Grassland cover declined in Southern Africa but increased in other African subcontinents in early twenty-first century.

The African continent has the most extensive grassland cover in the world, providing valuable ecosystem services. African grasslands, like other continental grasslands, are prone to various anthropogenic disturbances and climate, and require data-driven monitoring for efficient functioning and service delivery. Yet, knowledge of how the African grassland cover has changed in the past years is lacking, especially at the subcontinent level, due to lack of relevant long-term, Africa-wide observations and experiments. In this study, we used Moderate Resolution Imaging Spectroradiometer (MODIS) Land Cover Type (MCD12Q1) data spanning 2001 to 2017 to conduct land use land cover (LULC) change analyses and map grassland distribution in Africa. Specifically, we assessed the changes in grassland cover across and within African subcontinents over three periods (2001-2013, 2013-2017, and 2001-2017). We found that the African grassland cover was 16,777,765.5 km2, 16,999,468.25 km2, and 16,968,304.25 km2 in 2001, 2013, and 2017, respectively. There were net gain (1.32%) and net loss (- 0.19%) during 2001-2013 and 2013-2017 periods, respectively, and the annual rate of change during these periods were 0.11% and - 0.05%, respectively. Generally, the African grassland cover increased by 1.14% (0.07% per annum) over the entire study period (2001-2017) at the expense of forestland, cropland, and built-up areas. The East and West African grassland cover reduced by 0.07% (- 0.02% per annum) and 1.35% (- 0.34% per annum), respectively from 2013 to 2017 but increased in other periods. On the other hand, the grassland cover in North and Central Africa increased throughout the three periods while that of Southern Africa decreased over the three periods. Overall, the net gains in the grassland cover of other African subcontinents offset the loss in Southern Africa and promoted the overall gain across Africa. This study underscores the need for continuous monitoring of African grasslands and the causes of their changes for efficient delivery of ecosystem services.

Predicted range shifts of invasive giant hogweed (Heracleum mantegazzianum) in Europe.

Heracleum mantegazzianum Sommier & Levier (Giant hogweed) has spread across Europe after its introduction as an ornamental from the native range in the Western Greater Caucasus. In addition to its invasive capability, H. mantegazzianum reduces the alpha diversity of native species in the non-native range and can cause second-degree burns when its phytotoxic sap contacts the skin upon exposure to sunlight. Previous studies on H. mantegazzianum distribution focused on individual countries, therefore we know little about the potential shift of the species distribution under changing climate at the continental scale. To fill that gap in the current knowledge, we aimed to (i) identify the most important climatic factors for the distribution of H. mantegazzianum in Europe, (ii) recognize areas that will be suitable and unsuitable for future climate scenarios to prioritize management action. Our study showed that the mean temperature of the coldest quarter (bio11) and temperature annual range (bio7) were the most important bioclimatic variables predicting the suitable habitat of the species in Europe. For all scenarios, we found that the majority of the range changes expected by 2100 will occur as early as 2041. We predicted an overall decrease in climatically suitable area for H. mantegazzianum under climate change with over three quarters (i.e. 94%) of the suitable area reduced under the Shared Socioeconomic Pathway (SSP) 585 in 2100. However, under the same scenario, climate conditions will likely favour the expansion (i.e. 20%) of H. mantegazzianum in northern Europe. The results from the present study will help in developing a climate change-integrated management strategy, most especially in northern Europe where range expansion is predicted.

Toxicity assessment of sub-acute and sub-chronic oral administration and diuretic potential of aqueous extract of Hibiscus sabdariffa calyces.

