Spatial interactions in perceived speed

Previous research has shown that the perception of motion within a local region is influenced by other motions within neighboring areas (eg induced motion). Here, a study is reported of the perceived speed of dots moving within a circular target region, which was surrounded by other motions within a larger surrounding area. The perceived speed of the central dots was found to be fastest when the surround was stationary; it became slower as the speed of motion in the surround was increased. This decrease in the perceived target speed with increases in surround velocity occurred regardless of whether the direction in which the surround moved was the same as or opposite to the motion of the target region. This result cannot be explained by using simple models of perceived speed that depend only upon such factors as the magnitude of relative motion between center and surround. The spatial area over which these motion interactions occur was also investigated.     

High frequency of two mutations in codon 778 in exon 8 of the ATP7B gene in Taiwanese families with Wilson disease

The gene for Wilson disease (WD) has been cloned as a P type copper transporter gene (ATP7B). To elucidate the possible genetic mechanism for the diversity of clinical manifestations, we characterised 22 Taiwanese families with WD by microsatellite haplotyping of close DNA markers D13S314-D13S301-D13S316. We also screened for mutations of codon 778 in the transmembrane region. There were at least 15 haplotypes within eight broad subgroups observed among 44 WD chromosomes. Among the 22 unrelated patients, we found that six patients (27%) carried a codon 778 mutation. Nucleotide sequence analysis showed there were two different mutations: the previously reported Arg778Leu mutation in four patients and Arg778Gln, a new mutation, in two patients. The two different mutations of the same codon occurred in two distinct microsatellite haplotypes.     

Infrequent alterations of the RAR alpha gene in acute myelogenous leukemias, retinoic acid-resistant acute promyelocytic leukemias, myelodysplastic syndromes, and cell lines

Retinoids are important regulators of cell growth and differentiation in vitro and in vivo and they exert their biologic activities by binding to nuclear retinoic acid receptors (RARs; alpha, beta, and gamma) and retinoid X receptors (RXRs; alpha, beta, and gamma). All-trans retinoic acid (RA) induces complete remission in patients with acute promyelocytic leukemia (APL) presumably by binding directly to RAR alpha of APL cells. Leukemic blasts from APL patients initially responsive to RA can become resistant to the agent. HL-60 myeloblasts cultured with RA have developed mutations of the ligand-binding region of RAR alpha and have become resistant to RA. Furthermore, insertion of an RAR alpha with an alteration in the ligand-binding region into normal murine bone marrow cells can result in growth factor-dependent immortalization of the early hematopoietic cells. To determine if alterations of the ligand binding domain of RAR alpha might be involved in several malignant hematologic disorders, the mutational status of this region (exons 7, 8, and 9) was examined in 118 samples that included a variety of cell lines and fresh cells from patients with myelodysplastic syndromes (MDS) and acute myeloid leukemias (AML), including 20 APL patients, 5 of whom were resistant to RA and 1 who was refractory to RA at diagnosis, using polymerase chain reaction-single-strand conformational polymorphism (PCR-SSCP) analysis and DNA sequencing. In addition, 7 of the 20 APLs were studied for alterations of the other coding exons of the gene (exons 2 through 6). No mutations of RAR alpha were detected. Although the sensitivity of PCR-SSCP analysis is less than 100%, these findings suggest that alterations of RAR alpha gene are rare and therefore other mechanisms must be involved in the onset of resistance to retinoids and in the lack of differentiation in disorders of the myeloid lineage.     

Transnasal approach to the orbit, the interorbital space, and the nasopharynx

We present a surgical procedure that provides exposure to the medial part of the orbit, the interorbital space, and the nasopharynx. A midline incision of the nose is followed by a pedicled osteotomy of the lateral nasal wall and the medial wall of the orbit in one piece. This transnasal approach provides good exposure to the medial parts of the craniofacial junction to remove foreign bodies or benign tumors.     

Thermosensitive stent (Memotherm) for the treatment of benign prostatic hyperplasia

Recently, more and more alternative therapeutic methods have been used for the treatment of benign prostatic hyperplasia (BPH). We will report on therapeutic results with a new thermosensitive stent system (Memotherm). This wire mesh stent has been designed especially for urological purposes. It is made of Nitinol, a thermoreactive material, and gains its maximum expansion force al body temperature. Due to the properties of the material the stent is flexible and can adapt to the anatomical conditions of the prostatic part of the urethra. Because of individual variations in the length of the prostatic part of the urethra, the system is available in lengths from 2 to 8 cm. The knitted structure for the first time allows atraumatic removal. Between April, 1992, and September, 1993, we treated a total of 54 BPH patients with the stent system. Mean patient age was 76.1 +/- 7.6 years (61-98). Mean prostatic volume was 51.9 +/- 25 ml (20-150), and the length of the applicated stents was 32.3 +/- 9.5 mm (20-70). Patient selection for stent treatment was carried out with regard to the preoperative risk status of this patient group. Fourteen (26%) of the patients treated were able to micturate before operation; in 40 (74%) urinary drainage was accomplished by means of an indwelling catheter. Following stent application, 53 out of 54 patients were able to micturate. With the first group (preoperative voiding ability), maximum flow had increased from 4.5 ml/s to a mean of 15.8 ml/s, while residual urine volume had decreased from 194.4 ml to 11.8 ml and the AUA 6 Symptoms Score had improved from 24 points to 3.5 points 6 months after stent application. All differences were statistically significant (P < 0.02). With the second group (no preoperative voiding ability), the AUA 6 Symptoms Score had improved from 25 points to 3.9 points (P < 0.02) 6 months after the operation, at which time the mean maximum flow rate was 14.8 ml/s and residual urine volume 14.8 ml. There was no statistically significant difference between the patients who were able and those who were unable to micturate before operation. One case of epididymitis was the only major complication observed after stent placement. Frequent urgency symptoms (30 out of 54 patients; 55.5%) subsided after a mean period of 1 week. The Memotherm stent offers an interesting therapeutic alternative for BPH risk patients.     

