Flow cytometric comparison of haemocytes from three species of bivalve molluscs

Haemocyte subpopulations from three bivalve species (the clams Ruditapes philippinarum and Mercenaria mercenaria and the oyster, Crassostrea virginica) were characterised using light-scatter flow cytometry and a standard set of methods. Two parameter (forward and side scatter) plots for the three species were very similar and resembled plots for mammalian white blood cells. Two haemocyte groups (granulocytes and agranulocytes) were found in both the haemolymph and the extrapallial fluid of the clams while those two groups and an additional third group were found in the haemolymph of the oyster. All subpopulations were sorted on to glass slides, identified, photographed, and measured microscopically. Sorting of the bivalve granulocyte and agranulocyte groups indicated varying degrees of heterogeneity within each population in terms of either size or granularity, or both. However, subsorting of selected regions within the major groupings produced highly pure haemocyte populations. The comparison showed both similarities and differences among species. For instance, a distinct subpopulation of small granulocytes was present only in oysters and a subpopulation of spindle-shaped haemocytes, only in M. mercenaria. The haemocyte subpopulations delineated by light-scatter flow cytometry underscore questions about cell lineages, but the instrument also offers a powerful technique for answering them.

Fatal hypertrophic cardiomyopathy in the fetus of a woman with diabetes

BACKGROUND

Hypertrophic cardiomyopathy is recognized in infants of diabetic mothers, and when it occurs it is generally benign and transient. We describe a case of fetal cardiac death caused by hypertrophic cardiomyopathy in an infant of a diabetic mother.

CASE

Hydrops fetalis caused by hypertrophic cardiomyopathy resulted in the death of a macrosomic male fetus of a young woman who had well-controlled diabetes mellitus and was treated with insulin therapy during pregnancy.

CONCLUSION

It is important to monitor fetal heart function in macrosomic infants of diabetic mothers. Hypertrophic cardiomyopathy might explain otherwise unexplained fetal deaths in women with diabetes.

Epizootiology and pathology of juvenile oyster disease in the Eastern oyster, Crassostrea virginica

Juvenile Oyster Disease (JOD) causes mortalities of small cultured oysters, Crassostrea virginica. The present study was an intensive epizootiological and pathological investigation of JOD in eight sequentially deployed cohorts at sites on Long Island, New York. JOD symptoms and mortalities began in all groups at about the same time. Lesions on the mantle were detected histologically about 1 week before the principal symptom, a conchiolin deposit on the inner shell, appeared. Mortality began about 1 week later and reached 60-90% in oysters <25 mm. Mantle lesions were highly correlated with subsequent conchiolin-deposit prevalence and with total mortality. Larger juveniles (25-40 mm) were affected by the disease and produced conchiolin deposits, but mortalities did not exceed 30%. Mortalities were consistently related to size, but not necessarily to age or length of "exposure" in the field. There was no indication that JOD was linked to a particular broodstock or hatchery. Wild spat deployed at experimental sites showed JOD symptoms before the hatchery-produced groups did and cohorts maintained inside a hatchery experienced essentially no JOD. Histological examination of cohorts experiencing high mortalities failed to reveal an obvious etiological agent, but showed a disease pattern similar to that described for other bivalve diseases with a bacterial etiology. Similarities and differences between this and other studies of JOD suggest that one or more bacterial species is responsible for JOD, but that a trigger, probably temperature, is also involved and may vary from site to site.

Haemocyte parameters associated with resistance to brown ring disease in Ruditapes spp. clams

Brown ring disease (BRD) is a shell disease caused by Vibrio tapetis. This pathogen disturbs the periostracal lamina causing the appearance of a brown conchiolin deposit on the inner face of the shell, within the extrapallial space. Although differences in resistance to BRD have been documented, their relationship to possible defense functions has never been investigated. In this study, flow cytometry was used to analyze cellular parameters in asymptomatic and experimentally infected Ruditapes philippinarum from France and the west coast of the USA. Parallel analyses were made on Ruditapes decussatus, the native European clam, which is highly resistant to BRD. In the haemolymph and extrapallial fluid of animals without BRD, total haemocyte counts, the percentage of granulocytes, and the phagocytic activity against latex beads or V. tapetis by the haemocytes were significantly higher in American R. philippinarum than in French R. philippinarum. In most cases, levels in R. decussatus were the highest of all three groups. Four weeks following challenge with V. tapetis, BRD prevalence reached 52 in American clams and 100% in French specimens, but only 37% in R. decussatus. In symptomatic animals, phagocytosis of V. tapetis increased significantly in the resistant species of clam, R. decussatus, was unchanged in US clams, and decreased significantly in FR specimens when compared to asymptomatic individuals from each population. Ingestion of V. tapetis by haemocytes in the extrapallial fluid, which is in contact with the periostracal lamina, could be the main defense mechanism used to counter the pathogen. Our results suggest that resistance to BRD may well be related to the concentration of granular haemocytes and the phagocytic activity of haemocytes.

