Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 23
Filter
1.
Article in English | MEDLINE | ID: mdl-38288851

ABSTRACT

BACKGROUND: The aim was to evaluate the frequency, clinicopathological features, and HPV status of oropharyngeal squamous cell carcinoma (OP-SCC) and benign HPV-related epithelial lesions of the oropharynx over the last 25 years. Moreover, a literature review was performed to investigate HPV frequency in OP-SCC samples diagnosed in Brazilian Centers. MATERIAL AND METHODS: A cross-sectional study analyzed OP-SCC, squamous papilloma, verruca vulgaris, and condyloma accuminatum, diagnosed from 1997 to 2021. HPV status of OP-SCC was determined by immunohistochemistry and "in situ" hybridization. Bivariate statistics were performed (p≤0.05). For the literature review, MEDLINE/PubMed, Web of Science, EMBASE, and Scopus were searched. Two independent reviewers assessed the studies for eligibility. RESULTS: Cross-sectional: 211 OP-SCC (63.0%) and 124 benign lesions (37.0%) were included. OP-SCC frequency increased gradually over time, whereas benign lesions had steady trends. OP-SCC affected more males (n= 171; 81.0%), though the relative frequency in females rose over time. Smoking (n= 127; 60.2%) was common in OP-SCC. Nineteen OP-SCC (13.0%) were positive for HPV. HPV-positive and HPV-negative tumors had similar clinicopathological features (p>0.05). Benign lesions predominated in middle-aged (n= 32; 26.7%) women (n= 71; 57.3%), in the soft palate (n=101; 81.5%). LITERATURE REVIEW: 32 studies were included, and in 60% of them, HPV frequency in OP-SCC was less than 25%. CONCLUSIONS: OP-SCC prevalence has been increasing, and it was mostly associated with smoking and alcohol rather than with HPV infection in Brazil. Benign lesions had a stationary frequency over the evaluated period.

2.
Int Endod J ; 54(5): 682-692, 2021 May.
Article in English | MEDLINE | ID: mdl-33300172

ABSTRACT

AIM: To characterize plasma cell subsets in chronic periapical lesions affecting permanent and primary teeth. METHODOLOGY: Only chronic periapical lesions without root canal treatment were selected. Twenty-one radicular cysts and 7 periapical granulomas affecting permanent teeth and 19 radicular cysts and 4 periapical granulomas affecting primary teeth were assessed for immunoglobulin (Ig) light chain (kappa and lambda), Ig heavy chain (IgG, IgG4, IgA, IgM and IgD) and plasma cell immunohistochemical markers (MUM1/IRF4, EMA and CD138). The data acquired were analysed by Student's t test, Mann-Whitney U, Friedman test followed by Dunn's multiple comparison test and Spearman's rank correlation. RESULTS: All cases were polyclonal (having similar kappa/lambda light chain ratios). IgG was most abundant compared to other Ig heavy chains (all, P < 0.001); like Ig light chains, but unlike IgA, there was greater expression of IgG in the primary compared to the permanent dentition, for both radicular cysts (P < 0.001) and periapical granulomas (P = 0.53). Notably, IgG4 expression was greater in the permanent than the primary dentition, for both radicular cyst (P < 0.05) and periapical granuloma (P = 0.65). IgM and IgD expression was scarce and variable, whereas plasma cell populations were detected efficiently through EMA, CD138 and MUM1/IRF4 markers, the latter being more sensitive in both dentitions. CONCLUSIONS: There were slight variations in the Ig light and heavy chain profiles in chronic periapical lesions when comparing the permanent and primary dentitions. The ability of IgG4+ plasma cell infiltration to modulate inflammatory responses in chronic periapical lesions arising from permanent as opposed to primary teeth should be considered in future studies.