BACKGROUND: Food and herbal usage of Hibiscus sabdariffa (HS) is attaining improved global relevance and acceptance without recourse to its potential toxic effects. This study investigated the safety profile of acute, sub-acute, sub-chronic administrations and diuretic potential of aqueous extract of Hibiscus sabdariffa calyces (AEHSC). METHOD: Acute oral toxicity, sub-acute and sub-chronic toxicity as well as diuretic studies were carried out on HS. A total of 20 Wistar rats were used for each toxicity study and assigned into four groups of five rats. The extract was administered as a single daily dose of 125, 250 and 500 mg/kg body weight (bwt) for 28 and 90 days respectively. To evaluate diuretic activity, 25 rats were divided into five groups of five rats and administered normal saline, hydrochlorothiazide 10 mg/kg, AEHSC 67.5, 125 and 250 mg/kg via the oral route. Urine sample was collected after 18 h, volume measured and concentration of electrolytes analyzed. The hematological and biochemical parameters were evaluated as well as the histopathology of kidney and liver. RESULTS: The acute oral toxicity was found to be >2000 mg/kg. AEHSC did not alter concentration of WBC, MCV, MCHC, lymphocyte as well as total and direct bilirubin in the sub-acute study. However, AEHSC significantly (p < 0.05) increased total protein, albumin, globulin, Na+, Cl-, HCO3 - and platelet levels, while levels of uric acid, creatinine, K+, RBC, Hb, total cholesterol, triglycerides, LDL-C, HDL-C and atherogenic index were decreased significantly (p < 0.05). In the sub-chronic study, AEHSC significantly (p < 0.05) increased the levels of globulin, urea, creatinine, MCH and atherogenic index. The concentrations of uric acid, WBC, platelets and HDL-C were significantly (p < 0.05) decreased. In both the sub-acute and sub-chronic studies, activities of ALP, ALT, AST, GGT and LDH in selected organs were altered without significant increase (P < 0.05) in activity of these enzymes in the serum. The AEHSC at all the doses showed remarkable diuretic activity during 18 h period comparable to hydrochlorothiazide. The extract also showed a non-dose-dependent increase in excretion of electrolytes. Histological analysis of sections of the liver and kidney for both sub-acute and sub-chronic studies showed normal histology comparable to the control group. CONCLUSION: This study revealed AEHSC has some toxic effects in rats on sub-chronic administration. In addition, the extracts produced a significant diuretic activity. Hence, prolonged oral consumption of the extract may not be recommended.

Fertility enhancing activity and toxicity profile of aqueous extract of Chasmanthera dependens roots in male rats.

This study evaluated the fertility-enhancing activity and safety of aqueous extract of Chasmanthera dependens root (AECDR) in male rats. In the fertility study, twenty, sodium arsenite (10 mg/kg) body weight (BW)-treated male rats (171.02 ± 3.36 g), assigned into four groups (I-IV), received 1 ml of distilled water (DW), 25, 50 and 100 mg/kg BW of AECDR for 60 days, whereas the control received DW. After 7 days of pairing with female rats (153.67 ± 2.24 g), spermatogenic, fertility, testicular function indices and enzymatic antioxidant activities were evaluated. The animal groupings in the toxicity study were similar to the fertility study except no administration of sodium arsenite. Sodium arsenite treatment-related decreases (p < .05) in the semen and sperm parameters, testicular function indices, antioxidant activities and female rat fertility indices were reversed/ameliorated by AECDR. AECDR significantly altered the function indices of the liver and kidney and the lipid profile and selectively altered the haematological parameters. There was no treatment-related histoarchitectural changes in the organs. Overall, the aqueous extract of C. dependens roots exhibited pro-spermatogenic, fertility enhancing, antioxidant and androgenic activities in male rats. It also exhibited functional toxicity. Therefore, the chronic use of AECDR may not be completely safe as oral remedy.

Garcinia kola seeds: is the aqueous extract a true aphrodisiac in male Wistar rats?

