Biomedical subjects

R Cristofani

Publications and source records attributed to R Cristofani.

At least 19 recordsLinked to original sources

PubMed2005

Ankyloglossia: a morphofunctional investigation in children.

OBJECTIVES: To provide diagnostic criteria for ankyloglossia in children by anatomical measurements; to investigate the correlation between severity of ankyloglossia and a series of morphofunctional findings; to evaluate the potential mismatch between a clinical suspect of ankyloglossia and the authentic anatomical diagnosis. DESIGN: Two different techniques of anatomical measurements and a clinical evaluation of a series of morphofunctional findings were performed. SUBJECTS AND METHODS: In 200 children referred for evaluation and treatment of tongue-tie, the length of the frenulum and the interincisal distance were measured in maximum opening of the mouth and with the tip of the tongue touching the palatal papilla. Occlusion, type of bite, tongue resting position, swallowing mechanism, oral floor mobility, frenulum insertion modality and speech were investigated. Any correlation between these morphofunctional findings and anatomical measures was investigated. RESULTS: Children with a frenulum length more than 2 cm and an interincisal distance of more than 2.3 cm were normal. In both measurements, significant correlations among mean values and other variables were observed. Moreover, three levels -- mild, moderate and severe -- of ankyloglossia were assessed. CONCLUSIONS: Length of frenulum and interincisal distance allow an assessment of severity of ankyloglossia in children. Ankyloglossia was not associated with infantile swallowing.

Anthropometry↗

PubMed2004

Oxidative and genotoxic damage after radio-iodine therapy of Graves' hyperthyroidism.

PURPOSE: To evaluate genetic damage and oxidative stress following a single therapeutic dose of 131I in Graves' disease patients monitored up to 180 days after treatment. MATERIALS AND METHODS: Genetic damage induction was estimated as the increase in micronuclei in peripheral lymphocytes of patients. As indicators of radiogenic oxidative stress, vitamin E and lipoperoxide levels were assessed in the plasma of patients, as well as the release of plasmic clastogenic factors measured by the induction of micronuclei in vitro in peripheral lymphocytes of a healthy donor. RESULTS: Vitamin E depletion lasted at least 3 days and the basal level was restored within 7 days. No statistically significant variations were observed in lipoperoxide plasma levels. A sharp increase of micronuclei in the peripheral lymphocytes of patients was correlated (p < 0.001) with the release of clastogenic factor in the plasma. The highest micronucleus value was negatively correlated (p < 0.03) with the lowest vitamin E level observed in each patient. CONCLUSIONS: Micronuclei induction was the direct consequence not only of the energy deposition of 131I on the genetic material, but also of oxidative stress, likely via the release of clastogenic factor.

Adult↗

PubMed2004

[Surgical treatment of umbilical hernia in children. Our experience].

AIM: To identify the main parameters which, differently correlated, indicate in which case, age and modality umbilical hernia in children should be surgically repaired. METHODS: The authors report personal experience on 319 children with umbilical hernia observed in the last 7 years. In 72 cases, on the basis of the evaluation of some parameters, a surgical correction was performed with the technique described. RESULTS: All the procedures were performed in "day surgery". There were no early complications, neither anesthetic nor surgical. All children showed a good recovery of all functions (feeding, intestinal canalization, walking about) and activities. No middle and long-term complications were observed. CONCLUSIONS: Umbilical hernia needs a surgical repair only in a few cases and after a careful evaluation of some parameters (age, sex, kind of hernia, size and consistency of the hernial porta, protrusion and expansion). The surgical procedure should guarantee either the safe and prompt repair or the cosmetic result; the use of some devices (anesthetic and surgical) allow to obtain excellent results.

Ambulatory Surgical Procedures↗

PubMed2003

A comparison of ultrasonography and magnetic resonance imaging in the evaluation of temporomandibular joint involvement in rheumatoid arthritis and psoriatic arthritis.