The Effect of Music on the Self-Injurious Behavior of an Adult Female with Severe Developmental Disabilities

This study compared the effects of contingent blocking, music listening, water play, and instrument playing on self-injurious behavior. The subject was a 23-year-old female with severe developmental disabilities, including communication deficits, motor deficits, and visual impairment. A single subject reversal design with four conditions (ABACADA) was used. Subject was videotaped 10 minutes before and 10 minutes after the interventions to study changes in rate and variability of three behaviors: teeth-grinding, mouth-scratching, and head-hitting. Visual analysis showed a strong downward trend after music listening for teeth-grinding, and no change over all conditions for mouth-scratching. Subject did not exhibit any preintervention head-hitting during both music conditions, and therefore showed no change in behavior. Subject responded to water play and contingent blocking by reducing head-hitting.

Congenital cystic tumors of the atrio-ventricular node: successful demonstration by an abbreviated dissection of the conduction system

Pathologists are dissuaded from the pathological study of the conduction system by the high cost and complexity of a traditional complete study. However, a simplified, low-cost approach can produce concrete information when performed in carefully selected cases of atrioventricular block, as demonstrated in the two cases of congenital cystic tumor of the atrioventricular node described in this report.

Thrombotic thrombocytopenic purpura as an initial presentation of limited systemic sclerosis

Thrombotic thrombocytopenic purpura (TTP) is a rare complication of scleroderma (systemic sclerosis, SSc). In the 5 reports documenting the association of TTP and SSc, the TTP syndrome developed on a background of well established SSc. We describe a 51-year-old woman with a 5 month history of an evolving connective tissue disease syndrome who presented initially with TTP, followed 4 months later by limited cutaneous SSc and Raynaud's phenomenon.

In vivo dynamics of the microparasite Perkinsus marinus during progression and regression of infections in eastern oysters

We used a total body parasite burden assay for the oyster pathogen Perkinsus marinus to investigate quantitative changes in microparasite burdens and frequency distributions. Heretofore, this type of study was limited mainly to macroparasites. The apparent in vivo growth pattern of P. marinus was characterized by a "lag" phase (< 10 cells/g wet weight [g wwt], a "log" phase (10-10,000 cells/g wwt), and a "stationary" phase (> 10,000 cells/g wwt). Infections declined exponentially under conditions unfavorable to the parasite but with a lengthening half-life, suggesting that elimination of parasites became increasingly difficult at low densities. Oysters held for 11 wk at 15 C, a temperature considered more favorable for oyster hemocytes than for P. marinus, were not able to eliminate infections. Parasite distributions within host populations were aggregated; in each sample, 1 or 2 oysters contained more parasites than all other oysters in the sample combined and the variance-to-mean ratio exceeded 1:1. The few hosts with large parasite burdens may be the most important individuals for survival and transmission of parasites. They are likely to play a key role in initiating and maintaining epizootics either in situ or after introduction of infected animals into a naive population.

A PCR-ELISA Method for Direct Detection of the Oyster Pathogen Haplosporidium nelsoni

: A rapid method, utilizing both polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA), was developed for detection of oyster MSX disease. The technique included using Haplosporidium nelsoni pathogen-specific PCR primers (based on ribosomal RNA genes), a Chelex resin (for rapid DNA extraction from oyster mantle tissues), and cloned H. nelsoni rRNA plasmid DNA (for use as a capture probe). Digoxigenin was incorporated into the pathogen-specific PCR products, which were captured by the coated probe in a fast hybridization reaction and then detected by ELISA. The sensitivity of PCR amplification on cloned plasmid DNA was 10 fg for detection by stained agarose gel, and increased to 0.01 fg for ELISA. Positive signals were observed in infected oysters using the PCR-ELISA technique. This method may be applicable to early detection of infection.

Perkinsus marinus tissue distribution and seasonal variation in oysters Crassostrea virginica from Florida, Virginia and New York

Perkinsus marinus infection intensity was measured in eastern oysters Crassostrea virginica collected in October and December 1993, and March, May, and July 1994 from 3 U.S. sites: Apalachicola Bay (FL), Chesapeake Bay (VA), and Oyster Bay (NY). Gill, mantle, digestive gland, adductor muscle, hemolymph, and remaining tissue (including gonadal material and rectum) were dissected from 20 oysters from each site at each collection time. Samples were separately diagnosed for P. marinus infections by incubation in Ray's Fluid Thioglycollate Medium (RFTM) and subsequent microscopic quantification of purified enlarged hypnospores. At all sampling times and sites, average P. marinus infection intensity (g wet wt tissue-1 or ml hemolymph-1) was lowest in hemolymph samples, and generally highest in the digestive gland. Perkinsus marinus prevalence was 100% at both FL and NY sites for each of the 5 collection times, and, for the VA site, was less than 100% in only 1 month (May 1994). Seasonal intensity patterns and mean total body burdens differed among the sites. Average body burden was highest in VA during October and progressively declined to a minimum in May. This decline was probably due to mortality of heavily infected oysters and diminution of parasite activity associated with colder temperatures and reduced salinities. Intensities varied little during the months of October and December at both the FL and NY sites. Minimum average intensities were observed in March in FL oysters and May in NY oysters. Relatively high P. marinus infection levels that persisted throughout the winter in NY oysters compared with VA oysters could reflect constant high salinity in Long Island Sound which favors parasite activity, and also rapid decline in temperature in the fall that may have prevented epizootic oyster mortalities.

