Acute lead toxicosis in a harbor seal (Phoca vitulina richardsi) consequent to ingestion of a lead fishing sinker

An adult female harbor seal (Phoca vitulina richardsi) stranded in northern California on 25 June 2004, exhibited progressive weakness, disorientation, and seizures, and despite therapy, died within 4 days. On pathologic examination, a lead fishing sinker was in the stomach, and changes in the brain, heart, kidney, liver, lymph nodes, and spleen were supportive of acute lead toxicosis. The diagnosis was made on the basis of concentrations of lead in the sinker (90-98% lead), antemortem whole blood (0.66 ppm), and postmortem tissues (84 ppm, wet weight liver). This first documented case of lead toxicosis in a wild marine mammal demonstrates an additional way in which human fishing activities can harm marine mammals.     

Persistent right aortic arch and cribiform plate aplasia in a northern elephant seal (Mirounga angustirostris)

A female weanling northern elephant seal (Mirounga angustirostris) presented to The Marine Mammal Center in Sausalito, California, USA, in poor body condition. An esophageal obstruction was diagnosed by contrast radiography and esophagoscopy, but despite extensive diagnostics and supportive care, the seal died 6 days later. On postmortem examination, the right aortic arch was persistent, forming a vascular ring anomaly with a patent ductus arteriosus that compressed the distal esophagus. Aplasia of the right cribiform plate and hypoplasia of the right olfactory nerve was also identified. A review of necropsy reports from January 1988 to December 2003 revealed 16 severe congenital anomalies in 454 juvenile northern elephant seals that stranded in northern California.     

Lymph node cell responsiveness in BALB/c mice infected with Leishmania mexicana

In the present study we measured the blastogenic response of lymph node cells from BALB/c mice infected with Leishmania mexicana throughout the course of infection. Results showed that infected mice displayed normal blastogenic responses in the lymph nodes until twenty weeks of infection. Thereafter, there was a gradual suppression. Comparison of the immunoresponsiveness in the spleen and lymph nodes, revealed normal responses in the lymph nodes several weeks after suppression in the spleen had occurred. Suppression of blastogenic responses in the lymph nodes was related to an adherent macrophage-like cell which actively suppressed normal proliferative responses to mitogens.     

Characterization of Otostrongylus circumlitus from Pacific harbor and northern elephant seals

Otostrongylus circumlitus (Railliet, 1899) from Pacific harbor seals (Phoca vitulina richardsi) and northern elephant seals (Mirounga angustirostris) were examined using morphological and molecular methods to determine whether northern elephant seals along the central California coast are infected by the same species of Otostrongylus as are Pacific harbor seals in the same area. Fixed nematodes were examined and measured using light microscopy. The polymerase chain reaction (PCR) was used to amplify and sequence the second internal transcribed spacer (ITS-2) and D3 expansion (26S) regions of ribosomal DNA of O. circumlitus from Pacific harbor and northern elephant seals. The ITS-2 region was also amplified from Parafilaroides sp. from the Pacific harbor seal, northern elephant seal, and California sea lion (Zalophus californianus) and used for restriction fragment length polymorphism (RFLP) analysis. Morphologically, it was not possible to distinguish O. circumlitus from Pacific harbor and northern elephant seals, and over a consensus length of 443 base pairs (bp) for ITS-2 and 321 bp for D3 the sequences of O. circumlitus from both hosts were identical. With the PCR-RFLP assay, it was possible to distinguish O. circumlitus from Parafilaroides sp. The results suggest that O. circumlitus is the same species in Pacific harbor and northern elephant seals, and molecular methods make it possible to distinguish this nematode from related nematodes.     

Records of Northern Elephant Seals,Mirounga angustirostris Gill, 1866 (Mammalia: Phocidae), from the Kuril Islands

Russian Journal of Marine Biology - The northern elephant seal does not inhabit the waters of Russia. Encounters with this animal are rare and in most cases occur at rookeries of eared seals. The...     

Lymphosarcoma in an infant northern fur seal (Callorhinus ursinus)

An infant northern fur seal (Callhorinus ursinus) died in a rookery on St. Paul Island, Pribilof Islands, Alaska. Grossly, slight enlargement of the mesenteric lymph nodes was seen. Microscopically, a lymphosarcoma composed of sheets of monomorphic lymphoid cells in sections of lymph node and tonsil was seen. Electron microscopy of formalin-fixed tissues revealed several structures that were possible of viral origin in the cytoplasm of the neoplastic cells.     

