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PubMed2003

Is inhibin B a potential marker of gonadotoxicity in prepubertal children treated for cancer?

BACKGROUND AND OBJECTIVE: Chemotherapy treatment of childhood cancer may impair gonadal function, which may be manifested only in adulthood as permanent sterility. Detection of gonadal dysfunction in prepubertal children has been hampered by the absence of a sensitive marker. Inhibin B is secreted by small antral follicles and Sertoli cells in females and males, respectively, and may be a marker of gonadal function in prepubertal children. The aim of this pilot study was to evaluate inhibin B in relation to sensitive measurements of gonadotrophins as markers of the early gonadotoxic effects of chemotherapy in prepubertal children treated for cancer. STUDY DESIGN AND SUBJECTS: Twenty-five prepubertal children (9 females), median age 4.5 years (range 1.2-12.8 years) with cancer (16 solid tumours, nine acute lymphoblastic leukaemia, ALL) were studied longitudinally. Blood samples were collected before and during chemotherapy (solid tumours) or immediately following induction and first intensification (ALL). Post-treatment (1-6 months) samples were collected in 12 of the patients (5 females). MEASUREMENTS: Dimeric inhibin B was measured by double antibody enzyme-linked immunosorbent assay (ELISA). FSH and LH were measured by sensitive time-resolved immunofluorescence. RESULTS: Girls: Pretreatment inhibin B was slightly high in one girl but normal for age and sex in all others: median 16.1 (range 9.4-186.2) ng/l, median SD score +0.2 (-1.3 to +2.6). Inhibin B decreased to undetectable levels (< 8 ng/l) in 8/9 girls during treatment (P = 0.03), with no accompanying rise in FSH or LH. Post-treatment recovery of inhibin B was variable: median 16.1 (range < 8.0-44.2) ng/l, median SD score +0.1 (range < -2.4 to +1.8). Sustained undetectable inhibin B levels were observed in 2/5 girls with correspondingly elevated FSH concentrations (11.8 and 10.9 U/l). Boys: Inhibin B was normal for age and sex in all boys before treatment with no significant change during or after treatment (medians 93 ng/l, 85 ng/l and 94 ng/l, SD scores -0.3, -0.6 and -0.2, respectively). Inhibin B decreased to undetectable levels in one boy post-treatment with no accompanying increase in FSH or LH. CONCLUSIONS: In prepubertal girls with cancer, chemotherapy is associated with suppression of inhibin B, usually transient, which may indicate arrest of follicle development. Sustained suppression of inhibin B following treatment may be indicative of permanent ovarian damage. In prepubertal boys, chemotherapy had little immediate effect on Sertoli cell production of inhibin B, although one boy showed a delayed effect. Inhibin B, together with sensitive measurements of FSH, may be a potential marker of the gonadotoxic effects of chemotherapy in prepubertal children with cancer.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2026

Assessment of Genetic Diversity and Population Structure on Azadirachta indica A. Juss. in an Urban Metropolitan: Ahmedabad, India.

Azadirachta indica (A. indica) A. Juss., commonly known as Neem, is a valuable multipurpose tree with profound medicinal properties and socioeconomic importance, widely recognized since ancient Ayurvedic times. Despite its prominence, knowledge about its genetic diversity within the metropolitan area of Ahmedabad is limited. This study marks the first in-depth exploration of the genetic diversity and population structure of A. indica in Ahmedabad. The authenticity of the species was validated through DNA barcoding, and a Geographical Information System (GIS) was used to collect the samples. A total of 35 A. indica accessions were analyzed using five Inter Simple Sequence Repeat (ISSR) primers. Genetic diversity and population structure were evaluated using Inter Simple Sequence Repeat (ISSR) markers through polymorphism assessment, clustering, ordination, and Bayesian population structure analyses. ISSRs revealed a high level of polymorphism (75.66%), indicating substantial genetic variability among accessions. An analysis of genetic diversity indices revealed low to moderate diversity (Hs = 0.14, Ht = 0.217, I = 0.217). Analysis of Molecular Variance (AMOVA) analysis depicted 81% variation within the population and 19% among the population. Low to moderate genetic differentiation (Gst = 0.319) and moderate gene flow (Nm = 1.06) indicated that urban development has not hindered gene flow among populations. Mantel's test revealed a weak but significant correlation between genetic and geographic distances, suggesting limited isolation by distance. The estimated ΔK using STRUCTURE exhibited two subpopulations, representing two gene pools for A. indica accessions (K = 2). Collectively, these patterns indicate that urbanization has not severely disrupted genetic connectivity in A. indica, reflecting its resilience and adaptive potential in a metropolitan environment. These findings provide pivotal knowledge for further understanding the genetic diversity and population structure of A. indica in one of the fastest-growing cities in India, which can be utilized for new breeding programmes, sustainable development and future conservation strategies around the globe.

