Spinal lamina I neurons projecting to the parabrachial area of the cat midbrain

We have observed a population of lamina I neurons in the cat that has projections to the parabrachial area (parabrachial and cuneiform nuclei). A subpopulation of these neurons also projects to the contralateral thalamus. The majority of projecting cells responded exclusively to noxious stimuli, a few wide-dynamic-range neurons were also observed. Conduction velocities for antidromic activation from the midbrain ranged from 1 to 18 m/s. We stained 14 cells intracellularly with horseradish peroxidase. These findings suggest that a major nociceptive projection pathway originating in lamina I and terminating in the parabrachial area exists in the cat.     

Endothelial Lined Skeletal Muscle Ventricles: Open and Percutaneous Seeding Techniques

Twelve bilateral skeletal muscle ventricles (SMVs) were constructed in six dogs by wrapping each latissimus dorsi muscle around a cylindrical, plastic mandrel (volume 30 cc). After 6 to 10 weeks, five dogs had one of their SMVs seeded with allogeneic cultured canine endothelial cells (8 times 10⁶ cells/pouch) via an open technique, while the contralateral SMV was seeded by percutaneous injection of cells into the space around the mandrel. After 1 week, the SMVs were excised. Viable, adherent endothelial cells were present in all seeded pouches; this was confirmed via fluorescent microscopy with several endothelial cell markers: KLH-2, dilacetylated low-density lipoprotein and antibodies to von Willebrand factor. The inner lining of the SMVs were also examined with scanning and transmission electron microscopy; the highest concentration of cells were seen at the apex where a continuous endothelial monolayer was observed. No significant difference in the distribution or the morphology of the endothelial lining was noted between the open and percutaneous seeding techniques. These data show that SMVs can be seeded with an endothelial monolayer using both open and percutaneous techniques.     

Effects of fasting on distribution and excretion of lead following long-term lead exposure in rats

Lead was given to rats through drinking water containing 100 ppm lead acetate for 20 days. Delta-aminolevulinic acid dehydratase (ALAD) activity in erythrocytes was significantly lower (p < 0.05) at 20 days after Pb treatment. Erythrocytic ALAD activity was significantly lower (p < 0.05) in fasted rats than in fed rats with or without Pb pretreatment. Serum glutamic pyruvic transaminase and glutamic oxaloacetic transaminase activities after 6 days of fasting were significantly higher (p < 0.05) in Pb pretreated rats than in other groups (Ph nontreated fed and fasted rats, and Pb pretreated fed rats). Long periods of fasting strongly enhanced these serum-enzymes elevations induced by lead. Maximum Pb concentrations and total amount in feces increased in rats fasted for 3 days regardless of Pb pretreatment. On the other hand, total amount of Pb in feces of rats fasted for 6 days were not significantly different from the other groups because their fecal volume decreased to about 1 % of fed rats. The Pb concentrations of liver, kidney, spleen, and femur increased significantly in Pb pretreated rats compared to in controls, but there were no significant differences between the fed and fasted rats.     

Slow fluctuations of single unit activities of hippocampal and thalamic neurons in cats. II. Role of serotonin on the stability of neuronal activities

A series of experiments was carried out both in the hippocampal pyramidal and thalamic ventrobasal neurons to investigate the effect of serotonin level in the brain on slow fluctuations of neuronal discharges. Single neuronal activities were recorded in the following two pharmacologically treated states: (1) a 5-hydroxytryptamine depleted state by p-chlorophenylalanine administration (PCPA phase) and (2) a 5-methoxy-N,N-dimethyltryptamine administered state under the PCPA pretreatment (5-MeODMT phase). The slow fluctuations of neuronal activities in the frequency range of 0.02-1.0 Hz in both nuclei were prominent during the PCPA phase and were similar to those during the paradoxical sleep. In contrast, slow fluctuations were suppressed during the 5-MeODMT phase and neuronal activities during this phase were similar to those during slow wave sleep (SWS). The results show that serotonin in the brain definitely plays a role in stabilizing single neuronal activities.     

