Preservation of the vasodilative effect of endothelium-derived relaxing factor in the hind limb of the rat

Using an extracorporeal circulatory system of fresh blood, the vasodilative effect of endothelium-derived relaxing factor (EDRF) secreted from vascular endothelium, stimulated by acetylcholine (ACh), was evaluated. The bioassay cascade technique was applied to elucidate the release of EDRF. Elevated blood pressure of freshly amputated rat hind limbs, created by injection of norepinephrine (NE), decreased by 56% with ACh infusion, suggesting the existence of EDRF in the peripheral vascular system of rat hind limbs. The vasodilative effect of EDRF could be preserved for at least 6 hours when stored at room temperature. The effect of EDRF decreased markedly following storage for more than 9 hours at room temperature and storage for more than 3 hours at 4 degrees C.

Methamphetamine antagonistic property of (+)- and (-)-4-phenyltetrahydroisoquinoline in rat anococcygeus muscle

The antagonistic effects of (+)- and (-)-4-phenyl-1,2,3,4-tetrahydroisoquinoline (4PTIQ) on methamphetamine in the rat anococcygeus muscle were compared with those of cocaine and nomifensine. Methamphetamine contracted the anococcygeus muscle through the release of norepinephrine from noradrenergic nerve terminals. (+)-4PTIQ inhibited the methamphetamine-induced contractions more strongly than cocaine and nomifensine. (+)-4PTIQ had no potentiating effects on exogenous norepinephrine-induced contraction, which was considered to be an index of amine neuronal uptake blockade. On the other hand, (-)-4PTIQ, cocaine and nomifensine produced a significant leftward shift of the norepinephrine concentration-response curve, i.e. they showed a strong blocking effect on amine neuronal uptake. These results suggest that the inhibitory effects of (+)-4PTIQ on the action of methamphetamine are mediated by a mechanism other than inhibition of amine neuronal uptake.

[Effects of nisoldipine in heminephrectomized spontaneously hypertensive rats--measurement of afferent and efferent arterioles by microvascular cast]

In this study, we measured cross sectional areas of glomerular arterioles and glomerular volume in heminephrectomized spontaneously hypertensive rats (SHR) treated with a calcium antagonist, nisoldipine (NSL). We also examined the relevance of these parameters to the progression of hypertensive renal injury. Male 6-week-old SHR (n = 14) were heminephrectomized and divided into 2 groups. They were fed regular chow (control, n = 7) or chow containing 0.1% NSL (n = 7). After 12 weeks, urinary protein excretion (UpV) and systolic blood pressure (SBP) were measured. The control rats developed marked hypertension reaching 228 +/- 2 mmHg, and NSL lowered this by 27 mmHg (p < 0.001). NSL reduced UpV by 22% (p < 0.05). Microvascular cast of the kidney was prepared, and the cross sectional areas of the afferent and efferent arterioles as well as glomerular volume were measured using scanning electron microscopy. In the juxtamedullary and subcapsular glomeruli with minor abnormalities, the afferent arteriole was narrower and the glomerular volume was smaller in the NSL-treated rats than in the control rats. These results suggest that the calcium antagonist, NSL, offers the advantage of protecting kidney from hypertensive injury by reducing afferent arteriolar diameter, glomerular hypertrophy and intraglomerular pressure in heminephrectomized SHR.

Egocenter location in children with strabismus: in the median plane and unchanged by surgery

PURPOSE

Previous studies have shown that there are spatial localization shifts after horizontal strabismus surgery when a patient performs an open-loop pointing task. After monocular enucleation, an adult will also show a shift in the pointing response. Other studies have shown that in children who underwent enucleation, the egocenter location shifts toward the remaining eye. Is the pointing shift after surgery in children with strabismus the result of a shift in egocenter location?

METHODS

Using a modified Roelofs' method for measuring the egocenter, eight children were tested before and after horizontal strabismus surgery to see if there were any shifts in egocenter location. One control group consisted of six children undergoing surgery for correction of vertical strabismus in which the horizontal muscles would be unaltered.