Altered response of oyster hemocytes to Haplosporidium nelsoni (MSX) plasmodia treated with enzymes or metabolic inhibitors

To avoid phagocytosis, parasites may mask themselves with host-like molecules that prevent recognition as nonself or they may produce substances that interfere with host cellular defenses. The protozoan parasite Haplosporidium nelsoni, which causes MSX disease in the eastern oyster Crassostrea virginica, is not ingested by host hemocytes. To assess potential avoidance mechanisms, oyster hemocytes were incubated with plasmodial stages of the parasite that had been pretreated with one of a variety of enzymes (proteases and carbohydrases) to alter surface molecules or with metabolic inhibitors to prevent the synthesis or active uptake of "masking" molecules, as well as the production and discharge of inhibitory substances. The maximum increase in phagocytosis resulting from treatment with carbohydrases was 12.5% (beta-galactosidase) and with proteases was 18% (Proteinase K). Inhibitors of aerobic metabolism resulted in a similar level of enhancement. In contrast, treatment of parasites with the glycolysis inhibitor iodoacetate enhanced phagocytosis by up to 66%. Thus, the process that obstructs phagocytosis involves aerobic and, especially, anaerobic pathways. The greater effect of a metabolic inhibitor compared to enzymes suggests that the mechanism involves more than just surface modification and may include the production of interference molecules.

Aortic dissection and use of the nicotine patch: a case involving a temporal relationship

A 33-year-old woman presented with chest and abdominal pain shortly after first and second applications of the nicotine patch. Type A aortic dissection was diagnosed and repaired. Pathological examination revealed cystic medial necrosis, subacute and acute dissection, with no evidence of chronic aortic insufficiency. The close temporal relationship between applications of the nicotine patch and onset of symptoms compatible with dissection followed by extension raises the possibility that the nicotine patch was implicated in, or precipitated, this woman's aortic dissection.

TCDD residues in fish and shellfish from U.S. waterways

TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin) in the edible portion of fish and shellfish from various U.S. waterways has been monitored since 1979. Analytical results for the period 1979-1994 are reported. Extracts obtained after column chromatographic and liquid chromatographic cleanup were examined by electron capture detection-gas chromatography (GC), and final quantitation and confirmation were performed by GC/mass spectrometry with multiple ion detection. Analyses of 1623 test samples indicated that TCDD residues in fish and shellfish were not widespread but rather were localized in areas near waste sites, chlorophenol manufacturers, and pulp and paper mills. Analytical results indicated that levels in aquatic species from these sites have been declining steadily. No TCDD (limit of detection and confirmation, 1-2 ppt) has been found in recent years in aquatic species from most Atlantic, Pacific, and Gulf of Mexico sites and Great Lakes other than Lake Ontario and Saginaw Bay (Lake Huron).

Characterization of the small subunit ribosomal RNA gene of the oyster parasite Haplosporidium costale

The small subunit ribosomal RNA (SSU rRNA) gene of the oyster parasite Haplosporidium costale was characterized from spore DNA by polymerase chain reaction (PCR) and molecular cloning. Sequence analysis showed that identical clones were obtained from separate batches of spore samples. The gene is 1791 nucleotides in size. It has 84.5% sequence similarity to that of a related oyster parasite, Haplosporidium nelsoni, 71.8% similarity to that of its oyster host, Crassostrea virginica, and 75.4% similarity to that of another oyster parasite, Perkinsus marinus. Among the variable regions of these SSU rRNA genes, H. costale-specific primers were designed and used to confirm parasite identity by the PCR technique. A common 150 base pair amplification product was obtained from DNA samples of H. costale spore DNA, DNA prepared from tissue sections of oysters infected with H. costale plasmodia, and the H. costale SSU rRNA clone. There was no detectable product from DNA samples isolated from tissue sections of oysters infected with H. nelsoni plasmodia.

Clinicopathologic correlations of antiphospholipid antibodies. An autopsy study

The clinicopathologic correlations of antiphospholipid antibodies (aPLs) have so far only been examined in case reports and highly selected series. This study assessed the incidence of aPLs in 156 consecutive, unselected autopsies and correlated the pathological findings with the clinical histories. Elevations of aPLs were found in 20.5% of the autopsy population, compared with 9.6% of age- and sex-matched controls and 2% of healthy normal subjects. There was a higher incidence of thromboembolic disease in patients with elevated aPL levels compared with those without, but the histology of thrombi was similar in both groups, with no evidence of vasculitis in the aPL-positive individuals. Patients with transient ischemic attacks and cardiac valve lesions had a high incidence of aPLs, as reported previously. Five cases that fit the designation of primary antiphospolipid antibody syndrome were noted. The study concludes that aPLs are relatively common in a hospital autopsy population and are commonly associated with thromboembolic events, that the thromboemboli are not associated with vasculitis, and that primary aPL syndrome is more common than generally appreciated.

