A new biological assay method for histamine-sensitizing factor using survival time as a response

A new biological assay method using survival time of mice as a graded response after histamine challenge has been developed for the histamine-sensitizing factor of pertussis bacilli. The method is relatively precise and reproducible in estimation and fairly sensitive in the validity tests of biological assay. Effect of endotoxin on the estimation by the proposed method was also investigated in case the method is applied to the control test of pertussis vaccine.

In vitro transfer rate of 14C from acetate-1-14C into ovarian steroids in the rat ovary during the estrous cycle and effects of LH and FSH

Fluctuations of ovarian biosynthetic activity and effects of exogenous LH and FSH on it during the estrous cycle were investigated by measuring in vitro transfer rates of 14C from 14C-1-acetate into progesterone (P), 20 alpha-hydroxy-pregn-4-en-3-one (20 alpha-OH-P) and estrogen (estradiol and estrone, E) in the ovarian homogenates from rats autopsied at 2 hour intervals. The transfer rate of 14C from 14C-1-acetate into P was lowest in the afternoon of estrus and increased from the morning of diestrus 1, making its peaks during the afternoon of diestrus 2 and in the midnight of proestrus. The transfer of 14C into 20 alpha-OH-P was high on the days of diestrus 2 and proestrus with its peak in the afternoon of the latter day. The maximum transfer of 14C into E in the afternoon of proestrus and a high rate in the morning of estrus with relatively low one in the midnight were observed. Exogenously injected LH (150 mug) or FSH (150 mug) was either stimulatory or inhiibitory to the transfer rates of 14C from 14C-1-acetate into ovarian steroids. During day time of diestrus 2 and midnight between proestrus and estrus, the transfer of 14C into P and 20 alpha-OH-P increased by LH, and during day time of proestrus and from the afternoon of estrus to the morning of diestrus 1 decreased. The transfer of 14C into E increased by LH from the afternoon of diestrus 2 to the morning of proestrus, and decreased during the afternoon of proestrus and from the afternoon of estrus to the morning of diestrus 2. Administration of FSH was also stimulatory or inhibitory. The 14C transfer into P and 20 alpha-OH-P increased by FSH from the afternoon of estrus to the morning of proestrus, but in the afternoon of proestrus they decreased. Transfer of 14C into E increased by FSH significantly on the days of diestrus 2 and proestrus, and slightly on the day of estrus, while it decreased in the afternoon of diestrus 1.

Effect of low protein diet on cardiac function and ultrastructure of spontaneously hypertensive rats loaded with sodium chloride

The effects of low protein diet on cardiac metabolic and structural changes subsequent to an extremely high pressure load were investigated. Spontaneously hypertensive rats(SHR) were divided into four groups, and fed the following diets for four weeks: 1) Group A: regular diet (23% protein) and water, 2) Group B: regular diet and 1% saline, 3) Group C: low protein diet (10% protein) and water, and 4) Group D: low protein diet and 1% saline. Two weeks after the start of feeding, there was no significant difference in the left ventricular ultrastructures between the corresponding regular and low protein diet groups. Four weeks after, degenerative findings such as streaming of Z lines, dilatations of smooth endoplasmic reticulum, and disarrangements of myofilaments appeared Group D, while in Group B electron microscopic findings indicated hypertrophy. Incorporation of [14C] leucine into the myocardial myosin B in Group D was significantly low, with a resulting fall of the LVdP/dtmax per integrated isometric pressure (IIP) and a rise of the left ventricular end-diastolic pressure (LVEDP), as compared to that in Group C at four weeks after the start of feeding. These observations suggest that, in the heart with an extremely high pressure load, low protein diet hinders the development of hypertrophy to the load with resulting heart failure.

Studies in meconium: disaccharidase activities in meconium from cystic fibrosis patients and controls

Meconium ileus represents the earliest clinical manifestation of cystic fibrosis. The differences found in the composition and amount of protein, mucoprotein, mucopolysaccharides, and reducing sugars in meconium from newborns with cystic fibrosis might be of significance relative to the pathogenesis and early diagnosis of this disease. We studied the enzymatic activity of disaccharidases (lactase, sucrase, maltase, and palatinase) in meconium of infants with cystic fibrosis and controls. We found an increase in the specific activity of these enzymes in the meconium from infants with cystic fibrosis as compared to the specific activity in meconium from normal infants. The increase in the activities, expressed as micromols per gram of protein per minute was: lactase, 100 times higher; sucrase, 18 times; maltase, 4.8 times, and palatinase, 8.9 times.

Tables for estimating the mean of distribution of logarithms of titers based on data with a pooled serum sample

A table was constructed for use in estimating the mean of distribution of logarithms of titers based on data obtained with a pooled material instead of those with individuals in a sample. A table of standard errors of the estimator was also constructed. Examples showing the utility and applicability of the tables were presented. Several relating problems were discussed.

Toxicities of influenza vaccine: peripheral leukocytic response to live and inactivated influenza viruses in mice

Intraperitoneal or intravenous inoculation of live or inactivated influenza virus induced two characteristic responses of the peripheral leukocytes in mice, an early appearing leukopenic response and late appearing lymphopenia. The former response usually developed and subsided within several hours, though the change in leukocyte population was fairly complicated depending upon the activity of the inoculated material, while the latter began several hours after inoculation and reached its minimum level in 10 to 20 hr. The agent responsible for the former may be virus pyrogen, while the latter seems to be caused by some substance(s) other than that. The early appearing leukopenic response was similar to that due to bacterial endotoxin in respect to the characteristic pattern of the change in peripheral leukocyte population, though it was relatively easy to distinguish one from the other by the length of the latent period and by the heat stability of the causative agent. Live or inactivated influenza virus causing the early appearing leukopenic response was found also to have the mouse body weight-decreasing toxicity. The significance of these findings in the laboratory control test of influenza vaccine for untoward reactions often observed in human inoculated with some inactivated influenza vaccines was discussed. The possible roles of the two agents, virus pyrogen and endotoxin, in the febrile response were mentioned.

An anucleolate mutant of the cellular slime mould Dictyostelium discoideum

Summary: An anucleolate mutant (AN) was isolated from the cellular slime mould, Dictyostelium discoideum. The AN developed normally until the beginning of culmination, when development stopped and no differentiation of the spore or stalk cell occurred. The AN had nucleoli at the vegetative stage, but lost them after formation of a cell mass, in contrast to the wild type (WT) which possessed them throughout development. AN cells disaggregated from a slug, reconstructed nucleoli and resumed vegetative growth. Difference in tetrazolium reduction between the prestalk cell and the pre-spore cell, as observed in the WT, was not detected in the AN, although vacuoles specific to the pre-spore cell were formed. When the WT and AN cells were mixed, they aggregated together, but no interaction in cell differentiation was observed. The roles of nucleoli in the development of this organism are discussed.