GRAVITY FIELD: THEORETICAL AND EXPERIMENTAL CONTRIBUTION TO STUDY WEIGHING PENDULUM PERIOD

We present in this article a theoretical study and experimental variations of the period of a pendulum consisting of a heavy rigid rod on which we can translate a mass . The study was conducted at the National Advanced School of Engineering, University of Yaounde I. The product was manufactured in a metal carpenter room for a relatively modest cost. The study is carried out in dependence on the position of the mass relative to the axis of rotation. We show that the model developed in the context of solid mechanics fits successfully experience while one developed in the context of the approximation of the mechanical point has only limited validity range, the asymptotic behavior for which the mass is from the axis of rotation. We define explicitly the field and compare with experiment.&nbsp

Effects of Gladiolus dalenii on the Stress-Induced Behavioral, Neurochemical, and Reproductive Changes in Rats

Gladiolus dalenii is a plant commonly used in many regions of Cameroon as a cure for various diseases like headaches, epilepsy, schizophrenia, and mood disorders. Recent studies have revealed that the aqueous extract of G. dalenii (AEGD) exhibited antidepressant-like properties in rats. Therefore, we hypothesized that the AEGD could protect from the stress-induced behavioral, neurochemical, and reproductive changes in rats. The objective of the present study was to elucidate the effect of the AEGD on behavioral, neurochemical, and reproductive characteristics, using female rats subjected to chronic immobilization stress. The chronic immobilization stress (3 h per day for 28 days) was applied to induce female reproductive and behavioral impairments in rats. The immobilization stress was provoked in rats by putting them separately inside cylindrical restrainers with ventilated doors at ambient temperature. The plant extract was given to rats orally everyday during 28 days, 5 min before induction of stress. On a daily basis, a vaginal smear was made to assess the duration of the different phases of the estrous cycle and at the end of the 28 days of chronic immobilization stress, the rat’s behavior was assessed in the elevated plus maze. They were sacrificed by cervical disruption. The organs were weighed, the ovary histology done, and the biochemical parameters assessed. The findings of this research revealed that G. dalenii increased the entries and the time of open arm exploration in the elevated plus maze. Evaluation of the biochemical parameters levels indicated that there was a significant reduction in the corticosterone, progesterone, and prolactin levels in the G. dalenii aqueous extract treated rats compared to stressed rats whereas the levels of serotonin, triglycerides, adrenaline, cholesterol, glucose estradiol, follicle stimulating hormone and luteinizing hormone were significantly increased in the stressed rats treated with, G. dalenii, diazepam and in co-administration of the plant extract and diazepam treated rats. Moreover stressed rats showed significant changes in estrous cycle phases compared to vehicle control and these changes of the estrous cycle were less in the rats treated with G. dalenii compared to the negative control rats. G. dalenii extract showed antagonizing effects on the stress-induced reproductive, behavioral, and neurochemical changes. These effects could be related to the bioactive molecules and secondary metabolites like alkaloids and flavonoids in the plant

ANTIDEPRESSANT PROPERTIES OF AQUEOUS MACERATE FROM GLADIOLUS DALENII CORMS

Background: Gladiolus dalenii Van Geel (Iridaceae) has been used for the treatment of depression and psychotic disorders in African traditional medicine. The aim of this study was to assess the effect of the aqueous extract from the corm of Gladiolus dalenii and its possible mechanisms of action. Materials and Methods: We assessed the antidepressant properties of G. dalenii corm aqueous extract in mice, using the open field, forced swimming, and tail suspension tests. Spontaneous locomotor activity of mice given various doses of G. dalenii extract (per os) was determined in the open field, whereas immobility was evaluated in the other two tests. Results: Extract maximal effect was observed at 15 mg/kg, as mice displayed a marked reduction in immobility time in both the forced swimming test (80%) and the tail suspension test (66%). In further studies aimed at investigating the mechanism of action of G. dalenii extract, the latter significantly antagonized the effect of N-methyl-D- aspartate (NMDA, 75 mg/kg) at both the doses 15 mg/kg (

