High safety margins to drought-induced hydraulic failure found in five pasture grasses

Determining the relationship between reductions in stomatal conductance (g_s ) and leaf water transport during dehydration is key to understanding plant drought responses. While numerous studies have analysed the hydraulic function of woody species, minimal research has been conducted on grasses. Here, we sought to characterize hydraulic vulnerability in five widely-occurring pasture grasses (including both C3 and C4 grasses) and determine whether reductions in g_s and leaf hydraulic conductance (K_leaf ) during dehydration could be attributed to xylem embolism. Using the optical vulnerability (OV) technique, we found that all species were highly resistant to xylem embolism when compared to other herbaceous angiosperms, with 50% xylem embolism (P_X50 ) occurring at xylem pressures ranging from -4.4 to -6.1 MPa. We observed similar reductions in g_s and K_leaf under mild water stress for all species, occurring well before P_X50 . The onset of xylem embolism (P_X12 ) occurred consistently after stomatal closure and 90% reduction of K_leaf . Our results suggest that factors other than xylem embolism are responsible for the majority of reductions in g_s and K_leaf during drought and reductions in the productivity of pasture species under moderate drought may not be driven by embolism.

Pastures and Climate Extremes: Impacts of Cool Season Warming and Drought on the Productivity of Key Pasture Species in a Field Experiment

Shifts in the timing, intensity and/or frequency of climate extremes, such as severe drought and heatwaves, can generate sustained shifts in ecosystem function with important ecological and economic impacts for rangelands and managed pastures. The Pastures and Climate Extremes experiment (PACE) in Southeast Australia was designed to investigate the impacts of a severe winter/spring drought (60% rainfall reduction) and, for a subset of species, a factorial combination of drought and elevated temperature (ambient +3°C) on pasture productivity. The experiment included nine common pasture and Australian rangeland species from three plant functional groups (C3 grasses, C4 grasses and legumes) planted in monoculture. Winter/spring drought resulted in productivity declines of 45% on average and up to 74% for the most affected species (Digitaria eriantha) during the 6-month treatment period, with eight of the nine species exhibiting significant yield reductions. Despite considerable variation in species' sensitivity to drought, C4 grasses were more strongly affected by this treatment than C3 grasses or legumes. Warming also had negative effects on cool-season productivity, associated at least partially with exceedance of optimum growth temperatures in spring and indirect effects on soil water content. The combination of winter/spring drought and year-round warming resulted in the greatest yield reductions. We identified responses that were either additive (Festuca), or less-than-additive (Medicago), where warming reduced the magnitude of drought effects. Results from this study highlight the sensitivity of diverse pasture species to increases in winter and spring drought severity similar to those predicted for this region, and that anticipated benefits of cool-season warming are unlikely to be realized. Overall, the substantial negative impacts on productivity suggest that future, warmer, drier climates will result in shortfalls in cool-season forage availability, with profound implications for the livestock industry and natural grazer communities.

Comparative evaluation of the efficacy of tricalcium phosphate, calcium sodium phosphosilicate, and casein phosphopeptide - amorphous calcium phosphate in reducing streptococcus mutans levels in saliva

BACKGROUND

There are only limited studies that have determined the antibacterial effects of various remineralizing agents that can be beneficial to children.

AIM

The aim of this study is to compare the efficacy of tricalcium phosphate (TCP), calcium sodium phosphosilicate (CSP), and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) enhanced with fluoride in reducing the Streptococcus mutans (SM) levels in saliva of children.

MATERIALS AND METHODS

Out of 245 children, 120 of them with SM colony forming units (CFU)/ml in the range of 104-106/ml of saliva were assigned to four groups: (I) TCP; (II) CSP; (III) CPP-ACP enhanced with fluoride; and (IV) control. Salivary samples were collected at intervals of 1 week, 2 weeks, and 4 weeks and the number of CFU/ml of SM in saliva were counted post 48 hour incubation.

RESULTS

After 1 week, 2 weeks, and 4 weeks, there was a significant reduction in the mean score of SM (P < 0.05). The maximum reduction in the CFU/ml in the saliva was seen in the 1st week after the commencement of the brushing in all the three test groups. Group III children demonstrated the maximum reduction of 15 × 105 CFU/ml, followed by Group II children with 10 × 105 CFU/ml.