The age long acclaimed aphrodisiac potentials of Garcinia kola seeds in some parts of Western Nigeria has not been substantiated with scientific evidence. In this study, we have decided to evaluate the effect of aqueous seed extract of G. kola at the doses of 25, 50 and 100 mg/kg body weight on sexual behaviour of male rats. Male rats weighing 215.00 ± 18.58 g were randomized completely into four groups (A-D) of six animals each. Animals in group A received, orally, 0.5 ml of distilled water only while those in groups B, C and D received same volume containing 25, 50 and 100 mg/kg body weight of the seed extract respectively. Frequencies of mount (MF), intromission (IF), genital toilet (GTF) and ejaculation (EF) as well as latencies of mount (ML), intromission (IL) and ejaculation (EL) were evaluated following the pairing of male rats (1:1) with non-oestrous female rats. The parameters were monitored for the first (15-30 min), second (75-90 min) and third (180195 min) observatory periods. The levels of testosterone, luteinizing (LH) and follicle stimulating hormones (FSH) were also determined. Phytochemical screening of the extract revealed the presence of saponins (2.78%), cardiac glycosides (0.26%), cardenolides and dienolides (0.24%), flavonoids (1.28%) and steroids (1.14%). The 25 and 100 mg/kg body weight increased (P<0.05) the MF whereas the ML was decreased by all the doses of the extract. MF and ML were not altered during the second observatory period whereas the 50 mg/kg body weight increased these parameters during the third observatory period. Other sexual behaviour parameters as well as serum testosterone, FSH and LH were not significantly altered throughout the observatory periods. Overall, the results revealed that G. kola seeds did not have sex enhancing potential as claimed. Therefore, the acclaimed pro sexual effect of Garcinia kola seeds is scientifically untrue. This study has refuted the claim that one of the rationales for consuming the seeds by the aged population of Nigeria is to enhance sexual invigoration in males.

The role of adjuvant chemotherapy in colon cancer.

Surgical resection of the primary and regional lymph nodes is still, at this time, the standard treatment of colon cancer. However, the risk of recurrence is still high in many patients. Efforts of the past decades have proved the role of systemic chemotherapy in the adjuvant setting in improving the curative rates. The combination of 5-fluorouracil (5-FU)and leucovorin (LV) remains the cornestorne of colon cancer chemotherapy worldwide. The addition of Oxaliplatin to infusional 5FU/LV has been shown to prolong significantly disease-free survival and capecitabine may be considered as an alternative to 5-FU/LV in the adjuvant therapy of stage III colon cancer. Novel molecular and biological-oriented agents are being studied, with promising date.

Percutaneous gastrostomy in patients with complete obstruction of the upper digestive tract.

Gastrostomy for nutritional support can be performed radiologically when endoscopic technique is not possible. In patients with complete obstruction of the upper digestive tract, the radiological technique in its conventional method may not be possible, as insertion of naso-gastric tube for gastric insufflation is not always successful. We reviewed our experience of gastrostomy insertion in nine such patients after failure of the conventional method. In seven of the nine patients, initial gastric puncture was achieved with a 22G needle under direct ultrasound visualisation. In the remaining two patients, initial puncture was made into locules of gas in the stomach with fluoroscopy. The stomach was then distended with air and a gastrostomy tube inserted by conventional technique. We conclude that percutaneous gastrostomy can be undertaken safely even in the presence of complete obstruction of the upper digestive tract and recommend this technique in this selective group of patients.

Persistent epistaxis: what is the best practice?

Epistaxis is the commonest otolaryngological emergency, which is often managed by a nasal pack. A significant number of cases fail to respond to nasal packing and various surgical measures are available to control the nosebleed in these cases. However evidence is sparse regarding the best available surgical option for the management of persistent epistaxis. We designed a retrospective cohort study comparing endoscopic ligation of sphenopalatine artery (ELSA) and all other surgical options (non-ELSA) in the management of persistent epistaxis. All consecutive cases of persistent epistaxis between 1997-2004 (Feb) requiring operative intervention were included in the study and divided in two groups according to the surgical intervention. Postoperative epistaxis was excluded. Non-ELSA group consisted of various procedures including nasal cautery and packing, submucous resection, anterior ethmoid artery ligation, external carotid artery ligation, internal maxillary artery ligation. Both groups were matched for age, sex, risk factors, other medical conditions and medications. The main outcome measures evaluated were immediate success in arresting the bleeding and the mean hospital stay. Recurrence and patient acceptability of the procedure were the secondary variables investigated. We found that ELSA proved to be the best practice to manage persistent epistaxis on all measures of immediate success rate, shorter hospital stay, recurrence rate, and patient satisfaction.