Anxiolytic - like properties of Hallea ciliata in mice

Background: The aim of the present study was to evaluate the anxiolytic properties of the decoction of stem bark of Hallea ciliate in mice. The decoction of Hallea ciliata is used in traditional medicine in Cameroon to treat diseases like anxiety disorders, fever, infantile convulsions and malaria.Materials and Methods: Stress induced hyperthermia, elevated plus maze, open field and hole-board tests were used. Four different doses of the decoction were administered to mice and their effects were compared to the effects of diazepam and vehicle. Phytochemical characterization of the decoction revealed the presence of alkaloids, flavonoids, tannins and saponins.Results: Administration of Hallea ciliata resulted in a significant decrease of stress induced hyperthermia in mice at the doses of 29.5, 59 and 118 mg/kg. In the elevated plus maze test, Hallea ciliata increased the number of entries and the percentages of entries and time into the open arms, and reduced the number of entries and the percentages of entries and time into the closed arms. In the  hole-board test, Hallea ciliata increased the number of both head-dipping and crossing and decreased the latency to the first head-dips and rearing. The decoction of Hallea ciliata and diazepam increased locomotion in the open field test.Conclusion: The number of rearing and the mass of fecal boli produced were decreased in mice treated with decoction and diazepam. In conclusion, the results indicated that decoction of Hallea ciliata has anxiolytic-like properties in mice and could potentially be used for anxiety treatment.Key words: anxiety, herbs, pharmacology, diazepa

SEDATIVE AND ANTICONVULSANT PROPERTIES OF PASSIFLORA EDULIS DRIED LEAVES DECOCTION IN MICE

Passiflora edulis Sims is native from Tropical area of South America. It is used in traditional medicine in the treatment of some diseases related to the nervous system and others. The extract of Passiflora edulis possesses sedative activity in mice. It significantly increased the total sleep time induced by diazepam (50 mg/kg i.p.). The total sleep time increased from 31 + 11 min in the control group to 77.6 + 15 and 78.3 + 16 min in the groups treated with extract at the doses of 132.5 and 1325 mg/kg respectively. This extract showed also anticonvulsant activity in mice. It protected mice against strychnine -induced seizures and antagonized N-methyl-D-aspartate- induced turning behavior in mice. The ED50 for the protection against seizures -induced by strychnine was 320 mg/kg intraperitoneally (i.p.). For N-methyl-D-aspartate -induced turning behavior, the ED50 was 300 mg/kg i.p. Passiflora edulis extract had less effect against pentylene tetrazol- induced seizures. The potentiation of diazepam-induced sleep, the antagonism of chemical -induced seizures and turning behavior suggest that Passiflora edulis extract possess sedative and anticonvulsant properties in animals

ANXIOLYTIC - LIKE PROPERTIES OF HALLEA CILIATA IN MICE

Background: The aim of the present study was to evaluate the anxiolytic properties of the decoction of stem bark of Hallea ciliata in mice. The decoction of Hallea ciliata is used in traditional medicine in Cameroon to treat diseases like anxiety disorders, fever, infantile convulsions and malaria. Materials and Methods: Stress induced hyperthermia, elevated plus maze, open field and hole-board tests were used. Four different doses of the decoction were administered to mice and their effects were compared to the effects of diazepam and vehicle. Phytochemical characterization of the decoction revealed the presence of alkaloids, flavonoids, tannins and saponins. Results: Administration of Hallea ciliata resulted in a significant decrease of stress induced hyperthermia in mice at the doses of 29.5, 59 and 118 mg/kg. In the elevated plus maze test, Hallea ciliata increased the number of entries and the percentages of entries and time into the open arms, and reduced the number of entries and the percentages of entries and time into the closed arms. In the hole-board test, Hallea ciliata increased the number of both head-dipping and crossing and decreased the latency to the first headdips and rearing. The decoction of Hallea ciliata and diazepam increased locomotion in the open field test. Conclusion: The number of rearing and the mass of fecal boli produced were decreased in mice treated with decoction and diazepam. In conclusion, the results indicated that decoction of Hallea ciliata has anxiolytic-like properties in mice and could potentially be used for anxiety treatment

Anxiolytic and Antiepileptic Properties of the Aqueous Extract of Cissus quadrangularis (Vitaceae) in Mice Pilocarpine Model of Epilepsy