Antibodies from patients with heparin-induced thrombocytopenia/thrombosis are specific for platelet factor 4 complexed with heparin or bound to endothelial cells

Heparin-induced thrombocytopenia/thrombosis (HITP) is thought to be mediated by immunoglobulins that activate platelets in the presence of pharmacologic concentrations of heparin, but the molecular basis for this relatively common and often serious complication of heparin therapy has not been established. We found that plasma from each of 12 patients with HITP contained high titer (> or = 1:200) antibodies that reacted with immobilized complexes of heparin and platelet factor 4 (PF4), a heparin-binding protein contained in platelet alpha-granules. Recombinant human PF4 behaved similarly to PF4 isolated from platelets in this assay system. Complexes formed at an apparent heparin/PF4 molecular ratio of approximately 1:2 (fresh heparin) and approximately 1:12 (outdated heparin) were most effective in binding antibody. Immune complexes consisting of PF4, heparin, and antibody reacted with resting platelets; this interaction was inhibited by a monoclonal antibody specific for the Fc gamma RII receptor and by excess heparin. Human umbilical vein endothelial cells, known to express heparin-like glycosaminoglycan molecules on their surface, were recognized by antibody in the presence of PF4 alone; this reaction was inhibited by excess heparin, but not by anti-Fc gamma RII. Antibodies reactive with heparin/PF4 were not found in normal plasma, but IgG and IgM antibodies were detected at dilutions of 1:10 (IgG) and 1:50 (IgM) in 3 of 50 patients (6%) with other types of immune thrombocytopenia. These findings indicate that antibodies associated with HITP react with PF4 complexed with heparin in solution or with glycosaminoglycan molecules on the surface of endothelial cells and provide the basis for a new hypothesis to explain the development of thrombocytopenia with thrombosis or disseminated intravascular coagulation in patients sensitive to heparin.

Small subunit ribosomal RNA gene sequence of the oyster parasite Perkinsus marinus

The small subunit rRNA gene of the oyster pathogen Perkinsus marinus was characterized from cells of infected oyster hemolymph by polymerase chain reaction and molecular cloning. The gene, 1,793 nucleotides in size, has 77.2% sequence similarity to that of its host, the eastern oyster Crassostrea virginica. The sequence was confirmed using recently available in vitro cultures of P. marinus. DNA from pure P. marinus culture was amplified with specific primers synthesized according to the sequence from infected oyster hemolymph, and predicted size fragments were obtained. Furthermore, restriction digests yielded fragments of expected size in amplified rDNA from in vitro cultures. The P. marinus sequence has 97.5% similarity to the Perkinsus sp. sequence from the Australian mollusc Anadara trapezia.

Cellular responses of oysters infected with Haplosporidium nelsoni: changes in circulating and tissue-infiltrating hemocytes

The protozoan parasite Haplosporidium nelsoni (MSX) elicits an inflammatory-type response in oysters, Crassostrea virginica. We assayed circulating hemocytes of oysters exposed to H. nelsoni to quantify the effects of parasitism, selection for resistance, and season on total and differential counts. All factors had a significant (P < 0.02) effect on total counts, but explained relatively little of the overall variance [season (12%) > selection (4%) > infection (2%)]. Circulating hemocyte densities increased with infection intensity in resistant animals, but were depressed in susceptible oysters with light infections. Counts in both groups were lowest in August and highest in May, at which times densities in susceptible oysters were reduced (P < 0.02) compared to those in resistant animals. No differences existed in November. Susceptible oysters may be more debilitated by infections than resistant animals, resulting in impaired circulation and depressed cell counts. The number of tissue-infiltrating hemocytes increased with infection intensity (P < 0.0001), but showed no statistically significant (P > 0.05) association with numbers of circulating hemocytes in individual oysters. Size-frequency analysis with a Coulter counter indicated that the proportion of large cells (presumed to be granular hemocytes) was lower (P < 0.0001) in susceptible oysters, which were also heavily infected, compared to resistant oysters, which had very few infections. The loss of granular hemocytes may stem from degranulation associated with tissue damage and inflammation. Present evidence suggests that the principal role of the hemocyte response in MSX disease is to plug lesions, remove debris, and repair tissues and that these functions may help oysters survive infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Results of a prospective randomized trial for treatment of severely brain-injured patients with hyperbaric oxygen