India↗

PubMed2002

Evolution of the organization for tropical studies.

The Organization for Tropical Studies (OTS)/Organización para Estudios Tropicales (OET) has evolved in many ways since its founding in 1963 as a non-profit consortium offering graduate courses and facilitating research in tropical ecology in Costa Rica. By 2002, its international membership included about 65 institutions, including four from Costa Rica. It had developed three Costa Rican field stations (La Selva, Las Cruces, and Palo Verde) with excellent facilities for teaching and research, and it was constructing a new Costa Rican office at the University of Costa Rica. Combinations of internal and external pressures influenced OTS to develop in new directions in the 1980s and 1990s. It became more diversified and more concerned with applied science in its traditional areas of graduate education and research facilitation. The Organization also evolved into new niches: more applied biology, professional education, environmental education and policy, conservation efforts, and an expanded geographic distribution to other Latin American countries. OTS was composed of changing combinations of people (Boards, members, staff) with evolving and competing priorities for limited financial resources. External environmental changes also shaped OTS's evolution. New problems of increased tropical deforestation, the emergence of the biodiversity "crisis" and conservation biology, global climate change, and calls for sustainable development affected OTS constituents and funding priorities of governments and foundations. Both internal and external pressures have in some cases demanded for OTS to improve its relationship with: Costa Rican biologists and their institutions, the Costa Rican government, and Costa Ricans living around the three OTS field stations.

Costa Rica↗

PubMed2005

Zeitgeist leadership.

Companies and leaders don't succeed or fail in a vacuum. When it comes to longterm success, the ability to understand and adapt to changing business conditions is at least as important as any particular personality trait or competency. A clear picture of how powerful the zeitgeist can be emerges from the authors' comprehensive study of the way the business landscape in the United States evolved, decade by decade, throughout the twentieth century. Six contextual factors in particular, they found, most affected the prospects for business: the level of government intervention in business, global events, demographics, shifts in social mores, developments in technology, and the strength or weakness of the labor movement. A lack of contextual sensitivity can trip up even the most brilliant executive. No less a luminary than Alfred P. Sloan was relieved of GM's day-to-day management in the 1930s because he was unwilling to meet with the new UAW. Conversely, an understanding of the zeitgeist can play a crucial but unheralded role in business performance. Jack Welch is widely credited with GE's remarkable success during the 1980s and 1990s, for example, but far less attention has been paid to his predecessor, the statesmanlike and prudent Reginald Jones, who sustained strong revenue and profit growth during the heavily regulated stagflation of the 1970s. To better understand this connection between business performance and context, the authors studied 1,000 great U.S. business leaders of the twentieth century and identified three distinct archetypes: Entrepreneurs, often ahead of their time, overcame dire challenges to build something new. Managers excelled at reading and exploiting the existing zeitgeist to grow their businesses. Leaders defied context to identify latent potential in businesses others considered mature, stagnant, or in decline. In every decade, all three archetypes were vital. It is the ongoing regeneration of this pattern in the business life cycle that ultimately sustains development and progress.

Administrative Personnel↗

PubMed1990

Clinical profile of patients with Chagas' disease before and during sustained ventricular tachycardia.

