Insights into anthropogenic impact on atmospheric inorganic aerosols in the largest city of the Tibetan Plateau through multidimensional isotope analysis

Particulate inorganic nitrogen aerosols (PIN) significantly influence air pollution and pose health risks worldwide. Despite extensive observations on ammonium (pNH4+) and nitrate (pNO3-) aerosols in various regions, their key sources and mechanisms in the Tibetan Plateau remain poorly understood. To bridge this gap, this study conducted a sampling campaign in Lhasa, the Tibetan Plateau's largest city, with a focus on analyzing the multiple isotopic signatures (δ15N, ∆17O). These isotopes were integrated into a Bayesian mixing model to quantify the source contributions and oxidation pathways for pNH4+ and pNO3-. Our results showed that traffic was the largest contributor to pNH4+ (31.8 %), followed by livestock (25.4 %), waste (21.8 %), and fertilizer (21.0 %), underscoring the impact of vehicular emissions on urban NH3 levels in Lhasa. For pNO3-, coal combustion emerged as the largest contributor (27.3 %), succeeded by biomass burning (26.3 %), traffic emission (25.3 %), and soil emission (21.1 %). In addition, the ∆17O-based model indicated a dominant role of NO2 + OH (52.9 %) in pNO3- production in Lhasa, which was similar to previous observations. However, it should be noted that the NO3 + volatile organic component (VOC) contributed up to 18.5 % to pNO3- production, which was four times higher than the Tibetan Plateau's background regions. Taken together, the multidimensional isotope analysis performed in this study elucidates the pronounced influence of anthropogenic activities on PIN in the atmospheric environment of Lhasa.

[Brachial Plexus: Dissection At The Laboratory Of Anatomy Of Bamako]

INTRODUCTION

The brachial plexus consists of the ventral twigs of the last four cervical nerves and the first thoracic nerve. It ensures the motor and sensitive innervations of the thoracic limb.

AIM

Our goal was to describe the brachial plexus of the cervical region to the middle third of the arm.

METHODOLOGY

We conducted a prospective study at the anatomy Laboratory of the Faculty of Medicine and Dentistry in Bamako from September 2016 to October 2017. We dissected the brachial plexus (PB) of 13 fresh adult corpses on both sides. The inclusion criteria were: Fresh adult corpses with cervical regions and brachial without scarring. The injected or scar-carrying corpses were not included in the cervical and brachial regions.

RESULTS

Twenty-six brachial plexus of which 18 bp in men and 8 bp in women were dissected. The average age of the subjects was 42 years (extreme: 18 and 70 years). We noted nerve block variations in 3.8%, fascicular in 3.8% and late terminal in 73.1%. The involvement of the anterior branch of the fourth spinal nerve (C4) was found in 46.2%.

CONCLUSION

The brachial plexus is the seat of many anatomical variations whose knowledge is indispensable to treat its lesions.

[Maxillary ameloblastoma at the odonto-stomatology University Hospital in Bamako]

INTRODUCTION

The aim of this study was to determine the sociodemographic, therapeutic, pathological and clinical aspects of patients with maxillary ameloblastoma at the University Hospital of Odonto-Stomatology (CHU OS) of Bamako.

MATERIALS AND METHOD

We performed a retrospective and prospective study over three years (January 2007 - December 2010), examining cases of maxillary ameloblastoma, as confirmed by clinical, associated with radiology or anatomic pathology. Data was collected from medical records, then entered and analyzed using Epiinfo.

RESULTS

Tumor lesions were found in 55 men and 43 women with a sex ratio of 1.27. Housewives represented the majority of cases with 35.7%. Maxillary radiography was performed on 96% of patients and biopsy in 66.3% of cases. The most common anatomical location was mandibular in 89.80% of cases, with the preferred area being the mandibular symphysis in 34.7% of cases. Conservative surgery was performed in 50% of patients and radical surgery in 26.5% of cases.

CONCLUSION

This study has shown a high frequency of maxillary ameloblastoma, and the fundamental benefits of early treatment, in order to minimize recidivism.

