Effects of a liquid diet on the response properties of temporomandibular joint nociceptive neurons in the trigeminal subnucleus caudalis of growing rats

OBJECTIVE

To investigate whether low mechanical loading on the temporomandibular joint (TMJ) when ingesting a liquid diet affects the response properties of neurons in the trigeminal spinal tract subnucleus caudalis (Sp5C) in growing rats.

MATERIALS AND METHODS

Shortly after weaning, 2-week-old male rats were fed chow pellets (control) or a liquid diet (experimental). Firing activities of single sensory units were recorded from the Sp5C at 4, 5, 7, and 9 weeks. Neurons were functionally classified by their responsiveness to TMJ stimuli. The responses of Class II and III neurons to TMJ stimuli were investigated.

RESULTS

In both neuron classes, the firing threshold in the experimental group was significantly lower than in the control group at all time points, but remained static in the control group throughout the experimental period, whereas it peaked in the experimental group at 4 weeks, decreased at 5 weeks, and remained stable thereafter until 9 weeks. Similarly, the initial firing frequency was significantly higher in the experimental group than in the control group, but remained static in the control group throughout the experimental period, whereas in the experimental group, it was at its lowest at 4 weeks, increased at 5 weeks, and stayed stable thereafter until 9 weeks.

CONCLUSION

Differences in TMJ loading arising from variable diet consistency during growth may affect the functional characteristics of Sp5C neurons.

Subclinical renal tubular acidosis in patients with primary and secondary Sjögren's syndrome: a possible marker of disease progression

Abstract To clarify the prevalence of subclinical renal tubular acidosis (RTA) and its association with clinical and laboratory parameters in primary and secondary Sjögren's syndrome (SS), an acid-loading test was conducted. Subclinical RTA was found in 32% of patients with SS. The prevalence of subclinical RTA in primary and secondary SS was about the same (31.6% and 33.3%, respectively). Significant longer duration of illness, more severely decreased salivary excretion, decreased lymphocyte number, higher serum levels of IgG and IgA, and higher frequency of anti-SS-A (Ro) and SS-B (La) antibodies were found in patients with subclinical RTA. These results suggested that subclinical RTA may be a characteristic manifestation both in primary and secondary SS, along with the progression of immunologic dysfunction, when the illness seemed to be indolent.

Long-term administration of beraprost, an oral prostacyclin analogue, improves pulmonary diffusion capacity in patients with systemic sclerosis

The objective of this study was to assess the effect of beraprost sodium, an oral prostacyclin analogue, on pulmonary function in patients with systemic sclerosis. Seventeen patients, with systemic sclerosis and predicted percent values of carbon monoxide diffusion capacity (%DLCO) of less than 95, received beraprost sodium for at least 12 months. Conventional testing for pulmonary function was performed at 12-month intervals and changes were evaluated with special reference to DLCO. Twelve patients completed the treatment. Nine patients showed improvement in DLCO (12.1 +/- 2.3 to 15.5 +/- 4.4 ml/min/mmHg, P < 0.006) and 10 patients showed an increase in %DLCO (66.6 +/- 11.9 to 87.7 +/- 23.2%, P < 0.004). Total lung capacity, vital capacity and forced expiratory volume remained unchanged. This study showed that DLCO levels in patients with systemic sclerosis improved after the administration of beraprost sodium, probably due to the decrease in pulmonary vascular resistance accompanied by increased cardiac output.

[Crohn's disease with the onset resembling systemic lupus erythematosus]

We described a 37-year-old man with Crohn's disease (CD) resembling systemic lupus erythematosus (SLE) at his disease onset. He was admitted to the municiple Akiru Hospital in October 1986 by fever, aphtous oral ulcerations, sore throat and polyarthralgia. Hematologic examination showed leukocytopenia, lymphocytopenia, positive tests for antinuclear antibody, anti-DNA antibody and LE cell phenomenon. He has had episodes of convulsion and conciousness loss of unknown etiology when he was 17 years old. The diagnosis of SLE was made, and oral medication of prednisolone was started. Several weeks later, most of symptoms and autoantibodies disappeared, although the oral aphtous ulcerations and leukocytopenia remained. In May 1987, he admitted to the other hospital because of bloody vomiting. Endoscopic examination showed the esophagial ulceration, and histology of biopsied-specimen was nonspecific esophagitis. The combination of prednisolone and oral cyclophosphamide or methotrexate was employed thereafter. However, the leukocytopenia, oral aphtous ulceration and esophagial ulceration continued in spite of these treatments. All the immunosuppressive treatment was stopped at March 1992. In October 1995, he admitted to our hospital because of body weight loss and continuous diarrhea with occasional bloody stool. Barium enema and endoscopic examination of the colon revealed the findings compatible with CD. The patient responded favorably to methylprednisolone pulse therapy followed by oral sulphasalazine. This case indicated that cases with inflammatory bowel diseases like CD could show similar clinical signs and symptoms to SLE, and in some cases of CD might satisfied the classification of criteria for SLE.

[Lobenzarit disodium (CCA)--induced diabetes insipidus in a patient with rheumatoid arthritis]

A 44-year-old female with 16-year history of rheumatoid arthritis visited Akiru Hospital with complaints of a thirst, a dry mouth and a general fatigue. One week prior to admission, the patient manifested excessive thirsty feeling, a body weight loss and a sleepless by the polyuria. She has been given 5-10 mg of prednisolone and 240 mg of lobenzarit disodium (CCA) in a day for 11 months. A hematologic examination showed no abnormality, and the examination of her serum showed the following values: BUN, 9.3 mg/dl; creatinine, 0.9 mg/dl; sodium, 139 mEq/l; chloride, 102 mEq/l; potassium, 3.9 mEq/l; osmolality, 290 mOsm/l. Plasma antidiuretic hormone (ADH) level increased slightly (6.0 pg/ml). Examination of her urine revealed specific gravity, 1.005; no trace of glucose, protein, blood and ketones; normal sediment; and osmolality, 209 mOsm/l. The patient was given exogenous ADH (10 units of vasopressin tannate in oil, intramuscularly) to obtain a diagnosis, and she was found to be unable to concentrate her urine more than 1.008 in the specific gravity. A water restriction, as a test for diabetes insipidus, also failed to concentrate her urine in the specific gravity and in the osmolality. Together with these findings, the patient was diagnosed to be a diabetes insipidus, and CCA was seemed to account for the disease. This unfavorable effect of CCA appeared to be reversible, since the patient recovered her urinary concentrating ability after the medication of CCA was discontinued.