Sustained ventricular tachycardia was diagnosed in 15 patients undergoing ordinary activity with Chagas' disease seen at our Institute from 1978 to 1989. Palpitations were observed in 11 (66%) of the patients, dyspnea in 7 (46%), atypical chest pain in 5 (33%) and syncope in 2 (13%). Cardiac arrhythmia was detected in 4 (26%) on physical examination. The resting electrocardiogram showed premature ventricular contractions in 13 (86%) patients, ST-T changes in 12 (80%), left axis deviation in 9 (60%) and right bundle branch block in 4 (26%). Chest X-rays showed mild cardiomegaly in 8 (53%) and moderate cardiomegaly in 3 (20%) patients. Mild left ventricular dysfunction was detected echocardiographically in 1 (10%), moderate in 3 (30%) and severe in 1 (10%) of the 10 patients studied. During sustained ventricular tachycardia, dyspnea was found in 7 of 15 (46%) patients, palpitations in 6 (40%), atypical chest pain in 6 (40%), syncope in 1 (6%), systemic arterial hypotension in 3 (20%) and cardiogenic shock in 2 (13%). The electrocardiographic findings were as follows: mean heart rate was 201 bpm; mean QRS lengthening was 0.16 sec; right bundle branch block plus right axis deviation was seen in 5 of 15 (33%) patients; right bundle branch block plus left axis deviation in 4 (26%); and a positive concordance of all precordial leads in 5 (33%) patients. Based on these findings, we conclude that the majority of patients with Chagas' disease who develop sustained ventricular tachycardia do not have severe myocardial disease, show an uncommon electrocardiographic pattern of this arrhythmia, and most importantly, have a benign clinical course.

Adult↗

PubMed1999

Blood Pressure Monitoring. Task force V: White-coat hypertension.

TERMINOLOGY: Two terms are in current use to describe patients whose blood pressures are high only in a medical setting (white-coat hypertension and isolated office or clinic hypertension). The term white-coat effect is also commonly used to describe the pressor response to the clinic setting. DEFINITIONS: White-coat hypertension is generally defined as a persistently elevated clinic blood pressure in combination with a normal ambulatory blood pressure (ABP). There is disagreement regarding the optimal cutoff point for ABP. The white-coat effect is operationally defined as the difference between the clinic blood pressure and daytime ABP. PREVALENCE OF WHITE-COAT HYPERTENSION: This varies according to the definition of white-coat hypertension and the population studied, but is approximately 20% among mild hypertensives, and increases with age. METABOLIC AND BIOCHEMICAL ASPECTS: Authors of some studies have suggested that white-coat hypertension is associated with metabolic abnormalities such as hyperlipidemia that lead to an increase in cardiovascular risk, but most have not found this. TARGET-ORGAN DAMAGE: Several measures of target-organ damage have been compared among normotensives, white-coat hypertensives, and sustained hypertensives; these include left ventricular mass, microalbuminuria, and carotid atherosclerosis. In general, target-organ damage in white-coat hypertension is less than that in sustained hypertension, but in some studies it has been found to be more prevalent than in normotensives. MORBIDITY AND MORTALITY: Authors of a relatively small number of prospective studies have concluded that white-coat hypertensives have a lower risk of morbidity than do sustained hypertensives, but a larger number have drawn the more general conclusion that, when there is a discrepancy between the clinic blood pressure and ABP, the prognosis is more closely related to the ABP. MANAGEMENT: When white-coat hypertensives are prescribed antihypertensive medication there is usually a decrease in clinic blood pressure, but little or no change in ABP. Thus drug treatment is not necessarily indicated. Another issue is the follow-up of white-coat hypertensives; there is general agreement that blood pressure outside the office should be monitored indefinitely. Some patient may have been wrongly classified as white-coat hypertensives, and others may progress to develop sustained hypertension.

Antihypertensive Agents↗

PubMed1991

Identification of cytokines which enhance (CSF-1, IL-3) or restrict (IFN-gamma) growth of intramacrophage Listeria monocytogenes.

