Nonseminomatous germ cell testicular tumors clinical stage I: differentiated therapeutic approach in comparison with therapeutic approach using surveillance strategy only

Surveillance after orchiectomy alone becomes popular for the management of clinical stage I nonseminomatous germ cell testicular tumors (CS I NSGCTT). Effort to identify patients at high risk of relapse leads to searching for risk factors of CS I NSGCTT. The aim of the study was to analyse own long-term experiences with different therapeutic approaches in CS I NSGCTT patients according to risk factors of the disease progression and to correlate these results with the group of patients who were treated with surveillance strategy only. From 11/1984 to 12/1991 a total of 145 patients with CS I NSGCTT were treated with surveillance strategy only (group A) and were followed-up to 1/2007. Patients, who had the disease progression, were treated with systemic chemotherapy. The disease progression was experienced in 52 patients (35.9 %). The overall survival rate of the patients in this group was 130/145 (89.7 %). From 1/1992 to 1/2007 a total of 323 patients with CS I NSGCTT were stratified to different risk-adapted therapeutic approaches (groups B1-3) according to histopathologic findings of primary tumor removed by inguinal orchiectomy. 111 patients (group B1) with vascular invasion and majority of embryonal carcinoma component in the primary tumor were treated with adjuvant chemotherapy (2 cycles of BEP). Disease progression developed in two patients (1.9 %). Other patients live without evidence of disease (NED). None of them died. Among 11 patients (group B2) with vascular invasion and majority with teratomatous elements in the primary tumor underwent primary retroperitoneal lymph node dissection (RPLND), 9 were found to be pathological stage I. The disease progression was observed in two patients (18.2 %), they died 87-122 months following orchiectomy. Two patients (18.2 %) with pathological stage II received adjuvant chemotherapy. Other 7 patients live with NED following RPLND. 201 patients (group B3) without vascular invasion have been followed after orchiectomy alone. They were kept under close surveillance, consisting of regular follow-up with tumor markers, chest x-ray and CT of the retroperitoneum. The disease progression was observed in 39 patients (19.4 %), who were treated with BEP chemotherapy. Three of them (7.7 %) died after a mean follow-up of 32.7 months following orchiectomy. The overall survival rate of all patients in group B1-3 was 98.4 %. Introduction of different therapeutic approaches in CS I NSGCTT patients according to risk factors of the disease progression might reduce the overall relapse rate of these patients from 35.9 % (group A) to 19.4 % (group B3) (P< 0.001). Surveillance procedure is recommended only in patients without vascular invasion in the primary tumor.     

Breast MR imaging with loop-gap resonators

Breast images obtained at 1.5 T using a loop-gap resonator pair as both the excitation and detection device are presented. The efficiency of this approach is high, as judged by the low level of radio frequency (RF) power required to obtain a 90 degree pulse and the uniformity of the RF field within the resonator pair. A modification of the pair geometry provides for reasonable observation of the tissues through the chest wall and laterally to the axillae.     

MR fat suppression technique in the evaluation of normal structures of the knee

The chopper fat suppression (CFS) pulse sequence, which is a phase sensitive implementation of the Dixon fat suppression method and the spin echo (SE) pulse sequence, was used in the evaluation of anatomic structures of the normal knee using 48 sets of imaging sequences in six volunteers using a repetition time/echo time combination of 1,500/30, 60 ms. A demonstration of the CFS technique in 10 patients with suspected knee pathology is also presented. A semiquantitative grading scale was established to rate anatomic visualization and used to compare CFS and SE pulse sequence techniques. The results in normal subjects demonstrate that hyaline cartilage is significantly better visualized by fat suppression pulse sequence than by conventional SE pulse sequence in the coronal and sagittal planes of imaging (p less than 0.001). The preliminary results from patients studies suggest that CFS imaging may be useful in the evaluation of meniscal tears, in the differentiation of hyaline cartilage from joint fluid, and in the detection of both soft tissue and bone injuries.     

Magnetic field mapping

Homogeneous radiofrequency magnetic fields are necessary for production of high-quality magnetic images and for most forms of magnetic resonance spectroscopy. It is often convenient to map the radiofrequency homogeneity associated with a resonant device by measuring the magnetic image intensity of an aqueous phantom placed within the resonator. The rf field intensity is not related trivially to the magnetic image intensity, and the relationship is different for different image acquisition methods. In this report relationships between rf field intensity and magnetic image intensity are derived and radio-frequency field maps presented for comparison using (1) an rf probe moved about within the resonant volume, (2) spin-echo images, and (3) small tip angle gradient refocused echo images.     

Spin-lattice relaxation time measurements using hybrid CSI--phantom study

The spin-lattice relaxation time T1 of multicomponent tissues is often determined by fitting relaxation data to monoexponential functions. This process can lead to large errors in the relaxation time. We describe a procedure using chemical-shift imaging (CSI) which separates the NMR signal into water and lipid components thus allowing the two signals to be individually analyzed for relaxation times. This procedure yields more representative relaxation times than those obtained by both monoexponential and biexponential fitting schemes.     

Emotion-related learning in patients with social and emotional changes associated with frontal lobe damage.

A group of patients with damage to the ventral part of the frontal lobes was severely impaired relative to a group of patients without damage in this area (the non-ventral group) in the reversal and in the extinction of simple visual discrimination tests. In these tests they continued to make responses to a previously rewarded stimulus. Patients often reported verbally that the contingencies had changed, but were unable to alter their behaviour appropriately. These impairments occurred independently of IQ or verbal memory impairments. The perseverative touching of a previously rewarded stimulus is consistent with work with non-human primates showing impaired reversal and extinction after orbitofrontal lesions. Performance on these reversal and extinction tests was highly correlated with scores obtained on a behaviour questionnaire, which reflected the degree of disinhibited and socially inappropriate behaviour exhibited by patients. It is suggested that a difficulty in modifying responses, especially when followed by negative consequences, as manifested in these simple laboratory tests, may contribute to the inappropriate behaviour shown in daily life by patients with frontal lobe damage.     

Targeting structural flexibility in HIV-1 protease inhibitor binding

HIV-1 protease remains an important anti-AIDS drug target. Although it has been known that ligand binding induces large conformational changes in the protease, the dynamic aspects of binding have been largely ignored. Several computational models describing protease dynamics have been reported recently. These have reproduced experimental observations, and have also explained how ligands gain access to the binding site through dynamic behavior of the protease. Specifically, the transitions between three different conformations of the protein have been modeled in atomic detail. Two of these forms were determined by crystallography, and the third was implied by NMR experiments. Based on these computational models, it has been suggested that binding of inhibitors in allosteric sites might affect protease flexibility and disrupt its function.