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1.
JAC Antimicrob Resist ; 3(2): dlab050, 2021 Jun.
Article in English | MEDLINE | ID: mdl-34223118

ABSTRACT

BACKGROUND: HIV drug resistance (HIV-DR) is rising in sub-Saharan Africa in both ART-naive and ART-experienced patients. OBJECTIVES: To estimate the level of acquired DR (ADR) and pre-treatment DR (PDR) across selected urban and rural sites in Southern Africa, in Mozambique. METHODS: We conducted two cross-sectional surveys among adult HIV patients (October 2017-18) assessing ADR and PDR. In the (ADR) survey, those on NNRTI-based first-line ART for ≥6 months were recruited (three sites). In the PDR survey, those ART-naive or experienced with ≥3 months of treatment interruption prior were enrolled (eight sites). RESULTS: Among 1113 ADR survey participants 83% were receiving tenofovir (TDF)/lamivudine (3TC)/efavirenz (EFV). The median time on ART was 4.5 years (Maputo) and 3.2 years (Tete), 8.3% (95% CI 6.2%-10.6%, Maputo) and 15.5% (Tete) had a VL ≥ 1000 copies/mL, among whom 66% and 76.4% had NNRTI+NRTI resistance, and 52.8% and 66.7% had 3TC+TDF-DR. Among those on TDF regimens, 31.1% (Maputo) and 42.2% (Tete) were still TDF susceptible, whereas 24.4% and 11.5% had TDF+zidovudine (ZDV)-DR. Among those on ZDV regimens, 25% and 54.5% had TDF+ZDV-DR. The PDR survey included 735 participants: NNRTI-PDR was 16.8% (12.0-22.6) (Maputo) and 31.2% (26.2-36.6) (Tete), with a higher proportion (≥50%) among those previously on ART affected by PDR. CONCLUSIONS: In Mozambique, viral failure was driven by NNRTI and NRTI resistance, with NRTI DR affecting backbone options. NNRTI-PDR levels surpassed the WHO 10% 'alert' threshold. Replacing NNRTI first-line drugs is urgent, as is frequent viral load monitoring and resistance surveillance. Changing NRTI backbones when switching to second-line regimens may need reconsideration.

2.
Trop Med Int Health ; 23(10): 1075-1083, 2018 10.
Article in English | MEDLINE | ID: mdl-30058269

ABSTRACT

OBJECTIVES: The number of patients on second-line antiretroviral therapy is growing, but data on HIV drug resistance patterns at failure in resource-constrained settings are scarce. We aimed to describe drug resistance and investigate the factors associated with extensive resistance to nucleoside/nucleotide reverse transcriptase inhibitors (NRTI), in patients failing second-line therapy in the HIV outpatient clinic at Arua Regional Referral Hospital, Uganda. METHODS: We included patients who failed on second-line therapy (two consecutive viral loads ≥1000 copies/mm3 by SAMBA-1 point-of-care test) and who had a drug resistance test performed between September 2014 and March 2017. Logistic regression was used to investigate factors associated with NRTI genotypic sensitivity score (GSS) ≤1. RESULTS: Seventy-eight patients were included: 42% female, median age 31 years and median time of 29 months on second-line therapy. Among 70 cases with drug resistance test results, predominant subtypes were A (47%) and D (40%); 18.5% had ≥1 major protease inhibitor mutation; 82.8% had ≥1 NRTI mutation and 38.5% had extensive NRTI resistance (NRTI GSS ≤1). A nadir CD4 count ≤100/ml was associated with NRTI GSS ≤1 (OR 4.2, 95% CI [1.3-15.1]). Thirty (42.8%) patients were switched to third-line therapy, composed of integrase inhibitor and protease inhibitor (60% darunavir/r) +/- NRTI. A follow-up viral load was available for 19 third-line patients at 12 months: 84.2% were undetectable. CONCLUSIONS: Our study highlights the need for access to drug resistance tests to avoid unnecessary switches to third-line therapy, but also for access to third-line drugs, in particular integrase inhibitors. Low nadir CD4 count might be an indicator of third-line drug requirement for patients failing second-line therapy.