Health-related anxiety and the effect of open-access endoscopy in US patients with dyspepsia.

BACKGROUND: The role of endoscopy in dyspepsia is the subject of debate. The detection of lesions is infrequent, but patients may benefit from the knowledge that the examination is normal. We sought to determine the prevalence of health-related anxiety in dyspeptic patients referred for open-access endoscopy and to investigate the effect of endoscopy on health-related anxiety. METHODS: Consecutive patients referred for open-access endoscopy from primary care were studied using a validated questionnaire for health-related anxiety before and after endoscopy, at 1 month and 6 months. Symptoms were assessed using a validated questionnaire at 1 and 6 months. RESULTS: One hundred and nine patients were studied (69 women and 40 men; mean age, 49 +/- 15 years). Thirty-six of the 109 patients (33%) had high anxiety scores at baseline (mean score, 41 +/- 1), which decreased after endoscopy to 35 +/- 1 (P < 0.05). The changes persisted at 1 month (33 +/- 1) and 6 months (33 +/- 1). Endoscopic findings were as follows: normal examination, 120; erosive oesophagitis, 11 (Grade A); erosive duodenitis (all Helicobacter pylori-negative), 6. Scales for preoccupation with health and fear of illness and death showed significant improvement after endoscopy, and the effects were preserved for 6 months. Anxiety scores in our population were substantially higher than in a corresponding UK population. CONCLUSIONS: Health-related anxiety is common in dyspeptic patients referred for endoscopy. Endoscopy decreases the preoccupation with health and fear of illness and death in patients with severe anxiety, and the effects persist for 6 months.

A multinational study to measure the value that patients with cancer place on improved emesis control following cisplatin chemotherapy.

BACKGROUND: The neurokinin-1 (NK1) receptor antagonists are a new class of agents designed to reduce the risk of emesis following chemotherapy, particularly with cisplatin. Early data from double-blind randomised trials suggest that an orally administered NK1 antagonist can reduce the absolute risk of acute and delayed emesis following cisplatin by 20 and 30%, respectively. OBJECTIVE: To measure the value that patients with cancer place on improved emesis control and quality of life. DESIGN: Willingness-to-pay analysis. SETTING: Five study sites in Canada, Italy, Spain and Greece. PATIENTS AND PARTICIPANTS: 245 patients with cancer either receiving chemotherapy with cisplatin or who had received cisplatin-based chemotherapy within the previous 6 months. METHODS: After background information had been presented, patients were asked to define the maximum that they would pay per day for a drug that reduced their risk of acute and delayed (days 2 to 5) emesis by 20 and 30%, respectively. Costs were converted to US dollars ($US) using year 2000 exchange rates. RESULTS: For a 20% improvement in acute emesis, Canadian, Italian and Spanish patients with cancer were willing to pay $US46, $US34 and $US63 per day, respectively, compared with $US8 for patients from Greece (p < 0.001). For a 30% improvement in delayed emesis, Canadian, Italian and Spanish patients with cancer were also willing to pay more than their Greek counterparts (SUS41, $US31, $US50 and $US9 daily for 4 days, respectively; p < 0.001). These significant differences in patient value between countries remained, even after adjusting for socioeconomic variables and previous history of emesis. CONCLUSIONS: There are substantial cultural differences in how patients with cancer value benefit and improved quality of life. Since the majority of the world's population resides outside North America and Western Europe, there may be a need to re-evaluate perceived levels of patient benefit and measures of quality of life.

Gemcitabine plus vinorelbine in elderly or unfit patients with non-small cell lung cancer.

