Diagnosis of germinal neoplasm in the thalamus and basal ganglia

Germinal neoplasms originating in the thalamus and basal ganglia were histologically verified by stereotactic biopsies in five cases and by other methods in three cases. Immunoperoxidase staining was performed on the tumors using antibodies against human chorionic gonadotropin and placental alkaline phosphatase. The presence of human chorionic gonadotropin was demonstrated in one germinoma and two mixed tumors, but not in three germinomas. Placental alkaline phosphatase was demonstrated to be present in four germinomas and one mixed tumor. Stereotactic biopsy specimens can be studied immunohistochemically, and the placental isoenzyme of alkaline phosphatase appears to be a new tumor marker for germinoma.

Germ cell tumor in the basal ganglia: immunohistochemical demonstration of alpha-fetoprotein, human chorionic gonadotropin, and carcinoembryonic antigen

A case of germ cell tumor in the basal ganglia and its vicinity was successfully treated surgically and by radiation. alpha-Fetoprotein, human chorionic gonadotropin, and carcinoembryonic antigen were found in the tumor tissue, using the immunoperoxidase method. The presence of three immunohistochemically demonstrated tumor markers in a single germ cell tumor is extremely unusual. These results strongly suggest a cell differentiation or transformation in germ cell tumors.

Corticotropin-releasing factor (CRF) and vasopressin concentration in major brain regions after adrenalectomy and their involvement in adrenalectomy-induced ACTH elevation

CRF and vasopressin concentrations in major brain regions after bilateral adrenalectomy and their involvement in adrenalectomy-induced ACTH secretion were investigated. At 5, 14 and 28 days after bilateral adrenalectomy, the plasma ACTH level was greatly elevated, whereas hypothalamic CRF content was reduced at 5 days and was not changed at 14 and 28 days after adrenalectomy. The CRF concentration in the medulla oblongata was reduced at 2-4 weeks after adrenalectomy. On the other hand, the arginine vasopressin (AVP) concentration was significantly elevated 2-4 weeks after adrenalectomy. An intrajugular administration of anti-ovine or anti-rat CRF serum significantly suppressed the elevated plasma ACTH level in adrenalectomized, freely moving rats, whereas anti-AVP serum or antipressor AVP antagonist, dpTyr(Me)AVP did not suppress the ACTH level. These results indicate that CRF played an important role in the adrenalectomy-induced ACTH elevation but that vasopressin was not involved.

Effects of intravenous and intraventricular injection of antisera directed against corticotropin-releasing factor on the secretion of anterior pituitary hormones

To determine the physiological significance of corticotropin-releasing factor (CRF) in the control of pituitary hormone secretion, highly specific antibodies directed against the peptide were injected either intravenously or intraventricularly (third ventricle) and the effect on plasma levels of pituitary hormones was determined before and after application of ether stress for 1 min. The intravenous injection of CRF antiserum (0.5 ml) did not significantly alter basal corticotropin (ACTH) levels in freely moving ovariectomized rats but largely blocked the increase in plasma ACTH resulting from ether stress. These antibodies had no effect on the ether-induced decline in plasma growth hormone (GH), and they failed to modify plasma luteinizing hormone levels. In a second experiment, CRF antiserum (3 microliter) or normal rabbit serum was injected into the third ventricle. A blood sample was drawn 24 hr later and immediately thereafter another injection of CRF antiserum or normal rabbit serum was made. There was no modification in the level of any of the hormones 24 hr after the first injections, and they were similar in CRF antiserum and normal rabbit serum-injected animals. After imposition of ether stress, the response of plasma ACTH was nearly completely blocked by the intraventricular CRF antiserum, but the degree of blockade was slightly less than that obtained by intravenous injection. The decline in plasma GH after ether stress was blocked by the intraventricular CRF antiserum. There was no effect of the intraventricular injection of the antiserum on the levels of the other pituitary hormones. The results with intravenous injection of the antisera indicate that CRF plays an extremely important but probably not completely indispensable role in the release of ACTH after ether stress. The results of the intraventricular injection of the antiserum suggest strongly that endogenous CRF may also modify its own release in response to stress, augmenting it by a positive ultrashort loop feedback, and that the antisera against the peptide blocked this action; however, an action at the pituitary of these intraventricularly injected antibodies cannot be completely ruled out. The blockade of the stress-induced suppression of GH release by the CRF antibodies suggests that CRF released intrahypothalamically during ether stress brings about an alteration in the hypothalamic control of GH secretion such that the stress-induced inhibition of GH release is blocked.