Subject(s)
Anti-HIV Agents/therapeutic use , Antiretroviral Therapy, Highly Active/methods , Drug Resistance, Multiple, Viral , HIV Infections/drug therapy , Adult , Female , HIV Infections/virology , Humans , Logistic Models , Male , Medication Adherence , Reverse Transcriptase Inhibitors/therapeutic use , Risk Factors , Uganda , Viral Load/drug effects , Young Adult
4.
Anaesth Intensive Care ; 34(6): 753-7, 2006 Dec.
Article in English | MEDLINE | ID: mdl-17183893

ABSTRACT

The purpose was to identify how the quality of anaesthesia research has improved from articles published in Anaesthesia and Intensive Care over 25 years. Original papers were included during the periods 1974-1978 and 2000-2004. Each article was classified according to principal research designs and the two five-year periods were compared. All interventional trials were evaluated according to the following a priori criteria: author number; ethics approval; informed consent; competing financial interest; eligibility criteria; sample size calculation; method of randomization; patients accounted for; blind assessment of outcome; adverse outcomes; statistical method stated; type I error; type II error; and anaesthetic department of origin. Comparisons of above criteria were made between the two groups using chi-square test or Fischer's exact test. Two-hundred-and-ninety-two articles were reviewed in 1974-1978 and 529 articles were reviewed in 2000-2004. Animal/laboratory articles decreased from 17.47% to 12.28% (P=0.05). Review articles decreased from 34.35% to 10.4% (P<0.0001). Descriptive trials increased from 28.4% to 52.72% (P<0.0001). Interventional trials increased from 18.84% to 22.31% (P=0.269). Uncontrolled clinical trials decreased from 27.27% to 12.71%, non-randomized controlled trials decreased from 50.91% to 7.63%, and randomized controlled trials increased from 21.82% to 79.66% (P<0.0001). All interventional trials criteria improved and were statistically significant except competing financial interest, method of randomization, patients accounted for; and type II error The quality of anaesthetic research has improved in Anaesthesia and Intensive Care over the past 30 years. However; there is still room for improvement.


Subject(s)
Anesthesia/statistics & numerical data , Bibliometrics , Biomedical Research/statistics & numerical data , Critical Care/statistics & numerical data , Periodicals as Topic/statistics & numerical data , Anesthesia/trends , Animals , Biomedical Research/trends , Chi-Square Distribution , Critical Care/trends , Humans , Longitudinal Studies , Periodicals as Topic/trends
5.
Clin Microbiol Infect ; 12(11): 1082-8, 2006 Nov.
Article in English | MEDLINE | ID: mdl-17002607

ABSTRACT

A randomised, double-blind, placebo-controlled study examined the safety, tolerance, immunological effect and anti-human immunodeficiency virus (HIV) activity of sub-cutaneously administered HE2000 (16alpha-bromoepiandrosterone) as monotherapy in treatment-naïve patients with HIV-1. Twenty-four patients received five sequential daily doses of 50 or 100 mg of HE2000 or placebo every 6 weeks for up to three courses, and were followed thereafter for 3 months. HE2000 was safe, with transient injection site reactions being the main side-effect. Peripheral blood samples, collected serially, were analysed for changes in immune cell phenotypes. Significant increases were observed in the numbers of circulating dendritic cells, early activated (CD69+ CD25-) CD8 T-cells and T-NK cells after administration of 50-mg doses of HE2000 (p < 0.05). Gene expression in peripheral blood mononuclear cells was analysed by real-time RT-PCR. Before treatment, HIV-1-infected patients had significantly elevated transcripts for a number of inflammatory mediators (p < 0.012). After 50 mg or 100 mg HE2000, but not after placebo, there were significant sustained decreases in IL-1beta, TNF-alpha, IL-6 and Cox-2 transcripts (p < 0.05). There were no significant differences in CD4 cell numbers, although patients receiving 50-mg doses demonstrated a significant decrease in viral load (- 0.6 log; p < 0.01). Anti-HIV-1 T-cell responses were analysed serially using GAG-peptides to stimulate cytoplasmic IFN-gamma responses. After three courses, the 50-mg dose group demonstrated a significant increase in CD8 T-cell response against two distinct GAG peptide pools (p < 0.03). These findings suggest that immune-based therapies may be able to impact viral load by decreasing inflammation and/or stimulating CD8 T-cells.