The authors enrolled 168 patients with closed-head trauma into a prospective trial to evaluate the effect of hyperbaric oxygen in the treatment of brain injury. Patients were included if they had a total Glasgow Coma Scale (GCS) score of 9 or less for at least 6 hours. After the GCS score was established and consent obtained, the patient was randomly assigned, stratified by GCS score and age, to either a treatment or a control group. Hyperbaric oxygen was administered to the treatment group in a monoplace chamber every 8 hours for 1 hour at 1.5 atm absolute; this treatment course continued for 2 weeks or until the patient was either brain dead or awake. An average of 21 treatments per patient was given. Outcome was assessed by blinded independent examiners. The entire group of 168 patients was followed for 12 months, with two patients lost to follow-up study. The mortality rate was 17% for the 84 hyperbaric oxygen-treated patients and 32% for the 82 control patients (chi-squared test, 1 df, p = 0.037). Among the 80 patients with an initial GCS score of 4, 5, or 6, the mortality rate was 17% for the hyperbaric oxygen-treated group and 42% for the controls (chi-squared test, 1 df, p = 0.04). Analysis of the 87 patients with peak intracranial pressures (ICP) greater than 20 mm Hg revealed a 21% mortality rate for the hyperbaric oxygen-treated patients, as opposed to 48% for the control group (chi-squared test, 1 df, p = 0.02). Myringotomy to reduce pain during hyperbaric oxygen treatment helped to reduce ICP. Analysis of the outcome of survivors reveals that hyperbaric oxygen treatment did not increase the number of patients in the favorable outcome categories (good recovery and moderate disability). The possibility that a different hyperbaric oxygen treatment paradigm or the addition of other agents, such as a 21-aminosteroid, may improve quality of survival is being explored.

The pathogenesis of nodular regenerative hyperplasia of the liver associated with rheumatoid vasculitis

Nodular regenerative hyperplasia (NRH) is an uncommon liver disease that typically develops in the setting of a chronic illness such as Felty's syndrome. Although the pathogenesis of NRH has not been defined, vasculitis has been postulated to play an important pathogenetic role in some cases of NRH, even though the association of NRH and vasculitis has been reported rarely. We describe two unusual cases of NRH in patients with Felty's syndrome complicated by rheumatoid vasculitis. Morphometric analysis demonstrated evidence of injury to the hepatic vasculature in the form of loss of small intrahepatic arteries and portal spaces, findings that support the hypothesis that hepatic arteritis plays a role in the development of NRH in cases associated with systemic vasculitis.

Subacute cor pulmonale due to tumor embolization

Pulmonary tumor embolism is a rare but well-documented cause of respiratory failure in patients with cancer. This entity is probably clinically underrecognized and may represent an important cause of mortality and morbidity in patients with cancer. Pulmonary tumor embolization may present at any stage of the patient's illness and indeed may be the first presentation of an occult carcinoma. In a review of 1069 nonmedicolegal autopsy protocols, we recently encountered three cases in which death had occurred from subacute cor pulmonale due to tumor embolization from breast, lung, and ovarian carcinoma. Recent advances in cytologic examination of blood samples obtained from Swan-Ganz catheters may prove useful in the diagnosis of this entity.

Genetic Variation in the Timing of Gonadal Maturation and Spawning of the Eastern Oyster, Crassostrea virginica (Gmelin)

The gonadal cycles of four groups of eastern oysters, Crassostrea virginica (Gmelin), including native stocks collected that year and inbred strains (reared in Delaware Bay for 5-6 generations) from both Long Island Sound and Delaware Bay, were compared in Delaware Bay in 1987. Inbred strains resembled their respective native stocks; both Long Island groups initiated gonadal development and spawning about one month earlier and spawned over a shorter duration than both Delaware Bay groups. Analysis of covariance revealed that the effect of time on gonadal development was statistically different (P ≤ 0.05) for all between-location group comparisons, but not for the two within-location comparisons. Thus, after six generations of inbreeding in Delaware Bay, Long Island oysters maintained their characteristic pattern of gonadal development and spawning, indicating the existence of genetically different environmental requirements for gonadal maturation between the two locations.

Evidence for regular sporulation by Haplosporidium nelsoni (MSX) (Ascetospora; Haplosporidiidae) in spat of the American oyster, Crassostrea virginica

The spore stage of Haplosporidium nelsoni, the ascetosporan parasite causing multinucleated sphere unknown (MSX) disease in oysters, Crassostrea virginica, has been reported so rarely (less than 0.01% of infected oysters) that a second host has been postulated. However, recent intensive sampling of young (less than 1 year) oysters in Delaware Bay, U.S. suggests that spore formation occurs regularly in this group and that spores are produced in at least 75-85% of all infections reaching the advanced stage. Sporulation was seasonal, occurring over two to three weeks in late June/early July and again in late summer/early fall. Our data indicate that sporulation by H. nelsoni in oysters is more common than previously suspected, occurring in a segment of the host population that may not have been sufficiently sampled in the past, and that a direct life cycle should be reconsidered.

Primary coronary artery dissection possibly related to drug hypersensitivity in a male

Primary coronary artery dissection is rare, usually affects females (greater than 85%), and has most often affected the left anterior descending coronary artery. The authors report a case that is unusual in four respects: the patient was male, the involved artery was a marginal branch of the circumflex, the resulting small infarct ruptured, and most importantly, the patient had recently experienced a drug hypersensitivity reaction. The microscopic finding of a heavy eosinophil and mast cell infiltrate around the dissected artery may indicate that dissection occurred as a result of hypersensitivity angiitis of the vasa vasorum, as has previously been suggested in the literature.