CONCLUSIONS

Twice daily use of CPP-ACP with fluoride, CSP, and TCP caused a significant reduction in the levels of SM in saliva.

Application of the European-modified dental clinical learning environment inventory (DECLEI) in dental schools in Riyadh, Saudi Arabia

AIM

The aim of this study was to evaluate undergraduate dental students' self-perceptions of their clinical dental environment using a valid, concise and more practical version of the Dental Clinical Learning Environment Inventory (DECLEI) questionnaire.

MATERIALS AND METHODS

The 24-item DECLEI was self-administered to fourth- and fifth-year undergraduate dental students from public and private dental schools in Riyadh, Saudi Arabia, during the 2014-2015 academic year. Factor analysis revealed three underlying factors associated with the clinical learning environment. Independent sample t-tests were used to evaluate any associations amongst the items, the factors, the total DECLEI score and other demographic variables. For the scoring system, 6-point Likert scale responses were scored on a 100% scale ranging from excellent to poor.

RESULTS

The mean DECLEI total score was 64.1 (good) of 100. Amongst the factors, the highest mean score, 71.3 (good), was obtained for the patient interactions and professionalism, and the lowest mean score, 50.2 (moderate), was observed for all the negatively worded statements in the DECLEI. The instrument exhibited good discriminant validity as it was able to record significant differences between genders and between public and private institutions in the total DECLEI, the factors and most of the items scored.

CONCLUSIONS

The new DECLEI scale identified several areas of strength and some aspects that could be improved. Overall, the dental students rated the clinical undergraduate programme as more positive than negative.

Intracorporeal electrokinetic lithotripsy: an advancement in minimally invasive management of parotid duct calculus

Background:

Symptomatic salivary stones in the middle or proximal parotid duct have previously been treated by gland excision, which is associated with a 3–7 per cent risk to the facial nerve. Minimally invasive approaches to the management of salivary duct calculi have been devised over the past decade. Fluoroscopically guided basket retrieval, lithotripsy and intra-oral stone removal under general anaesthesia have found favour with most surgeons. Endoscopically controlled intracorporeal shock wave lithotripsy using the pneumoblastic lithotripter has been replaced by electrohydraulic lithotripsy (used in sialolith treatment).

Method:

The electrokinetic lithotripter is normally used for the treatment of lower ureteric stones, and has the benefit of minimal concomitant tissue damage. We have extended its use to the treatment of parotid duct calculi. We present initial results for its use in the treatment of a proximal parotid duct stone.

Result:

Application of the shock wave to the stone under direct vision avoided injury to the duct or to any local structure. The patient made an uneventful recovery and was asymptomatic after 18 months' follow up.

Conclusion:

Continuous, endoscopically monitored electrokinetic lithotripsy with good irrigation gives a well illuminated field and absolute delivery of energy to the target. It avoids the side effects caused by impact of the shock wave on the parotid duct and adjacent anatomical structures, thereby making it a safer procedure.

Dose-escalated simultaneous integrated-boost treatment of prostate cancer patients via helical tomotherapy

PURPOSE

The goal of this work was to assess the feasibility of moderately hypofractionated simultaneous integrated-boost intensity-modulated radiotherapy (SIB-IMRT) with helical tomotherapy in patients with localized prostate cancer regarding acute side effects and dose-volume histogram data (DVH data).

METHODS

Acute side effects and DVH data were evaluated of the first 40 intermediate risk prostate cancer patients treated with a definitive daily image-guided SIB-IMRT protocol via helical tomotherapy in our department. The planning target volume including the prostate and the base of the seminal vesicles with safety margins was treated with 70 Gy in 35 fractions. The boost volume containing the prostate and 3 mm safety margins (5 mm craniocaudal) was treated as SIB to a total dose of 76 Gy (2.17 Gy per fraction). Planning constraints for the anterior rectal wall were set in order not to exceed the dose of 76 Gy prescribed to the boost volume. Acute toxicity was evaluated prospectively using a modified CTCAE (Common Terminology Criteria for Adverse Events) score.

