Primary tumors and mediastinal lymph nodes after neoadjuvant concurrent chemoradiotherapy of lung cancer: serial CT findings with pathologic correlation

PURPOSE: The purpose of this work was to describe the changes of primary tumor and mediastinal lymph nodes on CT after neoadjuvant concurrent chemoradiotherapy and to correlate the CT findings with pathology. METHOD: Twenty-one consecutive patients [N2 disease (n = 19) or resectable T4 and N2 disease (n = 2)] with non-small cell lung cancer underwent neoadjuvant concurrent chemoradiotherapy. Changes of primary tumor and mediastinal nodes before and after the therapy were assessed using CT. The CT findings were correlated with pathologic findings. RESULTS: With neoadjuvant therapy, decrease in T stage was achieved in 9 of 21 (43%) patients on CT. On pathology, the remaining tumor consisted mostly of fibrosis and necrosis with little proportion of viable tumor cells (mean volume 17%, range 0-55%). Decrease in nodal stage was achieved in 14 of 21 (67%) patients on pathologic examination. Seven patients had cancer cells in mediastinal lymph nodes: in 6 of 9 (67%) patients with adenocarcinoma and 1 of 12 (8%) patients with squamous cell carcinoma (p = 0.016). CONCLUSION: With neoadjuvant concurrent chemoradiotherapy, the remaining tumor consists mostly of fibrosis or necrosis. Decreased nodal stage on pathology is achieved especially in patients with N2 disease of squamous cell carcinoma. The CT findings of the tumor and mediastinal nodes are not helpful in predicting the pathology after the therapy.     

"Bridging vascular sign" in the MR diagnosis of exophytic uterine leiomyoma

PURPOSE: The purpose of this study was to evaluate the usefulness of the "bridging vascular sign" in the diagnosis of an exophytic uterine leiomyoma and differentiation of a uterine leiomyoma from some other mass arising in the adnexa on pelvic MRI. METHOD: Of 52 women with a pelvic mass in whom pelvic MRI was performed to determine its origin, 26 women with surgicopathologically proven leiomyomas were included in this study. The other 26 women were proved to have indeterminate adnexal masses such as tuboovarian abscess, endometrioma, fibroma, etc. To obtain axial/ sagittal T2-weighted and pre-/postcontrast T1-weighted images, a 1.5 T unit was used. Positive bridging vascular sign was defined as the presence of curvilinear tortuous signal void vascular structures crossing and/or between the uterus and the pelvic mass. For the presence or absence of this sign, the percentages of patients in each group were calculated and compared. RESULTS: Bridging vascular sign was present in 20 (76.9%) of 26 cases of leiomyomas but in no cases of other adnexal masses. Only exophytic uterine leiomyomas had this sign. CONCLUSION: Bridging vascular sign on MRI may be a useful radiologic sign in the diagnosis and differentiation of an exophytic uterine leiomyoma from some other mass arising in the adnexa.     

The effects of sucrose on stability of human brain natriuretic peptide [hBNP (1–32)] and human parathyroid hormone [hPTH (1–34)]

Abstract: Although the effect of sucrose on the physical stability of proteins has been well documented, its impact on their chemical stability is largely unknown. The aim of this study was to investigate the potential effects of sucrose on the structural conformation of human brain natriuretic peptide [hBNP (1–32)] and the synthetic human parathyroid hormone [hPTH (1–34)], and link these effects to chemical degradation pathways of these peptides. The stability of hBNP (1–32) and hPTH (1–34) was studied at pH 5.5. Aggregation was monitored using size exclusion high‐performance liquid chromatography (SE‐HPLC), whereas oxidation and deamidation products were measured by reversed phase (RP) HPLC. Fourier transform infrared (FT‐IR) spectroscopy was used to study the peptides’ conformation. Sucrose retarded aggregation, deamidation, and oxidation of hBNP (1–32) and hPTH (1–34), with a maximum effect at relatively high concentrations (as much as 1 m ). FT‐IR spectroscopy indicated that sucrose maintained the native conformation of hBNP (1–32) and induced small conformation changes in the hPTH (1–34) structure. Sucrose enhanced the stability of hBNP (1–32) and hPTH (1–34) in liquid formulations. The stabilizing effect of sucrose was due to a large extent to retardation of oxidation and deamidation of hBNP (1–32) and hPTH (1–34).     

