Black spot gill syndrome in the northern shrimp, Pandalus borealis, caused by the parasitic ciliate Synophrya sp.

Black spot gill syndrome in the northern shrimp, Pandalus borealis, is caused by an apostome ciliate, Synophrya sp., found within the gill lamellae. Whole mount staining, thin section histology, electron microscopy, and molecular studies were carried out on infected gills. The Synophrya 18S rRNA from Pandalus borealis (Genbank accession no. KX906568) and from two portunid crab species, Achelous spinimanus (Genbank accession no. MH395150) and Achelous gibbesii (Genbank accession no. MH395151) was sequenced. Phylogenetic analyses confirmed the identity of these ciliates as apostomes. The 18S rRNA sequence recovered from P. borealis shared 95% nucleotide similarity with the sequences recovered from the portunid crab species suggesting that it is a different species of Synophrya. The invasive hypertrophont stages, with a distinctive macronuclear reticulum, ranged in size from 300 to 400 µm with as many as 5 large forms/mm2 of gill tissue. Histotrophic hypertrophont stages and hypertomont stages were observed in these studies. The presence of the parasite was linked to the formation of melanized nodules (up to 9 nodules/mm2 of gill tissue) by the host and in some cases to extensive necrosis. Other studies have reported Synophrya sp. infections in P. borealis from Greenland, Labrador and Newfoundland, but further studies are necessary to determine the prevalence of this parasite in the dense schools of northern shrimp in the North Atlantic. Questions remain as to the possibility of epizootics of this pathogen and its impact on northern shrimp populations.

Renal Medullary Carcinoma and Sickle Cell Trait: A Push for Early Diagnosis and Intervention Report of Two Cases.

Renal medullary carcinoma (RMC) is a rare but highly aggressive neoplasm that primarily affects young African Americans with sickle cell trait. Most patients present with macroscopic hematuria and have metastases at diagnosis. Chemotherapy, biologics directed against the more common renal cell carcinomas and radiation have all shown limited efficacy in treating patients with advanced RMC. We report two patients with RMC. Both had Stage IV disease. One underwent radical nephrectomy followed by radiation and biologic drug therapy but died five months later; the other underwent multiple cycles of chemotherapy plus anti-angiogenesis treatment but died 15 months after diagnosis. Review of the literature suggests that early diagnosis and surgical intervention while the tumor is confined to the kidney offer the best prospect for long term survival. Since newborn screening for sickle cell is now mandated in the US, the at-risk population for RMC could be identified and followed by yearly urine dipstick testing for microscopic hematuria. Those who test positive can be further evaluated to rule out RMC.

Toxin-antitoxin loci vapBC-1 and vapXD contribute to survival and virulence in nontypeable Haemophilus influenzae.

BACKGROUND: Nontypeable Haemophilus influenzae (NTHi) is a significant human pathogen responsible for respiratory tract infections and the most common cause of recurrent otitis media. Type II toxin-antitoxin (TA) systems are genetic elements that code for a stable protein toxin and a labile antitoxin that are thought to be involved in metabolic regulation of bacteria by enabling a switch to a dormant state under stress conditions. The contribution to infection persistence of the NTHi TA loci vapBC-1 and vapXD was examined in this study. RESULTS: Deletions in vapBC-1, vapXD and vapBC-1 vapXD significantly decreased the survival of NTHi co-cultured with primary human respiratory tissue at the air-liquid interface and in the chinchilla model of otitis media. The TA deletions did not affect the growth dynamics of the mutants in rich media, their ultra-structural morphology, or display appreciable synergy during NTHi infections. The toxin and antitoxin proteins of both pairs heterodimerized in vivo. Consistent with our previous findings regarding the VapC-1 toxin, the NTHi VapD toxin also displayed ribonuclease activity. CONCLUSIONS: We conclude that the vapBC-1 and vapXD TA loci enhance NTHi survival and virulence during infection in vitro and in vivo using a mechanism of mRNA cleavage, and that these conserved TA pairs represent new targets for the prophylaxis and therapy of otitis media and other NTHi-caused mucosal diseases.

Morphologic effects of in vivo acute exposure to the pesticide methoprene on the hepatopancreas of a non-target organism, Homarus americanus.