Role of the central muscarinic receptor of prostaglandin I2 in cardiovascular function in rat

The effects of injection of prostaglandin (PG) I2 into the cerebral ventricle on cardiovascular responses and their modification by intracerebroventricular (i.c.v.) pretreatment with several drugs were studied in male Wistar rats under urethane anesthesia. When injected into the ventricle, PG I2 (50 nmol/kg) caused a decrease in blood pressure and an increase in heart rate which were of short duration and were significantly inhibited by i.c.v. pretreatment with drugs, such as atropine (0.4 mumol/kg) and diphenhydramine (1 mumol/kg), having an anticholinergic effect. The similar effects induced by intravenous (i.v.) injection of PG I2 (5 nmol/kg) were not inhibited by i.v. pretreatment with these drugs. These results suggest that PG I2 play a role in regulation of cardiovascular function through central muscarinic acetylcholine receptors.

Successful treatment of a basilar aneurysm presenting as a brainstem hemorrhage

A case of large brainstem hemorrhage resulting from a basilar artery aneurysm is reported. This extremely rare disorder is fatal in a large majority of cases, and has usually been reported after autopsy. This case presents a successful recovery after clipping the aneurysm.

Intrahypothalamic action of corticotrophin-releasing factor (CRF) to inhibit growth hormone and LH release in the rat

The effects of intravenous or intraventricular injection of synthetic ovine corticotrophin-releasing factor (oCRF) on plasma levels of anterior pituitary hormones were studied in conscious, ovariectomized (OVX) female rats and compared with the actions of the peptide on dispersed anterior pituitary cells from OVX female rats incubated in the presence of CRF. Third ventricular injection of oCRF in freely moving rats caused a significant increase in plasma levels of ACTH in a dose-related manner with a minimal effective dose of less than 0.5 micrograms (0.1 nmol). The effect was observable at 5 min after injection and persisted for the 60 min duration of the experiment. In contrast, growth hormone levels were significantly depressed within 15 min with a minimal effective intraventricular dose of 0.5 micrograms. The suppression persisted for the duration of the experiment but there was no additional effect of the higher dose of 5 micrograms. Plasma LH levels were also lowered by the highest dose of 5 micrograms (1.0 nmol) of oCRF, with the first significant lowering at 30 min. Lower doses had no effect on plasma LH. Plasma TSH levels were not significantly altered. Control injections of the 0.9% NaCl diluent were without effect on the levels of any of the hormones. Intravenous injection of similar doses of oCRF had no effect on plasma levels of GH or LH. The ACTH-releasing action of the oCRF preparation was confirmed by in vitro incubation of the peptide with dispersed anterior pituitary cells for 2 h. A dose-related release of ACTH occurred in doses ranging from 0.1-10 nM, but there were no effects on the release of the other anterior pituitary hormones. The results suggest that oCRF may act within the hypothalamus to suppress the release of GH and to a lesser extent LH. The stimulation of ACTH release following intraventricular CRF is presumably related to its uptake by portal blood vessels with delivery to the pituitary and stimulation of the corticotrophs.

Synthesis of flagellin and hook subunit protein in flagellar mutants of Escherichia coli K12

We have examined Escherichia coli K12 flagellar mutants affected in each of 29 different loci for the synthesis of flagellin and hook subunit protein. Immune precipitation experiments were employed by treating cell extracts with antiserum against each protein. Flagellin was synthesized in mutants defective in genes flaS , flaT, flaU and flbC . The flaE and flaZ mutants produced small amounts of flagellin, while all the other mutants failed to produce any detectable amount of flagellin. Hook subunit protein was found in most mutants including those defective in genes flaA , flaB , flaC, flaD , flaE , flaG , flaH , flaL , flaM , flaN , flaO , flaP, flaQ , flaR , flaS , flaT, flaU , flaV , flaW , flaX, flaY , flaZ , flbA , flbC , flbD , and hag but not in mutants of flaK , flaI , and flbB . The results conform to the predictions made by our previous indirect gene fusion study ( Komeda 1982).

