Diadenosine 5',5'''-P1,P4-tetraphosphate, a potential antithrombotic agent

Diadenosine tetraphosphate (AP4A), a competitive inhibitor of ADP-induced platelet aggregation, was tested as an antithrombotic agent in a rabbit intracarotid thrombosis model previously shown to be sensitive to antiplatelet agents. Eighty-four percent of control rabbits formed clots. The infusion of AP4A at a dose of 50 mg/kg over 2 hours reduced the incidence of thrombosis to 56% (p less than 0.05). Blood AP4A increased 125-fold at the end of infusion, but was completely cleared within 10 minutes. Plasma ATP showed bimodal early and late increases. Platelets recovered from AP4A-treated rabbits exhibited a pattern of reduced reactivity to ADP, but not to collagen, similar to platelets exposed to AP4A in vitro. This study shows that AP4A may be a potentially useful antithrombotic agent.

A case of leukemia-associated arthritis--identification of leukemic cells in synovial fluid by light microscopy

One case of arthritis complicating leukemia is described in which leukemic cells were identified in synovial fluid by light microscopy. Although arthritis is a well-known manifestation of leukemia with an incidence of 13.5%, the pathogenesis often is unclear, and the direct demonstration of leukemic cells in synovial fluid has been very uncommon. A 16 year-old male patient was admitted due to left elbow joint pain and swelling. Synovial fluid examination revealed blast cells and this finding has directed to a final diagnosis of acute lymphoblastic leukemia.

Intracranial granulocytic sarcoma (chloroma) in a nonleukemic patient

Chloroma is a granulocytic sarcoma with it's characteristic greenish color. Recently there is an increased number of cases that are apparently aleukemic when the tumor mass is first presented. Recently we experienced a case of granulocytic sarcoma with characteristic green color (chloroma), which showed no evidence of leukemia in the bone marrow and peripheral blood. This patient presented headache, and was diagnosed brain tumor on computed tomography. A left parietal cranietomy was done to remove a large central dome-like mass, 8 cm, involving the dura with a slightly dusky greenish solid appearance. Compact nests of moderately mature granulocytes and immature cells comprised the tumor. Histochemical and electron microscopic studies confirmed these tumor cells as myeloid cells in varying stages of maturation. Several days after the operation, left cervical lymph nodes became palpated, and the biopsied lymph nodes revealed same neoplastic cells seen in the skull. However, bone marrow aspiration, biopsy and peripheral blood smears did not show any evidence of leukemia.

Effectiveness of oral iron chelators assayed in the rat

A 4-hour in vivo test for iron chelator activity in the rat is described. The amount of radioiron in the gut and urine that results from chelator-induced excretion of previously injected radioiron labelled ferritin is measured. Hepatocyte localization and desferrioxamine-induced radioiron mobilization from in vitro tagged homologous ferritin is shown to be similar to that from in vivo tagged ferritin. Non-homologous ferritin preparations labelled in vitro proved unsatisfactory. Radioiron mobilization by chelator occurred regardless of the iron status of the animal. Employing this measurement, the effectiveness of three iron chelators, pyridoxal isonicotinoyl hydrazone, the dimethyl ester of ethylene diamine-N, N'-dis (3-hydroxyphenyl acetic acid), and the dimethyl ester N, N'-di (3-hydroxybenzyl) ethylene-1, ethylene-1, 2-diamine-N, N'-diacetic acid, given orally was determined. All three chelators, when given in comparable dosage, induced iron excretion similar in amount to that observed with parenteral desferrioxamine. In addition, pyridoxal isonicotinoyl hydrazone administered in the diet over a period of 4 weeks was shown to reduce hepatic and splenic iron of normal animals by about one third, providing further validation of this method of evaluating chelator effectiveness.

Multiple myeloma in Korea--clinical analysis and treatment results in 61 cases

A clinical analysis was made of 61 cases of multiple myeloma diagnosed between January 1976 and June 1984 at Seoul National University Hospital using the criteria of the Southwest Oncology Group.