Subject(s)
Androsterone/analogs & derivatives , Anti-HIV Agents/therapeutic use , HIV Infections/drug therapy , HIV-1 , Adult , Androsterone/administration & dosage , Androsterone/therapeutic use , Anti-HIV Agents/administration & dosage , Antigens, CD/analysis , Antigens, Differentiation, T-Lymphocyte/analysis , Cell Count , Cyclooxygenase 2/genetics , Cyclooxygenase 2/metabolism , Dendritic Cells/cytology , Double-Blind Method , Female , Flow Cytometry , HIV Infections/immunology , HIV Infections/virology , Humans , Injections, Subcutaneous , Interleukin-1/genetics , Interleukin-1/metabolism , Interleukin-2 Receptor alpha Subunit/analysis , Interleukin-6/genetics , Interleukin-6/metabolism , Killer Cells, Natural/immunology , Lectins, C-Type , Leukocyte Count , Leukocytes, Mononuclear/metabolism , Male , Membrane Proteins/genetics , Membrane Proteins/metabolism , RNA, Messenger/analysis , Reagent Kits, Diagnostic , T-Lymphocytes/immunology , Treatment Outcome , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/metabolism , Viral Load
6.
Eur Respir J ; 21(1): 116-22, 2003 Jan.
Article in English | MEDLINE | ID: mdl-12570119

ABSTRACT

The purpose of this study was to evaluate the cost of illness of moderate-to-severe atopic asthma and/or seasonal allergic rhinitis (SAR) in Germany from the perspective of third-party payers (TPP) and patients. Five-hundred patients (276 children/adolescents) with moderate-to-severe asthma and/or SAR were included in this cross-sectional study. Information was collected using a specific patient questionnaire and the abstraction of patient records. Overall, annual costs per patient increased with the severity of atopic asthma and if it was associated with SAR. The average annual cost of SAR was Euro1,089 per child/adolescent and Euro1,543 per adult. Annual costs of severe asthma plus SAR increased to Euro7,928 per child/adolescent and to Euro9,287 per adult. For TPPs, the main cost drivers were medication, hospitalisation, and rehabilitation. The most significant costs for patients were household modifications. For children/adolescents, 60-78% of the expenditures were direct costs, while in adults, 58% of expenditures were indirect costs. It was also observed that patients with moderate and severe asthma used inhaled corticosteroids less frequently than recommended by treatment guidelines. In summary, the total cost for patients increases with the severity of atopic asthma and/or seasonal allergic rhinitis and indirect costs represent a large proportion of the total cost.


Subject(s)
Asthma/economics , Cost of Illness , Health Care Costs , Rhinitis, Allergic, Seasonal/economics , Adolescent , Adult , Aged , Asthma/drug therapy , Child , Cross-Sectional Studies , Drug Costs , Female , Germany , Hospital Costs , Humans , Hypersensitivity, Immediate/drug therapy , Hypersensitivity, Immediate/economics , Insurance, Health, Reimbursement , Male , Middle Aged , Retrospective Studies , Rhinitis, Allergic, Seasonal/drug therapy , Severity of Illness Index
7.
J Virol ; 75(18): 8842-7, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11507229

ABSTRACT

It has been hypothesized that human immunodeficiency virus type 1 (HIV-1) evolves toward increased cytopathicity in conjunction with disease progression in infected patients. A viral property known to evolve in some but not all patients is coreceptor utilization, and it has been shown that a switch in coreceptor utilization is sufficient for the development of increased cytopathicity. To test the hypothesis that the evolution of other viral properties also contributes to accelerating cytopathicity in vivo, we used human lymphoid tissue explants to assay the cytopathicity of a panel of primary HIV-1 isolates derived from various stages of disease characterized by the presence or absence of changes in coreceptor preference. We found no evidence of coreceptor-independent increases in cytopathicity in isolates obtained either before coreceptor preference changes or from patients who progressed to AIDS despite an absence of coreceptor evolution. Instead, the cytopathicity of all HIV-1 isolates was determined solely by their coreceptor utilization. These results argue that HIV-1 does not evolve toward increased cytopathicity independently of changes in coreceptor utilization.