Impact of population bottlenecks on genetic variation and the importance of life-history; a case study of the northern elephant seal

This paper reviews some of the important factors related to the impact of population bottlenecks, using the northern elephant seal (Mirounga angustirostrus) as a case study for illustration. The northern elephant seal was hunted extensively in the 19th century and forced through a bottleneck of approximately 10–20 seals. All measures of molecular genetic variation show current levels for the northern elephant seal to be low. Levels of genetic variation were compared with expectations based on a simulation model that recapitulates demographic growth, based on age-specific data on reproduction and mortality. Predictions from the simulation model are then presented to illustrate the importance of differences in life-history strategy and skewed reproductive success. Either high reproductive skew (e.g. polygyny) or a low growth rate in a population can increase the impact of a bottleneck on molecular variation. Severe population bottlenecks can also disrupt aspects of developmental stability and thereby increase the fluctuating asymmetry and variability of quantitative traits. A comparison of skulls collected before and after the bottleneck showed this to have occurred for some elephant seal quantitative characters.     

Detection and quantification of IgM(+) lymphocytes in fetal lamb spleen, liver and lymph nodes by flow cytometry

The first stage in Peyer's patch development in the fetal lamb is characterized by the colonization of the rudimentary Peyer's patches by precursor cells expressing the IgM surface receptor. In the fetal lamb, the spleen has been implicated as the source of gene-rearranged IgM(+) B lymphocytes. This study was intended to quantitate IgM(+) lymphocytes in the spleen, lymph nodes and liver of fetal lambs at various gestational ages between 63 and 110 days using flow cytometry. Flow-cytometric analysis revealed that IgM(+) lymphocytes were rare in the liver being consistently less than 1% at every gestational age examined. IgM(+) lymphocytes were detected in the spleen (mean 9.18%) and prescapular lymph nodes (mean 11.89%) as early as 63 days. In both spleen and lymph nodes, the highest representation of IgM(+) lymphocytes occurred between 70 and 86 days gestation. The highest mean percentage of IgM(+) lymphocytes was observed in the spleen (22.63%) and lymph nodes (17.02%) at 75 days gestation. From 98 days onwards, B-lymphocyte density gradually decreased in both spleen and prescapular lymph nodes. This study indicates that substantial populations of IgM(+) lymphocytes were present in both the spleen and prescapular lymph nodes from 70 days gestation and implies that both of these locations could be potential sources for the normal colonization of the ileal Peyer's patches.     

NEMATODE (OTOSTRONGYLUS CIRCUMLITUS) INFESTATION OF NORTHERN ELEPHANT SEALS (MIROUNGA ANGUSTIROSTRIS) STRANDED ALONG THE CENTRAL CALIFORNIA COAST

Between 1 January 1992 and 31 December 1995, 73 of 487 (15%) juvenile northern elephant seals ( Mirounga angustirostris ) that stranded along the central California coastline and were transported to a rehabilitation center had similar clinical signs. These signs included anorexia, depression, dehydration, and epistaxis, and were accompanied by a neutrophilia. Coagulation assays on five of these animals indicated all five were in a state of disseminated intra-vascular coagulation. Sixty-five of the 73 animals died, and post-mortem examination revealed heavy burdens of Otostrongylus circumlitas in the right ventricle and atrium of the hearts and pulmonary arteries, with occasional nem-atodes in the bronchi and bronchioles. Histologic examination of 33 of these seals showed multiple pulmonary thromboses associated with a suppurative arteritis and occasionally intravascular nematodes, suggesting disseminated intravascular coagulation triggered by an arteritis may be important in causing mortality of elephant seals infested with O. circumlitus. This pathology, combined with the observation that death of juvenile northern elephant seals infected with O. circumlitus usually occurs prior to the parasite reaching reproductive maturity, suggests this is a relatively recent host-parasite association.     

Blood viscosity in phocid seals: possible adaptations to diving

1. Mean corpuscular volume (MCV) and mean corpuscular hemoglobin concentration (MCHC) of phocid seal red blood cells (RBC) are elevated compared to those of most terrestrial mammalian species. The influence of these characteristics on blood flow was revealed by viscosity (VIS) measurements. 2. RBC morphology and VIS of whole blood from 7 harbor seals and 5 northern elephant seals were compared with blood of the domestic pig. Samples were analysed for RBC count, white blood cell (WBC) count, total plasma proteins, hematocrit (HCT), MCV and MCHC. Viscosity measurements were made at shear rates from 11.5 to 230.4 s-1 on a Wells-Brookfield cone-plate viscometer at 37 degrees C. 3. Mean values for HCT (%), MCV (micron 3) and MCHC (%) were, respectively: elephant seal: 57, 176, 44; harbour seal: 53, 105, 38; domestic pig: 28, 54, 34. Pig blood was reconstituted to match seal blood HCTs. VIS determinations showed that seal and pig blood conform to the general mammalian dependence of VIS upon shear rate and HCT. 4. Seal blood VIS was 28% (harbour seal) and 16% (elephant seal) less than pig blood VIS at low shear (P less than 0.05). Seal blood carried more hemoglobin per unit volume than did pig blood reconstituted to the same HCT. Fewer, larger RBC with higher MCHC, and hence elevated oxygen storage, accompanied by reduced VIS and reduced flow resistance near stasis suggests that this feature of phocid seal blood is an adaptation to circulatory redistribution during long dives.     

