Myxoma of Oral Soft Tissue

The clinical and histopathologic characteristics of oral soft tissue myxoma are reviewed. A case of soft tissue myxoma of the alveolar ridge is presented, and the diagnosis is discussed.

Teratogenic Effects of the Interaction Acetylsalicylic Acid (ASA) and Ethanol: Morphologic and Morphometric Evaluation of the Lingual Epithelium in Rat Fetuses

The objective of the present work was to evaluate the teratogenic effects of the interaction between acetylsalicylic acid (ASA) and ethanol on the epithelium of the lingual mucosa in rat fetuses. On the 10th pregnancy day, a single intraperitoneal ethanol dose (2.96 g/kg body weight) (Group I), ASA (200 mg/kg body weight) (Group II) and ASA plus ethanol, in the same doses (Group III), or saline (Group IV - control), were administrated. The epithelial alterations were assessed by means of histological and morphometric methods, on posterior dorsal, anterior dorsal and ventral regions of the tongue. ASA reduced, in rat fetuses, the ethanol deleterious effects on nuclear size in the epithelial prickle cell of the lingual mucosa. On the other hand, ASA did not influence the effects of ethanol in both epithelial layers of the lingual mucosa, when the nuclear shape, cell volume or epithelial layers thickness were evaluated.

EMG analysis of the upper and lower fascicles of the orbicularis oris muscle in deaf individuals

The aim of this study was to analyze electromyographically the upper and lower fascicles of the orbicularis oris muscle in deaf patients comparing them with clinically normal patients. These patients present several disorders in facial muscles, temporomandibular joints disorders and constantly headache in virtue of not the use of the face expression muscles. This was performed in 30 patients from both sexes with a mean age of 18.5 years, divided into 3 groups of 10 patients each: 1. deaf patients with buccal breathing and incompetent lips; 2. in deaf patients with nasal breathing and competent lips; 3. clinically normal patients, in 7 clinical conditions: at rest with and without labial contact, sucking water, blowing, pursing and reciprocal compression of the lips and the emission of the syllabi "PA". It was observed that in the deaf patients group, both fascicles of the orbiculares oris muscles presented hyperactivity in most of the analyzed movements, mainly in buccal breathing with incompetent lips, and the lower fascicle demonstrated the highest electromyographic activity.

Electromyographic evaluation of the adductor pollicis muscle of elderly patients carriers of removable partial prosthesis when using acrylic devices adapted to the handle of toothbrush

The aim of this study was to evaluate the muscular activity of the adductor pollicis muscle, by electromyography, when using a device made of acrylic resin adapted to the handle of toothbrush. 10 patients of both sexes from the Clinic of Removable Partial Dentures of the Dental School--USP, with a mean age of 65 years, were selected. Electromyographic records were obtained with patients in clinical conditions of Initial Rest and under conditions of claw apprehension and dental brushing. The mean results obtained, in mV, were: sat men: 2.97 for rest (R); 11.55 for free closure (FC); 35.80 for strained closure (SC); 29.30 for simulated brushing (SB); 55.00 for brushing (B); 26.87 for simulated brushing with the device (SBA); 69.70 for brushing with the device (BA); 3.72 for post exercise rest (PR). Standing: 2.27 for rest (R); 13.92 for free closure (FC); 45.85 for strained closure (SC); 28.40 for simulated brushing (SB); 72.07 for brushing with the device (BA); 1.42 for postexercise rest (PR). Sat women: 9.78 for rest (R); 22.71 for free closure (FC); 41.48 for strained closure (SC); 26.45 for simulated brushing (SB); 52.78 for brushing (B); 17.00 for simulated brushing with the adapter (SBA); 42.38 for brushing with the adapter (BA); 14.40 for postexercise rest (PR). Standing: 5.26 for rest (R); 17.81 for free closure (FC); 46.55 for strained closure (SC); 40.61 for simulated brushing (SB); 61.71 for brushing (B); 26.08 for simulated brushing with the adapter (SBA); 54.06 for brushing with the adapter (BA); 3.46 for postexercise rest (PR). The adductor pollicis muscle showed a higher electromyographic activity, considered statistically similar to each other, in 3 clinical conditions analyzed: brushing (B), brushing with the adapter (BA) and strained closure (SC). The adductor pollicis muscle showed lower electromyographic activity, considered statistically similar, in 5 clinical conditions analyzed: simulated brushing (SB), simulated brushing with the adapter (SBA), free closure (FC), rest (R) and postexercise rest (PR).