Methoprene is a pesticide widely used for mosquito control. It is an endocrine disruptor, acting as an analog of juvenile hormone. While targeting insect larvae, it also impacts non-target animals including crustaceans. Anecdotal reports suggested that methoprene has unintended effects on adult arthropods. Earlier, we documented effects in adult lobsters at the metabolic and gene expression levels. In this study we have documented morphologic corollaries to our prior observations. We examined the light and electron microscopic changes in the hepatopancreas of adult lobsters following in vivo acute exposure to methoprene. Changes by light and electron microscopy levels were evident following exposure to sub-lethal concentrations of methoprene for 24h. Tissue from exposed animals showed the formation of extensive cytoplasmic spaces (vesiculation) with disruption and loss of specific subcellular organelles. The findings provide morphologic correlates to the metabolic and genomic alterations we have observed in previous investigations.

Hyalophysa lynni n. sp. (Ciliophora, Apostomatida), a new pathogenic ciliate and causative agent of shrimp black gill in penaeid shrimp.

The parasitic ciliate causing shrimp black gill (sBG) infections in penaeid shrimp has been identified. The sBG ciliate has a unique life cycle that includes an encysted divisional stage on the host's gills. The ciliature of the encysted trophont stage has been determined and is quite similar to that of the closely related apostomes Hyalophysa bradburyae and H. chattoni. Hyalophysa bradburyae is a commensal ciliate associated with freshwater caridean shrimp and crayfish, while H. chattoni is a common commensal found on North American marine decapods. Based on 18S rRNA gene sequence comparisons, the sBG ciliate is more closely related to the marine species H. chattoni than to the freshwater species H. bradburyae. The unique life cycle, morphology, 18S rRNA gene sequence, hosts, location, and pathology of the sBG ciliate distinguish this organism as a new species, Hyalophysa lynni n. sp.

Transmission of the parasitic dinoflagellate Hematodinium sp. infection in blue crabs Callinectes sapidus by cannibalism.

Infection with the parasitic dinoflagellate Hematodinium sp. can be devastating to blue crab Callinectes sapidus populations. Morbidity and mortality appear to depend on the burden of parasitic organisms. Heavily infected crabs become lethargic and, if not preyed upon, succumb to overwhelming infection. We report on the transmission of Hematodinium sp. into blue crabs that were fed pieces of infected tissues and examined for evidence of infection at time periods from 1 to 48 h and for the general state of their health after 4 d. During the first 16 h after feeding, Hematodinium sp. was found in the gut, followed by large increases in hemolymph hemocytes and the appearance of hemocytic nodules in tissues. By 16 h, the hemocytic nodules appeared poorly circumscribed and disorganized. No nodules were seen in a heavily infected crab after 24 h. By the end of the 48 h after feeding, 73% (11 of 15) of the crabs had shown evidence of infection with Hematodinium sp. Those crabs with infection intensities (Hematodinium sp. as percent of cells in hemolymph) higher than 20% were dead within 4 d.

Cutaneous Rosai-Dorfman disease of the forearm: case report.

Sinus histiocytosis with massive lymphadenopathy, also known as Rosai-Dorfman disease (RDD), is a rare non-neoplastic pathologic condition that frequently pursues a prolonged clinical course marked by exacerbations and remissions. Cutaneous RDD is even less common than cases involving lymph nodes. We present the case of a patient with long-standing Crohn's disease who developed cutaneous RDD in the forearm.

Endoplasmic Reticulum Stress Enhances Mitochondrial Metabolic Activity in Mammalian Adrenals and Gonads.