Bacteriophage chi sensitivity and motility of Escherichia coli K-12 and Salmonella typhimurium Fla- mutants possessing the hook structure

The production of hook protein and flagellin in 29 Fla- mutants of Escherichia coli K-12 was determined by the complement fixation assay. Six mutants produced hook protein, and four of them also produced flagellin. A flaE mutation was introduced into these fla mutants carrying the hook structure. All of these mutants made polyhooks and were used as hosts for a newly isolated host-range mutant of chi phage that has a high affinity for the hook structure. All except one mutant produced significant amounts of progeny phages. A flaD flaE double mutant was that exception which did not yield significant amounts of progeny by the phage propagation method. All of the flaE double mutants produced comparable amounts of polyhooks, and no qualitative difference was detected between chi-sensitive and chi-insensitive mutants by the complement fixation assay. Accordingly, it was thought that the polyhook of the flaD flaE mutant had a mechanical defect for chi phage infection. This assumption was confirmed by tethered-cell experiments; the flaD flaE mutant did not rotate. These results are well explained by a proposed regulation pathway of flagellar genes. flaE mutants can express other genes which govern the final step of the flagellar morphogenesis, whereas flaD mutants cannot rotate, possibly because the mocha operon is not expressed. The results obtained in E. coli were also found to be applicable to Salmonella typhimurium.

[Primary malignant lymphoma of the spleen in a long surviving patient and review of the literature]

A case of primary malignant lymphoma of the spleen is presented. The tumor was successfully removed and eight years after the surgery, the patient died without any recurrence of the malignant lymphoma. A review of the literature, with special reference to prognosis is also presented. Long-term follow-up is necessary in patients with primary malignant lymphoma of the spleen who have been curatively operated because the malignant lymphoma of the spleen may in fact be a metastatic lesion from nodal and extranodal lymphomas, or may be a partial lesion from a multicentrically originating lymphoma.

[A case report of primary double cancer of the stomach and choledochus]

We encountered a relatively rare case of primary double cancer arising simultaneously from both the stomach and choledochus in a 72-year-old woman with obstructive jaundice. The patient was admitted to Saiseikai Shigaken Hospital, and was diagnosed as having both early gastric cancer at the lesser curvature of the antrum and cancer of the choledochus. She underwent curative pancreato-duodenectomy with extended gastrectomy. One of the resected tumors was histopathologically diagnosed as a well differentiated, tubular adenocarcinoma of the stomach with invasion reaching as deep as the submucosa. The other tumor was a moderately differentiated, tubular adenocarcinoma of the choledochus with lymph node metastases (hepatic, retroligamentic, paracholedochal, and posterior and superior pancreaticoduodenal lymph nodes). Our review of the literature suggests that the incidence of primary double malignancies is on the increase.

3H-imipramine uptake into rat striatal slices and imipramine-induced 3H-dopamine efflux

The effect of imipramine on spontaneous efflux of radiolabelled dopamine (DA) from slices of rat striatum was examined by a superfusion method. Imipramine at concentrations of 10 - 100 microM enhanced the efflux of DA accumulated in a high-affinity uptake system in a concentration-dependent manner. This efflux of 3H-DA was not affected by conditions (Ca2+-free medium, 100 microM bretylium and 30 microM tetrodotoxin) which inhibited the release of 3H-DA by electrical stimulation. Furthermore, this imipramine-induced 3H-DA efflux was temperature-dependent. The uptake of 3H-imipramine into striatal slices was determined. This uptake was concentration- and temperature-dependent and increased linearly. These results are discussed in relation to the hypothesis that 3H-DA efflux by imipramine is connected with uptake of imipramine.

Central effects of prostaglandin F2 alpha on the cardiovascular system in the rat

Effects on blood pressure and heart rate of prostaglandin (PG) F2 alpha administered into a lateral cerebral ventricle (i.c.v.) were investigated in urethane anesthetized rats. PG F2 alpha at doses ranging from 2.4 to 47.4 micrograms caused dose-dependent pressor and positive chronotropic actions, but did not exert such actions at a dose of 47.4 micrograms in spinal rats. The cardiovascular actions of PG F2 alpha were reduced by intravenous (i.v.) pretreatment with hexamethonium (2 mg/kg). In addition, the pressor action was blocked by phentolamine (5 mg/kg i.v.) and the positive chronotropic action by propranolol (0.2 mg/kg i.v.). PG F2 alpha (47.4 micrograms) and norepinephrine (2 micrograms/kg) injected i.v. induced transient pressor and positive chronotropic actions. This pressor action of norepinephrine was almost completely eliminated but that of PG F2 alpha was only partially inhibited by phentolamine (5 mg/kg i.v.), while the positive chronotropic actions were unaffected. The results suggest that PG F2 alpha accelerates the cardiovascular functions by stimulating the peripheral sympathetic tone through its central action.