OBJECTIVE: To define the diagnostic value of ultrasonographic (US) examination in comparison with magnetic resonance imaging (MRI) for the assessment of temporomandibular joint (TMJ) involvement in rheumatoid arthritis (RA) and psoriatic arthritis (PsA). METHODS: MRI and US examinations were performed in 33 patients (22 with RA and 11 with PsA). Alterations of the disc, alterations of the condyle and joint effusion were evaluated. RESULTS: Pathological changes of the TMJ were observed by MRI in 24 patients and by US in 31 patients. The sensitivity and specificity of US were calculated in comparison with MRI. The sensitivity was 72.2% and the specificity was 60% in the assessment of pathological changes of the TMJ. The sensitivity was 69.6% with specificity of 30.0% in the assessment of alterations of the disc; the sensitivity was 70.6% with specificity of 75.0% in the assessment of joint effusion. Significant concordance was not observed in the assessment of condylar alterations. CONCLUSIONS: US imaging appears able to detect different pathological changes of the TMJ and may be considered an important diagnostic tool for clinical evaluation of the TMJ in RA and PsA.

Adult↗

PubMed2003

[Anastomotic false-diverticulum causing an atypical dumping syndrome. A case report].

Aim of the study is to evaluate the causes of dumping syndromes following partial gastrectomies, and to report an unusual feature of dumping. A case of early dumping due to diverticular-like dilation of gastro-jejunal anastomosis is described with preoperative imaging and intraoperative picture. The surgical correction led to complete clinical remission; the common causes and physiopathological bases of dumping are reviewed and the role of en-Y gastro-jejunal reconstruction is underlined in order to reduce the risk of developing the syndrome.

Anastomosis, Roux-en-Y↗

PubMed2003

Is pretreatment hemoglobin level a predictor of complete response to salvage chemotherapy for recurrent platinum-pretreated ovarian carcinoma?

PURPOSE OF INVESTIGATION: The aim of this retrospective study was to correlate some patient characteristics at relapse, including also baseline hemoglobin levels, with complete response rate and survival following second-line chemotherapy for recurrent platinum-pretreated ovarian carcinoma. METHODS: The investigation was conducted on 63 patients who received salvage chemotherapy with different agents for clinically detectable recurrent ovarian carcinoma following initial surgery and first-line platinum-based chemotherapy. Some patient characteristics at relapse (patient age, serum CA 125 level, baseline hemoglobin level, number of recurrence sites, ascites, platinum-free interval, and treatment-free interval) were related to complete response rate to salvage chemotherapy and survival after recurrence. Median baseline hemoglobin level was 11.6 g/dl (range, 7.5-15.0 g/dl). RESULTS: Second-line chemotherapy obtained a complete response in 17 (27.0%) patients and a partial response in 11 (17.5%), whereas stable disease and progressive disease were detected in 19 (30.1%) and 16 (25.4%) patients, respectively. By univariate analysis, complete response rate was related to baseline hemoglobin level (p = 0.0019), platinum-free interval (p = 0.0012) and treatment-free interval (p = 0.0048). Multiple logistic regression showed that platinum-free interval (p = 0.0107) and baseline hemoglobin level (0.0312) were independent predictors of complete response. Patients with baseline hemoglobin levels >11.6 g/dl had a 5.338 higher chance of obtaining a complete response when compared to those with lower hemoglobin values. The platinum-free interval was the only independent prognostic variable for survival after recurrence (p = 0.0141), whereas baseline hemoglobin level was not related to survival at univariate nor at multivariate analysis. CONCLUSIONS: Baseline hemoglobin level is an independent predictor of complete response to salvage chemotherapy in patients with recurrent platinum-pretreated ovarian carcinoma. Attention must be paid to anemia correction in these patients, with the aim of improving both the chance of response to salvage treatment and the quality of life.

Adult↗

PubMed2002

The prognostic relevance of histological type in uterine sarcomas: a Cooperation Task Force (CTF) multivariate analysis of 249 cases.

