Renal dopaminergic activity in patients with primary aldosteronism

To clarify the role of renal dopaminergic activity in patients with primary aldosteronism (PA), urinary excretion of free dopamine (DA) and the conversion ratio of DA from l-dopa in the kidney were investigated in 8 patients with PA and 10 normotensive subjects (NT). All subjects were hospitalized and received a standard diet (Na 120 mEq, K 75 mEq/day) and 2 h renal clearance test was performed. Plasma l-dopa concentration (p-DOPA), creatinine clearance (Ccr), urinary excretion of sodium (UNaV) and DA (uDA) as well as fractional excretion of sodium (FENa) were measured. No significant difference was found in UNaV or FENa between NT and PA, or between before and after adrenalectomy (Adx) in PA. UDA was significantly higher in PA than NT, and decreased significantly after Adx. There was no difference in the product of Ccr X p-DOPA between NT and PA, or between before and after Adx in PA. The ratio of uDA/(Ccr X p-DOPA) was significantly higher in PA than NT. After Adx this ratio decreased significantly to the normal range. These results suggest that (1) renal dopaminergic activity is augmented and contributes to the escape phenomenon in PA, and (2) augmented renal DA production in PA might be caused by an increase of conversion to DA from l-dopa at the renal proximal tubules.

Digestion of endothelin-1 on cultured vascular smooth muscle cells

The degradation of 125I-endothelin-1 (125I-ET-1) was examined on cultured porcine aortic endothelial cell (EC) and rat vascular smooth muscle cell (SMC) by HPLC analysis. The degradation of ET-1 was observed on SMC and was slightly observed on EC. Membrane fractions of SMC had a strong potency for the degradation of ET-1 and retained activity even in plasma. This activity was inhibited with some of the noble inhibitors which were known as enkephalinase inhibitors. These results suggest that endothelin degradation enzyme on SMC is related to enkephalinase and that this enzyme plays a significant role in the degradation of ET-1 in vivo.

[A case of complete response by intermittent intra-arterial injection of 5-fluorouracil and carboplatin for liver metastases due to pancreatic cancer]

A 53-year-old woman with multiple liver metastases after pancreato-duodenectomy for pancreas cancer was inserted with a catheter from the left subclavian artery to the proper hepatic artery and an access was placed under the thoracic skin. Using this system, she was injected with 500 mg of 5-fluorouracil and 50 mg of carboplatin once a week. After about 7 months, liver metastases disappeared on ultrasonography and computed tomography scan. The patient is still free from recurrence after about 2 years from the initial chemotherapy. This result suggested that intermittent intra-arterial infusion of 5-fluorouracil and carboplatin is effective for liver metastases of pancreatic cancer, after curative resection of a primary tumor.

Differential diagnosis of adrenal tumour and upper pole renal tumour by I-131 cholesterol adrenocortical scintigraphy

A 27-year-old housewife with right hypochondralgia was admitted for treatment of a huge right adrenal or upper pole renal tumour. The tumour measured 10 x 8 x 8 cm and was hypovascular. The main blood supply derived from the right adrenal artery which originated from the abdominal aorta just proximal to the right renal artery. Although several diagnostic imaging studies suggested that the tumour arose from the right adrenal gland, the bilateral adrenal glands were equally visualized on I-131 cholesterol adrenocortical scintigraphy. After surgery and pathological examination, the tumour proved to be a renal cell cancer, while the right adrenal gland was intact. This case demonstrates that adrenocortical scintigraphy is useful in the differentiation of adrenal and renal tumours when a large tumour occupies the upper pole of the kidney or adrenal gland.

Induction of dyspnea by aerosol of endothelin-1/histamine or/methacholine in the conscious guinea pig

The inhalation of aerosol of endothelin-1 (ET-1) induced dyspneal behavior in conscious guinea pigs pretreated with histamine or methacholine inhalation, although it was not observed by the inhalation of ET-1 alone. The dyspneal response to the inhalation of ET-1/histamine was potently inhibited by indomethacin, but it was not affected by nifedipine or diphenhydramine.