Subject(s)
Periapical Granuloma , Radicular Cyst , Humans , Immunoglobulin G , Plasma Cells , Tooth, Deciduous
3.
Int Endod J ; 53(8): 1111-1119, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32344454

ABSTRACT

AIM: To investigate the presence, localization and the possible correlation of the fibroblast growth factor receptor-2 (FGFR2) with inflammatory resorption of cementum, periodontal ligament and alveolar bone during development of apical periodontitis in mice. METHODOLOGY: Apical periodontitis was experimentally induced in mandibular first molars of mice by pulp exposure to the oral environment. Healthy teeth without pulp exposure were used as controls. At 7, 21 and 42 days following pulp exposure, the animals were euthanized and the jaws were prepared for analysis under conventional and fluorescence microscopy, immunohistochemistry (FGFR2), RT-PCR (RNAm levels of RANK, RANKL, OPG, Runx2 and cathepsin K) and enzyme histochemistry (cementoclasts and osteoclasts). Statistical analysis was performed by Kruskal-Wallis tests and Dunn's post hoc tests for multiple comparisons (α = 0.05) using SAS 9.4 software. RESULTS: FGFR2-positive cells were not observed in the tissues surrounding healthy teeth but were observed in teeth with periapical lesions from seven days after root canal contamination. At days 21 and 42 after endodontic infection, the increase in periapical lesion size was accompanied by significantly enhanced expression of FGFR2 (P < 0.0001), significantly increased intensity of inflammatory cells, number of osteoclasts (P < 0.0001) and cementoclasts (P < 0.0001), and significantly enhanced RNAm levels of RANK/RANKL/OPG, Runx2 and cathepsin K compared to day 0 (P < 0.0001). At 21 and 42 days, FGFR2 was also expressed on osteoblasts, fibroblasts and inside enlarged lacunae of cementocytes along with acute and chronic inflammatory cells (macrophages, plasma cells and neutrophils). At all periods and cells, FGFR2 expression was observed in the cell membrane and cytoplasm, but not in the nucleus. CONCLUSION: In mice, FGFR2 was not expressed in tissues surrounding healthy teeth but was expressed in apical periodontitis, specifically in the membrane and cytoplasm of osteoblasts, fibroblasts, lacunae of cementocytes, and acute and chronic inflammatory cells (macrophages, plasma cells and neutrophils). Its expression was correlated with the size of the periapical lesions.


Subject(s)
Periapical Periodontitis , Receptor, Fibroblast Growth Factor, Type 2 , Animals , Dental Cementum , Mice , Osteoclasts , Root Canal Therapy
4.
Int Endod J ; 53(5): 627-635, 2020 May.
Article in English | MEDLINE | ID: mdl-31845371

ABSTRACT

AIM: To quantify M1 and M2 macrophages in radicular cysts of permanent (n = 14 cases) and primary teeth (n = 15 cases). METHODOLOGY: All patients who attended the School of Dentistry Ribeirão Preto, University of São Paulo with primary teeth or permanent molars that were scheduled for extraction and fulfilled the inclusion criteria: absence of pain; presence/absence of fistulae; extensive coronal destruction due to caries lesions without possibility of restoration; pulp necrosis; radiographically visible apical periodontitis; and no previous treatment, were selected. The radicular cysts were removed and subsequently submitted to histopathologic analysis in order to classify the type of inflammatory infiltrate. In addition, CD68 (M1+, M2+) and CD163 (M1-, M2+) markers were quantified through an immunohistochemistry analysis. The data acquired were submitted to a Mann-Whitney test, with a 5% significance level. RESULTS: The patients had a mean age of 38.6 years and 5.9 years for cysts associated with permanent and primary teeth, respectively. In the histopathological analysis, no significant difference (P = 0.87) was found between radicular cysts in primary and permanent teeth regarding the intensity of the chronic inflammatory infiltrate. A significantly greater prevalence of M2 macrophages (P < 0.05) was observed in the lesions of both permanent and primary teeth, even though both M1 and M2 macrophages were detected. No significant difference (P > 0.05) was found for M1 and M2 macrophages associated with the cysts of primary and permanent teeth. CONCLUSION: M1 and M2 macrophages were present in radicular cysts associated with primary and permanent teeth, with a greater quantity of M2 cells. The immunophenotypic quantification of M1 and M2 macrophage polarization in radicular cysts associated with primary and permanent teeth were similar.