Murine peritoneal macrophages were isolated by adherence and their listericidal activity assessed in the presence or absence of selected cytokines. Untreated macrophages were not highly listericidal, showing moderate killing in the first 2 h after infection, and allowed progressive microbial growth thereafter (up to 9 h). Pre-treatment of cells with 10 to 100 U/ml of IFN-gamma allowed macrophages to develop sustained listericidal activity for the 9-h observation period, with a 2-log reduction of Listeria CFU per monolayer. Pulsing of cells with TNF-alpha alone did not result in enhanced microbicidal activity but TNF-alpha potentiated IFN-gamma-induced listericidal activity, resulting in high levels of killing when both cytokines were present. Conversely, macrophages pre-treated with interleukin-3 (IL-3) or colony-stimulating factor-1 (CSF-1) were found to be much more permissive for Listeria growth. Neither IL-3 nor CSF-1 abrogated IFN-gamma-induced listericidal activity. Moreover, neither IL-3 nor CSF-1 had any effect on the ability of macrophages to develop a respiratory burst following Listeria infection, as judged by H2O2 release following in vitro infection. Overall, these results suggest that different cytokines may have opposing effects on intracellular microbial growth, and that the balance of cytokine production in vivo may determine the resistance or susceptibility of the infected host.

Animals↗

PubMed2005

[Learning healthy living--health management in schools. Health promotion in schools with particular consideration of socially disadvantaged students].

"Learning to Live Healthy" is a cooperation project between the Central Association of Health Insurers and the Health Associations of Lower Saxony, Saxony-Anhalt and Rhineland-Palatinate. Our goal is to develop a healthy environment for all teachers and students in the "School Organization". Our focus lies -- more strongly than with earlier projects for school health promotion -- in the improvement of the health of teachers and non-teaching personnel. Not until their resources are strengthened and overwork/overload broken down, can resources be directed to health promotion for and with students, and health risks connected with social inequalities can be diminished. The project operates with the setting approach, and uses the principles of Workplace Health Management- Integration, Participation and Project Management. The project utilizes the instruments of project organization to jump-start the process of change in the School Organization, systematically, through goal-oriented action and sustainable development, thus improving the quality of education.

Cultural Deprivation↗

PubMed2005

Biotechnology-a sustainable alternative for chemical industry.

This review outlines the current and emerging applications of biotechnology, particularly in the production and processing of chemicals, for sustainable development. Biotechnology is "the application of scientific and engineering principles to the processing of materials by biological agents". Some of the defining technologies of modern biotechnology include genetic engineering; culture of recombinant microorganisms, cells of animals and plants; metabolic engineering; hybridoma technology; bioelectronics; nanobiotechnology; protein engineering; transgenic animals and plants; tissue and organ engineering; immunological assays; genomics and proteomics; bioseparations and bioreactor technologies. Environmental and economic benefits that biotechnology can offer in manufacturing, monitoring and waste management are highlighted. These benefits include the following: greatly reduced dependence on nonrenewable fuels and other resources; reduced potential for pollution of industrial processes and products; ability to safely destroy accumulated pollutants for remediation of the environment; improved economics of production; and sustainable production of existing and novel products.

Biotechnology↗

PubMed1983

Mechanical properties of rat cerebral arteries as studied by a sensitive device for recording of mechanical activity in isolated small blood vessels.

A sensitive device for recording of mechanical activity in isolated small blood vessels with calibres down to 100 microns is described. This equipment was used to examine the mechanical properties of rat cerebral arteries. The ultrastructure of the preparations was investigated by light-, transmission, and scanning electron-microscopy. In general the walls of the middle cerebral and basilar arteries consisted of 3 layers of smooth muscle cells, which occupied approximately 80% of the total wall thickness. The present technique preserved the integrity of the vessel wall and caused no observable damage to the smooth muscle or endothelial cells. Neither the basilar nor the middle cerebral arteries developed spontaneous phasic contractions under standard conditions. Potassium excess (124 mM) induced a biphasic contractile response characterized by a fast and partly transient increase in tension (phase A), followed by a slowly developing sustained contraction (phase B). The responses to K+ were strong, highly reproducible and not influenced by pH changes in the range 6.9-7.8, making K+-stimulation suitable for testing of vascular contractility. Length-tension measurements were performed on relaxed and K+-activated basilar arteries. The mechanical behaviour of the vessels conformed to a sliding-filament model of muscular contraction. Using the "Maxwell model" of a muscle, the length at which the contractile element produced maximum active tension was established. The passive wall tension at this length (approximately 1 mN/mm) averaged only about 20% of the total wall tension the arteries were capable of producing when activated by K+. Under isometric conditions the K+-contracted basilar artery developed a maximum active wall stress of approximately 240 mN/mm2. In the light of the mechanical data obtained from the length-tension measurements, the optimum resting wall tension for registration of vascular responses is discussed. It appears that the present in vitro system can be of great value in investigations of the smooth muscle function in small blood vessels.

