ABSTRACT
Objective: This article compares the study design and statistical methods used in 2005, 2010 and 2015 of Pakistan Journal of Medical Sciences [PJMS]
Methods: Only original articles of PJMS were considered for the analysis. The articles were carefully reviewed for statistical methods and designs, and then recorded accordingly. The frequency of each statistical method and research design was estimated and compared with previous years
Results: A total of 429 articles were evaluated [n=74 in 2005, n=179 in 2010, n=176 in 2015] in which 171 [40%] were cross-sectional and 116 [27%] were prospective study designs. A verity of statistical methods were found in the analysis. The most frequent methods include: descriptive statistics [n=315, 73.4%], chi-square/Fisher's exact tests [n=205, 47.8%] and student t-test [n=186, 43.4%]. There was a significant increase in the use of statistical methods over time period: t-test, chi-square/Fisher's exact test, logistic regression, epidemiological statistics, and non-parametric tests
Conclusion: This study shows that a diverse variety of statistical methods have been used in the research articles of PJMS and frequency improved from 2005 to 2015. However, descriptive statistics was the most frequent method of statistical analysis in the published articles while cross-sectional study design was common study design
ABSTRACT
Since Achillea wilhelmsii is used as antispasmodic in traditional medicine, we conducted our current work to investigate its rationale on scientific grounds. Acute toxicity studies of crude methanol extract of Achillea wilhelmsii [Aw. CMeOH] is also performed. Effect of Aw. CMeOH and its fractions were tested on isolated sections of rabbits' jejunum at test concentrations 0.01, 0.03, 1.0, 3.0, 5.0 and 10mg/ml. The test extracts, in similar concentrations, were also tested on KCl-induced contractions. Calcium chloride curves were constructed for those fractions which relaxed KCl induced contractions in the absence and presence of the test samples to investigate its possible mode of action through calcium channels. Aw. CMeOH tested positive for flavonoids, saponins, tannins, glycosides, terpenoids, sterols, phenols, carbohydrates and proteins. LD[50] for acute toxicity studies is 2707 +/- 12.6 mg/kg. Mean EC[50] values for Aw. CMeOH on spontaneous and KCl-induced contractions are 3.41 +/- 0.18 [2.56-3.8, n=6] and 0.68 +/- 0.05 [0.6-0.85, n=6] mg/ml, respectively. Respective EC[50] values for n-hexane fraction on spontaneous and KCl-induced contractions are 3.06 +/- 0.08 [2.8-3.3, n=6] and 1.68 +/- 0.8 [1.4-1.9, n=6] mg/ml, respectively. Corresponding EC[50] [mg/ml] values for chloroformic, ethylacetate and aqueous fractions of Achillea wilhelmsii on spontaneous rabbits' jejunum preparations are 4.8 +/- 0.2 [4.41-5.63, n=6], 5.07 +/- 0.15 [4.7-5.58, n=6] and 5.2 +/- 0.13 [4.91-5.64, n=4], respectively. Constructing calcium chloride curves, in the presence of 0.1 mg/ml of Aw. CMeOH, mean EC[50] value [log molar [Ca[++]]] is-1.98 +/- 0.03 [-1.89-2.05, n=6] vs. control EC50 [log molar [Ca[++]]]-2.41 +/- 0.02 [-2.32-2.44, n=6]. Mean EC50 value [log molar [Ca[++]]] for 0.3 mg/ml n-hexane fraction is-1.76 +/- 0.05 [-1.70 -1.93, n=6] vs. control EC50 [log molar [Ca[++]]] value-2.18 +/- 0.07 [-2.0-2.46, n=6]. While in the presence of