Imaging of malignant lymphomas with F-18 FDG coincidence detection positron emission tomography

PURPOSE: The authors evaluated the utility of F-18 fluorodeoxyglucose (FDG) coincidence detection (CoDe) positron emission tomography (PET) for staging, post-treatment evaluation, and follow-up assessment of patients with malignant lymphomas. MATERIALS AND METHODS: Fifty-eight patients with histologically proved malignant lymphomas (4 Hodgkin's disease, 54 non-Hodgkin's lymphoma) underwent CoDe PET using F-18 FDG. CoDe PET was performed using a dual-head gamma camera equipped with coincidence detection circuitry. Of the 87 CoDe PET studies, 26 were performed for staging, 38 for post-treatment evaluation, and 23 for follow-up evaluation of recurrence. The entire trunk, from the cervical to the inguinal regions, or selected regions were scanned with the patient in the supine position. No attenuation correction was made and reconstruction was performed using filtered back-projection rather than iterative reconstruction. CoDe PET findings were compared with corresponding results of computed tomographic (CT) and magnetic resonance imaging (MRI), tissue biopsy, or clinical follow-up. RESULTS: For staging, 52 sites were positive on CoDe PET or CT-MRI. CoDe PET detected 49 sites (94%), and CT-MRI showed 47 sites (90%). CoDe PET detected five more lymphomatous lesions and missed three lesions. For post-treatment evaluation, CoDe PET showed a positive predictive value of 100% and a negative predictive value of 83%, but the validated cases numbered only 11. For follow-up for recurrence, CoDe PET had a negative predictive value of 90%, but frequent false-positive findings were noted in the head and neck region as a result of underlying inflammatory changes. CONCLUSIONS: For staging, FDG CoDe PET alone without attenuation correction is not sensitive enough to be used as an independent imaging method, especially for small abdominal lesions. However, it appears to be an accurate method for assessing residual disease and for patient follow-up.     

Total sleep deprivation decreases immobility in the forced-swim test.

Sleep deprivation can exert antidepressant effects in humans in less than 24 h, making it the fastest acting antidepressant treatment. However, it is rarely used clinically because the effect disappears once the subject goes back to sleep. An understanding of the neurobiological mechanisms underlying the antidepressant effect of sleep deprivation should help to develop new rapidly acting antidepressant strategies. In the present report, an animal model of depression (the forced-swim test) was used to determine whether the effects of total sleep deprivation parallel those obtained with antidepressant drugs. Using the disk-over-water method, rats deprived of sleep for 24 h exhibited increased swimming behavior when compared to cage control rats, mimicking the effects of serotonergic antidepressants. After 48 h, sleep-deprived rats exhibited increased swimming when compared to both cage control and stimulus control rats, demonstrating that the effect is due to sleep deprivation per se, and not to extraneous factors inherent in the sleep deprivation protocol (such as stress and movement). We believe that this paradigm can be used to study the neurobiological mechanisms of rapid antidepressant effects induced by sleep deprivation.     

Enhanced paclitaxel bioavailability after oral administration of paclitaxel or prodrug to rats pretreated with quercetin.

The aim of this study was to investigate the effect of quercetin on the bioavailability of paclitaxel after the oral administration of paclitaxel or a prodrug to rats pretreated with quercetin. Paclitaxel (40 mg/kg) and prodrug (280 mg/kg, 40 mg/kg as the paclitaxel) were administered orally to rats pretreated with quercetin (2, 10, 20 mg/kg). The plasma concentrations of paclitaxel pretreated with quercetin were increased significantly (P < 0.01 for paclitaxel; P < 0.05 for prodrug) compared to the control. The areas under the plasma concentration-time curve (AUC) and the peak concentrations (Cmax) of paclitaxel pretreated with quercetin were significantly higher (P < 0.01) than the control. The half-life (t(1/2)) and mean residence times were significantly (P < 0.05) longer compared to the control. The absolute bioavailability (AB%) of paclitaxel pretreated with quercetin was significantly higher (P < 0.01) than the control. The AUC of paclitaxel after administration of the prodrug to rats pretreated with quercetin was significantly (P < 0.05) higher than the prodrug control. The relative bioavailability of paclitaxel after administration of the prodrug to rats pretreated with quercetin was 1.25- to 2.02-fold higher than the prodrug control. The AB% of paclitaxel was increased significantly (P < 0.05) by quercetin from 8.0 to 10.1 and 16.2%. The bioavailability of paclitaxel administered as a prodrug with or without pretreatment of quercetin was remarkably higher than the control. AUC, AB% and Cmax of paclitaxel after administration of the paclitaxel or prodrug pretreated with quercetin for 3 days were much higher than those administered after 20 min. It might have resulted from the physicochemical properties of the prodrug, which is a water-soluble compound and passes through the gastrointestinal mucosa more easily than paclitaxel without obstruction of P-gp and cytochrome P-450 in the gastrointestinal mucosa. It seems that the development of oral paclitaxel preparations as a prodrug or with quercetin is feasible, which is more convenient than the i.v. dosage forms.     

