Prostatic cryosurgery: use of MR imaging in evaluation of success and technical modifications.

PURPOSE: To evaluate the usefulness of contrast material-enhanced magnetic resonance (MR) imaging in objective assessment of prostatic cryosurgery and the role of MR imaging in the modification of prostatic cryosurgical technique. MATERIALS AND METHODS: Thirty-eight consecutive patients with localized (T1-3, N0, M0) prostatic adenocarcinoma treated with prostatic cryosurgery underwent MR imaging without contrast enhancement before cryosurgery and unenhanced and gadolinium-enhanced MR imaging within 1-3 weeks after cryosurgery. The first 20 patients also underwent MR imaging at 3 months after cryosurgery. MR imaging findings were correlated with those from transrectal ultrasound-directed prostatic staging biopsy. RESULTS: Cryonecrotic prostate was identified as avascular regions characterized by absolute signal void on contrast-enhanced images. With progressive modification of cryosurgical technique, complete cryoablation of the prostate was achieved in the latter nine of the 38 patients. When cryoablation was considered complete according to MR imaging criteria, findings invariably correlated with those at biopsy, with no residual prostate tissue or tumor. CONCLUSION: Gadolinium-enhanced MR imaging of the prostate after cryosurgery provides a highly accurate means of monitoring success. Objective MR imaging findings allow modifications to the technology and technique, resulting in optimal therapeutic results with prostatic cryosurgery.

Growth and development of winter tick, Dermacentor albipictus, on moose, Alces alces.

Moose, Alces alces, were infested with 21,000 or 42,000 larval Dermacentor albipictus at the end of September. Larvae grew rapidly and molted to the nymphal stage 10-22 days after infestation. The nymphal stage lasted approximately 3 mo until mid-January and was characterized by a diapause. The diapause is likely an adaptation to survival in cold climates. Nymphs started engorging in January and adults were seen with increasing abundance from mid-January to March and April. The minimum parasitic period was 175 days. Growth of larvae and nymphs was similar on moose given different numbers of larvae and was generally similar between a moose infested in November and moose infested earlier. Dimensions and stages of development throughout the parasitic phase are given. Game enforcement officers are encouraged to use these data for determination of season of death of moose.

Tick (Dermacentor albipictus)-induced winter hair-loss in captive moose (Alces alces).

Five captive moose calves each infested with 42,000 larval Dermacentor albipictus, six calves each infested with 19,000-21,000, and five control moose were observed for changes in hair-loss, body condition and number, stages, and distribution of the tick. Winter hair-loss was observed only in moose infested with ticks and was correlated positively with the total number of adult ticks. Hair-loss associated with ticks was minimal from October to January, but rapidly increased from February to April when up to 44% of hair had been removed. The pattern of hair-loss was similar in all moose with the neck, shoulders, withers, and perianal areas losing the most hair. Moose with extensive premature hair-loss had less pericardial and abdominal visceral fat than moose with little or no hair-loss.

Bronchial artery distribution in various mammals and in humans.

Marked subgross differences in the distribution of the bronchial artery in 10 mammalian species and in humans were found using thin-slice latex injection preparations. Described are variations in distribution to the pleura, interlobular septums, distal airways, alveoli, and the presence of bronchial artery-pulmonary artery anatomoses. The bronchial artery is considered the nutrient artery to the lung. In general, its distribution seems to depend upon the amount of supportive or non-gas exchanging tissues present, which also varies greatly from species to species. The existence of differences in pathologic, physiologic, and pharmacologic characteristics is implied by these findings as well as the need for caution in selecting laboratory animals if the results are to be applied to humans.

Ultrastructural alterations in collagen associated with microscopic foci of human emphysema.

Postmortem and biopsy lung samples were examined with a dissecting microscope and classified into three categories: no overdistended air spaces visible, mild destruction and some fenestration of the septa with minimal confluence of air spaces, and more advanced breakdown of alveolar walls with at least a sixfold increase in air space to a 1300 mu diameter. Prominent ultrastructural tissue alterations were found within the focal regions where fenestration of the alveolar wall and some confluence of air spaces were identified. Edema and rearrangement of the supportive tissues were noted in the alveolar septa adjacent to foci having the greatest alveolar enlargement. Randomized electron dense collagen fibrils were found only in these areas, whereas the normal alveolar septa contained uniformly parallel collagen fibrils. Many of the randomized fibrils had sufficient swelling to display prominent internal spiraling. Other changes in structure and cell numbers were consistently found in association with the altered collagen. These included: separation of the type I epithelial cells from the basal lamina and some autolysis of the cytoplasmic organelles, numerous flattened type II epithelial cells, and aggregations of pulmonary macrophages.

Idiopathic spontaneous pneumothorax. Electron microscopic study.

A lung biopsy obtained from a patient following a second occurrence of idiopathic spontaneous pneumothorax was studied by electron microscopy. A remarkable increase in septal mass was a notable finding. Proliferation of the interstitium was due to an abundance of collagen and elastic fibers. In additon, a proliferation of type 1 and type 2 epithelial cells was seen.