Thyrotropin-releasing hormone stimulates NR4A3 expression in the pituitary thyrotrophs of proestrus rats.

The secretion of several hypothalamic peptide hormones is activated during the preovulatory period. Hypothalamic thyrotropin-releasing hormone (TRH) is one such hormone with reproductive and/or metabolic significance. However, it remains unclear whether thyroid-stimulating hormone (TSH)-producing thyrotrophs are produced during the preovulatory period. We previously found a transient increase in the expression of the nuclear receptor NR4A3, a well-known immediate early gene, in the proestrus afternoon in the anterior pituitary glands of rats. To investigate the relationship between TRH secretion and pituitary NR4A3 expression during proestrus, we used proestrus and thyroidectomized rats to identify NR4A3-expressing cells and examined the regulation of Nr4a3 gene expression via the hypothalamus-pituitary-thyroid (HPT) axis. The percentage of NR4A3-expressing cells increased in thyrotrophs at 14:00 h of proestrus. Incubation of rat primary pituitary cells with TRH transiently stimulated Nr4a3 expression. Thyroidectomy to attenuate the negative feedback effects led to increased serum TSH levels and Nr4a3 gene expression in the anterior pituitary, whereas thyroxine (T4) administration conversely suppressed Nr4a3 expression. Additionally, the administration of T4 or TRH antibodies significantly suppressed the increase in Nr4a3 expression at 14:00 h of proestrus. These results demonstrate that pituitary NR4A3 expression is regulated by the HPT axis, and that TRH stimulates thyrotrophs and induces NR4A3 expression during the proestrus afternoon. This suggests the potential involvement of NR4A3 in the regulation of the HPT axis during pre- and post-ovulatory periods.

[A case of tuberculous aneurysm of subclavian artery occurred in the course of treatment for miliary tuberculosis].

This case is a 56-year old woman. Steroids were being administered perorally after a thymectomy for myasthenia gravis. A fever of 38-39 degrees Celsius appeared during night, an abnormal shadow showed up on a chest X-ray and the patient was hospitalized. Gaffky No. 2 acid-fast bacilli were detected in the patient's sputum and the chest CT showed diffuse granular-like shadow, the patient was diagnosed as miliary tuberculosis and treatment with combined use of INH, RFP, EB, and PZA was started. Subsequently, fever started to subside and the miliary shadow on chest X-ray improved, however, six weeks after the start of treatment, hoarseness and dysphagia appeared. From the cervical CT and cervical angiography findings, the diagnosis of right subclavian artery impending ruptured aneurysm was made. Because the patient's sputum was acid-fast bacilli positive and because the patient had undergone thymectomy, it was decided that it would be difficult to treat her by a thoracotomy again. Therefore, a right subclavian artery stent insertion, right subclavian artery-right common carotid artery bypass creation operation was carried out with the objective of blocking the flow of blood to the aneurysm. The hoarseness and dysphagia improved post-operatively and the patient's progress is being monitored. Tuberculous aneurysms are a rare affection and they are mostly discovered when the autopsy is done, however, this case was diagnosed due to the manifestation of subjective symptoms. While this case was not diagnosed histopathologically, it is envisaged from the clinical progress that this was a tuberculous subclavian aneurysm complicated during the treatment for miliary tuberculosis.

The effects of inhalation of diesel exhaust on murine mycobacterial infection.

The authors investigated the effects of inhalation of diesel exhaust (DE) on murine mycobacterial infection in vivo. Eight-week-old female BALB/c mice were exposed to DE (3 mg/m3 of diesel exhaust particles [DEPs]) for 1 month, 2 months, or 6 months (for 7 hours a day, 5 days a week). Control mice were housed in a clean room for the same periods. On the day following the last DE exposure, control mice and DE-exposed mice were aerially infected with Mycobacterium tuberculosis (1 x 10(6) colony-forming units (CFU), Kurono strain). At 7 weeks after mycobacterial infection, the authors examined the lung tissues for histopathological changes and performed reverse transcriptase-polymerase chain reaction (RT-PCR) to measure the messenger RNA (mRNA) expression of several proinflammatory cytokines and inducible nitric oxide synthase (iNOS). Then, the homogenates of lungs and spleens were cultured on 1% (v/v) Ogawa's egg slant medium, and after a 4-week incubation period at 37 degrees C, colonies on the medium were counted. After 1 month of DE exposure, the mycobacterial infection had slightly ameliorated. After 2 months of DE exposure, the expression levels of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, IL-12p40, interferon (IFN)-gamma, and iNOS mRNAs were slightly increased. However, after 6 months of DE exposure, the expression levels of IL-1beta , IL-12p40, IFN-gamma, and iNOS mRNAs were decreased, and the infection as measured by increased lung burden (CFU) actually increased. These results indicate that long-term DE exposure may increase pulmonary mycobacterial burden.

[Clinicopathological analysis of patients with idiopathic pulmonary fibrosis which became acutely exacerbated after video-assisted thoracoscopic surgical lung biopsy].

Nine patients undergoing video-assisted thoracoscopic surgical (VATS) lung biopsy over a five-year period from 1997 to 2001 with the ultimate diagnosis of usual interstitial pneumonia without underlying connective tissue disease were identified. In two of nine patients, acute exacerbation occurred six days after VATS lung biopsy. We reviewed the clinical records and pathology of all nine cases, and found that the two cases of exacerbation had higher peripheral white blood cell counts and KL-6, lower PaO2, VC and FEV 1, and a longer inhalation of FIO 2 = 1.0 during VATS, and needed a longer period of chest drainage after VATS. Abundant inflammatory cell infiltration and fibroblastic foci were observed in the exacerbation cases. Thus, patients with usual interstitial pneumonia of the idiopathic type, who have high disease activity and low pulmonary function, may be at high risk of acute exacerbation following VATS lung surgery.