Richard J. Blandau

Proteolytic Reaction of Mammalian Spermatozoa on Gelatin Membranes

The acrosomes of spermatozoa of several mammalian species show proteolytic activity when applied to fixed gelatin membranes. The technique permits continuous observation of the enzymatic reaction of an individual spermatozoon. Release of the enzyme occurs solely in the region of the acrosome, in a manner which is species-specific.

MECHANISMS OF TUMOR HOMOGRAFT REJECTION: THE BEHAVIOR OF SARCOMA I ASCITES TUMOR IN THE A/JAX AND THE C57BL/6K MOUSE*

The respective roles that classical humoral antibodies and hypothetical “cellassociated” antibodies may play in tumor homograft rejection and the mechanisms by which they act remain major unsolved problems in homograft immunity. Whereas classical humoral antibodies to tumor homografts are commonly produced, their participation in tumor rejection has been clearly demonstrated only in a limited number of tumor-host combinations. Tumors derived from cells of the lymphoid series appear to be particularly susceptible to in vivo destruction by humoral antibody. Excellent discussions of the evidence bearing on the problem of the mechanisms of tumor homograft rejection have been presented recently by Gorer,’ Amos: and Snell and co-~orkers .~ The purpose of the present investigation is to gain further information about the mechanisms by which cell-associated antibody factor of immune host cells may accomplish the destruction of tumor cell homografts. The system, Sarcoma I (Sa I) in the C57BL/6K mouse, was chosen because it is one in which homograft rejection appears to depend solely on cell-associated antibody. Indeed, in this system classical humoral antibody exerts a suppressive rather than an augmentative effect on tumor rejection and induces an “immunological enhancement” of tumor growth rather than i m m ~ n i t y . ~ Sarcoma I originated in 1947 in a mouse of the Strong A strain that had been treated with dibenzanthracene. The tumor grows progressively in the A/ Jax subline of the Strong A mouse and kills 100 per cent of the animals. In contrast, mice of the resistant C57BL/6K strain, given a standard dose of 30 million ascites tumor cells by the intraperitoneal route, reject the tumor in essentially 100 per cent of the cases. The tumor shows unrestricted growth in the animals until the 6th or 7th day, when rejection begins. Rejection is largely completed by the 8th day, and the animals remain immune to rechallenge for weeks thereafter. Since our preliminary attempts failed to demonstrate that Sa I cells are destroyed by reaction in vitru with immune cells, attention was centered on in vizw studies of interaction between immune host cells and tumor cells. If the rejection of Sa I by the C57BL/6K mouse results from contact of immune

Studies on the mucosa of postmenopausal oviducts: surface appearance ciliary activity and the effect of estrogen treatment.

The epithelial lining of the human oviduct is known to be responsive to the fluctuating hormonal levels of the normal menstrual cycle, but its response to the changes in hormonal climate at the time of the menopause is not clearly defined. In this study the oviducts of nine postmenopausal patients were obtained at the time of abdominal hysterectomy, and the lining epithelium was studied by scanning electron microscopy. The activity of cilia on the fresh tissue was assessed by their ability to transport particulate matter applied to the epithelial surface. The fimbriae of oviducts from women who had received little or no estrogen treatment before surgery showed a significant deciliation of the epithelium, compared with specimens from premenopausal patients, and even showed some sloughing of cells from the surface. The secretory cells appeared inactive. However, the specimens from patients who had been treated with estrogen for periods of 1 year or more showed a remarkable maintenance of the epithelium, with the proportion of ciliated cells remaining almost as high as in premenopausal oviducts, even as late as 25 years after the menopause. The ampullar and isthmic portions showed less obvious changes. Cilia in oviducts from the former group (short-term or no treatment) were incapable of transporting 15-mum microspheres or lycopodium spores applied to the epithelial surface, whereas the oviductal cilia obtained from patients under long-term estrogen therapy showed efficient transport of particulate matter. The results are discussed in relation to earlier conflicting reports on the postmenopausal oviduct.