A suprasellar embryonal carcinoma producing alpha-fetoprotein and human chorionic gonadotropin; treated with combined chemotherapy followed by radiotherapy

A case of primary suprasellar embryonal carcinoma that produced alpha-fetoprotein and human chorionic gonadotropin in a 12-year-old girl is reported. Partial removal of the tumor and cis-platinum-based combined chemotherapy followed by local radiotherapy resulted in a definite regression of the tumor and improvement from clinical signs and symptoms. After these treatments, the concentrations of alpha-fetoprotein and human chorionic gonadotropin in both serum and cerebrospinal fluid decreased to undetectable levels. Serum basic fetoprotein, another tumor marker, can be a tool for evaluating the clinical course following postoperative chemotherapy.

Diatrizoate distribution in dogs as a function of administration rate and time following intravenous injection

In this study, we determined diatrizoate concentrations in plasma and the extravascular space in dogs following an injection of the same dose of diatrizoate under three different conditions: (A) subsequent to a rapid bolus injection of diatrizoate: (B) subsequent to a bolus injection followed by an intravenous drip infusion; and (C) subsequent to a slow intravenous drip infusion. The data indicate that the highest plasma level occurred immediately after bolus injection (A). Significantly more diatrizoate was present in plasma 10 to 25 min from the start of an intravenous drip infusion given over 12.5 min (C) than when the same dose was given as a rapid bolus (A). The slow infusion method also resulted in significantly higher diatrizoate plasma levels from 15 to 25 min when compared to the bolus plus drip method (B). The differences in the calculated extravascular concentrations were insignificant among the three groups once all of the contrast material had been infused, i.e., after 12.5 min. The results are discussed in terms of their practical application to cranial computed tomography.

Hepatomas seen on follow-up angiograms in patients with liver cirrhosis

Four cases of hepatoma seen on follow-up angiograms of patients with liver cirrhosis are described. Hepatic angiography is the most useful method of detecting a hepatoma complicating liver cirrhosis, and it should be repeated following any minimal change in the serum alpha-fetoprotein level or when the radionuclide image suggests hepatoma, since a small hepatoma may be resectable.

Benign duodenocolic fistula due to duodenal diverticulum: report of two cases

Two cases of benign duodenocolic fistula resulting from duodenal diverticula are presented. In both cases, the diverticula were located on the outer border of the second portion of the duodenum. The upper gastrointestinal study is the easiest and most useful examination for diagnosis. Hypotonic duodenography and the barium enema complement the upper series and serve to differentiate benign from malignant fistulas.

Intra-aortic oxygen distribution during veno-arterial bypass (VAB) without oxygenation in circulatory assist

Right atrium-femoral artery VAB without oxygenation was performed in 7 dogs at 3 different bypass ratios, 15% 30%, and 45%. Respiration and cardiac output were controlled. Precise intra-aortic distributions of PO2 and O2 saturation were determined by means of a PO2 catheter probe and an oxygen analyzer. The following was concluded: 1) The blood pumped from dog heart produced a narrow "mixing zone" in the mid-aorta with the blood pumped from VAB. The area of the "mixing zone" was in the distal half between renal artery and bifurcation at 15% bypass ratio, in the proximal half between renal artery and bifurcation at 30% bypass ratio, and from celiac artery to below renal artery at 45% bypass ratio. It shifted proximally as the bypass ratio increased. 2) In order to supply necessary oxygen to abdominal viscera, it is recommended that the bypass flow should not exceed 30% of the baseline cardiac output.

Rapid induction of alpha-amylase by nongrowing mycelia of Aspergillus oryzae

A rapid induction system for synthesis of alpha-amylase by the funga Aspergillus oryzae M-13 was established. The mycelia were prepared from 20-h cultures grown on a peptone-glycerol medium and starved for 5 h; maltose was the optimum inducer tested. During h 1 of induction, formation of both intra- and extracellular alpha-amylases occurred at an almost identical rate (70 to 80 microgram/g of cells-h) without a detectable lag period. After a 1-h induction period, a remarkable increase in the extracellular concentration of the enzyme occurred, and a maximum rate (330 microgram/g of cells-h) was reached after 1.5 h of induction. During h 2 of induction, no significant change in mycelial weight was observed. Purified samples of intra- and extracellular enzymes formed in the induction system showed identical properties as examined by behavior in diethylaminoethyl-cellulose column chromatography, gel filtration, discontinuous gel electrophoresis, electrofocusing, optimal conditions for the reaction, heat stability, and molecular weight.

