A case‐based review of a simplified quantitative approach to acid‐base analysis

Objective – To present a simplified quantitative approach to acid‐base analysis and to demonstrate its clinical utility. Data Sources – Original research articles and textbooks. Data Synthesis – A simplified quantitative approach to acid‐base analysis is presented, which is derived from the Fencl‐Stewart approach and calculates the magnitude of the effect on the standardized base excess (SBE) of 5 separate variables: (1) a free water effect (marked by sodium concentration), (2) an effect marked by the chloride concentration, (3) an albumin effect, (4) a lactate effect, and (5) a phosphate effect. Six clinical cases with acid‐base abnormalities are presented in which the quantitative approach provides information that is not apparent from the traditional approach. Conclusion – This simplified quantitative approach provides a comprehensive evaluation of complex acid‐base disorders, identifies individual processes and their relative influence on SBE, and aids in the development of an appropriate therapeutic plan.     

Chlorophyll <Emphasis Type="Italic">a</Emphasis> fluorescence,under half of the adaptive growth-irradiance,for high-throughput sensing of leaf-water deficit in <Emphasis Type="Italic">Arabidopsis thaliana</Emphasis> accessions

Background

Non-invasive and high-throughput monitoring of drought in plants from its initiation to visible symptoms is essential to quest drought tolerant varieties. Among the existing methods, chlorophyll a fluorescence (ChlF) imaging has the potential to probe systematic changes in photosynthetic reactions; however, prerequisite of dark-adaptation limits its use for high-throughput screening.

Results

To improve the throughput monitoring of plants, we have exploited their light-adaptive strategy, and investigated possibilities of measuring ChlF transients under low ambient irradiance. We found that the ChlF transients and associated parameters of two contrasting Arabidopsis thaliana accessions, Rsch and Co, give almost similar information, when measured either after ~20 min dark-adaptation or in the presence of half of the adaptive growth-irradiance. The fluorescence parameters, effective quantum yield of PSII photochemistry (Φ_PSII) and fluorescence decrease ratio (R _FD) resulting from this approach enabled us to differentiate accessions that is often not possible by well-established dark-adapted fluorescence parameter maximum quantum efficiency of PSII photochemistry (F _V/F _M). Further, we screened ChlF transients in rosettes of well-watered and drought-stressed six A. thaliana accessions, under half of the adaptive growth-irradiance, without any prior dark-adaptation. Relative water content (RWC) in leaves was also assayed and compared to the ChlF parameters. As expected, the RWC was significantly different in drought-stressed from that in well-watered plants in all the six investigated accessions on day-10 of induced drought; the maximum reduction in the RWC was obtained for Rsch (16%), whereas the minimum reduction was for Co (~7%). Drought induced changes were reflected in several features of ChlF transients; combinatorial images obtained from pattern recognition algorithms, trained on pixels of image sequence, improved the contrast among drought-stressed accessions, and the derived images were well-correlated with their RWC.

Conclusions

We demonstrate here that ChlF transients and associated parameters measured even in the presence of low ambient irradiance preserved its features comparable to that of measured after dark-adaptation and discriminated the accessions having differential geographical origin; further, in combination with combinatorial image analysis tools, these data may be readily employed for early sensing and mapping effects of drought on plant’s physiology via easy and fully non-invasive means.

     

Repeat laparotomy for the treatment of septic peritonitis in a Bornean orangutan (Pongo pygmaeus pygmaeus)

A 9-yr-old female Bornean orangutan (Pongo pygmaeus pygmaeus) presented with a 48-hr history of depression, lethargy, anorexia, and mucoid discharge from the rectum. Clinical, radiographic, and ultrasonographic examination demonstrated the presence of multiple distended loops of intestine, intestinal adhesions, and free gas within the abdomen. During exploratory laparotomy, fibrinopurulent diffuse peritonitis as a result of a ruptured intrapelvic abscess with associated large bowel adhesions was evident. The abdomen was thoroughly lavaged, necrotic debris and abscess wall removed, and fibrinous adhesions disrupted. The orangutan was kept sedated for 48 hr to allow for intensive care. Six months later, when the orangutan presented with similar clinical signs, ultrasonographic examination demonstrated the presence of a pelvic abscess. The previous procedure was repeated with the addition of a hysterectomy. This report is the first documentation of long-term management following surgical intervention for internal abdominal abscessation and septic peritonitis in a great ape.     

Precondition for Integration: In Support of Stand-alone Social Science in Rangeland and Silvopastoral Research

Most agree that social and ecological approaches should be integrated to ensure sustainable management of natural resources. However, an analysis of the content of three problem-based journals shows that if social sciences are included at all, they are typically subservient to natural sciences, and that quantitative approaches are privileged. We argue that true integration is achievable only if natural sciences and social sciences are each robust and if they meet eye to eye. We call for more openness to stand-alone social science research in problem-based journals, especially to research using qualitative methods. We highlight the potential insights derived from studying decision makers at the microlevel: the pastoralists, farmers, ranchers, and foresters who make final management choices. We argue that publishing such qualitative social sciences promotes dialogue across disciplines, strengthens integration, and increases the real-world impact of research.     

