Avian Amyloidosis

The incidence, staining qualities, organ distribution, age of affected individuals, and disease conditions associated with avian amyloidosis occurring in a population of 1698 zoo birds were analysed. Amyloid disease occurs in older birds, predominantly affecting the liver, spleen, and adrenals. The staining qualities and morphology are very similar to mammalian amyloid. The disease occurs mainly in exotic or poorly adapted birds, apparently related to environmental factors rather than to any specific predisposing disease.

Avian Amyloidosis

The incidence and contributing factors relating to amyloidosis in the family Anatidae were analysed by genus and species. There is a striking segregation of susceptibility by species, with exotic, poorly adapted or excessively aggressive birds being the most susceptible, and indigenous, well adapted non-aggressive or domestic types least susceptible. Other associations, such as chronic disease, are inconstant. Classifications such as primary and secondary amyloidosis do not apply to avian amyloidosis.

Sex-identifying urine and molt signals in lobster (Homarus americanus)

During courtship, premolt female lobsters,Homarus americanus, choose a male and initiate a pair bond by repeated approaches to his shelter. The male allows such a female to share his shelter for about one week. This knowledge formed the basis to search for quantitative evidence for lobster sex pheromone(s) used in courtship: male cues to allow premolt females to identify a preferred male, and female cues to allow males to identify a premolt mature female. In each of four 1500-liter naturalistic aquaria, the behavioral responses of one female and two male lobsters to male and female lobster urine (0.5 ml) and body odor (20 ml) stimuli were observed. These stimuli were injected once or twice per day into a continuously flowing delivery tube attached to lobster shelters. Habituation to stimulus introduction-a serious problem in earlier experiments-was apparently avoided in the more natural social and physical environment we employed in these experiments. We demonstrated that male and female molt body odors contain different chemical substances: females responded to male molt body odor and males responded to female molt body odor but not vice versa. In general, male and female intermolt urine caused strong responses; however, females responded only weakly to male urine. This suggests that male and female urine are chemically different. Female urine and molt body odor caused a typically male "high-on-legs" response. These results show that molt body odors and intermolt urine contain sex-specific substances, which may be used in lobster courtship as well as other social interactions.

Brucella sp. vertebral osteomyelitis with intercurrent fatal Staphylococcus aureus toxigenic enteritis in a bottlenose dolphin (Tursiops truncatus)

A previously beach-stranded, juvenile, male, bottlenose dolphin (Tursiops truncatus) was diagnosed with vertebral osteomyelitis of unknown etiology. Antemortem serological testing suggested past or current Brucella sp. infection; however, this could not be confirmed prior to death despite multiple isolation attempts from aspirates, blood, and biopsies. Systemic antibiotics were administered for over a year to control the suspected infection; however, the animal succumbed peracutely to infection by a highly pathogenic, enterotoxin-secreting Staphylococcus sp. Gross necropsy findings included a fistulous tract leading to locally extensive osteomyelitis of a coccygeal vertebra with sequestra and osteophytes from which a Brucella species was isolated. Histopathological examination of intestine revealed pseudomembranous enteritis with a uniform population of intraluminal Gram-positive cocci. Staphylococcus aureus was isolated in pure culture from the intestine and tested positive for the staphylococcal enterotoxin A gene by polymerase chain reaction analysis. Serum taken shortly before death had endotoxin and elevated antibody titers to staphylococcal enterotoxin A when compared to samples collected during a period of apparent good health 18 months earlier. The isolation of a pyrogenic toxin superantigen-producing staphylococcal isolate, clinical signs, and diagnostic findings in this animal resembled some of those noted in human toxic shock syndrome. The present case highlights the clinical challenges of treating chronic illnesses, complications of long-term antibiotic use, and promotion of pathogenic strains in cases of prolonged rehabilitation of marine mammals.

Histopathology of the alarm reaction in small odontocetes

Pathological changes in the organs and tissues of beach-stranded, net-caught or captive small odontocete cetaceans (whales and dolphins) are reported. These changes include contraction band necrosis of cardiac and smooth muscles, smooth muscle spasm, ischemic injury to the intestinal mucosa (especially the mucosa of the small intestine) and acute tubular necrosis (ATN) of the proximal tubules of the nephron. Spastic contraction of terminal bronchiolar muscular sphincters was also observed. The changes are consistent with multi-systemic injury caused by massive release of endogenous catecholamines or vasospasm leading to ischemic injury, followed by reperfusion and reperfusion injury. The histopathological findings suggest that the reflex response of an odontocete to any major perceived threat (the "alarm reaction") is to activate the physiological adaptations to diving or escape to an extreme or pathological level, resulting, if greatly prolonged, in widespread ischemic injury to tissues. These observations may explain why these species die abruptly from handling or transportation and why the mortality of highly stressed beach-stranded animals is very high.

A morphological and histological examination of the pan-tropical spotted dolphin (Stenella attenuata) and the spinner dolphin (Stenella longirostris) adrenal gland

The morphology and histology of the cetacean adrenal gland are poorly understood. Therefore, this study examined 32 pairs of adrenal glands from 18 pan-tropical spotted dolphins (Stenella attenuata) and 14 spinner dolphins (Stenella longirostris). In both species, the cortex was pseudolobulated and contained a typical mammalian zonation. Medullary protrusions (0-3 per section) and a medullary band were identified in both species. For S. attenuata, no statistical differences were found in the cortex to medulla (CM) ratio or the percent cross-sectional area (PCA) of the adrenal glands compared with sex or sexual maturity. The mean CM ratio for S. attenuata was 2.34 and the PCA was 64.4% cortex, 29.4% medulla and 6.2%'other'. 'Other' indicates blood vessels, connective tissue and the gland capsule itself. For S. longirostris, there was no statistical difference in the CM ratio compared with sexual maturity. However, a statistical difference was found between the CM ratio and sex, suggesting sexual dimorphism (female CM ratio = 2.46 and males = 3.21). No statistical differences were found in the PCA of S. longirostris adrenal glands by sexual maturity. However, a statistical difference was found between the PCA by sex. Female S. longirostris adrenal glands consisted of 65.0% cortex, 27.3% medulla and 7.7% 'other', whereas male adrenal glands consisted of 71.7% cortex, 22.7% medulla and 5.6% 'other'.