Cisplatin-based combinations are efficacious in increasing the overall survival of patients with non-small cell lung cancer (NSCLC), but their toxicity makes them unsuitable for elderly and unfit patients. The primary objective of this non-randomized phase II study was to evaluate the feasibility and activity of the gemcitabine plus vinorelbine combination in previously untreated elderly and/or unfit patients with measurable stage III or IV NSCLC. Forty-three patients aged >/= 65 years or with contraindications against cisplatin treatment (36 males and seven females: median age 66 years; range 48-75: PS 0 = 11, PS 1 = 19, PS 2 = 13) received intravenous (i.v.) gemcitabine 1000 mg m(-2), followed by vinorelbine 25 mg m(-2)i.v. on day 1 and 8 every 21 days. Fifteen patients (34.9%) achieved partial remission (confidence interval: 27. 6-42.2%) for a median duration of 6 months; the median survival of these patients has not yet been reached. A further 15 had stable disease for a median of 4 months and a median survival of 7 months. The 10 patients (23.2%) who experienced disease progression had a median survival of 4 months. Three patients are not evaluable. The 1-year actuarial survival rate is 31.1%. The treatment was well tolerated: only 35% of the patients had grade 3 or 4 granulocytopenia on day 14, none experienced episodes of neutropenic fever, and there was no evidence of severe haematological toxicity upon recycling. Only 9% of the patients suffered from gastrointestinal toxicity (grade 3); increased but reversible transaminase levels were observed in 11.6%. In conclusion, the results of this phase II study show that the combination of gemcitabine and vinorelbine is active and well tolerated in NSCLC, and thus encourage its use in elderly or unfit patients.

Non-invasive haemodynamic effects of two nasal positive pressure ventilation modalities in stable chronic obstructive lung disease patients.

The aim of this study was to compare the haemodynamic effects of a 45-min session of two modalities of non-invasive positive pressure ventilation (nPPV), by means of cardiac echo-Doppler and right heart catheterization, in chronic obstructive lung disease (COPD) patients with chronic respiratory insufficiency. Fourteen patients with stable COPD (11 males, mean age 62.9 +/- 9.8 years) underwent right heart catheterization using a floating Grandjean catheter and simultaneous echo-Doppler measurements before and during two randomly applied 45-min ventilatory sessions, consisting of nasal intermittent positive pressure ventilation in assist/control mode (nIPPV) and nasal pressure support ventilation (nPSV). Blood gases improved significantly during both modalities of ventilation. A significant increase during ventilatory sessions was found in invasive pulmonary right atrial pressure and cardiac output. A statistically significant decrease was found in the flow velocity peak of the superior vena cava and hepatic vein, and in systodiastolic flow velocity integral of the superior vena cava and hepatic vein. The inferior vena cava collapsibility index also decreased significantly during both ventilations. Right atrium diameter and area significantly decreased while right ventricular diameter significantly increased. The echo-Doppler cardiac output decreased significantly while systolic pulmonary artery pressure increased. A short session of both nIPPV and nPSV even without PEEP can induce significant haemodynamic changes in patients with stable COPD. Two-dimensional Doppler echocardiography is a non-invasive device with sufficient reliability to monitor the haemodynamic effects of nPPV. Further studies are needed to assess the effects of nPPV on vascular peripheral flows.

Methacholine inhaled challenge: study of correlation among different indices expressing the result.

We tested measures of specific airway conductance (sGaw) and forced expiratory volume in one second (FEV1) versus transcutaneous oxygen tension (Ptc,O2) during inhaled methacholine bronchial challenge in 60 out-patients (38 males 22 females, mean age 33 +/- 13 yrs). The provocative doses of methacholine needed to produce a 35% decrease of sGaw (PD35,sGaw), a 20% fall in FEV1 (PD20,FEV1) and a 20% decrease in Ptc,O2 (PD20,O2) were simultaneously derived from the dose-response curves. Two groups were identified according to the PD20,FEV1 result ("responders" with a PD20,FEV1 < 2,000 micrograms methacholine and "nonresponders" with PD20,FEV1 > 2,000 micrograms methacholine). All three indices derived from the dose-response curves differed significantly between the groups (p < 0.00005). The relationship analysis showed a significantly better value for PD20,O2 versus PD35,sGaw (r = 0.98) than versus PD20, FEV1 (r = 0.62). We observed similar baseline levels and variations in arterial oxygen tension (Pa,O2) and Ptc,O2 during methacholine challenge (-25 and -27%, respectively) in 14 randomly studied responders. Thus, inhaled methacholine-induced hypoxaemia (PD20,O2) seems to reflect PD35,sGaw better than changes in FEV1. Our investigation supports the hypothesis that PD20,O2 could be useful in interpreting the methacholine inhaled challenge. It could be of help in clarifying the pathophysiological meaning of the concurrent hypoxaemia during this challenge, which should be further elucidated.

