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A diploid chromosome number of 20 (n = 10) was found for each of the native oyster Ostrea lurida, and the Pacific oyster Crassostrea gigas. The diploid complements of the native oyster were normal but in the Pacific oyster atypical numbers, polyploid nuclei, and abnormal cleavage was observed in some somatic metaphase plates. The diplotene meiotic bivalents of the native oyster resembled lampbrush chromosomes.

Degeneration of the digestive tubules following irradiation with 20 Krads is briefly described. Epithelial denudation is the ultimate observable manifestation. All normal epithelial cells, i.e., crypt or generative cells, secretory and absorptive cells, are sloughed and only an abnormal squamous cell lining remains. Cell repopulation or regeneration begins with the formation of cell nests or epithelial islands through mitotic division of either uninjured or repaired crypt cells, or possibly both. Subsequent migration of these cells from the islands ultimately results in reepithelization of the tubule.

This study describes the histopathology and the associated gross pathological alterations of experimentally induced acute inflammation in the oyster, Crassostrea gigas, after turpentine injections into two different tissues, the adductor muscle and the Leydig cell area. Under optimum conditions the oyster can successfully combat a toxic substance such as turpentine, with the adductor muscle being more capable of handling such an irritant than the Leydig cell area. Inflammation in vertebrates is compared with that in the oyster.

Oysters were irradiated at the following levels: 0, 1, 5, 10, 20, 50, 100, 200, and 400 Krads using gamma radiation from a cobalt source. Mortalities began to appear 4 days after irradiation in the 200- and 400-Krad groups and, with one exception, all oysters in these two groups were dead after 11 days. This report describes three histopathological syndromes involving the degeneration of digestive tissues (digestive tubules, collecting ducts, stomach, and gut): an acute, lethal syndrome of oysters irradiated with 200 and 400 Krads; an acute, sublethal syndrome of oysters irradiated with 10, 20, 50, and 100 Krads and a subacute, sublethal syndrome of oysters irradiated with 1 and 5 Krads. These syndromes are compared with the gastrointestinal radiation syndrome of mammals.

Ciliates of the order Thigmotrichidia were observed to heavily infect Pacific oysters (Crassostrea gigas) that possessed weakened adductor muscles. A description of the ciliates, the method of infection, and the pathology associated with these ciliates is presented.

A study was made of the wound repair process of the Pacific oyster, Crassostrea gigas . It was observed that the healing process is carried on in its entirety by the leukocytes of the injured organism. These cells delineate the wound, enclose and fill the lesion and ultimately, after scar formation, remove the damaged tissues and transform into new cells indistinguishable from normal cells of the oyster. The wound-healing process of the oyster is compared with the same process in other invertebrate groups.

Postlarval, early, and late juvenile stages of two species of penaeid shrimp, Penaeus aztecus Ives and P. setiferus (L.), were tested for susceptibility to a nuclear polyhedrosis virus from Autographa californica (Speyer). Shrimp were exposed to the virus by intramuscular inoculation of polyhedral protein-free virus and by feeding a diet containing virus polyhedra. Mortality attributable to viral infection did not occur dunng the 30-day test period, nor was there histological evidence of viral activity in shrimp hepatopancreas, gut, gill, striated muscle, ventral nerve, and segment nerve ganglia, or hypodermis.

Bacteriological investigations of dead and dying oysters in populations of Crassostrea gigas grown in Hood Canal, Oyster Bay, and Willapa Bay, Washington, were undertaken. Living, and presumably normal, oysters within the same sample set were also examined. Results indicated that the natural flora of Crassostrea gigas (Thunberg) is composed of organisms representing the genera Pseudomonas, Achromobacter, Flavobacterium , and Vibrio . Pollution indicator organisms such as Escherichia coli were not found. The flora of dead or dying oysters included a somewhat greater incidence of Pseudomonas sp.; a seawater-requiring organism isolated on several occasions from oyster gapers which had been collected from different geographical areas was identified as P. enalia . A description of the organism has been provided, and the characteristics are listed to facilitate identification by other workers encountering the organism in future studies of a similar kind. The seawater requirement exhibited by P. enalia was deduced to be a requirement for sodium chloride for growth of the organism. Experiments to determine the pathogenicity of Pseudomonas enalia were performed by use of experimentally infected animals maintained in aerated seawater tanks. Death of C. gigas occurred when the animal body tissue was injected with viable bacterial cell suspension. Results of histological studies of the normal and infected oyster tissue suggest that bacterial invasion of the tissue occurred. Images Fig. 1 Fig. 2