Subject(s)
Periapical Periodontitis , Radicular Cyst , Adult , Dental Pulp Necrosis , Humans , Macrophages , Molar
5.
Oral Dis ; 19(1): 85-91, 2013 Jan.
Article in English | MEDLINE | ID: mdl-22788684

ABSTRACT

OBJECTIVE: To analyze the expression and distribution patterns of mature dendritic cells (mDCs) and immature DCs (imDCs) in radicular cysts (RCs), dentigerous cysts (DtCs), and keratocystic odontogenic tumors (KCOTs). MATERIALS AND METHODS: Forty-nine odontogenic cystic lesions (OCLs) (RCs, n = 20; DtCs, n = 15; KCOTs, n = 14) were assessed using the following markers: S100, CD1a and CD207 for imDCs; and CD83 for mDCs. RESULTS: Almost all cases were S100, CD1a, and CD207 positive, whereas 63% were CD83 positive. RCs presented greater number of immunostained cells, followed by DtCs, and KCOTs. The number of S100+ cells was greater than both CD1a+ and CD207+ cells (P < 0.001), which showed approximately similar amounts, followed by lower number of CD83+ cells (P < 0.001) in each OCL type. Different from S100+ cells, both CD1a+ and CD207+ cells on the epithelium (P < 0.05) and CD83+ cells on the capsule (P < 0.05) were preferentially observed. In RCs, significant correlation was found between the thickness epithelium with S100+ and CD1a+ cells, and between the degree of inflammation with CD83+ cells. CONCLUSIONS: Dendritic cell populations in OCLs can be phenotypically heterogeneous, and it could represent distinct lineages and/or functional stages. It is suggested that besides DC-mediated immune cell interactions, DC-mediated tissue differentiation and maintenance in OCLs should also be considered.


Subject(s)
Dendritic Cells/classification , Odontogenic Cysts/pathology , Adult , Antigens, CD/analysis , Antigens, CD1/analysis , Cell Lineage , Dendritic Cells/pathology , Dentigerous Cyst/pathology , Epithelium/pathology , Female , Humans , Immunoglobulins/analysis , Immunophenotyping , Lectins, C-Type/analysis , Male , Mannose-Binding Lectins/analysis , Membrane Glycoproteins/analysis , Middle Aged , Odontogenic Tumors/pathology , Radicular Cyst/pathology , S100 Proteins/analysis , CD83 Antigen
6.
SADJ ; 67(10): 582-4, 2012 Nov.
Article in English | MEDLINE | ID: mdl-23957101

ABSTRACT

This is a review of the main clinical and microscopical features of the most common sarcomas of the soft tissues of the head and neck.


Subject(s)
Head and Neck Neoplasms/diagnosis , Sarcoma/diagnosis , Soft Tissue Neoplasms/diagnosis , Humans , Rhabdomyosarcoma/diagnosis
7.
Histopathology ; 2012 Jun 20.
Article in English | MEDLINE | ID: mdl-24750244

ABSTRACT

AIMS: Signet-ring cell (SRC) change has not been reported in adenoid cystic carcinomas (ACC). This study describes the clinicopathological and immunohistochemical findings in four cases of ACC with SRCs (ACC-SRC), in which the relative proportion of the SRC component ranged from 25% to 50%. METHODS AND RESULTS: The median age was 58 years (range: 48 to 81 y) and all patients were women. The involved sites were sinonasal, lip and submandibular. Two patients developed lung metastasis and one died of disease 63 months after tumor resection. Neither mucinous nor lipid substances were detected in the SRCs. These were positive for AE1/AE3, CK14 and EMA; which highlighted the intracytoplasmic vacuole borders. The SRC nests were surrounded by α-SMA and p63 positive myoepithelial cells. When compared to the conventional component, the SRCs exhibited similar p53 positivity but lower Ki-67 and mitotic indices. SRCs were C-Myb negative. Ultrastructural examination revealed that the intracytoplasmic vacuoles were lumens lined by microvilli. CONCLUSIONS: ACC-SRC is a nonmucin and nonlipid producing phenomenon, possibly related to disturbed differentiation of ductal/luminal cells. This cellular modification in ACC apparently does not change the biological behavior of the tumor but it may cause significant diagnostic problems, particularly in incisional biopsies. © 2012 Blackwell Publishing Ltd.