The following observations were made. 1) The major clinical problems at Initial presentation were bone pain(52%), anemia(20 %), renal impairment(11%), and infection(10%). 2) Clinical stages at presentation were stage I, 11%; stage II, 8%; and stage III, 81% of patients. Three(5%) of the patients in stage II and 18(31%) in stage III showed renal impairment with a serum creatinine ≥2.0 mg/dl. 3) Combination chemotherapy produced a response rate of 29% with melphalan and prednisone, and 40% with M2 protocol(among 14 and 20 evaluable patients respectively). Both regimens showed statistically significant survival difference between responders and non-responders(p <0.01). 4) The median survival of all patients was 13 months. 5)Age, calcium level, creatinine level, and performance status were important prognostic factors on survival.

Taurine transport in chronically stimulated fast- and slow-twitch muscles of the rat

Indirect stimulation via the sciatic nerve, 10 or 100 Hz stimulus trains of 1 sec duration, applied every 3 sec, 8 hr/day for 1-4 weeks increased taurine concentration of the extensor digitorum longus (EDL, fast-twitch) muscle of the rat. The uptake of [3H]-taurine into the EDL and tibialis anterior (TA, fast-twitch) muscle was also increased by the stimulation. Concentration and uptake of taurine in the soleus muscle (SL, slow-twitch) did not change by chronic 10 Hz stimulation. Taurine concentration in the SL muscle was significantly reduced by chronic 100 Hz stimulation. This study shows that chronic nerve stimulation increases the uptake of taurine in the fast-twitch muscles, but not in the slow-twitch muscle.

Procoagulant activity and thrombelastography in Korean hemorrhagic fever

Twenty male patients with Korean hemorrhagic fever were evaluated with thrombelastography (TEG) to assess the changes in coagulation system, and the results were compared with those of conventional coagulation tests. Procoagulant activity in the plasma was determined by comparing the reaction time "r" of the normal plasma and that of the mixture of equal parts of the normal plasma and the patient's plasma. The TEG was found to be a useful measure of the changes in the coagulation profile, and provided instant accurate assessment of the patient's hemostatic function. Presence of the procoagulant activity was demonstrated in the plasma of the patients and indicated occurrence of active intravascular coagulation during the early stage of the disease.

Regulation of taurine transport in rat skeletal muscle

Taurine concentration of soleus muscle (SL, slow-twitch) was initially about twofold higher than that of extensor digitorum longus muscle (EDL, fast-twitch). Taurine concentration in gastrocnemius muscle (GC) was intermediate between that of EDL and SL. Four days after sciatic nerve section, taurine concentration in the EDL but not in the SL was increased by 2.5-fold. The increase was not due to the muscle atrophy and was observed 28 days after denervation. Tenotomy did not increase the total taurine content of the EDL. The increase in taurine concentration of the denervated EDL was prevented by simultaneous ingestion of guanidinoethane sulfonate, a competitive inhibitor of taurine transport. The initial and the maximal rates of [3H]taurine uptake were significantly higher in SL than in EDL. Denervation dramatically accelerated the initial and the maximal rates of the transport in EDL, whereas it significantly reduced those in SL. In contrast, the electrical stimulation of sciatic nerve accelerated the uptake of taurine by EDL and SL of the control but not of the curare-treated rats. These results suggest that transport of taurine into rat skeletal muscles is regulated differently by neural information and by muscular activity, and that the regulation is dependent on the muscle phenotype.