The acute response to stress consists of a series of physiological programs to promote survival by generating glucocorticoids and activating stress response genes that increase the synthesis of many chaperone proteins specific to individual organelles. In the endoplasmic reticulum (ER), short-term stress triggers activation of the unfolded protein response (UPR) module that either leads to neutralization of the initial stress or adaptation to it; chronic stress favors cell death. UPR induces expression of the transcription factor, C/EBP homology protein (CHOP), and its deletion protects against the lethal consequences of prolonged UPR. Here, we show that stress-induced CHOP expression coincides with increased metabolic activity. During stress, the ER and mitochondria come close to each other, resulting in the formation of a complex consisting of the mitochondrial translocase, translocase of outer mitochondrial membrane 22 (Tom22), steroidogenic acute regulatory protein (StAR), and 3ß-hydroxysteroid dehydrogenase type 2 (3ßHSD2) via its intermembrane space (IMS)-exposed charged unstructured loop region. Stress increased the circulation of phosphates, which elevated pregnenolone synthesis by 2-fold by increasing the stability of 3ßHSD2 and its association with the mitochondrion-associated ER membrane (MAM) and mitochondrial proteins. In summary, cytoplasmic CHOP plays a central role in coordinating the interaction of MAM proteins with the outer mitochondrial membrane translocase, Tom22, to activate metabolic activity in the IMS by enhanced phosphate circulation.

Small-cell undifferentiated carcinoma of neuroendocrine type originating in the gallbladder.

PURPOSE: We report a case of small-cell undifferentiated carcinoma with neuroendocrine (SCUCN) of the gallbladder in a 67-year-old man who presented with suspected cholelithiasis. Treatment included a cholecystectomy and a 4-cycle course of etoposide and carboplatin. CONCLUSIONS: Small-cell undifferentiated carcinoma with neuroendocrine features of the gallbladder is a rare disease with approximately 30 cases reported in the literature. Clinical characteristics include an association with cholelithiasis, an elderly age distribution, a female preponderance, and a correlation with cigarette smoking. It is known to behave aggressively and carry a grave prognosis, with extensive local invasion and early metastasis being characteristic. Medical and surgical therapies exist and have demonstrated best results when used in combination.

Pesticide induced alterations in gene expression in the lobster, Homarus americanus.

Using subtractive hybridization, we have identified 17 genes that are either up- or down-regulated in the hepatopancreas (Hp) of the lobster, Homarus americanus, by acute exposure to the juvenile hormone analog methoprene. The expression of some of the genes obtained from the subtraction libraries was confirmed by real time Q-PCR experiments. These genes encode several different classes of proteins including: structural, enzymatic and regulatory polypeptides. Enzymes represent the predominant genes up-regulated by methoprene. Included in this group are betaine-homocysteine S-methyltransferase (BHMT) and two other enzymes of the methionine cycle. Increased expression of a translation factor (eIF2), as well as of cytosolic (aldose reductase), structural (beta-tubulin, L5A) and plasma membrane (CD42d) proteins was observed. In addition, a major feature of altered gene expression in methoprene treated Hp was increased levels of enzymes associated with protein turnover, including trypsin, ubiquitin conjugating enzyme and ubiquitin carboxyl terminal hydrolase. Down-regulation of the members of the hemocyanin family was observed. Assays confirmed elevated levels of trypsin in the Hp of lobsters after 24 h exposure to methoprene. Our findings suggest a wide variety of cellular targets are altered by methoprene.

Hedgehog signaling and cell cycle control in differentiating erythroid progenitors.

Hedgehog (Hh) signaling regulates differentiation in numerous systems, but its functions in the control of hematopoietic differentiation have not been extensively explored. Initial studies have indicated that hedgehog signaling affects the proliferation and differentiation of erythroid progenitors (Detmer, K., et al., Erythroid differentiation in vitro is blocked by cyclopamine, an inhibitor of hedgehog signaling. Blood Cells Mol. Dis. 26(4) (2000) 360-372). To examine the effect of Hh signaling on the erythroid developmental program at the molecular level, Hh signaling in committed erythroid progenitors differentiating in vitro was inhibited, and the appearance/disappearance of molecular markers of erythroid differentiation was monitored. The expression timetable for CD34, CD36, the erythropoietin receptor, and glycophorin A was retarded in the absence of Hh signaling. Hemoglobinization was delayed and decreased relative to controls. Morphological changes of erythroid maturation were also delayed. The fraction of cells in S-phase was decreased during the initial period of exponential expansion as assessed by propidium iodide staining and flow cytometry, as was the rate of tritiated thymidine incorporation. A modest decrease in the proliferation rate was observed. These results suggest that Hh signaling is one of the mechanisms in the regulation of erythroid proliferation and differentiation.