Modification of col shape and interproximal area after periodontal surgery associated with the restorative alveolar interface (RAI) technique. Histological study in dogs

The modification of the col shape and position by the restorative alveolar interface technique (RAI) was studied in the interproximal areas between the mandibular first molars and fourth premolars of 10 dogs. Full thickness flaps were raised to expose the interproximal root surface and alveolar bone crest. The RAI procedure was performed only on the experimental sides and the control areas were the opposite side of the same animal. The animals were sacrificed at zero hour, 7, 14, 21 and 28 days for histological analyses. Approximately 6.0-micron-thick sections were made in buccolingual and mesiodistal directions and stained with hematoxylin-eosin and Mallory for light microscopy analysis. A satisfactory healing process was observed up to the 14th and 21st days which showed a modified col shape. At this time, an inflammatory reaction developed affecting the evolution of the healing. The surgery had probably created conditions for the installation of an inflammatory process resulting from the modified anatomy of the interdental area.

EMG activity of the orbicularis oculi muscle in normal and in individuals indicated to receive eye prosthesis, before and after its placement

To analyze comparatively through electromyography (EMG) the orbicularis oculi muscle from normal patients and those indicated to receive eye prosthesis (treated patients), it was studied 24 male patients with a mean age of 32.5 years old, who were divided into 2 groups as follows: 12 individuals with absence of the left eyeball and indicated to receive prosthesis (treated); 12 normal individuals (control). The work was performed in 4 different clinical conditions: initial resting; normal opening and closure of the eyelids; forced opening and closure of the eyelids and final resting, before and after placement of eye prosthesis. The exams were made using an Electromyograph K6-I Light Channel and Surface Electrodes. By the results obtained under the work conditions, we can conclude that: the use of eye prosthesis did not interfere in the clinical conditions of opening and closure of the eyelid; the loss of the eyeball increases the EMG activity of the orbicularis oculi muscle; the use of eye prosthesis for a period of 7 days, was not enough to diminish the muscular activity, even its perfect adaptation been evidenced clinically.

Scanning electron microscopy of the rat tongue mucosa with special attention to the bacteria on epithelial cell membranes

The authors examined the filiform and fungiform papillae surfaces of rat tongue by scanning electron microscopy showing the numerous groupings of bacteria on the epithelial cell membranes. The fungiform papillae were round in shape and present few bacteria. The epithelial cell of filiform papillae revealed numerous streptococci. The grouping of the bacteria are attached on the epithelial cell membrane, demonstrating three-dimensional SEM images.

Latex allergy in health care personnel

This article presents a summary of literature published in recent years about latex allergy. The first article on allergic reactions associated with latex was published in Britain in 1979. Since then, the number of reported cases has increased. A wide variety of allergic reactions that range from contact dermatitis to anaphylactic shock are described in literature. Conclusions support that health care team members must be well informed about the implications of latex allergy to better help allergic individuals.

Identification of a 30 kDa antigen from leishmania (L.) chagasi amastigotes implicated in protective cellular reponses in a murine model

An antigen of apparent molecular mass of 30 kDa, termed p30, was purified from Leishmania (L.) chagasi amastigotes after separation of parasite extracts by sodium dodecyl sulfate-polyacrylamide gel eletroctrophoresis followed by electroelution. The use of the purified antigen in lymphocyte cultures from BALB/c mice previously immunised with L. (L.) chagasi amastigotes led to high levels of proliferation. Animal immunisation with p30 plus complete Freund's adjuvant either by subcutaneous or intraperitoneal route led to comparable antigenic stimulation. Similar stimulation indices induced by p30 were also obtained when animals were immunised with Corynebacterium parvum as adjuvant by the intraperitoneal route. Detection of IL-2 and IFN-gamma in the supernatants from lymphocytes stimulated by p30 and inhibition of the production of these lymphokines in the presence of anti-CD4 strongly indicated the involvement of the Th1 subset in the responses elicited by p30 antigen. Immunisation of BALB/c mice with p30 provided partial protection against challenge with L. (L.) chagasi amastigotes, indicating a protective role for p30 and that Th1 can be related to accquired resistance to visceral leishmaniasis in a murine model. Further characterisation studies were performed by the use of a monoclonal antibody directed to a cysteine proteinase of 30 kDa from L. (L.) amazonensis amastigotes. Despite the cross-reactivity presented by p30 from both Leishmania species, the p30 from L. (L.) chagasi amastigotes lacks proteolytic activity.

