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Biomedical subjects

K Seki

Publications and source records attributed to K Seki.

At least 217 records · Page 12Linked to original sources

[A case of an intrapulmonary lymph node indistinguishable from carcinoma of the lung by CT].

A 64-year-old female was referred to our hospital for further examination of a coin lesion, 8 mm in diameter, superimposed on the right ninth posterior rib. CT revealed a nodule, close to the minor fissure, with spiculation, which seemed to be connected with the pulmonary vein. Since the bronchofiberscopic examination revealed no histological diagnosis, the exploratory thoracotomy was performed. The nodule was found to be a 10 x 7 x 5 mm black mass located subpleural at the minor fissure. Histologically, it was recognized as a lymph node with anthracosis and silicotic nodules.

Diagnosis, Differential↗

[Recurrent dislocation of the elbow].

A case of a recurrent dislocation of the elbow joint in a 13-year-old female is described. The patient sustained a medial epicondylar fracture of the humerus and consulted us four months later. There was no deformity but marked lateral instability of the elbow was recognized. It could be fully flexed and hyperextended ca 20 degrees. The elbow joint could be easily dislocated by pronation of the hyperextended elbow. Roentgenogram demonstrated an apparent non-union of the medial epicondylar fracture. The fragment was repositioned so that the medial collateral ligament became taut. There was no recurrence of the dislocation ten months postoperatively.

Adolescent↗

Biochemical and genetic heterogeneity of staphylococcal protein A.

We investigated the biochemical and genetic heterogeneity of protein A from Staphylococcus aureus. SpA genes (spas) of various strains were heterogeneous when detected as DraI and EcoRV fragments of chromosomal DNA. Polymerase chain reaction using primers to detect DNA encoding the IgG-binding domains in spa revealed that they numbered between 2 and 5. Protein A from several S. aureus strains showed two types of reactivities to immunoglobulins in normal canine serum according to the number of active domains.

Base Sequence↗

Long-term results of primary closure for ventricular septal defects in the first year of life.

The long-term results of primary closure for large ventricular septal defects (VSDs) in infants under 1 year of age with severe symptoms were studied over a period of more than 10 years. Between January, 1971 and March, 1982, 49 infants underwent primary closure of a VSD through a right ventriculotomy using complete cardiopulmonary bypass with mild hypothermia. There were four hospital deaths but no late deaths. Two of four infants with residual shunts had a left ventricular-right atrial shunt which necessitated reoperation. Surgical heart block occurred in two infants who recovered sinus rhythm in the late period. The cardiothoracic ratio decreased from 60.5% preoperatively to 50.6% in the late postoperative period. Examination by cardiac catheterization revealed that the pulmonary-to-systemic pressure ratio (Pp/Ps) of 23 patients with a Pp/Ps of over 0.75 fell from 0.89 +/- 0.09 preoperatively to 0.42 +/- 0.12 by 1 month postoperatively, then to 0.27 +/- 0.05 in the late postoperative period. The latest values for the cardiac index and left ventricular ejection fraction were 3.4 l/min per m2 and 64.4%, respectively. More than 10 years after their operation, all the survivors were growing normally and maintaining a good quality of life, which supports our recommendation that primary repair should be performed in the first year of life for infants with large VSDs.

Bundle-Branch Block↗

Mechanism of pain and cytoskeletal properties in angioleiomyomas: an immunohistochemical study.

Angioleiomyoma is a solitary subcutaneous tumor characterized by pain in about half of patients with this tumor, and the pathogenesis of this pain has been a cause of much debate. To clarify the mechanism of pain and cytoskeletal property of tumor cells, 50 angioleiomyomas were studied clinicopathologically and immunohistochemically. The tumors occurred preferentially on the extremities, particularly the lower leg (46%), and the female to male ratio was 1.9:1. They were classified into three histological subtypes: (i) solid (30 cases); (ii) venous (15 cases); and (iii) cavernous (five cases). The pain and/or tenderness were present in 26 out of 49 patients (52%), in which small nerve fibers immunoreactive for S-100 protein and PGP9.5 were identified within the capsule of 20 tumors (77%) and the tumor stroma of 18 (69%), irrespective of the histological subtypes. In 24 patients where the pain was absent or unknown, nerves were observed within the capsule of 19 tumors (79%) and tumor parenchyma of 10 (42%). Many cells in all 50 tumors were positive for alpha-smooth muscle actin, and a relatively large number of cells in many tumors were positive for vimentin, desmin and collagen type IV. Also, cytokeratin (CAM5.2) reactivity was scattered in a few cells of four tumors. From these findings, the peculiar pain of angioleiomyomas could be mediated by the nerve fibers especially located within the tumor parenchyma. Although the expression of intermediate filaments in angioleiomyomas was heterogeneous, the overall cytoskeletal features were of smooth muscle cell differentiation.

