Search PubMed⌕ Search

Biomedical subjects

K Kamoi

Publications and source records attributed to K Kamoi.

At least 55 records · Page 3Linked to original sources
PubMed1995

Hyponatremia and osmoregulation of vasopressin secretion in patients with intracranial bleeding.

To clarify the cause and pathophysiology of hyponatremia after intracranial bleeding, we analyzed the possible causative factors, and examined the response of vasopressin (AVP) secretion to osmotic stimulus in six patients. Despite hyponatremia, urinary sodium excretion persisted, with urinary osmolality exceeding plasma osmolality. Serum levels of urea nitrogen, creatinine, and uric acid were not elevated in any of them. PRA was normal or subnormal in four patients, and all had normal adrenocortical and thyroid functions. Although these laboratory findings may support the diagnosis of the syndrome of inappropriate antidiuretic hormone secretion, the cause of hyponatremia in our patients was attributed to excessive renal excretion of sodium, because water load performed in an euvolemic state showed no impairment in diuresis, and replenishment of sodium without water restriction improved hyponatremia as well as clinical conditions. Plasma AVP levels relative to plasma osmolality in these patients were constantly elevated. When challenged by an osmotic stimulus, AVP secretion increased with increasing plasma osmolality in one patient, but no consistent pattern of AVP secretion was observed in others. The potentiating effect of hypovolemia on osmotic secretion of AVP was not demonstrated in any of the patients. These results show that hyponatremia after intracranial bleeding with clinical features almost indistinguishable from those of syndrome of inappropriate antidiuretic hormone secretion may result from an impaired renal sodium-conserving mechanism of unknown cause. Persistent AVP secretion without an alteration in the sensitivity of the osmostat in this pathological state may be due to an incomplete suppression by plasma hypotonicity per se of the baroreceptor-mediated stimulation of AVP release.

Aged↗
PubMed1994

Endothelin-1 and big endothelin-1 in NIDDM patients with and without microangiopathy.

To examine a possible role for endothelin-1 in the pathophysiology of diabetic microangiopathy, we measured plasma levels of endothelin-1 and big endothelin-1, a precursor peptide of endothelin-1, in 33 untreated patients with non-insulin-dependent diabetes mellitus. There was no significant difference among the mean plasma endothelin-1 concentrations in 18 patients with microangiopathy, in 15 patients without microangiopathy and in 33 age-matched normal subjects. In contrast, the mean plasma big endothelin-1 concentration in patients with microangiopathy was significantly higher than in those without microangiopathy or in normal subjects. As a consequence, the mean big endothelin-1 to endothelin-1 ratio in patients with microangiopathy was significantly higher than in the other two groups. There was no significant correlation between plasma levels of endothelin-1 or big endothelin-1 and fasting blood glucose, HbA1c, mean blood pressure, or period of duration of diabetes mellitus in the patient groups. The results indicate that elevation of plasma big endothelin-1 levels with diminished conversion of big endothelin-1 to endothelin-1 is associated with diabetic microangiopathy, which may be the effect rather than the cause of endothelial dysfunction.

Adult↗
PubMed1994

Effect of an angiotensin II receptor antagonist, TCV-116, on rat carotid artery neointimal formation after balloon injury.

Arterial injury by a balloon catheter produces marked smooth muscle cell proliferation and the participation of angiotensin II in this response has been suggested. In this study, we examined the effect of a novel angiotensin II type I receptor antagonist, TCV-116, on neointimal formation after rat carotid artery balloon injury. Oral administration of TCV-116 at doses of 1, 5 or 10 mg/kg/day significantly reduced the cross-sectional intimal area by 30%, 46% and 54%, respectively, and reduced the ratio of the intimal to medial cross-sectional areas by 23%, 41% and 50%. An angiotensin-converting enzyme inhibitor, lisinopril, had an effect similar to that of TCV-116. The effect of both drugs was significantly correlated with the reduction of both blood pressure and cardiac hypertrophy. We conclude that TCV-116 can prevent neointimal formation after balloon injury as well as reducing blood pressure and preventing cardiac hypertrophy.