Denture-induced fibrous inflammatory hyperplasia: a retrospective study in a school of dentistry

PURPOSE

The aim of this study was to investigate the denture-induced fibrous inflammatory hyperplasia (FIH) that occurs around the borders of an ill-fitting denture, in relation to frequency of the lesion, age and sex distribution, length of denture use, and frequency of dysplasia.

MATERIALS AND METHODS

A comprehensive review of FIH diagnosed in patients wearing dentures by the oral pathology diagnostic service at the University of São Paulo over 26 years (1971 to 1996) was undertaken, based on retrospective analysis of the oral histopathologic files.

RESULTS

The frequency of FIH was 15% of the total number of pathologies diagnosed at the service of oral pathology in that period. The disorder occurred predominantly in the fifth and sixth decades of life and more often among females, at a proportion of 5:1. The frequency of FIH was higher for a length of denture use of between 1 and 10 years. Dysplasia was found in 4% of cases.

CONCLUSION

The knowledge of some aspects of FIH, especially the possible histologic alteration of dysplasia, supports the importance of the diagnosis and treatment of the lesion and suggests that any excised tissue should be submitted to histopathologic evaluation. Education and regular review of patients who have worn dentures are essential if the development of FIH is to be prevented.

Angioarchitectural arrangements in corrosion cast of the nasal septum of the Mongolian gerbil

The three-dimensional architecture of the vascular network of the nasal septum of the gerbil rat was studied using the corrosive resin cast technique. The angioarchitecture of the nasal septum observed with scanning electron microscopy (SEM) showed that a vascular network is disposed in the lamina propria. The capillaries, arterioles, venules and arteries were closely observed in different areas of the nasal septum mucosa.

[Allergic reactions caused by latex: warning to health workers]

In this study, a bibliographic survey is made of all articles, published during the last few years, dealing with allergic reactions to latex. The first article on allergic reactions associated with latex was published in Britain, in 1979. Since then, the number of cases reported have increased (Barton, 1993). Type I allergic reaction (immediate reaction) and Type IV (delayed reaction) are part of the latex allergic process (Steelman, 1995). Contact allergy is due to inadequate washing during manufacture, which results in the retention of water-soluble proteins that cause allergic reactions in susceptible people. A wide variety of allergic reactions that vary from contact dermatitis to anaphylatic shock are described in literature. These finding show that a health team must know the probable implications of latex allergy.

The annual testicular cycle of the domestic quail (Coturnix coturnix japonica)

A morphometric study was conducted on the testis of the domestic quail Coturnix coturnix japonica to determine testicular kinetics. We investigated the variability along the year of testicular parameters such as seminiferous tubule diameter, germinal epithelium height and amount of meiotic figures of maturing spermatids in the seminiferous epithelium and of sperm in the tubular lumen. The results of morphometric analysis showed the occurrence of an annual testicular cycle defined by four distinct phases: a resting phase (at the end of summer), a recrudescence phase (in the fall), a proliferative phase (at the end of winter and beginning of spring), and a regression phase (spring and summer). We also observed that the testes of adult quails present elevated and maximal spermatogenic activity in fall-winter (short-day period) and at the beginning of spring, respectively, and lower values in spring and summer (long-day periods), with minimum values at the end of summer.

[The most frequent nursing diagnoses in an oncology admission unit]

The aim of this paper was to survey the most frequent nursing diagnoses by means of the nursing history and medical procedure in order to help the care provided at the Oncology Nursing Service of Women Health Whole Care (Centro de Atenção Integral à Saúde da Mulher-CAISM). The five most common diagnoses were: risk for infection, risk for altered body temperature, risk for aspiration and colonic constipation of the exchanging pattern, and risk for activity intolerance of the moving pattern. Data collection was based on these patterns. Data predominantly involving social, cultural, psychological and spiritual aspects were hardly interpreted, because they were poorly registered or omitted.