Adolescent↗

Influence of left ventricular regional nonuniformity on afterload-dependent relaxation in intact dogs.

The time course of systolic loading conditions is considered an important factor in affecting left ventricular (LV) relaxation. However, the exact underlying mechanisms remain controversial. The goal of this study was to evaluate the role of the change in loading sequence on LV regional wall motion and LV relaxation. Early and late systolic loading were produced by constricting the ascending aorta and the descending aorta, respectively, in seven anesthetized dogs. In two pairs of cardiac beats with a comparable peak LV pressure during the mild and moderate constrictions of the ascending or descending aorta, we measured LV time constant (T) of LV pressure decay and determined regional nonuniformity in basal and apical segmental motion during the isovolumic relaxation period (by Lew's method). Constriction of the descending aorta led to a significant delay of the timing of peak LV pressure, associated with an increase in T, end-systolic pressure, and the regional nonuniformity between the two segments. T was correlated well with the amount of the nonuniformity, suggesting that LV regional nonuniformity between basal and apical regions might be involved in the complex mechanism of afterload-dependent relaxation.

Animals↗

Role of vagal afferents in hypotension induced by venous air embolism.

To evaluate the role of the autonomic nervous system in the development of hypotension during air embolism, we studied the effects of an intravenous bolus injection of air (0.5 ml/kg) on mean blood pressure (MBP), central venous pressure (CVP), and renal nerve activity (RNA) in urethan-anesthetized rabbits of three groups: animals with an intact neuraxis (intact group; n = 5), cervical-vagotomized animals (vagotomy group; n = 5), and sinoaortic-denervated animals (SAD group; n = 5). In the intact group, despite a significant decrease in MBP at 10 s after air injection, RNA did not increase from the preinjection level. This response of RNA was associated with a significant increase in CVP and lasted for 20 s after the injection. Vagotomized animals, however, exhibited a significant augmentation in RNA in response to a drop in MBP at 10 s after the injection. In the SAD group, profound declines in both MBP and RNA were observed at 10 s after the injection of air. Animals in these two groups showed remarkable increases in CVP. At 5 min after the air administration, MBP in the vagotomy group was significantly higher than that in the intact group. All animals in the SAD group died within 5 min of the injection. These results indicate that during hypotension induced by air injection, sympathetic activation through arterial baroreceptors may be depressed by vagal afferents emanating from cardiopulmonary receptors; the results also suggest that the arterial baroreceptor nerves may be required to overcome the lethal events that should occur during venous air embolism.

Animals↗

A novel biological aspect of ovarian oxytocin: oxytocin gene expression in cumulus/luteal cells and the effect of oxytocin on embryogenesis in fertilized oocytes.

Recently, several reports have demonstrated the presence of oxytocin (OT) in the corpus luteum of mammalian species. However, the biological role of ovarian OT remains obscure. This study was performed to examine OT gene expression in cumulus cells of mice and humans, and in human corpus luteum, and the role of OT in early embryogenesis. OT gene and OT mRNA were analyzed by reverse transcription-polymerase chain reaction, with single-strand-conformation polymorphism and heteroduplex procedures. OT-treated in-vitro-fertilized mouse oocytes were cultured and the rate of blastocyst development estimated. An immunohistochemical study was also carried out to detect OT on the surface of the mouse oocytes.

Animals↗

Parathyroid hormone-related protein during pregnancy and the perinatal period.