Impact of the Intra- and Inter-observer Variability in the Delineation of Parotid Glands on the Dose Calculation During Head and Neck Helical Tomotherapy

The intra- and inter-observer variability in delineation of the parotids on the kilo-voltage computed tomography (kVCT) and mega-voltage computed tomography (MVCT) were examined to establish their impact on the dose calculation during adaptive head and neck helical tomotherapy (HT). Three observers delineated left and right parotids for ten randomly selected patients with oropharynx cancer treated on HT. The pre-treatment kVCT and the MVCT from the first fraction of irradiation were selected to delineation. The delineation procedure was repeated three times by each observer. The parotids were delineated according to the institutional protocol. The analyses included intra-observer reproducibility and inter-structure, -observer and -modality variability of the volume and dose. The differences between the left and right parotid outlines were not statistically significant (p > 0.3). The reproducibility of the delineation was confirmed for each observer on the kVCT (p > 0.2) and on the MVCT (p > 0.1). The inter-observer variability of the outlines was significant (p < 0.001) as well as the inter-modality variability (p < 0.006). The parotids delineated on the MVCT were 10% smaller than on the kVCT. The inter-observer variability of the parotids delineation did not affect the average dose (p = 0.096 on the kVCT and p = 0.176 on the MVCT). The dose calculated on the MVCT was higher by 3.3% than dose from the kVCT (p = 0.009). Usage of the institutional protocols for the parotids delineation reduces intra-observer variability and increases reproducibility of the outlines. These protocols do not eliminate delineation differences between the observers, but these differences are not clinically significant and do not affect average doses in the parotids. The volumes of the parotids delineated on the MVCT are smaller than on the kVCT, which affects the differences in the calculated doses.

[Isolated mandibular fractures study's in the CHU-OS of Bamako: 55 cases]

AIMS

The aim of this study was to determine sociodemographics, clinical and therapeutic aspects in patients with isolated mandibular fractures in the Bamako dentistry teaching hospital (CHU-OS).

MATERIALS AND METHODS

We carried out restrospective study over a period of four months involving isolated mandibular fracture cases, confirmed by a clinical and radiological examination in 2006. The data were collected from medical records, entered and analyzed using Epiinfo.fr 6.0 software.

RESULTS

The lesions involved 42 men and 13 women with a sex ratio of 3.23. The age group of 21-30 was the most affected. The main cause was found to be road traffic accidents with 72.72 % of the total cases. The fractures of the mandible at the level of horizontal branch were the most frequent with 34.54 %. The orthopedic treatment was used in 72.72 % of the cases, with a good and very good results.

CONCLUSION

This study shows the high frequency of isolated fractures of the mandible mainly from road traffic accidents, as well as their occurrence among young adults.

[Volvulus of sigmoid colon: surgical treatment and prognosis in the services of General Surgery of the Point G Teaching Hospital]

OBJECTIVE

To study the therapeutic aspects and prognosis of volvulus of the sigmoid colon in surgical departments.

PATIENTS AND METHODS

Our study was retrospective from January 2000 to December 2009 (10 years). All patients who underwent sigmoid volvulus in the Point G teaching hospital surgical departments were taken into account.

RESULTS

We recorded 96 patients operated for volvulus of sigmoid over 882 cases of bowel obstruction, a rate of 10.9%. The average age was 47.2 years ± 18.9. In per-operative, there was a necrosis of the colon rate of 16.7% (14 cases). Performed surgical treatment modalities were: sigmoidectomy with primary anastomosis in 29.2% of cases (28), sigmoidectomy followed by colostomy and secondary anastomosis in 60.4% of patients (58) and 10.4% rare of simple devolvulation. The immediate postoperative period were marked by a morbidity rate of 7.3% (7 cases) and a mortality rate of 7.3% (7 cases).

CONCLUSION

In spite of various therapeutic modalities of volvulus of the sigmoid colon, the rates of postoperative morbidity and mortality are rising in the general surgery of the Point G teaching Hospital.

[Postoperative Pains: Evaluation Of Its Management In The Point G Teaching Hospital]

OBJECTIVE

To evaluate the management of postoperative pain in the Point G teaching hospital.

PATIENTS AND METHODS

We carried out a prospective study, in 2008. Inclusion criteria for the personnel: be a staff member from the department of surgery or anaesthesia reanimation; willing to fill out the questionnaire. Inclusion criteria for patients: to be operated and hospitalized in one of the departments of surgery and anaesthesia reanimation.

RESULTS

We collated the responses of 600 patients and 113 personnel. 92% of the patients underwent post-operative analgesia. The delay between the request and treatment of the patient was extensive in 92% of cases. The medical personnel and nursing staff had not received specific training on treating the pain in respectively 55% and 70% of cases. We noted an absence of informational support and of pre-established consensual protocols, written and validated on the management of postoperative pains.

CONCLUSION

The treatment of the postoperative pains shows important shortcomings within the Point G teaching hospital and these insufficiencies are found across levels.

