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Tomoyasu Kato

Publications and source records attributed to Tomoyasu Kato.

6 recordsLinked to original sources
PubMed2005

Calcifications in mucinous and serous cystic ovarian tumors.

Mucinous cystic ovarian tumors sometimes contain calcifications, but the frequency and significance of such calcifications in diagnostic radiology are not well understood. We therefore retrospectively investigated the radiological and histopathological evidence of calcifications in 44 cases of ovarian mucinous cystic tumors (22 benign, 13 borderline, and 9 malignant) and 21 cases of ovarian serous cystic tumors (6 benign and 15 malignant) in which a non-contrast CT scan was performed. The shape and distribution of the calcifications in the mass lesion were assessed both radiologically and histopathologically. Calcifications were noted in 34.1% of mucinous cystic tumors on CT scans and 56.8% in histopathological studies, and they were found in two locations, intramural and intra-cystic, according to the histopathological findings. Intramural calcifications were frequent in benign tumors, and intra-cystic calcifications were frequent in proliferating tumors. Calcifications (psammoma bodies) were noted in 4.7% of serous cystic tumors on CT scans and 14.3% in histopathological studies. CT was not sufficiently sensitive in the detection of intra-cystic calcification in mucinous tumors and psammoma bodies in serous tumors. However, the presence of intramural calcifications may be a good indicator of mucinous tumors. Understanding the frequency and morphology of the calcifications in these neoplasms is one of the keys to making a correct diagnosis.

Adult↗
PubMed2003

Fascial structures and autonomic nerves in the female pelvis: a study using macroscopic slices and their corresponding histology.

We investigated the topographical anatomy of the pelvic fasciae and autonomic nerves using macroscopic slices of five decalcified female pelves. The lateral aspect of the supravaginal cervix uteri and superior-most vagina issued abundant thick fiber bundles. These visceral fibrous tissues extended dorsolaterally, joined another fibrous tissue from the rectum (the actual lateral ligament of the rectum) and attached to the parietal fibrous tissues at and around the sciatic foramina (i.e. the sacrospinous ligament, thick fasciae of the coccygeus and piriformis and dorsal end of the covering fascia of the levator ani). The inferior or ventral vagina also issued thick fiber bundles communicating with the levator ani fascia. This connection between the vagina and levator fascia, when stretched, seemed to provide a macroscopic morphology called the arcus tendineus fasciae pelvis. The overall morphology of the visceroparietal fascial bridge exhibited a bilateral wing-like shape. The fascial bridge complex was adjacent but dorso-inferior to the internal iliac vascular sheath and located slightly ventral to the pelvic splanchnic nerve. However, the pelvic plexus and its peripheral branches were embedded in the fascial complex. The hypogastric nerve ran along and beneath the uterosacral peritoneal fold, which did not contain thick fibrous tissue. During surgery, in combination with the superficially located vascular sheath, the morphology of the visceroparietal fascial bridge and associated nerves seemed to be artificially changed and developed into the so-called cardinal, uterosacral, uterovesical and/or rectal lateral ligaments. The classical and original concepts of these pelvic fascial structures may need to be altered to adjust to these surgical observations.

Aged↗
PubMed2003

A new perspective on nerve-sparing radical hysterectomy: nerve topography and over-preservation of the cardinal ligament.

BACKGROUND: Nerve-sparing radical hysterectomy was established by Japanese gynecologists. They identified two parts of the cardinal ligament, namely the vascular part and the neural part, and postulated that the neural part contained the pelvic splanchnic nerves. However, our fresh cadaver studies demonstrated that these nerves ran dorsomedially in contrast to the classical concept. The aim of this study is to further validate this finding in clinical cases. METHODS: We examined the intraoperative biopsy specimens collected from the neural part of the cardinal ligament in four patients with cervical carcinoma who underwent nerve-sparing radical hysterectomy with dissection of the neural part. RESULTS: Careful dissections demonstrated that the pelvic splanchnic nerves arise from the dorsomedial side of the neural part at the bottom of the pararectal space. The neural part was composed of a connective tissue with focal positive staining by S-100 protein. CONCLUSIONS: We propose that complete dissection of the cardinal ligament should be performed during nerve-sparing hysterectomy to increase its radicality.

Broad Ligament↗
PubMed2002

Does the cardinal ligament of the uterus contain a nerve that should be preserved in radical hysterectomy?

The cardinal ligament (CL) of the uterus is present as a specific part of the parametrium when the pararectal and paravesical spaces are developed surgically. According to usual nerve-sparing radical hysterectomy (the Tokyo method), the CL is divided into two parts, the vascular part for dissection and the nerve part that contains the pelvic splanchnic nerve (PSN) as a major target for nerve sparing. In contrast, we hypothesized that the CL and another structure outside of the usual area for surgical dissection, that is, the lateral rectal ligament, are mutually continuous and that the PSN runs through the lateral ligament rather than the CL. In the present study, a combination of routine dissection, fresh cadaver dissection and in situ sectional anatomy revealed that: (i) the CL did not contain the PSN; (ii) a well-defined fascial structure existed in the bottom or dorsal margin of the CL area; and (iii) the pelvic plexus was separated from vascular components of the CL. The present results provide a new perspective for nerve-sparing radical hysterectomy with extensive lateral parametrial dissection of the CL.

Aged↗
PubMed1997

Electron-Transfer Reactions of Aromatic alpha,beta-Epoxy Ketones: Factors That Govern Selective Conversion to beta-Diketones and beta-Hydroxy Ketones.

Photoreaction of trans-1-(4-cyanophenyl)-3-phenyl-2,3-epoxy-1-propanone (trans-4'-cyanochalcone epoxide) with various electron donors was studied. Irradiation of this epoxy ketone with amines produced 1-(4-cyanophenyl)-3-phenyl-1,3-propanedione and 1-(4-cyanophenyl)-3-hydroxy-3-phenyl-1-propanone in various ratios depending on the kinds of amine and solvent used. A reaction mechanism involving an amine cation radical-assisted rearrangement of the epoxy ketone anion radical was proposed to be most consistent with the marked change in the yield of beta-diketone. On the other hand, the timing of proton transfer to the anionic intermediates is considered to be a key factor to yield the beta-hydroxy ketone. Information obtained from the photochemical study was useful to find the reaction conditions for the conversion of several aromatic epoxy ketones to hydroxy ketones by the use of samarium diiodide. Addition of methanol significantly changed the product distribution. Proper choice of water or methanol as a proton source produced hydroxy ketones in moderate to good yields.

Journal Article↗