Notochord and spinal malformations

Fourteen spinal malformations were found in 328 spontaneously aborted human embryos and fetuses. Of these, 13 were investigated histologically and histomorphometrically and compared with 47 age- and stagematched normal specimens to document any possible relationship between spinal and notochordal malformations. Although six notochordal malformations, such as bifurcation, were found in 14 spinal malformations, the respective sites did not correspond. Abnormality of notochordal tissue - such as degeneration and delayed development, which was observed in nine of 14 spinal malformations - was not restricted to the site of the spinal malformation. Moreover, tissue changes responsible for spinal malformations usually did not occur in direct contact with the notochord. On the other hand, malformed notochords were found in normal specimens. We therefore were unable to confirm in human specimens that notochordal abnormalities induce spinal malformations, a fact well established in lower vertebrates.     

Ileocecal resection in neonates a follow-up study

From 1977 to 1982 ileocecal resection was done in five neonates admitted to our pediatric surgical units. The growth and development of these infants were examined and comparisons were made with age matched controls. Two who had undergone ileocecal resections had a slight diarrhea. Physical examination, hematology and blood chemistry, including serum levels of rapid turnover proteins, were all within the normal ranges. Significant differences between data on these patients and the controls were not noted. Our findings indicate that ileocecal resection with less extensive ileal resection can be done in neonates as an adequate nutrition is physiologically feasible.     

Continuous measurement of left ventricular volume in rabbit,using a two-electrode catheter

Summary We developed a device for monitoring instantaneous left ventricular (LV) volume using an alternating-current excitation two-electrode conductance catheter. Instantaneous conductance between a pair of electrodes was amplified by a noninverting circuit. The level of conductance was linearly related to changes in blood volume from 0.8 to 2.0ml in a latex balloon (r ² = 0.95), and to changes in blood volume from 0.4 to 2.2ml in a post-mortem rabbit left ventricle (r ² = 0.99). The difference between the maximal and minimal conductance of the LV in situ during a cardiac cycle was closely correlated with changes in stroke volume, measured by an electromagnetic flow probe (r ² = 0.97). The endsystolic pressure-conductance relation (ESPCR) was highly linear (r ² = 0.92). Changes of the slope (Ees) of the ESPCR correlated directionally with changes of the time derivative of LV pressure (LVdP/dt) during intravenous infusions of dobutamine and propranolol. Accordingly, the two-electrode conductance catheter was useful in vivo in rabbits for continuously assessing changes in the LV volume.     

Newborn with transverse facial cleft associated with polyhydramnios.

We describe here the case of a female newborn baby with a bilateral complete transverse facial cleft. Obstetrical ultrasound had revealed an increased amount of amniotic fluid from 28 weeks' gestation without fetal hydrops or congenital anomalies. A 1900-g baby girl born at 36 weeks' gestation presented with bilateral wide facial clefts with macrostomia, microphthalmia, nose, and auricular deformities. Her breathing was dependent on life support, which was discontinued 2 hours after birth. An autopsy revealed no congenital malformations in vital organs but the absence of the olfactory nerves. Polyhydramnios and respiratory arrest after birth were presumed to be due to central disintegration of swallowing and breathing, in this case with brain anomaly.     

Bone cells from spinal hyperostotic mouse (twy/twy) maintain elevated levels of collagen productionin vitro

The twy (tiptoe-walking-Yoshimura) mouse is a mutant having a systemic hyperostotic disposition. Osseous overgrowth occurs not only in the spine but also in other skeletal tissues including the calvarium. To clarify the pathogenic mechanism of hyperostotic lesions, bone cells were cultured from twy and normal mouse calvariae to analyze the growth and extracellular matrix production in both genotypes. The cultures of osteoblast-enriched cells were established by explant procedure. The cells of the twy genotype showed accelerated growth and elevated levels of collagen synthetic activity compared to normal cells. However, no significant difference was noted in noncollagenous protein synthesis between the two genotypes. Furthermore, the mutant cells maintained these abnormal functions during several cell passagesin vitro. These results indicated that an unusual phenotype of twy bone cells distinguished by accelerated growth and selective stimulation of collagen production may play a major role in the development of hyperostotic lesions in twy micein vivo.     