Biochemical and histopathological alterations induced in rats by Tityus serrulatus scorpion venom and its major neurotoxin tityustoxin-I

Intravenous injection into the rat of sublethal doses of Tityus serrulatus scorpion venom (100 micrograms protein/kg) or its major neurotoxin tityustoxin-I (TsTX-I, 20 micrograms/kg) caused, 30-180 min after injection, statistically significant increases in the serum levels of aspartate aminotransferase, amylase, creatine kinase and lactate dehydrogenase, as well as hyperglycemia, a high level of plasma free fatty acids and a low level of liver glycogen. The in vitro serum levels of the above enzymes did not change. For alanine aminotransferase, gamma-glutamyl transferase and alkaline phosphatase, neither in vitro nor in vivo alterations were observed. The whole venom and TsTX-I caused hepatic congestion with hemolysis and hydropic degeneration. Other histological lesions included edema and congestion with subpleural hemorrhage in the lungs, hypertrophy of fibers with degeneration areas in the heart, and congestion and hemorrhage in the kidneys. In the salivary glands, alterations to the acini and ductules were visible. In the adrenal glands no morphological alterations could be detected at the studied doses. The results suggest that the in vivo enzymatic and histopathological alterations are due to tissue lesions evoked by the whole venom and TsTX-I. An indirect effect, however, induced by stimulation of acetylcholine and catecholamine release in the postganglionic nerve terminals, cannot be excluded.

Scanning electron microscopy study of the interface epithelium-connective tissue surface of the lingual mucosa in Calomys callosus

The characteristics of the interface epithelium-connective tissue of the lingual mucosa of Calomys callosus was studied by employing scanning electron microscopy after removal of the epithelial cells. In the anterior part, the connective tissue papillae of filiform papillae are distributed at random in their original configuration, and the round-shaped fungiform papillae are scattered among the filiform papillae. In the middle part, the filiform papillae present several rod-shaped projections. In the posterior part, the vallate papilla are oval in shape, and the connective tissue reveals a large ridge separated by deep lateral grooves. The posterior adjacent area is a flat surface and shows several openings of salivary gland ducts. The foliate papillae are formed by several small ridges separated by grooves. In the areas adjacent to the foliate papilla, small pointed and laminar papillae were observed.

Effect of CO2 laser on Class V cavities of human molar teeth under a scanning electron microscope

The purpose of this study was to evaluate the effects of CO2 laser on dentin of class V cavities of extracted human molar teeth using a scanning electron microscope. SEM showed a smooth area with concentric lines formed by melting with subsequent recrystallization of dentin, areas of granulation, vitrified surface, numerous cracks, and irregular areas of descamative dentin. These data indicate that CO2 laser (4 and 6 watts) produces dentin alterations and limit its clinical applications.

The male reproductive organs in experimental Chagas' disease. III. Plasma testosterone and accessory sex glands in the acute phase of the disease

Male Wistar rats were injected i.p. with 2 x 10(5) trypomastigotes of the Bolivia strain. Fifteen days later, few parasite nests were observed in the fibromuscular layer surrounding the seminal vesicle acini of chagasic animals and no parasites were detected in the testis and ventral prostate. A significant decrease was observed in the absolute weight and fructose content of the seminal vesicle and ventral prostate of chagasic rats, which also presented a sharp decrease in plasma testosterone levels.

The male reproductive organs in experimental Chagas' disease. II. Morphometric study of the vas deferens in the chronic phase of the disease

A previous study showed that the vas deferens of mice in the acute phase of Chagas' disease had a slight increase in the muscle layer area associated with a small decrease in the luminal area. The vas deferens of chronic chagasic mice, investigated in the present experiment, presented a marked increase in the luminal area in addition to a significant thinning of the muscle and epithelium layers. The structural alterations of the vas deferens observed in the acute and chronic phases of Chagas' disease were compared with the evolution of chagasic esophagopathy.

The male reproductive organs in the chronic phase of experimental Chagas' disease

A previous study showed amastigote forms of Trypanosoma cruzi in the sex organs of male mice 15 days after inoculation. The purpose of the present work was to investigate the sequelae occurring in the male reproductive system during a later phase of Chagas' disease. Depleted germinal epithelium and release of immature germ cells into the tubular lumen were observed in the testis of chronic chagasic mice. The relative weights of the epididymis, vas deferens and seminal vesicle were significantly increased. Histological examination revealed a sharp thinning of the ductal and acinar walls. The results are discussed in terms of a neuromotor disturbance leading to sperm retention.

Histopathological study of von Ebner's lingual salivary glands in Trypanosoma cruzi-infected mice

In the present study we describe the histopathological alterations induced by RC strain of Trypanosoma cruzi in the mouse von Ebner's lingual salivary glands during the acute period of infection: Amastigotes were found in von Ebner's gland acini cells, excretory duct cells, intralobular connective tissue, inside the acini lumen and muscle fibres. Desorganized parenchyma with impairment at the acinar and duct level, and intense lymphoplasmocytic infiltrate were seen.