Infections in acute leukemia: a retrospective study of 148 patients

To study the nature, offending organisms, consequence, and prognostic factors of infection in acute leukemia, we reviewed the cases of 148 patients admitted to the internal medicine service at Seoul National University Hospital between December 1980 and June 1984. The findings are summarized as follows: (1) The total number of infections was 143, 54% of which occurred after anti-cancer chemotherapy (induction; 28%, maintenance; 14%, reinduction; 10%, consolidation; 2%). Fifty-one percent responded to therapy, and 24% expired due to infection (13%) or other causes (11%). (2) Sixty-four percent of the infections occurred during a granulocytopenic episode (>500/mm³), whereas 36% occurred in the absence of granulocytopenia. When induction, reinduction or consolidation chemotherapy was instituted, infection occurred in 85% of the cases in which granulocytopenia had developed (n=59) and in 50% of the cases in which granulocytopenia had not developed (n=14). (3) Microbiologically documented infection, clinically documented infection and, possible infection accounted for 19%, 47%, and 34% of the total infection episodes, respectively, and in microbiologically or clinically documented infection (n=95), mortality due to infection was 19%, compared to 2% in possible infection (n=48), which was significantly lower (P<.005). Gram negative and positive bacteria accounted for 71.4% and 25.0% of the microbiologically documented infection, respectively, and Pseudomonas species, E. coli, and Staphylococcus aureus were the most common pathogens. Pharyngitis was the most common type of infection to be followed by skin and soft tissue infection, pneumonia and primary septicemia, etc. (4) Eighty-eight and two tenths percent of the patients with bone marrow recovery responded to therapy, a percentage significantly higher than 46 5% for those whose bone marrow function was not restored (P<.005)

Glycerol stress and platelet integrity

Platelet response to glycerol gradient was studied using a few in vitro parameters. These were platelet count, mean platelet size, platelet response to hypotonic stress (PHRS), and collagen-induced platelet aggregation. An equal volume of 1-10% (w/v) glycerol in plasma was added at once to the platelet concentrate resulting in 0.5-5% (w/v) final glycerol concentration. The concentrate was kept at 22 degrees C for 60 min. Platelets were then separated by one centrifugation and resuspended in glycerol-free plasma. A loss in platelet count was observed when the gradient of glycerol was more than 3%. This was associated with an increase in mean cell size and a reduction in aggregability. With 5% glycerol stress, a loss of 30% in cell count, an increase in 18% in cell size, and a 78% loss in aggregability was observed. Declining of PRHS was shown already with a 1% glycerol gradient and 69% of this function was suppressed by 5% glycerol stress. In other experiments, 5% glycerol was first added, them removed in 5 steps with a gradient of 1% each. When time interval between each step was less than 0.5 min, platelet loss and PRHS reduction were 17 and 47% respectively. These values were gradually improved to 4% and 11-20%, respectively, as increasing time interval up to 15 min. It was concluded that a gradient of 1% glycerol and a 15-min interval for each step minimizes the detrimental osmotic stress on platelets while glycerol is added or removed. Our findings may lead up to devising an improved protocol for platelet cryopreservation with glycerol.

Seroepidemiology of human T-cell leukemia virus type-I in the Republic of Korea

We investigated the prevalence of antibodies to human T-cell leukemia virus type I (HTLV-I) associated antigens in various patients and healthy individuals in the Republic of Korea. Seventeen out of 6,255 individuals (0.27%) were seropositive. The positive rate in males was 0.21% and that in females was 0.36%, the sex difference being similar to that in endemic areas in Japan. HTLV-I carriers were found in Seoul and neighboring areas, but not in Busan city or Jeju Island, which are adjacent to Kyushu, Japan. The prevalence of sera with definite anti HTLV-I antibodies seems to be very low in the Republic of Korea.

Diadenosine 5',5'''-p1,p4-tetraphosphate deficiency in blood platelets of the Chédiak-Higashi syndrome

Diadenosine tetraphosphate (AP4A) is an unusual nucleotide found in a variety of cells, including platelets. It has been suggested that platelet AP4A is stored in the dense granules and is metabolically inactive. We have studied the AP4A content of blood platelets in two patients and three cattle with Chédiak-Higashi syndrome (CHS), a hereditary platelet defect with dense granule deficiency. Acid-soluble extractions of whole blood and platelets were neutralized. The adenosine triphosphate (ATP) level was measured by luminescence technique. To measure the AP4A content, the neutralized extract was treated with phosphomonoesterase for removal of ATP. The AP4A content was then measured by coupling the phosphodiesterase and luciferase reaction. The AP4A content was 0.43 nmol/mg protein for normal human platelets and 0.004 nmol/mg protein for CHS platelets. The ATP/AP4A ratio was 67 for normal and 3,023 for CHS platelets. The whole blood AP4A was reduced by 89% in CHS patients who had only a slight decrease in ATP level (26% reduction). Similarly, bovine platelets with CHS showed a marked decrease of AP4A content and a moderate reduction of the ATP level. The platelet ATP/AP4A ratio was 351 and 3,133 for normal and CHS cattle, respectively. Results demonstrate a marked reduction of AP4A in CHS platelets and suggest that AP4A may be a useful marker for the measurement of dense granule content in platelets.