AMYLOIDOSIS IN TWO STEJNEGER'S BEAKED WHALES (MESOPLODON STEJNEGERI) STRANDED AT THE SEA OF JAPAN

Amyloidosis is a disease characterized by the tissue deposition of autologous extracellular fibrillar proteins that can result in compression of adjacent tissues. Amyloidosis is well-recognized in a wide variety of animals, including mammals, birds, and reptiles. However, to date, there is only one report of amyloidosis in cetaceans. During 1999 and 2000, among 12 Stejneger's beaked whales (Mesoplodon stejnegeri) that were stranded along the Sea of Japan's coast, amyloidosis was found in two whales (case 1, 498 cm, male; case 2, 520 cm, female). For this study population, the prevalence rate of amyloidosis was approximately 17%. These two animals were considered physically and sexually mature based on body length, external features, gonad characteristics, and skeletal features. Livers were notably swollen, fragile, and pale (brownish yellow) on gross examination. A large deposit of amyloid was found in Disse's spaces along with marked atrophy of the hepatocytes. Numerous granulomas, including many nematodes (Crassicauda sp.), were found along with amyloid deposition in the kidneys. Amyloid was also detected in the heart, spleen, adrenal gland, and pancreas. Amyloid in both cases was identified by typical morphology on H&E and Congo red staining. Electron microscopy displayed a typical network of fine fibrils measuring about 11 nm in diameter. This is the first report of amyloidosis in two Stejneger's beaked whales stranded on the coast of the Sea of Japan.

The Thyroid Gland in Bottlenose Dolphins (Tursiops truncatus) from the Texas Coast of the Gulf of Mexico: Normal Structure and Pathological Changes

Fresh thyroid glands (n=60) from Atlantic bottlenose dolphins that died after stranding along the Texas coast between 1991 and 2005 were examined. Organ weight ranged from 11 g in a neonate (length 109 cm) to 58 g in a large (249 cm) male. More typical weights were 25-45 g (mean=30.6 g). Glands tended to be larger in pregnant and lactating females (mean 37.4 g; n=5) than in non-pregnant animals of comparable size. In infancy, the gland tended to be compact, relatively homogeneous, and sometimes partly lobular, but with advancing age it became more lobular, the lobules being defined by fibrous bands. In one 8-year-old female (233 cm), and in a large male (295 cm) aged>25 years the gland was represented by a cluster of lobules. Lobulation was not necessarily accompanied by increased weight, distinguishing it from hyperplasia. With age, variation in follicle size and colloid density tended to increase. Two animals (3%) had adenomas and five (8%) had discrete hyperplastic nodules, not to be confused with lobulation. Five (8%) had macroscopically identifiable colloid-filled cysts (1-4 mm in diameter). Nine animals (15%) had squamous cysts (4-15 mm) containing creamy white fluid. Other abnormalities included patchy or diffuse interstitial fibrosis (six cases, 10%) amyloidosis (two cases), thyroiditis (one case) and vasculitis (one case). No malignant neoplasms were found. Cells presumed to be C cells (light cells, parafollicular cells) were identified immunohistochemically with synaptophysin antibody.

Morphological Changes in the Atlantic Bottlenose Dolphin (Tursiops truncatus) Adrenal Gland Associated with Chronic Stress

Beach-stranded Atlantic bottlenose dolphins (n=68) were categorized as either "acutely stressed" (if they died from net entanglement, boat strike, or acute infection; 31 animals) or "chronically stressed" (if they suffered from or died as a result of long-term disease or debilitating injury; 37 animals). No significant differences in mass between the right and left adrenal glands were found within each category. However, the average gland mass (AGM), based on the right and left glands together, was 5.2g for acutely stressed animals and 11.01 g for chronically stressed animals (P<0.001). Significant differences were also found, in terms of the ratio of cross-sectional areas of the cortex to medulla, between acutely stressed (ratio 1.22) and chronically stressed (ratio 1.63) animals (P=0.027). Adrenal glands of acutely stressed animals consisted of 48% cortex, 41% medulla, and 11% other tissue elements (connective tissue, blood vessels and gland capsule), whereas the corresponding figures for chronically stressed animals were 53%, 36%, and 11%. The mean estimated mass values for cortex, medulla and other tissue were, for acutely stressed animals, 2.36, 1.9, and 0.54, respectively, whereas for chronically stressed animals the corresponding figures were 6.06, 4.04, and 1.29 (P<0.001 for each of the three comparisons). Overstaining with haematoxylin (HEM) and immunohistochemical labelling (IHC) of the enzyme phenylethanolamine N-methyl transferase (which converts norepinephrine to epinephrine) were used to determine the percentage of epinephrine-producing cells in relation to the overall cross-sectional area of the adrenal gland. The percentage values in acutely as compared with chronically stressed dolphins were 6.7% and 15.93%, respectively (P=0.021). The results therefore suggest that in bottlenose dolphins chronic stress results in increases in (1) adrenal mass, (2) cortex to medulla ratio, and (3) epinephrine-producing cells within the medulla, giving rise to an increase in the thickness of the medullary band.

Volume density and distribution of mitochondria in harbor seal (Phoca vitulina) skeletal muscle

Recent studies have shown that harbor seals (Phoca vitulina) have an increased skeletal muscle mitochondrial volume density that may be an adaptation for maintaining aerobic metabolism during diving. However, these studies were based on single samples taken from locomotory muscles. In this study, we took multiple samples from a transverse section of the epaxial (primary locomotory) muscles and single samples from the m. pectoralis (secondary locomotory) muscle of five wild harbor seals. Average mitochondrial volume density of the epaxial muscles was 5.6%, which was 36.6% higher than predicted for a terrestrial mammal of similar mass, and most (82.1%) of the mitochondria were interfibrillar, unlike athletic terrestrial mammals. In the epaxial muscles, the total mitochondrial volume density was significantly greater in samples collected from the deep (6.0%) compared with superficial (5.0%) regions. Volume density of mitochondria in the pectoralis muscle was similar (5.2%) to that of the epaxial muscles. Taken together, these adaptations reduce the intracellular distance between mitochondria and oxymyoglobin and increase the mitochondrial diffusion surface area. This, in combination with elevated myoglobin concentrations, potentially increases the rate of oxygen diffusion into mitochondria and prevents diffusion limitation so that aerobic metabolism can be maintained under low oxygen partial pressure that develops during diving.

Morphology and Histology of the Atlantic Bottlenose Dolphin (Tursiops truncatus) Adrenal Gland with Emphasis on the Medulla

This study provides the first detailed description of the Atlantic bottlenose dolphin (Tursiops truncatus) adrenal gland with emphasis on the medulla. Thirty-one dolphins of varying age and sex were used in this study. No statistical differences were found between the right and left gland mass, however, the left was typically greater. Mean mass for the right and left adrenal glands were 4.99 +/- 0.513 and 5.36 +/- 0.558 g, respectively. No statistical differences were found between average gland mass and sexual maturity or sex. The average cortex/medulla ratio was 1.22 +/- 0.060 meaning approximately 48% is cortex, 41% is medulla, and 11% was categorized as other (i.e. blood vessels, connective tissue, etc.). The cortex contained pseudolobules and the typical zonation. A medullary band, consisting of highly basophilic staining cells was found at the periphery of the medulla. Projections of the medulla to the gland capsule were noted. Immunolabelling with polyclonal antibodies against the enzymes dopamine beta hydroxylase and phenylethanolamine N-methyl transferase indicated that noradrenaline producing cells are found throughout the medulla including the medullary band while adrenaline producing cells are only found within the medullary band. Transmission electron microscopy confirmed the presence of two distinct cell populations within the medullary band and a single cell population throughout the medulla.