Syntheses and biological activities of endothelin-1 analogs

Endothelin-1 analogs replaced by various amino acids at position 21, namely [X21]-ET-1, were synthesized, and their agonistic vasoconstrictor activity on rat thoracic aortic strips and receptor binding activity on rat brain membrane fraction were examined to elucidate their structure-activity relationship. The vasoconstrictor activities of [Tyr21]- and [Phe21]-ET-1 were one order of magnitude smaller than that of ET-1, and those of [His21]-, [Gly21]-, [Ser21]-, [Ala21]- and [Lys21]-ET-1 were more than two orders of magnitude smaller than that of ET-1. On the other hand, the replacements by Ile, Glu, Gln and Pro resulted in distinguished losses of the vasoconstrictor activities. In addition, preincubation with these analogs did not blunt ET-1-induced vasoconstriction and showed no antagonistic activity. The binding inhibitory activities of these analogs against 125I-ET-1 were approximately conformable to the vasoconstrictor activities with only a slight exception. These findings demonstrate that the phenyl group at position 21 is important for both the vasoconstrictor activity and the receptor binding activity.

Inhibition of endothelin (ET)-1-and ET-2-induced vasoconstriction by anti-ET-1 monoclonal antibody

We produced a monoclonal antibody to endothelin (ET)-1, tested cross-reactivities with the related peptides by enzyme immunoassay, and investigated the effects of the antibody on ET-1- or ET-2-induced vasoconstriction of rat isolated thoracic aorta. The antibody recognized ET-1, ET-2 and ET-3, and the immunoreactive site proved to be the N-terminal region but not the C-terminal region of ET-1. Moreover, at an approximate molar-equivalent concentration, the antibody absorbed ET-1 and ET-2, and significantly inhibited ET-1- and ET-2-induced vasoconstriction notwithstanding the presence of the endothelin receptor.

Clinical results of tubeless cutaneous ureterostomy by Toyoda's method

Tubeless cutaneous ureterostomy by Toyoda's method was conducted in 67 ureters from 43 patients during the last 9 years. Subjects included 30 males and 13 females, with an average age of 61.4 years. Most of them were afflicted with malignant tumors in the bladder, rectum, prostate, or uterus. For bilateral ureterostomy, the double-barrel method was performed in which the stoma was made at the same site in both the right and left ureters. Among 60 ureters in which pre- and postoperative changes in the renal pelvis could be traced by IVP, satisfactory results were obtained in 16 of 20 ureters treated by unilateral surgery. Of the 40 ureters treated by the double-barrel method, moderate or severe pyeloectasis was observed in 3 of the 20 ureters on the side of the stoma, while moderate pyeloectasis was seen in 3 of 20 ureters of the side opposite the stoma, and severe pyeloectasis or loss of renal function was noted in 5. Thus, renal function on the side opposite the stoma was frequently influenced by the procedure. A patient who died of disseminated intravascular coagulation syndrome soon after the operation was excluded from analysis. Tubeless cutaneous ureterostomy could be conducted in 39 of 42 patients (92.8%), excluding one whose stoma and its periphery were covered with severe inflammatory granulation and 2 with ureteral constriction.

[A case of non-Hodgkin's malignant lymphoma with a lymphoma nodule moving around within a lung bulla]

A 53-year-old man was admitted to Nagoya City University Hospital with complaining of bloody sputum and an abnormal shadow on chest X-ray film. The chest X-ray film showed a giant bulla in the right upper and middle lung fields and a mass shadow inside the bulla. In addition he had the swelling of bilateral inguinal lymph nodes. He was suspected to having bleeding from the lung bulla, and received a right upper lobectomy. The resected specimen showed a lobular tumor in the parenchyma of lung and an oval lymphoma nodule moving around inside of lung bulla. Histologically, both the lung tumor and inguinal lymph-nodes were non-Hodgkin's malignant lymphoma, diffuse and plasmacytoid large cell type.

[Clinical study of tumor markers in prostatic cancer]

We measured prostatic acid phosphatase (PAP), gamma-seminoprotein (gamma-Sm) and prostatic specific antigen (PSA) levels simultaneously in the serum of 52 patients with untreated prostatic cancer and 44 patients with benign prostatic hypertrophy to assess the clinical usefulness of these tumor markers. PAP and PSA were measured by radioimmunoassay and gamma-Sm by enzyme immunoassay. The positive rates of PAP, gamma-Sm and PSA in patients with prostatic cancer were 50.0, 61.5 and 69.2%, respectively, and those in patients with benign prostatic hypertrophy were 11.4, 13.6 and 13.6%, respectively. In patients with early stage prostatic cancer (stage A and B), the positive rates of PAP, gamma-Sm and PSA were 20.8, 41.7 and 54.2%. The efficiency of PSA was the highest among the three markers. The positive rate of the combination assay of PAP and PSA, that of gamma-Sm and PSA and that of PAP, gamma-Sm and PSA were slightly higher than that of the PSA assay alone. However, the efficiency of the PSA assay alone was higher than that of any combination. No significant correlation was found between histopathological grade and the level of each tumor marker. A significant correlation was found between PAP and gamma-Sm (r = 0.68, P less than 0.001), and between PAP and PSA (r = 0.61, P less than 0.001), but there was no correlation between gamma-Sm and PSA. These results suggest that PSA is the most useful marker and the combination assay of multiple markers is not so advantageous, at least for screening of prostatic cancer.