Effects of morphine on visceral nociception evoked by colorectal distension in rats: comparative examinations of electrophysiological and behavioral responses

The purpose of this study was to compare the effects of intravenously administered morphine on electrophysiological and behavioral responses to colorectal distension (CRD) and to examine the influence of noxious stimuli applied to another part of the body (a laminectomy) on the visceromotor response to CRD. The effects of morphine (0.1–6.4 mg·kg⁻¹) were examined in rate anesthetized with pentobarbital. Electrophysiological (n=16) and behavioral experiments (n=47) were done. Electrophysiological experiments were conducted to examine the effects of morphine on the responses of visceral dorsal horn neurons to CRD; behavioral studies were conducted to compare the effects of morphine with and without a laminectomy (intact group:n=24; laminectomy group:n=23). Morphine suppressed the evoked activities of the visceral dorsal horn neurons in a dose-dependent manner. Similar suppression of the behavioral visceromotor response was observed. Visceromotor thresholds were significantly lower in the intact group than in the laminectomy group during the control study. When morphine was administered, the visceromotor thresholds in both groups increased to a similar level. Behavioral and neurophysiological responses to CRD were suppressed in a similar fashion by morphine. Although laminectomy affected the threshold values of CRD for visceromotor responses, the laminectomy per se plays an insignificant role when adequate morphine is administered. This abstract was presented at the 7th World Congress on Pain     

Combination Therapy With Recombinant Human Granulocyte Colony-Stimulating Factor and Erythropoietin in Aplastic Anemia

Recombinant human granulocyte colony-stimulating factor (rhG-CSF) and erythropoietin (rhEPO) were used to treat patients with aplastic anemia (AA). In terms of effects on erythrocyte recovery, the combined use of rhG-CSF and rhEPO showed a favorable response in 6 of 14 (42.9%) patients with moderate AA following 10 weeks treatment and in 3 of 14 (21.4%) patients thereafter. However, the response was poor in patients with severe AA (3/13). A favorable response in severe AA was observed in 1 of 13 (7.7%) patients following 10 weeks treatment and in 2 of 13 (15.4%) patients thereafter. The overall effect on erythrocytes was observed in 44.4% patients. A dose of 400 μ/m² G-CSF was sufficient to cause an increase in neutrophil count and 100 IU/kg rhEPO appeared to be sufficient to cause an increase in erythrocyte count. In 6 of 27 (22.2%) patients, a trilineage response was observed. Interestingly, a delayed and long-lasting effect was obtained in 5 of 27 (18.5%) patients. These results suggest that rhG-CSF can synergize with rhEPO in erythrocyte response, especially in patients with moderate AA.     

Morphology and distribution of microtubules in the presecretory and secretory ameloblasts of the rat incisor

The morphology and distribution of microtubules in the ameloblast of the rat incisor were examined. Two types of microtubules distribution were observed: isolated single tubules and multiple tubules. The latter formed bundles of tubules and filaments or sheets of filaments. The thickness of the filament or sheet was almost the same as that of the wall of the microtubule. The filament or sheet as well as the microtubule were negatively stained when treated with tannic acid. The microtubules of the single type were small in number at the undifferentiated stage of the cell. They increased in number in the distal portion of the cell during differentiation, and their number reached a peak in the proximal portion of Tomes' process at the secretory stage of the cell. On the other hand, the multiple microtubules showed a different distribution in the secretory stage of the cell, i.e., they were mostly distributed between the Golgi region and the distal terminal web.     

A novel method for development of malaria vaccines using full-length cDNA libraries

We describe a novel method to screen malaria DNA vaccine candidates using a full-length cDNA library and a murine malaria infection model. For the development of effective malaria vaccines, much effort has been made with meager success. The completion of genome sequencing of Plasmodium falciparum has provided invaluable information for achieving this goal. We have been studying full-length cDNA libraries of malaria parasites as a part of genome analysis. Mice vaccinated with a DNA vaccine consisting of 2000 pooled clones showed significantly prolonged survival after challenge infection. In addition, spleen cells of vaccinated mice produced augmented levels of IL-2 and IFN-gamma when incubated with the crude parasite antigens, indicating that cellular immunity plays an important role in the protection. This approach will not only form the basis for development of malaria vaccines but will also be applicable to other parasites and pathogenic microorganisms.