RESULTS

Presurgery measurements of egocenter location in the people with strabismus were the same as those found in the other control group of 12 normal children. Postsurgical measurements of eye position showed horizontal rotations of 14.5 degrees for the horizontal group and 2.4 degrees for the vertical group. Egocenter measurements showed no postoperative shift for either strabismus group.

CONCLUSIONS

Thus, the pointing shift seen in the previous studies is not from a shifting egocenter location but from a change in the registered position of the eye in the orbit.

Major-histocompatibility-complex variation in two species of cichlid fishes from Lake Malawi

Lake Malawi in eastern Africa harbors > 500 endemic species of cichlid fishes, all of which are believed to have emerged from a single founding population in the past 2 Myr. Molecular characterization of differences among the species could provide important information about the nature of speciation in the period of adaptive radiation. Because of the close relationship, however, molecular variation among the species has been difficult to ascertain. In this communication, we provide evidence for extensive differences, in major-histocompatibility-complex (Mhc) class II genes, between two related species, Pseudotropheus zebra and Melanochromis auratus. We used specific primers to amplify and sequence intron 1 and exon 2 of the class II genes from 18 individuals. Although we found 20 different sequences among the 42 that we produced, there was not a single sequence shared by the two species. Thus the study suggests that different cichlid species of Lake Malawi have different profiles of class II alleles, presumably because the polymorphism present in the ancestral founding population segregated differentially into the various species. These results make Mhc genes an important tool for elucidating speciation.

Blood flow through prefabricated flaps--an experimental study in rabbits

Prefabricated flaps were created by femoral vessel implantation beneath the abdominal skin in rabbits. The area of survival and blood flow through the prefabricated flap were measured after 1, 2, 4, 6, 8, and 12-week intervals. The parameters at 6, 8 and 12-week intervals were significantly larger than those for random pattern flaps (p < 0.01), but were significantly smaller than those for axial pattern flaps (p < 0.01). The minimum interval at which the prefabricated flap could be transferred successfully was between 6 and 8 weeks in this model. Microangiography demonstrated that neovascularisation began at the distal end of the implanted vascular bundle and spread throughout the flap by 8 weeks.

[A case of recurrent mediastinal goiter (oxyphilic cell carcinoma)]

A case of recurrent mediastinal goiter (oxyphilic cell carcinoma) in a 66-year-old female was reported. 19 years ago, the patient submitted to a right-hemithyroidectomy for the oxyphilic cell adenoma. Since two months, her dyspnea gradually aggravated. On admission, abnormal mass of right upper mediastinum was shown by chest X-ray. CT scan and MRI showed a 8 cm sized right upper mediastinal tumor with tracheal compression.

4-Phenyltetrahydroisoquinoline, but not nomifensine or cocaine, inhibits methamphetamine-induced dopamine release

The inhibitory effect of 4-phenyltetrahydroisoquinoline (4-PTIQ) on methamphetamine-induced dopamine release in the rat nucleus accumbens was investigated using a brain microdialysis method. Methamphetamine (10(-6) M) infusion through a microdialysis probe induced the release of dopamine. Although the uptake inhibitors, cocaine (3 x 10(-6) M) and nomifensine (10(-6) M), failed to block dopamine release, 4-PTIQ (10(-6 M) inhibited the dopamine-releasing effect of methamphetamine. 4-PTIQ did not affect the elevation of the extracellular dopamine level induced by high concentrations of nomifensine (10(-5) M) and cocaine (3 x 10(-5) M). 4-PTIQ was the weakest inhibitor of [3H]dopamine uptake by rat striatal synaptosomes. These results suggest that 4-PTIQ is a selective antagonist against the dopamine-releasing effect of methamphetamine in the nucleus accumbens.