Angiotensin Receptor Antagonists↗
PubMed1993

Effect of LHRH analog on the seminal vesicles evaluated by transrectal sonography.

The maximum horizontal area (MHA) of the seminal vesicles was measured in 20 prostatic cancer patients by means of transrectal sonography (TRS) after LHRH analog treatment. MHA of the seminal vesicles changed in parallel to the serum testosterone (T) level and decreased by 11-62%, compared with the baseline after LHRH analog treatment for 4 months. Two different patterns were observed for the change of MHA. In 9 cases, MHA of the seminal vesicles increased transiently and then decreased gradually, while in the other 11 cases, MHA decreased continuously from the beginning with no significant increase. Thus, the direct and dynamic response of the seminal vesicles to the change of serum T level was clarified.

Aged↗
PubMed1993

Seminal vesicle parameters at 10-year intervals measured by transrectal ultrasonography.

The volume, maximum horizontal area, maximum length, maximum width and depth of the seminal vesicles were measured by transrectal ultrasonography in 76 subjects without seminal vesicle disorders, divided into 7 groups at 10-year intervals. The average of each parameter in each group was presented. The volume and maximum horizontal area began to decrease after the age of 60 years. No statistically significant difference among subject ages was observed for the other 3 parameters. A correlation was observed between the volume and maximum horizontal area of the seminal vesicles. Our study confirmed that maximum horizontal area of the seminal vesicles may be substituted for the volume.

Adult↗
PubMed1993

Hyponatremia and osmoregulation of thirst and vasopressin secretion in patients with adrenal insufficiency.

To clarify the mechanism underlying abnormal vasopressin (AVP) secretion in glucocorticoid deficiency, we examined the response of AVP secretion to osmotic stimulus produced by 5% saline infusion and analyzed the possible causative factors in seven patients with hypoosmolal hyponatremia resulting from adrenal insufficiency. In all patients, urinary sodium excretion persisted with urine osmolality exceeding plasma osmolality, and plasma AVP levels relative to plasma osmolality were elevated. Blood urea nitrogen, plasma creatinine, and PRA ranged from low to normal. All patients had nausea or vomiting, three had hypotension, and two had hypoglycemia; however, the primary cause of increased AVP secretion was attributed to none of these stimuli. After 5% saline infusion, patterns of changes in plasma AVP levels in individual patients were variable: levels decreased with increasing plasma osmolality in two patients and remained unchanged in the other five patients. Despite hyponatremia and absence of hypovolemia, thirst was present in the five patients, who responded normally to questions. This abnormality in AVP secretion and thirst was corrected after glucocorticoid replacement with normalization of plasma sodium concentrations and osmolality. Thus, glucocorticoid deficiency in man results in a clinical picture almost indistinguishable from that of the syndrome of inappropriate secretion of antidiuretic hormone. Persistent AVP secretion in this pathological state is due to a loss of hypotonic suppression of the osmostat for AVP release, which may be occasioned primarily by glucocorticoid deficiency per se and aggravated secondarily by multiple nonosmotic stimuli including nausea, hypotension, and hypoglycemia.

Adrenal Insufficiency↗
PubMed1993

Plasma endothelin-1 and big endothelin-1 levels in women with pre-eclampsia.

