Histological, immunohistochemical and pathological features of the pituitary gland of odontocete cetaceans from the Western gulf of Mexico.

Pituitary glands were recovered from dolphins and small whales found stranded along the Texas coast of the Gulf of Mexico over a 15-year period (1991-2006). One hundred animals of 14 species were found to be suitable for inclusion in this study. Of these, 72 were Atlantic bottlenose dolphins (Tursiops truncatus). Other species included were the melon-headed whale (Peponocephala electra), spinner dolphin (Stenella longirostris), striped dolphin (Stenella coeruleoalba), pantropical spotted dolphin (Stenella attenuata), pygmy sperm whale (Kogia breviceps), dwarf sperm whale (Kogia sima), Risso's dolphin (Grampus griseus), the short finned pilot whale (Globicephala macrorhyncha), false killer whale (Pseudorca crassidens), Fraser's dolphin (Lagenorhynchus hosei), rough-tooth dolphin (Steno bredanensis), Gervais's beaked whale (Mesoplodon europaeus) and an infant sperm whale (Physeter catodon). The pituitary weights in T. truncatus ranged from 0.69 g in a 109-cm long neonate to 3.44 g in a large (277 cm) male. More typical weights were in the range of 0.95-2.35 g (mean=1.65+/-0.70 g) The cetacean pituitary consisted of two distinct parts, the adenohypophysis and the neurohypophysis, which were separated by a thin fibrous membrane in all species examined, in contrast to terrestrial mammals in which the parts are apposed and joined through a pars intermedia. Cell types were identified with conventional stains and immunohistochemistry. Cells positive for adrenocorticotropic hormone, follicle stimulating hormone, growth hormone, melanocyte stimulating hormone, luteinizing hormone and prolactin were identified with appropriate antibodies. Lesions, which were few, included one pituicytoma of the pars nervosa and a squamous cyst in T. truncatus, and colloid cysts in several species. Nodular aggregates of single cell types were common, probably representing a physiological variant.

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'.

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.

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.

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.

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.

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.

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.

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.