[Common mesentery: discovered two cases of intestinal obstruction]

The purpose of this study was to describe the common mesentery in its occlusive form and practice driving before this emergency. The mesentery is a common abnormality of rotation of the primitive intestinal loop or omphalomesenteric loop during embryonic development. Two cases of intestinal obstruction by strangulation were received in urgency. They were a 55 year old man who checked himself into the emergency department and a 14 year old girl brought in by her parents. These were 2 cases of acute intestinal obstruction on incomplete common mesentery. The intestine was turned to complete common mesentery in both cases. Embryologically, it is anomalies of rotation and joining of the primitive intestine that are causing the incomplete common mesentery , the source of acute intestinal obstruction due to strangulation.

CONCLUSION

The common mesentery poses a diagnostic and therapeutic problem. Its symptomatology is that of occlusion by strangulation and the surgeon must note this before any obstruction.

[Postoperative peritonitis in the Surgery B department of the Point G hospital]

OBJECTIVE

To determine the incidence of postoperative peritonitis, and describe their clinical, paraclinical and therapeutic aspects.

PATIENTS AND METHODS

This was a retrospective study conducted between 1980 and 2010 in the Department of Surgery B of the Point G University Hospital. It focused on all patients who underwent surgical intra-abdominal in the Surgery B department.

RESULTS

We collected 25 cases of postoperative peritonitis, 84% were male subjects. The average age of patients was 37.2 years ± 17.0. The clinical picture was dominated by abdominal pain (92%), abdominal defense (92%), and fever (84%). Abdominal ultrasound played an important role in diagnosing 72% of cases. Etiologies were dominated by anastomotic leak (32%), infection of the collection phrenic, iatrogenic perforation (28%). Interventions made at surgery were: suture of the perforation or anastomotic recovery plus peritoneal cleansing and drainage in 36% of cases, peritoneal cleansing and drainage in 36%. There were postoperative complications in five patients. The mortality rate was 4%.

CONCLUSION

Postoperative peritonitis are rare in our service. When they occur their rate of morbidity and mortality are high.

Frequencies and ethnic distribution of ABO and Rh(D) blood groups in Mauritania: results of first nationwide study

There is no data available on the ABO/Rh(D) frequencies in the Mauritanian population. We retrospectively analysed records of a 5-year database that contained ABO/Rh phenotype and ethnic origin of 10 116 volunteers giving blood at the national blood transfusion centre to derive the frequencies of ABO/Rh(D) groups in the Mauritanian population. The two race categories in the country and their sub-ethnic groups: the Moors (whites and black) and the black Africans (Pulhars, Soninkes and Wolof) were included in this study. Globally, group O had the highest frequency (49.10%) followed by A (28.28%), B (18.56%) and AB (4.05%). This order more common in North African populations was found in four of the five ethnic groups composing our population. Allele frequencies were, respectively, 70.20%, 17.74% and 12.04% giving the same order of O > A > B. We observed no significant variation in these frequencies between the different ethnic groups. Rhesus study showed that with a percentage of 94.23% Rh(D) positive is by far the most prevalent, while Rh(D) negative is present only in 5.77% of the total population. This frequency distribution supports the mixed-race composition of the Mauritanian population.

[Lymphocytic meningitis in Bamako, Mali]

We conducted a prospective survey from January 2001 to March 2002. Our objective was to study etiologic, clinic, and prognostic aspect of lymphocytic meningitis in hospital of Point G to Bamako. We included 35 patients with 25 male (71. 4%) and 10 female (28. 6%), sex - ratio (M / F) equal 2. 5. The median age was of 35 ± 25.4 years (range, 16 - 66 years). HIV serology was positive 26 cases (83. 9%). Clinical presentations were different. We observed 15 cases of encephalitis, 12 cases of meningoencephalitis, 2 cases of meningitis and 6 cases of febrile syndrome. Mean duration of hospitalization was 32. 6 ± 68 days. Mean of lymphocyte was 85.3 ± 25.9% among leukocytes in cerebrospinal fluid of 31 patients. Analysis of cerebrospinal fluid (CSF) identified in 9 cases Cryptococcocus neoformans. In 16 cases etiology was determination based on indirect arguments. In 9 cases viral meningoencephalitis diagnosis was made by exodiagnosis. It concerned 2 cases of TB meningitis, 1 case of cerebral toxoplasmosis, 1 case of decapitate bacterial meningitis and 1 case of cerebral tumor. Malaria thick smear permits to diagnosticate 1 case of cerebral malaria and 1 case of uncomplicated malaria. There are still 10 cases in which the cause remained unknown during study. HIV infection provides principally lymphocytic meningitis. Co morbidity with HIV is associated to lethality at 75%. But no statistical difference with patients without HIV (p = 0.52). Our work puts in exergue all problematic and hold correct of lymphocytic meningitis in our country.