[Primary malignant mesothelioma of the pericardium masquerading as malignant pleural mesothelioma: report of an autopsy case and review of the reported cases in Japan as to its invasion to neighboring organs]

The Patient was a 72-year-old man who presented with dyspnea and general fatigue. Chest X-ray and CT-scan at the admission showed bilateral pleural effusion with collapse of the left lung and pericardial effusion. Cytology from the left pleural effusion suggested malignant mesothelioma. For this reason, malignant mesothelioma of the left pleura was diagnosed clinically and it was supposed to have spread subsequently to the pericardium. At autopsy, entire surface of the heart was found to be encroached in a diffuse fashion by a thick layer of mesothelioma tissues, which formed a small mass around the left pulmonary vein over the left atrium and invaded deep into the myocardium of all cardiac chambers. The endocardium and the intima of the left pulmonary vein were free of the invasion. The parietal pericardium adhered in places to the cardiac lesion, but no direct invasion to the adjacent pleurae through the pericardial wall was present. The left pleura over the lung and chest cavity disclosed only a superficial invasion by similar mesothelioma which was identifiable only on microscopic study. No distant metastasis was present in any thoracic and other organs as well as lymph nodes including the hilar ones of the lung. It seemed most likely from this anatomical finding that the primary site of the present mesothelioma was in the pericardium (visceral) and the tumor spread to the left pleura by a continuous extension along the outside of the left pulmonary vein. Primary malignant mesothelioma of the pericardium is of very rare occurrence and we found only 51 cases of it in the Japanese literature since 1915.(ABSTRACT TRUNCATED AT 250 WORDS)

Electrical resistance of appliances as a cause of urethral stricture following transurethral resection of prostate

We performed transurethral resection for prostatic hypertrophy on 128 patients, and encountered 6 causes of postoperative urethral stricture. As they occurred during a short period, we investigated the causes. An electrical check revealed electrical resistance of more than 10,000 omega in the electric cord of a resectoscope. When an unused loop was connected with three used cords (No. 1, 2 and 3) and a new cord, the resistances were 2,000, 5,000, 0.9 and 0.5 omega, respectively. Moreover, the respective resistances were 15,000, 1,150,000, 1.3 and 0.9 omega when a used loop was tested. These findings suggested that the excessive resistance resulted from the use of a worn cord and that the used loop caused the postoperative urethral stricture.

Effects of a new thromboxane A2-antagonist (ONO-3708) and a new leukotriene-antagonist (ONO-1078) on thromboxane A2 analogue-, leukotriene C4-, and D4-induced regional myocardial blood flow reduction

Effects of the administration of a thromboxane A2 (TXA2) analogue (STA2), a leukotriene C4 (LTC4), and a leukotriene D4 (LTD4) on regional myocardial blood flow (RMBF) and hemodynamics were studied in anesthetized, open-chest dogs. The blocking ability of a recently synthesized TXA2 selective antagonist, ONO-3708, and a peptidoleukotriene-selective antagonist, ONO-1078, was also investigated. RMBF was measured continuously in three areas: the left anterior descending coronary artery (LAD) area, the circumflex artery (Cx) area, and the area between LAD and Cx. STA2, LTC4, and LTD4 caused a significant dose-dependent reduction of the RMBF in the LAD area. The peak percentage decrease in RMBF followed by a 10 micrograms dose of STA2, 1 micrograms dose of LTC4, and 1 micrograms dose of LTD4 is 38.6% +/- 3.0%, 39.0% +/- 3.1%, and 36.2% +/- 2.4%, respectively. ED50 for the action of LTC4, LTD4, and STA2 on RMBF is 3, 3, and 50 micrograms, respectively. Pretreatment with the newly developed TXA2 antagonist, ONO-3708 (1 micrograms/kg/min for 10 min), completely inhibited the RMBF reduction induced by STA2 (10 micrograms). Pretreatment with the peptidoleukotriene antagonist, ONO-1078 (1 mg), inhibited the RMBF reduction induced by LTC4 or LTD4 (0.3-3 micrograms). Following pretreatment with a 1 mg dose of ONO-1078, the peak percentage decrease of RMBF caused by a 1 micrograms dose of LTC4 and LTD4 was reduced to 21.1% +/- 2.3% and 19.8% +/- 3.1%, respectively. However, the LTC4 (1 micrograms)-induced reduction of the RMBF was not affected by pretreatment with a TXA2 antagonist, ONO-3708, or an inhibitor of the endogenous production of TXA2, OKY-046.(ABSTRACT TRUNCATED AT 250 WORDS)

