Does substance P act as a pain transmitter?

Pain signals appear to be transmitted by a variety of chemicals. Masanori Otsuka and Mitsuhiko Yanagisawa review evidence that substance P, present in 10–20% of primary afferent fibers, is one such transmitter. In the isolated CNS preparations of the newborn rat the tachykinin antagonist spantide reversibly depresses nociceptive C-fiber reflexes of slow-time course without affecting the monosynaptic reflex. These observations together with other lines of evidence suggest that SP serves as a transmitter in a subpopulation of primary afferent C-fibers and produces slow excitatory postsynaptic potentials in second-order neurons in the dorsal horn to transmit delayed pain signals to the CNS.     

The enhanced expression of the matrix metalloproteinase 9 in nasal NK/T-cell lymphoma

Background  

Nasal NK/T cell lymphoma is an aggressive disease and has a poor prognosis. Nasal NK/T cell lymphoma is refractory to conventional chemotherapy and has strong tendency of widespread relapse or dissemination into distant sites.     

Localization of mRNA for inflammatory cytokines in radicular cyst tissue by in situ hybridization, and induction of inflammatory cytokines by human gingival fibroblasts in response to radicular cyst contents

The expression of mRNA encoding the inflammatory cytokines interleukin-1α (IL-1α), interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8) and tumor necrosis factor α (TNF-α) have been examined in radicular cysts by in situ hybridization. Furthermore, the biological activity of the contents of radicular cysts (RCC) has been assayed by adding extracts of RCC to cultured human gingival fibroblasts (HGFs) and analyzing the culture medium for the release of inflammatory cytokines. In the epithelial layer, keratinocytes expressed all cytokine mRNAs examined at various levels. Basal layer cells expressed mRNA for each cytokine. In the subepithelial granulation tissue of the cysts, fibroblasts and macrophages expressed mRNA for IL-6, IL-8, IL-1β and TNF-α mRNA at varying levels; especially clear expression of TNF-α and IL-1β mRNA was detected on macrophages. The infiltrating lymphoid cells, largely composed of T cells and plasma cells, expressed these cytokine mRNAs, especially those encoding IL-6 and IL-8, at various levels. In vitro analysis indicated dose-dependent release of both IL-6 and IL-8 by HGFs in response to RCC. After heating to 100°C for 10 min, RCC almost completely failed to stimulate IL-6 release from HGFs. Furthermore, anti-IL-1β antibody (neutralization test) did not prevent the stimulation of IL-6 release by RCC. Significant amounts of IL-6 and IL-8 were detected in RCC in two cases, and a trace amount of IL-1β was detected in one case. This study demonstrated the wide expression of mRNA encoding inflammatory cytokines in radicular cyst tissues, and RCC itself was capable of stimulating 1L-6 and 1L-8 production from HGFs.     

Venous hemangioma of the mesoappendix: Report of a case and a brief review of the Japanese literature

We present herein the rare case of a 48-year-old man in whom an abdominal mass, revealed by celiotomy to be a solid tumor of the mesoappendix, was histologically diagnosed as having a venous hemangioma. To our knowledge, only 18 cases of mesenteric hemangioma have been reported in Japan, including the present case. However, establishing a correct diagnosis preoperatively is extremely difficult despite advanced imaging techniques. In fact, a mesenteric mass was diagnosed preoperatively in only 3 of these 18 cases. Complete excision with or without bowel resection was performed in 16 cases. Interestingly, the histological diagnosis of all the previous cases was cavernous hemangioma, confirming that this report decuments the first case of venous hemangioma of the mesentery in the Japanese literature.     

Extraadrenal pheochromocytoma: dynamic demonstration at 0.5 tesla.

We report a case of extraadrenal pheochromocytoma of Zuckerkandl imaged by dynamic magnetic resonance imaging (dynamic MRI) with a 0.5 tesla (T) machine. The dynamic MRI proved useful in disclosing the tumor clearly because of strong enhancement in its early phase. This case has the advantages of dynamic computed tomography (dynamic CT) as well as of T2-weighted spin-echo (SE) MR images.     

