Regeneration of ring-shaped lateral meniscus after partial resection of discoid meniscus with anterior cruciate ligament reconstruction

INTRODUCTIONThe ring-shaped lateral meniscus is very rare. Although it is essentially known as a congenital anomaly, a central tear in an incomplete discoid meniscus or an old bucket-handle tear in a meniscus may be easily mistaken for a ring-shaped meniscus. We experienced a ring-shaped lateral meniscus that regenerated after partial resection of a discoid meniscus together with anterior cruciate ligament (ACL) reconstruction.PRESENTATION OF CASEA 37-year-old female patient still experienced unrelenting knee pain 6 months after ACL reconstruction and partial meniscectomy of a discoid lateral meniscus. A repeat arthroscopy was performed. The lateral tibial plateau was covered in the form of a ring by meniscus-like tissue. The meniscus-like tissue appeared to have regenerated inward toward the center from the stump after the partial meniscectomy and was connected from the anterior to posterior horn, forming an interhorn bridge. Partial meniscectomy was repeated. Histologically, the regenerated tissue was not meniscal, but comprised mature fibrocartilage; macroscopically; however, it was very similar to meniscal tissue. Two years after the initial operation, the patient had no complaints and experienced full return of function.DISCUSSIONThe reason for such regeneration is unknown, but may have been attributed to the specific intra-articular environment that developed after the ACL reconstruction.CONCLUSIONThis is the first report of regenerative development of a ring-shaped lateral meniscus. When a ring-shaped lateral meniscus is diagnosed, we must accurately determine whether it is a true congenital anomaly in consideration of the present case.     

Up-regulation of c-myc gene expression following focal ischemia in the rat brain

Abstract

Changes in gene expression including that ofc-fos occur following cerebral ischemia. Proto-oncogenes c- myc and s-myc and oncosuppressor gene p53 are known to induce apoptosis in some types of cells, whereas proto-oncogene bcl-2 inhibits apoptosis. Possible induction of mRNAs for c-myc, N-myc, s-myc, c-fos, p53 and bcl-2 was examined following focal ischemia in the rat anterior cortex, hippocampus, thalamus and cerebellum by Northern blot analysis. Animals were decapitated 1, 2, 6, 12, and 24 hours following the left middle cerebral artery (MCA) occlusion. In sham-operated control rats, the mRNAs for c- myc, N-myc, c-fos and p53 were present in the anterior cortex, hippocampus; thalamus on both sides, and in the cerebellum, whereas those for s-myc and bcl-2 were not The c-myc gene expression was rapidly and markedly induced by the MCA occlusion in the ipsilateral anterior cortex, hippocampus and thalamus in a time-dependent manner. In these regions, the c-fos gene expression was also induced as early as 1 hour after the MCA occlusion. The p-53 mRNA was induced in the ipsilateral hippocampus at 24 hours after MCA occlusion. In contrast, mRNAs for N-myc, s-myc and bcl-2 were not induced following MCA occlusion. These results indicate a possibility that high-level expression of the c-myc gene may be involved in the ischemic cellular events including apoptosis. [Neurol Res 1996; 18: 559-563]     

Clinical outcomes and nadir prostate-specific antigen (PSA) according to initial PSA levels in primary androgen deprivation therapy for metastatic prostate cancer

Purpose

To investigate the clinical outcomes of metastatic prostate cancer patients and the relationship between nadir prostate-specific antigen (PSA) levels and different types of primary androgen deprivation therapy (PADT). This study utilized data from the Japan Study Group of Prostate Cancer registry, which is a large, multicenter, population-based database.

Methods

A total of 2982 patients treated with PADT were enrolled. Kaplan–Meier analysis was used to compare progression-free survival (PFS) and overall survival (OS) in patients treated using combined androgen blockade (CAB) and non-CAB therapies. The relationships between nadir PSA levels and PADT type according to initial serum PSA levels were also investigated.

Results

Among the 2982 enrolled patients, 2101 (70.5 %) were treated with CAB. Although CAB-treated patients had worse clinical characteristics, their probability of PFS and OS was higher compared with those treated with a non-CAB therapy. These results were due to a survival benefit with CAB in patients with an initial PSA level of 500–1000 ng/mL. Nadir PSA levels were significantly lower in CAB patients than in non-CAB patients with comparable initial serum PSA levels.

