Effect of low-level clenching and subsequent muscle pain on exteroceptive suppression and resting muscle activity in human jaw muscles.

OBJECTIVE: To investigate the effects of muscle fatigue induced by low-level isometric jaw-clenching and subsequent glutamate-evoked muscle pain on the exteroceptive suppression (ES) response and resting electromyographic (EMG) activities in human jaw muscles. METHODS: The resting EMG activity and the ESs were recorded before (baseline), after low-level jaw-clenching (Post1), after subsequent glutamate or isotonic saline injections into the left masseter (Post2), and 60 min after the clenching (Post3) in 23 healthy volunteers. RESULTS: The late ES (ES2) showed more inhibition at Post1 compared with baseline (P<0.05). It was less inhibited after both types of injections (Post2), and increased at Post3 again (P<0.05) with no significant difference between the glutamate and isotonic saline sessions. The resting EMG activity increased at Post1 and Post2 (P<0.05). The glutamate injection further increased the resting EMG activity in the injected muscle (P<0.01). CONCLUSIONS: Muscle fatigue influences inhibitory reflex pathways in jaw-closing muscles and subsequent acute muscle pain potentiates the local increase in the resting EMG activity of the painful muscle. SIGNIFICANCE: Muscle fatigue which can be observed in patients with oral dysfunctions may interact with nociceptive regulation and influence the clinical presentation of jaw symptoms and function.     

Incidence and prognostic factors of Japanese breast cancer patients with bone metastasis

Background Few previous studies have analyzed the incidence of bone metastases in a defined population of Japanese breast cancer patients and their prognosis after chemotherapy. Methods This is a retrospective cohort study. We investigated 695 patients who underwent surgery for breast cancer. The strategy of adjuvant therapy was as follows. Patients with both estrogen receptors (ERs) and progesterone receptors (PgRs) had endocrine therapy as initial adjuvant therapy (n = 239). Patients with neither ERs nor PgRs had chemotherapy. When metastasis to other organs, including bone, was identified, patients received chemotherapy. The survival rates after surgery and after the onset of bone metastasis, as well as the incidence of bone metastasis, were calculated. We also evaluated the prognostic and predictive factors. Results Bone metastases developed in 148 of 695 patients. All 148 received chemotherapy, and 121 of them developed spinal metastases. The 5-year survival rate after bone metastases was 26.1%. Prognostic factors for bone metastases were visceral metastases and PgR status. Cord compression was observed in 17 of the 148 patients, with the thoracic spine being the most common. The 1-year survival rate for patients with bone metastases who received chemotherapy was 66.3%, whereas that of patients with paralysis after spinal metastases was 17.6%. Within 6 months of the development of spinal cord compression, 70.6% of the patients died. Conclusions We reported the incidence and prognostic factors for a defined population of Japanese breast cancer patients with bone and spinal metastases. Our results suggest that the expected survival time for patients with paralysis who received adequate endocrine therapy or chemotherapy is generally poor. However, to detect a predictive factor of long survival after paralysis and establish the indications for surgery, a comparative study among large groups of patients with paralysis and with different backgrounds is necessary.     

Surgical treatment for intrathoracic aneurysm of the innominate artery in an 83-year-old asymptomatic woman

Aneurysm of the innominate artery is uncommon compared with other peripheral aneurysms, and holds the potential for rupture, embolization, or thrombosis as well as various complications caused by compression to the adjacent structures. The most effective treatment for this condition is surgical resection, but the earlier reports described high mortality rates. We report the case of an 83-year-old asymptomatic woman with an aneurysm in the innominate artery, which was successfully resected and repaired with the use of modern surgical techniques of hypothermic circulatory arrest and selective cerebral perfusion. Aggressive surgical intervention should be employed despite the fact that a patients is asymptomatic.     

Satisfactory Remission Achieved by PUVA Therapy in Langerhans Cell Hisiocytosis in an Elderly Patient

Langerhans cell histiocytosis is currently regarded as a reactive proliferative process of Langerhans cells rather than a malignancy. The disease is characterized by Langerhans cell infiltration of skin, lung, bone and other organs. We report a 74-year-old man with Langerhans cell histiocytosis who had generalized hemorrhagic and crusted papules. He also had diabetes insipidus. Because he did not have any severe constitutional symptoms or failure of vital organs, we applied topical PUVA treatment to his skin lesions, which responded well to the therapy. Diabetes insipidus, however, remained, in spite of X ray radiotherapy for the pituiary lesion.     

Chromosomal Mapping of Genetic Locus Associated with Thymus-size Enlargement in BUF/Mna Rats

The thymoma-prone rat of the BUF/Mna strain is a useful model for human thymoma. In this strain thymoma development is regulated by a single autosomal susceptible gene, Tsr-1. At pre-thymoma age, BUF/Mna rats have extremely large thyrauses, when compared to those of other strains of rats. Genetic studies in crosses between BUF/Mna rats with large thymuses and WKY/NCrj rats with small thymuses suggested the presence of a major autosomal gene, Ten-1 , which contributes to thymus enlargement in a backcross population. Linkage studies between Ten-1 and microsatellite markers in backcross rats of (WKY/NCrj×BUF/Mna)Fl×BUF/Mna have led to the localization of Ten-1 in chromosome 1. This result may provide an approach to clone Tsr-1 , which could be allelic to Ten-1.     