The present study was initiated to study the acute inflammatory process in the oyster, Crassostrea gigas (Thunberg), elicited by injection of turpentine into the tissues. Gross examination revealed a small greenish-yellow area of pus present in all oysters 40 hours after the injection. Histologically, the various pathological changes observable after the injection of turpentine were edema, a general leucocytic infiltration of the tissues, and congestion of the small blood channels after 8 hours. By 16 hours there was a marked vascular dilatation with pavementing of the larger vessel walls by leucocytes and a cellular exudation and migration of leucocytes toward the source of irritation at 24 hours. A thick wall of leucocytes around the wound was characteristic after 48 hours. The appearance of multinucleate giant cells began at 64 hours, as did the mass migration of leucocytes across the epithelial borders of the digestive system. By 72 hours, the digestive tubule secretory epithelium was reduced to a low cuboidal epithelium. At this time pus was becoming a prominent feature in the injured area. Necrotic changes in the gonadal area associated with edema, heavy leucocytic infiltration, distention of the gonadal ducts, and walls of leucocytes forming around the necrotic gonadal areas were observed 72 hours after injection. A distinct abscess was first observed after 88 hours and abscesses were found in almost all oysters from 88 hours through 216 hours. The consistent characteristics of the abscesses were a central area of liquefaction necrosis, surrounded by an area of necrotic leucocytes, with an area of viable appearing leucocytes around the periphery of the lesion. The abscesses were usually in the digestive tubule area and in most instances appeared well confined, even though they lacked any observable signs of fibrous encapsulation. Some oysters exhibited an ulceration of the stomach or intestinal lining. This phenomenon was not observed before 88 hours after injection, the same time at which abscesses were first noticeable.

Leeches were wounded in the posterodorsal area by nonsterile incision. Initial response consists of bodily contraction and localized constriction, resulting in the forcing of injured tissue and debris toward the lesion and the expelling of some of the debris to the exterior. Undifferentiated cells immigrate into the area and form a connective tissue plug incorporating the remaining debris. The debris is expelled by a continuous sloughing of the outer plug cells, while recruitment of additional immigrating cells replenishes the plug. A weak phagocytic response is noted if a major coelomic channel is severed. After the wound is cleared of debris, the connective tissue mass is covered by migration of adjacent epithelial cells. No additional repair occurs for at least the following 6 days, and only a scar remains.

The bay mussel Mytilus edulis (Linnaeus) and the California sea mussel Mytilus californianus (Conrad) have a common diploid chromosome number 28 (n = 14) that is, there were 14 bivalents during meiosis and 28 chromosomes during mitosis. A total of 35 specimens of the two species were examined from several intertidal locations in Puget Sound and the Northwest Pacific coast of the United States. The number of meiotic bivalents in stripped or spawned eggs was always constant but aneuploid counts of mitotic chromosomes were made in cleaving eggs and embryos. Heteromorphic bivalents in meiotic plates and heteromorphic homologues in mitotic karyotypes were observed. The number of metacentric, submetacentric and acrocentric chromosomes was variable. There were 2 to 6 pairs of acrocentrics in different complements. This polymorphism indicates the existence of pericentric inversions or centric-shifts in both meiotic and mitotic chromosomes.

This study is an extension of previous work performed by Pauley and Sparks to describe and understand more thoroughly the histopathology associated with experimental injuries in the Pacific oyster, Crassostrea gigas . Descriptions are given of the effect of talc injections into two different tissues of the oyster, the adductor muscle and the Leydig cells. The oyster possesses the ability to successfully combat a nontoxic substance such as talc, with the adductor muscle more capable of effectively repairing wounds made by such a foreign body than are the Leydig cells. A description of open and healed surface ulcerations found on the oyster mantle is given. Discussion of the repair process is given for mollusks, other invertebrates, and vertebrates.

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The autopsy of a man who died of Hodgkin disease revealed that a peculiar metazoan parasite had proliferated and disseminated throughout his body. The parasite could not be identified; however, electron microscopical studies revealed that it had the structure of a flatworm. This, together with its shape and structure, convinced us that the parasite was an aberrant sparganum manifesting uncontrolled proliferation and dissemination.