8.
Oral Dis ; 17(8): 808-12, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21819495

ABSTRACT

OBJECTIVE: The aim of this study was to determine the expression of fatty acid synthase (FASN) in oral nevi and melanomas, comparing the results with correspondent cutaneous lesions. MATERIALS AND METHODS: Expression of FASN was evaluated by immunohistochemistry in 51 oral melanocytic lesions, including 38 intramucosal nevi and 13 primary oral melanomas, in 10 cutaneous nevi and in 14 melanomas. RESULTS: Fatty acid synthase was strongly expressed only in melanomas, either of the oral mucosa or cutaneous. On the other hand, most oral and cutaneous nevi were negative, with a few oral cases showing focal and weak expression. CONCLUSION: Fatty acid synthase is expressed in malignant melanocytes, and it can be a helpful marker to distinguish oral melanomas from oral melanocytic nevi.


Subject(s)
Fatty Acid Synthases/analysis , Melanoma/enzymology , Mouth Neoplasms/enzymology , Nevus/enzymology , Adolescent , Adult , Aged , Aged, 80 and over , Antibodies , Biomarkers, Tumor/analysis , Coloring Agents , Female , Humans , Immunohistochemistry , Male , Melanocytes/enzymology , Middle Aged , Mouth Mucosa/enzymology , Nevus, Intradermal/enzymology , Nevus, Pigmented/enzymology , Skin Neoplasms/enzymology , Young Adult
9.
Int J Oral Maxillofac Surg ; 40(9): 994-7, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21550206

ABSTRACT

Squamous cell carcinomas (SCCs) are amongst the commonest malignancies in adults but in paediatric patients are exceptionally rare, particularly those involving the oral mucosa. The aim of the present report is to describe the features of a gingival well-differentiated SCC in a 7-year-old Brazilian boy. Immunostaining for p53, Ki-67 and Mcm2 showed increased cellular proliferation compared with normal epithelium. In situ hybridization failed to identify human papilloma virus infection. Correct diagnosis of well-differentiated squamous carcinoma can be difficult in children and differentiation from pseudoepitheliomatous hyperplasia is essential to establish proper treatment.


Subject(s)
Carcinoma, Squamous Cell/pathology , Gingival Hyperplasia/pathology , Gingival Neoplasms/pathology , Age of Onset , Carcinoma, Squamous Cell/surgery , Child , Diagnosis, Differential , Gingival Neoplasms/surgery , Humans , Male , Maxilla , Treatment Outcome
10.
Int J Oral Maxillofac Surg ; 38(4): 388-92, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19217261

ABSTRACT

Cysts of the tongue are rare, usually derived from epithelia of the embryonic gastrointestinal and respiratory tracts, and classified according to the predominant epithelium lining. These cysts are usually discovered during infancy, more frequently in males, but they may not appear until well into adulthood. The authors report two lingual cysts lined mainly with respiratory, and focally by squamous, epithelium. Periodic acid-Schiff and mucicarmine staining revealed focal positivity in intracystic mucoid material and goblet cells. Immunohistochemical analysis with vimentin, cytokeratins (AE1/AE3, 34betaE12, CK1, CK5, CK6, CK7, CK8, CK10, CK13, CK14, CK16, CK18, and CK19), E-cadherin, beta-catenin, and epithelial membrane antigen showed a similar profile of normal respiratory epithelium, suggesting well-differentiated states. Owing to their controversial origin, these cysts should be named descriptively, as suggested by Manor et al., as lingual cysts with respiratory epithelium.


Subject(s)
Choristoma/pathology , Cysts/pathology , Respiratory Mucosa/pathology , Tongue Neoplasms/pathology , Child, Preschool , Choristoma/metabolism , Choristoma/surgery , Cysts/metabolism , Cysts/surgery , Humans , Immunohistochemistry , Keratins/classification , Keratins/metabolism , Male , Respiratory Mucosa/metabolism , Tongue Neoplasms/metabolism , Tongue Neoplasms/surgery , Vimentin/metabolism , Young Adult
11.
J Oral Pathol Med ; 38(1): 120-5, 2009 Jan.
Article in English | MEDLINE | ID: mdl-19192057