Lectin binding characteristics of haemocytes and parasites in the oyster, Crassostrea virginica, infected with Haplosporidium nelsoni (MSX)

Lectin-binding surface receptors on haemocytes from host oysters were compared with those on plasmodial stages of the ascetosporan parasite Haplosporidium nelsoni (MSX). Haemocytes were agglutinated, in descending order of strength, by WGA, HPA, LPA, ConA, and CFA. GMA, PHA, and RMA lectins failed to agglutinate at 100 micrograms/ml, the highest concentration tested. These results indicate that haemocytes contain surface receptors resembling N-acetyl-D-glucosamine and alpha-methylmannopyranoside. Fluorescent (FITC) labelled ConA and WGA also bound to H. nelsoni plasmodia, but parasites were commonly excluded from clumps of agglutinated haemocytes, except for those that were apparently trapped passively in large aggregates. Although seasonal variations existed, agglutination titres for all reacting lectins were 2- to 8-fold higher for cells from systemically infected oysters compared to control oysters not manifesting systemic infections. Preincubation of lectins in serum from control animals reduced agglutination titres 6- to 9-fold, whereas incubation in serum from systemically infected oysters reduced titres only 4- to 6-fold. The loss of lectin-like molecules from the serum of systemically infected animals, and the concurrent increase of lectin receptors in the haemocytes population, is probably related to known changes in haemocytes composition and the loss of serum glycoproteins in diseased animals. Antigenic similarities were detected between surface receptors on oyster haemocytes and those on H. nelsoni plasmodia, which may help explain the failure of oyster haemocytes to phagocytose this parasite.

A possible role for antiphospholipid antibodies in acquired cardiac valve deformity

We studied the frequency of antiphospholipid antibodies (aPL) in patients undergoing cardiac valve replacement, and present the results in the context of the pathology of the valve lesions. Forty-eight consecutive patients undergoing valve replacement were studied. Of the whole group, 15 (31%) had antibody levels greater than 2 SD above the mean for a control group of healthy persons and 11 (23%) had a level of greater than 3 SD. There was an increased frequency of elevated antibody levels in patients with valves showing fibrocalcific change and a significant association between aPL and valve thrombus. The possible role of these antibodies in the pathogenesis of the valve lesions is discussed.

Halo immobilization and surgical fusion: relative indications and effectiveness in the treatment of 140 cervical spine injuries

In the management of cervical spine injuries, it is not always clear when to use halo immobilization alone, surgical fusion alone, or a combination of the two. To investigate the relative effectiveness of each of these approaches, we reviewed the medical records of 140 patients with cervical spine injuries treated with either halo immobilization or surgical fusion, or both. Seventy (50%) of the patients were neurologically intact on admission (two of these were paraplegic from previous injuries). Halo immobilization was used as the primary treatment in 99 patients, and yielded a successful fusion rate of 78%. Within this group, the 26 patients with hyperflexion-anterior subluxation injuries had only a 54% successful fusion rate, while the rate for the 73 with non-flexion injuries was 87% (Chi-square = 11.36; p = 0.0008). Surgical fusion was used as the primary treatment in 41 patients and as a subsequent treatment in the 22 for whom halo immobilization did not bring about fusion. Of these 63 patients treated with surgical fusion, six remained unstable after the surgery; five of these six had sustained a hyperflexion-anterior subluxation. One patient experienced neurologic deterioration after surgical fusion. There were three deaths in the entire series. Excluding fusion failure, complications with halo immobilization were frequent (25%) but usually minor; with surgical fusion, less frequent (6%) but usually more severe. We draw the following conclusions. 1) Halo immobilization brings about satisfactory healing for most fracture types. 2) Both halo immobilization and surgical fusion have relatively high failure rates in the treatment of hyperflexion-anterior subluxation injury, with or without bilaterally locked facets.(ABSTRACT TRUNCATED AT 250 WORDS)

Premature stroke in a family with lupus anticoagulant and antiphospholipid antibodies

Lupus anticoagulant and antiphospholipid antibodies are associated with thromboembolic phenomena in individuals both with and without systemic lupus erythematosus. A 32-year-old woman (the index case) with lupus anticoagulant, multiple cerebrovascular events, and a family history of premature stroke raised the possibility of a familial diathesis. Histories or interviews, examinations, and blood tests were obtained for 23 members of four generations of her family. Four individuals had suffered strokes and three more had suffered neurologic symptoms. Two living individuals who had suffered strokes, two individuals with neurologic symptoms, and five asymptomatic individuals had antiphospholipid activity in their blood. In addition, a cousin of the index case was found to have systemic lupus erythematosus and antiphospholipid activity. Elevated concentrations of von Willebrand factor antigen were found associated with some positive lupus anticoagulant assays, the highest concentrations in the two individuals with stroke. The characteristic presentation of the index case and her good response to treatment suggests that further studies of families in whom antiphospholipid antibodies may represent a risk factor for stroke is worthwhile.

The association of pulmonary hypertension with rheumatoid arthritis

Pulmonary hypertension due to vasculitis is a rare complication of rheumatoid arthritis (RA). We describe 2 patients with RA and pulmonary hypertension who died with a clinical diagnosis of idiopathic pulmonary hypertension. In each case postmortem examination revealed severe pulmonary vasculitis as the actual cause of the hypertension. Subclinical systemic vasculitis was found in one case and hepatic nodular regenerative hyperplasia in both cases. Pulmonary vasculitis must be included in the differential diagnosis of pulmonary hypertension associated with RA. Open lung biopsy should be considered in this clinical setting in an attempt to identify this potentially treatable cause of pulmonary hypertension.