Determination of levofloxacin in plasma, bronchoalveolar lavage and bone tissues by high-performance liquid chromatography with ultraviolet detection using a fully automated extraction method

The aim of this study was to develop a specific and sensitive high-performance liquid chromatographic (HPLC) assay for the determination of levofloxacin in human plasma, bronchoalveolar lavage and bone tissues. The sample extraction was based on a fully automated liquid-solid extraction with an OASIS cartridge. The method used ultraviolet detection set at a wavelength of 299 nm and a separation with a Supelcosil ABZ+ column. The assay has been found linear over the concentration range 0.25-25 microg/ml for levofloxacin in plasma, 1-6 microg/ml in bronchoalveolar lavage and 0.5-10 microg/g for bone tissues and it provided good validation data for accuracy and precision. The assay will be applied to determine the penetration of levofloxacin in human bronchoalveolar lavage (BAL) and bone tissues during pharmacokinetic steady state.

High-performance liquid chromatographic separation of fluoroquinolone enantiomers: a review

Fluoroquinolones are antibacterial agents widely used clinically. In recent years, there has been an important development of new derivatives, and more than 7000 analogues have been described today. Different fluoroquinolones (FQ) have one or two chiral centers in their chemical structure and are available as racemates, diastereoisomers, or pure enantiomers. The clinical and pharmaceutical uses of these compounds need effective analytical procedures for quality control and pharmacodynamic and pharmacokinetic studies. This review article focuses on the high-performance liquid chromatographic separation of fluoroquinolone stereoisomers by the use of derivatization methods and ligand exchange (LE) or chiral liquid chromatography.

Simultaneous determination of ritonavir and saquinavir, two human immunodeficiency virus protease inhibitors, in human serum by high-performance liquid chromatography

The aim of this study was to describe an high-performance liquid chromatographic assay for the simultaneous determination of two HIV protease inhibitors, saquinavir and ritonavir, in human serum. The method involved extraction of ritonavir and saquinavir from serum with the aid of solid-phase extraction C18 cartridges followed by high-performance liquid chromatography with a C8 column and ultraviolet detection set at a wavelength of 240 nm. The assay was linear and has been validated over the concentrations range of 0.5-32 microg/ml for ritonavir and 0.075-4.8 microg/ml for saquinavir, from 600 microl serum extracted. In future, the assay will be used to support human population pharmacokinetic studies, and therapeutic drug monitoring for ritonavir and saquinavir.

A new extrapolation method from animals to man: application to a metabolized compound, mofarotene

Allometric scaling (a technique which uses data obtained in laboratory animals to predict human pharmacokinetics) works well for drugs that are cleared intact, but is less successful with extensively metabolised compounds. This paper describes a new method to improve the accuracy of such projections, by integrating metabolic data obtained in vitro (e.g. with liver microsomes or hepatocytes) into these calculations. The approach was used prospectively, to predict the clearance of mofarotene (Ro 40-8757) in humans from in vivo kinetic data obtained in mouse, rat and dog. This compound was selected to illustrate this approach because it is exclusively eliminated through metabolism. Without the metabolic correction or using empirical correcting factors, the values predicted for man were 2.7 and 0.6 ml/min/kg. This fell outside the range subsequently obtained in healthy volunteers dosed orally with 300 mg of mofarotene (7.5 +/- 4.0 ml/min/kg, n = 12). However, inclusion of the microsomal or hepatocyte data gave values of 5.1 and 4.2 ml/min/kg, respectively, illustrating that the integration of in vitro metabolic data improves the accuracy of kinetic extrapolations. In contrast to the existing empirical techniques, this approach offers a rational basis to predict clearance of metabolized compounds in human.

In vivo and in vitro kinetics of mofarotene in mouse, rat, dog and man

The pharmacokinetics of mofarotene were investigated in mice, rats and dogs following single intravenous and oral administrations. Healthy volunteers were also given a single oral dose of 300 mg mofarotene. The data indicate a similar disposition for mofarotene in all species studied: low clearance consistent with a high bioavailability following oral dosing, and large volume of distribution indicating an extensive tissue uptake. Also in vitro in liver microsomes, the values for intrinsic clearance were in all species within a 2-fold range. The dog, however, tended to exhibit, both in vitro and in vivo, the lowest clearance. Although (due to the lack of protein binding data) a direct prediction of the in vivo clearance from in vitro data was not possible, the experiments with liver microsomes did provide a clear insight into the rate of elimination of mofarotene in vivo in the different species studied including man.