PURPOSE OF INVESTIGATION: The objective of this retrospective multicenter study was to assess the prognostic relevance of histologic type in uterine sarcomas. METHODS: The hospital reports of 249 patients with uterine sarcomas were reviewed. Surgery was the initial therapy for all patients. Histologic type was leiomyosarcoma in 95 cases, low-grade endometrial stromal sarcoma (ESS) in 19, high-grade ESS in 34, and carcinosarcoma in 101. Postoperative treatment was given without well-defined protocols. Median follow-up of survivors was 97 months. RESULTS: In the whole series 2-year, 5-year, and 10-year survival rates were 53.5%, 41.6%, and 35.8%, respectively, and median survival was 31 months. At univariate analysis survival was significantly related to stage (p = 0.0001), mitotic count (p = 0.0001), and histologic type (low-grade ESS vs leiomyosarcoma vs carcinosarcoma vs high-grade ESS, median: not reached vs 27 months vs 21 months vs 16.5 months, p = 0.0011), but not to postoperative therapy and patient age. The Cox model revealed that tumor stage, mitotic count and histologic type were independent prognostic variables for survival. In detail, the risk of death was significantly lower for low-grade ESS (risk ratio [RR] = 0.257; 95% confidence interval [CI] = 0.071-0.931) and carcinosarcoma (RR = 0.509; 955 CI = 0.324-0.799) when compared to leiomyosarcoma. Conversely, no significant difference in survival was found between leiomyosarcoma and high-grade ESS. CONCLUSIONS: Histologic type is an independent prognostic variable for survival in uterine sarcomas. Low-grade ESS has the best clinical outcome, whereas leiomyosarcoma has the poorest one. It is noteworthy that, when adjusting for stage and mitotic count, leiomyosarcoma has a significantly worse prognosis than carcinosarcoma.

Adult↗

PubMed2002

[The use of surgical endo-prosthesis in the treatment of choledocolithiasis in the elderly. Personal experience].

BACKGROUND: The usefulness of biliary endoprostheses in some selected elderly patients affected by hepato-choledocolithiasis is described. METHODS: In the Department of Surgery, University of Perugia, 119 elderly patients were surgically treated for choledocholithiasis from January 1999 to December 2000. In 44 selected cases#151;oldest patients with thinner hypovascularized ectasic choledochal wall#151; a permanent transpapillary polyurethane prosthesis was placed, after choledocolithotomy with or without sphinterotomy; sometimes prosthesis was placed under the duodenal mucosa. RESULTS: Endoprosthesis had a long duration and gave good results in canalization and periprosthetic flow, in absence of biliary stasis and/or angiocholitis. Only one patient had prostheses displacement. CONCLUSIONS: On the basis of personal experience and considering physiopathology and pathogenesis of biliary stones in the elderly, the authors underline, in selected cases, the need of stenting the hepatocholedochal lumen with the aim of avoiding collapse.

Aged↗

PubMed2001

Regional lymph node dissection in the treatment of renal cell carcinoma: is it useful in patients with no suspected adenopathy before or during surgery?

OBJECTIVES: To evaluate the role of regional lymph node dissection (LND) in a series of patients with renal cell carcinoma (RCC) with no suspicion of nodal metastases before or during surgery. PATIENTS AND METHODS: A series of 167 patients with RCC, free from distant metastases at diagnosis, and who underwent radical nephrectomy at our hospital between January 1990 and October 1997, was reviewed. The mean (median, range) follow-up was 51 (45, 19-112) months. Of the 167 patients, 108 underwent radical nephrectomy alone and 59 had radical nephrectomy with regional LND limited to the anterior, posterior and lateral sides of the ipsilateral great vessel, from the level of the renal pedicle to the inferior mesenteric artery. Of these 59 patients, 49 had no evidence of nodal metastases before or during surgery. The probability of survival was estimated by the Kaplan-Meier method, using the log-rank test to estimate differences among levels of the analysed variables. RESULTS: The overall 5-year survival was 79%; the 5-year survival rate for the 108 patients who underwent radical nephrectomy alone was 79% and for the 49 who underwent LND was 78%. Of the 49 patients with no suspicion of lymph node metastases, one (2%) was found to have histologically confirmed positive nodes. CONCLUSION: These results suggest that there is no clinical benefit in terms of overall outcome in undertaking regional LND in the absence of enlarged nodes detected before or during surgery.

