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To determine the effects of castration and testosterone replacement on sperm number in the cauda epididymides 35 hamsters were castrated after bilateral ligation of the corpus epididymides and unilateral vasectomy. Complete isolation of the cauda epididymides for 35 days in "ligated control" or castrated animals prevented the loss of spermatozoa from the region if the ductus deferens remained open. Sperm number decreased 60% 7 days after castration if both the corpus epididymides and ductus deferens were ligated. The method by which spermatozoa are removed from the cauda epididymides depends on whether circulating androgen is present. In the presence of testosterone spermatozoa are not removed in the cauda epididymides but pass into the ductus deferens.

The dosage of testosterone, dehydroepiandrosterone, and progesterone to maintain normal fertilizing capacity of epididymal spermatozoa for 12 days after castration was compared in hamsters. Fertilitytrialsconlirmed previous findings that hamster epididymal spenus are infertile 12 days after castration,in the present study, 12 daily consecutive injections of 100 �tg of testosterone maintained normal fertilizing capacity, but 1 mg daily of its precursor dehydroepiandrosterone was required to achieve the same response. However, sperms were infertile after 12 daily injections of progesterone (0.25 or 1 Ing). The ability of dehydroepiandrosterone to maintain fertilizing capacity in these experiments is attributed to peripheral cjnversion of dehydroepiandrosterone to testosterone at sites other than the epididymis. Pioneering studies of Benoit (1926) and Moore (1928) established that the maintenance of morphology and function in the epididymis depends on the testis, and that epididymal spermatozoa stay motile for a longer time when one or both testes are present. More recently, circulating testosterone has been shown to be important for sperm maturation in the epididymis of rabbits (Orgebin-Crist et at., 1971) and hamsters (Lubicz-Nawrocki, 1973a). The precise mode of action of testosterone, however, remains unclear. In some species, including the hamster, the epididymis has been claimed to synthesize dehydroepiandrosterone (3�3-hydroxyandrost-5-en17-one) and testosterone in vitro (Hamilton, 1971), and considerable hydroxysteroid dehydrogenase activity has been found in this organ (McGadey et at., 1966). The functional significance of androgen synthesis in the epididymis raises the question of whether production of testosterone by the epididymis observed in vitro also

Male hamsters of known fertility were injected subcutaneously with alpha-chlorohydrin to determine the minimal antifertility dose and to elucidate its site of action. Fertility tests at intervals of 4 days showed that alpha-chlorohydrin (66 mg/kg) induced infertility within 4 days and fertilization did not occur after artificial insemination with spermatozoa from the cauda epididymidis of such animals. Comparable daily treatment produced the same antifertility effect after bilateral ligation of the corpus epididymidis and also in castrated animals given daily treatment (100 mcg/day) with either testosterone 5alpha-dihydrotestosterone or 3alpha-androstanediol. The infertility was not related to deficiency of androgen as judged by the concentration of fructose in the seminal vesicles or to impaired ejaculation.(AUTHORS MODIFIED)

In order to evaluate the influence of circulating androgen on sperm maturation the effects of castration and testosterone replacement on the development of fertilizing ability were studied in 10-week-old male and female hamsters. 25 males were divided into 50 equal groups and given the following treatments: 1) isolation of the cauda epididymis; 2) castration epididymal isolation and treatment with 100 mcg testosterone; 3) vasectomy and ligation of the ductuli efferentes (efferentiectomy); and 4) and 5) castration vasectomy efferentiectomy and treatment with testosterone 12.5 and 100 mcg/day respectively. Eggs were flushed from uterine tubes 36 hours after ovulation and examined by phase-contrast microscopy. The fertilization rate of each male was assessed as the percent of fertilized eggs recovered from 3 females. The fertilizing ability of spermatozoa isolated in the cauda epididymis was low after 20 days in intact hamsters (Group 1) and in castrated animals treated daily with 100 mcg testosterone but remained high if new spermatozoa entered the cauda epididymis. Testosterone is metabolized in the epididymis and the possibility that testosterone metabolites may effect sperm maturation in the lumen of the duct is being tested.

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Es wird gezeigt, das die positiven Lp(a)-Reaktionen sich in stark positive (Lp(a+)) und schwach positive (Lp(as+)) unterteilen lassen. Frequenz bei Gesunden und Kranken, Altersverteilung und Vererbung beider Faktoren werden untersucht.