Subject(s)
HIV Infections/virology , HIV-1/pathogenicity , CD4-Positive T-Lymphocytes/immunology , Cytopathogenic Effect, Viral , HIV Infections/immunology , HIV Infections/physiopathology , HIV-1/immunology , HIV-1/isolation & purification , Humans , Lymphocyte Depletion , Receptors, CCR5/immunology , Receptors, CXCR4/immunology
8.
Anaesth Intensive Care ; 29(4): 388-92, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11512650

ABSTRACT

Unselected preoperative coagulation testing is known to have low positive yield. However, no study has specifically evaluated neurosurgical patients. A retrospective study of 1211 patients having neurosurgery over a one-year period was therefore conducted. Preoperative test results (activated partial thromboplastin time [aPTT], prothrombin time [PT] and platelet count) and historical factors indicating a potential bleeding tendency were recorded. Abnormality was defined as a test result outside the normal range for our laboratory. Seventeen per cent of all test results were abnormal. However, if abnormality was redefined as a test result indicating potential bleeding tendency (low platelet count, prolonged aPTT and/or PT), only 7.2% of results were abnormal. Many patients had factors on history indicating a potential bleeding tendency, but only a prolonged aPTT, cranial surgery and the use of anti-hypertensive and anaesthetic drugs preoperatively predicted postoperative bleeding. Prolonged aPTT was predictable on history in most patients. We conclude that routine screening of all preoperative neurosurgical patients in our hospital is unnecessary.


Subject(s)
Blood Coagulation Tests , Neurosurgery , Preoperative Care , Blood Coagulation/drug effects , Female , Hemorrhagic Disorders/diagnosis , Humans , Male , Middle Aged , Partial Thromboplastin Time , Platelet Count , Prothrombin Time , Retrospective Studies
9.
J Virol ; 74(20): 9594-600, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11000231

ABSTRACT

Epidemiological studies have shown that human immunodeficiency virus type 2 (HIV-2) is markedly less pathogenic than HIV-1 in vivo. Individuals infected with HIV-2 exhibit a remarkably slow rate of disease development, and these clinical properties have been attributed presumptively to an "attenuated" phenotype of HIV-2 itself. Here, we investigated the impact of coreceptor usage on the cytopathicity of HIV-2 and compared its pathogenic potential with that of HIV-1 in a unique human lymphoid histoculture model. We found that HIV-2 strains, as well as closely related simian immunodeficiency viruses (SIV), displayed mildly or highly aggressive cytopathic phenotypes depending on their abilities to use the coreceptor CCR5 or CXCR4, respectively. A side-by-side comparison of primary X4 HIV-1 and HIV-2 strains revealed similar, high degrees of cytopathicity induced by both HIV types. Furthermore, we found that HIV-2 coreceptor specificity for CCR5 and CXCR4 determined the target cell population for T-cell depletion in lymphoid tissue. Finally, utilization of the alternate coreceptors BOB and Bonzo did not significantly increase the cytopathic properties of HIV-2. These findings demonstrate that coreceptor preference is a key regulator of target cell specificity and the cytopathic potential of HIV-2, with indistinguishable rules compared with HIV-1. Moreover, HIV-2 strains are not characterized by an intrinsically lower cytopathicity than HIV-1 strains. Therefore, direct cytopathic potential per se does not explain the unique behavior of HIV-2 in people, highlighting that other unknown factors need to be elucidated as the basis for their lesser virulence in vivo.


Subject(s)
HIV-1/pathogenicity , HIV-2/pathogenicity , Lymphoid Tissue/virology , Receptors, CCR5/physiology , Receptors, CXCR4/physiology , CD4-Positive T-Lymphocytes/physiology , Humans , Virulence
10.
J Virol ; 74(11): 5347-51, 2000 Jun.
Article in English | MEDLINE | ID: mdl-10799612

ABSTRACT

The present study sought to determine how usage of coreceptors by human immunodeficiency virus type 1 dictates cell tropism and depletion of CD4(+) T cells in human lymphoid tissues cultured ex vivo. We found that coreceptor preferences control the marked, preferential depletion of coreceptor-expressing CD4(+) lymphocytes. In addition, there was a strong, but not absolute, preference shown by CXCR4-using strains for lymphocytes and by CCR5-using strains for macrophages.