Animals↗

PubMed2003

Sustainability concept for a newly built urban area in Malmö, Sweden.

National goals regarding sustainable development from the Swedish government were decisive in the planning process when the newly built city district Western Harbour was established in the city of Malmö, Sweden. A systems analysis was used as a tool for evaluating different collection and treatment systems. This type of analysis does not include more subjective factors such as acceptance of organic fertilizers based on human waste and user acceptance of collection schemes. These aspects, however, will often determine the success of a technical solution. When the system for collection and treatment of old organic waste and wastewater was designed, both subjective and objective factors were considered. This meant that a centralised solution for wastewater treatment was selected. In order to facilitate a more sustainable solution for sludge management a treatment process with recovery of phosphorus will have to be introduced. Organic waste is sorted out and treated in an anaerobic digestion process. Source sorting of solid organic waste has been difficult to implement in Sweden due to inadequate sorting discipline. As a consequence two relatively new systems are tested in the area. A comprehensive evaluation will be carried out during a period of two years.

Cities↗

PubMed1993

Risk for sustained amenorrhea in patients with systemic lupus erythematosus receiving intermittent pulse cyclophosphamide therapy.

OBJECTIVE: To determine the risk for secondary amenorrhea after pulse cyclophosphamide therapy in premenopausal women with systemic lupus erythematosus. DESIGN: Controlled, retrospective clinical study. SETTING: Government referral-based research hospital. PATIENTS: Thirty-nine women younger than 40 years treated with pulse cyclophosphamide therapy for active lupus nephritis or neuropsychiatric lupus. Sixteen women who received pulses of intravenous methylprednisolone were controls. INTERVENTIONS: Sixteen patients received pulse cyclophosphamide (0.5 to 1.0 g/m2 body surface area) monthly for a total of 7 doses (short-CY), and 23 patients received 15 or more doses (long-CY). Control patients were treated with monthly pulses of methylprednisolone (1.0 g/m2) for a total of nine doses. MEASUREMENTS: Rates of amenorrhea were evaluated according to duration of treatment (number of doses) and age at the initiation of pulse therapy. RESULTS: Two of 16 patients (12%) in the Short-CY group and 9 of 23 (39%) in the long-CY group developed sustained amenorrhea (P = 0.07). Rates of sustained amenorrhea (short- and long-CY) according to age at the start of pulse therapy were: < or = 25 years, 2/16 (12%); 26 to 30 years, 4/15 (27%); > or = 31 years, 5/8 (62%) (P = 0.04). The increased risk for sustained amenorrhea in patients treated with long-CY was most evident in patients older than 25 years (short-CY [2/12] compared with long-CY [7/11]; P = 0.03). Three other patients with short-CY had reversal of amenorrhea fewer than 12 months after cessation of therapy. Amenorrhea was not observed in any of the 16 control patients. CONCLUSIONS: Intermittent pulse cyclophosphamide therapy in patients with systemic lupus erythematosus is associated with sustained amenorrhea, which is related to both age and number of doses of cyclophosphamide.

Adult↗

PubMed1999

Vascular surgical society of great britain and ireland: transcranial doppler-directed dextran therapy in the prevention of postoperative carotid thrombosis

BACKGROUND: Evidence suggests that embolization precedes carotid thrombosis, a previously unpredictable event complicating 2-3 per cent of all carotid endarterectomies. It was hypothesized that dextran 40 therapy might prevent progression to complete thrombosis in high-risk patients. METHODS: Between October 1995 and July 1998, 400 consecutive patients were monitored following carotid endarterectomy using transcranial Doppler ultrasonography. Those with sustained embolization (more than 25 in 10 min) or those with emboli that distorted the middle cerebral artery waveform were commenced on an incremental dextran 40 infusion. RESULTS: Two hundred and sixteen patients (54 per cent) had one or more emboli detected (96 per cent within 2 h of flow restoration) but only 15 (4 per cent) required dextran therapy. Embolization ceased in each case although the dextran dose had to be adjusted in four. In one of the latter patients, embolization recurred on day 5 but was again controlled with high-dose dextran. Overall, the death and any stroke rate was 2 per cent and no patient suffered a stroke due to carotid thrombosis. CONCLUSION: A few patients develop sustained embolization following carotid endarterectomy which, in previous studies, has been shown to be highly predictive of carotid thrombosis. The authors' experience to date suggests that dextran can stop this phase of embolization and prevent progression to complete carotid thrombosis. However, the dose of dextran has to be adjusted in 25 per cent of patients (i.e. blind administration of dextran may not be effective) and, very rarely, embolization may recur later.