Clinical experience with ceramics in total hip replacement

As part of a search for better articulation in total hip prostheses, the decrease in the thickness of the socket in different total hip prostheses was measured in vivo. The wear rates of (1) RCH 1000 (molecular weight, 10(6)) socket gamma-irradiated with 100 Mrad articulating with a crude COP (stainless steel containing 20% cobalt and 0.01% phosphorous) metal femoral head; (2) RCH 1000 socket nonirradiated articulating with a crude COP femoral head; (3) RCH 1000 socket irradiated with 100 Mrad articulating with an alumina femoral head; (4) ultra high molecular weight polyethylene (molecular weight, 5-6 x 10(6)) socket articulating with an alumina femoral head; and (5) ultrahigh molecular weight polyethylene socket articulating with a stainless steel femoral head (T-28) were 0.06, 0.30, 0.06, 0.1 and 0.25 mm/year, respectively, in the authors' clinical cases. Alumina femoral heads were effective in decreasing wear of the polyethylene socket. However, the wear rates of gamma-irradiated sockets articulating with alumina and with metal femoral heads wear very low and were not different from each other. Regarding the relationship between wear rate and the thickness of the ultra high molecular weight polyethylene socket articulating with a 28 mm alumina femoral head, on radiographs, average wear rates of socket thicknesses of 7, 8, 9, 10 and 11 mm were 0.14, 0.15, 0.12, 0.06, and 0.08 mm/year, respectively. On measuring retrieved prostheses, average wear rates of 7, 8, 9 and 11 mm thickness sockets were 0.2, 0.19, 0.14, and 0.1 mm/year, respectively. The wear of sockets has been proven to be minimal in alumina femoral heads articulating with ultrahigh molecular weight polyethylene sockets thicker than 10 mm.     

Larynx preservation surgery in pyriform sinus cancer

As a general rule, surgery, whenever possible followed by irradiation, is considered to be a standard treatment for pyriform sinus cancer. In early primary lesions, many different approaches have been tried for larynx preservation. From 1990-1997, 7 patients with pyriform sinus carcinoma without the involvement of pyriform sinus apex were treated with partial laryngopharyngectomy at the Asan Medical Center. Three patients were T1 stage and four were T2. All patients had nodal metastases and were treated with neck dissection and postoperative radiotherapy. Follow-up period was 1-8 years. One regional recurrence and one distant metastasis occurred; however, there was no recurrence at the primary site. The voices of all the patients were saved. The most uncomfortable postoperative symptom was mild aspiration. From these results, we can conclude that partial laryngopharyngectomy with neck dissection might be the favorable treatment modality for selected cases of pyriform sinus cancer.     

Psoas abscess: diagnostic and therapeutic considerations in six patients

Psoas abscess (PA) is an infrequent clinical entity and presents diagnostic and therapeutic challenges. Six cases are reported concerning diagnostic and therapeutic considerations. Clinical diagnosis is difficult because of non-specific symptoms. The primary psoas abscess has no definite etiology and is spread by hematogeneous route from a distant occult site. The PA can also be secondary to gastrointestinal pathology through direct infection of adjacent structures. The most common causes are Crohn's disease, appendicitis, diverticulitis and carcinoma. Routine laboratory evaluation is seldom useful for localizing the disease process. Conventional radiological techniques are often unhelpful. Modern imaging diagnosis techniques such as ultrasound and computerized tomography have allowed for a refinement in both the etiologic diagnosis and the treatment by means of CT-guided or ultrasound-guided percutaneous drainage of the abscess, thus avoiding surgical drainage in many cases. Immediately on diagnosis of PA prompt treatment is necessary. Percutaneous drainage should be performed whenever possible and in case of failure, surgical drainage should be practiced as well as intestinal resection, whenever indicated.