ABSTRACT

BACKGROUND: This study describes the histopathological, immunohistochemical (IHC) and in situ hybridization (ISH) data of 25 cases of oral ulcers in HIV-positive patients, with clinical and microscopical features similar to ulcers not otherwise specified (NOS)/necrotizing ulcerative stomatitis (NUS). METHODS: Sex, age and clinical history were obtained from the clinical records. Histological analysis for H&E, Gomori-Grocott and Ziehl-Neelsen stains, IHC analysis to detect infectious agents and to characterize inflammatory cellular infiltrate, and ISH for cytomegalovirus (CMV) and EBER1/2 were performed. RESULTS: Twenty-one patients were men and four were women (mean age of 34.6 years). The tongue was preferentially affected. Microscopically, the lesions showed extensive necrosis, leukocytoclasia, vasculitis with luminal fibrin clots and an intense inflammatory cellular infiltrate predominated by CD68(+) atypical large cells, normal-sized and crescent-shaped nuclei macrophages, interspersed by CD8(+) T lymphocytes. Mast cells were also observed in all samples studied. CD4(+) T lymphocytes, CD20(+) B lymphocytes and VS38c(+) plasma cells were practically absent. CMV and EBER1/2 were identified in scarce cells of 3 and 16 of 25 cases respectively. CONCLUSION: These results show that CD68(+) macrophages, followed by CD8(+) T lymphocytes, were the predominant inflammatory cells, indicating they are relevant to the pathogenesis of the ulcers, possibly reflecting an abnormal immune response in the oral mucosa. The clinicopathological and immunoprofile features of the present cases are similar to NOS ulcers/NUS in HIV-positive patients.


Subject(s)
HIV Seropositivity/pathology , Oral Ulcer/pathology , AIDS-Related Opportunistic Infections/pathology , AIDS-Related Opportunistic Infections/virology , Adult , Antigens, CD/analysis , Antigens, CD20/analysis , Antigens, Differentiation, Myelomonocytic/analysis , B-Lymphocytes/pathology , B-Lymphocytes/virology , CD4-Positive T-Lymphocytes/pathology , CD4-Positive T-Lymphocytes/virology , CD8-Positive T-Lymphocytes/pathology , CD8-Positive T-Lymphocytes/virology , Cytomegalovirus/isolation & purification , Female , Gingivitis, Necrotizing Ulcerative/pathology , Gingivitis, Necrotizing Ulcerative/virology , HIV Seropositivity/virology , Herpesvirus 4, Human/isolation & purification , Humans , Immunohistochemistry , In Situ Hybridization , Leukocytes/pathology , Leukocytes/virology , Macrophages/pathology , Macrophages/virology , Male , Mast Cells/pathology , Mast Cells/virology , Middle Aged , Necrosis , Oral Ulcer/virology , Peru , Plasma Cells/pathology , Plasma Cells/virology , Thrombosis/pathology , Thrombosis/virology , Vasculitis/pathology , Vasculitis/virology
12.
Int J Oral Maxillofac Surg ; 37(8): 773-6, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18372161

ABSTRACT

Subgemmal neurogenous plaques, biphasic structures with a neurofibroma and neuroma patterns, are observed in tongue biopsies involving subepithelial areas, being characterized as aggregates of nerve plexus and ganglion cells. Oral burning symptoms, having many possible causes, are commonly observed during oral medicine practice, but the association of subgemmal neurogenous plaque with tongue burning symptoms is very unusual. Reported here are two cases of focal burning sensation in the lateral border of the tongue diagnosed as subgemmal neurogenous plaque through biopsy. Recognizing this entity is important to avoid misdiagnosis of other neural proliferations, especially in cases involving focal tongue burning.


Subject(s)
Burning Mouth Syndrome/pathology , Ganglia/pathology , Neurofibroma/pathology , Neuroma/pathology , Neurons/pathology , Tongue Neoplasms/pathology , Adult , Female , Humans , Middle Aged , Taste Buds/pathology
13.
Oral Dis ; 14(1): 82-8, 2008 Jan.
Article in English | MEDLINE | ID: mdl-18173453

ABSTRACT

OBJECTIVE: Secretory leukocyte proteinase inhibitor (SLPI) is an endogenous proteinase inhibitor present in mucosal secretions. It also displays antimicrobial activity including anti-human immunodeficiency virus activity. This protease inhibitor is also expressed in submandibular glands (SMG), but there are few data on its expression in AIDS patients with infectious conditions. METHODS: We analyzed the expression of SLPI using immunohistochemistry in submandibular gland samples of 36 AIDS patients [10 with normal histology, 10 with chronic nonspecific sialadenitis, eight with mycobacteriosis, and eight with cytomegalovirus (CMV) infection] and 10 HIV-negative controls. The proteinase inhibitor was quantified using image analysis and expressed as % of positively stained area. RESULTS: There was a higher expression of SLPI in AIDS patients with CMV infection (% of stained area, mean+/-SD: 37.37+/-14.45) when compared with all other groups (P=0.009). There were no significant differences between control subjects (22.70+/-9.42%) and AIDS patients without histologic alterations (18.10+/-7.58%), with chronic nonspecific sialadenitis (17.13+/-5.36%), or mycobacterial infection (21.09+/-4.66%). CONCLUSION: Cytomegalovirus infection increases SLPI expression in the SMG of AIDS patients. Our results reveal new insights into the pathogenic association between HIV and CMV in AIDS patients.