Polarized protons have been used to measure the analyzing powers for the reaction 59CO(p,γ)*0Ni leading to the first excited 2+ state of 60Ni in the region of the giant dipole resonance. The extracted a2 and b2 coefficients are compared to a direct‐semidirect calculation.

An adult female red king crab, Paralithodes camtschatica , collected in the Kodiak Management area in 1985 contained, on necropsy, a grossly recognizable lesion. The lesion presented as a white lump, 20 × 12 mm, attached to the ventral side of the anterior-most hindgut. Microscopically, the lesion consisted mostly of large pleomorphic epithelioid cells with slightly basophilic cytoplasm and markedly hypertrophied nuclei. The chromatin was sparse, beaded, and positioned marginally and around the nucleolus. The nucleolus was prominent, slightly basophilic, and amorphous. The nuclei were frequently irregularly shaped and multiple nucleoli were common. The epithelioid cells formed swirling crypts or nests within the wall of the hindgut. The putative tumor was unencapsulated but somewhat circumscribed in some areas. Growth was diffusely infiltrative in some areas, but massively invasive in others. The lesion was accompanied by a massive hemocytic, especially eosinophilic granulocyte, response. There were numerous apparent attempts to encapsulate small groups of “tumor” cells and some individual abnormal cells were phagocytosed by eosinophilic granulocytes. The lesion appears to be clearly neoplastic, markedly anaplastic, and poorly differentiated. Possible origins are discussed.

In the enzyme-linked immunosorbent assay (ELISA), antibody dilution curves of immune sera from different individuals often reach plateaus or an initial flat phase at different absorbance (OD) levels. Two experimental models are presented as possible mechanisms for plateau formation. In both models it is assumed that the immune sera have sufficient quantities of antibody of similar affinity to saturate the antigenic determinants on the solid phase. In the first model specific antisera to two pure antigens, hemoglobin and transferrin, produced dose-response curves with separate plateau levels in ELISA. The comixture of these two antisera produced a plateau level which was equal to the sum of the plateau absorbance for each antigen. In the second model, dose-response curves were generated using immune sera with cross-reacting antibodies to a pure multivalent antigen (bovine serum albumin). Plateau regions at different absorbances were demonstrated which correlated with the degree of cross-reactivity of the antisera and the number of antigenic determinants recognized by antibody specificities in the immune sera. These models suggest that the initial plateau regions of the ELISA dose-response curve represents the summation of antibody specificities in an immune serum to some or all of the antigenic determinants of a complex antigen(s) bound to the solid phase. A new approach to the quantitation of antibody concentrations by ELISA is described.

Angular distributions of I(2P3/2) scattered off Kr and Xe(1S0) in the thermal energy range have been measured in crossed molecular beams experiments. The interaction potentials for two relevant states (X 1/2 and I 3/2) for each of the systems are obtained by using an approximate elastic scattering analysis, which neglects nonadiabatic coupling, as previously done for other rare gas–halogen systems. The I–Xe (X 1/2) potential (e = 0.69 kcal/mol, rm = 4.30 A) and, to some extent, I–Kr (X 1/2) potential (e = 0.55 kcal/mol, rm = 4.05 A) shows a slightly more attractive interaction than the interaction potentials of Xe–Xe and Xe–Kr, but the I–Xe (I 3/2) potential (e = 0.48 kcal/mol, rm = 4.60 A)) and the I–Kr (I 3/2) potential (e = 0.36 kcal/mol, rm = 4.32 A) present shallower e’s, a larger rm, and stronger repulsive walls than the corresponding rare gas pair potentials. The results obtained from this and previous investigations are reviewed.