Clinical and immunological studies on patients with Graves' disease preoperatively treated with corticosteroids and iodides

The purpose of this study was to evaluate the acute effects of corticosteroid and iodide preoperative therapy in patients with Graves' disease in terms of thyroid function and immunological parameters. The above combination was prescribed for 4 patients who had experienced severe side effects from antithyroid drugs (ATD) in order to reduce the possibility of post-thyroidectomy thyroid storm. Corticosteroids were employed daily for four days, and iodides were given daily for two weeks prior to thyroidectomy. The free T₃ values decreased rapidly to euthyroid levels following the administration of both drugs, although the free T₄ values were still much higher than normal in 3 of the 4 patients at the time of surgery. By comparison, 3 of 8 patients treated with ATD also had thyroid hormone levels above normal. Studies of lymphocyte subsets revealed that the percentage of helper T cells was significantly less in the corticosteroidiodide treatment group than in the control and ATD groups. It is thus possible that postoperative thyroid storm might be prevented through corticosteroid-iodide therapy by virtue of the reduction of free T₃ values to within the normal range by the time of surgery. The acute suppression of helper T cells was another result of this form of therapy observed.     

Surgical treatment for the recurrence of colorectal cancer

We report the results of a retrospective study conducted on patients who developed recurrence following surgery for colorectal cancer, and present a practical plan to improve the survival rates. Of 974 patients who underwent surgery for colorectal cancer in our hospital during the 20 years between 1974 and 1993, 152 developed recurrence, as local recurrence in 70 (7.2%), as liver metastasis in 47 (4.8%), and as pulmonary metastasis in 35 (3.6%). The number of patients who underwent reoperation or curative resection was 54 (77.1%) and 13 (24.1%), respectively, of those with local recurrence, 16 (34.0%) and 6 (37.5%) of those with liver metastasis, and 6 (17.1%) and 6 (100.0%) of those with pulmonary metastasis. The 3- and 5-year survival rates were 13.4% and 8.9%, respectively, after reoperation for local recurrence, 14.4% and 0%, after reoperation for liver metastasis, and 53.3% and 53.3% after reoperation for pulmonary metastasis. Although evaluation was difficult owing to the small number of patients with lung metastasis, resection of a pulmonary lesion resulted in a good outcome. Furthermore, a significant difference in 3- and 5-year survival rates was observed between patients who underwent reoperation and those who underwent conservative treatment, for whom the survival rates were 0% and 0% following local recurrence, 4.6% and 0% following liver metastasis, and 0% and 0% following lung metastasis, at 3 and 5 years, respectively. These findings indicate that aggressive surgery for recurrence may result in a better outcome.     

A study on the development of a filing system for funduscopic images with a personal computer for Twin AMHTS

A filing system for ocular fundscopic image data was developed by using a personal computer for the Twin AMHTS. The development of the system was tried as one of the data transfer system including image data between two similar AMHTSs named the Twin AMHTS through the information network system. The filing system is capable of storing 26782 data of ophthalmoscopic pictures with a data compression mode by using a magneto-optical disk (MOD) whose storage capacity of both sides is 616 MB. It takes no long time for retrieval and display of the image data in the filing system. Good quality of compression and decompression obtained and reproducibility of the ocular fundus picture is favorable regardless of normal or abnormal cases. As a result, it is suggested that the developed system has practical utility although it requires more improvement.     

Induction of NADPH-diaphorase activity in the hippocampus in a rat model of cerebral ischemia and ischemic tolerance

Preconditioning of the brain with sublethal ischemia induces tolerance to subsequent lethal periods of ischemia (ischemic tolerance). In this study, we used NADPH-diaphorase histochemistry to investigate the postischemic changes of nitric oxide synthase (NOS) in the hippocampus in a rat model of cerebral ischemia and ischemic tolerance. Forebrain ischemia was induced by 4-vessel occlusion for 3 min as an ischemic preconditioning. Three days after the preconditioning or sham operation, second ischemia was induced for 6 min. A transient increase in NADPH-diaphorase activity, beginning after 2 h and maximal after 1 day, was observed in CA1 pyramidal neurons of rats subjected to 3 min of preconditioning ischemia as well as 6 min of subsequent ischemia both with and without preconditioning. In addition, expression of NADPH-diaphorase activity was seen in reactive glial cells in the damaged CA1 region of animals subjected to 6 min of ischemia without preconditioning. Thus, direct involvement of increased NADPH-diaphorase activity in ischemic tolerance was not suggested because the increased NADPH-diaphorase activity preceded the induction of ischemic tolerance which takes place 1–7 days after preconditioning. However, the present findings suggest that the induction of neuronal NADPH-diaphorase activity occurs in response to cerebral ischemia.     

Type classification of anomalous pancreaticobiliary junction by ERCP

The role of endoscopic retrograde cholangiopancreatography (ERCP) in the preoperative assessment of anomalous pancreaticobiliary junction was retrospectively evaluated in 74 consecutive patients (19 males and 55 females; aged 0–80 years). Sixty-three patients had congenital biliary dilatation and 11 did not. Type classification of congenital biliary dilatation was possible by ERCP alone in 45 patients (71%). The main causes of classification failure were previous bilio-enteric anastomosis and restriction of postural changes during ERCP due to general anesthesia in pediatric patients. Classification of anomalous junction was possible in 69 patients (93%). Technical difficulty in ERCP caused classification failure in 5 patients. Neoplastic lesions were found in 12 patients (16%) and all but 1 were correctly diagnosed by ERCP. We conclude that ERCP plays an important role in the preoperative diagnosis and type classification of anomalous pancreaticobiliary junction and congenital biliary dilatation.