A possible mode of cardiovascular actions of dopamine in dogs

A possible mode of cardiovascular actions of dopamine was studied using ephedrine. In the dog pretreated with repeated administrations of ephedrine (total dose, 40 or 80 mg/kg, i.v.) or with combined administrations of ephedrine (total dose, 90 mg/kg, s.c. and i.v.) and reserpine (2 mg/kg, s.c., 24 hr previously), pressor responses to dopamine were eliminated and reversed to depressor responses whereas depressor responses to dopamine were potentiated. Positive chronotropic effects of dopamine were almost eliminated. Pressor and positive chronotropic effects of tyramine were almost abolished. Sympathomimetic effect of noradrenaline and adrenaline were potentiated while those of isoprenaline were inhibited. In the heart-lung preparation of ephedrine-treated dogs (total dose, 40 mg/kg, i.v.), cardiac stimulating effects of dopamine and tyramine were strongly depressed, and those of noradrenaline, adrenaline and isoprenaline were reduced to some extent. In the open-chest dogs, after pretreatment of cocaine (4 mg/kg, i.v.), pressor, positive inotropic and chronotropic effects of noradrenaline were potentiated, whilst those of tyramine were inhibited. Those of dopamine were not visibly altered, but depressor, negative chronotropic and inotropic effects of dopamine appeared at small doses. In the ephedrine-pretreated dogs, these sympathomimetic effects of dopamine and tyramine after cocaine were strongly depressed and those of noradrenaline were inhibited to a certain degree. The results obtained with ephedrine suggest that dopamine differs from other catecholamines and tyramine in the mode of cardiovascular actions.

[Central effects of clonazepam]

The effects of oral administration of clonazepam, a new benzodiazepine derivative (F. Hoffmann-La Roche), on the central nervous system were compared with those of diazepam and several anticonvulsants in mice and rats. 1) Clonazepam exhibited a moderate inhibitory effect on the locomotor activity observed with open-field situation in mice and no effect in rats, while it inhibited markedly the rearing behavior in both animals, the duration of action being approximately six hours. 2) Clonazepam potentiated the methamphetamine-induced hyper-locomotor activity in mice whereas trimethadione had no effect. 3) Clonazepam inhibited with a moderate potency the conditioned avoidance response and response to a fixed-ratio (FR 20) schedule of food reinforcement in rats, the potency being a little weaker than that of diazepam. 4) The muscle relaxant effect of clonazepam determined by the traction test was slightly more potent as compared with that of diazepam. Thiopental hypnosis was markedly potentiated after clonazepam. 5) The clonic (CL), tonic-flexor (TF) and extensor convulsions (TE) induced by pentetrazol were strongly inhibited after clonazepam in mice, anticonvulsant potency against CL and TE of clonazepam being approximately 23 and 21 times stronger than that of diazepam, 3333 and 3846 times that of trimethadione, and over 3047 and 178 times that of phenytoin, respectively. Clonazepam reduced markedly CL and TE elicited by bemegride with about 12 to 14 times stronger potency than diazepam. On the contrary, the anticonvulsant effect of clonazepam against TE of maximal electroshock seizure evoked by supramaximal current was weak, the potency being 0.71 times weaker than that of phenacemide, 0.14 times than phenytoin and 0.24 times than phenobarbital. By the combined administration of clonazepam with other anticonvulsants such as trimethadione and phenytoin against pentetrazol convulsion, and phenacemide, phenytoin and phenobarbital against maximal electroshock seizure, the antagonistic effect of these anticonvulsants was potentiated by 4 to 5 times. 6) The acute toxicity (LD50) of clonazepam was weak but that of phenacemide or phenytoin was potentiated to a certain degree by combined administration with clonazepam. The results suggest that clonazepam has a psychopharmacological profile similar to that of benzodiazepines with a particularly potent anticonvulsant effect on pentetrazol and bemegride convulsions, and the anticonvulsant effect is synergic with that of other anticonvulsants.