Basaloid squamous cell carcinoma of the esophagus with or without adenoid cystic features

CONTEXT

Basaloid squamous cell carcinoma (BSCC) of the esophagus is a rare malignant tumor that morphologically could bear some resemblance to adenoid cystic carcinoma (ACC) originating from salivary glands.

OBJECTIVE

The purpose of this study is to describe the histologic, immunohistochemical, and ultrastructural findings of BSCCs of the esophagus, with an emphasis on comparing tumors with or without adenoid cystic features.

DESIGN

We reviewed 239 cases of primary esophageal carcinoma and detected 12 cases (5%) of BSCC. The light and electron microscopic findings and immunocytochemical localization of various antigens, including cytokeratins (AE1, AE3), carcinoembryonic antigen, epithelial membrane antigen, S100, smooth muscle actin, and p53, were examined in these BSCC cases.

RESULTS

Histologically, all BSCCs were composed of solid lobules or nests of basaloid cells with well-demarcated outlines surrounded by a fibrous stroma. Seven of 12 tumors showed areas of ACC-like features, that is, cribriform-like pseudoglandular lumina formation and hyaline material surrounding the tumor nests, whereas the remaining 5 tumors were apparently pure basaloid carcinomas. These 2 groups of tumors were histologically and immunohistochemically identical in many aspects, namely, high-grade nuclei of the tumor cells with frequent mitoses, abundant comedo-type necrosis, focal areas of concomitant squamous differentiation, consistent immunoreactivity for cytokeratins, and poor or absent staining for S100 and smooth muscle actin. Ultrastructurally, the basaloid tumor cells exhibited relatively undifferentiated cellular characteristics and undeveloped cell organelles.

CONCLUSION

Basaloid squamous cell carcinomas of the esophagus frequently have an intimate association with ACC-like patterns, but their histologic, immunocytochemical, and ultrastructural features correspond more to poorly differentiated squamous cell carcinoma than to salivary gland ACC. This distinction is important because genuine ACC is much less aggressive than BSCC.

Involution of lymphoid organs in bottlenose dolphins (Tursiops truncatus) from the western Gulf of Mexico: implications for life in an aquatic environment

Involution of lymphoid tissues in relation to age has not been defined for bottlenose dolphins (Tursiops truncatus). Twenty-five bottlenose dolphins from the coast of Texas and western Louisiana were examined and complete necropsies were performed with histological samples taken of nearly all tissues. Ages ranged from several days to 27 years. The histology of four lymphoid organs-thymus, pharyngeal tonsil, mucosa-associated lymphoid tissue (MALT) of the colon, and anal tonsil-was assessed. Numerical scores were assigned to specific morphological features, thus creating an involution score. Definable and scorable features of each organ were selected for evaluation and determination of loss of lymphoid elements. Neonatal dolphins were recorded as the reference standard for no involution. The highest score for each organ represented the greatest amount of retention of tissue elements. Thus, the lower the score, the greater degree of involution. Comparing involution scores to tooth age permitted an assessment of involution over time. The greatest degree of involution was found in the MALT of the colon. The MALT of the colon declined dramatically so that after age 10 it was absent from 4 of 14 animals and minimally present in 8 others. Thymic tissue also suffered a precipitous drop in volume after about age 5, but was found in animals up to 24 years of age. Involution was moderate and variable in both pharyngeal and anal tonsils. In some animals, these tissues were reduced in volume early, and prominent in others well into adult life (over 20 years).

Adaptations to diving hypoxia in the heart, kidneys and splanchnic organs of harbor seals (Phoca vitulina)

Pinnipeds (seals and sea lions) have an elevated mitochondrial volume density [VV(mt)] and elevated citrate synthase (CS) and beta-hydroxyacyl-CoA dehydrogenase (HOAD) activities in their swimming muscles to maintain an aerobic, fat-based metabolism during diving. The goal of this study was to determine whether the heart, kidneys and splanchnic organs have an elevated VV(mt) and CS and HOAD activities as parallel adaptations for sustaining aerobic metabolism and normal function during hypoxia in harbor seals (Phoca vitulina). Samples of heart, liver, kidney, stomach and small intestine were taken from 10 freshly killed harbor seals and fixed in glutaraldehyde for transmission electron microscopy or frozen in liquid nitrogen for enzymatic analysis. Samples from dogs and rats were used for comparison. Within the harbor seal, the liver and stomach had the highest VV(mt). The liver also had the highest CS activity. The kidneys and heart had the highest HOAD activities, and the liver and heart had the highest lactate dehydrogenase (LDH) activities. Mitochondrial volume densities scaled to tissue-specific resting metabolic rate [VV(mt)/RMR] in the heart, liver, kidneys, stomach and small intestine of harbor seals were elevated (range 1.2-6.6x) when compared with those in the dog and/or rat. In addition, HOAD activity scaled to tissue-specific RMR in the heart and liver of harbor seals was elevated compared with that in the dog and rat (3.2x and 6.2x in the heart and 8.5x and 5.5x in the liver, respectively). These data suggest that organs such as the liver, kidneys and stomach possess a heightened ability for aerobic, fat-based metabolism during hypoxia associated with routine diving. However, a heightened LDH activity in the heart and liver indicates an adaptation for the anaerobic production of ATP on dives that exceed the animal's aerobic dive limit. Hence, the heart, liver, kidneys and gastrointestinal organs of harbor seals exhibit adaptations that promote an aerobic, fat-based metabolism under hypoxic conditions but can provide ATP anaerobically if required.

Congenital diffuse hyperplastic goiter associated with perinatal mortality in 11 captive-born bottlenose dolphins (Tursiops truncatus)

Diffuse hyperplastic goiter was diagnosed by histopathology in 11 perinatal bottlenose dolphins (Tursiops truncatus) that died at four separate zoos and aquaria. Thyroid morphology of these animals was compared with the histologically normal thyroids of two stranded wild bottlenose dolphin calves, a neonate and a 2-mo-old calf. Histologic changes included reduced follicular luminal diameter, markedly reduced or absent luminal colloid, hypertrophy of follicular epithelium, and follicular dysplasia. The etiology of the thyroid gland lesion was not identified. Cause of death was not determined for most of these animals, but they were presumed to have died from metabolic derangements associated with the thyroid lesion, drowning, or dystocia.