Subject(s)
CD4-Positive T-Lymphocytes/metabolism , HIV-1/metabolism , Lymphocyte Depletion , Receptors, CCR5/metabolism , Receptors, CXCR4/metabolism , CD4-Positive T-Lymphocytes/virology , HIV-1/physiology , Humans , Lymphoid Tissue/cytology
11.
J Virol ; 74(1): 184-92, 2000 Jan.
Article in English | MEDLINE | ID: mdl-10590105

ABSTRACT

The chemokine receptors CCR5 and CXCR4 function as the principal coreceptors for human immunodeficiency virus type 1 (HIV-1). Coreceptor function has also been demonstrated for a variety of related receptors in vitro. The relative contributions of CCR5, CXCR4, and other putative coreceptors to HIV-1 disease in vivo have yet to be defined. In this study, we used sequential primary isolates and recombinant strains of HIV-1 to demonstrate that CXCR4-using (X4) viruses emerging in association with disease progression are highly pathogenic in ex vivo lymphoid tissues compared to CXCR4-independent viruses. Furthermore, synthetic receptor antagonists that specifically block CXCR4-mediated entry dramatically suppressed the depletion of CD4(+) T cells by recombinant and clinically derived X4 HIV-1 isolates. Moreover, in vitro specificity for the additional coreceptors CCR3, CCR8, BOB, and Bonzo did not augment cytopathicity or diminish sensitivity toward CXCR4 antagonists in lymphoid tissues. These data provide strong evidence to support the concept that adaptation to CXCR4 specificity in vivo accelerates HIV-1 disease progression. Thus, therapeutic intervention targeting the interaction of HIV-1 gp120 with CXCR4 may be highly valuable for suppressing the pathogenic effects of late-stage viruses.


Subject(s)
HIV-1/physiology , Membrane Fusion/physiology , Receptors, CXCR4/physiology , Animals , CD4-Positive T-Lymphocytes/cytology , COS Cells , Cell Line , HIV-1/pathogenicity , Humans , Lymphocyte Depletion , Virulence , Virus Replication
12.
Gen Comp Endocrinol ; 114(1): 108-20, 1999 Apr.
Article in English | MEDLINE | ID: mdl-10094864

ABSTRACT

The Galápagos Islands are home to 11 subspecies of large terrestrial tortoises (Geochelone nigra). All Galápagos tortoises are considered endangered and approximately 12,000 animals still exist. Until now, the reproductive cycle of the Galápagos tortoise has been studied only in captive animals, and no data from free-ranging tortoises have been available. During a one-year period, blood samples were collected from male and female G. nigra living under seminatural conditions on Santa Cruz Island, Galápagos. Plasma steroid hormones were measured by radioimmunoassays (RIAs). In males, plasma testosterone and corticosterone increased a few months before the onset of the mating season. Peak levels were observed while most copulations occurred and environmental temperatures were highest. Both testosterone and corticosterone showed low levels during the cold and dry nesting season and high levels during the hot and rainy mating season. In females, testosterone and corticosterone also rose during the hot and rainy mating season. Both hormones peaked during the second half of the mating season and decreased during the cooler dry season. Female estradiol levels increased at the onset of the mating season, reaching the highest level at the peak of the mating season, which coincided with the highest annual temperatures measured. Estradiol slowly decreased within the next months and rapidly dropped at the onset of the nesting season when temperatures decreased. Progesterone levels were high close to the time of ovulation and showed clearly elevated levels at the beginning of the nesting season after some females had laid their first clutch. Progesterone decreased during the nesting season, when ambient temperatures began to decrease, and reached minimal levels in the postbreeding period shortly before the onset of the next mating season. There were significant annual variations in plasma testosterone in both males and females. Plasma corticosterone was generally higher in males than in females and varied throughout the year in both sexes.