Chemoembolotherapy for recurrent hepatocellular carcinoma in the residual liver after hepatectomy

The efficacy of transcatheter arterial chemoembolization using Lipiodol (TACE) to treat recurrent hepatocellular carcinoma (r-HCC) in the residual liver after radical hepatic resection was evaluated. During the last 8 years, TACE was performed in 68 patients with r-HCC for an aggregate total of 150 times. Of the 68 patients, 4 had a massive type r-HCC with tumor thrombus in the main portal vein (PVTT) at the time of the first TACE. Among the remaining 64 patients without PVTT, multiple r-HCCs were revealed in 46, and a single r-HCC in 18 by angiography and/or follow-up CT scans after the initial TACE. In 26 of the 68 patients (38.2%), at least one or more r-HCCs were fed not only by the hepatic arteries, but also by the extrahepatic collateral arteries, such as branches of the right inferior phrenic artery. The cumulative survival rates of these patients after hepatectomy and after the initial TACE for r-HCC were 98.6% and 87.1% for one year, 89.7% and 62.9% for 2 years, 74.0% and 34.3% for 3 years, 53.1% and 20.0% for 4 years and 40.3% and 0% for 5 years (mean survival duration: 1,647 days and 947 days), respectively. These results indicate that repeat TACE against r-HCC can help obtain long-term survival in patients with r-HCC. However, during TACE, we must give consideration to the newly developed collateral feeding artery to the r-HCC.

Effect of the centrally acting muscle relaxant tizanidine on spinal reflexes: involvement of descending noradrenergic systems

Experiments were performed on intact and spinalized rats anesthetized with urethane and alpha-chloralose. In intact rats, administration of tizanidine (0.1 mg/kg, i.v.) decreased the mono- (MSR) and polysynaptic reflex potentials (PSR). Blood pressure was initially elevated and then lowered by tizanidine. Although pretreatments with hexamethonium and phentolamine prevented the tizanidine-induced decrease in blood pressure, the depressant effects of tizanidine on the reflexes remained. The alpha 2-antagonist idazoxan inhibited the tizanidine-induced decrease in spinal reflexes, suggesting that central alpha 2-adrenoceptors are involved in the depression of the reflexes. In spinalized rats, tizanidine transiently increased the MSR and gradually decreased the PSR. Blood pressure was elevated transiently by tizanidine. Although the hypertensive effect of tizanidine was inhibited by phentolamine, the effect of tizanidine on the PSR did not change. Prazosin blocked the stimulatory effect of tizanidine on the MSR and caused a rapid decrease of the PSR, suggesting that spinal alpha 1-adrenoceptors are involved in the enhancement of the reflexes. These results suggest that the depressant effects of tizanidine on spinal reflexes are due to the supraspinal and spinal effects of the drug, and not to changes in blood pressure.

Inhibitory effect of 4-phenyltetrahydroisoquinoline on locomotion and dopamine release induced by micro-injection of methamphetamine into the nucleus accumbens of the rat

The inhibitory effects of 4-phenyl-1,2,3,4-tetrahydroisoquinoline (4-PTIQ) on methamphetamine-induced increases in dopamine and locomotion were investigated. Methamphetamine hydrochloride (10 micrograms) microinjected into the nucleus accumbens increased both locomotor activity and extracellular dopamine levels, measured by the brain microdialysis method. 4-PTIQ hydrochloride (20 micrograms) co-injected with methamphetamine inhibited both the increase in dopamine and the locomotor activity. The uptake blocker cocaine hydrochloride (20 micrograms) co-injected with methamphetamine failed to inhibit the effect of methamphetamine. Thus 4-PTIQ but not cocaine inhibited the dopamine-releasing effect of methamphetamine, and 4-PTIQ is suggested to block methamphetamine-induced locomotion by inhibition of dopamine release.

Depression of the monosynaptic reflex by apomorphine or bromocriptine is not mediated by D1/D2 receptors

The role of dopamine in spinal motor transmission was investigated using spinal reflexes in acutely spinalized rats. Intravenous administration of a relatively high dose of the dopamine receptor agonist apomorphine-HCl (3 mg/kg) or the D2 receptor agonist bromocriptine mesylate (1 mg/kg) reduced the amplitude of the monosynaptic reflex (MSR). Depression of the MSR by both drugs was antagonized by haloperidol (1 mg/kg), but not by the D2 receptor antagonists YM-09151-2 (0.2 mg/kg) and sulpiride (10 mg/kg), or by a combination of the D1 receptor antagonist SKF 83566 (0.01 mg/kg) and sulpiride (10 mg/kg). Intravenous administration of the selective D1 receptor agonist SKF 77434 (0.1 and 1 mg/kg) and the D2/D3 receptor agonist quinpirole-HCl (0.1 and 1 mg/kg) had no significant effect on the MSR. Simultaneous administration of SKF 77434 and quinpirole had no significant effect on the MSR. These results show that stimulation of D1/D2 receptors has little influence on the MSR, and suggest that descending dopaminergic systems mediating these receptors have little influence on MSR transmission. Apomorphine and bromocriptine may inhibit the MSR via other subtypes of D1/D2 or other, as yet undiscovered, dopamine receptors or via non-dopaminergic mechanisms.