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SummaryHuman or canine fibrin polymers which are structurally altered by the combined action of plasmin and EACA show an increased resistance to digestion by trypsin, but not to digestion by chymotrypsin. These observations support the concept that EACA inhibition of fibrinolysis is to a variable extent a function of structural changes in the substrate, and that the changes may be related to the susceptibility of lysyl- and arginyl-sites attacked by plasmin and trypsin, but not by chymotrypsin.In plasma, the fibrin modification reactions mediated by plasmin + EACA are analogous to those in purified systems, with quantitative differences resulting from the presence of other inhibitors, and perhaps from earlier gelation of the developing polymers.This complexity of the action of EACA must be taken into account in comparing its effects with those of other inhibitors, which also have variable and non-linear effects related to prevention of autodigestion of plasmin, antagonistic or potentiative combinations of inhibitors, and interference with substrate conversion.

Nonequilibrium pumping tests were performed at two widely separated sites consisting of one pumped and two observation wells each. The wells at both sites bottomed in the same stratigraphie formation; at one site a confined aquifer was tested, at the other the aquifer was unconfined. Data gathered from the tests were analyzed using the methods developed by Theis (1935), Jacob (1946), Chow (1952), and Hantush (1961). Eight separate determinations of transmissibility, permeability, and specific yield were made at each site. At the unconfined site, all eight determinations of permeability and transmissibility fell within nine percent of the mean of these calculated values. Specific yield predictions showed a wider variation, with individual computations differing by up to 55 percent from the mean at the confined site. No one method was found to yield consistently higher or lower values for the computed hydrologic characteristics; rather, the observation well used to make the analysis was found to have a more marked effect on the results obtained. Analysis of the well recovery curves confirmed the existence of local recharge near the test sites, explaining the apparent effect of the use of data from different observation wells on the analysis.

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This paper briefly examines traditional approaches to human reliability and presents a technique which permits the system designer to derive a mutually exclusive and exhaustive set of operator error categories in a man-computer system. These error categories are defined in terms of process failures and provide the system designer with a qualitative index suitable for determining error causes and consequences. The technique is demonstrated, and the utility of the resulting error categories is evaluated in the context of two studies on a military information processing system. The paper concludes with a brief discussion of detectable and non-detectable errors and a suggestion for determining the impact of errors on ultimate system goals.

Five experiments were undertaken to assess individual and team evaluation of the diagnosticity of hypothetical “code-breaking” tests. Three aspects of diagnosticity were examined: P(S), or the probability that a test will be successful (reduce uncertainty as to which “code” is being used) ; reductive capacity, or the amount of uncertainty reduced by a successful test; and redundancy, or the extent to which two tests convey the same information. Experiments I–IV indicated that individual subjects are highly sensitive to all three aspects of diagnosticity. Experiment V revealed that the extent to which redundancy of information between teammates can be resolved depends on team structure. Freely interacting teammates in a decentralized arrangement can solve redundancy as well as individuals; other team arrangements (concocted and centralized) yield poorer performance in this regard. The method utilized in this research seems eminently suited to the study of small groups.

In 21 liver cirrhotics (19 men, 2 women) the urinary excretion ofδ-aminolevulinic acid, porphobilinogen, uro- and coproporphyrin, and hepta-, hexa-, and pentacarboxylic porphyrin was studied. Porphyrins in liver biopsy tissue were also analyzed in 17 of the 21 cases. Only a single patient had slight clinical symptoms of porphyria cutanea tarda.

SUMMARY The effects of testosterone, dihydrotestosterone, 3α- and 3β-androstanediol on the fertilizing capacity of mature epididymal spermatozoa and on the production of fructose by the seminal vesicles were compared in golden hamsters. When injected subcutaneously into castrated animals, 100 μg testosterone, 75 μg dihydrotestosterone but only 12·5 μg 3α-androstanediol per day were required to maintain the fertilizing capacity at the control level for 12 days; 3β-androstanediol failed to maintain the fertilizing capacity of epididymal spermatozoa for 12 days. Although testosterone and dihydrotestosterone were equipotent in stimulating production of fructose by the seminal vesicles, 3α- and 3β-androstanediol were much less effective. The discrepancy in the response of the cauda epididymidis and seminal vesicles to 3α-androstanediol suggests that the hormonal requirements for sperm survival in the cauda epididymidis differ from those for the production of fructose in seminal vesicles. The results suggest that circulating testosterone may be relatively inactive in the cauda epididymidis and that the maintenance of fertilizing capacity of epididymal spermatozoa might be correlated with the reduction of dihydrotestosterone to the more potent androgen 3α-androstanediol by mature spermatozoa.