Previous clinical and experimental studies suggested that invasion of the brain by metastatic melanoma may follow the external surfaces of vascular channels, that is, angiotropic extravascular migratory metastasis. Such angiotropic invasion seemss analogous to that of neoplastic glial invasion of the nervous system. We, therefore, have retrospectively investigated 20 primary melanoma cases and their respective metastatic brain lesions. The following parameters were analyzed in each primary melanoma: presence of angiotropism, Breslow thickness, Clark level, mitotic rate, sentinel lymph node (SLN) status, and time interval between the primary lesion and the metastasis. The metastatic brain lesions were examined for the presence of angiotropism. Of the 20 cases, 14 showed angiotropism in the primary lesion. The angiotropic group had a significantly deeper Breslow thickness (median 4.4 mm vs. 1.4 mm, P < 0.01) and was more mitotically active (median 11 vs. 4.7 mitoses/mm, P = 0.04). Interestingly, the angiotropic group had an average time lapse of 33 months from the primary lesion to the brain metastasis, whereas the nonangiotropic group had a 57-month time interval. Although the Kaplan-Meier analysis failed to show a survival difference in this small cohort (P = 0.235), there was a trend toward significance. Seven of 20 brain metastases showed angiotropism; however, no significant correlation between angiotropism in the primary melanomas and the corresponding metastatic lesions could be demonstrated. Indeed, angiotropism in the brain metastases was difficult to assess because the available material were generally small partial biopsy samplings and many showed conspicuous necrosis. Ten melanoma patients underwent SLN biopsy. The 3 of 6 positive cases in the angiotropic group had an average time lapse of 32 months from the primary lesion to the brain metastasis, whereas the 4 positive SLN biopsies in the nonangiotropic group had an average of 63 months. This preliminary study of angiotropism in primary melanomas and their corresponding brain metastasis shows a striking trend suggesting that angiotropism in primary melanomas may predict the rapid development of brain metastases. This study also has demonstrated the difficulty in studying angiotropism in melanoma brain metastases because of small sample sizes and abundance of necrotic tissue. The authors are in the process of collecting larger and more representative numbers of melanoma brain metastases for further investigations.

Prenatal stress, psychologically and metabolically, increases the risk of obesity and diabetes in the progeny. However, the mechanisms of the pathogenesis remain unknown. In adult mice, stress activates NPY and its Y2R in a glucocorticoid-dependent manner in the abdominal fat. This increased adipogenesis and angiogenesis, leading to abdominal obesity and metabolic syndrome which were inhibited by intra-fat Y2R inactivation. To determine whether stress elevates NPY system and accelerates adipogenic potential of embryo, here we “stressed" murine embryonic stem cells (mESCs) in vitro with epinephrine (EPI) during their adipogenic differentiation. EPI was added during the commitment stage together with insulin, and followed by dexamethasone in the standard adipogenic differentiation medium. Undifferentiated embryonic bodies (EBs) showed no detectable expression of NPY. EPI markedly up-regulated the expression NPY and the Y1R at the commitment stage, followed by increased Y2R mRNA at the late of the commitment stage and the differentiation stage. EPI significantly increased EB cells proliferation and expression of the preadipocyte marker Pref-1 at the commitment stage. EPI also accelerated and amplified adipogenic differentiation detected by increasing the adipocyte markers FABP4 and PPARγ mRNAs and Oil-red O-staining at the end of the differentiation stage. EPI-induced adipogenesis was completely prevented by antagonists of the NPY receptors (Y1R+Y2R+Y5R), indicating that it was mediated by the NPY system in mESC's. Taken together, these data suggest that stress may play an important role in programing ESCs for accelerated adipogenesis by altering the stress induced hormonal regulation of the NPY system.

No abstract

Perineural granulomas in cutaneous sarcoidosis have been rarely reported and their clinical significance has yet to be evaluated. Recently, a 27-year-old male presented with multiple pink papules on the flank and lower back, accompanied by a painful, burning sensation. Biopsies revealed well-defined granulomas, consistent with sarcoidosis, in the dermis and involving small cutaneous nerves. We hypothesized that perineural granulomas may be an under-recognized feature of cutaneous sarcoidosis and may be responsible for sensory disturbances. We reviewed cases from 29 consecutive patients with cutaneous sarcoidosis. Perineural granulomas were identified in 18/29 (62%) patients and in 22/40 (55%) biopsies. Perineural granulomas were identified in 7/9 biopsies from the proximal upper extremity, 1/3 from the distal upper extremity, 7/12 from the head and the neck, including 4/4 from the nose, 5/9 from the back, 1/2 from the flank and 1/1 from the proximal lower extremity and 0/4 from the distal lower extremity. The anatomical distribution is similar to sarcoidosis small-fiber neuropathy (SSFN), in which sarcoidosis patients without evident skin lesions experience sensory disturbances of unknown etiology involving the face, the proximal extremities and the trunk. Our results indicate perineural granulomas in cutaneous sarcoidosis are more common than previously appreciated, primarily involve the head, the proximal upper extremities and the back, and may be responsible for neurological manifestations.