Evaluation of stricture formation as a complication of vasopuncture and vasography in the guinea pig

Stricture formation at the site of injection for vasography has been observed clinically. An animal model was developed to evaluate this occurrence. Bilateral vasopuncture with a 25-gauge needle was carried out in 25 male guinea pigs. The sites of vas punture were marked with tantalum clips in the perivasal tissue. The left-sided vasa were injected with contrast material and the right sides with normal saline. These 50 vasa were evaluated for radiographic and histologic evidence of inflammation and stenosis 3 months following injection. Ninety-four per cent of the 50 vasa studied showed no significant stenosis. Those vasa exhibiting obstruction were in the first four animals studied, with no correlation as to which material was injected. This finding implicates technical factors as a cause for these results. In the guinea pig, vasopuncture with a fine-gauge needle and meticulous technique does not result in a significant rate of stenosis regardless of the medium injected.

Testosterone rebound therapy: a neglected modality

A summary of the literature and a 20-year review of our own experience with testosterone rebound therapy is presented. Of 225 patients followed, 52% rebounded to fertile levels followed by pregnancy in the wives of 25%. Pregnancy occurred in 3 wives (8%) of the 38 initially azoospermic patients. There was only a 4% incidence of failure to return to at least the pretreatment sperm count following therapy, and no persistent azoospermia was observed. These results are consistent with other recent reports of several large series of patients. Proper screening and selection of patients is mandatory. Testosterone rebound is a neglected form of therapy meriting consideration in selected patients.

Casualty evacuation in the Rhodesian terrorist war

The involvement of the Rhodesian Medical Association in providing medical services to both the troops and the African clinics because of the terrorist war is described. Experiences in the handling and evacuation of casualties by air or road are described, and immediate emergency measures are mentioned. Measures taken to meet a possible escalation of the conflict are reported.

Receptor distribution and the mechanism of enhanced erythrocyte agglutination by soybean agglutinin

We have examined the role of receptor clustering in intact erythrocyte membranes exhibiting enhanced lectin-mediated cell agglutination by analyzing freeze-fracture and freeze-etch images of human erythrocytes labeled with ferritin-conjugated soybean agglutinin. We find that trypsinization and fixation of intact erythrocytes, in either order, causes no alteration of the random distribution of ferritin-conjugated soybean agglutinin on the surfaces of these cells as compared to their distribution on the surfaces of fixed erythrocytes and untreated erythrocyte ghosts. Furthermore, clustering of the intramembranous particles in the membrane of intact erythrocytes was not found with any of the cells described above. We conclude that clustering of the soybean agglutinin receptors is not a major factor involved in the enhanced agglutination of intact trypsinized erythrocytes. Caution is necessary in transferring information obtained with erythrocyte ghosts, where clustering can be induced, to intact erythrocytes.

The nature of alkylurea and urea denaturation of alpha-chymotrypsinogen

The optical rotatory dispersion of alpha-chymotrypsinogen in aqueous solution became less levorotatory upon the addition of ethyl-, propyl-, or butylurea; less negative values for the Moffitt-Yang parameter, alphao, were also obatined. This change in optical rotation of alpha-chymotrypsinogen induced by the alkylureas was similar in direction and magnitude to that observed for alcohols but was opposite to that caused by unsubstituted urea. It appears, therefore, that the alkylureas share with the alcohols an ability to rearrange alpha-chymotrypsinogen into a non-native yet regularly ordered conformation. The effectiveness of the alkylureas and alcohols as denaturants for this protein increased in the order ethyl less than propyl less than butyl derivatives. An identical rank-order was observed for the ability of the alkylureas and alcohols to diminish attractive forces between aliphatic groups, as measured by a model system based upon the extent of aggregation of glass beads coated with methyl groups. These findings indicate that the denaturing action of alkylureas for alpha-chymotrypsinogen is a function of the substituted aliphatic group and is predominantly hydrophobic in character. Non-hydrophobic interactions of unsubstituted urea with alpha-chymotrypsinogen appear to be critical for unfolding of the protein to a random-coil configuration.

Cell rigidity: Effect on concanavalin A-mediated agglutinability of fibroblasts after fixation

A quantitative hemadsorption assay distinguishes the effects of membrane fixation on concanavalin A-mediated agglutinability of fixed cells with unfixed cells. We observed undiminished adherence of unfixed erythrocytes to glutaraldehyde-fixed normal and virus-transformed hamster fibroblasts coated with concanavalin A. Fixation of the erythrocytes abolished agglutination with fixed fibroblasts. The agglutinability of fixed cells is more likely related to increased cell rigidity than to decreased membrane fluidity.

Infertility practice and Orthodox Jewish law

The evaluation and management of infertility problems in Orthodox Jewish couples can be made difficult because of restrictions which may be imposed by religious rules. The origins of the religious laws governing problems such as semen collection, diagnostic and therapeutic genital surgery, menstruation, and homologous and donor insemination are reviewed. Contemporary Rabbinic authorities are quoted; their opinions may serve as guidelines for the patient and physician dealing with infertility problems.

Small-Carrion penile prosthesis. New implant for management of impotence

The etiology of impotence and a review of various techniques in treatment are discussed. A perineal surgical approach with a new type of paired sponge-filled silicone prostheses is described. The prostheses are inserted into previously dilated corpora cavernosa. Of the initial 31 patients, excellent results were obtained 27, and a good result in 1. Of the 3 patients with initial serious complications, adequate functional results were attained in 2. The distinct advantages and potential complications using the Small-Carrion penile prosthesis and surgical technique are discussed.

Auditory delayed matching in the bottlenose dolphin

A bottlenose dolphin, already highly proficient in two-choice auditory discriminations, was trained over a nine-day period on auditory delayed matching-to-sample and then tested on 346 unique matching problems, as a function of the delay between the sample and test sounds. Each problem used new sounds and was from five to 10 trials long, with the same sound used as the sample for all trials of a problem. At each trial, the sample was projected underwater for 2.5 sec, followed by a delay and then by a sequence of two 2.5-sec duration test sounds. One of the test sounds matched the sample and was randomly first or second in the sequence, and randomly appeared at either a left or right speaker. Responses to the locus of the matching test sound were reinforced. Over nine, varying-sized blocks of problems, the longest delay of a set of delays in a block was progressively increased from 15 sec initially to a final value of 120 sec. There was a progressive increase across the early blocks in the percentage of correct Trial 1 responses. A ceiling-level of 100% correct responses was then attained over the final six blocks, during which there were 169 successive Trial 1 responses bracketed by two Trial 1 errors (at 24- and 120-sec delays). Performance on trials beyond the first followed a similar trend. Finally, when the sample duration was decreased to 0.2 sec or less, matching performance on Trial 1 of new problems dropped to chance levels.