A novel therapeutic approach for reversal of left ventricular hypertrophy and blood pressure control in hypertensive patients treated with alpha-methyldopa or propranolol

A recently added goal in the control of primary hypertension is the reversal of left ventricular hypertrophy which may occur early in the disease and which can have serious consequences. We have attempted to define the hemodynamic parameters which distinguish most sensitively between the long-term effects of two antihypertensive drugs, alpha-methyldopa and propranolol, with a view to determining the optimal conditions under which each of the drugs may be used therapeutically. Twenty matched hypertensive patients, all with established left ventricular hypertrophy, were divided at random into two groups who received either alpha-methyldopa or propranolol as monotherapy. Dosage was titrated until blood pressures were normalized (diastolic blood pressure (DBP) less than or equal to 95 mmHg) (1 mmHg = 133.322 Pa); then therapy was maintained for 48-52 weeks. Supine and erect blood pressures, heart rates, and eight echocardiographic indices were recorded before commencement of therapy and at the 48- to 52-week period. Stepwise discriminant analysis identified erect DBP, erect heart rate, and posterior wall thickness of the left ventricle as being the parameters which distinguished most clearly the therapeutic effects of the chosen drugs. Using these three parameters, all 20 patients were correctly classified into their respective drug groups. We propose that these results may form the basis of a more rational choice of antihypertensive therapy with alpha-methyldopa or propranolol for hypertensive patients based on the initial determination of these three parameters.

Storage iron exchange in the rat as affected by deferoxamine

The initial tissue localization and redistribution of radioactive iron injected intravenously into the rat as ferritin, chondroitin sulfate, and nonviable red cells was determined. Ferritin iron, initially localized in the hepatocyte, showed minimal redistribution over 24 hours in the normal animal. This may be compared with the active release of iron from the reticuloendothelial cell after the intravenous injection of nonviable red cells and chondroitin sulfate iron. All forms of iron were actively mobilized in iron-deficient animals. The effect of chelation of iron by deferoxamine (DFO) on the redistribution pattern over 4 to 6 hours was determined in iron-deficient, normal, iron-loaded, and phenylhydrazine-treated rats to evaluate the effect of iron stores and erythropoiesis. Use of DFO resulted in extensive chelation of radioactive iron within the hepatocyte and greatly reduced the amount of hepatocyte iron available for erythropoiesis. Very little chelation of reticuloendothelial cell-processed iron occurred, and there was little decrease in its utilization for red cell production. Total urinary chelate iron was independent of erythropoiesis but varied in parallel with the iron load of the animal. These studies suggest that DFO does not act on the reticuloendothelial cell but does have at least two sites of action, both of which relate to total storage iron. One involves hepatocyte stores with excretion into the intestinal tract. The other, possibly located at the hepatocyte membrane, results in urinary iron excretion.

The reversal of left ventricular hypertrophy with control of blood pressure in experimental hypertension

The precise mechanisms of hypertensive left ventricular hypertrophy and reversal with antihypertensive drugs are unclear and complex. Enalapril maleate (MK421) and hydrochlorothiazide (HTZ) were used to assess the control of hypertension, and reversal of left ventricular hypertrophy in Dahl sensitive (DS) and Dahl resistant (DR) rats given either a high (8% NaCl), or a low (0.4% NaCl) salt diet. Systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), left ventricular weight/body weight (LVwt/Bwt) ratio were determined. Both drugs were effective in reducing blood pressure and left ventricular mass in DS rats placed on a high salt diet. For DR rats under the same conditions, only MK421 induced significant lowering of blood pressure. Neither drug caused significant change in ventricular mass. Both DS and DR rats on a low salt diet underwent significant blood pressure reduction with MK421 but not HTZ. Significant regression of the left ventricle was observed only in DS rats treated with MK421. Regression was not observed in DR rats even though MK421 reduced blood pressure to distinctly hypotensive levels. The dissociation of left ventricular mass and blood pressure control observed with both MK421 and HTZ suggests that pressure afterload is not the only factor involved in the pathophysiology of hypertensive cardiac hypertrophy. The mechanisms of anti-hypertensive drug action and salt intake both appear to play a significant if unexplained role.

