An anesthetic experience with a patient with ornithine transcarbamylase deficiency]

We report an anesthetic experience with ornithine transcarbamylase deficiency. The patient was 26 years of age who underwent open biopsy of the liver for a definitive diagnosis. OTC deficiency is an X-linked disorder of urea cycle. One of the anesthetic problems is how to control the blood ammonia level resulting in neurological damage which occurs following anesthesia and surgery. Recently it has been advocated that benzoate is effective to prevent hyperammonemia in patients with OTC deficiency. As patients with this disease are frequently complicated with hepatic dysfunction, anesthetics which may cause hepatic damage such as halothane should be avoided.

Phase II clinical trial of high-dose recombinant human tumor necrosis factor

Based on a phase I study in 1986, 22 patients have been entered in a phase II study of high-dose human tumor necrosis factor (rH-TNF) since May 1987. Of these patients, 18 are evaluable at present, 2 are still under investigation, and 2 have dropped out. All had advanced stages of cancer (9 soft-tissue sarcomas, 3 melanomas, 5 hypernephromas) and inclusion in the study was ethically acceptable (informed consent). The daily dose of rH-TNF was 15 x 10(5) units/m2, escalated to 21 x 10(5) units/m2 (683-956 micrograms/m2 every week; range 1-6 cycles). Additional prophylactic ketoprofen administration was carried out. Of the 18 evaluable patients, 4 responded with no change (2/4, clinical improvement) and 14 showed progressive disease. The main toxicities observed were hypotension (decrease in systolic blood pressure, 21-60 Torr), leukocytosis, increases in ALAT/ASAT (WHO grade 0-4), fever (WHO grade 1-2), chills (mild to moderate), neurotoxicity (WHO grade 0-2), and nausea/vomiting (WHO grade 0-3).

Oscillatory deformation of human erythrocytes in sinusoidally modulated shear flow

The red cell deformation under oscillatory shear stress was studied. Shear stress was sinusoidally modulated between 8 and 32 dyn/cm2, thus, the extent of cellular deformation altered sinusoidally. At a low modulation frequency (less than 1.8 Hz), intact red cells perfectly responded to the shear stress applied on cells, and they could deform as much as the deformation in stationary shear flow. Above 2 Hz, the cellular deformation could not follow changes in shear stress along up-phase in the shear stress cycle. As decreasing the intracellular hemoglobin concentration, the cellular response to oscillatory shear stress became better. Treatment of cells with low concentrations of diamide impaired the response of intact cells to oscillatory shear stress, but unaffected the response of partially hemolyzed cells. These data suggest that the cellular response to oscillatory shear stress is determined by the cytoskeletal structure and the intracellular viscosity.

Effect of pH on the velocity of erythrocyte aggregation

The effect of pH on the velocity of aggregation of human erythrocytes was quantitatively examined with a rheoscope combined with a video-camera, an image analyzer and a computer, in relation to the morphological changes of erythrocytes and their aggregates. (i) With increasing pH of the medium, the velocity of erythrocyte aggregation increased. (ii) The rouleaux formed at high pH were longer in shape and more stable against the increase of shear rate than those formed at low pH. (iii) With increasing pH, the diameter of erythrocyte increased, the (maximum) thickness decreased, and the cell volume decreased. The pH dependency of erythrocyte aggregation may be mainly due to the morphological change of erythrocytes, and partly due to the changes of erythrocyte deformability and of interaction with macromolecules.

Erythrocyte aggregation as a determinant of blood flow: effect of pH, temperature and osmotic pressure

The effect of pH, temperature and osmotic pressure on velocity of erythrocyte aggregation was quantitatively examined with a rheoscope combined with a video-camera, an image analyzer and a computer, (a) in an artificial medium containing fibrinogen and albumin and (b) in diluted autologous plasma. (1) With increasing pH of the medium, the velocity of erythrocyte aggregation increased. (2) The velocity of erythrocyte aggregation in the artificial medium increased as the temperature rose. However, in 70% autologous plasma the velocity was minimum at 15-18 degrees C, increasing both above and below this temperature (above 30 degrees C, the velocity saturated). (3) The velocity of erythrocyte aggregation decreased in hypotonic medium, while it increased in hypertonic medium (at osmotic pressures higher than 400 mOsm, the velocity decreased). The mechanism of erythrocyte aggregation is discussed with special reference to the morphological changes produced by pH, temperature and osmotic pressure, and the implications of the phenomena for oxygen transport to tissues in (patho)physiological situations are considered.

