Physical Activity and Natural Products and Minerals in the SARS-CoV-2 Pandemic: An Update

Coronavirus-disease 19 (COVID-19) has rapidly become a global public health issue, and there is a desperate need for strategies of prevention, reduction, and treatment to halt the epidemic. The coronavirus affects the immune system, and individuals with a compromised immune system, such as those with diabetes, hypertension, obesity, are more susceptible to this virus. Lifestyle-related variables such as physical activity and nutritional supplements can decrease inflammatory markers, increase anti-inflammatory and antioxidant status, and improve the immune system. Lifesty-lerelated variables play preventive roles against various infectious diseases including COVID-19. This review highlights the effects of physical activity and nutrients supplements on the immune system and their possible benefits in combating the harms caused by infection with the COVID-19 virus.

Detection of DNA by scraping the formalin-fixed paraffin-embedded tissue

BACKGROUND

Pakistan is a developing country and most of the research laboratories have limited required infrastructures for the diagnosis of cancer at molecular level. The polymerase chain reaction (PCR) on formalin-fixed paraffin-embedded tissues is becoming a popular procedure in the research centres. The study was conducted to introduce two new methods of DNA extraction for the PCR from formalin-fixed paraffin-embedded sections of surgical pathology specimens.

MATERIALS AND METHODS

Two methods of DNA detection were used. In method A the formalin-fixed tissues were grossed, proper sections were taken, processed in an automatic tissue processor, embedded in paraffin blocks, and microtomic sections were made. In method B, the procedure was the same until embedding in the paraffin blocks, after which the selected paraffin blocks were set on a black card paper (4 cm x 4 cm) and 1 mg of pure scraped tissue was obtained using a scalpel, manually without using microtone.

RESULTS

DNA was successfully extracted but point mutation of p53 gene was not seen in SCP while it was determined in 96 and 93.75 per cent cases of SCC by method A and method B respectively. There was no statistical difference in the results by both methods (P = 0.359).

CONCLUSION

Scraping of the tissue for DNA detection was a simple method and may be performed in any laboratory. The reliability, reproducibility, and quality assurance of the present results are consistent with the already established techniques of DNA extraction for PCR.

Long-term outcome and objective changes of anorectal function after biofeedback therapy for faecal incontinence

BACKGROUND

In the short-term, biofeedback therapy improves symptoms and anorectal function in patients with faecal incontinence but whether there is long-term improvement is incompletely understood.

AIM

To prospectively evaluate bowel symptoms and anorectal function, both immediately and 12 months after biofeedback therapy.

METHODS

A total of 105 consecutive patients (male/female = 12/93) with faecal incontinence, unresponsive to supervised medical treatment were enrolled in biofeedback training consisting of biweekly pelvic muscle strengthening exercises, anal squeeze and sensory-motor coordination training, and reinforcement sessions at 3, 6 and 12 months. Anorectal manometry, saline continence test, stool diaries and bowel satisfaction scores were used to assess improvement.

RESULTS

94/105 (male/female = 10/84) completed training and 11 dropped out. Sixty completed 1-year assessment. At 1-year, 63% reported no episodes of incontinence. Biofeedback decreased (P < 0.001) stool frequency and number of incontinence episodes and increased (P < 0.001) bowel satisfaction score, anal resting and squeeze pressures, squeeze duration and ability to retain saline infusion increased (P < 0.001), both immediately and at 1 year. Sensory thresholds decreased (P < 0.001).

CONCLUSIONS

Biofeedback therapy produced sustained improvement in bowel symptoms and anorectal function. Because it is safe, inexpensive compared with other surgical interventions, and effective, biofeedback should be offered to incontinent patients unresponsive to medical therapy.

The gene for cherubism maps to chromosome 4p16

Cherubism is an autosomal dominant disorder that may be related to tooth development and eruption. It is a disorder of age-related bone remodeling, mostly limited to the maxilla and the mandible, with loss of bone in the jaws and its replacement with large amounts of fibrous tissue. We have used a genomewide search with a three-generation family and have established linkage to chromosome 4p16. Three other families affected with cherubism were also genotyped and were mapped to the same locus. The combined LOD score is 4.21 at a recombination fraction of 0, and the locus spans an interval of approximately 22 cM.

Effect of acute water deprivation on renal function in rats

The effect of acute water deprivation for 96 h on renal function was studied in male Sprague-Dawley rats. The glomerular filtration rate (GFR) and the effective renal plasma flow (ERPF) were estimated using inulin and p-amino hippuric acid (PAH), respectively, as model compounds. Acute water deprivation caused a significant decrease (44 per cent) in the GFR without altering the ERPF. These results indicate that a proper dosage adjustment may have to be made in the dehydration condition, especially for drugs whose disposition is dependent on GFR.

Influence of water deprivation on the disposition of paracetamol

The effect of acute (96 h) water deprivation on the disposition of paracetamol (acetaminophen) has been examined in male Sprague-Dawley rats. Plasma and urinary concentrations of the drug and its two major metabolites, the glucuronide and sulphate, were determined by a sensitive and specific high performance liquid chromatographic assay. Following an intravenous dose of 100 mg kg-1 of paracetamol, no significant changes were found in the elimination rate constant (k), the mean residence time (MRT), total plasma clearance (Cl) and the apparent volume of distribution at steady-state (Vss). However, rats deprived of water for 96 h excreted a larger percentage of the administered dose as the glucuronide conjugate (15.3 vs 7.9%) and a smaller percentage as unchanged paracetamol (7.3 vs 20.7%) in the urine. In addition, there was a significant two-fold increase in the partial metabolic clearance to paracetamol glucuronide. Water deprivation also led to a significant reduction in the renal clearance of paracetamol accompanied by an increase in the renal clearance of the glucuronide.

Influence of short-term water deprivation on antipyrine disposition

The effects of acute (96 h) water deprivation on the disposition kinetics of antipyrine and hepatic cytochrome P-450 content were investigated in male rats. The disposition kinetics of antipyrine in rats deprived of water for 96 h was altered significantly: the total body clearance and steady-state volume of distribution decreased by 27.1 and 22.4%, respectively, as compared to control rats. There was no significant change in the disposition rate constant as a result of simultaneous changes in the volume of distribution and clearance. There was a 51.4% decrease in the hepatic cytochrome P-450 content in water-deprived rats. These results suggest that the pharmacokinetic changes observed in acute water deprivation with a model drug, antipyrine, are related to a decrease in total body water and to a reduced amount and/or activity of the hepatic microsomal oxidative enzymes.

Unbound plasma salicylate concentration in rheumatoid arthritis patients

This study was designed to investigate the relationship of free plasma salicylate to total plasma salicylate and to determine the clinical utility of monitoring the free plasma salicylate concentration. Analysis of 46 patient samples indicated a close correlation between the free and total plasma concentration and that there is no additional advantage to monitoring the free plasma salicylate concentration. Also this study re-emphasizes the unique pharmacokinetic characteristics of salicylate, whereby the amount of free plasma salicylate increases disproportionately with increased total plasma salicylate concentration.

A new metabolite of butylated hydroxyanisole in man

Butylated hydroxyanisole (I) is one of the most commonly used food antioxidants. Its use has been suggested to inhibit a variety of carcinogenic responses. The present study on the disposition kinetics of (I) in man indicates that contrary to previous reports, (I) undergoes significant O-demethylation in the body yielding a tert-butyl hydroquinone. It is suggested that this metabolic conversion may be responsible for some of the in vivo activities of (I) against chemical carcinogens.

Effect of water deprivation on aspirin disposition kinetics

Temporary water deprivation results in serious stress causing significant physiological, hormonal, and enzymatic changes in the body which can affect the disposition kinetics, toxicity, and activity of drugs. This study attempts to recognize the effect of water deprivation on drug disposition kinetics using aspirin. No significant effects were noted following 36-hr water deprivation in rats on the metabolism of aspirin; there was also no effect of heparinization on aspirin disposition kinetics. The disposition of salicylic acid, however, was altered significantly, with the half-life increased by approximately 72% concomitant with decreased total body clearance. The effect of two dose levels, 5 and 10 mg/kg, was also studied to elucidate nonlinearity in the disposition kinetic model. Almost complete urinary recovery of aspirin was obtained in the intact form or as metabolites. At the 10-mg/kg dose, the fraction of salicyluric acid excreted decreased significantly compared with the 5-mg/kg dose. However, the effect of water deprivation was uniform at the two dose levels without any effect on the excretion of salicyluric acid. It is suggested that, in view of the significant changes in the disposition characteristics of salicylates with water deprivation, due care must be exercised in adjusting doses giving proper consideration to body hydration levels.

High-performance liquid chromatographic determination of aspirin and its metabolites in plasma and urine

A simple quantitative method for the rapid determination of aspirin and its metabolites, salicylic acid, salicyluric acid, and gentisic acid, in plasma and urine using o-toluic and o-anisic acids, respectively, as internal standards was developed. Plasma proteins were precipitated by the addition of acetonitrile and, after centrifugation, the supernatant fluid was injected directly onto a reverse-phase column. The mobile phase consisted of an isocratic mixture of water, methanol, and glacial acetic acid (64:25:1, v/v/v) and the separated components were detected at 238 nm using a UV detector. Concentrations greater than or equal to 0.5 microgram/ml could be quantitated for aspirin or its metabolites in plasma. The peak heights and peak height ratios to the internal standard, o-toluic acid, were linear for the concentration range of 0.5-200 micrograms/ml. The aspirin metabolites in urine were isolated by extracting the acidified urine with either and then reextracting the material into an aqueous buffer solution at pH 7.0. Twenty microliters of the buffer extract was directly injected onto the column. The separated components were detected and quantitated at 305 nm. Concentrations greater than or equal to 5 micrograms/ml of salicyluric acid, salicylic acid, and gentisic acid could be determined accurately. The peak heights and peak height ratios to the internal standard, o-anisic acid, were found to be linear for the concentration range of 5-200 micrograms/ml in urine.

Simple reliable method for chronic cannulation of the jugular vein for pharmacokinetic studies in rats

A simple method for the preparation and implantation of silicone cannulas into the rat jugular vein is described. The implanted cannula can be used to administer drugs and collect blood samples at intervals of less than or equal to 1 min without causing stress to the animal. If necessary, the animals can be exsanuinated within a few minutes using this cannula. With proper maintenance, the cannula is patent for weeks and could be used for repeated and crossover studies.

Stability of aspirin in different media

Aspirin rapidly hydrolyzes in various aqueous, organic, and biological media. The purpose of this investigation was to study the decomposition of aspirin in the media that comes in contact with it during analysis in biological fluids for pharmacokinetic studies. These media included water, water-polyethylene glycol 400, water-methanol-acetic acid, phosphate buffer, freshly drawn blood and plasma from control rats and rats deprived of water for 36 hr, and blood precipitated with acetonitrile. Studies were also conducted to determine the decomposition as a function of temperature and pH. Of the various solvent systems studied, aspirin was found most stable in water-polyethylene glycol (4:1, v/v),which provides an excellent medium for preparation of intravenous dosage forms. Phosphate buffer showed significant catalysis of aspirin hydrolysis. A more than fivefold increase in the hydrolysis of aspirin was noted when the temperature was raised to 37 degrees from 22.5 degrees. The hydrolysis of aspirin in rat blood was 13 times faster than that in plasma, with an average half-life in blood of approximately 13 min. This creates significant problems in aspirin disposition kinetic studies. Mixing the blood sample immediately after collection with twice the volume of acetonitrile and thn en centrifuging gives a plasma-acetonitrile mixture in which no lysis of blood cells is observed.

Absorption and disposition characteristics of nitrofurantoin in dogs

This study reports the disposition kinetic properties of nitrofurantoin in dogs following single intravenous and oral administration of various formulations of nitrofurantoin. Also reported here is the effect of delaying gastric emptying by food and atropine on the absorption characteristics of nitrofurantoin. The drug absorption parameters calculated using a deconvolution computer program indicate that the rate and extent of enterohepatic recycling affects the elimination and absorption rate constants and thus confound the bioavailability calculations of nitrofurantoin, heretofore unrecognized in the literature. The plasma half-life following intravenous administration was 31 min (monoexponential equation) with little effect of enterohepatic recycling noted. Following oral administration, a biexponential equation with lag-time was used to fit the blood levels. The absorption half-lives were higher when nitrofurantoin was administered as a solid dosage form compared to a solution. The absorption half-lives following tablet administration ranged from 30 to 72 min and were not affected by food or atropine. The elimination half-lives following oral administration ranged from 19 to 87 min with significantly prolonged elimination when solid dosage forms were administered compared to solution. The extent of absorption ranged from 38 to 120 per cent. A direct correlation between the absorption and elimination half-life was established, indicating that increased biliary recycling direct affects the apparent disposition half-life. The three brands of nitrofurantoin tested for bioavailability showed that the use of blood levels without appropriate corrections for biliary recycling are not suitable for bioavailability testing of nitrofurantoin. The use of urinary excretion data in evaluating nitrofurantoin bioavailability is also questioned in the study.

Comparative pharmacokinetics of butylated hydroxyanisole and butylated hydroxytoluene in rabbits

The widespread use of butylated hydroxyanisole (I) and butylated hydroxytoluene (II) as food antioxidants recently has been criticized by the Food and Drug Administration because of their pharmacological and toxicological effects. Interest also has arisen recently in the use of these compounds as anticancer agents. The purposes of this study were to evaluate the pharmacokinetics of I and II in rabbits and to compare their physicochemical properties with their disposition kinetics. It was found that I has a disposition half-life of approximately 1 hr, compared to 11 days for II. These differences are explained in terms of their lipid solubility and protein binding characteristics.

Multicompartment pharmacokinetic analysis and simulations using a programmable calculator

This paper describes the use of a programmable calculator (HP-97), for fitting plasma concentration profiles to 1 and 2 compartment open models and calculating fitted and derived parameters together with estimates of steady state plasma drug levels following various dosage regimens in clinical settings.

GLC determination of butylated hydroxyanisole in human plasma and urine

A highly sensitive and specific GLC method was developed for the analysis of butylated hydroxyanisole, a commonly used antioxidant. Concentrations below 100 ng/ml could be detected in human plasma and urine. Preliminary pharmacokinetic studies demonstrated that, upon administration of 100 mg po, butylated hydroxyanisole was quickly absorbed and removed from the plasma with a high degree of intersubject variability.

Binding of butylated hydroxyanisole to human albumin using a novel dynamic method

To study the interaction of butylated hydroxyanisole with various body tissues, a fully automated dynamic method was developed for the determination of plasma protein binding constants at 37 degrees, using membrane filtration equipment designed for dissolution rate studies. Appropriate equations were derived for the calculation of the free drug concentration from comparative diffusion rates across sealed dialysis sacs. A monoexponential equation described the diffusion in the absence of proteins, and a biexponential equation was fitted to diffusion from the drug-protein complex. The Scatchard and double-reciprocal plots were developed for butylated hydroxyanisole. A high degree of reproducibility was obtained for the calculation of protein binding constants (K = 2.4 - 2.9 X 10(4) and n = 1.4 - 1.32). The magnitude of these binding-constants suggests that any change in protein binding can have a significant effect on the distribution of butylated hydroxyanisole throughout the body, such as may be brought about by the common variations in the amount ingested.

Thermodynamics of mercaptopurine dehydration

The hydrate form of mercaptopurine was shown to undergo peritectic decomposition of its water molecule, localized dissolution, and dehydration around 125 degrees. The anhydrate form was prepared by a thermal method, whose effectiveness was confirmed by X-ray diffraction, NMR spectroscopy, and differential scanning calorimetry. The activation energy for mercaptopurine dehydration calculated by various methods ranged from 45.74 to 63.04 kcal/mole. The dehydration enthalpy was calculated to be 8.27 kcal/mole by differential scanning calorimetry. The solution enthalpy for the hydrate was calculated to be 4.85 kcal/mole from its saturation solubility and differential scanning calorimetry. Anhydrate solubility in water was calculated based on initial dissolution rate data since the anhydrate converts to hydrate in aqueous media. The high degree of stability against interconversion of the hydrate and anhydrate forms and the higher solubility of the anhydrate suggest that use of the anhydrate might improve mercaptopurine bioavailability.

Application of a programmable calculator in data fitting according to one and two compartment open models in clinical pharmacokinetics

The plasma or blood concentration profiles are fitted by single or two compartment open models using log-linear regression analyses. For two compartment models, "feathering" is performed at 95% equilibration time obtained from raw pharmacokinetic data. The equations have been programmed onto a Texas Instrument SR 52 pocket calculator and recorded on 8.5 X 1.7 cm magnetic strips, facilitating drug dosage regimen calculations through individual patient titrations in a clinical setting.

Fluorocarbon aerosol propellants XI: Pharmacokinetics of dichlorodifluoromethane in dogs following single and multiple dosing

A three-compartment open model was proposed for the disposition of dichlorodifluoromethane in dogs with average half-lives of 1.47, 7.95, and 58.5 min for the three disposition phases. This proposal is contrary to several studies that monitored blood levels for a shorter period. An analysis of the tissue compartment distribution following a single dose showed that about 1.5 hr was required to achieve pseudodistribution equilibration, following which more than 90% of the dose remaining in the body was retained in the tissue compartments. The pulmonary clearance and volumes of distribution were calculated considering the first-pass effect through the lungs. The volume of distribution after reaching pseudodistribution equilibrium was approximately 10 times the body weight in terms of the blood concentration, and about 68% of the propellant was cleared from the blood passing through the lungs in each cycle. Disposition of the propellant followed dose-independent kinetics after multiple dosing. No volatile metabolites were detected in the blood using GC.

Volume of distribution and tissue level errors in instantaneous intravenous input assumptions

A comparison was made between instantaneous input assumption and short-term zero-order infusion for 1 and 2 min for several drugs showing fast distribution to the tissue compartments. The errors ranged from 9 to 40% for the volume of the central compartment, from 0.7 to 11% for the volume of distribution following pseudo-distribution equilibrium, and from 11 to 34% for the volume of distribution change at the end of the 2-min infusion period. Significant errors in the tissue levels also were observed. It was suggested that all intravenous administrations be considered as short-term zero-order inputs.

Comparison of observed and predicted first-pass metabolism of nortriptyline in humans

The extent of first-pass metabolism of nortriptyline, calculated by comparing the areas under the plasma concentration-time curves following intravenous and oral dosing in six individuals, varied from 41 to 54%. Theoretically predicted values ranged from 41 to 61% based on a plasma flow model, indicating that the clearance takes place mainly from the plasma, which does not represent the whole blood concentration.

Pharmaceutical applications of solid dispersion systems: dissolution of griseofulvin-succinic acid eutectic mixture

The dissolution profile of the griseofulvin-succinic acid eutectic mixture system was evaluated using the powder and constant-surface are tablet methods. Factors contributing to the enhancement of griseofulvin dissolution from the dispersion in succinic acid are discussed. Contrary to the original proposal of Sekiguchi and coworkers, dissolution rates of driseofulvin from solid dispersions were found to be markedly affected by the particle size of solid dispersions.

Comparison of observed and predicted first-pass metabolism of imipramine in humans

The first-pass metabolism of imipramine was calculated based on the dose, hepatic blood flow, and total area under the plasma-time curve after oral administration of 0.71 +/- 0.03 mg/kg of imipramine to four individuals suffering from mild depression. The predicted values of first-pass metabolism ranged from 37 to 68%, consistent with experimentally derived estimates.

Errors involved in instantaneous intravascular input assumptions

A comparative evaluation of a zero-order input and the generally accepted instantaneous intravascular input assumption is made for two- and three-compartment open model systems. Equations are derived and a nomogram is prepared to calculate the magnitude of error involved in instantaneous input assumptions. It is suggested that all intravascular administrations be considered as zero-order inputs.

Volume of distribution as a function of time

A single definition for all volume terms in pharmacokinetic modeling is proposed; this parameter is considered as a function of time. This definition will represent the kinetic nature of pharmacokinetic models and will provide a highly sensitive parameter for correlation with pharmacological responses.

Effect of polyethylene glycol 4000 on dissolution properties of sulfathiazole polymorphs

The dissolution rates of the two polymorphic forms of sulfathiazole containing polyethylene glycol 4000 were significantly different in water. The effect of agitation on the dissolution rates also was studied. At higher stirring speeds, the dissolution rates of the stable form were affected more than the metastable form. A high concentration of polyethylene glycol 4000 seemed to affect the dissolution properties of the metastable polymorph more than the stable polymorph.

Fluorocarbon aerosol propellants X: pharmacokinetics of dichlorotetrafluoroethane in dogs

An intravenous dosage form of dichlorotetrafluoroethane, a common fluorocarbon aerosol propellant, was formulated in polyethylene glycol 400 for single dosing to unanesthetized dogs. A three-compartment open model was proposed for the disposition of this compound in dogs, with average half-lives of 1.3, 9.6, and 50.8 min for the three disposition phases. An analysis of tissue compartment distribution following a single dose showed that it took about 2 hr to achieve pseudo-distribution equilibration, following which more than 90% of the propellant remaining in the body was retained in the tissue compartments. Pulmonary clearance and volumes of distribution were calculated considering the first-pass effect through the lungs. The volume of distribution was approximately 10 times the body weight in terms of blood concentration, and about 84% of the propellant was cleared from the blood passing through the lungs in each cycle.

Fluorocarbon aerosol propellants. VI: Interspecies differences in solubilities in blood and plasma and their possible implications in toxicity studies

Solubilities of the three most commonly used fluorocarbon aerosol propellants were determined in the blood and plasma of humans, monkeys, dogs, rats, and mice. Differences as large as approximately fourfold in blood and more than 33-fold in plasma were found in different species. The partitioning of fluorocarbons between blood cells and plasma showed even greater differences between species. An indirect method was suggested for the calculation of plasma concentrations from total blood concentrations. A comparative evaluation was reported for the nonprotein bound fractions of fluorocarbons in the blood samples of various species. A correlation was drawn for the pharmacokinetic properties of the fluorocarbons within and between species, and a rationale was provided for the extrapolation of toxicity data from animals to humans.

Fluorocarbon aerosol propellants IV: pharmacokinetics of trichloromonofluoromethane following single and multiple dosing in dogs

An intravenous dosage form of trichloromonofluoromethane, a common aerosol propellant, was formulated in polyethylene glycol 400 for single and multiple dosing to unanesthetized dogs. A three-compartment open model was proposed for disposition of this compound in dogs with average half-lives of 3.2, 16, and 93 min for three disposition phases. This finding is contrary to several reports where blood levels were monitored for shorter periods. A computer analysis of tissue compartment distribution following a single dose showed that about 2 hr was required to achieve pseudodistribution equilibration, following which more than 90% of the dose remaining in the body was retained in tissue compartments. Pulmonary clearance and volumes of distribution were calculated considering first-pass effect through the lung. The volume of distribution was approximately six times the body weight in terms of blood concentrations, and about 30% of the propellant was cleared from blood passing through the lung in each cycle. Disposition of propellant followed dose-independent kinetics after multiple dosing, and accumulation in tissues continued for a much longer period, resulting in high tissue compartment levels.