Pharmacokinetics of fluconazole in loggerhead sea turtles (Caretta caretta) after single intravenous and subcutaneous injections, and multiple subcutaneous injections.

Superficial and systemic mycotic infections are common among clinically ill sea turtles, which places growing importance on the establishment of pharmacokinetic-based dosage regimens for antifungal drugs. The pharmacokinetic properties of the antifungal drug fluconazole, after intravenous (i.v.) and subcutaneous (s.c.) injections, were studied in juvenile loggerhead sea turtles (Caretta caretta) housed at 23.0-26.5 degrees C. Fluconazole pharmacokinetic properties were further assessed in a multiple-dose s.c. regimen derived from the pharmacokinetic parameters determined in the single-dose study. Pharmacokinetic parameters were calculated, using a two-compartment model, from plasma concentration-time data obtained after single i.v. and s.c. administrations of fluconazole at a dosage of 2.5 mg/ kg body weight in six juvenile sea turtles. Blood samples were collected at intervals through 120 hr after each dose, and the concentration of fluconazole in plasma was measured by reverse-phase high-performance liquid chromatography. The i.v. and s.c. elimination half-lives were 139.5 +/- 36.0 and 132.6 +/- 48.7 hr (mean +/- SD), respectively. Systemic clearance of fluconazole was 8.2 +/- 4.3 ml/kg x hr, and the apparent volume of distribution at steady state was 1.38 +/- 0.29 L/kg. A multiple-dose regimen was derived, which consisted of a loading dose of 21 mg/kg body weight and subsequent doses of 10 mg/kg administered through s.c. injection every 120 hr (5 days). This regimen was administered to four juvenile sea turtles for 10 days, and blood samples were taken to determine peak and trough plasma concentrations of fluconazole. The mean concentrations for the two peak concentrations were 16.9 +/- 1.1 and 19.1 +/- 2.8 microg/ml 4 hr after dosing, and the mean concentrations for the three trough concentrations were 7.2 +/- 2.2, 10.4 +/- 2.7, and 10.7 +/- 2.9 microg/ml 120 hr after dosing. The terminal half-life after the last dose was calculated at 143 hr. Throughout the multiple dosing, fluconazole concentrations remained above approximately 8 microg/ml, a concentration targeted when treating mycotic infections in humans. The results of this study suggest that fluconazole can be effectively administered to sea turtles at a dosage of 10 mg/kg every 5 days after a loading dose of 21 mg/kg.     

How fisher‐influenced marine closed areas contribute to ecosystem‐based management: A review and performance indicator scorecard

A rapid review of the literature on closed areas that recognize key ecosystem‐based management (EBM) principles of fisheries and biodiversity conservation and had fisher involvement was employed to review closed areas worldwide from a fisheries perspective and to develop a scorecard that can assess their efficacy. The review provided 523 abstracts of which 19 areas from various regions worldwide had peer‐reviewed studies that met strict selection criteria. Criteria included fisher involvement, biodiversity conservation and fisheries management objectives. A repeat search without “fisher” and synonyms found, 62,622 papers indicating that most closed area studies had no mention of any fisher involvement. The general success of the areas selected suggests that fisher involvement benefits both biological conservation and fisheries management. Fisheries and biodiversity conservation outcomes were not exclusive to any one type of management closure (e.g. MPA, Fishery Closure). Twenty‐four indicators were selected, designed to provide measurable targets. High scoring indicators included management, planning and socio‐economic indicators such as local support (100%), habitat protection (100%), conservation and fisheries objectives (100%), monitoring (91.7%) and fishers concerns (91.7%). Bio‐ecological‐based indicators scored lower in most cases for all types of areas. Fisheries closures rated as highly as the MPAs with respect to both fisheries and bio‐ecological indicators. The scorecard provided a reasonable means to evaluate management success in the light of often qualitative or missing data. Addressing the interests and utilizing knowledge of those affected by closures and familiar with the area, most often local fishers, is key to achieving management objectives.     

Herbicidal action of 2-hydroxy-3-alkyl-1,4-naphthoquinones

The main mode of herbicidal activity of 2-hydroxy-3-alkyl-1,4-naphthoquinones is shown to be inhibition of photosystem II (PSII). The herbicidal and in vitro activities have been measured and correlated with their (Log)octanol/water partition coefficients (Log Ko/w). The length of the 3-n-alkyl substituent for optimal activity differed between herbicidal and in vitro activity. The maximum in vitro activity was given by the nonyl to dodecyl homologues (Log Ko/w between 6.54 and 8.12), whereas herbicidal activity peaked with the n-hexyl compound (Log Ko/w = 4.95). The effect of chain branching was also investigated using isomeric pentyl analogues substituted at position 3. All exhibited similar levels of in vitro activities but herbicidal activities differed, albeit moderately, with the exception of one analogue that was much less phytotoxic. Other modes of action were also investigated using two representative compounds. They did not show any activity on photosystem I or mitochondrial complex I, or generate toxic oxygen radicals by redox cycling reactions. Only moderate activity was found against mitochondrial complex III from plants, in contrast to much higher corresponding activity using an insect enzyme.