Complications of total thyroidectomy performed by surgical residents versus specialist surgeons

PURPOSE: Surgeon inexperience has been defined as a significant predictor of deleterious outcome in thyroid surgery; however, the safety of training programs in which residents are the primary surgeons is controversial. The objective of this prospective study was to compare the complication rates of total thyroidectomy (TT) performed by residents with those of TT performed by specialist surgeons in similar patient groups. METHODS: Between April 2001 and May 2007, 144 patients underwent TT at our hospital. For 75 operations, the primary surgeon was a resident under the direct supervision of the attending surgeon, and for 69 operations, the primary surgeon was the experienced attending surgeon. Pre-and postoperative vocal cord examinations and serum calcium level evaluations were carried out in all patients. RESULTS: The rates of temporary (unilateral) recurrent laryngeal nerve (RLN) palsy were 2.66% vs 2.17% after TT performed by the residents vs the attending surgeon, respectively. There were no significant differences in the incidences of temporary hypoparathyroidism (20% vs 20.28%), permanent (unilateral) RLN palsy, hematoma, infection, seroma, and incidental parathyroidectomy between the two groups. CONCLUSION: The complication rates of TT performed by residents and attending surgeons were similar. Thus, residents can perform TT safely and effectively under the direct supervision of a senior surgeon. Ultimately, strict adherence to the contemporary principles of thyroid surgery is of paramount importance.     

Acute effect of cigarette smoking on heart rate variability

Acute cigarette smoking enhances adrenergic activity and thus may be associated with hemodynamic changes in the cardiovascular system. In this study, the acute effect of cigarette smoking on heart rate variability (HRV) was studied. Fifteen subjects were included in the study. Time domain (the mean R-R interval, the standard deviation of R-R interval, and the root mean square of successive R-R interval differences) and frequency domain (high-frequency, low-frequency ratio, and low-frequency/high-frequency ratio) parameters of HRV were obtained from all participants for each 5-minute segment: 5 minutes before and 5, 10, 15, 20, 25, and 30 minutes after smoking a cigarette. The mean R-R interval, the standard deviation of R-R interval, and the root mean square of successive R-R interval differences significantly decreased within the first 5-minute period compared with baseline, and then the standard deviation of R-R interval increased within the 20- to 30-minute period. The low-frequency high-frequency ratio significantly decreased within the first 5 minutes after smoking and then remained unchanged throughout the study period. Similarly, low-frequency and high-frequency power increased within the first 5 minutes compared with baseline. Acute cigarette smoking alters HRV parameters, particularly within the first 5 to 10 minutes after smoking.     

Estrogen and the development and protection of nigrostriatal dopaminergic neurons: concerted action of a multitude of signals, protective molecules, and growth factors

The nigrostriatal dopamine system comprises the dopaminergic neurons located in the ventral midbrain, their axonal connections to the forebrain, and their direct cellular target cells in the striatal complex, i.e. GABAergic neurons. The major function of the nigrostriatal dopaminergic unit is the coordination and fine tuning of motor functions at the extrapyramidal level. Numerous biologically active factors including different types of growth factors (neurotrophins, members of the TGFbeta family, IGFs) and peptide/steroid hormones have been identified in the past to be implicated in the regulation of developmental aspects of this neural system. Some of these developmentally active determinants have in addition been found to play a crucial role in the mediation of neuroprotection concerning dopaminergic neurons. Estrogen was identified as such a compound interfering with embryonic neuronal differentiation and cell survival. The physiological mechanisms underlying these effects are very complex and include interactions with other developmental signals (growth factors), inflammatory processes as well as apoptotic events, but also require the activation of nonneuronal cells such as astrocytes. It appears that estrogen is assuming control over or at least influences a multitude of developmental and protective cellular mechanisms rather than taking over the part of a singular protagonist.     

Assessment of P wave duration and dispersion in Parkinson's disease

Cardiovascular disorders such as decreased heart rate variability, orthostatic hypotension, and arrhythmias have been frequently observed in Parkinson's disease (PD) patients. In this study, authors measured P wave duration and dispersion in PD patients and controls. Twenty-three consecutive patients with idiopathic PD and sex-age matched 23 control subjects were included to the study. A 12-lead surface ECG was obtained from each participant. Maximum-minimum P wave duration and P wave dispersion (PWD) were measured in both groups. Maximum P wave duration was found to be higher in PD patients than controls (117+/-12 vs. 105+/-9 ms p=0.001). Minimum P wave duration was similar in PD patients and controls (64+/-11 vs. 63+/-11 ms p=0.7). PWD in PD patients was also found to be higher than those of controls (53+/-11 vs. 43+/-10 ms p=0.0001). P wave duration and PWD did not significantly differ between PD patients taking anti-parkinsonian agents from those who were not (119+/-13 vs. 116+/-13 ms p=0.4 and 55+/-11 vs. 52+/-11 ms p=0.5, respectively). Moreover, when the PD patients taking anti-parkinsonian agents were excluded from the study, PD patients had still higher P wave duration and PWD compared to controls (119+/-11 vs. 105+/-9 ms p=0.004, 52+/-10 vs. 43+/-10 ms p=0.009, respectively). In conclusion, we found that P wave duration and PWD were greater in PD patients compared to control subjects.     