To examine a possible role for endothelin-1 (ET-1) and conversion of big ET-1 to ET-1 in the pathophysiology of pre-eclampsia, we measured plasma levels of ET-1 and big ET-1 in 16 women with pre-eclampsia in the third trimester and compared them with those in 11 age-matched normotensive pregnant women and in 10 age-matched pregnant women with chronic hypertension in the third trimester. The plasma concentrations of ET-1 and big ET-1 in the normotensive pregnant women were significantly lower than those in 16 non-pregnant women with a higher molar ratio of big ET-1 to ET-1 in the former group. The plasma concentrations of ET-1 and big ET-1 in the women with pre-eclampsia, on the other hand, were significantly higher than those in the normotensive pregnant women and the molar ratio of big ET-1 to ET-1 in the former group was less than that in the latter group. In sharp contrast, plasma ET-1 and big ET-1 levels in the pregnant women with chronic hypertension were not significantly different from those in the normotensive pregnant women. When examined after delivery, elevated plasma ET-1 and big ET-1 in the women with pre-eclampsia declined, with restoration of normal blood pressure, to the levels in the normotensive women after parturition. There were no significant differences of the levels of ET-1 and big ET-1 in umbilical venous plasma and simultaneously drawn maternal plasma at cesarean section between normotensive pregnant women and women with pre-eclampsia, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Epithelial cell kinetics with atelocollagen membranes: a study in rats.

A recent development in guided tissue regeneration procedures is the use of resorbable membranes, which eliminate the need for subsequent surgical removal. In this study we performed flap surgery in rats with (experimental) or without (control) implantation of one of the newer materials, atelocollagen. We observed the gingival epithelial cell kinetics using 3H-thymidine and examined the extent of gingival epithelium migration. Histological observations at day 1 on the experimental side demonstrated regenerated epithelium apposed to the collagen membrane with an intervening layer of necrotic tissues and/or fibrinous exudate. There was no observable proliferation of regenerated epithelium toward the root apex. On day 14, the regenerated epithelium migrated apically along the treated root surface in the control group. By contrast, on day 14 in the experimental group, the regenerated epithelium contacted the root surface at the cemento-enamel junction (CEJ). Apical to the CEJ, there was new cementum formation with inserting connective tissue fibers. Autoradiographs from day 1 experimental sides demonstrated labeled cells in the basal cell layers from oral, crevicular, and junctional epithelium. From day 1 to day 5, labeling indices of oral epithelium and regenerating crevicular epithelium on experimental sides were lower than on control sides. These histological and autoradiographic findings suggest that atelocollagen membrane inhibits apical migration of regenerating epithelium and accelerates connective tissue reattachment in part by inhibiting the mitotic function of basal epithelial cells in early stages of wound healing.

Animals↗
PubMed1993

[Ofloxacin concentration in prostatic tissue].

The concentration of ofloxacin in prostatic tissue and serum was determined in order to evaluate the permeability of ofloxacin into prostatic tissue in patients with benign prostatic hypertrophy. Ofloxacin was administered orally at a dose of 200 mg several hours before subcapsular prostatectomy. The determination was performed in the surgically removed adenoma and in the serum taken one hour before and at the removal of the adenoma. The peak level in the prostatic tissue was 1.46 microgram/g at 4.5 hour after the administration. The ratio of prostatic tissue level to the serum level was 1.00. In conclusion, ofloxacin was thought to be very useful for the treatment of acute and chronic prostatitis.

Aged↗
PubMed1993

Bactericidal effects of povidone-iodine solution to oral pathogenic bacteria in vitro.

Seven species of periodontal pathogenic bacteria (Bacteroides, gingivalis, Bacteroides intermedius, Bacteroides melaninogenicus, Fusobacterium nucleatum, Actinobacillus actinomycetemcomitans, Capnocytophaga spp., Eikenella corrodens) and two control species (Streptococcus intermedius, Pseudomonas aeruginosa) were selected in order to study the bactericidal effects of 10% povidone-iodine (PVP-I) aqueous solution in vitro. The PVP-I solution was diluted to 10, 20, 50, 100, 200, 400, 800, 1600, 3200, 6400 and 12800 x and contact times were 15, 30 and 60 seconds. The strongest bactericidal effects on the seven periodontal pathogenic bacteria and two control bacteria were seen at a dilution of 400 x and a contact time of 15 seconds. Based on these findings, we advocate a 0.25% solution of 10% aqueous PVP-I for oral mucosa and periodontal pocket irrigation.

Aggregatibacter actinomycetemcomitans↗
PubMed1992

Increase of serum somatomedin C in hyperthyroid patients with pregnancy.