The male reproductive organs in experimental Chagas' disease. I. Morphometric study of the vas deferens in the acute phase of the disease

Amastigote forms of Trypanosoma cruzi (Bolivia strain) were detected in the sex organs of male mice 15 days after inoculation. The presence of the parasite close to the lumen of the seminiferous tubules and mixed with spermatozoa in the lumen of the epididymal duct suggests the possibility of transmission of Chagas' disease through coitus. Morphological analysis of the vas deferens revealed structural alterations compatible with the early form of chagasic esophagopathy.

A new aspect of the morphological transformation of Trypanosoma cruzi brought about by environmental variation

The development of Trypanosoma cruzi has been described both in vertebrate and invertebrate hosts, and the morphological transformations of the parasite have been studied in both cell-free cultures and tissue cultures. The investigators who studied this topic have emphasized the fact that the morphogenesis of T. cruzi may be associated with a series of factors. In the present study, we noted that when bloodstream trypomastigotes leave a vertebrate host reaching the digestive tract of triatomines through the blood sucking action of these vectors, specific culture by blood plating or maintenance of blood in physiological saline at different temperatures shows a phenomenon of trypanosome joining, with intensive movement of internal organelles (nucleus and kinetoplast) and junction at the kinetoplast level. Different situations may occur after this phenomenon, such as flagellate separation, passage of kinetoplast content from one individual to another, transformation into rounded elements that approach the pairs of agglomerate, or the formation of spherical elements similar to cyst-like bodies. When observed by light or phase-contrast microscopy, these bodies appear to be static and show inner structures moving in circles or in disorderly manner. On the basis of the molecular studies carried out by other authors, who observed that not all proteins synthetized from DNA are of immediate usefulness in the cell, but need to undergo activation by the action of another protein or of environmental variation, we may infer that T. cruzi, under adverse conditions, i.e. a change in habitat, may undergo transformations, taking on different forms for the exchange of genetic information for adaptation to the environment and for possible continuity of the evolutionary cycle.

[Morphologic and morphometric study of changes in the mouse parotid gland in the acute phase of Chagas' disease]

In the present study we describe the morphological and morphometric alterations induced by Bolivia strain of the Trypanosoma cruzi in the mouse parotid gland during the acute period of infection. The acinar cells exhibit reduced eosinophilia, greater chromatin condensation, reduced height and consequent dislocation of the nucleus towards the basal pole. Then lumen is reduced. The ducts are dilated and lined with low cylindrical epithelium. The septa are wider. An intense lymphoplasmocytic infiltrate is present. Amastigotes was found in glandular acini cells, striated duct cells, inter and intralobular connective tissue, muscle walls of blood vessels, and inside the striated duct lumen.

[Experimental hypervitaminosis A in the rat. 14. Morphological and morphometric study of changes in the esophageal epithelium]

Male rats were subjected to hypervitamin A treatment by daily intraperitoneal injections of 150 UI Arovit per g body weight. Another group of rats were injected intraperitoneally with saline solution for ten days and were used as controls. The results indicated that: 1) the body weight of animals treated with excess vitamin A was decreased; 2) histological analysis of the esophageal epithelium in treated animals showed increased thickness, characterizing a picture of hyperplasia and hypertrophy. On the basis of the results obtained, we suggest that excess vitamin A may act on the esophageal epithelium by direct action on the epithelial structures, stimulating and increase of the mitosis, and on the epithelium (mediated by the adrenals), resulting in increased thickness due to the concentration of a larger number of more immature cells. These alterations were more evident in the lower esophageal third.

Trypanosomes of Brazilian fishes. II. Trypanosoma barrettoi sp. n. from Hypostomus paulinus (Siluriformes, Loricariidae)

Trypanosoma barrettoi sp.n. is described from the blood of the armored catfish Hypostomas paulinus Ihering, from the State of São Paulo, Brazil. The total length averages 40.22 microns, of which 14.22 microns is free flagellum.

Morphological, morphometric and stereological study of submandibular glands in rats with lesion of the anteroventral region of the third ventricle (AV3V)

Lesions of the antero-ventral region of the third ventricle induce in the rat submandibular gland parenchyma, atrophy through vascular ischemia, and simultaneously increased fibrosis of the connective tissue, probably by alteration of the pituitary gonadotropins (FSH, LH), thyrotrophic hormone (TSH), growth hormone and probably insulin levels.