Renal artery stent placement: long-term results with the Wallstent endoprosthesis

PURPOSE: To evaluate clinical success and long-term patency of a Wallstent in the renal artery. MATERIALS AND METHODS: Twenty-five Wallstents were placed in 21 patients to treat delayed restenosis after previous balloon angioplasty (n = 13) or inadequate immediate postangioplasty response (n = 8). Indications for angioplasty were hypertension in all patients and renal preservation in seven. Stenosis was atheromatous in 15 patients, involving ostium in seven. RESULTS: Stent placement was successful in all patients. At follow-up angiography (range, 12-60 months), four patients (20%) had stent restenosis. Of these, three had undergone treatment for restenosis after angioplasty and three had ostial lesions. Cumulative primary patency rate was 95%, 85%, and 77% at 7, 9, and 15 months, respectively. Hypertension was cured in three patients and improved in 18. CONCLUSION: Arterial stent placement has good clinical results and high long-term patency rates after conventional renal angiography or delayed restenosis, especially in ostial lesions.     

Selective peripheral denervation for the treatment of spasmodic torticollis

The results of selective peripheral denervation in 50 patients with spasmodic torticollis are presented. Of our patients, 76% reported a significant improvement or disappearance of their dystonia. The mean follow-up is 25 months. There were no major side effects. We recommend the procedure to patients who primarily have responded to botulinum toxin therapy and had become secondary nonresponders or to those refusing further injections while still responding. The results are much less promising in patients who are primary nonresponders to botulinum toxin. Some remarkable histological findings are presented. The posterior branches of the cervical roots frequently showed signs of severe compression neuropathy. In three cases, a functional motor nerve regeneration was proved. Among all surgical options, selective peripheral denervation provides the best result and has the fewest side effects.     

A comparison of human papillomavirus detection rates by dot blot assay from smear and biopsy specimens with regard to human papillomavirus type and histologic diagnosis

Colposcopic biopsy and cervical smear sampling techniques for human papillomavirus (HPV) DNA dot hybridization were compared to reveal differences related to the level of the histopathologic detection of HPV type 16. The authors used a previously published dot blot assay to analyze 814 pairs of concurrent biopsy and smear DNA specimens for the presence of DNA of HPV 6, 11, 16, and 18. The overall HPV detection rate was 38%, the most prevalent type being HPV 16 (39% of all HPV-positive cases). In detection and typing of HPV DNA, a 81% concordance (658 of 814 pairs) was noted between the smear and biopsy specimens, with a significant correlation in detection of any of the HPV types in the specimens (kappa, .609). The rate of smear-negative cases among all biopsy-positive cases was similar for HPV 11 and HPV 16 (41% and 42%, respectively). Further analysis of distribution of the smear-negative and biopsy-positive cases among different histopathologic levels of disease showed no significant difference between neoplastic and nonneoplastic lesions for either virus type. In 56 cases, only the smear specimen was positive for DNA of the studied HPV types. Both biopsy and smear specimens should be used for HPV detection in cervical dysplasias.     

Isolation of Listeria monocytogenes in slaughter animals and bats of Togo (West Africa)

Listeria monocytogenes was isolated from the intestinal lymph nodes of 8 out of 342 apparently healthy slaughter animals at the municipal abattoir in Lome (Togo) and from the faeces of 3 out of 236 bats. Except two strains of serovar 4b isolated from bats, all the nine others belonged to serovar 1/2a. The positive findings of slaughter animals were made from the carcasses of 2 pigs, 5 little ruminants and 1 cattle. The findings are discussed in the light of present knowledge on the occurrence of L. monocytogenes in some species of animals and its implications for the human being.     

疏松砂层微粒运移特征及对油井动态的影响

微粒运移伤害是疏松产层一种比较普遍又相当严重的地层伤害。本文着重讨论了水动力作用下孔隙微粒运移条件，结合室内实验分析了不同类型的驱动流体对运移产生的影响，最后应用实际生产数据对比分析了冀东油田馆陶组产层微粒运移伤害后油井的几种典型动态特征。