人肝癌原位移植转移模型特性实验研究

目的　建立人肝癌细胞系HCC-9724(简称H)淋巴结转移模型,研究肿瘤转移机理。方法　采用裸鼠肝脏原位移植法,接种肿瘤细胞,取其淋巴结转移灶反复肝内接种,连续传三代后,观察其转移特性,采用SABC法测定淋巴结中nm23和Ⅳ型胶原酶表达。结果　裸鼠原位接种50d,肝内长出约1.7cm×6.0cm大小的肿瘤,呈分叶状,质地较软,周围血供丰富,瘤组织与邻近脏器粘连,有明显的浸润和转移,经裸鼠三次筛选后肿瘤潜伏期短(15d),瘤体大,形成广泛的肠系膜淋巴结转移,淋巴结中Ⅳ型胶原酶表达呈强阳性;而nm23呈弱阳性。结论　采用裸鼠肝原位移植法,反复筛选,获得了人肝癌淋巴结高转移模型。     

Comparative study of the T- and B-cell immunity systems in human and animal embryogenesis

Data are presented on the spleen and thymus structure, time of appearance of the lymphocytes and their heterogeneity in the liver, thymus, spleen, lymph nodes and blood of human foetuses with hemochorial placenta (3 to 34 weeks) and of the minipigs foetuses with epitheliochorial placenta (32 to 95 days). In both foetuses the first T- and B-lymphocytes are found in liver, T-lymphocytes are then found in thymus and later in spleen and lymph nodes whereas B-lymphocytes are found, after liver, in spleen. Kinetics of T- and B-lymphocytes during embryogenesis is described. Reaction of the minipig lymphocytes to mitogens was demonstrated.     

Association of sinus histiocytosis with massive lymphadenopathy and idiopathic hypereosinophilic syndrome

A patient was evaluated because of edema, pruritus and generalized painless lymphadenopathy. Laboratory tests showed marked eosinophilia without known etiology. CT scan of abdomen revealed multiple lymph nodes in retroperitoneal area. Lymph node biopsy was reported as sinus histiocytosis, bone marrow biopsy showed hypercellularity with marked infiltration of normal eosinophils. During his admission he developed Coombs positive hemolytic anaemia. Once he was stable, a laparotomy was performed and the patient died two days later because of septic shock. Autopsy revealed sinus histiocytosis with massive lymphadenopathy (SHML) with extranodal involvement of duodenum, spleen and prostate; septic liver and spleen, pyelonephritis, marked infiltration of eosinophils in lymph nodes, spleen, liver duodenum and lungs. To the best of our knowledge, this is the first case report of the association of SHML and Idiopathic Hypereosinophilic Syndrome (HES).     

超声弹性成像技术对腋窝淋巴结性质的诊断价值

目的:研究超声成像技术对腋窝淋巴结性质的诊断价值。方法:从2013年5月至2014年2月,选择我院50例乳腺癌患者,对所有患者进行弹性成像技术检测出74个腋窝淋巴结。对所有腋窝淋巴结使用四分法进行评分,将其与手术病理结果进行比较。结果:74个腋窝淋巴结中,反应性淋巴结有42个,纵径为(0.9-2.4)cm,平均纵径为(1.31±0.33)cm;乳腺癌腋窝淋巴结转移个数为25个,纵径为(1.2±3.8)cm,平均纵径为(2.04±0.72)cm。良性淋巴结弹性评分大多为1分(54.55%)以及2分(27.27%),恶性淋巴结评分多为3分(63.33%)以及4分(20.00%)。恶性淋巴结评分为(3.12±0.61)分,良性淋巴结评分为(1.68±0.74)分,结果显示,两组淋巴结弹性评分具有较大差异(即P<0.05),具有可比性。结论:综上所述,超声弹性成像技术操作较为简便,效果较为直观,评分法能够提供组织的硬度信息,在临床工作中,与常规超声联合应用有利于提高评价腋窝淋巴结良恶性性质的准确度。值得临床推荐使用。     

Metabolic changes induced by w-3 polyunsaturated fatty acid rich-diet (w-3 PUFA) on the thymus, spleen and mesenteric lymph nodes of adult rats

