Use of epr oximetry with india ink to measure the po2 in the liver in vivo in mice

The partial pressure of oxygen (pO₂) of the liver in vivo in unanesthetized mice was determined using electron paramagnetic resonance (EPR) oximetry with India ink. The EPR spectra were obtained using a low-frequency (1.2 GHz) EPR spectrometer with a loop gap cavity resonator. The line width of the India ink used in this experiment was reversibly broadened by oxygen and was particularly sensitive to pO₂ below 30 torr. After the administration of India ink into the tail vein, the India ink particles were taken up mainly by Kupffer cells in the liver and in part by phagocytes in the spleen. The pO₂ measured in the normal liver was about 14 torr and was constant for the 2-week experimental period. The pO₂ decreased when measured at 1, 2, and 6 days after treatment with a hepatotoxin (carbon tetrachloride (CCI₄)); within 2 weeks, it returned almost to the initial level. Measurements by EPR at sacrifice of controls and CCI₄-treated mice indicated that more than 90% of the India ink went to the liver; the spleen contained 4.7% of total amount in control mice and 8.8% in CCI₄-treated mice when measured 2 weeks after the treatment. These data indicate the usefulness of India ink for measuring the pO₂ of the liver in vivo and that the pO₂ in the Kupffer cells is decreased when the liver is damaged by CCI₄.     

Involvement of NMDA and NonNMDA Receptors in Motor Task--related Activity in the Primary and Secondary Cortical Motor Areas of the Monkey

The involvement of the NMDA and non-NMDA receptors in the task-relatedneuronal activity of the primary motor cortex (MI), premotorcortex (PM), supplementary motor area (SMA), and an area rostralto the SMA (pre-SMA) of two monkeys (Macace fuscata) was examinedduring performance of a trained motor task. The selective NMDAantagonist 0-2-amino-5-phosphonovaleric acid (APV) and the non-NMDAantagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) wereiontophoretically applied to motor task-related neurons. A totalof 568 task-related neurons (435 movement related, 83 set related,50 mixed type) were recorded from the MI, PM, SMA, and pre-SMA,and the effects of APV and CNQX were examined in the individualneurons. In many neurons, APV selectively or preferentiallysuppressed the spontaneous discharge rather than movement-relatedactivity. In many neurons, the movement-related activity wasmore selectively or effectively suppressed by CNQX than by APV.However, the set-related activity was affected by both APV endCNQX. The neurons in layers I and II were affected more stronglyby APV end CNQX than those in layers V and VI. No correlationwas found between the magnitude of task-related activity inthe control (no drug application) period and the effectivenessof APV or CNOX. These results indicate that both NMDA and non-NMDAglutamate receptors are involved in motor task-related neuronalactivity of both primary and secondary motor areas, althoughthe contribution of these two receptors to individual neuronalactivity varies a great deal.     

Macrophage Accumulation, Division, Maturation and Digestive and Microbicidal Capacities in Tuberculous Lesions: I. Studies Involving their Incorporation of Tritiated Thymidine and their Content of Lysosomal Enzymes and Bacilli

Dermal and pulmonary tuberculous lesions were produced in rabbits with BCG, biopsied, incubated in vitro with tritiated thymidine (³HT) under hyperbaric oxygen, quickly frozen, sectioned in a cryostat, stained for the lysosomal enzyme β-galactosidase, autoradiographed, stained for acid-fast bacilli and counterstained with hematoxylin. As macrophages developed into epithelioid cells, they could still divide—ie, incorporate ³HT. However, once they became fully mature epithelioid cells that were 4-plus in β-galactosidase, they could not do so. Tuberclebacilli did not stimulate macrophage division. On the contrary, macrophages containing bacilli did not divide, except when the lesions began. During the development of tuberculous lesions, macrophages (including those rich in enzymes and those containing bacilli) died, forming caseous centers. Therefore, local cell division did not seem to be the main mechanism by which macrophages reduced their bacillary load. Such division seemed mainly to occur in young macrophages that had recently immigrated into the lesions from the bloodstream and had not yet ingested bacilli.     

Vascular Endothelial Growth Factor/Vascular Permeability Factor Is Temporally and Spatially Correlated with Ocular Angiogenesis in a Primate Model

Ischemia often precedes neovascularization. Inocular neovascularization, such as occurs in diabetic retinopathy, a diffusible angiogenic factor has been postulated to be produced by ischemicretina and to lead to neovascularization of theretina, optic nerve, or iris. However, no angiogenic factor has been conclusively identified that satisfies this hypothesis. Vascular endothelial growth factor/vascular permeability factor, hereafter referred to as VEGF, is a likely candidate for an ocular angiogenic factor because it is a secreted mitogen, specific for endothelial cells, and is upregulated by hypoxia. We investigated the association of VEGF with the development of experimental iris neovascularization in the cynomolgus monkey. Following theproduction of retinal ischemia by laser occlusion of all branch retinal veins, VEGF was increased in the aqueous fluid, and the aqueous VEGF levels changed synchronously and proportionally with the severity of iris neovascularization. Northern analysis and in situ hybridization revealed that VEGF messenger RNA is upregulated in the ischemic retina. These observations support the hypothesis that ocular neovascularization is regulated by a diffusible factor and identify VEGF as a likely candidate for a retina-derived vascular permeability and angiogenesis factor in vivo.     