A simple method for screening assessment of acute toxicity of chemicals

We proposed a simple method for screening assessment of acute oral and dermal toxicity using only three rats and mice of each sex at each dose level. Animals were first treated with chemicals at a dose of 2000 mg/kg and were carefully observed for compound-related morbidity and mortality. If none of the animals died, the following toxicity tests were suspended. If some of the animals died, toxicity tests at doses of 200 and 20 mg/kg were performed. The approximate LD₅₀ values calculated by this method showed little difference between two separate laboratories and were in good agreement with LD₅₀ values reported in the literature. Our toxicological data also showed that LD₅₀ values were about 2–2.5 times the MNLD (maximum non lethal dose) in acute oral and dermal toxicity. This meant that a chemical could be regarded as having an LD₅₀ of about 4000 mg/kg or higher when there was no mortality at the dose of 2000 mg/kg. A chemical with such low toxicity would not require further testing for lethal effects. Therefore, this simple method combining the fixed-dose procedure with the limit test is suitable for determination of approximate LD₅₀ values of chemicals and for screening for necessity for classical full LD₅₀ test using many animals.This work was supported by a grant from Ministry of Health and Welfare in Japan (No. 467 and 511)     

Ruptured congenital aneurysm of the sinus of valsalva in the aged

Ruptured aneurysm of the sinus of Valsalva is a rare cardiac lesion. A ruptured aneurysm of the sinus of Valsalva in the right ventricle of a 64-year-old man was successfully repaired. The patient was admitted to the hospital with high fever and chest oppression. Diagnosis was made by two dimensional echocardiography, cardiac catheterization, and cardiac angiography. An aortotomy, main pulmonary arteriotomy, and right ventriculotomy were performed. There was no VSD, and the aneurysm originated from the right coronary sinus, rupturing into the right ventricle inlet portion. The ruptured aneurysm of the sinus of Valsalva was closed with a Dacron patch from inside the aorta. He is doing well after surgery. There was no heart murmur. CTR decreased and pulmonary blood flow fell to a normal value. As far as we know, this patient is the second oldest patient in Japan with surgical repair.     

Epidemiological studies of air pollution and health effects in areas near roadways with heavy traffic in Tokyo]

Recent concern regarding health effects of air pollution in Japan has concentrated mainly on traffic-induced air pollution and its health effects in large cities. In Japan, where many people in large cities have been living near major roadways, the increase of automobile exhaust due to heavy traffic congestion will predictably cause a greater impact on people living near major roadways. We surveyed the characterization of residential suspended particulate matter (SPM) and nitrogen dioxide (NO2) concentrations along the major roadways in Tokyo, along with a health survey on the respiratory conditions of residents living in the same area, to examine the relationships between indoor pollutant levels, prevalence of respiratory symptoms and distance from roadways. The environmental monitoring was conducted in five phases. Using a newly developed SPM sampler and NO2 filter badge, continuous 4 day (96 hours) measurements were conducted in two hundred residential homes for four weeks. NO2 was measured in the living room, kitchen and outside of each home, while SPM was monitored in the living room. Health information was collected in October 1987 using ATS-DLD self-administered questionnaires. Of the 1,093 homes investigated, responses from 805 homes were received. The following results were obtained. SPM and NO2 concentrations showed large variations. Indoor pollution levels mostly depended on indoor sources, i.e. cigarette smoking and unventilated space heaters, and the effects of those indoor sources were influenced by the building structure with respect to air tightness. An association between increase in pollutant levels and the distance from the roadway was observed. However its effect is small compared to indoor source effects. The prevalence rate of respiratory symptoms was higher in those areas nearest roadways with heavy traffic both in children and adults. These results suggest the presence of a relationship between automobile exhaust and health effects.