Use of dabsylation, column switching and chiral separation for the determination of a renin inhibitor in rat, marmoset and human plasma

A high-performance liquid chromatographic method with column switching was developed for the determination of the renin inhibitor Ro 42-5892/001, (S)-alpha-[(S)-alpha-[(tert.-butylsulphonyl)methyl]hydrocinnama mido]-N- [(1S,2R,3S)-1-(cyclohexylmethyl)-3-cylcopropyl-2, 3-dihydroxypropyl]imidazole-4-propionamide methanesulphonate (1:1), in rat, marmoset and human plasma, using a Nucleosil C8 120 (3 microns) stationary phase. Since the analyte and the internal standard are optical isomers, beta-cyclodextrin was used as a mobile phase constituent for their chiral separation. The method took advantage of the characteristics of dabsyl chloride derivatives, namely sensitivity, specificity and, particularly, stability, providing a quantification limit of 5 ng/ml. The accuracy (range of inaccuracy 1-13%) and the inter-assay precision (coefficient of variation range 1.8-9.1%) were acceptable. The method was successfully applied to toxicokinetic studies in rats and marmosets.

Ion exchange paper adsorption and thin-layer chromatography for detection of chloroquine in urine for the study of chemosensitivity of Plasmodium falciparum

With a view to determining the chemosensitivity of Plasmodium falciparum to chloroquine, two qualitative tests for the detection of this antimalarial agent in urine were compared in Central African schoolchildren: the test of Dill and Glazko and a thin-layer chromatography technique involving ion exchange and extraction. Results obtained with 149 subjects showed the marked superiority in specificity and sensitivity of the chromatography test. This is of particular interest when selecting subjects before a therapeutic trial is undertaken. After administration of a single dose of chloroquine (10 mg kg-1) to 14 schoolchildren, both urinary detection tests gave positive results at 24 and 48 hours. However, on day 7 all results with the chromatography test were positive, while 57% of false negatives were recorded by the Dill and Glazko test.

Comparative study of the pharmacokinetics of zuclopenthixol decanoate and fluphenazine decanoate

Seventeen outpatients were treated with depot neuroleptics, zuclopenthixol decanoate in Viscoleo or fluphenazine decanoate in sesame oil, with dosage intervals of 3 weeks. During the 4th, 6th, and 8th dosage interval blood samples were drawn in oxalated tubes. Plasma concentrations of the active neuroleptic drugs, zuclopenthixol and fluphenazine, were determined by high performance liquid chromatography. The concentrations indicated some interindividual as well as intraindividual variations. For zuclopenthixol the maximum concentration was most often seen at day 7 after injection, whereas the kinetics of the fluphenazine concentrations was more variable. There was an indication of more fluctuation in the 4th dosage interval than in the 8th dosage interval, possibly due to the fact that steady state has not yet been achieved at the 4th dosage interval.

Plasma quantification of quazepam and its 2-oxo and N-desmethyl metabolites by capillary gas chromatography

The authors have developed a gas chromatographic method for the simultaneous quantification of quazepam in plasma and its two main metabolites, 2-oxoquazepam and N-desmethylquazepam. This method involves an extraction from plasma using butyl acetate, and an analysis by electron-capture detection on a CP-Sil 5 WSCOT capillary column. Intra- and inter-day precision and accuracy were better than 10% for each of these three compounds, even near their detection limit estimated at 0.2 ng/ml. Linearity proved satisfactory between 0.2 and 60-70 ng/ml. For endogenous plasma components, adequate specificity was achieved. Despite some inconveniences, a long analysis time, a progressive saturation of the column owing to a low oven temperature, and a relatively short life-span of the CP-Sil 5 columns, this method was the only one available in the literature for the quantification of quazepam and its metabolites from the same plasma sample. It was successfully applied to phase I studies in healthy volunteers.

Blood and plasma kinetics of cis(Z)-clopenthixol and fluphenazine in psychiatric patients after intramuscular injection of their decanoic esters

Whole blood and plasma concentrations of active neuroleptic drugs were measured in eight schizophrenic outpatients who had received cis(Z)-clopenthixol decanoate in Viscoleo or fluphenazine decanoate in sesame oil by intramuscular injection. Whole blood and plasma concentrations were very similar, though there was a slight tendency for blood concentrations to be higher than plasma concentrations. Maximum concentrations appeared at 1 week after administration of cis(Z)-clopenthixol decanoate, whereas the highest concentrations after fluphenazine decanoate were seen at the end of the 3-week dosage interval. Some between-individual variation and a limited within-individual variation was seen.