[Effect of arotinolol on the incomplete tetanic contractions of the cat soleus muscle--relation to its anti-tremorgenic action]

The effect of arotinolol on the incomplete tetanic contractions of the cat soleus muscle was studied. Isoproterenol and epinephrine injected intravenously decreased the tension and degree of fusion of incomplete tetanic contractions of the soleus muscle in anesthetized cats. Intravenous arotinolol (> 3 micrograms/kg), propranolol (> 30 micrograms/kg) and pindolol (> 3 micrograms/kg) blocked the effects of isoproterenol and epinephrine, but atenolol (-300 micrograms/kg), prazosin (0.1-10 micrograms/kg) and phentolamine (10, 30 micrograms/kg) did not block them. These results indicate that the receptors involved can be classified as of the beta 2-type. It is proposed that arotinolol may inhibit beta 2-adrenoceptors in the extrafusal muscle fibers of slow muscle, and thereby reduces the amplitude of tremor by changing the incomplete tetanic contractions of the muscle to the complete ones.

Automatic suspension device for gait training

The automatic suspension device (REHABOT) suspends the patient's body in a standing position allowing the patient to walk around the circular handrail without forward propulsion. Reduction of body weight is accurately maintained automatically while safely supporting the patient. The device was used for 23 patients with orthopaedic disorders or central nervous system disorders who were chosen because of their initial difficulties with gait training in parallel bars. Its advantages are that (1) it may be used for patients with open wounds or cardiac problems, or patients using prostheses or orthoses, (2) preparation and walking practice are simpler both for patients and staff than the therapeutic pool and walking trolley, (3) running costs are lower than the therapeutic pool. Its drawbacks are that the initial cost is relatively high, only one patient can be trained at a time, and the effect of warm water is missing. The automatic suspension device will become one of the new and fundamental pieces of equipment for gait training, especially for hospitals where there are many elderly patients and also severely and multiple disabled persons.

Malignant osteopetrosis treated with high doses of 1 alpha-hydroxyvitamin D3 and interferon gamma

A male infant with malignant osteopetrosis was treated with high doses of 1 alpha-hydroxyvitamin D3 and interferon gamma. Therapy with 1 alpha-hydroxyvitamin D3 increased the serum calcium level despite the markedly elevated serum level of 1 alpha, 25-dihydroxyvitamin D before treatment. Recombinant human interferon gamma increased neither the bone mineral nor matrix turnover, and was not tolerated because of bone marrow suppression.

Revascularization procedures in the treatment of Kienböck's disease

Lunate revascularization by means of vascular bundle implantation is one of the useful procedures for stages I and II Kienböck's disease, but for stage III, it should be combined with some biomechanical procedure or partial carpal fusion. There is no indication for this procedure in stage IV disease.

Extensive MHC variability in cichlid fishes of Lake Malawi

Lake Malawi in East Africa harbours 500-1,000 endemic species of cichlid fishes, all presumably derived by adaptive radiation from a single founding population within the past two million years. The species of this 'flock' differ strikingly in their ecology and behaviour, moderately in their external morphology and very little in their molecular characteristics. Here we describe high sequence variability of class II major histocompatibility complex genes in a sample of species from Lake Malawi. The variability provides a set of molecular markers for studying adaptive radiation and should be useful for estimating the size of the population that founded the species flock.