Adult↗

PubMed2001

Hemostatic alterations in patients with acute, unilateral vestibular paresis.

OBJECTIVES: The etiopathogenesis of acute unilateral peripheral vestibulopathy (APV) still remains a matter of debate; ischemic changes in the circulation of the labyrinth may play a role. We consequently looked for possible hemostasis alterations in a group of patients with APV of an unknown nature. METHODS: We evaluated blood parameters known to be involved in circulation disorders, including total and HDL cholesterol, triglycerides, apolipoprotein A and B, lipoprotein(a), homocysteine, folate, prothrombin time, activated partial thromboplastin time, fibrinogen, D-dimer, antithrombin III, protein C, protein S, activated protein C resistance, and anticardiolipin IgG and IgM antibodies. A series of 23 patients affected with APV were consecutively referred to our department, in the acute phase, before treatment, and in the follow-up phase after 4 to 6 weeks of pharmacologic washout. The aforementioned blood parameters were also measured in a series of 15 patients with Menière's disease. RESULTS: The patients with APV in the acute phase compared with the patients with Menière's disease in the acute phase exhibited increased plasma levels of fibrinogen (mean, 338.3 +/- 135.9 SD vs 271.3 +/- 69.8 SD mg/dL, P = 0.05), increased plasma levels of D-dimer (mean, 320 +/- 207.8 SD vs 226.7 +/- 138.7 SD NG/mL), enhanced plasma levels of lipoprotein(a) (41.4 +/- 38.6 SD vs 16 +/- 18.2 SD mg/dL, F = 5.67, P = 0.02), high leukocyte count (9.1 +/- 2.7 SD vs 6.5 +/- 1.3 SD x 10(3)/microL; F = 8.42, P < 0.006), and low serum folate concentration (5.3 +/- 1.8 SD vs 7.1 +/- 2.7 NG/mg; F = 4.34, P = 0.04). During follow-up the prothrombin time was prolonged (F = 4.34, P = 0.04) and leukocyte count decreased (F = 7.39, P < 0.019) in the APV patients, whereas fibrinogen, D-dimer, lipoprotein(a), and folate were unchanged. CONCLUSION: Our results provide evidence suggesting an involvement of the hemostatic system in APV.

Acute Disease↗

PubMed2000

Complete salvage surgical cytoreduction improves further survival of patients with late recurrent ovarian cancer.

OBJECTIVE: The aim of this study was to assess the clinical benefit of salvage surgical cytoreduction in patients with late recurrent ovarian cancer. METHODS: Thirty patients with recurrent ovarian cancer who underwent salvage surgical cytoreduction were retrospectively reviewed. All had been initially treated by primary surgery and platinum-based chemotherapy and had a period of clinical remission of at least 6 months. Median time to recurrence was 17.5 months (range, 6-76 months). RESULTS: A macroscopically complete salvage cytoreduction was obtained in 17 (56.7%) patients, whereas 8 patients were left with macroscopic residual disease <2 cm and 5 patients with a larger residuum. Logistic regression showed that the probability of achieving a complete cytoreduction was significantly related to the residual disease after initial surgery (<2 cm versus >2 cm, P = 0.0027, odds ratio = 36.000, 95% confidence interval = 3. 473-373.176), but not to FIGO stage, tumor grade, histologic type, patient age at recurrence, and time to recurrence. In the whole series median survival following salvage surgery was 21 months. Survival was significantly longer in patients who were completely cytoreduced compared to those who were not (median: 37 months versus 19 months, P = 0.04). Moreover, survival was significantly related to time to recurrence (>17.5 months versus <17.5 months, median: 25 months versus 15 months, P = 0.039), number of recurrence sites (single versus multiple, median: 40 months versus 19 months, P = 0. 009), and residual disease after initial surgery (<2 cm versus >2 cm, median: 37 months versus 19 months, P = 0.01), but not to patient age, recurrence site with the largest size, FIGO stage, tumor grade, and histologic type. CONCLUSIONS: The present data seem to show that complete salvage surgical cytoreduction significantly improves further survival of ovarian cancer patients who recur at least 6 months after the completion of primary therapy.