Thrombotic endocarditis and lupus anticoagulant. A pathogenetic possibility for idiopathic 'rheumatic type' valvular heart disease

Lupus anticoagulant and anti-phospholipid antibodies are well recognized as being associated with thromboembolic disorders in patients both with and without systemic lupus erythematosus (SLE). There have been recent reports of the association of lupus anticoagulant and antiphospholipid antibodies with severe valvular heart disease in patients with SLE and it has been suggested that organizing thrombus on the surface of the valve may be a cause of distortion and subsequent dysfunction. We describe two patients who did not have SLE, but who did have both lupus anticoagulant and antiphospholipid antibodies. Both had severe valvular heart disease, the pathology of which demonstrates valve distortion by layers of organizing thrombus identical to that of previously described patients with SLE. The gross appearance of these valves is similar to that of the valves in "rheumatic" heart disease. We suggest that in some patients with "rheumatic" heart disease, but without a history of rheumatic fever, the prothrombotic tendency associated with lupus anticoagulant and phospholipid antibodies may either contribute to, or be responsible for, the pathogenesis of "rheumatic" type valve deformities.

A clinical comparison of subarachnoid catheters to ventriculostomy and subarachnoid bolts: a prospective study

A subarachnoid catheter (SAC) technique of continuous intracranial pressure (ICP) monitoring is presented and compared to intraventricular catheters (IVC's) and subarachnoid bolts (SAB's) in 40 neurosurgical patients. Thirty-one patients were monitored simultaneously with SAC's and IVC's and nine patients with SAC's and SAB's, and the ICP waveforms and measurements were compared. The duration of monitoring ranged from 15 hours to 11 days, and the initial ICP from 2 to 117 torr. A total of 42 SAC's were placed; two that entered brain parenchyma were redirected. One SAC placement was associated with an intracerebral hematoma. There were no infections. For the 31 patients with SAC's and IVC's, there were 2706 pairs of ICP measurements with a mean difference of -0.12 torr and a standard deviation of 5.29 torr. The waveforms from the SAC's and IVC's were indistinguishable. For the nine patients with SAC's and SAB's, there were 773 pairs of ICP measurements with a mean difference of 1.24 torr and a standard deviation of 32.83 torr. The SAB waveforms were of varying quality and all dampened with time. The paired t-test (ts) demonstrated no statistically significant difference between SAC's and IVC's (ts = - 1.19). An analysis of variance demonstrated the scatter of the measurements obtained from SAB's to be 38.5 times that of SAC's, p less than 0.00005. The SAB is shown to be relatively inaccurate with a wide range of variance, while the SAC is demonstrated to be an accurate, reliable, and safe method of continuous ICP measurement and an acceptable alternative to ventriculostomy.

Association of lupus anticoagulant with severe valvular heart disease in systemic lupus erythematosus

Two cases of systemic lupus erythematosus with hemodynamically significant mitral valve dysfunction and associated lupus anticoagulant are reported. Both patients underwent valve replacement and both had thrombus formation on the mitral valve, one pre- and the other postoperatively. Both patients suffered a number of extracardiac thromboses at different times in the course of their illness. The contribution of the lupus anticoagulant to the thrombotic problems, and its possible relationship to the pathogenesis of Libman-Sacks endocarditis are discussed.

Infection and mortality patterns in strains of oysters Crassostrea virginica selected for resistance to the parasite Haplosporidium nelsoni (MSX)

Strains of oysters Crassostrea virginica resistant to mortality caused by the parasite Haplosporidium nelsoni (MSX) were developed and tested through 6 generations. In addition, strains in each generation were followed for up to 6 yr of continuous exposure to the parasite in nature. Selected strains responded to challenge by the parasite with gradually improved survival in successive generations. They were slower to develop patent infections than were unselected groups and were able to delay mortality after infections did develop, but under repeated exposure most oysters eventually died with H. nelsoni parasitism. Many selected strains, however, reached market size before significant mortalities occurred. The data suggest that resistance to H. nelsoni mortality is under the influence of many genes. No clear defense mechanism has been described and we hypothesize that resistance to H. nelsoni may, in part, involve a physiological state in which selected oysters temporarily fail to provide a suitable habitat for the parasite. Temporary insusceptibility would, in this view, be followed by an increased ability to tolerate the parasite when conditions for its development are present. Selection would then favor individuals that are able to prolong periods of insusceptibility and/or to carry out basic life processes while parasitized.