Subject(s)
Acquired Immunodeficiency Syndrome/pathology , Secretory Leukocyte Peptidase Inhibitor/analysis , Submandibular Gland/pathology , AIDS-Related Opportunistic Infections/pathology , Adult , Aged , Cause of Death , Chronic Disease , Cytomegalovirus Infections/pathology , Female , HIV Seronegativity , Humans , Image Processing, Computer-Assisted , Immunohistochemistry , Male , Middle Aged , Mycobacterium Infections/pathology , Sialadenitis/pathology , Submandibular Gland Diseases/pathology
14.
Can J Anaesth ; 39(2): 128-34, 1992 Feb.
Article in English | MEDLINE | ID: mdl-1544194

ABSTRACT

The aims of this study were firstly, to determine the effect of various concentrations of isoflurane on cerebrovascular circulation and secondly, to examine the time-response characteristics of the drug on cerebral blood flow velocity in anaesthetized children. Thirty-two ASA physical status I or II patients aged one to eight years and scheduled for urological surgery were studied. Anaesthesia was induced with thiopentone 5 mg.kg-1 and fentanyl 2 micrograms.kg-1. Muscle relaxation was provided with vercuronium 0.1 mg.kg-1. Tracheal intubation was performed in all cases. Anaesthesia was maintained with isoflurane in a mixture of air and oxygen to produce an inspired oxygen fraction (FIO2) of 0.3. Ventilation was adjusted to maintain normocapnia. A caudal or lumbar epidural catheter was inserted before skin incision and a continuous bupivacaine, without epinephrine, infusion established. During the first part of this study, the initial isoflurane concentration for 24 patients was randomized and age-adjusted to 0.5 MAC, 1.0 MAC, or 1.5 MAC. After steady-state was reached, the subsequent isoflurane MAC concentration was randomized by either raising or lowering it from the initial concentration. In the second part of this study, the time-response effect of isoflurane was examined. Eight patients received 1.0 MAC isoflurane over 90 to 150 min. Temperature, heart rate, and systolic blood pressure were unchanged throughout the study. Cerebral blood flow velocity (CBFV) and resistance index (RI+), a measure of cerebrovascular resistance, were measured in the M1 segment of the middle cerebral artery (MCA) with a 2 MHz transcranial Doppler monitor.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Anesthesia, Inhalation , Brain/blood supply , Cerebrovascular Circulation/drug effects , Isoflurane/pharmacology , Vascular Resistance/drug effects , Blood Flow Velocity/drug effects , Child , Child, Preschool , Dose-Response Relationship, Drug , Echoencephalography , Humans , Infant , Isoflurane/administration & dosage , Time Factors
15.
Can J Anaesth ; 39(4): 409, 1992 Apr.
Article in English | MEDLINE | ID: mdl-27518514
16.
Can J Anaesth ; 38(8): 974-9, 1991 Nov.
Article in English | MEDLINE | ID: mdl-1752019

