Differences in platelet calcium regulation between African Americans and Caucasians: implications for the predisposition of African Americans to essential hypertension

OBJECTIVE

To study differences in cytosolic free calcium regulation between African Americans and Caucasians, using platelets as a model for studying cellular physiology.

DESIGN

Platelet calcium regulation in apparently healthy African American and Caucasian males was examined.

METHODS

Using fura-2, calcium influx and cytosolic calcium extrusion were monitored after treatment with thapsigargin, an inhibitor of the Ca-ATPase in the dense tubular membrane system.

RESULTS

Compared with Caucasians, platelets from African Americans demonstrated a higher calcium influx into the cytosol (from the external medium and dense tubular membrane system), as well as enhanced calcium extrusion from the cytosol.

CONCLUSIONS

Such findings indicate that platelets from African Americans have increased intracellular calcium stores or increased cellular calcium turnover, or both. If these racial differences involve other cells, such as vascular smooth muscle cells, they could underlie the predisposition of African Americans to essential hypertension.

Analysis of regional differences of p53 mutation in advanced gastric carcinoma: relation to heterogeneous differentiation and invasiveness

In order to examine the correlation of p53 mutation with heterogeneous histological differentiation and invasiveness of gastric carcinoma, we analyzed 46 areas (three to six per case) that were different histologically and anatomically in 12 advanced gastric carcinomas, shown previously to be positive for p53 mutation, using immunohistochemical, polymerase chain reaction-single strand conformation polymorphism, and direct DNA sequencing analyses. DNA derived from different sites in nine cases had the same pattern of p53 mutation, even in cases manifesting heterogeneous histology within a single tumor. Site difference of the p53 mutation was found in three cases: two showed no mutation in superficial tumor areas but presence of mutation in deep-infiltrating areas. In contrast, one case contained a mutation in the superficial area but not in the deep-infiltrating area. These results suggest that in most cases, tumor cells forming a single advanced gastric carcinoma, even though they may present a heterogeneous histology and deep invasion, seem to be derived from the same cellular clone.

Primary choriocarcinoma of the urinary bladder--a case report

We report a primary choriocarcinoma of the urinary bladder in a 63-year-old man who presented with painless hematuria. He was diagnosed as having an invasive carcinoma and underwent a total cystectomy. The tumor was diffusely hemorrhagic and occupied the dome of the bladder. Histologically, it consisted of cyto-and syncytiotrophoblasts with extensive hemorrhage. No coexisting transitional cell carcinoma component was present. By immunohistochemistry, the tumor expressed beta-hCG and low-molecular weight cytokeratin intensely while it was negative for CEA or EMA. The post-cystectomy serum beta-hCG was 237mlU/ml, and decreased later. The pertinent literature is reviewed and diagnostic criteria are discussed.

Platelet sodium-hydrogen antiport in obese and diabetic black women

In this investigation we correlated platelet Na-H antiport parameters with blood pressure and serum lipids in a sample population of non-insulin-dependent diabetic obese, nondiabetic obese, and nondiabetic nonobese black women. Parameters of the Na-H antiport were examined in aspirin-treated platelets. These parameters were not altered in resting or in thrombin-stimulated platelets of diabetic patients. The activity index of platelet Na-H antiport after thrombin stimulation was positively correlated with the blood pressure (systolic blood pressure, r = 0.5320 and p = 0.0001; diastolic blood pressure, r = 0.5123 and p = 0.0017). Lower high density lipoprotein cholesterol levels were associated with an alkaline shift in the cytosolic pH set point for activation of the Na-H antiport. Highly significant correlations were also observed between the total cholesterol/high density lipoprotein cholesterol ratio and the cytosolic pH set point for activation of the Na-H antiport. These correlations were independent of diabetes or the body mass index. Together, these observations indicate that parameters of platelet Na-H antiport are altered with an increase in blood pressure and a decrease in serum high density lipoprotein cholesterol.

Progressive atypical peripheral neuropathy following nephrectomy in a patient with renal cell carcinoma

Peripheral neuropathy or amyotropic lateral sclerosis can be associated with renal cell carcinoma. We report a 63-year-old male patient with renal cell carcinoma who developed an atypical, progressive neuropathy after nephrectomy.

Cytogenetic analysis of meningiomas

Cytogenetic analysis of 4 cases of meningiomas from 3 male and 1 female patients is reported. One of male patients suffered from neurofibromatosis type 2. Histologically, the meningiomas were meningotheliomatous (1), transitional (2), and psammomatous (1). Chromosomal abnormalities were found in all cases with a karyotype 45,XY,-22, 45,XY,-16, 45,XX,-2, and 45,XY,t (15p;22q), respectively. Monosomy of chromosome 22 was detected only in the patient with neurofibromatosis type 2. These cytogenetic analysis demonstrates that variable clonal karyotype aberrations exist in meningiomas.