In thyrotoxic women with pregnancy, serum somatomedin C (SmC) concentration was markedly elevated (mean +/- SD 13.57 +/- 4.66 U/ml) compared to thyrotoxic women without pregnancy (1.24 +/- 1.09 U/ml), non-pregnant euthyroid women previously treated for hyperthyroidism (0.87 +/- 0.30 U/ml), normal subjects with pregnancy (6.08 +/- 3.36 U/ml) and pregnant euthyroid women previously treated for hyperthyroidism (5.98 +/- 1.52 U/ml). Since SmC/growth hormone ratio was significantly more in thyrotoxic pregnant women than in normal pregnant women and euthyroid pregnant women previously treated for hyperthyroidism, and since human placental lactogen (HPL), human chorionic gonadotropin (HCG) and prolactin (PRL) do not crossreact with SmC antibody, it is suggested that excess thyroid hormone during pregnancy results in excessive hepatic somatomedin C production.

Adult↗
PubMed1991

Thirst and plasma levels of vasopressin, angiotensin II and atrial natriuretic peptide in patients with non-insulin-dependent diabetes mellitus.

To clarify a possible mechanism whereby the perception of thirst may be associated with diabetes mellitus, we measured plasma levels of vasopressin (AVP), angiotensin II (ANG II), atrial natriuretic peptide (ANP) and plasma renin activity (PRA) in non-insulin-dependent (NIDDM) diabetic patients with or without thirst. Thirteen male NIDDM patients complaining of thirst had a significantly high blood hematocrit, plasma urea nitrogen and creatinine concentrations and plasma osmolality, indicating a reduction in plasma volume. In addition, the patients had a significantly high mean plasma concentrations of AVP (3.20 +/- 1.27 pmol/l) ANG II (33.8 +/- 31.4 pmol/l) and PRA, but a low mean plasma ANP concentration (8.9 +/- 4.5 pmol/l). After treatment with diet and/or sulfonylurea, plasma levels of AVP, ANG II and PRA decreased with a concomitant increase in plasma volume and disappearance of thirst. In contrast, 13 NIDDM patients (9 females and 4 males) without thirst had normal plasma urea nitrogen and creatinine concentrations, and the hematocrit did not change significantly after treatment. Plasma AVP (0.95 +/- 0.34 pmol/l), ANG II (14.7 +/- 8.8 pmol/l) and ANP (10.7 +/- 4.9 pmol/l) concentrations, and PRA were normal in this group of patients. There was no significant difference between the two groups of patients, however, in fasting glucose concentration and HbA1c. We conclude from these results that a reduction in plasma volume may be the major factor responsible for the induction of thirst sensation and for increased AVP secretion in NIDDM patients. The mechanism underlying a reduction in plasma volume remains unclear.

Adult↗
PubMed1991

Anti-thyroid antibodies in patients with hyperprolactinemia.

To clarify the possible role of prolactin in the regulation of immune responses in man, we measured circulating anti-thyroid antibodies in 172 normal subjects, 84 patients with prolactinoma and 63 patients with acromegaly with normal thyroid and adrenocortical functions. Frequencies of positive thyroidal microsome and thyroglobulin antibodies were significantly (p < 0.05 and p < 0.01, respectively) higher in women with prolactinoma (20.6% and 20.6%) than in normal women (7.5% and 4.7%). Men with prolactinoma had a significantly (p < 0.05) higher frequency of positive thyroglobulin antibody (18.8%) than normal men (1.5%). When the subjects were divided by decade, women with prolactinoma in the 4th decade had significantly (p < 0.05) higher frequencies of positive thyroidal microsome and thyroglobulin antibodies (30.8% and 30.8%) than normal women of corresponding age (3.7% and 3.7%). In contrast, there was no significant difference in the frequencies of positive anti-thyroid antibodies in patients with acromegaly and in normal subjects. Analysis of the peripheral lymphocyte population revealed that patients with prolactinoma had a higher percentage of B cells than normal subjects, while there was no significant difference in the percentages of total T lymphocytes or in the helper and suppressor T cell ratios in the two groups of subjects. These results suggest that prolactin regulates humoral immune responses in man directly by stimulating B lymphocytes or indirectly by inhibiting suppressor T lymphocyte activity.