To evaluate whether parathyroid hormone-related protein (PTHrP) plays any role in calcium metabolism during pregnancy and the perinatal period, we measured parathyroid hormone (PTH), immunoreactive PTHrP and calcium in maternal serum of women during pregnancy and puerperium, and in maternal and cord serum at delivery. Serum PTH levels in pregnant women were lower than those in nonpregnant women (p < 0.01). However, serum PTHrP levels were similar in the two groups of women. Cord serum total and ionic calcium levels were higher, and cord serum PTH levels were lower compared to maternal values (p < 0.01). Cord serum PTHrP levels were higher than maternal values, and umbilical arterial levels were higher than umbilical venous levels (p < 0.01). Higher levels of PTHrP in umbilical arterial blood than in umbilical venous blood suggest that the main source of cord blood PTHrP may be the fetus. PTHrP is reported to stimulate placental calcium transfer from mother to fetus in animals. The elevated cord blood PTHrP level in association with the decreased PTH level suggests that stimulation of placental calcium transfer by PTHrP may also be operative in humans.

Calcium↗

Pathology of olfactory mucosa in patients with Alzheimer's disease.

Characteristic changes that appear in the biopsied olfactory mucosa of patients with Alzheimer's disease (AD) were examined with immunohistochemical staining. Specimens were obtained from patients with clinical diagnoses of AD. Patients with vascular dementia and age-matched patients without dementia were used for controls. In most AD cases, neurofibrillary tangle-like abnormal tau protein (Tau) immunoreactivity was seen in the dendrites and perikarya of the olfactory receptor cells and in the nerve bundles. A senile plaque-like extracellular mass was found in the olfactory epithelium, and it reacted strongly to an anti-Tau antiserum and weakly to an anti-amyloid-beta protein antiserum. Ubiquitin (Ubq) immunoreactivity was also observed in the dendrites. Tau immunoreactivity of the perikarya and extracellular mass, and Ubq immunoreactivity were especially characteristic of the olfactory mucosa of AD patients. From these results, it is clear that the same pathologic changes in the brain are also present in the olfactory mucosa of patients with AD. Not only disruption of the central olfactory pathway, but also an olfactory disturbance of AD patients is caused by peripheral changes. Furthermore, an olfactory mucosal biopsy could be a useful method for a definitive diagnosis of AD.

Aged↗

Cord blood levels of calcium-regulating hormones and osteocalcin in premature infants.

We measured cord blood levels of calcium-regulating hormones and osteocalcin in 34 premature infants of various gestational ages. 1,25(OH)2D levels were low in mid-gestation and increased with advancing gestation. Parathyroid hormone levels were low, and calcitonin levels were high in mid-gestation. Both of them declined with advancing gestation. Osteocalcin levels were high in mid-gestation. They increased from 22 weeks through 27 weeks of gestational age, and decreased thereafter. Circulating osteocalcin is considered as a clinical marker of bone turnover. However, cord blood osteocalcin decreased between 27 and 36 weeks of gestation during which period calcium accumulation by the fetus increases. Therefore, cord blood osteocalcin does not appear to reflect fetal bone formation.

Calcitonin↗

Relationship between heart rate and oxygen uptake during submaximal arm cranking in paraplegics and quadriplegics.

The purpose of this study was to clarify the effect of the level of spinal cord injury (SCI) and of daily exercise on the relationship between heart rate (HR) and oxygen uptake (VO2) in persons with SCI (PSCI) during an arm cranking exercise. Eighteen PSCI were divided into three groups according to the level of SCI; 4 quadriplegics (C6-C8), 7 high- level paraplegics (T3-T8), and 7 low-level paraplegics (T10-L2). In the relationship between HR and VO2, the higher the level of SCI, the smaller the slope of regression line, that means the HR at a given VO2 become larger as level of SCI was higher. Significant differences were found among these regression lines (P < 0.01). In addition, the regression lines between HR and VO2 in active persons tended to shift toward upper in comparison with those in inactive persons. The present investigation clearly shows that the HR-VO2 relationship in PSCI is remarkably influenced by the level SCI and physical training.

Adult↗