Adult↗

PubMed2000

Evaluation of the 1997 tumour, nodes and metastases classification of renal cell carcinoma: experience in 172 patients.

OBJECTIVE: To compare the prognostic relevance of the 1987 and 1997 tumour, nodes and metastases (TNM) systems for staging renal cell carcinoma (RCC) in predicting patient outcome. PATIENTS AND METHODS: A series of 172 consecutive patients with RCC who underwent radical nephrectomy from January 1990 to October 1997 was evaluated comparatively according to the 1987 and 1997 TNM classifications. The median (range) follow-up of the patients was 50 (19-112) months. The probability of survival was estimated by the Kaplan-Meier method, using the log-rank test to estimate differences among levels of the analysed variables. RESULTS: Using the 1997 TNM classification resulted in a redistribution of 99 patients from stage pT2 on the 1987 TNM classification to stage pT1. As the staging criteria for pT3 and pT4 did not change, there was no re-classification of these patients. Kaplan-Meier survival curves showed a similar separation in 5-year survival between stage pT1 and pT2 using both systems; 100% vs 80% for the 1987 TNM and 86% vs 69% for the 1997 TNM systems. This difference in survival rates between patients with pT1 and pT2 disease was statistically significant only for the 1997 TNM staging system. However, when the 1987 TNM staging classification was applied, the separation in 5-year survival rates between pT2 and pT3 disease was greater. CONCLUSION: This study confirms the prognostic relevance of the 1987 TNM system, as established in the present patients. The 1997 TNM classification resulted in a better stratification of patients with pT1-pT2 disease, but had similar prognostic value for pT2 and pT3 disease.

Adult↗

PubMed2000

Plasma C-reactive protein in hemodialysis patients: a cross-sectional, longitudinal clinical survey.

In hemodialysis patients, C-reactive protein (CRP), an acute-phase reactant, is a sensitive and independent marker of malnutrition, anemia, and amyloidosis. The aim of the present studies was to evaluate CRP and interleukin 6 levels in plasma samples from long-term hemodialysis patients on different extracorporeal modalities associated with or without backfiltration. Two hundred and forty-seven patients were recruited in eight hospital-based centers. All patients had been on their dialytic modality for at least 6 months. At enrollment, 46 hemodialysis patients out of 247 (18.6%) had clinical evidence of pathologies known to be associated with high CRP values. The 201 remaining patients were defined as clinically stable and were on conventional hemodialysis (34%), hemodiafiltration with infusion volumes <10 liters/session (10%), hemodiafiltration with infusion volumes <20 liters/session (32%), and double-chamber hemodiafiltration with infusion volumes <10 liters/session (22%). Analysis of CRP values in the clinically stable patients showed that an unexpectedly high proportion (47%) of the patients had CRP values higher than 5 mg/l (taken as the upper limit in normal human subjects). The values of CRP and interleukin 6 were significantly higher in hemodiafiltration with infusion volumes <10 liters/session than in hemodiafiltration with infusion volumes >20 liters/session, in hemodialysis and in double-chamber hemodiafiltration. The same pattern occurred after 6 months of follow-up in 171 out of 201 clinically stable patients. Hemodialytic conditions that expose to the risk of backfiltration such as low exchange volume hemodiafiltration may induce a chronic inflammatory state as reflected by increased plasma values of both CRP and interleukin 6, thus suggesting the need for hemodialytic strategies that reduce (hemodialysis with low-permeability membranes or hemodiafiltration with infusion volumes >20 liters) or eliminate (double-chamber hemodiafiltration) backfiltration of bacteria-derived contaminants.