Journal Article↗

PubMed2001

Changing approaches to mountain watersheds management in mainland South and Southeast Asia.

Mountain watersheds, comprising a substantial proportion of national territories of countries in mainland South and Southeast Asia, are biophysical and socioeconomic entities, regulating the hydrological cycle, sequestrating carbon dioxide, and providing natural resources for the benefit of people living in and outside the watersheds. A review of the literature reveals that watersheds are undergoing degradation at varying rates caused by a myriad of factors ranging from national policies to farmers' socioeconomic conditions. Many agencies--governmental and private--have tried to address the problem in selected watersheds. Against the backdrop of the many causes of degradation, this study examines the evolving approaches to watershed management and development. Until the early 1990s, watershed management planning and implementation followed a highly centralized approach focused on heavily subsidized structural measures of soil conservation, planned and implemented without any consultation with the mainstream development agencies and local people. Watershed management was either the sole responsibility of specially created line agencies or a project authority established by external donors. As a consequence, the initiatives could not be continued or contribute to effective conservation of watersheds. Cognizant of this, emphasis has been laid on integrated, participatory approaches since the early 1990s. Based on an evaluation of experiences in mainland South and Southeast Asia, this study finds not much change in the way that management plans are being prepared and executed. The emergence of a multitude of independent watershed management agencies, with their own organizational structures and objectives and planning and implementation systems has resulted in watershed management endeavors that have been in complete disarray. Consistent with the principle of sustainable development, a real integrated, participatory approach requires area-specific conservation programs that are well incorporated into integrated socioeconomic development plans prepared and implemented by local line agencies in cooperation with nongovernment organizations (NGOs) and concerned people.

Agriculture↗

PubMed1994

A comparison of amiodarone and digoxin for treatment of supraventricular arrhythmias after cardiac surgery.

Despite the widespread use of amiodarone in non-surgical patients, its role in the management of supraventricular tachyarrhythmias after cardiac surgery is not clear. We set out to compare the relative efficacy of amiodarone and digoxin in the management of atrial fibrillation and flutter in the early postoperative period. This prospective randomised trial comprised 30 patients, previously in sinus rhythm, who developed sustained atrial fibrillation or flutter following myocardial revascularisation, valve surgery or combined procedures. Amiodarone was administered as an intravenous loading dose followed by a continuous infusion. Digoxin was given as an intravenous loading dose followed by oral maintenance therapy. Electrocardiographic and haemodynamic monitoring was continued for 24 h after the commencement of treatment. There was a marked reduction in heart rate in both groups, mainly in the first 6 h, from 146 to 89 beats per minute in the amiodarone group and from 144 to 95 in the digoxin group. At the end of the 24 h, one of the 15 patients in the amiodarone group and 3 of the 15 patients in the digoxin group remained in atrial fibrillation. No patient in either group developed adverse reactions. We conclude that intravenous amiodarone therapy is safe and at least as effective as digoxin in the initial management of arrhythmias after cardiac surgery.

Aged↗

PubMed1995

Kinase activation and smooth muscle contraction in the presence and absence of calcium.

