Comparative studies on bioaccumulation of PCDDs and PCDFs in C57BL/6 and DBA/2 mice treated with a mixture by oral administration.

To determine the cause of the extremely high accumulative potency of OCDD in human tissues, EROD activity and accumulation of 2,3,7,8-chlorine substituted PCDDs and PCDFs in liver of C57BL/6 and DBA/2 mice administered these chemicals orally were measured during a period of 28 days. Consequently, in both C57BL/6 mice with high EROD induction and DBA/2 mice with low EROD induction, there was no high accumulation of OCDD similar to that observed in human tissues. In addition, the C57BL/6 mice accumulated larger amounts of these chemicals in their liver than did the DBA /2 mice.

Pollution by PCDDS and PCDFS in sediment from freshwater fish culture ponds near incineration sites for metal reclamation in Wan-Li, Taiwan, Republic of China.

Sediment samples from nine culture ponds for freshwater fish at and near waste incineration sites for metal reclamation in Wan-Li, southern Taiwan, Republic of China were analyzed for PCDDs and PCDFs by HRGC-HRMS. Four of nine samples were heavily polluted by PCDDs and PCDFs, indicating the latter to be dominant. The total TEQ concentrations of PCDDs and PCDFs in the four samples were in the range of 257 to 12200 pg/g dry weight. In addition, the levels corresponded to those of surface soil samples from the same waste combustion areas.

[Severe cases of pulmonary tuberculosis required mechanical ventilation].

We report severe cases of pulmonary tuberculosis with respiratory failure who required mechanical ventilation. Of 99 patients with pulmonary tuberculosis admitted to Daido Hospital from November 1991 to November 1993, 6 patients had been mechanically ventilated. Four of these 6 patients were vagrants and had long delay from onset of the symptom to the admission. Chest X-rays of ventilated patients showed bilateral, extensive shadows consistent with those of typical pulmonary tuberculosis, and a large number of acid-fast bacilli were detected in their sputa. Though all ventilated patients except one HCV carrier had no underlying disease, they showed remarkable emaciation and malnutrition. They also showed weak PPD-skin reactions and reduced number of lymphocytes that suggested immunological disorders. Four cases have recovered, so we conclude that mechanical ventilation is necessary and useful for the treatment of severe cases of pulmonary tuberculosis.

[Nontuberculous mycobacterial disease in a general hospital].

Annual incidence of nontuberculous mycobacterial (NTM) disease has been gradually increasing in the last 10 years in Japan. It is likely to encounter this disease not only in hospitals specialized in mycobacterial diseases but also in general hospitals. NTM were isolated from 97 cases between January 1990 and June 1996 at our hospital. Out of them, 41 patients were diagnosed as NTM disease. Mycobacterium avium complex (MAC) was the most frequent pathogens (68.3%) and M. kansasii (22%) was the next. Other pathogens were M. chelonae (4.9%), M. fortuitum (2.4%) and M. szulgai (2.4%). Results obtained in our hospital were very similar to the rates which have been reported previously. Patients with MAC infection showed relatively poor prognosis (eight patients were died out of 28 patients with MAC) in this study compared with the cases reported in previous papers, and this result could be explained by the severity of illness when they were admitted to our hospital, the insufficiency of the initial treatment which should be started with the combined use of three to four antibacterial drugs including clarithromycin, and to a low dosage of clarithromycin compared with conventionally adopted dosage. Unlike tuberculosis, human to human transmission is considered to be negligible in the case of NTM disease, and general hospitals are able to provide medical care to the patients with NTM disease. Rather, if general hospitals which are located in the region near to the patients residence can play more active role in the treatment of NTM disease, it would be more beneficial to patients requiring long-term follow-up observation. Based on the result that similar therapeutic results were obtained for infections with other NTM as reported in previous papers, it is indicated that general hospitals are able to provide medical care to patients with NTM disease if therapeutic regimens recommended by specialist are sufficiently understood and applied.

Effects of castration and testosterone treatment on the development and involution of the bursa of fabricius and the thymus in the Japanese quail.

We investigated the effects of castration on the development of lymphoid organs (bursa of Fabricius, thymus, and spleen) in the Japanese quail during 4-8 weeks of age under a long photoperiod (16L:8D) and the effect of testosterone implantation on the involution of the lymphoid organs under long (16L:8D) and short (8L:16D) photoperiods. Under 16L:8D, the bursa of Fabricius and thymus in intact quail grew rapidly and reached a peak at 6 weeks of age and regressed thereafter. In contrast, development of the lymphoid organs in castrated quail was well correlated with the body growth. Testosterone treatment induced a significant reduction in relative bursal weight to body weight at 6 weeks of age under 16L:8D and 8 weeks of age under 16L:8D and 8L:16D, in relative thymus weight at 6 weeks of age under 16L:8D and 8L:16D, and in relative spleen weight at 6 weeks of age under 8L:16D. Thus, we conclude that gonadal hormones play an important role in the development and involution of lymphoid organs.

Effects of photoperiods on the weights of bursa of Fabricius and thymus in Japanese quail.

Effects of photoperiods on the growth of the bursa of Fabricius and the thymus were investigated in male (1-8 weeks after hatching) and female (5-7 weeks after hatching) Japanese quail. In males from hatching to 4 weeks of age, the bursal growth was not affected by photoperiod. However, the growth pattern was different between long and short days after 4 weeks of age, i.e., the bursal weight under long days (LD 16:8) increased rapidly until 6 weeks of age and regressed thereafter, whereas it continued to increase under short days (LD 8:16), keeping a constant ratio to body weight. The growth of the thymus showed a similar pattern to that of the bursa of Fabricius. The age for the thymus to reach the maximum weight under LD 16:8 was almost the same as that for the bursa. In LD 8:16, thymus weight increased until 6 weeks and thereafter remained constant. In females, bursa of Fabricius and thymus weights decreased from 6 to 7 weeks under LD 16:8, which was coincided well with the rapid oviduct growth, whereas the organ weights increased under short days. Thus, it was clearly shown that the growth pattern of lymphoid organs is affected by photoperiods in both male and female Japanese quail.

Direct MR arthrography of plica synovialis mediopatellaris.

OBJECTIVE: To evaluate the efficacy of direct MR arthrography for diagnosing plica synovialis mediopatellaris (PSM). MATERIAL AND METHODS: Twenty-two knees of 19 patients were examined by direct MR arthrography. In 19 of those knees, field-echo T2*-weighted transaxial images were obtained with intra-articular administration of 40 ml of saline ("direct MR arthrography"). In the other 3 knees, T1-weighted transaxial images were obtained with intra-articular administration of 40 ml of gadopentetate dimeglumine. Conventional MR images were evaluated prior to direct MR arthrography in 12 of the 22 knees. The results of direct MR arthrography and conventional MR imaging were compared with the arthroscopic findings. RESULTS: Direct MR arthrography demonstrated 17 of 19 PSMs proved on arthroscopy. The features of 16 PSMs on direct MR arthrography corresponded accurately with the arthroscopic classification. Conventional MR demonstrated only 3 plicae. CONCLUSION: Direct MR arthrography enabled accurate diagnosis of PSMs and could replace diagnostic arthroscopy.