Desmoplastic Small Round Cell Tumor of the Lung

An extra-abdominal desmoplastic small round cell tumor (DSRCT) of the lung with immunohistochemical, ultrastructural, and cytogenetic evidence of multidirectional differentiation is reported. We demonstrate that DSRCTs of the lung and pleura show morphologic, molecular, genetic, and ultrastructural features similar to DSRCTs arising in other sites. The tumor showed coexpression of cytokeratins (AE1/3, epithelial membrane antigen, CAM 5.2) and mesenchymal markers (vimentin, desmin, neuron-specific enolase), as well as WT1. Ultrastructurally, intracytoplasmic whorls of intermediate filaments, similar to previous descriptions of DSRCT in nonthoracic sites, were also demonstrated in this case. EWS-WT1 gene fusion characteristic of DSRCT with the t(11;22)(q13;q12) translocation was demonstrated in this tumor.

Comparative morphology of Lacazia loboi (syn. Loboa loboi) in dolphins and humans

Lacazia loboi (syn. Loboa loboi), the etiological agent of lobomycosis, was compared in human and dolphin tissue using light and electron microscopy, and computer-assisted morphometrics. The histological features of the lesions were similar; however, preliminary electron microscopy data indicates that cell wall destruction may vary in the two hosts. Calcofluor stained tissue sections of human and dolphin tissue were examined with UV light microscopy and the images digitized. Measurements of area, minimum and maximum diameters, and perimeter were made. Student's t-test (alpha = 0.01) revealed that L. loboi cells infecting dolphin tissue were significantly smaller than those infecting human tissue. This study represents the first comparative analysis of the morphology of the etiological agent of this disease in its two known natural hosts. The data indicate that the organism may not be identical in the two hosts.

Synovial joint disease in wild cetaceans

During necropsy of cetaceans stranded or accidentally net-captured along the western coast of the Gulf of Mexico from 1991 to 1996, we found 13 of 59 (22%) animals had abnormalities of the atlanto-occipital and/or humeroscapular joints, the synovial joints. A few cases demonstrated mild roughening of the articular cartilage, while the majority exhibited complete erosion with thickened synovium and bony proliferation. The lesions resulted in ankylosis of both joints in one animal. In humans and terrestrial mammals, synovial joint diseases are known to be debilitating. Cetaceans depend on neck and flipper movement for locomotion, feeding, avoiding danger, and reaching the water's surface for breathing. Therefore, synovial joint disease may be significant mortality factor in these marine animals.

Morphology of the lymphoid organs of the bottlenose dolphin, Tursiops truncatus

The anatomy of the lymphoid organs was studied during the course of detailed dissections of 50 beach-stranded bottlenose dolphins, Tursiops truncatus. Constant lymph nodes occur in 4 groups, based on their location and structure. These groups are somatic, including nodes of the cervical region and pelvic recess; lung-associated, included marginal, diaphragmatic and hilar nodes; visceral, including the mesenteric, pancreatic, pericolic and porta hepatis nodes; and aortic arch nodes. Lymphatic drainage of the lung is primarily to the marginal and diaphragmatic nodes. The mesenteric node mass is well-endowed with capsular and trabecular smooth muscle, and a network of muscle fascicles within the organ implies an important contractile function in the circulation of lymph. In addition to constant nodes, occasionally nodes are found in relation to the thoracic aorta, the kidney, and under the scapula. Gut-associated structures include dorsal and ventral oropharyngeal tonsils, mucosal aggregates in the straight segment of the intestine (colon) and anal tonsils; this gut-associated lymphoid tissue tends to involute with age, being greatly reduced by puberty. Formed lymphoid organs include the thymus and the spleen, the latter being relatively small in relation to body size. None of these structures is unique among cetaceans, but the anal tonsils are particularly well developed in T. truncatus. The lymphoid aggregates in the colon resemble the arrangement in the vermiform appendix, which is lacking in most cetaceans, and may have functions analogous to that organ.

High aerobic capacities in the skeletal muscles of pinnipeds: adaptations to diving hypoxia

The objective was to assess the aerobic capacity of skeletal muscles in pinnipeds. Samples of swimming and nonswimming muscles were collected from Steller sea lions (Eumetopias jubatus, n = 27), Northern fur seals (Callorhinus ursinus, n = 5), and harbor seals (Phoca vitulina, n = 37) by using a needle biopsy technique. Samples were either immediately fixed in 2% glutaraldehyde or frozen in liquid nitrogen. The volume density of mitochondria, myoglobin concentration, citrate synthase activity, and beta-hydroxyacyl-CoA dehydrogenase was determined for all samples. The swimming muscles of seals had an average total mitochondrial volume density per volume of fiber of 9.7%. The swimming muscles of sea lions and fur seals had average mitochondrial volume densities of 6.2 and 8.8%, respectively. These values were 1.7- to 2.0-fold greater than in the nonswimming muscles. Myoglobin concentration, citrate synthase activity, and beta-hydroxyacyl-CoA dehydrogenase were 1.1- to 2. 3-fold greater in the swimming vs. nonswimming muscles. The swimming muscles of pinnipeds appear to be adapted for aerobic lipid metabolism under the hypoxic conditions that occur during diving.

Angiomatosis, a newly recognized disease in Atlantic bottlenose dolphins (Tursiops truncatus) from the Gulf of Mexico

A new disease, angiomatosis, was recognized in 25 of 54 (46.3%) Atlantic bottlenose dolphins (Tursiops truncatus) necropsied after being stranded along the Texas Gulf coast during 1991-1996. Angiomatosis was first recognized by the authors in 1992 and has increased in incidence and severity, affecting 100% of juveniles and adults. This disease is characterized by proliferation of small, thick-walled blood vessels diffusely throughout the lungs, without inflammation, exudation, or alveolar hemorrhage. The vascular proliferation also occurs in lung-associated and other visceral lymph nodes. Hemangiomas frequently occur in affected lymph nodes and occasionally in the lungs. The vascular proliferation reduces airspace and may occlude small airways. Angiomatosis appears to be a broad-field defect of vascular endothelium. Although this process appears to be an increasingly important factor in the morbidity of T. truncatus, its etiology has not been determined.