Observations on living oogonia and oocytes from human embryonic and fetal ovaries

This report summarizes a series of observations on human oogonia and oocytes recovered from 22 living human embryos and fetuses with crown-rump lengths of from 22 to 171mm. Fragments from each gonad were examined immediately in specially prepared squash preparations. The remaining gonadal tissues were placed in tissue culture preparations and studied for approximately 80 days. Living human germ cells have the capacity for ameboid movement if examined before they are encompassed by follicular cells. Oogonia arranged in cords or clones have been observed to undergo repeated cell divisions in synchrony. After a number of cell divisions the oogonia stop dividing and enter the prophase of meiosis proceeding to the dictyotene stage. Some of the oocytes in tissue culture grow to diameters of 60 to 80 μ and develop incomplete secondary membranes. Multinucleate oocytes are seen frequently in the younger cultures. Most of them disappear by the fiftieth day in culture. Atresia is a common feature in oocytes growing in tissue culture.

Methods for studying oviductal physiology.

In studying oviductal physiology, it is important to sort out the complex interrelationships between muscle, cilia, nerves and secretory processes as they each of themselves, or in concert, effect gamete transport. In this review, a variety of physiological techniques and bioengineering approaches which have been used to monitor contractile and ciliary activity, are described and critically evaluated.

The Role of Estrogens in Egg Transport Through the Ampullae of Oviducts of Castrate Rabbits

This article presents a description of patterns of muscle activity and ovum transport through the ampullae of the oviducts of 12 sexually mature New Zealand White female ovariectomized rabbits in 3 circumstances: 1) with no hormonal treatment; 2) 1-3 hr. after the last of a series of estrogen injections; 3) 30-32 hr. after the last injection in the series. The estrogen injected was estradiol-17-beta given in portions of 6 mcg. The time required for 89 supravitally stained donor eggs to pass through the ampullae of the oviducts for each of the 3 groups was as follows: 1) 25 ova in 4 castrate rabbits of Group 1 mean transport time 15.2 plus or minus 3.6 min.; 2) Group 2 rabbits 30 ova in 3 rabbits mean transport time 12.0 plus or minus .7 min.; 3) Group 3 rabbits 34 ova in 5 rabbits mean transport time 2.4 plus or minus 1.6 min. The rabbits were castrated for periods ranging from 84-165 days prior to ovum transport observations. The decrease in transport time from Group 1 to Group 3 is associated with an increase in activity of the ampullary musculature. The increase in muscle activity and rate of ovum transport are interpreted as being related in some manner with a reduction in the amount of estrogen present in the estrogen-primed smooth musculature of the ampulla.

An Analysis of the Mechanisms of Egg Transport in the Ampulla of the Rabbit Oviduct

Ampullary transport of supravitally stained cumulus egg masses was studied in intact oviducts of anesthetized rabbits whose abdomens had been opened for observation. Following observations of normal t

An Optoelectronic Instrument for Ovulation Detection in Animals

An optoelectronic instrument for detecting the ovum and its surrounding cumulus mass in the oviductal ampulla of rabbits was successfully tested in the abdominal dish preparation of Blandau. An optical transducer, constructed in the shape of a cuff designed to fit about the oviduct, measures changes in the intensity of light transmitted through it. As a cumulus egg mass passes through the sensor, a large sustained increase in light transmittance is recorded. Since ampullary egg transport follows ovulation within minutes, this instrument may provide a means of accurately determining the time of ovulation.

AN ANALYSIS OF THE MECHANISMS OF EGG TRANSPORT IN THE AMULLA OF THE RABBIT OVIDUCT

Ampullary transport of supravitally stained cumulus egg masses was studied in intact oviducts of anesthetized rabbits whose abdomens had been opened for observation. Following observations of normal transport, muscular activity of the ampulla was inhibited pharmacologically with Acepromazine, a preanesthetic tranquilizer. With muscle contractions blocked, egg transport continued but in a dramatically altered fashion; in the final two thirds of the ampulla the motion changed from rapid to-and-fro movements to a slow uniform prouterine movement which was attributed to ciliary activity. However, the net velocity of transport did not change when the smooth muscle was inhibited indicating that muscle contractions are at least unnecessary and perhaps ineffective for ampullary egg transport in the rabbit.