[The possibility of surgery for aged patients with gastric cancer]

The possibility of surgery for aged patients with gastric cancer has been studied. Of 484 cases who underwent a gastrectomy, patients 70 years of age or over amounted to 86 (20%). The postoperative mortality rate for these aged patients was 3% and the postoperative mortality rate with hospital deaths added from other causes than operative deaths was 7%. The postoperative mortality rate of aged patients who underwent total or proximal subtotal gastrectomy improved during the period between 1975-1983 compared with the period between 1967-1974. In the second period, there were no deaths among aged patients who underwent an R3-operation and/or a combine operation. This fact shows that operative procedures have become safer for aged patients.

Effect of temperature on the velocity of erythrocyte aggregation

The velocity of the aggregation of human erythrocytes was examined in the range of 5-43 degrees C with a rheoscope combined with a video camera, an image analyzer and a computer. (1) With increasing temperature, the velocity of erythrocyte aggregation induced by fibrinogen, immunoglobulin G and artificial macromolecules (dextran of 70 kDa and poly(glutamic acid) of 50 kDa) increased. However, the relationship between the velocity of erythrocyte aggregation and the temperature was different among these macromolecules. (2) In 70% autologous plasma, the velocity of erythrocyte aggregation was minimum at 15-18 degrees C, and increased at both higher and lower temperatures. (3) The shape of erythrocyte aggregates in 12 mumol/l fibrinogen (containing 770 mumol/l albumin) and in 70% autologous plasma was dependent on temperature: three-dimensional below 15-18 degrees C and one-dimensional (mainly rouleaux) above 15-18 degrees C. However, the shape of aggregates in 27 mumol/l immunoglobulin G (containing 770 mumol/l albumin) was three-dimensional in all temperature ranges. (4) The temperature dependency of erythrocyte aggregation was discussed in terms of the changes of medium viscosity, of erythrocyte properties and of bridging macromolecules.

Fibrinogen-induced erythrocyte aggregation: erythrocyte-binding site in the fibrinogen molecule

The effect of fibrinogen and fibrinogen-derived products on the velocity of rouleau formation of human erythrocytes was quantitatively examined with a rheoscope combined with a video-camera, an image analyzer and a computer. (i) The velocity of rouleau formation by naturally occurring low-molecular-weight fibrinogen of 305 kDa and by desialylated fibrinogen was the same as that by native fibrinogen of 340 kDa. (ii) Concerning fibrinogen degradation products by plasmin, the velocity of rouleau formation decreased upon going from fibrinogen greater than fragment X greater than fragment Y (the ratio of molar concentration of fibrinogen, fragment X and fragment Y for giving a certain velocity of rouleau formation was approx. 1:2:5). The effect of fragments X and Y on the fibrinogen-induced rouleau formation was additive. (iii) Fragments D and E could not induce rouleau formation and did not affect the fibrinogen-, fragment X- and fragment Y-induced rouleau formation. (iv) Fibrinopeptides A and B and artificial tetrapeptides (Gly-Pro-Arg-Pro and Gly-His-Arg-Pro) did not affect the fibrinogen-induced rouleau formation. (v) The possible erythrocyte-binding site in fibrinogen molecule for leading to rouleaux was proposed to be in A alpha-chain (probably, around residues No. 207-303) near the terminal domain of the trinodular structure of fibrinogen.

Ventricular pressure-heart rate product before induction of ischemia as a determinant of the reperfusion-induced accumulation of calcium within myocardium

Using the product of heart rate (HR) and left ventricular developed pressure (LVP) as a measure of the total mechanical energy required for contraction (TMEFC), experiments were performed with isolated perfused heart preparations of the guinea pig to establish the importance of TMEFC before induction of ischemia for induction of calcium accumulation within ischemic reperfused myocardium. Two calcium antagonists, diltiazem and nicardipine, and prazosin produced a dose-related suppression of the calcium accumulation when given prior to induction of ischemia (except for the highest dose of nicardipine), while they were ineffective when given only during the period of reperfusion, and the suppression was found to be closely correlated with the decrease in HRxLVP before induction of ischemia. The failure of the highest dose of nicardipine to suppress calcium accumulation (while producing a dose-related decrease in HRxLVP) was not associated with an increase in cyclic AMP. These findings are compatible with the idea that TMEFC before induction of ischemia is a prime determinant of calcium accumulation within the ischemic reperfused myocardium.