ABSTRACT

To determine the effect of nitrous oxide (N2O) on cerebral blood flow velocity (CBFV) and cerebrovascular resistance index (RI+) in children, ten ASA physical status I or II patients aged one to eight years old, scheduled for urological procedures, were studied. Anaesthesia was induced with thiopentone 2 mg.kg-1, fentanyl 5 micrograms.kg-1 and diazepam 0.3 mg.kg-1. Muscular relaxation was ensured by using vecuronium 0.1 mg.kg-1. After tracheal intubation, anaesthesia was randomly assigned to either a mixture of air in oxygen (N2/O2) or 70% N2O in oxygen (N2O/O2) producing an FIO2 of 30%. Three sets of measurements of CBFV and RI+ were made with both gas mixtures. The CBFV and RI+ were measured in the middle cerebral artery (MCA) with a transcranial Doppler monitor. Measurements were made while using the initial gas mixture, then the second gas mixture was administered, and finally, the patient again was given the initial gas mixture. A continuous caudal epidural or lumbar epidural block was performed before skin incision. Neuromuscular blockade was maintained with vecuronium 0.05 mg.kg-1. Temperature, heart rate, end-tidal CO2, arterial oxygen saturation, haematocrit and arterial blood pressure were maintained constant. Ventilation was adjusted to achieve normocapnia. The CBFV increased when 70% N2/O2 was replaced by 70% N2O/O2 (P less than 0.05) while the CBFV decreased when 70% N2/O2 was readministered (P less than 0.05). Likewise, the CBFV decreased when 70% N2O/O2 was replaced by 70% N2/O2 (P less than 0.05) while the CBFV increased when 70% N2O/O2 was readministered (P less than 0.05).


Subject(s)
Blood Flow Velocity/drug effects , Brain/blood supply , Cerebrovascular Circulation/drug effects , Echoencephalography , Nitrous Oxide/pharmacology , Vascular Resistance/drug effects , Anesthesia, Inhalation , Cerebral Arteries/diagnostic imaging , Cerebral Arteries/drug effects , Child , Child, Preschool , Echoencephalography/methods , Humans , Infant , Nitrogen/administration & dosage , Nitrous Oxide/administration & dosage , Oxygen/administration & dosage , Time Factors
17.
Can J Anaesth ; 38(7): 817-25, 1991 Oct.
Article in English | MEDLINE | ID: mdl-1742814

ABSTRACT

To determine the effects of isoflurane and halothane on cerebrovascular reactivity to CO2, 30 children aged one to six years were anaesthetized with isoflurane or halothane in an air and oxygen mixture with an FIO2 of 0.3. The end-tidal concentrations (0.5 minimum alveolar concentration (MAC) or 1.0 MAC) of isoflurane or halothane were age-adjusted. After achieving a steady-state at both 0.5 MAC and 1.0 MAC isoflurane and halothane, the end-tidal carbon dioxide tension (PETCO2) was randomly adjusted to 20, 40, or 60 mmHg. Cerebral blood flow velocity (CBFV) and the cerebrovascular resistance index (RI+) in the middle cerebral artery (MCA) were measured by a transcranial Doppler monitor. Three measurements of CBFV and RI+ were obtained at each PETCO2 and isoflurane or halothane concentration. Any rise in the PETCO2 caused an increase in CBFV during both 0.5 MAC (r2 = 0.99 and 0.99) and 1.0 MAC (r2 = 0.96 and 0.95) isoflurane and halothane anaesthesia, respectively (P less than 0.05). The CBFV for isoflurane increased as PETCO2 increased from 20 to 60 mmHg for both 0.5 MAC and 1.0 MAC (P less than 0.05). The CBFV for halothane increased as PETCO2 increased from 20 to 40 mmHg for both 0.5 MAC and 1.0 MAC halothane (P less than 0.05), but did not change as PETCO2 increased from 40 to 60 mmHg for both 0.5 MAC and 1.0 MAC halothane. The RI+ showed an inverse relationship with CBFV at each PETCO2 for 0.5 MAC (r2 = 0.98 and 0.99) and 1.0 MAC (r2 = 0.76 and 0.53) isoflurane and halothane, respectively (P less than 0.05). The CBFV did not differ significantly between 0.5 and 1.0 MAC isoflurane and halothane at corresponding PETCO2 values. The cerebrovascular response to CO2 at 20 mmHg between 0.5 MAC and 1.0 MAC halothane was not significantly different. These data strongly suggest that isoflurane and halothane in doses up to 1.0 MAC do not affect the cerebrovascular reactivity of the MCA to CO2 in anaesthetized, healthy children.


Subject(s)
Anesthesia, Inhalation , Carbon Dioxide/physiology , Cerebrovascular Circulation/physiology , Halothane , Isoflurane , Blood Flow Velocity , Cerebral Arteries/physiology , Child , Child, Preschool , Humans , Infant , Vascular Resistance/physiology
SELECTION OF CITATIONS
SEARCH DETAIL
...