Adaptation of Striped Bass to Sea Water Following Direct Transfer from Freshwater: Morphological, Biochemical, and Physiological Parameters

There has been heightened interest in the biology of striped bass (Morone saxatilis) because of increased pollution in their native spawning grounds and because of their extensive use in landlocked sport fisheries. Their euryhalinity makes them an excellent species for osmoregulation studies. The objective of this research was to study the rate of adaptation of striped bass gills to sea water (3% salt) after direct transfer from freshwater using biochemical (ion transport enzyme levels), physiological (chloride efflux), and ultrastructural methods. Striped bass have specialized osmoregulatory cells located on the interlamellar and afferent surfaces of their gill filaments as shown by light microscopy (LM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). SEM studies show that apical pit (opening of one or more chloride cells) morphology changes during sea water adaptation, and the number of apical pits increases by 32.5% after two weeks in sea water. Chloride cell size and number, extent of basolateral tubular system, and number of mitochondria per chloride cell appear to increase upon adaptation to sea water. Sodium-potassium adenosine triphosphatase (Na,K-ATPase) activity is maximal on day 3 after transfer to sea water. Studies suggest that cortisol may act as a hormonal mediator for long term adaptation to sea water. The general morphology of both freshwater and sea water adapted fish gills were studied. Preliminary studies indicate that the osmium-dimethylsulfoxide-osmium method can be used to investigate intracellular structural changes in striped bass gills. Since the chloride cells are associated with the afferent surface of the filament, the blood supply to that area is also of great interest in osmoregulation studies. Studies of the gill vasculature using corrosion casting (i.e. filling blood vessels with plastic resins) and SEM indicate that the blood vessel distribution in the striped bass gill is similar to that of other euryhaline species with arterio-arterial, arterio-venous, and nutritive pathways. Blood flow may be controlled at a variety of places by sphincters, shunts and cellular contraction. Correlation of these biochemical, physiological and anatomical measurements will aid in the understanding of the process of adaptation to sea water. (Abstract shortened with permission of author.

The Gill Arch of the Striped Bass, Morone Saxatilis. II. Microvasculature Studied with Vascular Corrosion Casting and Scanning Electron Microscopy

The gill vasculature of euryhaline striped bass, Morone saxatilis, was examined by scanning electron microscopy of corrosion casts prepared by injecting resin (either Mercox/Sevriton or L.R. White) into the ventral aorta. The vasculature of the striped bass gill appears to be similar to that of other euryhaline species. The striped bass gill has three major vascular systems: (1) a respiratory system, (2) an arterio-venous system, and (3) a nutritive system. In the respiratory system, blood from the afferent branchial artery flows to each filament via an afferent filamental artery, and from there to the highly vascularized respiratory lamellae. Lamellar blood is conducted back to the efferent branchial artery via the efferent filamental artery. In the second system arterio-venous anastomoses transport blood from the efferent filamental artery to the central venous sinus. Blood then flows to the branchial vein either directly or via paired afferent companion vessels. No arterio-venous anastomoses connecting the prelamellar vessels with the central venous sinus have been found. Finally, nutritive branches to the arch are provided by the efferent branchial artery and the efferent filamental artery. The striped bass does not have a lamellar bypass system involving the central venous sinus as reported in other species. Intralamellar distribution mechanisms and lamellar recruitment may account for changes in respiratory lamellar perfusion during decreased and increased oxygen demand, respectively. The central venous sinus\u27 role may be partially nutritional since its blood is oxygenated. However, its complex vascular connections may permit a variety of other functions

A ternary mechanism for NADH oxidation by positively charged electron acceptors, catalyzed at the flavin site in respiratory complex I

AbstractThe flavin mononucleotide in complex I (NADH:ubiquinone oxidoreductase) catalyzes NADH oxidation, O2 reduction to superoxide, and the reduction of several ‘artificial’ electron acceptors. Here, we show that the positively-charged electron acceptors paraquat and hexaammineruthenium(III) react with the nucleotide-bound reduced flavin in complex I, by an unusual ternary mechanism. NADH, ATP, ADP and ADP-ribose stimulate the reactions, indicating that the positively-charged acceptors interact with their negatively-charged phosphates. Our mechanism for paraquat reduction defines a new mechanism for superoxide production by complex I (by redox cycling); in contrast to direct O2 reduction the rate is stimulated, not inhibited, by high NADH concentrations