Echo-Doppler evaluation of left ventricular impairment in chronic cor pulmonale.

The effects of acute right ventricular (RV) pressure and volume overloads on left ventricular (LV) filling are well known, while the significance of chronic RV pressure overload on LV function has been less studied. To evaluate the LV impairment, 30 patients with chronic cor pulmonale and pulmonary arterial hypertension secondary to chronic obstructive lung diseases (COLDs) were studied. All patients underwent respiratory tests and arterial blood gas assessment. An echo-Doppler examination was made to measure LV ejection fraction (EF), RV and LV end-diastolic and end-systolic diameters and areas, RV/LV area indexes, LV diastolic and systolic eccentricity indexes, mitral and tricuspid flow patterns, and mitral flow velocity in late and early diastole (A/E) indexes. A right heart catheterization was carried out to determine the resting mean pulmonary arterial pressure (mPAP). The data showed a marked enlargement of RV, compressing the left through a leftward shift of interventricular septum. A linear regression analysis detected a significant correlation between mPAP and the following parameters: RV/LV diastolic and systolic area indexes (r=0.75, p<0.0001; r=0.84, p<0.000, respectively), mitral A/E index (r=0.61, p<0.0005), and LV diastolic and systolic eccentricity indexes (r=0.93, p<0.0001; and r=0.83, p<0.0001). No correlations were found between echo-Doppler data and functional respiratory parameters. From these results, we conclude that chronic RV pressure overload induces LV filling impairment despite a normal systolic phase, due to septal leftward shift. In fact, chronic RV pressure overload distorts early diastolic LV geometry delaying LV filling phase, and the functional diastolic impairment of the LV is closely correlated to pulmonary hypertension levels.

Does the supine position worsen respiratory function in elderly subjects?

The aim of our study was to test whether the supine position or the sitting position worsens static, forced expiratory flows and measurements of lung mechanics in a group of aged subjects living in a nursing home who were clinically stable and without clinical evidence of cardiorespiratory diseases. Seventeen subjects (mean age 80 +/- 7 years; 16 f) were studied under baseline conditions. Spirometric, breathing pattern and mechanics data by means of an esophageal balloon were measured in sitting and supine positions. Analysis of sitting results showed aged subjects to have a slight flow limitation in peripheral airways, an increase in expiratory airways resistance and mild hyperinflation index (PEEPi = 2.2 +/- 1.9 cm H2O). Pressure time index did not reach the fatigue level in hardly any patient. Maximal inspiratory pressure values (42 +/- 15 cm H2O) were reduced by about 50% in comparison with our normal laboratory standards. Arterial blood gas analysis revealed no pathological data in any subject. When supine, subjects revealed a significant decrease in forced expiratory volume at the first second (p < 0.005), in forced vital capacity (p < 0.01) and in peak expiratory flow (p < 0.05). Moreover, mechanics and breathing pattern data showed a significant decrease in tidal volume (Vt) and dynamic lung compliance (Cld) (p < 0.05) and an increase in respiratory rate/Vt ratio (p < 0.05). Our data confirm the results of previous reports about Cld decrease in supine posture in young normal people. Although our aged subjects showed a significant decrease in forced expiratory volumes and Vt when the supine position was adopted, static mechanics data did not appear modified by the gravitational effect of this posture.