Pierre Arthur Rocmans

Ploidy level and proliferative activity measurements in a series of 407 thyroid tumors or other pathologic conditions

This study describes the ploidy level and proliferation rate in a series of 74 multinodular goiters (MNGs), 17 cases of Hashimotos disease, 33 cases of Basedows disease, 113 adenomas, 139 primary carcinomas, and 31 cervical lymph node metastases from 376 patients. Both ploidy level and proliferation rate were assessed by digital cell image analyses of Feulgen-stained nuclei from formalin-fixed, paraffin-embedded tissues. The ploidy level of each sample was assessed using both its DNA index and its DNA histogram type. The proliferation index assessments corresponded to the determination of the proportion of cells in the S-phase fraction. The data reveal that the proportion of aneuploid cases increases according to the following sequence: simple MNGs and normomacrovesicular adenomas-->MNGs with adenomatous hyperplasia and microvesicular adenomas and Hürthle cell adenomas-->papillary and Hürthle cell carcinomas-->follicular and medullary carcinomas-->anaplastic carcinomas. This suggests the preneoplastic nature of the microvesicular adenomas and even of MNGs with adenomatous hyperplasia. The ploidy levels of 99% of the 407 cases of the thyroid tumor series could be described using six DNA histogram types: diploid, hyperdiploid, triploid, hypertriploid, tetraploid, and polymorphic. It was possible to assess the proliferation rate of 279 samples. The results show that a significantly higher proportion of malignant compared with benign thyroid tumors (35.5% v 10.5%, respectively) exhibited a proliferation index higher than 5%, and that, whether benign or malignant, the hypertriploid thyroid tumors proliferated significantly less than the nonhypertriploid thyroid tumors.

Respiratory Mechanics and Gas Exchange During One-Lung Ventilation for Thoracic Surgery: The Effects of End-Inspiratory Pause in Stable COPD Patients

OBJECTIVE To examine the effects of end-inspiratory pause (EIP) of different durations on pulmonary mechanics and gas exchange during one-lung ventilation (OLV) for thoracic surgery. DESIGN A prospective clinical study. SETTING A university hospital. PARTICIPANTS Eleven patients undergoing elective pulmonary resection with pulmonary hyperinflation on their preoperative pulmonary function studies. INTERVENTIONS Patients were anesthetized, paralyzed, and intubated with a double-lumen endotracheal tube. Their lungs were ventilated with a Siemens 900C ventilator (Siemens; Solna, Sweden), with constant inspiratory flow. Tidal volume, respiratory rate, and inspiratory time were kept constant during the study. MEASUREMENTS AND RESULTS During one-lung ventilation in the lateral decubitus position, three levels of EIP (0%, 10%, and 30%) were applied to the dependent lung in random order. After 15 minutes on the given ventilatory pattern, end-inspiratory and end-expiratory occlusions of at least 5 seconds were performed to obtain respiratory mechanics data. Arterial blood gas samples were drawn to assess gas exchange. Altering the duration of end-inspiratory pause from 0% to 30% resulted in a significant increase in intrinsic positive end-expiratory pressure (PEEPi) from 4.1 cm H2O to 7.0 cm H2O. Arterial oxygenation was significantly decreased from 109.7 to 80.5 mmHg and there was a significant negative correlation between the value of partial pressure of arterial oxygen (PaO2) and PEEPi by altering the duration of end-inspiratory pause. From the preoperative pulmonary function studies, the value of functional residual capacity (FRC) (% predicted) showed a significant negative correlation with the PaO2 changes. Partial pressure of arterial carbon dioxide (PaCO2) was not altered significantly by increasing the duration of end-inspiratory pause. CONCLUSION During the period of OLV in the lateral position of patients with preexisting pulmonary hyperinflation, the magnitude of PEEPi increased and oxygenation decreased significantly, whereas the efficacy of ventilation was not changed by the addition of an end-inspiratory pause to the ventilatory pattern. Because arterial oxygenation is affected by the presence of pulmonary hyperinflation, the method of ventilation should take into account the magnitude of preoperative pulmonary hyperinflation.

The influence of l-triiodothyronine, l-thyroxine, estradiol-17β, the luteinizing-hormone-releasing hormone, the epidermal growth factor and gastrin on cell proliferation in organ cultures of 35 benign and 13 malignant human thyroid tumors

Purpose: To characterize the influence of six factors on human thyroid tissues at the cell-proliferation level. These six factors were the epidermal growth factor (EGF), the luteinizing-hormone-releasing hormone (LHRH), triiodothyronine, thyroxine, estradiol and gastrin. Methods : Forty-eight human thyroid specimens were obtained from surgical resection and maintained alive for 48 h ex vivo (in vitro) under organotypic culture conditions. These specimens comprised 35 benign cases (17 multinodular goiters and 18 adenomas) and 13 cancers. Cell proliferation in the control and treated conditions (at a 5 nM dose) was assessed by means of the thymidine labeling index, which enables the percentage of cells in the S phase of the cell cycle to be determined in accordance with autoradiographic procedures. Results: The results show that, of the six factors tested here, EGF significantly (P < 0.05 to P < 0.001) increased cell proliferation in the greatest number of cancers as compared to what happened with the remaining five. Each of these six factors significantly increased or decreased proliferative cell activity in some 10%–30% of the cases under study. Conclusions: Triiodothyronine, thyroxine, LHRH and gastrin may increase or decrease cell proliferation in human thyroid tissues, whether benign or malignant, to the same extent as other hormones and/or growth factors such as thyrotropin, EGF, insulin-like growth factor 1, transforming growth factor β1 and estradiol the effects of which on thyroid cell proliferation are already well documented in the literature.