The effects of lipoxygenase inhibitor and peptidoleukotriene antagonist on myocardial injury in a canine coronary occlusion-reperfusion model

We studied effects of lipoxygenase inhibitor (AA-861) and peptidoleukotriene antagonist (ONO-1078) on infarct size, polymorphonuclear leukocyte (PMNs) infiltration, gross myocardial hemorrhage and ventricular arrhythmias in canine coronary occlusion (2 hr)-reperfusion (5 hr) model. Infarct size (IS) and risk area (RA) were determined by dual staining technique. Thirty minutes before coronary occlusion dogs were randomly assigned to one of the following three groups: lipoxygenase inhibitor group (n = 11) receiving AA-861 3 mg/kg i.v., peptidoleukotriene antagonist group (n = 11) receiving continuous intravenous infusion of ONO-1078 1 micrograms/kg/min and vehicle control group (n = 15). Both AA-861 and ONO-1078 reduced infarct size [AA-861: 21.8 +/- 1.3% of RA (mean +/- SEM), ONO-1078: 22.5 +/- 4.4% vs

CONTROL

54.0 +/- 6.4%, p less than 0.01 and p less than 0.01, respectively] and area of gross myocardial hemorrhage (AA-861: 5.1 +/- 2.4% of IS, ONO-1078: 5.2 +/- 2.5% vs

CONTROL

22.3 +/- 3.9%, p less than 0.01 and p less than 0.01, respectively). Both drugs also decreased frequency of ventricular premature contractions both during occlusion and during reperfusion, and that of ventricular tachycardia during reperfusion. AA-861 inhibited PMNs recruitment into infarcted area. However, ONO-1078 had no significant influence on degree of PMNs infiltration. These results suggest that lipoxygenase products, especially peptidoleukotrienes (LTC4, D4 and E4) may play important roles in the pathogenesis of myocardial ischemic and reperfusion injuries.

Reduced pulmonary toxicity of peplomycin in a new drug-delivery system

Pulmonary toxicity was examined by means of Matsuda and Takahashi's procedure in peplomycin solution, and two types of a new dosage form of peplomycin (PEP-CH), which has peplomycin adsorbed on to activated carbon particles. One was PEP-CH IP, and is designed for intraperitoneal administration. The other was PEP-CH IM, for intramuscular administration. Male mice of ICR strain received a bolus injection of 50 mg kg-1 peplomycin in the form of aqueous solutions PEP-CH IP and PEP-CH IM. The survival rate was 100% after 5 weeks in both groups that were administered PEP-CH. The rate was 50% for the group given peplomycin solution intraperitoneally, and 70% for the group given peplomycin solution intramuscularly. Five weeks after administration the mice were killed, and the grade and the incidence of pulmonary fibrosis were evaluated histologically. The grade and incidence of pulmonary fibrosis were zero in the two groups given PEP-CH. The grade was 0.33 and 1.76, and the incidence was 60% and 86%, respectively, in the group given peplomycin solution intraperitoneally and in the group given peplomycin solution intramuscularly.

Activated carbon particles as anti-cancer drug carrier into regional lymph nodes

The effect of a new dosage form for anti-cancer agents was studied on tissue distribution and compared with the aqueous solution form. The new dosage form, developed in order to distribute a greater amount of the agent to regional lymph nodes, comprises polyvinylpyrrolidone and small activated carbon particles adsorbing pepleomycin (PEP-CH) or mitomycin C (MMC-CH) in saline. Pepleomycin at 500 micrograms/kg or mitomycin C at 250 micrograms/kg were injected into the gastric wall of dogs in the new dosage form or the aqueous solution form. The activity level of the agents in tissues was bioassayed within 24 h after injection by the thin agar plate method. Statistically, the new dosage form maintained an activity level in lymph nodes that was significantly higher than the aqueous solution form (ratio of PEP-CH to solution form, 6-32 times in 24 h; MMC-CH, 100-1000 times in 6 h; p less than 0.05-0.01), and a concentration in blood that was significantly lower (PEP-CH, about 1/2 times in 2 h; MMC-CH, 1/10-1/5 times in 1 h; p less than 0.05).