Acute-Phase Proteins↗

PubMed2000

[Microinvasive carcinoma of the uterine cervix. Risk factors and therapeutic options].

Aim of this study was to analyze the staging of disease according to correlation between depth of stromal invasion, lymph vascular space involvement, nodal metastases and recurrence and mortality rates in uterine cervical carcinoma. Data of 16 different surveys from 1980 to 1996 inclusive were collected through a Medline research; papers were selected according to available information about depth of invasion, lymph vascular invasion, nodal metastases, recurrence and mortality rate. Results of these surveys were pooled with the following aims: 1 correlation between depth of invasion and nodal metastases occurrence; 2 evolution of prognostic value of lymph vascular invasion; 3 best management according to biology of disease. Depth of stromal invasion seems to be the most important prognostic factor in early cervical cancer, with a critical cut-off of 3 mm of depth. Lymph vascular invasion correlates both with nodal metastases and with prognosis, which strictly depends only on depth of invasion; as a consequence, lymph vascular invasion would not represent an independent prognostic factor. Finally radical treatment (i.e. more aggressive therapies) does not add any curative advantage when compared with conservative treatment, which must be currently considered standard in stage IA cervical cancer.

Female↗

PubMed1999

Endogenous androgens and carotid intimal-medial thickness in women.

The influence of endogenous androgens on atherosclerotic disease in women is unknown. In this study involving 101 pre- and post-menopausal females, we evaluated the relationship between serum androgen levels and both carotid artery intimal-medial thickness (IMT) and major cardiovascular risk factors. In addition to evaluation of blood pressure, body mass index, and waist-to-hip ratio, serum dehydroepiandrosterone sulfate (DHEA-S), androstenedione (A), total testosterone (TTS), free testosterone (FTS), insulin, cholesterol (total and high density lipoproteins), triglycerides, and glucose were measured. All women underwent carotid ultrasonography. Spearman correlation coefficients showed that serum DHEA-S and A levels were negatively related (P < 0.03-0.0004) to several IMT measures. Higher tertiles of DHEA-S, A, and FTS corresponded to significantly lower measures of carotid thickness. DHEA-S, and all androgens were inversely related to age (P < 0.03 or less), showing no unfavorable association with major cardiovascular risk factors. In contrast, serum DHEA-S was negatively associated with WHR (P < 0.02), while A was negatively associated with body mass index (P < 0.02). Stepwise multiple regression analysis indicated that A and FTS showed an inverse association with IMT measures (P < 0.05-0.001). In conclusion, our data indicate that in women serum DHEA-S and androgens decline with age and that normal hormonal levels are not associated with major cardiovascular risk factors. They also show that higher DHEA-S and androgen concentrations are related to lower carotid wall thickness; for A this association is independent of cardiovascular risk factors. Our results suggest that, in the physiological range, DHEA-S and androgens in women are correlated with lower risk of carotid artery atherosclerosis.

Adult↗

PubMed1998

Analysis of failures after negative second-look in patients with advanced ovarian cancer: an Italian multicenter study.