RESULTS

SIB-IMRT allowed good rectal sparing, although the full boost dose was permitted to the anterior rectal wall. Median rectum dose was 38 Gy in all patients and the median volumes receiving at least 65 Gy (V65), 70 Gy (V70), and 75 Gy (V75) were 13.5%, 9%, and 3%, respectively. No grade 4 toxicity was observed. Acute grade 3 toxicity was observed in 20% of patients involving nocturia only. Grade 2 acute intestinal and urological side effects occurred in 25% and 57.5%, respectively. No correlation was found between acute toxicity and the DVH data.

CONCLUSION

This institutional SIB-IMRT protocol using daily image guidance as a precondition for smaller safety margins allows dose escalation to the prostate without increasing acute toxicity.

Multidrug-resistant tuberculosis: a review of the 23 cases treated by the Saint-Pierre University Hospital (Brussels)

For about fifteen years, Belgium, as other developed countries, has been confronted with multidrug-resistant tuberculosis (MDR-TB). The treatment of MDR-TB is complex, associating several antibiotics and causing multiple adverse effects. The aim of this study is to report our experience with MDR-TB at the Saint-Pierre University Hospital in Brussels.

Ten-year data on 138 patients with endometrial carcinoma and postoperative vaginal brachytherapy alone: No need for external-beam radiotherapy in low and intermediate risk patients

OBJECTIVE

To evaluate long-term outcome, risk factors, and causes of death in stage I-IIIA endometrial carcinoma (EC) patients treated only with adjuvant vaginal brachytherapy (VB) and to clarify for which subgroups of patients it is safe to omit external-beam radiotherapy (EBRT).

METHODS

Out of 224 EC patients receiving postoperative radiotherapy between 1990 and 2002, 138 had VB alone in curative intent (FIGO [2002]: 85%I, 12%II, 3%IIIA; 18 low risk [IA G1-2, IB G1], 103 intermediate risk [IB G2-3, IC G1-2, IIA-B G1-2], 17 high risk [IC G3, IIIA]). After surgery+/-lymphadenectomy, HDR-brachytherapy prescription (in 95.7% of patients) was 3x10 Gy to the surface or 3x5 Gy at 5 mm tissue depths.

RESULTS

Median follow-up was 107 months (range 3-185). Three intermediate and 7 high risk-patients relapsed. The 10-year vaginal control was 99.2%, locoregional control was 95.2% (low/intermediate/high risk: 100%/98.9%/68.8%), and disease-free survival (DFS) was 91.7% (100%/96.8%/55.2%). Risk factors for poor DFS were lymphovascular space invasion, > or = 50% myometrial invasion (univariate, p<0.05), pathological FIGO-stage, and grade 3 (uni-/multivariate, p<0.05). Leading causes of deaths (n=41) were cardiovascular disease (29%) and other malignancies (24%) ahead of EC (19.5%). The 10-year overall survival was 68.5% and the disease-specific survival was 92.4%. Thirty-five secondary tumors in 31 patients led to a higher actuarial death rate (10-year 9.9%, 15-year 17.7%) than EC (7.6%).

CONCLUSIONS

Restricting adjuvant therapy to VB alone seems to be safe in low and intermediate risk EC and can be recommended. As death rarely relates to early-stage EC, value of adjuvant therapy is probably better reflected by DFS rather than by overall survival.

Lung cancer in Mayak workers: interaction of smoking and plutonium exposure

Lung cancer mortality among 5,058 male workers of the Mayak Production Association has been analyzed with emphasis on the interaction of smoking and radiation exposure by using the two-step clonal expansion (TSCE) model of carcinogenesis. The cohort consists of all Mayak workers with known smoking status, who were employed in the period 1948-1972, and who either had the plutonium concentration in urine measured or who worked in the reactors, where plutonium exposure was negligible. Those who died during the first two years after the first urine sampling were excluded. The follow-up extended until the end of 1998. During this time, 2,176 workers died, including 244 lung cancer cases. Mayak workers were exposed to external (gamma and neutron) radiation, and in the radiochemical and plutonium plants to plutonium. In the preferred TSCE model, internal radiation and smoking act on the clonal expansion of pre-carcinogenic clones. Assuming a plutonium radiation weighting factor of 20, the excess relative risk per lung dose was estimated to be 0.11 (95% CI: 0.08; 0.17) Sv(-1). Most of the lung cancer deaths are found to be due to smoking. The second main factor is the interaction of smoking and internal radiation. The model is sub-multiplicative in relative risks due to smoking and radiation. In a multiplicative version of the TSCE model, internal radiation acts on initiation and transformation rates. This model version agrees with conventional epidemiological risk models, because it also suggests a higher risk estimate than the preferred TSCE model. However, it fits the data less well than the preferred model.