A perpetual switching system in pulmonary capillaries

Of the 300 billion capillaries in the human lung, a small fraction meet normal oxygen requirements at rest, with the remainder forming a large reserve. The maximum oxygen demands of the acute stress response require that the reserve capillaries are rapidly recruited. To remain primed for emergencies, the normal cardiac output must be parceled throughout the capillary bed to maintain low opening pressures. The flow-distributing system requires complex switching. Because the pulmonary microcirculation contains contractile machinery, one hypothesis posits an active switching system. The opposing hypothesis is based on passive switching that requires no regulation. Both hypotheses were tested ex vivo in canine lung lobes. The lobes were perfused first with autologous blood, and capillary switching patterns were recorded by videomicroscopy. Next, the vasculature of the lobes was saline flushed, fixed by glutaraldehyde perfusion, flushed again, and then reperfused with the original, unfixed blood. Flow patterns through the same capillaries were recorded again. The 16-min-long videos were divided into 4-s increments. Each capillary segment was recorded as being perfused if at least one red blood cell crossed the entire segment. Otherwise it was recorded as unperfused. These binary measurements were made manually for each segment during every 4 s throughout the 16-min recordings of the fresh and fixed capillaries (>60,000 measurements). Unexpectedly, the switching patterns did not change after fixation. We conclude that the pulmonary capillaries can remain primed for emergencies without requiring regulation: no detectors, no feedback loops, and no effectors-a rare system in biology. NEW & NOTEWORTHY The fluctuating flow patterns of red blood cells within the pulmonary capillary networks have been assumed to be actively controlled within the pulmonary microcirculation. Here we show that the capillary flow switching patterns in the same network are the same whether the lungs are fresh or fixed. This unexpected observation can be successfully explained by a new model of pulmonary capillary flow based on chaos theory and fractal mathematics

Confocal laser scanning microscopy and three-dimensional reconstruction of cell clusters in serous fluids

Thick cell clusters are a common finding in reactive and malignant effusions. In order to arrive at a diagnosis, clusters are evaluated for certain cytomorphologic features including size, shape, smooth vs. scalloped borders, and three-dimensional (3-D) configuration. By conventional microscopy, the image of these clusters is often blurred due to limitations in resolution. Consequently, the exact internal structure and cellular arrangement within these clusters cannot be adequately determined. Utilizing confocal laser scanning microscopy (CLSM), we examined serous fluids from a variety of conditions. Cases included mesothelioma, adenocarcinoma, and papillary adenocarcinoma. Smears were stained with 0.01% ethidium bromide and 1% eosin Y, followed by analysis with an ACAS 570™ image analyzer (Meridian Instruments, Inc. Okemos, MI). Serial confocal fluorescence images were acquired, which allowed 3-D reconstruction of the clusters. Mesothelioma clusters (excluding those with obvious central collagen cores by light microscopy) appeared to be formed of the following configurations: 1) randomly coiled cords of cells, 2) small papillae encompassing central cores, and 3) tissue fragments with pseudoacinar formation. In contrast, adenocarcinomas had a more orderly pattern, with tightly cohesive cells and true acinar formation. Diagn. Cytopathol. 1997;17: 272–279. © 1997 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/35303/1/7_ftp.pd

Indinavir and nelfinavir inhibit proximal insulin receptor signaling and salicylate abrogates inhibition : potential role of the NFkappa B pathway

The molecular basis of insulin resistance induced by HIV protease inhibitors (HPIs) remains unclear. In this study, Chinese hamster ovary cells transfected with high levels of human insulin receptor (CHO-IR) and 3T3-L1 adipocytes were used to elucidate the mechanism of this side effect. Indinavir and nelfinavir induced a significant decrease in tyrosine phosphorylation of the insulin receptor b-subunit. Indinavir caused a significant increase in the phosphorylation of insulin receptor substrate-1 (IRS-1) on serine 307 (S307) in both CHO-IR cells and 3T3-L1 adipocytes. Nelfinavir also inhibited phosphorylation of Map/ERK kinase without affecting insulin-stimulated Akt phosphorylation. Concomitantly, levels of protein tyrosine phosphatase 1B (PTP1B), suppressor of cytokines signaling-1 and -3 (SOCS-1 and -3), Src homology 2B (SH2B) and adapter protein with a pleckstrin homology domain and an SH2 domain (APS) were not altered significantly. When CHO-IR cells were pre-treated with sodium salicylate (NaSal), the effects of indinavir on tyrosine phosphorylation of the IR b-subunit and phosphorylation of IRS-1 at S307 were abrogated. These data suggest a potential role for the NFkB pathway in insulin resistance induced by HPIs.National Research Foundation (Rated Researcher Incentive funding) of South Africa, the National Health Laboratory Service, South Africa and the Young Lecturer Scheme under Universiti Teknologi MARA and Ministry of Higher Education of Malaysia.http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1097-4644hb201

A multicenter comparison between Child Pugh and ALBI scores in patients treated with sorafenib for hepatocellular carcinoma