Systolic blood pressure responses to enalapril maleate (MK 421, an angiotensin converting enzyme inhibitor) and hydrochlorothiazide in conscious Dahl salt-sensitive and salt-resistant rats

Systolic blood pressure responses to enalapril maleate (MK 421, a new angiotensin converting enzyme inhibitor (CEI] and hydrochlorothiazide (HTZ) were studied in conscious Dahl salt-sensitive (DS) and salt-resistant (DR) rats maintained on a high salt (8.0% NaCl) and a normal salt (0.4% NaCl) diet. The DS rats were severely hypertensive after 3 weeks on the high salt diet whereas the systolic blood pressure (SBP) of the DR rats were normotensive. Oral treatment with enalapril (15-100 mg X kg-1 X day-1) and HTZ (60-400 mg X kg-1 X day-1) caused a significant reduction of SBP in the DS rats with the high salt diet (P less than 0.001); however, this was not observed until after 4 weeks of treatment when the dosage was 30 and 150 mg X kg-1 X day-1, respectively. Furthermore, enalapril therapy alone significantly reduced the SBP of all groups of rats regardless of diet or Dahl strain (P less than 0.001), but this was not observed until the end of the 7th week of therapy in DR rats on 8.0% NaCl and the end of the 3rd week of therapy for DR and DS rats on 0.4% NaCl. These results suggest that enalapril may lower SBP by mechanisms other than those related to an action as a CEI.

The correlation of changes in systolic blood pressure with regional anatomical regression of hypertensive left ventricular hypertrophy in patients on chronic antihypertensive therapy (greater than 1 year): alpha-methyldopa compared to propranolol

Twenty patients with mild to moderate hypertension and evidence of left ventricular hypertrophy (relative wall thickness greater than or equal to 0.45), who previously had not received either alpha-methyldopa or propranolol, were allocated at random to treatment with one or other of these drugs as monotherapy after a 2-week baseline period on no medication. Dosage was titrated until normotension was attained and patients were then maintained on this treatment for a year. Analysis of blood pressure measurements and echocardiograms taken before and during maintenance therapy showed that there were significantly correlated changes in systolic blood pressure and heart rate with left ventricular cavity and regional wall changes during chronic drug administration. In the alpha-methyldopa group there were significant correlations between changes in erect and supine systolic blood pressure and the posterior wall index, and in erect systolic blood pressure and left ventricular mass. In the propranolol group, there were significant correlations between changes in supine systolic blood pressure and interventricular septal thickness, and in erect heart rate and supine systolic blood pressure with the percentage change in internal diameter of the left ventricle. It is suggested that these observations may have important therapeutic implications for hypertensive patients with documented left ventricular hypertrophy.

Left ventricular changes after chronic therapy with enalapril maleate in moderate to severe hypertensive patients

A randomized double-blind trial was carried out to determine the relationship of the changes in blood pressure and heart rate with changes in echocardiographic left ventricular indices in moderate to severe hypertensive patients with established left ventricular hypertrophy who were being treated chronically with enalapril or hydrochlorothiazide plus propranolol for 26 weeks. After a 2-week period on placebo, drug dosages in the two groups were adjusted to individual needs until blood pressure was normalized (diastolic less than 90 mmHg). Patients in Group I received 10 to 40 mg enalapril/day; those in Group II received 50 mg hydrochlorothiazide plus 80 to 240 mg propranolol/day. Echocardiographic measurements were made at the end of the placebo and 26-week active treatment periods. Significant correlations were observed between the changes in four pairs of variables in each group. In the 8 patients receiving enalapril, there were negative correlations between interventricular septal thickness and supine systolic blood pressure, erect and supine heart rates, and a positive correlation between relative wall thickness and erect diastolic blood pressure. In the 7 patients on hydrochlorothiazide plus propranolol, there were negative correlations between relative wall thickness and erect and supine heart rate, and positive correlations between left ventricular mass and erect diastolic blood pressure, and the percentage change in internal diameter of the left ventricle and supine systolic blood pressure. Possible explanations for and implications of these regional changes are discussed.