Bi-lamellar lower eyelid reconstruction with superficial temporal artery island flap and hard palate muco-periosteal free graft

Three cases of single stage, bi-lamellar reconstruction of full-thickness, horizontal, lateral three-quarter lower eyelid defects using pedicled island flaps of adjacent vascular territories and hard palate muco-periosteal graft are being presented.

All cases were done for Basal Cell Carcinoma of the region. While the island flaps allowed for a simple, single stage reconstruction of the external lamella, the hard palate muco-periosteal graft, by virtue of its inherent resilience and a rich glandular component, took well and provided for a good functional and aesthetic result.

The follow-up ranged from 6 to 40 months and the final result has been oncologically, functionally and aesthetically satisfactory.

[Moulds asthma]

Mould allergy revealed by skin prick tests or by measuring specific IgE (RAST), is frequently diagnosed throughout the world. It is associated to clinical asthma, sometimes severe. Thanks to the know how of teams of specialists, surveys are carried out in home-, work- and school environments, and calendars of moulds found in our country are regularly updated. This allows practitioners to determine specific sensitisation tests (selection of skin prick tests, and RAS tests), and helps them play a role in the diagnosis strategy and the recommendations for necessary eviction and building sanitation measures. These measures are all the more important as until now standardised extracts for specific hyposensitisation to moulds are not yet available.

Biological parameters for lung cancer in mathematical models of carcinogenesis

Applications of the two-step model of carcinogenesis with clonal expansion (TSCE) to lung cancer data are reviewed, including those on atomic bomb survivors from Hiroshima and Nagasaki. British doctors, Colorado Plateau miners and Chinese tin miners. Different sets of identifiable model parameters are used in the literature. The parameter set which could be determined with the lowest uncertainty consists of the net proliferation rate gamma of intermediate cells, the hazard h55 at an intermediate age and the hazard h(infinity) at an asymptotically large age. Also, the values of these three parameters obtained in the various studies are more consistent than other identifiable combinations of the biological parameters. Based on representative results for these three parameters, implications for the biological parameters in the TSCE model are derived.

White-sided dolphin metallothioneins: purification, characterisation and potential role

Metallothioneins (MTs) were characterised in the kidneys of a white-sided dolphin Lagenorhynchus acutus stranded along the Belgian coast, displaying high levels of cadmium (Cd) and mercury (Hg) in liver and kidney. The protein has two isoforms: MT-1 and MT-2. MT-1 binds Cu, Zn, Hg and Cd, while MT-2 only binds Zn, Hg and Cd. This suggests different metabolic functions for the two isoforms: MT-1 is mainly involved in Cu homeostasis; MT-2, which was four-fold more abundant than MT-1, detoxifies most of the accumulated cadmium.

Asymptomatic malarial parasitaemia in Tamil Nadu

AIM

The aim of the study was to determine the community prevalence of asymptomatic malarial parasitaemia in the state of Tamil Nadu.

METHODS

Free medical camps were organised in three randomly selected districts of Tamil Nadu, namely Dindigul, Ramnad and Thanjavur districts in November, 1997. Proportionate to population size cluster survey method was followed to collect peripheral blood smear by finger prick from 30 clusters in each district. Fifteen households were randomly selected from each district with the target age group of 15-45 years. Peripheral blood smears were stained by Leishman's stain and the slides were examined end to end by two independent experts to diagnose malarial parasites.

RESULTS

The male:female ratio of the population studied was 1:1.6. Asymptomatic malaria was identified in 17 out of 569 individuals screened with a positive rate of 2.9% (CI 1.5-4.3). Out of the 17 malarial positive peripheral smears 15 were P. vivax and only two were P. falciparum with the predominance of gametocyte stage.