Neural cell adhesion molecule-180 expression as a prognostic criterion in colorectal carcinoma： Feasible or not？

AIM： To evaluate the frequency of neural cell adhesion molecule （NCAM）-180 expression in fresh tumor tissue samples and to discuss the prognostic value of NCAM-180 in routine clinical practice.
METHODS： Twenty-six patients （16 men, 10 women） with colorectal cancer were included in the study. Fresh tumor tissue samples and macroscopically healthy proximal margins of each specimen were subjected to flow-cytometric analysis for NCAM-180 expression.
RESULTS： Flow-cytometric analysis determined NCAM-180 expression in whole tissue samples of macroscopically healthy colorectal tissues. However, NCAM-180 expression was positive in only one case （3.84%） with well-differentiated Stage Ⅱ disease who experienced no active disease at 30 months follow-up.
CONCLUSION： As a consequence of the limited number of cases in our series, it might not be possible to make a generalisation, nevertheless the routine use of NCAM-180 expression as a prognostic marker for colorectal carcinoma seems to be unfeasible and not cost-effective in clinical practice due to its very low incidence.     

Predictive ability of fasting plasma glucose for a diabetic 2-h postload glucose value in oral glucose tolerance test: spectrum effect

The performance of diagnostic tests may vary according to patient characteristics. The aim of this study is to find out the factors, if any, that may affect the performance of fasting plasma glucose (FPG) to predict a diabetic 2-h postload glucose level (> or =200 mg/dl) in oral glucose tolerance test (OGTT). One hundred ninety-six patients with known risk factors for diabetes mellitus to whom OGTT was applied were included. Factors that may have an effect on the performance of FPG in prediction of a diabetic value in OGTT were determined by using logistic regression and likelihood ratios (LRs). The cutoff of FPG predicting a 2-h postload glucose of > or =200 mg/dl was calculated by receiver operating characteristic curve as 110 mg/dl (sensitivity, 76.7%; specificity, 75.9%). Waist-to-hip ratio (WHR) and body mass index (BMI) influenced sensitivity, whereas age, family history, and presence of hyperlipidemia affected specificity of FPG. Significant factors for positive LR were age and hyperlipidemia, whereas sex, smoking, hyperlipidemia, physical inactivity, WHR, and BMI influenced negative LR. Fasting plasma glucose performance as a diagnostic test can be affected by many factors that are clearly stated as risk factors for diabetes mellitus. These data emphasize how the interpretation of a diagnostic test varies as the patient characteristics vary; the criteria that we confidently rely on may not be that reliable, changing between just two different patients.     

Circulating adiponectin represents a biomarker of the association between adiposity and bone mineral density

An association exists between adiposity, insulin resistance, and osteoporosis; however, the mechanism of this relationship remains enigmatic. We aimed to determine whether the insulin resistance index (HOMA-IR), serum adiponectin, or leptin levels are associated with bone mineral density (BMD). A cross-sectional, observational study was designed. Eighty-four postmenopausal ambulant women [52.5 (50.0–58.0) years; body mass index (BMI): 29.4 (25.9–33.8) kg/m²] referred for osteoporosis screening were enrolled. Anthropometric measures, fasting serum adiponectin and leptin levels, and the HOMA-IR were determined. The relationships between these variables and lumbar, hip, and forearm BMD measured by dual-energy X-ray absorptiometry (DXA) were analyzed. Considering all 84 participants, the HOMA-IR index was 1.82 (1.17–2.86), serum adiponectin was 13.25 (10.49–16.88) μg/ml, and serum leptin was 19.26 (14.94–24.90) ng/ml. BMI, waist circumference, and leptin positively correlated with hip and lumbar BMD, whereas adiponectin negatively correlated. Multivariate analysis confirmed an inverse relation between serum adiponectin level and femoral neck and lumbar BMD measurements. In total hip and forearm areas, there was no independent association of adipocytokines with BMD measurements. Instead, waist circumference was independently associated with BMD measurements. In conclusion, adiponectin may represent a biomarker in the relationship between visceral fat mass and BMD. However, this association is probably confounded by the specific body composition parameters (i.e., waist circumference, BMI) in postmenopausal women.