PURPOSE: The intracellular signalling mechanisms that modulate the sustained vascular smooth muscle contractions that occur with vasospasm are not well understood. The purpose of this investigation was to examine cell signalling mechanisms that account for sustained vascular smooth muscle contraction, independent of increases in intracellular Ca2+ concentrations ([Ca2+]i). METHODS: Fresh bovine carotid artery smooth muscles contractile responses were examined in a muscle bath. [Ca2+]i was depleted by use of the extracellular Ca2+ chelator, ethylene glycol-bis(beta-aminoethylether) N,N,N',N'-tetraacetic acid and the intracellular chelator, 1,2-bis(2-aminophenoxy)ethane-N,N,N',N',-tetraacetic acid. RESULTS: In Ca(2+)-free conditions, depolarizing the membrane with high extracellular KCI failed to elicit a contraction. In addition, in Ca(2+)-free conditions the ([Ca2+]i) was less than 10 nmol/L as determined with the Ca(2+)-indicator, Fura 2. The protein kinase C (PKC) activator, phorbol 12, 13-dibutyrate (PDBu), induced slowly developing sustained contractions in bovine carotid artery smooth muscle, and the magnitude of the contractile response to PDBu (10 nmol/L to 10 mumol/L) was the same in the presence and absence of Ca2+. PDBu induced contractions in Ca(2+)-free conditions were not inhibited by the myosin light chain kinase inhibitor, ML-9 (50 mumol/L), but were inhibited by the PKC inhibitor, staurosporine (50 nmol/L). CONCLUSIONS: These data suggest that vascular smooth muscle contractions can occur under conditions where the [Ca2+]i is low and fixed and that these contractions may be mediated by PKC.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗

PubMed1999

PROFILE: Integrating Stressor and Response Monitoring into a Resource-Based Water-Quality Assessment Framework.

/ South African water law as well as the country's water resource management policies are currently under review. The Water Law Principles, which were established as part of this review process, indicate a commitment to sustainable development of water resources and the protection of an ecological "reserve." Such policy goals highlight the limitations of traditional and current water-quality management strategies, which rely on stressor monitoring and associated regulation of pollution. The concept of an assimilative capacity is central to the implementation of the current water-quality management approach. Weaknesses inherent in basing water management on the concept of assimilative capacity are discussed. Response monitoring is proposed as a way of addressing some of the weaknesses. Following a global trend, the new policy goals emphasize the need to protect rather than to use the ability of ecosystems to recover from disturbances. This necessitates the adoption of response measurements to quantify ecological condition and monitor ecological change. Response monitoring focuses on properties that are essential to the sustainability of the ecosystem. These monitoring tools can be used to establish natural ranges of ecological change within ecosystems, as well as to quantify conceptually acceptable and unacceptable ranges of change. Through a framework of biological criteria and biological impairment standards, the results of response monitoring can become an integral part of future water resource management strategies in South Africa. KEY WORDS: Stressor monitoring; Response monitoring; Assimilative capacity; Ecosystem stability; Resilience; Biocriteria

Journal Article↗

PubMed2006

Pectinase production by solid fermentation from Aspergillus niger by a new prescription experiment.

The Ordos Plateau in China is covered with up to 300,000 ha of peashrub (Caragana) which is the dominant natural vegetation and ideal for fodder production. To exploit peashrub fodder, it is crucially important to optimize the culture conditions, especially culture substrate to produce pectinase complex. In this study, a new prescription process was developed. The process, based on a uniform experimental design, first optimizes the solid substrate and second, after incubation, applies two different temperature treatments (30 degrees C for the first 30 h and 23 degrees C for the second 42 h) in the fermentation process. A multivariate regression analysis is applied to a number of independent variables (water, wheat bran, rice dextrose, ammonium sulfate, and Tween 80) to develop a predictive model of pectinase activity. A second-degree polynomial model is developed which accounts for an excellent proportion of the explained variation (R(2)=97.7%). Using unconstrained mathematical programming, an optimized substrate prescription for pectinase production is subsequently developed. The mathematical analysis revealed that the optimal formula for pectinase production from Aspergillus niger by solid fermentation under the conditions of natural aeration, natural substrate pH (about 6.5), and environmental humidity of 60% is rice dextrose 8%, wheat bran 24%, ammonium sulfate ((NH(4))(2)SO(4)) 6%, and water 61%. Tween 80 was found to have a negative effect on the production of pectinase in solid substrate. With this substrate prescription, pectinase produced by solid fermentation of A. niger reached 36.3 IU/(gDM). Goats fed on the pectinase complex obtain an incremental increase of 0.47 kg day(-1) during the initial 25 days of feeding, which is a very promising new feeding prospect for the local peashrub. It is concluded that the new formula may be very useful for the sustainable development of arid and semiarid pastures such as those of the Ordos Plateau.

Animal Feed↗