CONCLUSION

This study reaffirms the prevalence of asymptomatic malaria in Tamil Nadu especially with P. vivax.

Cytokines and the malnutrition of chronic renal failure

Malnutrition in uremic patients remains one of the major causes of morbidity and mortality. Its mediators remain largely unknown. Uremia is characterized by changes in circulating levels of catabolic cytokines and anabolic growth factors. The aim of this study was to investigate whether these changes are associated with the malnutrition of patients with chronic renal failure (CRF). We have studied the prevalence of malnutrition in a small group of patients (n = 20) with CRF (serum creatinine = 551 +/- 105 mumol/l, mean +/- SD) and 25 age-matched controls. Nutritional status was assessed by dietary diaries, subjective global assessment (SGA), and by measurement of anthropometric parameters. Regression analysis was applied to examine the relationship between biochemical and anthropometric parameters. Simultaneously, we have investigated changes in the circulating levels of catabolic cytokines [tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1 beta and IL-6] and an anabolic growth factor [insulin-like growth factor-I (IGF-I)]. We observed a high prevalence of malnutrition as judged initially by SGA: 50% moderately malnourished and 15% severely malnourished. This was confirmed by anthropometric measurements. We noted a significant reduction in both triceps skinfold thickness (TST; 35% of patients < 25th centile) and midarm muscle circumference (MAMC, 65% of patients < 25th centile). We also noted a reduction in serum IGF-I in malnourished patients (IGF-I in well-nourished patients = 207 +/- 48 micrograms/l, in malnourished patients = 133 +/- 33 micrograms/l, p < 0.01). IGF-I correlated with TST (r = 0.71, p < 0.001) and MAMC (r = 0.47, p < 0.05). IGF-I had a high predictive value for TST (R2 = 51%, p < 0.001). In contrast, TNF-alpha levels were higher in malnourished patients: 19.5 +/- 30 pg/ml compared to 3.9 +/- 8 pg/ml in healthy patients (p < 0.001) and TNF-alpha showed a negative correlation with MAMC (r = -0.69, p < 0.01; R2 = 47%, p < 0.01). IL-1 beta levels were higher in CRF than in controls but did not correlate with nutritional parameters. No significant changes could be detected in serum IL-6. A significant percentage of predialysis patients with CRF suffer from some degree of malnutrition. This may be attributed in part to a fall in circulating anabolic growth factors and an increase in catabolic cytokines.

Nutritional profile of continuous ambulatory peritoneal dialysis patients

Undernutrition in dialysis patients contributes to their morbidity and mortality. This is a cross-sectional study of the nutritional status of 61 patients treated with continuous ambulatory peritoneal dialysis (CAPD). They were studied with emphasis on assessment of their nutritional intake, anthropometric measurements, and evaluation of biochemical parameters. The correlation between the rate of CAPD peritonitis and these measurements was also examined. The majority of the patients (63.1%) had inadequate protein intake ( < or = 1.2 g/kg/day). A comparable percentage had a low energy intake ( < or = 30 kcal/kg/day). Moderate malnutrition, as assessed by a low triceps skinfold thickness (TST) or a reduced midarm muscle circumference (MAMC) of < or = 20th percentile, was detected in 52% and 39% of the patients, respectively. Severe malnutrition (TST or MAMC < or = 10th percentile) was present in 36% of the patients. The serum insulin-like growth factor I (IGF-I) proved to be the most useful biochemical marker of malnutrition. It showed a positive correlation with TST (r = 0.325; p < 0.05). No significant correlation was observed with other short-life proteins such a transferrin or prealbumin. However, stepwise regression analysis showed the predictive value of serum IGF-I for anthropometric values to be low (adjusted R2 = 34.6%). Wasted patients did not appear to have more infections when compared to their healthier counterparts. However, a weak correlation was observed between TST and the number of peritonitis episodes.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of thyroid hormone in intermediary metabolism of propranolol or alloxan-treated Calotes versicolor