Conclusions

A small survival benefit for CAB in metastatic prostate cancer was demonstrated in a Japanese large-scale prospective cohort study. The clinical significance of nadir PSA levels following PADT was evident, but the predictive impact of PSA nadir on OS was different between CAB and non-CAB therapy.

     

Rapid determination of viral RNA sequences in mosquitoes collected in the field

A method for rapid determination of viral RNA sequences (RDV) was applied to homogenates of Aedes aegypti collected in Thailand in an area in which dengue fever (dengue hemorrhagic fever) is endemic, using the mosquito cell line C6/36. Nucleic acid sequences of dengue virus type 4 and cell fusing agent virus were detected. This RDV method has the potential to become a standard method for detection of both known and newly emerging, unknown mosquito-borne viruses.     

Thromboembolism in lung cancer patients]

We reviewed 649 primary lung cancer patients with special reference to the occurrence of thromboembolism. Thirteen episodes of thromboembolism were detected in 12 (1.8%) of the 649. Eight of the 12 were men, and their mean age was 63. Adenocarcinoma was the predominant cell type. Most patients had an advanced stage of the disease, but in some in the cancer was at an early stage. In 5 cases, the finding of thromboembolisms led to diagnosis of the lung cancer (38.5%). Anticoagulant therapy was performed in 9 cases, of which 8 responded without serious complication. We emphasize the importance of anticoagulant therapy as a therapy indicated for thromboembolism in patients with lung cancer.     

A case of pleomorphic carcinoma of the pancreas showing sequential histological change by immunohistochemical study

Summary Pleomorphic carcinoma of the pancreas is a rare, histologically characterized pancreatic tumor with a rapid and fatal course. We report a case of a resected pleomorphic carcinoma located in the body of the pancreas in a 61-yr-old male. Histological analysis of the resected specimen revealed the coexistence of pleomorphic carcinoma with adenocarcinoma, but the recurrent tumors at autopsy 20 mo later were only of the adenocarcinomatous type. Cells in the adenocarcinomatous component showed a diffuse reactivity for CA19-9, CEA, and cytokeratin, and a focal reactivity for vimentin. In contrast, vimentin was diffusely expressed in pleomorphic lesion. Adenocarcinoma at autopsy expressed CA19-9, CEA, and cytokeratin, but not vimentin. These findings suggest that the recurrent adenocarcinoma may have developed as a consequence of sequential change in the nature of the tumor.     

Cumulative probability of prostate cancer detection in biopsy according to free/total PSA ratio in men with total PSA levels of 2.1–10.0 ng/ml at population screening

Purpose

The aim of this study was to investigate the cumulative probability of prostate cancer detection according to free/total prostate-specific antigen (PSA) ratio in men with PSA levels of 2.1–10.0 ng/ml and also likelihood of detecting clinically insignificant prostate cancer in population-based screening.

Methods

A total of 1,277 men aged between 55 and 69 years with total PSA (tPSA) levels of 2.1–10.0 ng/ml screened in population screening in Kanazawa city and underwent systematic transrectal ultrasonography-guided prostate biopsy between 2000 and 2011 were enrolled. The cumulative probability of prostate cancer detection in biopsy according to age, serum tPSA, and free-to-total PSA (f/t PSA) ratio was investigated. The clinicopathological features of screening-detected prostate cancer were also investigated.

Results

Of the 1,277 subjects in the study population, 320 (25.0 %) were diagnosed with prostate cancer during the observation period. The probabilities of prostate cancer detection at 3 years were 64.5, 41.2, 28.5, and 14.3 % for the men with f/t PSA ratio ≤0.08, 0.09–0.13, 0.14–0.22, and ≥0.23, respectively; the differences in probabilities of prostate cancer detection among men with different f/t PSA ratios were statistically significant. Among 320 patients, 84 (26.3 %) had favorable clinicopathological features that made them suitable for active surveillance. The f/t PSA ratio in unfavorable cancer patients was significantly lower that that in favorable cancer patients.

Conclusion

The present study demonstrated that the f/t PSA ratio was a strong predictor of future cancer detection and unfavorable cancerous features in prostate biopsy in men with total PSA levels of 2.1–10.0 ng/ml at population screening.