Eduardo Zappi

Immunologic consequences of vasectomy.

Abstract A group of men who had vasectomy for contraceptive purposes were available as a model to study the in situ autoantigenicity of human spermatozoa. Bleedings were obtained before, and at several intervals after, the surgery, and the sera were analyzed for spermagglutinins by the Kibrick method. Titers were measured, considering a minimum of 1:8 as positive. Most titers were moderate, although one was 1:1024. A positive result was found in approximately 55% of the 22 cases. The activity generally appeared about 3 to 6 months after surgery, although in some cases, it developed later. Apparently, two patterns of time-response may occur. Three men had pre-vasectomy antibodies to sperm, but in two of these, the titers increased after the operation.

Cryo-immunization. The cold propagation in the target tissue and the resulting volume of the lesion.

Abstract The factors influencing the effectiveness of destructive cryosurgical techniques are reviewed. From thermal measurements performed during cooling-rewarming procedures on living experimental models, predictions are made of the volume that the lesions will have. Attempts to correlate these predictions with macroscopic damage observed with the help of vital dyeing techniques are also made. Finally, the usefulness of such freezing-damaging techniques in cryo-immunology is exemplified.

Cerebral Intraventricular Lipoma and Sudden Death

A lipoma in the left lateral cerebral ventricle of a 73-year-old male is reported. This rather infrequently occurring lesion was an incidental finding in the patients postmortem examination and probably accounted for the acute hydrocephalus that lead to his sudden death.

Histopathology of cryo-injury in rabbit testis

Abstract The histopathologic features of the cryolesion in the rabbit testis have been studied in a group of 15 adult animals, killed 1.2, and 4 weeks after focal freezing on their right testis had been performed. The freezing injury produces a coagulation necrosis in the target parenchyma, and transitory histopathologic inflammatory and degenerative changes of variable intensity in the rest of the gland. A subsequent fibrotic replacement of the necrosed structures occurs, which is achieved about 1 month after the lesion was inflicted. In addition to these microscopic features, which correspond to a general inflammatory and fibrotic process, panarteritis of small-sized vessels and infiltrates of lymphocytes and of eosinophil polynuclear cells were noticed in the nonfrozen testis parenchyma, in the earlier stages of the lesion. The presence of these elements would suggest the existence of an autoantigenic component in the phenomenon triggered by the cryo-injury in the frozen testis of the rabbit. Nevertheless, the high incidence of parasitosis in the rabbits should also be kept in mind as a factor eventually responsible for some of the histologic changes observed around the cryolesion.

Disseminated Cryptococcosis and Sudden Death Report of an Autopsy Case

We report a case of sudden death due to terminal cryptococcal pneumonia in a patient not suspected to have AIDS. The correct diagnosis was found only by microscopic examination and serologic workup, illustrating the hazards faced by forensic pathologists and their assistants working without adequate information about the bodies under study. This case illustrates the need for the highest levels of caution and compliance with universal precautionary measures during autopsy procedures in the present days of the AIDS epidemic.

“Freezing artifacts” in human tissue samples: Their formation and prevention

Abstract The mechanism underlying the formation of the so-called “freezing artifacts” in biopsies exposed to low outdoor temperatures is discussed. Assuming that this mechanism primarily consists of osmotic damage derived from ice formation in the fixative solution in which the biopsies are customarily dispensed (rather than of actual freezing of the samples as it is currently assumed), a 70/30 (v/v) buffered neutral formalin/methanol mixture was developed, which can be held for 15 hr at −20 °C without ice development. This mixture, whose fixative properties are for practical purposes similar to those of regular buffered neutral formalin, used as a substitute for the latter fixative medium, suppressed the expected incidence of about 1–3% cases of freezing artifacts among the several thousand biopsies processed in this laboratory during the winter months of 1979/1980.

Inflammatory Cutaneous Lesions

The inflammatory lesions of the skin may be solitary and constitute by themselves the whole diagnostic problem faced by the microscopist. On the contrary, they may be multiple, representing part of a cutaneous disease or of a systemic condition involving several organs, including the skin.

Elements of Cutaneous Embryology, Anatomy, and Biochemistry

The youngest human embryos in which cutaneous development was observed were about 4–5 weeks old. At that point, the embryo’s external surface is covered by the ectoderm, a monolayer of cells stretching over a mesenchymal mantle. It is partially overlaid by the “periderm,” a second layer of bulky elements endowed with microvilli. This situation and ensuing events are presented in Fig. 1.1.

Proliferative Cutaneous Lesions

The integrants of the division of proliferative cutaneous lesions may be distributed into two subdivisions following their primary reactive or neoplastic nature (Fig. 6.1).

Classification of Cutaneous Lesions

The adjective “cutaneous” hereby refers to the skin and external mucosae, to its adnexa, and to the subcutaneous panniculus. Cutaneous lesions are those that involve the mentioned elements, although they may also comprise cartilage, salivary glands, synovial remnants, and even other elements which may appear incidentally on the external surface of the body. The classification of these lesions would be highly desirable in order to approach the study of dermatopathology in a rational way. However, given the frequently poorly defined histopathologic character of the cutaneous lesion, their often mixed and overlapping features, and, furthermore, the continuous change of the lesions throughout their evolution, that classification may turn out to be a difficult task.