Administration of L-thyroxine (T4) to thyroidectomized Calotes versicolor significantly increased the activity of glucose-6-phosphatase (G-6-Pase) (liver and kidney), the concentrations of blood glucose and total protein (liver and kidney), and decreased hepatic cholesterol when compared to thyroidectomized lizards. Propranolol injections in thyroidectomized lizards increased the cholesterol concentration and did not change the other parameters. The activity of G-6-Pase and blood glucose content was stimulated, whereas the total protein and cholesterol contents were decreased after alloxan treatment. Administration of T4 to thyroidectomized animals pretreated with propranolol or alloxan significantly elevated the activity of G-6-Pase, the concentrations of blood glucose, and total protein, and reduced hepatic cholesterol level when compared to drug-treated lizards. From the results, it is evident that thyroid hormone has an independent stimulatory influence on intermediary metabolism in C. versicolor irrespective of the involvement of adrenaline or insulin.

A comparison of the effects of corticosterone and cortisol on intermediary metabolism of Calotes versicolor

Corticosterone and cortisol administered to Calotes versicolor significantly increased the concentrations of blood glucose and urea (liver and kidney), the specific activities of glucose-6-phosphatase (liver and kidney), and glutamic oxaloacetic transaminase (liver and heart); they markedly reduced hepatic cholesterol level and did not change the activities of acid phosphatase (liver and kidney) and glutamic pyruvic transaminase (liver), when compared to vehicle-treated controls.

IGF-I, a marker of undernutrition in hemodialysis patients

Early detection and treatment of malnutrition in patients on hemodialysis (HD) is hampered by lack of a sensitive biochemical marker. We compared the value of serum insulin-like growth factor-I (IGF-I) with other biochemical indices in detecting malnutrition in 61 HD patients. Protein and energy intakes were low in the majority of patients. Of all patients, 59.6% had severe reduction in triceps skinfold thickness (TSF thickness, less than or equal to 60% of normal), whereas midarm muscle circumference (MAMC) was mildly reduced (less than or equal to 90%) in 23%. Serum IGF-I proved superior to the other indices in predicting TSF thickness. A serum IGF-I concentration of 300 micrograms/L discriminated between wasted (TSF thickness less than or equal to 60%) and robust patients. In 16 patients with a history of recent infection, IGF-I was significantly reduced well before changes in anthropometric measurements could be detected. IGF-I is a useful and early marker of undernutrition in HD patients.

Intermediary metabolism in a lizard, Calotes versicolor: role of thyroid hormones

In Calotes versicolor, thyroidectomy did not alter the blood glucose level, lactate dehydrogenase (LDH liver and heart), acid phosphatase (Ac.Pase liver and kidney), and alkaline phosphatase (Alk.Pase liver and kidney) activities; significantly decreased the activities of glucose-6-phosphatase (G-6-Pase liver and kidney), glutamic oxaloacetic transaminase (GOT liver and heart), glutamic pyruvic transaminase (GPT liver), and urea concentration (liver and kidney); and increased liver cholesterol when compared to sham-operated controls. Administration of L-thyroxine (L-T4) or triiodo-L-thyronine (L-T3) to thyroidectomized lizards significantly stimulated the activities of G-6-Pase, Ac.Pase, GOT and GPT, concentration of glucose and urea, and decreased the cholesterol level. While the activities of all the enzymes studied and cholesterol level remain unchanged, glucose and urea levels decreased and increased, respectively, in thyroidectomized animals treated with actinomycin D. Chloramphenicol treatment did not affect any of the parameters studied. Simultaneous injections of actinomycin D or chloramphenicol with L-T4 prevented the hormone-stimulated activities of Ac.Pase, GOT, and GPT while the activities of LDH, G-6-Pase, Alk.Pase, glucose, urea, and cholesterol levels remain unchanged.

[Quantitative changes of rat's alpha 2 macroglobulin concentration by influence of carbon tetrachloride (author's transl)]

We examined the influence of carbon tetrachloride on the rat liver by means of some biological parameters (body mass, GPT-activity, time of hexobarbital narcosis, aminophenazone demethylation) in comparison to the relative concentration of alpha 2 AP under conditions of a long time experiment (8 weeks). The results show, that merely the alpha 2 AP is altered significant in test groups after 1 d of treatment in comparison to the other parameters. Afterwards, under lasting carbon tetrachloride influence the macroglobulin decreases below normal levels. The potential diagnostic value of the alpha 2 AP for toxicological examinations is discussed.