Morphology of the complex laryngeal gland in the Atlantic bottlenose dolphin, Tursiops truncatus

A complex lymphoepithelial gland is a constant feature in the larynx of Atlantic bottlenose dolphins, Tursiops truncatus, based on study of 56 animals. Larynges were removed from fresh, non-decomposed beach-stranded animals for gross examination and histological sampling. A large lymphoepithelial gland occurs in the rostro-ventral mucosa of the larynx, overlying the cricoid cartilage. It presents as a well-defined, elevated, and heavily trabeculated area. Histological examination reveals a pseudostratified columnar epithelium which branches into the underlying submucosa. The epithelial-lined folds and crypts thus formed are surrounded by aggregations of lymphocytes, which infiltrate this epithelium. Mucous glands are often associated with these lymphoid aggregations. The histological appearance of the laryngeal gland is remarkably similar to the palatine, or dorsal oropharyngeal tonsils, of T. truncatus. It may be analogous to the nasopharyngeal adenoid of terrestrial animals. Age-related involution of the laryngeal gland is not as obvious with increasing animal age (or length) as it is in other mucosa-associated lymphoid tissue. The distribution of this gland among cetaceans is not yet known. We have observed it in individuals of every species we have studied, including Lagenodelphis hosei, Stenella coeruleoalba, Stenella attenuata, Globicephala macrorhynchus, Steno bredanensis, Physeter catodon, Pseudorca crassidens, Mesoplodon europaeus, and Kogia breviceps.

Automatic ultrasound determination of thermal coagulation front during laser tissue heating

Thermal therapies using laser, microwaves, radio frequency radiation, and high intensity focused ultrasound have shown great promise for minimally invasive treatment of benign and malignant lesions. To treat tissue effectively and safely, techniques that could monitor the advancement of coagulation front during treatment are highly desirable. This paper presents a noninvasive ultrasound technique for automatically determining the propagation of coagulation damage front during laser tissue heating. The basic assumption underlying this technique is that when coagulation is taking place in a tissue, owing to thermally induced structure changes in tissue, the waveform of echo signal scattered from that treated region should be changing accordingly. We first track echoes scattered from many small tissue regions during heating using a cross-correlation echo-tracking technique. We then use the waveform-change information to determine the position of coagulation front via an automatic calculation procedure. To test our technique, we carried out 35 experiments in which we irradiated fresh canine liver samples with a Nd:YAG laser (1064-nm wavelength) at various light fluence (62 to 167 W/cm(2)) and exposure time (20 to 350 s). A 13-mm diameter 10-MHz broadband single-element spherical focused ultrasound transducer was used to detect the thermal coagulation front. The root mean square difference between ultrasonically and visually determined coagulation depths was 0.77 mm. This good agreement between visually inspected and ultrasonically determined coagulation depths shows the potential of our technique for monitoring coagulative tissue damage during thermal therapy.

Isolation of fungal rDNA from bottlenose dolphin skin infected with Loboa loboi

Fungal-specific primers targeted for highly conserved genomic nucleic acid sequences were used in a polymerase chain reaction (PCR) to amplify DNA from lobomycosis lesions in a bottlenose dolphin. Sequence alignments of this DNA possessed high homology to fungal ribosomal DNA sequences found in the genus Cladosporium. When used for in situ hybridization, the riboprobe transcribed from a cloned PCR-generated fragment bound to Loboa loboi cells. These results support the hypothesis that L. loboi in dolphin tissue is a fungus.

Myocardial contraction band necrosis in stranded cetaceans

The term contraction band necrosis describes focal hypercontraction and lysis of small groups of myocardial cells. Contraction band necrosis of the myocardium was identified in 100% of 52 whales and dolphins (cetaceans) stranded along the western coast of the Gulf of Mexico between April 1991 and November 1996. The myocardial lesions in the cetaceans were identical, both grossly and histologically, to those previously described in man and other animals. Such lesions may contribute to the high mortality rate in stranded cetaceans.

Validation of the laboratory information system

OBJECTIVE

To present an organized and practical approach to the validation of laboratory information systems.

SOURCES

Personal experience, published papers, technical manuals, and Food and Drug Administration guidelines.

DATA

Validation of the laboratory information system is the continuing process of proving the system fit for its intended use, initially and over time. It consists in defining, collecting, maintaining, and independently reviewing evidence that the system will perform consistently according to specification. Validation is tedious, difficult, and costly, but it must be done to assure that the system is fit for use and is working according to specification. In addition to professional and licensing bodies, laboratories making blood products fall under the regulatory requirements of the Food and Drug Administration. The buyer of a system is responsible for verifying that the developer has complied with all regulations and that the software products are validated to an appropriate degree, that the hardware is certified to perform its designated functions, that an appropriate period of acceptance testing has been done and documented, and that the system in use performs to specification and is under control.

CONCLUSION

System validation demonstrates to all concerned, inside and outside the laboratory, that the laboratory information system manages information well, with the expected accuracy and reliability, file integrity, auditability, and management control.

Testicular "tumor" of the adrenogenital syndrome: a case report of an unusual association with myelolipoma and seminoma in cryptorchidism

BACKGROUND

Males with congenital adrenal hyperplasia may develop bilateral testicular masses in early adult life. These are not malignant and generally regress with corticosteroid therapy. The authors report a case occurring in a 44-year-old man with associated seminoma and myelolipoma in an undescended testis.

METHODS

The testicular tumors were analyzed by histologic, flow cytometric, and ultrastructural techniques.

RESULTS

The tumors in both testes were comprised of polygonal cells with abundant granular eosinophilic cytoplasm, occasionally with brown (lipochrome) pigment and round nuclei of various sizes with prominent nucleoli. These cells were grouped into nodules by dense and sometimes thick fibrous trabeculae in the right testis. The areas corresponding to the fibrous trabeculae in the left (intraabdominal) testis were replaced by mixture of hematopoietic (myeloid) and fatty tissue in various proportions characteristic of myelolipoma. The left testis also had a well demarcated tumor that was diagnostic of seminoma. Electron microscopy demonstrated abundant smooth endoplasmic reticulum, a moderate number of mitochondria with tubulovesicular cristae, lipid droplets, and lipofuscin granules in the polygonal cells. No Reinke's crystals were observed. The patient received corticosteroids for his adrenocorticoid deficiency and also underwent external beam irradiation to the retroperitoneum for seminoma.

CONCLUSIONS

This case illustrates an unusual presentation of a testicular tumor in a patient with the adrenogenital syndrome as well as with myelolipoma and seminoma in a cryptorchid testis. The possibility of an associated neoplasm that could be potentially fatal should be considered whenever a testicular tumor of the adrenogenital syndrome continues to grow despite adequate hormonal treatment.

Bifid mandibular condyle

The bifid mandibular condyle remains a relatively uncommon entity although the number of reports continues to accumulate, usually as incidental radiographic findings. It would appear that it may arise in at least two different ways, traumatically and developmentally. A case is presented of a unilateral bifid condyle in a young female. From the radiological examination, including CT, the left condyle was seen to be divided medio-laterally by a groove located on the anterior aspect. A history of trauma was inconclusive and no link was apparent with respect to the patient's medical history. Since the patient's original complaint improved with the management of her oral symptoms and the provision of new dentures, no other treatment of the joint was indicated. The case is discussed in connection with the relevant literature.