Distribution of amiodarone and its metabolite, desethylamiodarone, in human tissues

The distribution of the antiarrhythmic drug amiodarone and its principal lipophilic metabolite, desethylamiodarone, was determined in postmortem tissues of six patients who received amiodarone therapy (treatment period, 6-189 days; total dose, 4.8-127.0 g). Amiodarone concentration was highest in liver, lung, adipose tissue, and pancreas, followed by kidney, heart (left ventricle), and thyroid gland, and lowest in antemortem plasma. There was no measurable amiodarone in brain (less than 1.0 microgram/g). Desethylamiodarone concentration was highest in liver and lung, followed by pancreas, adipose tissue, kidney, heart, thyroid gland, and brain, and lowest in plasma. For most patients, the desethylamiodarone concentration was higher than the amiodarone concentration in liver, lung, kidney, heart, thyroid gland, and brain, whereas the parent drug concentration was higher than the metabolite concentration in adipose tissue, pancreas, and plasma. Tissue amiodarone and desethylamiodarone concentrations appeared to be related more closely to the total dose of amiodarone than to their respective plasma concentrations. One patient died of apparent amiodarone-induced pulmonary toxicity after an 18-day period of pharmacotherapy. Clinical evidence of pulmonary dysfunction appeared at 15 days after the initiation of amiodarone therapy, and the patient died at 23 days. Histologic assessment of a lung necropsy specimen revealed acute alveolar interstitial damage. This case represents the earliest reported incident of amiodarone-induced pulmonary toxicity.

Rapid ventricular pacing in the dog: pathophysiologic studies of heart failure

We examined rapid ventricular cardiac pacing as a means of inducing heart failure in the dog to establish the sequence and nature of physiologic compensation in this preparation. Seven animals paced at 250 beats/min for 3 weeks (VP1 group) showed an increase in cardiac size from 78.5 +/- 9.5(SD) to 105.8 +/- 13.0 cm2, a reduction in mean arterial pressure from 149 +/- 7 to 130 +/- 21 mm Hg, a fall in cardiac index from 196 +/- 57 to 125 +/- 37 ml/kg/min, and an increase in left ventricular filling pressure from 6 +/- 5 to 22 +/- 9 mm Hg and in right atrial pressure from 2 +/- 2 to 5 +/- 3 mm Hg. An additional series of six animals (VP2 group) was paced until a clear biologic end point for heart failure was reached (average 5.3 +/- 1.9 weeks) and they showed similar but more advanced changes compared with the VP1 group. The changes in cardiac size and hemodynamics in the VP1 and VP2 groups were significantly different from those in parallel studies of 10 sham-operated animals. Plasma norepinephrine and renin activity were unchanged in sham-operated animals, whereas in the VP1 group, plasma norepinephrine rose from 338 +/- 118 to 764 +/- 567 pg/ml (p less than .05), but plasma renin activity did not change. In the VP2 group norepinephrine rose from 471 +/- 285 to 999 +/- 425 pg/ml (p less than .025) and plasma renin rose from 2.1 +/- 1.5 to 8.0 +/- 7.1 ng/ml/hr (p less than .05). There was an excellent correlation between plasma norepinephrine and renin activity before the animals were killed in both the VP1 and VP2 groups (r = .88, p less than .001). No change was evident in atrial natriuretic factor content, as determined by bioassay, in sham-operated or VP1 group animals. However, there was a significant reduction in atrial natriuretic activity from the right atrium that was inversely correlated with the level of right atrial pressure in the VP2 group.

Mitral regurgitation due to lupus endocarditis treated with valve replacement

A murmur of mitral regurgitation developed in a 20-year-old woman with a 2-year history of systemic lupus erythematosus. Echocardiography revealed thickening of both valve leaflets and abnormal diastolic motion of the posterior one, confirming the diagnosis of mitral endocarditis. The mitral regurgitation progressed to cause congestive heart failure, which was refractory to drug therapy but was effectively treated with mitral valve replacement.

Indwelling cardiac catheters. An autopsy study of associated endocardial lesions

An autopsy study was carried out to assess the relationship between indwelling intracardiac catheters and hemorrhagic, thrombotic, and infective lesions of the right heart endocardium and valve. Intracardiac catheters cause such lesions frequently, with a spectrum from uncomplicated valvular hemorrhage through nonbacterial thrombotic endocarditis to infective endocarditis. Pulmonary emboli were associated with the thrombotic, infective lesions. Endocardial lesions are more commonly seen with Swan-Ganz (SG) catheters; with these, lesions are more common and severe, with longer periods of catheterization. Pulmonic-valve lesions were only seen with SG catheters. However, not all hemorrhagic lesions in the right heart endocardium were associated with catheters, because a few inpatients without catheters had small subendocardial valvular hemorrhages; the cause of these hemorrhages is obscure because they were not seen in the hearts of patients who died outside the hospital.

Evaluation of antigen-induced buffy coat leucocyte aggregation as a simple test of allergic reactivity

The phenomenon of antigen-induced aggregation of human buffy coat leucocytes correlates well with skin testing using purified protein derivative of tuberculin as the antigen and in this system appears to be a simple, sensitive test of cell-mediated immunity. The same phenomenon may, however, be used as an indicator of humoral immunity. In addition antigen-induced buffy coat leucocyte aggregation is suppressed by serum from patients with Hodgkin's disease and sarcoidosis. The possible uses and also the limitations of this test are discussed.