chloroformic fraction [3 mg/ml], mean EC50 [log molar [Ca[++]]] value is -2.4 +/- 0.1 [-2.78 - 2.9, n=6] vs. control EC50 [log molar [Ca[++]]] value-2.70 +/- 0.05 [-2.5-2.8, n=6]. Mean EC50 value [log molar [Ca[++]]] for ethyl acetate fraction [1 mg/ml] is-1.94 +/- 0.07 [-1.75-2.05, n=6] vs. control EC50 [log molar [Ca[++]]] value-2.69 +/- 0.04 [-2.57-2.79, n=6]. Mean EC50 [log molar [Ca[++]]] value for residual aqueous fraction [3 mg/ml] is-1.8 +/- 0.3 [-1.71-1.84, n=6] vs. control EC50 [log molar [Ca++]] -2.6 +/- 0.04 [-2.59-2.76, n=6]. Whereas, the verapamil [0.1 micro M] EC[50] value [log molar [Ca[++]]] is-1.7 +/- 0.1 [-1.6-1.8, n=6] vs. control EC50 value [log molar [Ca[++]]]- 2.4 +/- 0.09 [-2.3-2.47, n=6]. The present research work confirms that the intestinal relaxation effect of Achillea wilhelmsii is supporting its traditional use as antispasmodic. The plant species can be a source for calcium antagonist[s], which can preferably be isolated from n-hexane fraction
ABSTRACT
Methanolic extract of Onosma grifflthii and its fractions were evaluated for possible effects on rabbits' jejunum preparations. Rabbits of either sex [weight 1.5-2.0 kg] were used in experiments. Studies were carried out on rabbits' jejunum preparations. Crude methanolic extract of Onosma griffithii [Meth.OG] was tried in concentrations of 0.01, 0.03, 0.1, 0.3, 1.0, 3.0, 5.0 and 10.0 mg/ml on rabbits' jejunum preparations. Meth.OG was also tried on KCl-induced contractions to explain its possible mode of actions in the presence and absence of atropine [0.03 microM]. Fractions of Meth.OG were tried in similar manner. Calcium chloride curves were constructed for Meth.OG treated tissues that were compared with curves constructed for verapamil in same fashion. Preliminary phytochemical screening of the plant was also performed. Meth.OG increased the amplitude of spontaneous activity of rabbits' jejunum preparations at concentrations of 0.1, 0.3 and 1.0 mg/ml. However, spasmolytic effects were observed at higher concentrations 3.0, 5.0 and 10.0 mg/ml. Mean EC[50] values [mg/ml], respectively, in absence and presence of atropine were 7.5 +/- 0.25 [6.9-8.4, n=6] and 3.0 +/- 0.17 [2.3-3.5, n=6, P<0.05]. Mean EC[50] values, respectively, for effects on spontaneous and KCl-induced contractions were 7.5 +/- 0.25 [6.9-8.4, n=6] and 7.3 +/- 0.35 [6.25-8.2, n=6, p<0.05]. rc-Hexane, chloroform and ethyl acetate fractions showed their respective EC[50] values [mg/ml] 9.7 +/- 0.25 [8.6-10.2, n=6], 4.0 +/- 0.2 [3.5-4.6, n=6] and 1.07 +/- 0.093 [0.78-1.5, n=6]. EC[50] values for calcium chloride curves in presence of 0.3 mg/ml Meth.OG were - 2.27 +/- 0.038 [- 2.4 to - 2.10, n=6] vs. control - 2.78 +/- 0.04 [-2.9 to - 2.6, n=6,P<0.05] Log [Ca[++]]M. Comparing with curves of calcium chloride constructed in presence of 0.1 juM verapamil, the EC[50] [log [Ca[++]] M] values were - 1.82 +/- 0.087 [- 2.0 to - 1.65, n=6] vs. control - 2.64 +/- 0.089 [- 2.9 to - 2.4, n=6] demonstrated a right shift [p<0.05]. Meth.OG tested positive for terpenes, saponins, sterols, flavonoids and carbohydrates. We concluded that the relaxant effect of Meth.OG is exerted through blocking of calcium channels. However,
butanolic and aqueous fractions produced spasmogenic effects that require further work for isolation of pharmacologically active substances