Cissus quadrangularis (C. quadrangularis) is a plant of the Vitaceae family known for its anticonvulsant effects in traditional medicine. The objective of this study was to elucidate the anxiolytic and antiepileptic effects of aqueous extract of C. quadrangularis. The mice were divided into different groups and treated for seven consecutive days as follows: a negative control group that received distilled water, po, four test groups that received four doses of the plant (37.22, 93.05, 186.11, and 372.21 mg/kg, po), and a positive control group that received sodium valproate (300 mg/kg, ip). One hour after the first treatment (first day), epilepsy was induced by intraperitoneal administration of a single dose of pilocarpine (360 mg/kg). On the seventh day, the anxiolytic effects of the extract were evaluated in the epileptic mice using the elevated plus maze (EPM) and open field (OP) paradigms. Antioxidant activities and the involvement of gabaergic neurotransmission were determined by measuring the levels of malondialdehyde, reduced glutathione (GSH), GABA, and GABA-transaminase (GABA-T) in the hippocampus of sacrificed epileptic mice. The results show that the extract of C. quadrangularis significantly and dose-dependently increased the latency to clonic and generalized tonic–clonic seizures and decreased the number and duration of seizures. In the EPM, the extract of C. quadrangularis significantly increased the number of entries and the time spent into the open arms and reduced the number of entries and the time spent into the closed arms as well as the number of rearing. The extract of C. quadrangularis also increased the number of crossing, and the time spent in the center of the OP. The level of MDA and the activity of GABA-T were significantly decreased by the extract of C. quadrangularis while reduced GSH and GABA levels were increased. The results suggest that the anticonvulsant activities of C. quadrangularis are accompanied by its anxiolytics effects. These effects may be supported by its antioxidant properties and mediated at least in part by the GABA neurotransmission

EVALUATION OF THE SEDATIVE AND ANTICONVULSANT PROPERTIES OF THREE CAMEROONIAN PLANTS

Millettia thonningii, Ocinum sanctum and Securitaca longepedunculaca are used in traditional medicine in Cameroon to treat epilepsy, insomnia and headaches. Animal models of epilepsy (maximal electroshock (MES), n-methyl-d-aspartate (NMDA), pentylenetetrazol (PTZ), isonicotinic hydrazide acid (INH), picrotoxine (PIC) and strychnine (STR)-induced convulsions or turning behavior were used to evaluate anticonvulsant activity while diazepam-induced sleep test was used to evaluate sedative activity of the plants. Four doses of extracts were used for each plant (100, 200, 500 and 1000 mg/kg). At a dose of 1000 mg/kg, Millettia thonningii protected 60 and 90% of mice against MES and PTZ-induced convulsions, respectively. At the same dose, Millettia thonningii also protected 80% of mice against NMDA-induced turning behavior. At a dose of 1000 mg/kg, Ocinum sanctum provided complete protection against MES, PIC and STR- induced convulsions and 83.3% of protection in PTZ test. Securitaca longepedunculata completely protected (100%) mice in PIC test at a dose of 200 mg/kg, in MES test at a dose of 500 mg/kg and in PTZ test at a dose of 1000 mg/kg. 66.7% of mice were protected against STR-induced convulsions. All the three plants showed also sedative properties for they increased significantly and in a dose dependent manner the total sleep time induced by diazepam. The total sleep time of the control groups was multiplied by a factor of 3 at least by each extract. The presence of sedative and anticonvulsant activity in the three plants could explain their use in traditional medicine in the treatment of epilepsy and insomnia in Cameroon

ANTIOXIDANT PROPERTIES OF DICHROCEPHALA INTEGRIFOLIA (ASTERACEAE) IN A MOUSE MODEL OF MONOSODIUM GLUTAMATE-INDUCED NEUROTOXICITY

Background: In Africa, neurodegenerative diseases in the elderly have become a major health concern due to the increase in live expectancy. Glutamate mediated neurotoxicity is involved in neurodegenerative diseases such as Ischemia, Epilepsy, Alzheimer’s and Parkinson diseases. Plants with antioxidant properties are reported to protect vital organs against glutamate toxicity. This study aims to assess the effect of Dichrocephala integrifolia against monosodium glutamatemediated neurotoxicity and oxidative stress. Methodology: The decoction prepared from the leaves of Dichrocephala integrifolia was evaluated against monosodium glutamate-induced neurotoxicity in mice. The animals were grouped in seven groups of 6 animals each. The animals received daily; distilled water (p.o) for the distilled water and the negative control groups, one of the four doses of the decoction of the plant (35, 87.5, 175 or 350 mg/kg p.o) for the tests groups and memantine (20 mg/kg p.o) for the positive control group. Monosodium glutamate (2.5 g/kg ip) was injected daily to animals except those of the normal control group all the seven days of the experimentation. Animals were observed for aggressiveness, locomotor and forepaws muscle grip activities 30 min after monosodium injections. Brain reduced glutathione and malondialdehyde levels were also assessed following the behavioral tests on day 8. Results: The decoction of Dichrocephala integrifolia at the doses of 87.5 and 175 mg/kg significantly (

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat