Exposure to per- and polyfluoroalkyl substances and bone health: a systematic review and meta-analysis

Perfluoroalkyl substances (PFAS) as a large group of synthetic compounds widely contaminated the environment and lead to health problems. However, the correlation between PFAS exposure, bone health parameters and osteoporosis remains controversial. Therefore, we conducted a systematic review and meta-analysis of published literature to evaluate the effects of PFAS on human bone health. All observational studies were collected up to 2 December 2023. A total of 2096 articles were retrieved. Of these, 21 articles investigated the association between PFAS exposure and human bone health. However, only 10 studies were included in the final meta-analysis. Doubling of serum perfluorooctanoic acid (PFOA) (β = -0.11, 95% confidence interval (CI): -0.18, -0.05) and perfluorooctane sulfonic acid (PFOS) (β = -0.06, 95% CI: -0.11, -0.01) levels showed significant negative correlations with total body less head bone mineral density (TBLH-BMD). Subgrouping showed that only perfluorohexane sulfonate (PFHxS) (odds ratio [OR] = 1.37, 95% CI: 1.12, 1.68) was correlated with osteoporosis.

A comparative study of response surface methodology and artificial neural network based algorithm genetic for modeling and optimization of EP/US/GAC oxidation process in dexamethasone degradation: Application for real wastewater, electrical energy consumption

Dexamethasone (DXM) is a broadly used drug, which is frequently identified in the water environments due to its improper disposal and incomplete removal in wastewater treatment plant. The inability of conventional treatment processes of wastewater causes that researchers pay a great attention to study and develop effective wastewater treatment systems. This work deals with the study of integrated electro-peroxone/granular activated carbon (EP/US/GAC) process in the degradation of dexamethasone (DXM) from a water environment and the remediation of real pharmaceutical wastewater. Two approaches of response surface methodology based on central composite design (RSM-CCD) and artificial neural network based on algorithm genetic (ANN-GA) were employed for modeling and optimization of the process. Both the models presented significant adequacy for modeling and prediction of the process according to statistical linear and nonlinear metrics (R2 = 0.9998 and 0.9996 and RMSE = 0.2128 and 0.1784 for ANN-GA and RSM-CCD, respectively). The optimization study provided the same outcomes for both ANN-GA and RSM-CCD approaches, where approximately complete DEX oxidation was achieved at pH = 9.3, operating time = 10 min, US power = 300 W/L, applied current = 470 mA, and electrolyte concentration = 0.05 M. A synergistic study signified that the EP/US/GAC process made an 82% synergy index as compared to the individual US and EP processes. The calculated energy consumption for the integrated process was achieved to be 2.79 kW h/gCOD. Quenching test by tert-butanol and p-benzoquinone revealed that HO• radical possessed the largest contribution in DEX degradation. The efficiency of EP/US/GAC process in the remediation of real pharmaceutical wastewater showed a significant decline in COD content (92% removal after 180 min), and the ratio of initial BOD/COD ratio of 0.27 was elevated up to 0.7 after 100 min treatment time. The performance stability of EP/US/GAC system showed no remarkable drop in removal efficiency, and leakage of lead ions from the anode surface was negligible and below WHO guideline for drinking water. Generally, this research work manifested that the integrated EP/US/GAC system elevated the degradation efficiency and can be proposed as a pretreatment step before biological treatment processes for the remediation of recalcitrant wastewaters.

The association between exposure to polycyclic aromatic hydrocarbons and birth outcomes: A systematic review and meta-analysis of observational studies

Exposure to polycyclic aromatic hydrocarbons (PAHs) has been linked to adverse birth outcomes; however, to date, the available studies on such relations, with the exception of birth weight, has not been systematically synthesized. We conducted a systematic review and meta-analysis of the available observational studies on the association of maternal exposure to PAHs and their metabolites during pregnancy with indicators of fetal growth and gestational age at delivery. We searched Web of Science, PubMed and Scopus systematically for all relevant published papers in English until 13 January 2023. Random effects meta-analysis was applied to synthesize the association estimates. Publication bias was assessed using Egger's regression. A total of 31 articles were included in our review (n = 703,080 participants). Our quality assessment of reviewed papers showed that 19 research had excellent, nine had good, and three had fair quality. Most of the reviewed studies on exposure to PAHs and their metabolites with gestational age and preterm birth (seven studies) reported no statistically significant association. Eight studies were eligible for our meta-analysis. Results of the meta-analysis indicated that higher levels of maternal urinary 1-OHP was associated with lower birth weight, birth length and head circumference and a higher risk of low birth weight (LBW). However, these associations were not statistically significant. Similarly, the combined association between maternal urinary 1-OHP and newborn's Ponderal index (PI) and Cephalization index were not statistically significant. Overall, our systematic review and meta-analysis suggested a potential adverse impact of exposure to PAHs on LBW, HC, and CC; however, further studies are required to be able to draw concrete conclusions on such associations.

Vaccination is the most effective and best way to avoid the disease of COVID-19

Most of the vaccines that are effective against SARS-CoV-2 have used the following functional strategies: inactivated viruses, live attenuated viruses, viral vector-based vaccines, subunit vaccines, recombinant proteins, and DNA/RNA vaccines. Among the vaccines that stimulate the host's immune system with the help of DNA are: undergoing Phase 2/3 trials including INO-4800 (International Vaccine Institute; Inovio Pharmaceuticals), Symvivo, Canada-COVID19 (AnGes, Inc.); GX-19 (Genexine, Inc.). BNT162b2 and mRNA-1273 vaccines were made by BioNTech/Pfizer/Fosun Pharma group and Moderna/NIAID group, respectively, which are considered as types of RNA vaccines. Vaccines that are based on the viral vector are AstraZeneca, Sputonium, and Johnson-Jensen. Among the inactive viral vaccines, the following can be mentioned: CoronaVac (Sinovac) WIBP vaccine (Wuhan Institute of Biological Products, Sinopharm), BBIBPCorV (Beijing Institute of Biological Products, Sinopharm), BBV152/Covaxin (Bharat Biotech, ICMR, National Institute of Virology) And among the protein-based/subunit vaccines, the following can be counted: NVX-CoV2373: (Novavax); SCB-2019 vaccine (Clover Biopharmaceuticals AUS Pty Ltd.); Covax-19 (GeneCure Biotechnologies; Vaxine Pty Ltd.) mRNA vaccines, viral vector vaccines, and protein subunit vaccines cannot cause disease because these vaccines stimulate the immune system to produce antibodies against virus proteins instead of the virus itself (or its antigen). MRNA vaccines increase SARS-CoV-2 proteins and ultimately stimulate the production of T and B lymphocytes. The epidemic of HCoVs and their destructive and harmful effects on life has caused the scientific community to seek the production of an effective and efficient vaccine before its catastrophic release. We all need to know that none of us will be healed until the other is healed. The purpose of this review article is to present a selection of existing knowledge in the field of fighting and preventing the coronavirus.

Evaluating the results of eyebrow lift by combining methods of subcutaneous flap and thread support in patients with droopy eyebrows

BACKGROUND

Brow lift also known as eyebrow lift was first described in 1919, and since then, many changes have been made in the methods of doing it, although there is still no agreed method of absolute superiority for eyebrow lift. Most previous studies have reported the results generally qualitatively and based on patient or surgeon satisfaction. In this study, by combining two less complicated methods of eyebrow lift, we have evaluated the quantitative results.

METHOD

Before the surgery, a standard photograph of the face was taken. The vertical distance between the tail of the eyebrow and interpupillary line was determined.

RESULTS

This study was performed on 15 females with a mean age of 38.27 ± 6.82 years. The mean distance between the eyebrow and interpupillary line by photographic measurement before surgery, 3 weeks, and 6 months after surgery was, respectively, 10.45 ± 1.74, 15.72 ± 1.77, and 13.53 ± 1.69 mm using the tail of the eyebrow and 18.47 ± 1.67, 23.33 ± 1.57, and 21.55 ± 1.66 mm using the crown of the eyebrow. In the clinical measurement, the eyebrow tail was 11.98 ± 1.75, 19.22 ± 1.73, 17.35 ± 1.68 and 15.13 ± 1.76 mm away from the pupil line, and the crown of eyebrow was 20.45 ± 1.90, 27.12 ± 1.58, 25.00 ± 1.80, and 23.35±1.78 mm. There is a significant difference between the distance of the tail of the eyebrow and the crown of the eyebrow in both measurement methods (photographic and clinical) at different times (p-value <0.001).

CONCLUSION

Performing eyebrow lift with the Pretrichial method has many comparative advantages to other methods. Additionally, eyebrow lift with the thread support is a less invasive method.

A case of multidrug-resistant Mycobacterium simiae in an elderly woman

Mycobacterium simiae is an emerging and spreading pathogen in Iran and little data about its drug susceptibility test (DST) and no standard treatment regimen are available. We report a case of multidrug-resistant M. simiae respiratory infection in a 65-year-old woman with a history of previous Mycobacterium tuberculosis infection. The patient was treated with clarithromycin, levofloxacin, and cotrimoxazole for one year and eventually died while still suffering from respiratory problems. For DST, broth microdilution method was used according to the Clinical and Laboratory Standards Institute guidelines as well as molecular DST in clinical isolate. Mycobacterium simiae was resistant to streptomycin, moxifloxacin, clarithromycin, and cotrimoxazole antibiotics and was sensitive to clofazimine and amikacin antibiotics. Inappropriate use of antibiotics without determining the pattern of antibiotic resistance increases the likelihood of resistance and, for resistant specimens, the need to review the treatment protocol and replace antibiotics. Effectiveness based on antibiotic resistance pattern is essential.

Mycobacterium simiae pulmonary infection: a case series and literature review

Incidence of Mycobacterium simiae pulmonary infection is increasing and diagnosis and treatment are challenging. We surveyed the clinical features, risk factors, diagnosis, and management in 20 patients from northeastern Iran diagnosed by line probe assay and confirmed by sequencing the ITS (16S-23S) rRNA region and carried out a literature review using the keywords "pulmonary infection" and "Mycobacterium simiae." The mean age of patients was 55.1 years, with 80% female and 90% diagnosed by sputum. Clinical symptoms included severe cough (90%), sputum production (70%), haemoptysis (50%), and chest pain (35%). Comorbidities included a history of tuberculosis (60%), smoking (40%), or chronic obstructive pulmonary disease (20%). Patients were treated with levofloxacin, clarithromycin, and co-trimoxazole. Except for two patients, the clinical symptoms improved. Mycobacterium simiae pulmonary infection is increasing in people with underlying diseases. Although choosing the most appropriate treatment remains a challenge, combining successful treatments could be useful in treating these patients.

Mycobacterium szulgai pulmonary infection in a vitamin D-deficient patient: A case report

Closer attention should be paid to vitamin D status in patients with mycobacterial diseases.

An overview of yeast probiotics as cancer biotherapeutics: possible clinical application in colorectal cancer

The previous reports have established a strong link between diet, lifestyle, and gut microbiota population with the onset of the colorectal cancer (CRC). Administration of probiotics has become a particular interest in prevention and treatment of CRC. As potential dietary complements, probiotics might be able to lower the risk of CRC and manage the safety of traditional cancer therapies such as surgery, radiation therapy, and chemotherapy. This review investigates the promising effects of probiotics as biotherapeutics, with due attention to possible clinical application of yeast probiotics in prevention and treatment of CRC. In addition, various underlying anti-cancer mechanisms are covered here based on scientific evidence and findings from numerous experimental studies. Application of probiotics as biotherapeutics in CRC, however, needs to be approved by human clinical trials. It is of prime concern, to find potential probiotic strains, effective doses for administrations and regimes, and molecular mechanisms involved in prevention and treatment.

Evaluating the head posture of dentists with no neck pain

INTRODUCTION

Dentistry is one of the professions that requires a high degree of concentration during the treatment of patients. There are many predisposing factors, affecting dentists when working on the patient's teeth, including neck flexion, arm abduction and inflexible postural positions, which may put them at the risk of developing musculoskeletal disorders related to the neck. Although dentists with long records of service show different levels of pain and discomfort in their necks, there is no evidence regarding whether younger dentists report neck pain before the onset of an abnormal condition in this region, including forward head posture (FHP). Discovering any alteration in the head posture of dentists might confirm one of the reasons for neck pain in this population.

MATERIALS

Forty one dentists with no neck pain and forty controls having jobs other than dentistry who had no risk factors related to head posture voluntarily participated in the present study. A standard method was used to measure the cervical curve in these two groups.

RESULTS

There was no significant difference between the mean values of cervical curve in dentists and the control group (p > 0.05). There was also no significant difference between cervical curve values in dentists working for either 5-8 years or 8-12 years (p > 0.05). The only significant difference was observed in mean cervical curve values of men and women in the dentist group (p < 0.05).

CONCLUSION

No alteration of cervical curve in the dentist group compared to controls might be due to absence of pain sensation in the dentists in the current study. In other words, this group might have not yet experienced sufficient change in head posture to experience significant pain in their neck region.

Conversion of dehydroepiandrosterone sulfate at physiological plasma concentration into estrogens in MCF-7 cells

Metabolism of dehydroepiandrosterone (DHEA), its sulfate (DHEAS), and androstene-3,17-dione (delta(4)) was performed at their physiological plasma concentrations in MCF-7 cell cultures (1 microM, 10 and 2 nM, respectively). Final metabolic products of these steroids were separated by HPLC-radioactive flow detection and identified by LC/MS or MS/MS. Typical and specific mass fragmentation spectra identified the presence of estrone (E(1)), 17beta-estradiol (E(2)), delta(4), DHEA, 5-androstene-3beta,17beta-diol (delta(5)), and testosterone as principal DHEAS metabolites. Other steroids, such as androstenedione, androsterone, and DHEA fatty acid esters at very low concentrations (from pM to nM), were also obtained after steroid incubation. This highly specific method allowed us to conclude whether a metabolite and enzymatic activity of interest were present in MCF-7 cells or not. We also showed that DHEAS at its physiological plasma concentration may be converted into estrogens and estrogen-like compounds in breast cancer cells. The estrogenic action of DHEAS on breast cancer cells was also measured by bioluminescence in a stably transfected human breast cancer MCF-7 cell line with a reporter gene that allowed expression of the firefly luciferase enzyme under the control of an estrogen regulatory element.

Determination of LSD and N-demethyl-LSD in urine by liquid chromatography coupled to electrospray ionization mass spectrometry

A sensitive and highly specific method for the determination of LSD and N-demethyl-LSD in urine, using combined liquid chromatography and mass spectrometry (LC-MS) with electrospray ionization, has been developed. Extrelut-3 extraction cartridges were used for a basic sample clean-up. Elution was obtained by toluene-diethyl ether (60:40, v/v). A Nucleosil C18 (150 X 1 mm I.D.) reversed-phase column was used for the chromatographic separation, together with a mixture of 2 mM ammonium formate buffer (pH 3) and acetonitrile (70:30, v/v) as mobile phase. Recoveries were 93 and 80%, detection limits 0.025 and 0.035 ng/ml for LSD and N-demethyl-LSD, respectively. Intra-assay precision, studied at four concentrations, was better than 9% at the ng/ml range and better than 14% at 0.10 ng/ml for both compounds. Limits of quantitation were 0.05 and 0.10 ng/ml for LSD and N-demethyl-LSD, respectively. Reproducibility was good and linearity excellent for LSD in the range from 0.05 to 20 ng/ml (r>0.9999, n=7).

Tungsten determination in biological fluids, hair and nails by plasma emission spectrometry in a case of severe acute intoxication in man

A healthy 19-year-old recruit in a French artillery regiment drank 250 mL of a mixture of beer and wine that had rinsed in a hot 155-mm gun-barrel. Fifteen minutes later, he complained of nausea followed by seizures. He was comatose for 24 h, presenting signs of encephalopathy. A moderate renal failure was noted initially and worsened to an extensive tubular necrosis with anuria on the day after the incident. The first toxicological investigations only showed a 0.31 g/L blood ethanol. Then inductively-coupled plasma (ICP) emission-spectrometry revealed very high concentrations of tungsten in the "beverage" as well as in gastric content, blood and urine (1540 mg/L, 8 mg/L, 5 mg/L, and 101 mg/L, respectively). The nature of the metal was confirmed by ICP coupled to mass spectrometry. A simple and reliable ICP quantitative assay of tungsten in biological fluids, hair and nails was then developed. It showed high blood levels (> 0.005 mg/L) until day 13 in spite of six hemodialyses, and in urine until D33. Tungsten was also incorporated in hair and nails. To the best of our knowledge, such an intoxication has never been reported before though this drinking seems to be traditional in the French Artillery. It has probably been favored by the unusually high volume of beverage absorbed and by the new alloy of the gun, containing tungsten. The clinical evolution was satisfactory over weeks and the patient was declared totally cured after five months.

Simultaneous determination of lidocaine and bupivacaine in human plasma: application to pharmacokinetics

High-performance liquid chromatography has been applied to the simultaneous determination of lidocaine and bupivacaine levels in human plasma, using etidocaine as internal standard. The method was found to be linear in the range 10-2,000 micrograms/l for lidocaine and 20-1,000 micrograms/l for bupivacaine. Within-day and day-to-day coefficients of variation were generally lower than 12%. The method was applied to a pharmacokinetic study of lidocaine and bupivacaine during peribulbar anesthesia in ocular surgery. Both compounds displayed a slow apparent elimination rate. The method described here permitted the determination of the complete pharmacokinetic profiles of the two anesthetics, although they were administered at quite different doses.

Determination of buprenorphine and norbuprenorphine in whole blood by liquid chromatography-mass spectrometry

A sensitive and highly specific method for the determination of buprenorphine and norbuprenorphine in postmortem and hemolyzed whole blood using combined liquid chromatography and mass spectrometry (LC-MS) with electrospray ionization was developed. After enzymatic hydrolysis and deproteinization with acetonitrile, Extrelut-3 cartridges were used for a preliminary basic sample cleanup. Elution by toluene-ether (50:50, v/v) was followed by an acid wash with 0.05M H3PO4 and a basic re-extraction into ether. A Nucleosil C18 (150 x 1-mm i.d.) reversed-phase column was used for the chromatographic separation together with a mixture of 2mM ammonium formate buffer (pH 3) and acetonitrile (55:45, v/v) as the mobile phase. Recoveries were between 56 and 60%, and detection limits were 0.05 ng/mL for both analytes. The coefficient of variation for repeatability was lower than 4%. Limits of quantitation were 0.1 ng/mL for buprenorphine and norbuprenorphine. Reproducibility was good, and linearity was excellent in the range of 0.1 to 100 ng/mL (r > 0.9999, n = 7).

Applications of liquid chromatography--mass spectrometry in analytical toxicology: a review

Liquid chromatography-mass spectrometry (LC-MS), after long-term development that has introduced seven major interfacing techniques, is finally suitable for application in the field of analytical toxicology. Various compound classes can be analyzed, and sensitivities for more or less polar analytes that are as good as or better than those of gas chromatography-mass spectrometry can be obtained with modern interfaces. In addition, because ionization is often softer than classical electron impact, some LC-MS interfaces are able to handle fragile species that are otherwise not amenable to MS. This review is intended to present LC-MS to less familiarized readers and to give an extensive overview of the application of the different coupling techniques to doping agents, drugs of abuse, forensic analysis, toxic compounds of various nature, and several toxicologically relevant therapeutic drugs. Experimental parameters such as the interfaces used, ionization methods, detection limits, and experimental details for exemplary applications are given.

Determination of haloperidol and its reduced metabolite in human plasma by liquid chromatography-mass spectrometry with electrospray ionization

A sensitive and accurate liquid chromatographic-electrospray mass spectrometric (LC-ES-MS) method for the determination of haloperidol (H) and reduced haloperidol (RH) in human plasma is presented, using chlorohaloperidol as the internal standard. A 2-ml volume of plasma was subjected to basic (NaOH) extraction, acid (HCl) back-extraction, acid wash and basic (NaOH) re-extraction. The extraction solvent was hexane-isoamyl alcohol (99:1, v/v) for the whole procedure. A Nucleosil C18 column (150 x 1 mm) was used for high-performance liquid chromatography, together with 2 mM HCOONH4-acetonitrile (55:45, v/v; pH 3.0) as the mobile phase. For each drug, four characteristic ions were monitored. Linearity was assessed in the ranges 0.1-50 and 0.25-50 ng/ml for H and RH, respectively. Recoveries were 58 and 70% and detection limits were 0.075 and 0.100 ng/ml for H and RH, respectively. Correlation coefficients were better than 0.999 for both compounds. R.S.D.s for repeatability and reproducibility at 0.25 ng/ml were 11.1 and 8.5% for H and 9.4 and 11.2% for RH, respectively. One of the main advantages of (LC-ES-MS) over other detection systems is the increase in selectivity obtained by monitoring three ions of confirmation for each of the drugs.

The role of hyaluronidase on lidocaine and bupivacaine pharmacokinetics after peribulbar blockade

Orbital regional anesthesia is the only circumstance where hyaluronidase is routinely added to local anesthetics to accelerate the onset of the block. The aim of this study was to compare the pharmacokinetics of lidocaine and bupivacaine with or without hyaluronidase for peribulbar blockade. Twenty-one patients scheduled for cataract surgery with lens implantation were included in this prospective randomized study. Peribulbar blocks were achieved with plain bupivacaine 0.5% (5.5 mL), lidocaine 2% (5.5 mL), and hyaluronidase (100 IU = 2 mL) (n = 10) ir sterile water (2 mL) (n = 11). Plasma bupivacaine and lidocaine concentrations were measured by high-performance liquid chromatography at regular intervals from the end of the local anesthetic injection until the 360th minute. Maximum plasma concentration (Cmax) and time to reach Cmax (Tmax) were obtained for all the patients except one who needed a supplementary injection and was excluded from the study. The time to onset and duration of the analgesia and akinesia were monitored at the times of sampling. Motor blockade was incomplete in two patients in each group without affecting surgery. The Tmax and absorption half-life (t1/2a) of lidocaine and bupivacaine were not different within each group (P > 0.05). The Tmax of lidocaine was shorter in the presence of hyaluronidase (17.1 +/- 2.6 min vs 32.7 +/- 6.0 min) as well as the Tmax of bupivacaine (16.8 +/- 3.0 min vs 26.5 +/- 4.4 min). The Cmax of lidocaine and bupivacaine were not modified by the addition of hyaluronidase. The clearance, terminal half-life, and volume of distribution were not different between groups. The absorption of lidocaine and bupivacaine from the peribulbar space are hastened by the addition of hyaluronidase. The Tmax of lidocaine is not different from that of bupivacaine within each group suggesting that the absorption of local anesthetics is minimally influenced by the liposolubility of the drugs. Moreover, hyaluronidase influences the absorption kinetics of both lidocaine and bupivacaine in the same manner.

A screening procedure for the determination of 13 oral anticoagulants and rodenticides

A technique for the simultaneous identification and quantitation of 13 hydroxycoumarin and indandione anticoagulant drugs and rodenticides from human serum by reversed-phase liquid chromatography with diode-array detection has been developed. High-performance liquid chromatography was performed using gradient elution with an acetonitrile and phosphate buffer on a Nucleosil ODS column. Ultraviolet spectra from 200 to 400 nm were recorded on-line during the analysis and compared with spectra stored in a library. For the spiked 2 mL of serum, acidic and alkaline liquid-liquid double extraction with diethylether-ether acetate (50:50, v/v) was conducted, and recoveries greater than 60% for most compounds were found. The detection limit was approximately 25 or 50 ng/mL for all components except for difethialone and fluindione, for which it was approximately 100 ng/mL. The standard calibration curves were linear from the detection limit to 5000 ng/mL. The within-run precision coefficient of variation (CV) was less than 10%, and the between-run precision CV was less than 20%.

Analytical findings in a suicide involving sodium azide

A 47-year-old laboratory assistant ingested approximately 9 g of sodium azide powder and died 4 h later at a hospital. A high-performance liquid chromatographic method using diode-array detection has been developed for the determination of an azide benzoyl derivative in blood (after a simple deproteinization) and in several tissues (after homogenization in a neutral buffer and deproteinization of the supernatant). The blood concentration in this case was lower than those previously published. The highest azide concentration was found in lung tissue. A complete toxicological screening revealed the presence of cyanide in blood, which has been previously reported twice, but for the first time, it was confirmed by mass spectrometry. Whether the production of cyanide in the presence of azide took place in vivo or postmortem remains unknown; the nature of the metabolic pathway involved also remains unknown.

A screening procedure for the determination of 13 oral anticoagulants and rodenticides

A technique for the simultaneous identification and quantitation of 13 hydroxycoumarin and indandione anticoagulant drugs and rodenticides from human serum by reversed-phase liquid chromatography with diode-array detection has been developed. High-performance liquid chromatography was performed using gradient elution with an acetonitrile and phosphate buffer on a Nucleosil ODS column. Ultraviolet spectra from 200 to 400 nm were recorded on-line during the analysis and compared with spectra stored in a library. For the spiked 2 mL of serum, acidic and alkaline liquid-liquid double extraction with diethylether-ether acetate (50:50, v/v) was conducted, and recoveries greater than 60% for most compounds were found. The detection limit was approximately 25 or 50 ng/mL for all components except for difethialone and fluindione, for which it was approximately 100 ng/mL. The standard calibration curves were linear from the detection limit to 5000 ng/mL. The within-run precision coefficient of variation (CV) was less than 10%, and the between-run precision CV was less than 20%.

Population pharmacokinetics of amikacin in intensive care unit patients studied by NPEM algorithm

The population pharmacokinetics of amikacin was studied in 40 intensive care unit patients (212 plasma concentrations) by NPEM algorithm using a one-compartment model. The population was best characterized by the following pharmacokinetic parameters: renal clearance relative to creatinine clearance (Cs = 0.96 +/- 0.33), and either the total volume of distribution (Vd = 23.9 +/- 7.0 l) or the volume of distribution relative to body weight (Vs = 0.36 +/- 0.10 l.kg-1. The volume of distribution was increased with respect to the usual value of 0.25 l.kg-1. The statistical distribution of these pharmacokinetic parameters was approximately gaussian, with no significant correlation between volume of distribution and clearance. The medians and standard deviations of Cs and Vs were used as reference population values to estimate the pharmacokinetics of amikacin in a second group of 29 patients by the bayesian method, with two blood samples per patient. For each patient, the fitted parameters were able to predict the plasma concentrations of amikacin during the next 72 h with no significant bias and good precision (2.9 mg.l-1 for peaks and 0.5 mg.l-1 for troughs). This study confirms the ability of the NPEM algorithm to provide reference population values for use in bayesian monitoring of aminoglycoside therapy.

[Retrograde cerebral perfusion for replacement of the aortic arch. Apropos of a case]

The authors report a case of cerebral protection with retrograde cerebral perfusion during aortic arch surgery. The duration of retrograde cerebral perfusion and the favorable neurological outcome seem to confirm the promising results of this technique developed in Japan.

Effects of short-term tamoxifen administration in patients with invasive cervical carcinoma

Cervical cancer is not considered a hormone-responsive tumor in spite of the presence of estrogen receptors (ER) and progesterone receptors (PgR) in some of them. Endocrine treatments have not achieved clinical responses, however, tamoxifen has been reported to induce PgR and to inhibit cell growth of many cervical carcinoma cell lines. In this study we investigated whether tamoxifen administration affects the histopathological characteristics of cervical cancer and the expression of ER, PgR, HER-2/neu and p53 protein. Nineteen patients with invasive cervical cancer free of previous treatments were studied. The triphenylethylene antiestrogen tamoxifen was given orally during 10 days (20 or 40 mg/day). Pre- and post-tamoxifen biopsies were evaluated using slides stained with hematoxylin and eosin and immunostained (ER, PgR, HER-2/neu, p53, PCNA, keratin, heat shock protein 27,000 daltons). Estrogen receptors were present in 37% and PgR in 16% of the biopsies from untreated patients. Only one case that was PgR-negative before tamoxifen administration showed weak PgR-positivity following antiestrogen administration. No obvious changes were observed in ER, HER-2/neu and p53 proteins. A statistically significant decrease in the number of mitotic figures was obtained in 16% (3/19) of the post-tamoxifen biopsies and two of them showed higher differentiation. The results showed that tamoxifen did not induce changes in estrogen-regulated proteins in cervical cancer. However, the data showed that certain cervical carcinomas had changes in their proliferation and differentiation levels following tamoxifen administration. These findings suggest that tamoxifen may affect some cervical cancer tissues by a hormone-independent mechanism(s).

Effect of human papillomavirus infection on estrogen receptor and heat shock protein hsp27 phenotype in human cervix and vagina

In this study we have explored whether, as a consequence of human papillomavirus (HPV) infection, there is inappropriate expression of estrogen receptor and/or of a small heat shock protein of 27,000 daltons (hsp27). Estrogen receptor, hsp27, and HPV structural antigens were detected by immunocytochemistry, while HPV DNA (6/11, 16/18, 31/35/51) was determined by in situ hybridization in cervical and vaginal samples from 40 patients. Most of the samples with HPV infection without atypia showed a shift in estrogen receptor expression since this protein appeared mainly in the intermediate and superficial cell layers. In the serial sections, these layers displayed strong estrogen receptor staining, together with high HPV replication and late HPV gene expression. In the samples with HPV infection and atypia, estrogen receptors were also frequently found in the basal and parabasal cells, but almost 20% of these samples did not show estrogen receptors. The presence of high estrogen receptor expression was not dependent on a particular HPV DNA type. On the other hand, interesting modifications in hsp27 expression were observed in the HPV-infected tissues. The cytoplasm of the cells with koilocytotic changes showed very low hsp27 content. In several samples this protein appeared in the nuclei of the superficial cells, and sometimes it was also observed in the cytoplasm of the basal cells. These changes in estrogen receptor and hsp27 expression suggest that these proteins might have a role in virus-host biology.