Sympathomimetic actions of reserpine administered during treatment with dopamine in the dog

Reserpine injected intravenously during infusion with dopamine brought about sympathomimetic effects, but a second injection of reserpine after 120 minutes did not elicit such effects. This pressor effect was eliminated by phenoxybenzamine and this positive chronotrpic effect by propranolol. Reserpine induced similar but weak sympathomimetic effects after cocaine, while it induced no changes in blood pressure and heart rate after infusion with noradrenaline. Meanwhile, pressor response to dopamine was potentiated 24 hours after reserpine and was further potentiated after additional infusion with noradrenaline. The sympathomimetic actions induced by the concurrent administration of reserpine and dopamine may be attributable to a facilitation of those indirect mechanisms, prinicpally of endogenous catecholamine release.

Modifications by lithium of behavioral responses to methamphetamine and tetrabenazine

Different groups of mice were injected s.c. daily with lithium chloride in three doses(0.52, 1.58 and 4.72meg/kg) or with saline for a period of 3 weeks. Lithium administered acutely or chronically did not affect spontaneous locomotor activities. However, methamphetamine-induced hyper-locomotor activities were inhibited in the lithium groups as compared with those in the saline group, while the hyper-locomotor activities induced by tetrabenazine in the nialamide-pretreated animals were reduced to some extent but not significantly by lithium. Tetrabenazine brought about an initial transient increase followed by a decrease of spontaneous locomotor activities in the lithium groups, whereas it induced only a decrease of the activities in the saline group. In addition, jumping and vertical jumping behaviors, which were not observed in the saline group, occurred 30-60 min after tetrabenazine in the lithium groups. These effects of lithium tended to increase with an increase of the doses administered and with a prolongation of its daily administration. The results demonstrate that lithium modifies behavioral responses to methamphetamine and tetrabenazine.

Studies Relating to Aziridine Antitumor Antibiotics. Part I. Asymmetric Syntheses. Part II. Chiral Aziridines and their Conversion to α-Aminoacids

Separable diastereomeric cis-l-menthyl 2-phenyl-3-aziridinecarboxylates (4 and 5) were prepared by the Gabriel reaction. N-Acylation with p-nitrobenzoyl chloride or p-anisoyl chloride of 4 and 5 gives 7 and 8, and 23 and 24, respectively. Sodium iodide-catalyzed rearrangement of the N-acylated aziridines is regiospecific with exclusive attack at C-2 and from 8 is obtained the chiral 2-oxazolines cis-9 and trans-10 in a ratio of 30:70 together with the unsaturated amide 11. The structure of the latter was proven by independent synthesis. The intermediate l-menthyl N-p-nitrobenzoyl-3-iodophenyl-alaninate (18) was isolated at lower temperatures and shown to form the equilibrium mixture of 9 and 10 with triethylamine owing to partial racemization by a Finkelstein identity reaction. Use of an N-p-anisoyl substituent in the aziridine improves the yield of chiral 2-oxazolines by preventing the formation of 11, and allows the separation of pure cis- and trans-oxazolines for characterization. The aziridines bearing N-p-anisoyl substituents display a greater sensitivity to attack by weaker nucleophiles than the p-N-nitrobenzoyl analogs.Acid hydrolysis of 9 and 10 gives D-allo-β-phenylserine in an optical yield of about 17% from which 5 and 8 are tentatively assigned the 2R,3R configuration. Similar acid hydrolysis of the 2-p-anisyl-2-oxazoline (26b) allowed the isolation of the intermediate l-menthyl O-anisoyl-allo-β-phenylserinate (30a), hydrolysis of which gave D-allo-β-phenylserine in about 18% optical yield. The isolation of allo-β-phenylserine only from cis- and trans-2-oxazolines is attributed to acid-catalyzed inversion at the benzylic center to the conformationally more stable allo form.

Complement titration by rectilinear attenuance and attempts at its automatization

Immune haemolysis was determined by rectilinear attenuance at 625 mμ (l = 1.3 mm, 1.25 mm), and the data obtained treated by von Krogh's empirical equation. The C′H₅₀/ml values obtained by the attenuance method had high correlation with those obtained by the conventional photometric method (541 mμ).

Automatic complement titration was attempted, as a part of the basic studies on quantitative complement fixation tests.