Bioaccumulation and Metabolic Effects of the Endocrine Disruptor Methoprene in the Lobster, Homarus americanus.

Methoprene is a pesticide that acts as a juvenile hormone agonist. Although developed initially against insects, it has since been shown to have toxic effects on larval and adult crustaceans. Methoprene was one of several pesticides applied to the Western Long Island Sound (WLIS) watershed area during the summer of 1999; the other pesticides were malathion, resmethrin, and sumethrin. These pesticides were applied as part of a county-by-county effort to control the mosquito vector of West Nile Virus. Subsequently, the seasonal lobster catches from the WLIS have decreased dramatically. The lethality of the pesticides to lobsters had been unknown. We studied the effects of methoprene while other investigators studied effects of the other pesticides. We questioned whether methoprene, through its effects on larvae, adults or both, could have contributed to this decline. We found that low levels of methoprene had adverse effects on lobster larvae. It was toxic to stage II larvae at 1 ppb. Stage IV larvae were more resistant, but did exhibit significant increases in molt frequency beginning at exposures of 5 ppb. Juvenile lobsters exhibited variations in tissue susceptibility to methoprene: hepatopancreas appeared to be the most vulnerable, reflected by environmental concentrations of methoprene inhibiting almost all protein synthesis in this organ.Our results indicated that methoprene concentrates in the hepatopancreas, nervous tissue and epidermal cells of the adult lobster. Methoprene altered the synthesis and incorporation of chitoproteins (cuticle proteins) into adult postmolt lobster explant shells. SDS PAGE analyses of adult post-molt shell extracts revealed changes in the synthesis of chitoproteins in the methoprene-treated specimens, suggesting that methoprene affects the normal pathway of lobster cuticle synthesis and the quality of the post-molt shell. Although it is likely that a combination of factors led to the reduced lobster population in WLIS, methoprene may have contributed both by direct toxic effects and by disrupting homeostatic events under endocrine control.

Bone morphogenetic proteins act synergistically with haematopoietic cytokines in the differentiation of haematopoietic progenitors.

We examined the effects of bone morphogenetic protein-2 (BMP-2), -3, -4, -5, -6, and -7 on the proliferation and differentiation of bone marrow CD34+ haematopoietic progenitors in semi-solid medium. The BMPs had no effect on haematopoietic colony development when added to medium containing erythropoietin (Epo) or Interleukin-3 plus Epo. Synergistic effects with the haematopoietic cytokines stem cell factor (SCF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) were observed. In conjunction with GM-CSF and Epo, BMP-4 increased the number of both erythroid and granulocyte/monocyte colonies formed in semi-solid medium (P<0.01). No other BMP stimulated erythroid colony development under these conditions, while BMP-3, BMP-7 (P<0.01), BMP-5, and BMP-6 (P<0.05) stimulated granulocyte/monocyte colony formation. BMP-7 acted synergistically with stem cell factor to increase granulocyte/monocyte colony formation but not erythroid colony formation. The other BMPs did not affect either erythroid or granulocyte/monocyte colony development under these conditions. These results suggest that individual BMPs form part of the complement of cytokines regulating the development of haematopoietic progenitors, and in particular, point to a role for BMP-4 in the control of definitive, as well as embryonic erythropoiesis.

Cutaneous sclerosing extramedullary hematopoietic tumor in chronic myelogenous leukemia.

BACKGROUND: Extramedullary hematopoiesis is a well-documented manifestation of chronic myeloproliferative disorders, most commonly seen in chronic idiopathic myelofibrosis (agnogenic myeloid metaplasia), but rarely in chronic myelogenous leukemia. It typically occurs in the spleen and liver, but has also been described in skin. Microscopically, foci of extramedullary hematopoiesis consist of erythroid and myeloid precursors intermixed with megakaryocytes. The megakaryocytes may elaborate fibrogenic cytokines, which induce proliferation of fibroblasts. The term 'sclerosing extramedullary hematopoietic tumor' has been applied to this latter entity and its resemblance to a fibrohistiocytic neoplasm has been noted. METHODS: We report the case of a 66-year-old man, whose cutaneous sclerosing extramedullary hematopoietic tumor preceded the diagnosis of chronic myelogenous leukemia.