Mechanism of healing of the human prostatic urethra following thermal injury

OBJECTIVES

To characterize histopathologically the healing response of the prostatic urethra after laser thermal coagulation and standard transurethral resection of the prostate (TURP).

METHODS

The study included 31 patients who underwent radical prostatectomy because of malignancy. Twenty-two (first group) had laser radiation either at the time of surgery (18 patients) or from 1 to 12 weeks prior to prostatectomy (4 patients). Nine patients (second group) had TURP from 6 to 96 weeks prior to prostatectomy.

RESULTS

Coagulation necrosis followed by sloughing was observed during the first 10 weeks after laser radiation. After the first 10 weeks, the healing response was otherwise stereotypical and comparable for both groups of patients. Re-epithelialization was prominent and resulted from migration of proliferating epithelial cells from the remaining acinar and ductal epithelium. Squamous metaplasia was conspicuous and present indefinitely. Development of inflammatory reaction followed by granulation tissue and well-organized fibroblastic stroma were sequentially recognized, but less prominent. Complete re-epithelialization and wound sealing was not observed before the first 12 weeks of healing.

CONCLUSIONS

Our study suggests that laser thermal coagulation and TURP are partial-thickness injuries. Because of the abundant germinal epithelium in the remaining prostatic glands and ducts, the healing response of the prostatic urethra is relatively unimpeded and free of contractures, analogous to second-degree skin burns.

Histopathologic effects of laser radiation on the human prostate

High levels of applied laser irradiation to the prostate will carbonize or vaporize tissue, and may cause explosive expansion of superheated tissue water. Lower levels, used most often to relieve obstruction caused by benign prostatic hypertrophy, will cause coagulation necrosis. This effect is apparent within 1 h of application. In contrast to the canine, in which laser-coagulated prostate sloughs in 2 to 3 weeks leaving a smooth cavity, in the human necrotic tissue is sloughed irregularly over a period ranging up to 12 weeks. This difference is attributed to the dominantly glandular nature of the canine prostate, and the dense fibromuscular composition of the human prostate stroma. Sloughing is accomplished by surface liquefaction, cavitation of the necrotic coagulum, and to a lesser degree, formation of granulation tissue at the margins. As often occurs at the margin of spontaneous infarcts in the prostate, squamous metaplasia may be prominent at the margins of laser-induced coagulation necrosis.

Thermocoagulation effect of diode laser radiation in the human prostate: acute and chronic study

OBJECTIVES

To evaluate the safety and efficacy of low-power slow-heating diode laser-induced photocoagulation of prostatic tissue for treatment of benign prostatic hyperplasia, we conducted a series of acute and chronic studies using a diode laser (810 nm) to irradiate human prostate.

METHODS

The study included 6 patients undergoing radical prostatectomy because of malignancy. Laser radiation to the prostate was given transurethrally, in a noncontact mode, at the time of the procedure in 2 patients (acute group): 10 W for 300 seconds on the right side of the prostate and 15 W for 180 seconds on the left. In the remaining 4 patients (chronic group), laser radiation was given at 1, 7, 10, and 12 weeks prior to the prostatectomy.

RESULTS

In the acute group the average depth of coagulation was 8.5 and 9.0 mm for the laser regimens of 15 W for 180 seconds and the 10 W for 300 seconds, respectively. In the chronic group, the average depth of coagulation was 8.9 mm for both laser regimens studied. In the acute group, there was an ill-defined hemorrhagic ring at the periphery of the lesion. At 1 week, an intact necrotic coagulum was present. At 7 weeks, some of the coagulated tissue had already sloughed off. Longer follow-up at 10 and 12 weeks demonstrated formation of a well-defined cavity with mostly re-epithelialized surface.

CONCLUSIONS

Our findings suggest that noncontact diode laser (810 nm) irradiation can induce in the human prostate significant coagulation necrosis followed by sloughing of tissue and cavitation of the prostatic urethra.

Histopathological evaluation of laser thermocoagulation in the human prostate: optimization of laser irradiation for benign prostatic hyperplasia

We have previously shown in a canine prostate model that a noncontact low power neodymium:YAG laser regimen of 15 watts for 180 seconds yields a larger volume of coagulation necrosis than the currently recommended high power regimen of 50 watts for 60 seconds. These 2 regimens have not yet been compared in humans. The objective of this study was to evaluate histopathologically the thermocoagulation effect of these 2 laser regimens in the human prostate and the effect of the spatial distribution of the laser lesions on the extent of coagulation necrosis. The study was conducted in 10 patients undergoing radical prostatectomy or cystoprostatectomy. The laser treatment was given transurethrally 1 hour before removal of the specimen. There were no fractures of the prostate. The coagulation necrosis did not reach the peripheral zone and it was minimal in areas rich in fibromuscular tissue, such as the bladder neck. At times, nodular benign prostatic hyperplasia was unaffected. A 4-quadrant treatment in the same plane often yielded small nonconfluent lesions. Confluent lesions in the same plane yielded approximately 30% greater depth of coagulation necrosis, which was achieved when 3 or 4 lesions were created on each side of the prostate (per single transverse plane). Likewise, coagulation necrosis observed with 15 watts for 180 seconds was approximately 40% greater than that noted with the 50 watts for 60 seconds regimen. Our findings suggest that noncontact laser prostatectomy is a safe procedure that can be improved by modifying the laser regimen and the spatial distribution of lesions.

Amyloidosis in the bottlenose dolphin, Tursiops truncatus

Four cases of amyloidosis were recognized in a study population of 21 (19%) bottlenose dolphins (Tursiops truncatus) examined as part of an investigation of the causes of cetacean strandings along the Texas Gulf Coast. Amyloid deposition was mainly and most prominently in the corticomedullary regions of the kidneys and less consistently in the vessels of the spleen, lung, and heart and around acini of the palatal salivary gland and the thyroid gland. Pretreatment of sections with permanganate and sulfuric acid greatly diminished Congo red staining, suggesting the dolphin amyloid is of the AA variety.

Nd: YAG laser thermocoagulation of the prostate: the barbecue effect

OBJECTIVE

To determine systematically the depth of coagulation necrosis induced during Nd: YAG laser irradiation in the canine prostate model, and to define the correlation of laser dose with depth of the lesions.

METHODS

We investigated the effect of various dosimetries on prostatic tissue of 17 mongrel canines using laser power in the range of 8 to 60 watts (W) at varying exposure times, from 20 to 300 seconds (S). Applied energy ranged from 1,000 to 5,500 Joules (J).