Subject(s)
Gonadal Steroid Hormones/blood , Reproduction , Turtles/physiology , Animals , Corticosterone/blood , Ecuador , Female , Male , Radioimmunoassay/veterinary , Seasons , Testosterone/blood , Turtles/blood
13.
Proc Natl Acad Sci U S A ; 96(2): 663-8, 1999 Jan 19.
Article in English | MEDLINE | ID: mdl-9892690

ABSTRACT

The human chemokine receptors CCR5 and CXCR4 have emerged as the predominant cofactors, along with CD4, for cellular entry of HIV-1 in vivo whereas the contribution of other chemokine receptors to HIV disease has not been yet determined. CCR5-specific (R5) viruses predominate during primary HIV-1 infection whereas viruses with specificity for CXCR4 (R5/X4 or X4 viruses) often emerge in late stages of HIV disease. The evolution of X4 viruses is associated with a rapid decline in CD4+ T cells, although a causative relationship between viral tropism and CD4+ T cell depletion has not yet been proven. To rigorously test this relationship, we assessed CD4+ T cell depletion in suspensions of human peripheral blood mononuclear cells and in explants of human lymphoid tissue on exposure to paired viruses that are genetically identical (isogenic) except for select envelope determinants specifying reciprocal tropism for CXCR4 or CCR5. In both systems, X4 HIV-1 massively depleted CD4+ lymphocytes whereas matched R5 viruses depleted such cells only mildly despite comparable viral replication kinetics. These findings demonstrate that the coreceptor specificities of HIV-1 are a causal factor in CD4+ T cell depletion ex vivo and strongly support the hypothesis that the evolution of viral envelope leading to usage of CXCR4 in vivo accelerates loss of CD4+ T cells, causing immunodeficiency.


Subject(s)
CD4-Positive T-Lymphocytes/immunology , HIV Infections/immunology , HIV-1/genetics , Receptors, CXCR4/metabolism , Animals , CD4-CD8 Ratio , COS Cells , Cell Survival/immunology , Humans , Palatine Tonsil/immunology , Receptors, CCR5/metabolism , Spleen/immunology , Transfection/genetics , Virus Replication/genetics
14.
Eur J Biochem ; 247(3): 843-51, 1997 Aug 01.
Article in English | MEDLINE | ID: mdl-9288906

ABSTRACT

Human immunodeficiency virus (HIV) Nef functions are thought to be mediated via interactions with cellular proteins. Utilizing zone velocity sedimentation in glycerol gradients we found that recombinant HIV-1 Nef non-covalently associates with actin forming a high-molecular-mass complex of 150-300 kDa. This Nef/actin complex was present in human B and T lymphocytes but not in insect cells and was dependent on the N-terminal myristoylation of Nef, whereas the SH3-binding proline motif of Nef was not involved. Despite being myristoylated, HIV-2 Nef did not associate with actin. This might reflect differences in the subcellular localization of Nef since cell-fractionation experiments revealed that HIV-1 Nef was virtually exclusively localized in the cytoskeletal (detergent-insoluble) fraction whereas HIV-2 Nef had significantly reduced affinity for the cytoskeleton. Colocalization experiments in HIV-1-infected CD4+ fibroblasts revealed that Nef/actin complexes may also exist in HIV-infected cells. This novel interaction of HIV-1 Nef with actin provides insight into the association of Nef with cellular structures and reveals general differences in the interactions of the Nef proteins from HIV-1 and HIV-2.


Subject(s)
Actins/metabolism , Gene Products, nef/metabolism , HIV-1/metabolism , HIV-2/metabolism , Subcellular Fractions/metabolism , Animals , Cell Line , Gene Products, nef/chemistry , Molecular Weight , Myristic Acid , Myristic Acids/metabolism , Protein Binding , Recombinant Proteins/chemistry , Recombinant Proteins/metabolism , Spodoptera , T-Lymphocytes/metabolism , nef Gene Products, Human Immunodeficiency Virus
15.
Article in German | MEDLINE | ID: mdl-9101769

ABSTRACT

We investigated 2007 patients over a period of 2 years. Of this group we found 25.9% of patients were over 70 years of age. Of the entire pool 97 patients had renal failure, forcing us to perform continuous venovenous hemofiltration (CVVH). Indications for doing CVVH were identical in young and old patients. Of the filtrated patients 29 died. Only 44.8% of the non-survivors belonged to the group of elderly patients. We conclude from our investigation that there is no indication that older patients have worse prognoses than younger patients in the case of renal failure.