Background & aims: The ALBI grade was proposed as an objective means to evaluate liver function in patients with Hepatocellular Carcinoma (HCC). ALBI grade 1 vs 2 were proposed as stratification factors within the Child Pugh (CP) A class. However, the original publication did not provide comparison with the sub-classification by points (5 to 15) within the CP classification. Methods: We retrospectively analyzed data from patients treated with sorafenib for HCC from 17 centers in United Kingdom and France. Overall survival (OS) was analyzed with the Kaplan-Meier method and a Cox regression model. Discriminatory abilities of the classifications were assessed with the log likelihood ratio, Harrell’s C statistics and Akaike information criterion. Results: Data from 1,019 patients were collected, of which 905 could be assessed for both scores. 92% of ALBI grade 1 were CP A5 while ALBI 2 included a broad range of CP scores of which 44% were CP A6. Median OS was 10.2, 7.0 and 3.6 months for CP scores A5, A6 and >A6, respectively (P<0.001), Hazard Ratio (HR)=1.60 (95%CI: 1.35-1.89, P<0.001) for A6 vs A5. Median OS was 10.9, 6.6 and 3.0 months for ALBI grade 1, 2 and 3, respectively (P<0.001), HR=1.68 (1.43-1.97, P<0.001) for grade 2 vs 1. Discriminatory abilities of CP and ALBI were similar in the CP A population, but better for CP in the overall population. Conclusions: Our findings support the use CP class A as an inclusion criterion, and ALBI as a stratification factor in trials of systemic therapy

High molecular weight (HMW) : total adiponectin ratio is low in HIV-infected women receiving protease inhibitors

BACKGROUND : At the time of the study, the HIV-treatment policy in South Africa included highly active antiretroviral therapy (HAART) regimens 1 (nucleotide reverse transcriptase inhibitors (NRTIs) only), and 2 (protease inhibitors (PI) and NRTIs). HAART is associated with the lipodystrophy syndrome, insulin resistance and reduced total adiponectin (TA) levels. The high molecular weight (HMW):TA ratio is a superior marker of insulin resistance. The aim of this study was to establish whether HMW:TA ratios are low in patients on PIs and whether they correlate with insulin resistance. METHODS : This was a cross-sectional study undertaken in an antiretroviral clinic at a tertiary hospital. The participants were 66 HIV-infected females: 22 were on regimen 2 (PI group), 22 on regimen 1 (non-PI) and 22 treatment naïve (TN), matched for BMI and age. Patients with a history of diabetes or impaired glucose tolerance were excluded. Serum adiponectin multimers were analysed using the AlpcoTM Adiponectin (Multimeric) enzyme immunoassay. Waist hip ratios (WHR), glucose and insulin levels were assessed, and HOMA-IR and QUICKI calculated. Data were analysed non-parametrically and multivariate analysis was performed. RESULTS : TA and HMW levels were lower in the treatment groups than in the TN group. HMW:TA was lower in the PI than in the non-PI and TN groups, and in the non-PI than in the TN groups. HMW:TA correlated negatively with waist, insulin and HOMA-IR, independently of BMI and duration of therapy. HOMA-IR and QUICKI did not differ among the groups. CONCLUSION : HMW :TA is significantly decreased with HAART (particularly with PIs, but also with non-PIs) and may be a more sensitive marker of insulin resistance in these patients than conventional markers or HMW and total adiponectin individually.National Health Laboratory Service Research Trust Fund, the National Research Foundation, the World Diabetes Foundation and the Department of Health.http://www.biomedcentral.com/bmcclinpathol/hb201

Expression of the cell to cell adhesion molecule, ALCAM, in breast cancer patients and the potential link with skeletal metastasis

The activated leukocyte cell adhesion molecule (ALCAM) is involved in cell migration and adhesion. Decreased levels of ALCAM expression in breast cancer tissue are known to correlate with poor prognosis. The current study specifically investigated the ALCAM expression in tumours which developed skeletal metastasis. Fresh frozen primary breast cancer tissues (n=234) and non-neoplastic mammary tissue (n=34) were used. The distribution and location of ALCAM was assessed using immunohistochemical methods and the level of ALCAM was determined using quantitative RT-PCR. The results were analysed against the clinical and pathological data. ALCAM staining was largely membranous and cytoplasmic in normal epithelial cells and is significantly stronger than in cancer cells (p=0.023) and patients who develop skeletal metastasis (p=0.048). The ALCAM transcript levels were lowest in patients with skeletal metastasis (p=0.0048) but were also significantly lower in patients who developed local recurrence (p=0.040) and in those who died from breast cancer (p=0.0075). Patients with moderate and poor prognostic indices have a lower level than those with a good index (p=0.05 and p=0.0089 respectively) and ER-positive tumours show a lower level than ER-negative (p=0.043). Ductal carcinomas, 86% of the cohort, have a similar pattern of changes with skeletal metastasis patients having significantly lower levels (p=0.015). This study has, for the first time, shown that patients who develop skeletal metastasis tend to have the lowest levels of ALCAM transcripts in their breast cancers, a finding potentially useful for clinical practic