A sensitive immunoassay for detecting acetaminophen (APAP) bound to proteins was developed using an affinity purified antibody directed against the N-acetylated end of the APAP molecule. Western blots of electrophoretically resolved liver proteins taken from mice given an hepatotoxic dose of APAP demonstrated that nearly 85% of the total detectable protein-bound APAP was covalently associated with proteins of 44 and 58 kD. Pretreatment of liver extracts with the sulfhydryl-specific reagent, N-ethylmaleimide (NEM), prior to derivatization with the reactive metabolite of APAP, N-acetyl-p-benzoquinone imine (NAPQI), greatly reduced immunochemically detectable APAP-protein adducts and indicated that the antibody detects protein-thiol conjugates of APAP. To investigate the basis of the binding selectivity in vivo, a variety of systems which yielded APAP-protein adducts were analyzed. Systems which activate APAP enzymatically, as in hepatocyte suspensions or in post-mitochondrial (S9) fractions fortified with an NADPH-regenerating system, resulted in a protein binding profile similar to that produced in vivo. Conversely, when extracts or cells were treated with chemically synthesized NAPQI, an alternative protein binding profile was obtained. Two-dimensional electrophoretic analysis of the reduced protein thiol (PSH) content of liver proteins using [3H]NEM labeling revealed that the 58 kD APAP-binding proteins were rich in PSH, whereas the major 44 kD binding protein had virtually no detectable PSH. Many PSH-rich proteins that were not arylated in vivo did bind NAPQI in vitro. However, the 44 kD proteins were not arylated when chemically synthesized NAPQI was added to homogenates or cell suspensions. The present data further suggest that, in addition to the amount and reactivity of free protein sulfhydryls, the cellular localization with respect to the cytochrome P-450 activation site may influence the susceptibility of proteins to NAPQI binding. These findings signal the need for caution in interpreting studies of APAP mechanisms that rely solely on NAPQI addition.

The singlet–triplet splitting in methylene has been determined from the measurements of fragment velocities from ketene photodissociation at 351 and 308 nm in a molecular beam. The splitting is found to be 8.5±0.8 kcal/mol. This agrees with many experimental results, but not with the value of 19.5 kcal/mol derived from recent photodetachment experiments on CH−2.

Reactions of F + H2, D2 have attracted extensive theoretical and experimental attention in recent years and will undoubtedly become one of the prototype chemical reactions in the future for the detailed understanding of reaction dynamics through meaningful comparison between theoretical calculations and experimental observations.

LBL-12309 c ,.;L Preprint Lawrence Berkeley Laboratory UNIVERSITY OF CALIFORNIA Materials & Molecular Research Division Submitted to the International Journal of Chemical Kinetics ON THE PHOTODISSOCIATION OF NITROMETHANE AT 266 nm H.S. Kwok, G.Z. He, R.K. Sparks, and Y.T. Lee February 1981 I.AWRE! ·M.:E :::::!':I.EY LABuRAl'OP.., APH 'r' TWO-WEEK LOAN COPY a Library Circulating Copy which may be borrowed for two weeks. For a personal retention copy} call This is Tech. Info. Division} Ext. 6782. Prepared for the U.S. Department of Energy under Contract W-7405-ENG-48

White shrimp, Penaeus setiferus, infected by the plerocercoid larva of the trypanorhynchid cestode, Prochristianella penaei, respond to infections in the heptaopancreas by developing a progressively denser cyst, composed of hemocytes, fibroblasts, and collagenlike fibers, around the parasite. The pleocercoid is eventually destroyed and resorbed leaving a dense fibrous capsule in the hepatopancreas. Worms in the adjacent hemocoel are encapsulated by a thin host cyst and a less intense infiltration of cells and deposition of fibers, insufficient to destroy the pleroceroid. It is believed that the resorption process explains the drop in intensity of infection in juvenile white shrimp after a certain size is attained.

A Pacific oyster, Crassostrea gigas , with multiple watery cysts was examined histologically and found to possess an unusual proliferation of tissue. The proliferative growth, thought to be a ganglioneuroma, had replaced much of the normal tissue and was accompanied by an intense inflammatory reaction. The cause of the neural lesions and their relationship to the watery cysts is unknown.

A study was made of the host reaction of the Pacific oyster, Crassostrea gigas , to intraspecific living tissue implants. A number of the implants were rejected by the host; but those that remained within the host appeared normal throughout the experiment. Although the implants appeared to inhibit wound healing, the process ultimately followed the typical pattern for the species. Leucocytes delineated the wound and formed a union with the implants. Finally, the implants fused with the host and became contiguous with it.

A brown shrimp, Penaeus aztecus, from an experimental pond of the Texas Parks and Wildlife Department's Marine Laboratory at Palacios, Texas, possessed a papilliform tumorlike growth on the right ventrolateral aspect of the sixth abdominal segment. Gross and histological study revealed the lesion to be confluent with the carapace, epidermis, and subepidermal connective tissue. The growth, tentatively diagnosed as a benign neoplasm, consists of grossly hypertrophied and normal tissue elements.