Successful surgery for an acute type A aortic dissection following repair of a descending thoracic aortic aneurysm

Acute type A aortic dissection in the presence of a previously repaired atherosclerotic descending thoracic aortic aneurysm is rarely reported. We experienced a patient who underwent an ascending aortic replacement with reconstruction of the aortic arch 16 months after repair of a descending thoracic aortic aneurysm. We succeeded in the redo operation with comprehensive techniques involving selective cerebral perfusion, deep hypothermia, early antegrade systemic circulation for cerebral protection, and femoro-femoral bypass with occlusion of the descending aorta for lower systemic perfusion as well as renal perfusion. The patient recovered and is doing well one year after the redo operation.     

Effects of extrinsic horizontal cell polarization on spike discharges in the carp retina

The effects of horizontal cell polarization on spike discharges were explored in superfused preparations of the carp retina. Light-induced discharge patterns of individual units were determined with spot and annulus stimuli of white light. The effects observed were classified in three response modes (common, reversed and transient). They were consistently observed as the tangential distance between the recording and current-injection electrodes was increased up to 400 μm. The common mode of response consisted of off-discharges upon depolarization and on-discharges upon hyperpolarization of horizontal cells. The reversed mode was opposite to the common. The transient mode consisted in transient spike discharges at the on- and off-sets of extrinsic currents injected into horizontal cells. The common mode of response was observed in 3 of 9 ON-center units, all of 20 OFF-center units and in 3 of 21 ON-OFF units. The reversed mode was seen in 6 of 9 ON-center units and in 4 of 21 ON-OFF units. The transient mode was only found in ON-OFF units. ON-center units can be divided into two subgroups: some responded with the common and others with the reversed mode. All OFF-center units showed exclusively the common mode. On the other hand, all 21 ON-OFF units showed the transient mode, but 9 exhibited one or two additional modes of response; 5 of them showed two (common and transient) modes and 4 showed all three modes, depending upon horizontal cells into which polarizing currents were injected.     

Changes of intracranial pressure during the rupture of intracranial aneurysms: Prognosis for survival

The intracranial pressure at the time of rebleeding from an intracranial aneurysm was recorded in 4 patients who were undergoing conservative treatment pending clinical improvement. Two died of severe hemorrhages and the remaining two recovered. In the deceased patients, repeated rapid increases in the intracranial pressure in a short time caused by rupture of the intracranial aneurysm were observed. In the surviving patients, the intracranial pressure increased only once, owing to the rupture of the intracranial aneurysm. We suggest that sudden death following the rupture of an intracranial aneurysm may result from frequent, repeated bleeding causing an intracerebral hematoma or severe brain swelling, or both.     

GENERAL ASPECTS: Sex Education in Japan

The purpose of the present paper is to illustrate sex education in Japan, shedding light on its historical background. Firstly, the ideas of sex education and the social environments from the Edo period up to modern times are mentioned. Secondly, the current sexual activities of young people, based on nation-wide sampling surveys, are discussed. Geographical variation of teenage fertility in Japan is shown as well. Finally, the paper describes the recent activities of the educational profession in sex education and the measures taken by the Administration to cope with the rise in teenage pregnancies.     

Fractionation and characterization of urinary heparan sulfate excreted by patients with Sanfilippo syndrome

Urinary heparan sulfates (HS) from two siblings with mucopolysaccharidosis (MPS) III-B were fractionated by chromatography with Dowex 1 and Sephadex G-50. Their Mr ranged from 1600 to 8000, and 95% of them were included in the region less than 5000. Fractions with lower Mr contained larger amounts of O-and N-sulfates. The chemical analysis and deaminative cleavage of HS suggested that an intact HS molecule was composed of some blocks rich in GlcNAc and GlcUA and other blocks rich in GlcNS, IdUA and O-sulfate. GlcNAc-UA-GlcNS-UA-GlcNAc-UA-GlcNAc was found to be a major oligosaccharide of HS with Mr less than 1800. Trisaccharides, GlcNAc-GlcUA-aMan and GlcNAc-IdUA-aMan, were released from the nonreducing end of HS-oligosaccharides by deaminative cleavage. They carried 0-3 moles of ester sulfate. GlcNAc-IdUA-aMan was more sulfated than the other. The release of significant amounts of nonsulfated trisaccharide conform to the enzyme defect in this disease. Urinary HS obtained from another patient with MPS III were examined by the same way. Although the patient was not examined enzymatically, the structure of urinary GAG suggested a defect of alpha-N-acetylglucosaminidase in the patient.