Anticancer agents adsorbed by activated carbon particles, a new form of dosage enhancing efficacy on lymphnodal metastases

A new dosage form consisting of small activated carbon particles which adsorb Aclacinomycin A, Adriamycin, Mitomycin C or Pepleomycin was prepared in order to deliver larger amounts of anticancer agents to the lymph nodes through the high ability of lymphatics to adsorb particles. Animal experiments showed that: The LD50 values of the new dosage form were higher than those of the dosage in solution. The concentration of agents in lymph nodes was maintained at a higher level in the new dosage form than in solution form. Clinically 33% of lymphnodal metastatic lesions became degenerative or inflammatory after a single administration.

[A case of male breast cancer with special reference to the hormonal environment during chemoendocrine therapy]

Chemoendocrine therapy was performed on a man with advanced breast cancer, and partial response was observed for 11 months. Estrogen receptor in cancer tissue was detected before and after the therapy. Progesterone receptor, however, was not detected after the treatment, whether it had been there or not prior to it. The serum estrone level was continuously high during the treatment, but the serum testosterone level was obviously decreased after that.

Immunosuppressive activity of sera from gastric cancer patients

Sera from 60 gastric cancer patients and 20 patients with benign gastric diseases and 8 healthy controls were tested for inhibitory effects on the humoral response to sheep erythrocytes (SRBC) by the plaque forming cell assay (PFC R.I.) using mouse spleen cells and on the phytohemagglutinin (PHA)-induced blastogenesis of normal mouse spleen cells (PHA S.R.). Gastric cancer patient sera showed a significantly lower PFC R.I. than did sera from benign gastric disease patients and from the healthy controls. However, there was no appreciable interstage difference in the degree of depression. The PHA-induced blastogenesis of normal spleen cells was also decreased in the presence of sera from cancer patients, as compared to that in the presence of sera from benign disease patients and from the healthy controls. The depression progressed with advancing stage of cancer. The PHA S.R. showed significant negative correlations with serum levels of IAP, IS, alpha 1-acid glycoprotein and alpha 1-antitrypsin, but there were no such correlations between PFC R.I. and these glycoproteins in serum. There was also no correlation between the values of the PHA S.R. and the PFC R.I. These results suggest that these two assays may depict immunosuppressive activities operating through entirely different mechanisms.

Intratumor chemoimmunotherapy with mitomycin C and BCG in C3H/He mice transplanted with MH134

Experiments were performed to explore the influence of local chemoimmunotherapy by intratumoral administration of mitomycin C (MMC) and/or BCG on the survival rate, lymph-node metastasis, growth pattern of rechallenge tumor, and host immune function, using a host-tumor system consisting of C3H/He mice and syngeneic tumor MH134. Combined intratumoral regimens of MMC plus BCG yielded a significantly higher survival rate than those achieved with BCG or MMC alone. Furthermore, the incidence of metastatic involvement of regional lymph nodes was also remarkably reduced in the combined regimen group. The group given the combined MMC-BCG regimen also showed a marked suppression of the growth of rechallenge tumor after surgical removal of the primary tumor and showed a greater induction of tumor-specific immunity than that seen in the group given intratumoral BCG injection alone. Both the delayed-type hypersensitivity, as measured by the footpad swelling assay, and the antibody response in spleen lymphocytes, as estimated by the plaque-forming cell assay, were found to be substantially depressed following a systemic injection of MMC, whereas the intratumoral administration of MMC had little or no effect on these parameters.