[Prediction of performance status after pneumonectomy]

To predict performance status (P.S.) following pneumonectomy, patients with lung carcinoma underwent pre-surgical pulmonary function tests with spirometry and unilateral pulmonary artery occlusion test (UPAO test). Between 1980 and 1991, twenty-nine patients who had survived more than six months after surgery were selected for the study. These patients were divided into two groups according to P.S. measured at six months after surgery: 16 patients with P.S. 0 to 1 were in Group A, and 13 patients with P.S. 2 to 3 were in Group B. The results of the following tests obtained prior to surgery were compared for the two groups to predict post-surgical P.S.; vital capacity (VC), VC/m2, forced expiratory volume in 1 second (FEV1.0), FEV1.0/m2, predicted VC/m2 and predicted FEV1.0/m2 calculated with residual pulmonary segments, mean pulmonary arterial pressure (PPA) before UPAO and 15 minutes after UPAO, total pulmonary vascular resistance (TPVR) before and during UPAO, and rate of changes in PPA and TPVR. Results obtained were as follows: Group B demonstrated significantly higher TPVR (p < 0.05) before the UPAO, PPA (p < 0.05) and TPVR (p < 0.002) during UPAO, and rate of change in TPVR (p < 0.02) than those in Group A. There were no significant differences between the two groups for other test results. From these results, lowering of post-surgical P.S. might be predicted when the TPVR during UPAO was 350 dyne.sec.cm-5/m2 or more.

Rapid diagnosis of gastric malignant lymphoma from biopsy specimens: detection of immunoglobulin heavy chain rearrangement by polymerase chain reaction

The endoscopic appearances of the gastrointestinal lymphomas differ widely, and it is often difficult to make the distinction between a benign lymphoproliferative disorder and a malignant lymphoma even with a histologic evaluation. Since almost all primary malignant lymphomas of the gastrointestinal tract are of B-cell origin, the confirmation of monoclonality in immunoglobulin (Ig) is helpful for differential diagnosis. Rearrangements of the Ig heavy chain gene were examined by polymerase chain reaction (PCR) analysis in frozen biopsy specimens of human stomach. The sensitivity of the analysis was sufficient to detect even a 5% clonal B-cell proliferation and results could be obtained within 17 h. In a clinical investigation, seven of eight cases (88%) of primary gastric malignant lymphoma showed a single band in polyacrylamide gel electrophoresis (PAGE) after PCR, suggesting a monoclonal proliferation of B-cell lineage. By contrast, all seven cases of reactive lymphoreticular hyperplasias showed a broad smear pattern in PAGE, which is thought to reflect polyclonal proliferation. None of the lymphocytes infiltrating around gastritis (7 cases), gastric ulcers (12 cases) and gastric carcinomas (15 cases) showed a monoclonal proliferation pattern. These findings suggest that detection of monoclonality in Ig heavy gene rearrangement by PCR is useful for the differential diagnosis of B-cell lymphoproliferative diseases in the gastrointestinal tract.

Exon-intron organization of fish major histocompatibility complex class II B genes

Major histocompatibility complex (Mhc) molecules bind self and foreign peptides and present them to lymphocytes for recognition. Activation of lymphocytes by Mhc-bound foreign peptides leads to specific immune response against parasites. The Mhc genes have been studied extensively in mammals and birds but much less in other vertebrate classes. In this communication we provide the first description of the exon-intron organization of class II beta-chain-encoding genes from the teleost fish Aulonocara hansbaenschi, family Cichlidae. Each of the genes consists of six exons, E1 through E6, encoding the leader peptide (E1), beta 1 domain (E1+E2), beta 2 domain (E3+E4), connecting peptide (E5), transmembrane region (E5), cytoplasmic domain (E5+E6), and the 3' untranslated region (E6). The exons are separated by relatively short introns, the length of the longest intron being 1.3 kilobase pairs. An important difference between these and all other known class II B genes is that the beta 2 domain-encoding exon is split by an intron 97 base pairs in length. The intron is absent in other teleost fishes such as Brachydanio rerio. A change in the 3' splice site of intron 4 in some of the genes of A. hansbaenschi and of another cichlid fish, Cyphotilapia frontosa, has produced two extra codons at the 5' end of exon 5. Comparison of the A. hansbaenschi coding sequences with those of C. frontosa has revealed a concentration of variability in exon 2 and part of exon 3. Taken together, these observations provide evidence for the existence in cichlid fishes of at least two class II B loci which are functionally equivalent to the corresponding loci in mammals. The exon-intron organization and sequence similarities indicate that the two loci arose by duplication from a common ancestral gene.