RESULTS

Three distinct features were observed. First, deep coagulation necrosis was induced only with laser regimens of > or = 2,100J, suggesting that there is a threshold of energy that must be overcome in order to achieve significant coagulation depth. Second, the deepest coagulation necrosis was achieved with a low power slow-heating regimen (15W X 180S). Tissue surface changes appeared to be responsible for the reduced depth of coagulation necrosis seen with higher power regimens (> 20 W). Third, increasing the energy above 3,600J did not augment the depth of coagulation, suggesting that a steady state for temperature distribution is reached at that rate of heating.

CONCLUSIONS

Our study suggests that in the canine prostate, a low power slow-heating regimen of 15W X 180S may yield larger volumes of coagulation necrosis than other regimens.

Morphology of complex lymphoepithelial organs of the anal canal ("anal tonsil") in the bottlenose dolphin, Tursiops truncatus

A complex of lymphoepithelial organs, the "anal tonsils," is a consistent structure in the anal canal of the bottlenose dolphin, Tursiops truncatus. This complex occurs as a circumferential cluster of discrete tonsil-like aggregations of lymphoid tissues, together with epithelial ducts ("crypts") and occasional mucus secretory units in the extreme lower portion of the intestinal tract. These structures are concentrated in the segment lined by stratified squamous epithelium and extend for a variable distance cephalad from the anal aperture. The tonsils appear to be most active, judged by the amount of lymphoid tissue present, in young animals. Depletion of lymphocytes and cystic enlargement of the crypts, probably representing functional as well as morphological involution, is a consistent feature of older animals.

Comparison of thermocoagulation effects of low power, slow heating versus high power, rapid heating Nd: YAG laser regimens in a canine prostate model

We compared the thermocoagulation effects of low power, slow heating (15 W x 180 seconds) versus high power, rapid heating (50 W x 60 seconds) laser regimens in the canine prostate. The study was performed in 20 mongrel canines. On each prostate, the low power regimen was delivered at the 2 and 4 o'clock positions, and the high power at the 8 and 10 o'clock positions. The laser power was measured at the fiber tip. Seven dogs (acute group) were sacrificed 1 hour after the procedure. The other 13 dogs (chronic group) were sacrificed at different time intervals from 3 days to 9 weeks after the procedure. The average depth of coagulation was significantly greater in lesions treated at low power (acute: 10.7 mm., chronic: 13.3 mm.) than in those treated at high power (acute: 8.5 mm., chronic: 11.6 mm.). Another potential benefit of the low power regimen observed in the study was preservation of the integrity and efficiency of the laser probe.

Laser photocoagulation of prostate: influence of dosimetry

BACKGROUND AND OBJECTIVE

Recently, increasing enthusiasm has been shown for application of lasers for the treatment of benign prostate hyperplasia (BPH). However, little is known about the thermodynamics of prostatic tissue response during laser irradiation and how the treatment outcome can be optimized. Our objective was to conduct a systematic study of the influence of exposure parameters on the extent of tissue coagulation and to determine the effects of rate of tissue heating on lesion size by comparing the tissue response to high laser power rapid heating vs. low laser power slow heating.

STUDY DESIGN/MATERIALS AND METHODS

Nd:YAG laser irradiation of prostate was performed in 15 mongrel canines, using an incident power of 15, 30, or 50 Watts (at the fiber tip) and an exposure time varying from 30 to 300 seconds. The laser beam was delivered via a Urolase side-emitting catheter. The tissue response was compared based on gross as well as histological evaluations of thermal lesions.

RESULTS

The depth of coagulation necrosis increased as the laser power was reduced from 50 W to 30 W and further to 15 W while the total delivered energy was kept constant at 2,700 J by adjusting the exposure time. The difference between the three heating rates was more dramatic when the estimated volume of coagulated tissue was considered. Increasing the irradiation time for the low power (15 W) from 180 to 300 seconds resulted in enlarging the coagulated volume by a factor of 1.6. However, for high power (50 W), increasing the exposure time from 54 to 90 seconds resulted in increasing the coagulated volume by a factor of 1.2.

CONCLUSION

This study suggests that a slow heating regimen yields larger volumes of coagulation necrosis than the currently used rapid heating approach.

Involution and cystic transformation of the thymus in the bottlenose dolphin, Tursiops truncatus

The thymus glands of 10 bottlenose dolphins, Tursiops truncatus, collected along the Texas Gulf coast were examined using standard histologic and immunocytochemical methods. The thymus gland of Tursiops persists into adult life, represented by medulla and progressively thinning cortex. A network of epithelial cells, including Hassal bodies, is demonstrable using polyclonal anti-cytokeratin antibody. The network condenses, with loss of lymphoid cells as involution progresses. Cysts arise within the condensed network. These cysts, found in eight of 10 animals, increase in number and size with increasing body size. Body size tends to reflect age. Thymic cysts typically have an irregular shape when small but tend to become spherical as they enlarge. They may be lined by squamous epithelium of variable thickness. Eventually, the cysts become macroscopic and filled with a colloidlike material and may largely replace the thymus, which may be identified by noncystic remnants adjacent to the cysts.

Recurring phyllodes tumor in aberrant breast tissue of the vulva

A 20-year-old nulligravida woman presented with bilateral cystic nodules of the vulva, diagnosed after simple excision as benign phyllodes tumor. Breast tissue, which also displayed fibrocystic changes, was also recognized. Follow-up at 2 months revealed no evidence of disease; however, 8 months after surgery she returned with a new mass in the vulva. This was excised and found to be recurrent phyllodes tumor. Although somewhat more cellular than the first lesions, it also was deemed to be benign based on histological features supported by flow cytometric DNA studies.

Lobo's disease in a bottlenose dolphin (Tursiops truncatus) from Matagorda Bay, Texas

Lobo's disease was diagnosed in a free-ranging male bottlenose dolphin Tursiops truncatus examined as part of a live-capture and release program conducted in Matagorda Bay, Texas, USA, during July 1992. Diagnosis was based on typical presentation of a raised skin lesion, with sub-epidermal granuloma and demonstration of typical features of the organism by light microscopy, using hematoxylin and eosin, and methenamine silver stains. This is the first instance of Lobo's disease found in a dolphin on the western coast of the Gulf of Mexico.