Subject(s)
Acute Kidney Injury/therapy , Cardiovascular Diseases/surgery , Hemofiltration , Postoperative Complications/therapy , Acute Kidney Injury/mortality , Aged , Cardiovascular Diseases/mortality , Female , Geriatric Assessment , Humans , Male , Postoperative Complications/mortality , Risk Factors , Survival Rate
16.
J Clin Monit ; 11(3): 168-74, 1995 May.
Article in English | MEDLINE | ID: mdl-7623056

ABSTRACT

OBJECTIVE: The objective of our study was to establish the refractive indices and the virial coefficients of the volatile anesthetic vapors. These indices and coefficients will allow refractometry to be used by manufacturers to produce accurate calibration, without requiring expensive high-precision calibration gases. METHODS: We used a precision refractometer to measure the refractive indices for five volatile anesthetic vapors. We prepared our calibration gases by mixing a gravimetrically calibrated amount of liquid agent with a constant gas flow. RESULTS: The refractive indices for the volatile anesthetic vapors are 1,603.2 for halothane, 1,540.4 for enflurane, 1,563.3 for isoflurane, 1,538.3 for sevoflurane, and 1,211.7 for desflurane. The maximum theoretical error in our measurements, due to all sensors and all uncertainty in our measurement of apparatus and physical constants, is +/- 0.56% of the reading (+/- 0.70% for desflurane). CONCLUSIONS: If refractometry replaced calibration gases in cylinders, as a calibration standard, manufacturers might avoid errors that now occur because calibration gases manufactured by numerous companies seem to differ. We propose that our values serve as an interim database.


Subject(s)
Anesthesia, Inhalation/instrumentation , Anesthetics/analysis , Environmental Monitoring/instrumentation , Nebulizers and Vaporizers , Refractometry , Calibration , Gases/analysis , Humans , Refractometry/instrumentation , Refractometry/methods
17.
Bull Assoc Anat (Nancy) ; 73(221): 21-8, 1989 Jun.
Article in French | MEDLINE | ID: mdl-2804384

ABSTRACT

A scanning electron microscopic study of the coxo-femoral articular cartilage was performed in ten human fetuses aged from 15 to 40 weeks. An irregular surface was observed at the level of both femoral head and acetabulum. These surface irregularities are modified during development.


Subject(s)
Acetabulum/ultrastructure , Cartilage, Articular/ultrastructure , Femur Head/ultrastructure , Fetus/anatomy & histology , Gestational Age , Humans , Microscopy, Electron, Scanning
19.
Bull Assoc Anat (Nancy) ; 71(214): 15-21, 1987 Sep.
Article in English | MEDLINE | ID: mdl-3502777

ABSTRACT

A scanning electron microscopic study of the development of the human quadriceps was performed in 30 fetuses ranging from 6 to 40 weeks gestation. The results clearly illustrate the hyperplastic phase of myogenesis, showing the differentiation, multiplication and fusion of the myoblasts and the subsequent formation of different generations of myotubes. The myoblasts decrease relatively in number within the developing quadriceps until the 19th week of gestation, and remain afterwards as quiescent satellite cells. The maturation of the myotubes to myofibers and the metabolic differentiation of the fibers are not accompanied by significant changes in their external form in terms of scanning electron microscopy. The hypertrophic phase of myogenesis and general fetal growth can be followed with scanning electron microscopy by the increase in size of the fibers or bundles of fibers, as well as by the differentiation of the connective tissue components of the muscle.


Subject(s)
Muscles/embryology , Embryonic and Fetal Development , Fetus , Gestational Age , Humans , Mesoderm/cytology , Mesoderm/ultrastructure , Microscopy, Electron, Scanning , Muscles/cytology , Muscles/ultrastructure , Thigh
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