Cross education of muscular strength during unilateral resistance training and detraining

Abstract. The purpose of the present study was to examine the changes in maximum voluntary isometric contraction (MVC) in the contralateral untrained limb during unilateral resistance training and detraining, and to examine the factors inducing these changes by means of electrophysiological techniques. Nine healthy males trained their plantar flexor muscles unilaterally 4 days·week^–1 for 6 weeks using 3 sets of 10–12 repetitions at 70–75% of one-repetition maximum a day, and detrained for 6 weeks. Progressive unilateral resistance training significantly (P<0.05) increased MVC, integrated electromyogram (iEMG), and voluntary activation in the trained and contralateral untrained limbs. The changes in MVC after training were significantly correlated with the changes in iEMG in both limbs. No significant changes occurred in MVC, voluntary activation, and iEMG in the contralateral limb after detraining. The changes in MVC after detraining did not correlate with the changes in voluntary activation or iEMG in either limb. Training and detraining did not alter twitch and tetanic peak torques in either limb. These results suggest that the mechanisms underlying cross education of muscular strength may be explained by central neural factors during training, but not solely so during detraining. Electronic Publication     

A medaka gene map: the trace of ancestral vertebrate proto-chromosomes revealed by comparative gene mapping

The mapping of Hox clusters and many duplicated genes in zebrafish indicated an extra whole-genome duplication in ray-fined fish. However, to reconstruct the preduplication chromosomes (proto-chromosomes), the comparative genomic studies of more distantly related teleosts are essential. Medaka and zebrafish are ideal for this purpose, because their lineages separated from their last common ancestor approximately 140 million years ago. To reconstruct ancient vertebrate chromosomes, including the chromosomes of the vertebrate ancestor of humans from 450 million years ago, we mapped 818 genes and expressed sequence tags (ESTs) on a single meiotic backcross panel obtained from inbred strains of the medaka, Oryzias latipes. Comparisons of linkage relationships of orthologous genes among three species of vertebrates (medaka, zebrafish, and human) indicate the number and content of the chromosomes of the last common ancestor of ray-fined fish and lobe-fined fish (including humans), and the extra whole genome duplication event in the ray-fin lineage occurred in the common ancestor of perhaps all teleosts.     

Mutation analysis of two Japanese patients with Fanconi-Bickel syndrome

Fanconi-Bickel syndrome (FBS), or glycogen storage disease type XI, is a rare autosomal recessive disorder characterized by hepatorenal glycogen accumulation, Fanconi nephropathy, and impaired utilization of glucose and galactose. Recently, this disease was elucidated to link mutations in the glucose transporter 2 (GLUT2) gene. Only three mutations in three FBS families have been reported. Therefore, it is important to elucidate mutations in the GLUT2 gene in FBS by answering the question of whether the syndrome is a single gene disease. In this report, we describe two patients in two unrelated families clinically diagnosed with FBS. No mutation in the entire protein coding region of the GLUT2 gene was detected in patient 1, which suggested that no mutation existed in the GLUT 2 gene, or that some mutations had affected the expression of the GLUT 2 gene. In patient 2, a novel homozygous nonsense mutation (W420X, Trp at codon 420 to stop codon) was detected. These results support the correlation between GLTU2 gene mutation and FBS syndrome. However, many patients must be analyzed to determine whether other genes are involved in FBS. Received: July 16, 1999 / Accepted: September 3, 1999     

Two movement-related foci in the primate cingulate cortex observed in signal-triggered and self-paced forelimb movements

1. Single-unit activity in the cingulate cortex of the monkey was recorded during the performance of sensorially (visual, auditory, or tactile) triggered or self-paced forelimb key press movements. 2. Microelectrodes were inserted into the broad rostrocaudal expanse of the cingulate cortex, including the upper and lower banks of the cingulate sulcus and the hemispheric medial wall of the cingulate gyrus. 3. A total of 1,042 task-related neurons were examined, the majority of which were related to the execution of the key press movements. In greater than 60% of them, the movement-related activity preceded the activity in the distal flexor muscles. 4. The movement-related neurons were distributed, in two foci, in the posterior and anterior parts of the cingulate cortex, both including the upper and lower banks of the cingulate sulcus. The posterior focus was found to largely overlap the area projecting to the forelimb area of the primary motor cortex by the use of the horseradish peroxidase (HRP) method. 5. About 40% of the cingulate cortical neurons showed equimagnitude responses during the signal-triggered and self-paced movements. The neurons exhibiting a selective or differential response to the self-paced motor task were more frequently observed in the anterior than in the posterior cingulate cortex. 6. The long-lead type of changes in activity, ranging from 500 ms to 2 s, were observed mainly before the self-paced and, much less frequently, before the triggered movements. They were particularly abundant in the anterior cingulate cortex. 7. Only a few of the neurons showed activity time-locked to the onset of the sensory signals. 8. These observations indicate that the anterior and posterior parts of the cingulate cortex are distinct entities participating in the performance of limb movements, even if the movements are simple, such as those in this study.