[Development of a scale to measure the self concept of cesarean section mothers]

Recently, the rate of cesarean section in Korea has been increasing. The results of several previous studies in foreign countries on the emotional responses of cesarean section mothers showed that they might experience difficulties in the mother-infant interaction due to fatigue, lack of early mother-infant interaction, disappointments, anger, feelings of loss of control, and other factors. Human behavior is said to be determined by one's self concept, and self concept is influenced by both internal and external environmental factors. A scale to measure the self concept of cesarean section mothers was needed in order to identify those who might have difficulties in the mother-infant interactions in future. The purposes of this study were to develop a measuring scale, and to test its reliability and validity. The process of this study was as follows. A structured interview was done with 50 cesarean section and vaginal delivery mothers to find their state of emotional reaction after giving birth to their babies. Based on the results of the interviews, a 50 items Likert scale was developed. The self concept of 268 cesarean section and vaginal delivery mothers who were hospitalized at six hospital in seoul were measured, during the period between Feb. 1 and April 30. Reviewing the discriminating power of each item by means of crosstabulation, ten items were selected for the final scale. The reliability and validity of this ten item scale were tested by Cronbach's alpha and t-test, using spss pc + package. The results of this study and recommendation are as follows. 1. The ten selected items were as follows. I feel pains in my breast. (-) I have a good appetite now. (+) I feel pains in my flank. (-) I feel fine now. (+) My body seems to have returned to its prepregnant state. (+) Thinking of the delivery process, I feel sorry. (-) I want to hold my baby in my arms. (+) I want to keep my own life, even if I became a mother. (-) I want to delegate the care of the baby to my mother/mother in law. (-) I think baby is my alter ege. (+) 2. The reliability of this scale was tested by Cronbach's alpha, and the coefficient of this scale was .8066. 3. The construct validity of this scale was tested by means of known group methods. The value of self concept for cesarean section mother was significantly lower than for vaginal delivery mothers (t = -5.51, df = 266, p = 0.007).(ABSTRACT TRUNCATED AT 400 WORDS)

[A study on the mechanical behaviors of abutment teeth with various coping designs under overdenture]

An overdenture is a complete denture supported by both soft tissue and a few remaining natural teeth. The purpose of this study was to analyze the stress distribution of the teeth and supporting structures when various type of coping under overdenture was applied. The analysis was conducted by using the finite element method and changing the condition such as the direction of the load, the shape of coping on the abutment: The model included overdenture copings, abutment tooth and supporting structures. The results of analysis were as follows: 1. The short dome coping showed well distribution of stress. 2. The dome shaped design produced higher stress distribution than square and inclined plane design. 3. As the height of copings on the abutment was increased, the displacements increased. 4. The magnitude and direction of the abutment displacements were influenced by the direction of load application.

Aneurysmal ("angiomatoid") fibrous histiocytoma in a child

A case of aneurysmal ("angiomatoid") fibrous histiocytoma (AFH) in a 12-year-old girl is presented with its unusual clinicopathologic features. The lesion had the full microscopic characteristics of AFH described in prior reports, but it also had some features that differed from the original description of the disorder, such as the involvement of subcutis, its occurrence in the scalp, and a documented history of minor trauma. The lesion clinically resembled the gross features of hemangioma. The experience in the present case raises the need for considering AFH as one of major differential diagnosis of nodular cutaneous tumors in children that simulate malignancy such as angiomatoid malignant fibrous histiocytoma and Kaposi's sarcoma.

Multiple rhabdomyoma of the heart presenting with a congenital supraventricular tachycardia--report of case with ultrastructural study

A case of congenital rhabdomyoma of the heart in a 5-month-old Korean infant is described. The patient presented with a congenital supraventricular tachyarrhymia that was detected in utero by fetal sonography. The tumor was multiple, but no obvious association with tuberous sclerosis complex was demonstrated. Microscopic examination revealed classic "spider cells" with rich glycogen content. Ultrastructurally, the cells contained numerous leptofibrils, clumped Z band material, and desmosome-like cell junctions. The case is a second documented case of cardiac rhabdomyoma in this country, and its presentation as an etiological factor of supraventricular tachycardia is a very unusual manifestation.

Intravesical instillation therapy with adriamycin for bladder cancer in the Korean study group

Eighteen cases of bladder cancer were treated with intravesical instillation therapy with 60 mg Adriamycin daily. Overall, the treatment was markedly effective in two cases, effective in nine cases, and ineffective in seven cases. Bladder irritation was noted in four cases. Postinstillation therapy was required in most cases.

Chlorpropamide-induced haemolytic anaemia

A newly diagnosed diabetic patient, recently started on chlorpropamide, required emergency admission because of sudden onset of weakness and syncope. In vitro testing confirmed the diagnosis of chlorpropamide induced haemolysis, and withdrawal of the drug resulted in clinical recovery.

Performance of Korean medical and nursing students on the East-West Questionnaire

Korean medical and nursing students were more Eastern in their belief systems than American college students in introductory psychology on the East-West Questionnaire. The Americans and Koreans differed most with regard to beliefs about spiritual matters, the former being Western in orientation and the latter, Eastern. Korean Buddhists also scored more Eastern than Korean Christians or those with no formal religion.

Paraplegia following trauma in a patient with kyphosis

The reported incidence of paraplegia following acute spinal trauma in patients with kyphosis is very low. One such case is presented here and discussed. Although deterioration of spinal cord function in patients with kyphosis who have not sustained trauma is treated by surgical decompression and stabilization of the spine, a more conservative approach may be beneficial in those patients with a history of trauma. Thus, the treatment appears to follow that now recommended for acute spinal injuries in patients with a premorbidly normal spine.