The maximal activity of key enzymes of glycolysis, pentose phosphate pathway, TCA cycle and glutaminolysis were measured in the immune tissues of rats fed w-3 PUFA during 6 weeks. Total lipid peroxidation and glutathione peroxidase activity were also measured. The hexokinase activity was enhanced 4-fold in the spleen and thymus, doubled in the liver and was diminished in mesenteric lymph nodes (35%). Citrate synthase activity was decreased in the spleen and lymph nodes and increased in the thymus. G-6-PDH activity was increased 2-fold in the spleen and mesenteric lymph nodes and by 20% in the thymus whereas it was reduced (66%) in the liver. Glutathione peroxidase activity and total lipid peroxides increased in all tissues of rats fed w-3 PUFA. The results presented here suggest that w-3 PUFA, by causing important metabolic changes in the immune tissues and lipid peroxidation may lead to changes of immune function.     

Prevalence and characterization of Salmonella spp. among marine animals in the Channel Islands, California

Salmonella enterica is a zoonotic pathogen that has been isolated from free-ranging marine mammals throughout the world, with animals in the Channel Islands of California (USA) showing the highest prevalence. The goal of this study was to determine prevalence, antimicrobial sensitivity and genetic similarity using pulsed-field gel electrophoresis (PFGE) of Salmonella in several non-domestic animal species on San Miguel and San Nicolas Islands. Fecal samples were collected from 90 California sea lion Zalophus californianus pups, 30 northern elephant seal Mirounga angustirostris pups and 87 western gulls Larus occidentalis in the Channel Islands and 59 adult male sea lions in Puget Sound, WA (USA). Salmonella were isolated, identified and serotyped, followed by antimicrobial susceptibility testing and PFGE. Of the California sea lion pups that were sampled on the islands, 21% (n = 19) were positive for Salmonella, whereas no adults males in Puget Sound were positive. Of the northern elephant seal pups sampled, 87% (n = 26) were harboring Salmonella. Only 9% (n = 8) of western gulls were shedding Salmonella, with one of these gulls harboring the only antimicrobial resistant isolate. The serotypes found in these animals were Enteritidis, Montevideo, Newport, Reading, and Saint Paul. The only serotype that showed variation on PFGE was Newport. The pinnipeds of the Channel Islands harbor Salmonella at a higher prevalence than pinnipeds from other geographic areas observed in previous studies. Researchers and veterinarians should exercise increased caution when working with these animals due to the zoonotic potential of Salmonella.     

Reutilization by maternal and embryonal cells of nuclear materials from H3-thymidine labeled lymphocytes introduced into the lumen of intestine of rats

Summary H³-thymidine labeled lymphocytes from thymus and lymph nodes of donor rats were washed and injected in to the intestine of recipient rats on the 11th and 19th day of gestation; subsequent labeling of maternal and embryonal cells was studied autoradiographically 24 hours after injection. In 12-day embryos, numerous stem cells or hemocytoblasts were labeled frequently intensely. In 20-day embryos, stem cells or hemocytoblasts scattered throughout the liver were often labeled. In other fetal tissues at this stage, cells in thymus, spleen, mesenteric lymph node and intestine were labeled but scarcely and weakly. In mothers, labeling in lymphoid tissues was scarce but definite, in thymus, mesenteric lymph node and spleen. These results suggest that nuclear materials from lymphocytes emigrated into the intestinal canal of the mother could be reutilized by maternal and embryonal cells.     

First findings of Cryptosporidium and Giardia in California sea lions (Zalophus californianus)

We report the detection and identification of Cryptosporidium and Giardia from 1 of 3 species of pinnipeds. Fecal samples were collected from Pacific harbor seal (Phoca vitulina richardsi), northern elephant seal (Mirounga angustirostris), and California sea lion (Zalophus californianus) in the northern California coastal area. By means of fluorescently labeled monoclonal antibodies, Cryptosporidium oocysts were detected in 3 samples from California sea lions, 1 of which also contained Giardia cysts. Oocysts of Cryptosporidium and cysts of Giardia were morphologically indistinguishable from oocysts of C. parvum and cysts of G. duodenalis from other animal origins. Oocysts and cysts were then purified using immunomagnetic separation techniques and identified by polymerase chain reaction (PCR), from which species-specific products were obtained. Sequence analysis revealed that the 452-bp and 358-bp PCR products of Cryptosporidium isolated from California sea lion had identities of 98% with sequences of their template fragments of C. parvum obtained from infected calves. Based on morphological, immunological, and genetic characterization, the isolates were identified as C. parvum and G. duodenalis, respectively. The findings suggested that California sea lions could serve as reservoirs in the environmental transmission of Cryptosporidium and Giardia.