Can cocaine block the uptake of neurotoxin produced by Trypanosoma cruzi?

In the present study we describe the morphological and morphometric alterations induced by Trypanosoma cruzi (Bolivia strain) on the mice parotid gland, and the action of cocaine on the development of the gland of growing infected animals. The acinar cells of animals inoculated 28 d after birth showed reduced eosinophilia, greater chromatin condensation, reduced height, and basally dislocated nucleus. The area occupied by the acini was decreased and the nuclear volume was reduced. Reduced height of epithelial cells and decreased nuclear volume occurred in the striated and excretory ducts. The presence of lymphoplasmocyte infiltrates was also observed. The present results indicate delayed development of the infected mouse parotid gland. Our results indicate that cocaine perceptibly reduced the atrophy of the acinar cells and minimized the histopathological changes caused by T. cruzi in the parotid gland, in addition to significantly increasing the survival of infected animals. The presence of stroma with dilated capillaries and frequent inflammatory infiltrates showed that cocaine does not interfere with the inflammatory response.

[Morphometric and stereologic study of changes in the submandibular gland of mice with hypervitaminosis A]

Daily administration of 150 IU vitamin A/gram of body weight in mice, during 10 days, led the authors to observe: submandibular glands showed acini of slightly reduced size, with lower cells whose contours were not always sharp and containing smaller number of cytoplasmic granules. The nuclei of the acinar cells were reduced in volume. The granulose ducts were similar to those of the controls in size but showed signs of degeneration as well as cell nuclei of reduced volume. The striated ducts were smaller than those of the controls, while the excretory ducts were dilated, with lower cells and nuclei of reduced volume. General examination showed that the hypervitaminotic animals had more abundant connective stroma than the controls. The glandular structures were studied morphometrically and estereologically.

[Morphometric study of changes in the submandibular gland of aging rats. 2. Ducts]

A decrease in rat submandibular gland parenchyma could be observed with increasing age, consequent to an apparent increase in the proportion of intralobular ducts. Signs of acinar atrophy were noted with nuclei of smaller volume. A great variety of nuclear sizes and shapes was also observed. The blood vessels were smaller, and the connective tissue was increased. These histological data were confirmed in part by application of the technique of Chalkley. The granulous duct cell height is smaller in old animals.

Influence of age on the production of rat spermatozoa, on their concentration in the cauda epididymidis, and on FSH, LH and testosterone plasma levels

Testis samples were taken from young (3 months), middle-aged (12 months) and aged (24 months) male rats, processed, stained and examined via a light microscope. There were no prominent abnormal germinal epithelium and interstitial tissue. However, the aging process promoted a significant decrease in the mean amount of spermatids 19 per cross tubular section, and in the amount of Sertoli cells per cross tubular section in 24-month-old rats. The concentration of spermatozoa in the cauda epididymidis showed a gradual decrease from 3 to 12 and 24 months. After hCG injection all groups of animals exhibited an increase in plasma testosterone level, although the response was smaller in 12- and 24-month animals compared to the young mature (3 months) ones.

Morphological and morphometric study of the alterations on young mouse parotid gland with subpatent Chagas' disease

In the present study we describe the morphological and morphometric alterations induced by two Trypanosoma cruzi strains (strains Y and Bolivia) in the mouse parotid gland during the subpatent period of infection. The acinar cells of animals inoculated 27 d after birth showed reduced eosinophilia, greater chromatin condensation, reduced height, and basally dislocated nucleus. The area occupied by the acini was decreased (999.38 micron 2 to 546.76 micron 2) and the volume of the acinar cells was reduced (116.28 micron 3 to 63.28 micron 3). Reduced height (21.20 micron to 14.28 micron) and decreased nuclear volume (125.28 micron 3 to 77.28 micron 3) occurred in the striated ducts. In the excretory duct there was reduced nuclear volume (121.16 micron 3 to 76.14 micron 3) and decreased height of the epithelial cells (26.05 micron to 14.00 micron). The presence of lymphoplasmocyte infiltrates was also observed. The changes induced by the Bolivia strain were qualitatively similar to those induced by strain Y, but more severe in nature. The present results indicate that infection with T. cruzi induces delayed development of the mouse parotid gland during the subpatent phase.