Acromegaly↗
PubMed1990

Atrial natriuretic peptide in patients with the syndrome of inappropriate antidiuretic hormone secretion and with diabetes insipidus.

To examine a possible role for atrial natriuretic peptide (ANP) in water and sodium metabolism disturbances associated with abnormal vasopressin (AVP) secretion, we measured plasma ANP concentrations in 15 patients with the syndrome of inappropriate antidiuretic hormone secretion (SIADH) and in 17 patients with central diabetes insipidus (DI). The mean plasma ANP concentration (30.2 +/- 10.4 pmol/L) in SIADH patients who had hyponatremia, plasma hypoosmolality, hyperosmolar urinary compared to plasma sodium levels, and increased plasma AVP levels relative to plasma osmolality was significantly higher than that in normal subjects (12.6 +/- 4.9 pmol/L), although there was a considerable individual variation in plasma ANP ranging from normal to clearly elevated levels (15.1-47.0 pmol/L). When hyponatremia was corrected by water restriction or demeclocycline administration, plasma ANP levels decreased significantly and fell into the normal range (12.5 +/- 4.3 pmol/L). DI patients who complained of polyuria and polydipsia and had hypoosmolar urine, normal or elevated plasma sodium concentrations, and decreased plasma AVP levels relative to plasma osmolality, on the other hand, had a significantly lower mean plasma ANP level (7.6 +/- 2.9 pmol/L) than normal subjects. There was, again, a considerable overlap between plasma ANP levels in individual DI patients (4.2-13.9 pmol/L) and those in normal subjects. Treatment with 1-desamino-8-D-arginine vasopressin resulted in a significant increase in the mean plasma ANP level (18.6 +/- 8.0 pmol/L). There were no significant correlations between plasma ANP and AVP levels in either group of patients. The results indicate that ANP secretion is modulated by changes in plasma volume consequent to abnormal AVP secretion, which may have a pathophysiological significance in maintaining volume homeostasis.

Adolescent↗
PubMed1990

Glomerular filtration response to acute loading with protein from different sources in healthy volunteers and diabetic patients.

To evaluate the effects of acute protein loading on the glomerular filtration rate, albumin excretion rate and concentration of plasma amino acids, ten healthy volunteers and six type 2 diabetic patients with normoalbuminuria were studied before and after eating 0.7 g/kg body weight of tuna fish, boiled egg white, cheese or tofu (bean curd) on separate days. Furthermore, to study the possible role of glucagon, growth hormone, atrial natriuretic peptide and kallikrein in the responses of glomerular filtration rate to protein, these substances were measured before and after ingestion of tuna fish or egg white in six healthy volunteers. In healthy subjects, glomerular filtration rate increased significantly (p less than 0.01) from 98.1 +/- 4.2 ml/min during the baseline period to 129.9 +/- 6.6 ml/min after ingestion of tuna fish. No significant differences were seen between glomerular filtration rate before and after ingestion of egg white, cheese or bean curd. No significant differences were observed between the baseline albumin excretion rate and that after loading with any of the four kinds of protein. Plasma concentrations of alanine, glycine and arginine (amino acids known to induce glomerular hyperfiltration) increased to a greater degree after ingestion of tuna fish than after administration of the other meals. Diabetic subjects and healthy volunteers had similar responses. Plasma glucagon and growth hormone concentrations increased after ingestion of the tuna fish meal or egg white. Plasma atrial natriuretic peptide concentration and urinary kallikrein excretion were unaffected by ingestion of these two kinds of protein. These findings suggest that responses of glomerular filtration rate to acute protein loading may differ depending on the protein ingested, and that these responses may not be directly induced by glucagon, growth hormone, atrial natriuretic peptide or kallikrein.

Adult↗