This multicenter retrospective study is based on 192 patients with advanced ovarian cancer in pathological complete response at second-look surgery. Ninety-four (48.9%) patients developed recurrent disease after a median time of 18 months (range, 4-89 months) from surgical reassessment. The recurrence involved the pelvis in 45 (47.9%) cases, the abdomen in 42 (44.7%), the retroperitoneal lymph nodes in 13 (13.8%), and distant sites in 20 (21.2%). On the whole series, 5- and 7-year disease-free survival rates after negative second-look were 47.4 and 44.5%, respectively. By log-rank test the disease-free survival rate was related to FIGO stage (P = 0.008), tumor grade (P = 0.0021), size of residual disease after initial surgery (P = 0.0038), and type of second-look (laparoscopy vs laparotomy, P = 0.0061), but not to histological type and first-line chemotherapy. Cox proportional hazard model showed that tumor grade, size of residual disease, and type of second-look were independent prognostic variables for disease-free survival. The risk ratio of relapse was 2.386 (95% CI, 1.140-4.990) for grade 2 and 3.118 (95% CI, 1.515-6.416) for grade 3 compared to grade 1 disease. For patients with residual disease 1-2 cm and > 2 cm the risk ratio was, respectively, 1.877 (95% CI, 1.117-3.156) and 2.156 (95% CI, 1.324-3.511) compared to patients with residual disease < 1 cm. The risk ratio was 1.826 (95% CI, 1.121-2.973) for patients who were submitted to a laparoscopic second-look compared to those who underwent a laparotomic reassessment. Poorly differentiated grade and large residual disease after initial surgery are the strongest prognostic variables for recurrence after a negative second-look.

Adult↗

PubMed1998

Accuracy of cervical/vaginal cytology in the diagnosis of bacterial vaginosis.

BACKGROUND AND OBJECTIVES: The cytological pattern of bacterial vaginosis (BV) in the Papanicolaou smear has a controversial history (coccoid vs. Gardnerella type) that has not allowed an efficient use of cervical/vaginal cytology in the diagnosis of this condition. Our study is an attempt to clarify this topic. GOALS: To evaluate the accuracy of cervical/vaginal cytology in the diagnosis of BV. STUDY DESIGN: 1,896 separate examinations were performed on 1,471 women attending our sexually transmitted diseases center between 1990 and 1993. Amsel's composite clinical criteria were used as a gold standard. The Pap smear was prepared on two slides with the addition of a vaginal specimen. RESULTS: In the 166 cases of BV, sensitivity is 88.7%, and specificity is 98.8%. Positive predictive value is 89.8, and negative predictive value is 98.7. Kendall's correlation coefficient is 0.88 (p < 0.001). CONCLUSIONS: Our findings support the validity of the vaginal Pap smear in diagnosing BV and suggest the screening of such a disease.

Female↗

PubMed1997

SEM/TEM investigation of rat cardiac subcellular alterations induced by changing duration of noise stress.

BACKGROUND: Many studies have shown that loud noise is an environmental stressor. Noise exposure causes changes at different levels in living beings; the cardiovascular system, considered to be the most affected apparatus, has received much attention in both animals and humans. The present study investigated the effect of changing duration of noise stimulation on rat myocardium to determine whether the responses could be related to time. METHODS: The study was performed on young albino male rats. Three groups of animals were exposed to white noise (100 dBA) for 1, 6, and 12 hr, respectively, and samples of right atrium and ventricle were processed for ultrastructural examination. The subcellular organization of cardiomyocytes was examined by transmission and scanning electron microscopy, the latter being carried out with the modified osmium maceration method. RESULTS: After 1 hr of noise exposure, atrial and ventricular cardiomyocytes did not present significant alterations. After 6 hr, changes were observed in atrial tissue at the mitochondrial level, whereas the ventricular structure appeared unaffected. After 12 hr of treatment, in addition to the mitochondrial alterations, changes in atrial and ventricular myocardium, consisting of areas of enlargement in intercalated disc membranes and decreased density in sarcoplasm, were detected. CONCLUSIONS: The methods we applied for the visualization of cellular organelles allowed us to demonstrate that atrial tissue is primarily involved in stress response, especially at the mitochondrial level; a more prolonged time of exposure seems to be necessary for ventricular involvement.

Animals↗