Correlation of structure and function in the oxidative phosphorylation system of submitochondrial particles

1. After the centrifugation of sonicated heavy beef heart mitochondria at 75, 000 &#215; g for 10 minutes, the supernatant was centrifuged at 144, 000 &#215; g for 30 minutes. The residue was revealed being composed of vesicular inner membrane fragments (ETPH), about 600 to 1000 &#197;. in diameter, showing a morphological homogeneity and a high capacity of oxidative phosphorylation. 2. The Pia ratio of the ETPH in the presence of succinate and of NADH2 was 1.68 and 2.54, respectively, and the corrected Pia value for O2 gas equilibrium was 1. 01 and 1.40, respectively. 3. The capacity of oxidative phosphorylation in ETPH fraction was parallel to the activity of the oligomycin. sensitive ATPase in these fractions. 4. The P/0 ratio of ETPH was decreased to about 50 % by hypotonic treatment. The decrease of P/0 ratio was restored to the level of about 90 % by incubating the ETPH with ATP and BSA. In the instance where the P/0 ratio was low level in the hypotonic medium, the surface structure of ETPH was observed as a swollen form and the head pieces of the elementary particles were clearly observed in contrast to the solid surface structure of ETPH in the isotonic medium. 5. The P/0 ratio of ETPH was decreased to about 60 % by relatively severe sonication, and after separating the residue from the supernatant, that of the residue decreased further to about 40 %. The P/0 ratio of the residue was restored to the level before the separation on the addition of the supernatant containing oligomycin-insensitive ATPase. 6. A discussion was made on the correlation between the surface structure and the activities at terminal phosphorylation step of ETPH after the simple physico-chemical treatment.</p

Limitation of Using Ultrasonography After Positive Sentinel Lymph Node Biopsy in a Patient with Melanoma in the Detection of Lymph Node Metastasis

Recent studies have shown that complete lymph node dissection (CLND) performed immediately did not improve the overall survival in patients with sentinel lymph node (LN)-positive melanoma. According to these results, nodal observation with ultrasonography becomes standard. However, it still has some limitations for detection of metastatic LNs. A 74-year-old woman was diagnosed with acral lentiginous melanoma of her left sole. The sentinel LN was positive for metastasis, but she refused CLND. Sixteen months after operation, ultrasonography showed an abnormal LN in the inguinal region. There was no other abnormal LNs around the LN. We resected the abnormal LN. The resected LN was black in color, and the adjacent LN that showed normal appearance in ultrasonography was also black. A recent study showed only 6.6% sensitivity in preoperative ultrasonographic detection of metastatic melanoma in a LN. We should keep in mind the limitation of ultrasonography for detection of a metastatic LN

Hematological- and Neurological-Expressed Sequence 1 Gene Products in Progenitor Cells during Newt Retinal Development

Urodele amphibians such as Japanese common newts have a remarkable ability to regenerate their injured neural retina, even as adults. We found that hematological- and neurological-expressed sequence 1 (Hn1) gene was induced in depigmented retinal pigment epithelial (RPE) cells, and its expression was maintained at later stages of newt retinal regeneration. In this study, we investigated the distribution of the HN1 protein, the product of the Hn1 gene, in the developing retinas. Our immunohistochemical analyses suggested that the HN1 protein was highly expressed in an immature retina, and the subcellular localization changed during this retinogenesis as observed in newt retinal regeneration. We also found that the expression of Hn1 gene was not induced in mouse after retinal removal. Our results showed that Hn1 gene can be useful for detection of undifferentiated and dedifferentiated cells during both newt retinal development and regeneration