Implementing a regulation-complaint quality improvement program on a commercial laboratory information system

Implementing a quality improvement (QI) program on an automated laboratory information system (LIS) in the current regulatory climate requires first that the QI program be defined and second that the selected LIS be able to capture important events and use flexible vendor-provided or user-defined routines to prepare reports. Reports key on specific monitors and thresholds defined in the QI program. The product of a pathology laboratory is communicated information. The QI program focuses on the accuracy, clarity and timeliness with which the whole information-generating process functions. To support peer review the LIS must be able to select reports for evaluation based on user-defined parameters, such as diagnosis keyed through Systematized Nomenclature of Medicine codes, or by random or pattern selection by accession number. Counting and review of revised reports will focus attention on accuracy and skill in communication since these indicators often reflect client satisfaction with the report. To link services--e.g., cytology with surgical pathology--the LIS must be able to gather cases from the accession lists of both services and to flag diagnostic inconsistencies. LIS transaction logging at every step in the information process allows tracking of work load, productivity and resource utilization by functional areas and by individual, thus meeting regulatory requirements. Transaction logging also provides management information, such as segmented turnaround time audits, pinpointing sources of delay by kind and location of work or individual involved. Critical data must be held on-line for at least five years.

Transitional cell carcinoma with rhabdoid features

We discuss the light-microscopic, immunohistochemical, electron-microscopic, and flow cytometric analysis in a case of invasive transitional cell carcinoma of the renal pelvis with rhabdoid features and glandular metaplasia. This tumor demonstrated in situ rhabdoid transformation of the transitional epithelium, which has not been described before. Electron-microscopic examination of the rhabdoid cells revealed whorled aggregates of intermediate filaments. There was also evidence of mucin-filled intracellular lumina on light and electron microscopy in both in situ and invasive components of the tumor. Our findings lend support to the view that tumors with "rhabdoid" features in adults and perhaps some children represent a heterogeneous group of neoplasms, some of which may just be unusual morphologic variants of a transitional cell carcinoma, in contrast to the distinct clinicopathologic entity of childhood renal rhabdoid tumors.

The Role of Olfaction in Courtship Behavior of the American Lobster Homarus americanus

Courtship behavior is well documented in captive lobsters. Sex pheromones contained in female urine and perceived by receptors on male antennules are thought to act as sex attractants or as signals necessary for pair formation. In this study, the lateral and medial antennules of male and female lobsters were removed. The result of these excisions were meant to indicate the gender-specific role of olfactory chemoreception in lobster courtship behavior. Removal of male antennules had little effect on pair bonding and mating. In contrast, removal of female antennules resulted in dramatic aberrations in behavior, including postmolt injuries and, in extreme cases, unsuccessful couplings and mortality. Therefore, female olfaction plays the more critical role in the normal reproductive behavior of Homarus americanus.

Elastosis in the normal aging breast. A histopathologic study of 140 cases

The incidence and pattern of elastosis of the breast was studied in tissue specimens taken at autopsy from 140 women with clinically normal breasts, ranging in age from 19 through 101 years. Elastosis, presence of excess elastic fibers, while less common in younger women, may be found in nearly half of all women over age 50 years with no breast disease. Elastosis occurs in three sites: diffusely in the stroma, around vessels, and around ducts. In the first two sites, it bears little relationship to age, while periductal elastic tissue appears to accumulate with age, probably reflecting parity, until about age 50 years. Thereafter, it is found at a more or less constant incidence and degree. While it may be associated with breast cancer, periductal elastosis by itself is not a cause for concern. Marked perivascular elastosis is, however, uncommon at any age, and its presence should suggest a special search for carcinoma, if not already evident.

A microcomputer based system for three-dimensional reconstructions from tomographic or histologic sections

The reconstructions of three-dimensional (3-D) objects from serial two-dimensional (2-D) images can contribute to the understanding of many biologic structures, from organelles to organs and tissues. The 3-D reconstruction of sections can be divided into several major tasks: image acquisition, alignment of slices, internal object definition, object reconstruction and rotation of the completed image. A fast, versatile, interactive system was devised for the reconstruction of 3-D objects from serial 2-D images using a low-cost microcomputer, original programs and commercial software. The system allows reconstruction from any serial images, e.g., electron micrographs, histologic sections or computed tomograms. A photographic image or a microscopic field is acquired into the computer memory using a video digitizer. Slices are superimposed and aligned to each other using an operator-interactive program. A contour-(edge-) finding algorithm isolates an object of interest from the background image by "subtraction" of the image from an overlaid, slightly shifted identical image. Contours for each slice are input to a reconstruction procedure, which calculates the x, y and z coordinates of every point in a slice and the thickness and number of slices. It then calculates the illumination for every point using a given point source of light and an intensity-fading coefficient. Finally, the points are represented by cubes to provide dimension and reflective surfaces. A cube of appropriate shade and color represents in 2-D the equivalent of a 3-D object; this results in a very effective 3-D image. The reconstruction is rotated by recalculating the positions of every point defining the object and rebuilding the image.(ABSTRACT TRUNCATED AT 250 WORDS)

Quality assurance in anatomic pathology. An information system approach

Quality assurance (QA) is the outcome-oriented process by which the performance of a complex production operation is evaluated. It is strongly focused on the use of resources and the end product, and is closely related to marketing. The pathologist's product is information, and the practice of anatomic pathology is evaluated as a system for producing and effectively communicating information. Our integrated program for QA in surgical pathology, autopsy pathology, and cytopathology recognizes that several discrete elements make up the sequence leading to communication of the diagnostic opinion. These are control and processing of the specimen, accuracy of diagnosis, timely and clear communication, efficiency in production of information, coherence with institutional programs in QA, and relation to licensing and accreditation agencies. Each of these elements may be tested separately and sources of error reduced so that the validity and cost of the pathologist's prediction will ultimately be limited only by the state of the art and not by any failure of the information system. Several components of QA, especially resource utilization by pathologists, are potentially productive areas for operations research.

A microcomputer-based algorithm for digitized image simplification and information extraction

Spatial analysis of objects often requires significant image simplification prior to information extraction and application of a decision-making algorithm. Much decision making based on images (e.g., histologic diagnoses) requires identifying patterns in complex backgrounds (image simplification) and comparison of those patterns to other patterns (decision making). Automated extraction of information from images commonly requires the extraction system to recognize edges (contours) of structures and their internal discontinuities (such as gradations in density) and to selectively suppress irrelevant data in order to conserve memory and speed computation; data from homogeneous image areas occupy memory, but are noncontributory or redundant. This paper describes the development of a microcomputer-based algorithm that deletes all homogeneous information from overlaid digitized images, generating contours in the place of nonhomogeneities. Contours corresponding to different areas or objects depend on color differences between an object and its surroundings. Any set of contours can be deleted almost instantaneously, leaving only those of interest. Contours can be highlighted by an operator-driven interactive process if desired and can be deleted and retrieved until an appropriate image is obtained. This contour-generating and image-simplification algorithm facilitates three-dimensional reconstruction of an object from serial images by reducing the number of calculations required and yielding a cleaner final image.