Intratumor immunochemotherapy with 5-fluorouracil emulsion and BCG in C3H/HE mice transplanted with MH134

Responses to intratumor immunochemotherapy by intralesional injections of BCG and 5-fluorouracil (5-FU) emulsion, prior to resection of a transplanted primary tumor, were investigated using a host-tumor system consisting of C3H/He mice and MH134. A significant prolongation of survival and suppression of lymph node metastasis were attained by the combined use of BCG and 5-FU emulsion, compared to treatment with either BCG or 5-FU emulsion alone. However, this did not alter the survival rate of the combined regimen group as compared with those of the latter treatment groups. When rechallenged with the same tumor cells after resection of the primary lesion, mice treated with BCG alone exhibited a marked tumor growth suppression while the control and BCG + 5-FU emulsion group showed a less effective suppression. No such effects were observed in the group given 5-FU emulsion alone. Assessment by the splenic plaque-forming cell assay with sheep erythrocytes revealed a marked inhibition in the development of humoral immunity in the animals treated with 5-FU emulsion alone. Concomitant administration of BCG was effective to some extent in preventing the depression of these immune functions. The data obtained indicate that the clinical response to immunochemotherapy is determined by a balance between the antitumor effect of the antitumor agent administered and its influence on the host's immune functions.

[Experimental study on local immunochemotherapy]

The purposes of this work were twofold: firstly to determine whether intratumor chemoimmunotherapy was more effective than either treatment alone or systemic therapy and; secondly to study how the intratumor therapy affected on the development of the tumor-specific immunity. Inbred male C3H/He mice and mouse ascited hepatoma 134 (MH 134) of C3H origin were used as host-tumor system. Mitomycin C was used as the chemotherapeutic agent and BCG as the immunopotentiating agent. Intratumor treatment of MMC + BCG led to complete cure in 85 percent of the mice. The lymph node metastases were markedly inhibited in the group treated with MMC + BCG compared to the groups treated with MMC alone or BCG alone. The growth of rechallenged tumor was investigated; 79% of mice treated with MMC + BCG were immune to rechallenge, whereas 57% of mice treated with BCG alone. The number of PFC and DTH against SRBC of the mice treated with MMC intraperitoneally significantly decreased compared to that treated with MMC intratumorally.

[Clinical evaluation of the serum level of immunosuppressive acidic protein (IAP) and immunosuppressive substance (IS) in gastric cancer patients]

Recently, immunosuppressive acidic protein (IAP) and immunosuppressive substance (IS) were reported by two institutions, and they have been currently under extensive clinical investigations. As these two acidic proteins seemed to be very similar glycoproteins, we tried to elucidate clinically the dissimilarities between these two substances. The mean value of IAP of 106 healthy donors was 378 +/- 100 micrograms/ml, and as 95% of them was under 550 micrograms/ml, therefore, the upper limit of normal value of IAP was determined to be 550 micrograms/ml. On the other hand, the mean value of IS was 553 +/- 125 micrograms/ml and the upper limit of normal value was 750 micrograms/ml. In 110 gastric cancer patients, the incidence of the abnormal value of IS (43%) was higher than that of IAP (33%), and abnormal values were observed at earlier stage in IS than that observed in IAP. The reaction of skin tests was more highly correlated with the value of IS than the value of IAP. From these facts, it was suggested that the value of IS was more predictable than that of IAP as the parameter of the immunosuppression of the gastric cancer patients.

[Effect of PSK on DMH (dimethyl hydrazine) induction of cancer]

The effect of PSK on the induction of intestinal tumors by DMH in Wistar rats was examined. One hundred and fifty-one rats were divided into two groups. Seventy-two rats were treated with DMH alone and 79 rats were treated with DMH and PSK. All animals were subjected to a sequential autopsy and all lesions within the GI tract were examined macroscopically and histologically. Tumor incidence in the DMH and PSK treated group was significantly lower than that in the DMH treated alone, and peritoneal disseminations and distant metastases were also significantly decreased in the PSK treated rats. The number of circulating lymphocytes dropped in the 25th and 35th week in the group treated with DMH alone, but the drop in the PSK treated group was not remarkable. DTH reaction to PPD and antibody forming capacity to SRBC were well maintained in the PSK treated rats than in those treated with DMH alone. The most interesting findings in these experiments were the differences concerning the serum blocking activities and serum immunosuppressive factor in these two groups; these were markedly reduced in PSK-treated rats. From these experiments, the mechanisms may be explained by the competitive action of PSK against the immunosuppressive factor produced by a tumor-bearing host.

Antarcticite: A New Mineral, Calcium Chloride Hexahydrate, Discovered in Antarctica

A new mineral, calcium chloride hexahydrate, was discovered in the Don Juan Pond in Victoria Land, Antarctica. The optical properties, chemical analysis, and powder patterns obtained by x-ray diffraction agree with those of artificial calcium chloride hexahydrate. The name Antarcticite is proposed for the new mineral.