Cardiac regression and blood pressure control in the Dahl rat treated with either enalapril maleate (MK 421, an angiotensin converting enzyme inhibitor) or hydrochlorothiazide

Enalapril maleate (MK 421), and hydrochlorothiazide were used to evaluate the control of hypertension and reversal of myocardial hypertrophy in Dahl sensitive (DS) and Dahl resistant (DR) rats given either a high (8% NaCl) or a low salt (0.4% NaCl) diet. Groups of six-week-old male DS and DR rats were treated with enalapril (15-100 mg/kg/day) in drinking water for eight weeks. Additional comparable groups of DS and DR were also treated with hydrochlorothiazide (60-400 mg/kg/day). Systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR) and heart weight/body weight (Hwt/Bwt) ratio were determined. We observed significant reduction in Hwt/Bwt ratio (P less than 0.001) along with control of SBP and DBP in the DS given a high salt diet treated with either enalapril or hydrochlorothiazide. However, in the DR given a high salt diet, cardiac regression (Hwt/Bwt ratio, P less than 0.05), SBP and DBP (P less than 0.01) reduction were seen only with enalapril. Similarly, cardiac regression (Hwt/Bwt ratio, P less than 0.05) was observed along with reduction of SBP and DBP (P less than 0.001) in the DS given a low salt diet and DR given enalapril. These data indicate that enalapril reduced SBP and DBP in association with cardiac regression in hypertensive and normotensive rats. In contrast, hydrochlorothiazide only reduced SBP, DBP and caused cardiac reversal (Hwt/Bwt ratio) in DS placed on a high salt diet.

Separation of essential hypertensive patients based on blood pressure responses after the withdrawal of antihypertensive agents by step-wise discriminant analysis

Thirty-five patients with uncomplicated hypertension were observed for blood pressure behaviour after prolonged antihypertensive medication withdrawal. Twenty-three patients (Group 1) remained normotensive (systolic less than 140 mmHg, diastolic less than 95 mmHg) for over 60 weeks compared to 12 patients (Group 2) who became hypertensive again during a 4-week placebo period. Discriminant analysis was performed on 31 clinical and laboratory variables measured before therapy to separate any discriminating factors for the two groups. Four variables maximized the separation of Group 1 from Group 2 patients. In descending order, these were serum sodium (p less than 0.001), mean corpuscular volume (p less than 0.01), serum albumin (p less than 0.01), and body weight (p less than 0.05). Using these four variables 73.9% of patients in Group 1 and 75% of patients in Group 2 were classified correctly into their respective groups. It is suggested that this observation may be useful in the development of new therapeutic regimens for patients with uncomplicated essential hypertension, for example by predicting those patients who may respond favourably to intermittent therapy or even to its withdrawal.

Normal ventilatory movement of the right hemidiaphragm studied by ultrasonography and pneumotachography

The ventilatory movement of the right dome of the diaphragm was studied over the range of the inspiratory capacity in 50 healthy adults in the supine position using simultaneous ultrasonography and pneumotachography. Regional differences were found in movement of the hemidiaphragm; there was greater movement of the middle and posterior thirds of the diaphragm than of the anterior third. A significant positive correlation was found between body weight and amount of diaphragm movement. An apparently greater degree of movement of the diaphragm was found in males than females; this may be related to weight. About 64% of diaphragm movement has occurred by the time midinspiratory capacity is reached. These data may help to define normal movement and also to differentiate abnormal from normal diaphragm movement.