Ankle arthroplasty by excision of the talar body: subtotal talectomy

Giant platelet disorders (GPD) refer to rare, usually inherited states characterized by abnormally large platelets, thrombocytopenia and bleeding tendency of variable severity. This review summarizes major clinical and laboratory features of three GPDs (Bernard-Soulier syndrome, May-Hegglin anomaly and gray platelet syndrome). Differential diagnosis between immunological thrombocytopenia and GPDs is important. Although rare, giant platelet disorders should be borne in mind, since bleeding tendency in some individuals may be severe and knowledge of bleeding diathesis is of importance before delivery or surgical procedures also in less symptomatic individuals.     

Relationship between mandibular position and the coordination of masseter muscle activity during sleep in humans

Although bruxism has been regarded as having a possibly important role in the aetiology of craniomandibular disorders, the activity of masticatory muscles relative to mandibular position during sleep grinding as recorded by electromyography (EMG) has not yet been clarified. Surface EMGs of the bilateral superficial masseter muscles were recorded simultaneously with mandibular position during sleep from 12 volunteers for three consecutive nights. The incidence of two mandibular positions were recorded with magnetic sensors for both left- and right-sided mandibular grinding. One of the mandibular positions was the canine edge-to-edge position, and the other was the midpoint between the intercuspal position and the canine edge-to-edge position. The mode of the working/ balancing activity ratio ranged from 1/10 to 2/10, showing the marked predominance of balancing side masseter muscle activity during sleep grinding. During sleep grinding, EMG bursts of masseter muscle were observed mainly with mediotrusive mandibular movement from the canine edge-to-edge position. From the results of the present study, it is suggested that muscular dynamics during sleep are unique compared to that during voluntary clenching, and exert a greater mechanical load to the balancing side temporomandibular joint.     

Radiation myelopathy: a clinicopathological study with special reference to correlation between MRI findings and neuropathology

We describe magnetic resonance imaging (MRI) and neuropathological findings in a patient with chronic progressive radiation myelopathy (CPRM). An 81-year-old man with esophageal cancer underwent radiotherapy. Four years later he developed a progressive neurological deficit below the irradiated level of the spinal cord. Neurological examination revealed spastic paraplegia. MRI findings showed an area of high signal intensity on T2-weighted images of the thoracic spinal cord. On the basis of clinical and MRI findings, we diagnosed his condition as CPRM. MRI performed thirteen months after onset of neurological signs revealed mild atrophy of the spinal cord detected on T1-weighted images and an area of high signal intensity within the spinal cord detected on T2-weighted images. Neuropathological examination revealed findings consistent with radiation myelopathy. We speculate that the area of high signal intensity within the spinal cord detected on T2-weighted images might be a result of proliferation of small vessels, which was discovered upon autopsy.     

A 32 kbyte integrated cache memory

The system, circuit, layout and device levels of an integrated cache memory (ICM), which includes 32 kbyte DATA memory with typical address to HIT delay of 18 ns and address to DATA delay of 23 ns, are described. The ICM offers the largest memory size and the fastest speed ever reported in a cache memory. The device integrates a 32 kbyte DATA INSTRUCTION memory, a 34 kbit TAG memory, an 8 kbit VALID flat, a 2 kbit least recently used (LRU) flag, comparators, and CPU interface logic circuits on a chip. The inclusion of the DATA memory is crucial in improving system cycle time. The device uses several novel circuit design technologies, including a double-word-line scheme, low-noise flush clear, a low-power comparator, noise immunity, and directly testable memory design. Its newly proposed way-slice architecture increases both flexibility and expandability     

Preparation of carboxylate groups-containing thin films by plasma polymerization

Summary Plasma polymerization in a mixture of acrylic acid and carbon dioxide (CO₂) gas was investigated. The polymer deposition rate in plasma polymerization of acrylic acid increased by admixing CO₂ gas, and polymers containing carboxyl groups were formed. The amount of carboxyl groups alterable to carboxylate anions by treating with 0.1 N KOH solution or NH₃ gas reached twice of that formed in plasma polymerization without CO₂ gas.     

Hepatic parenchymal hyperperfusion abnormalities detected with multisection dynamic MR imaging: appearance and interpretation

On arterial-dominant-phase images in multisection dynamic MR imaging, early-enhancing areas that are perfusion abnormalities rather than tumor deposit are sometimes encountered. The purpose of this article was to determine the frequency, location, and appearance of these hepatic parenchymal hyperperfusion abnormalities and to discuss possible causes of these abnormalities. Multisection dynamic MR images obtained in 415 patients with suspected hepatobiliary diseases were reviewed for the presence of hyperperfusion abnormalities. A total of 96 hyperperfusion abnormalities were identified in 88 (21%) of 415 patients. They were characterised from their shape, distribution, or location as lobar or segmental (n = 36 [38%]), subsegmental (n = 32 [33%]), or subcapsular (n = 28 [29%]) hyperperfusion abnormalities. Presumable etiologies were considered as follows: (a) compression, obstruction, or ligation of the portal vein; (b) siphoning effect by tumor; (c) aberrant cystic venous drainage; (d) percutaneous ethanol injection; (e) percutaneous needle biopsy; (f) rapid drainage by the subcapsular vein; or (g) cirrhosis or unknown. A significant percentage of patients had hepatic hyperperfusion abnormalities. Familiarity with these hyperperfusion abnormalities on multisection dynamic MR images is important to prevent false-positive diagnoses.     

A coding theorem for lossy data compression by LDPC codes

In this article, low-density parity-check (LDPC) codes are applied to lossy source coding and we study how the asymptotic performance of MacKay's (see ibid, vol.45, p.399-431, Mar. 1999 and vol.47, p.2101, July, 2001) LDPC codes depends on the sparsity of the parity-check matrices in the source coding of the binary independent and identically distributed (i.i.d.) source with Pr{x=1}=0.5. In the sequel, it is shown that an LDPC code with column weight O(logn) for code length n can attain the rate-distortion function asymptotically.     

A GaAs-based field-modulating plate HFET with improved WCDMA peak-output-power characteristics

A novel GaAs power FET with a field-modulating plate (FP-FET) and operated at a drain bias voltage of 24 V was developed. Regarding the power performance of an FP-FET under wideband code division multiple access (WCDMA) operation, its peak output power significantly degraded in the saturated-output-power region when its FP length was short. However, by introducing a sufficiently large FP length, it was demonstrated that the peak-power degradation can be significantly suppressed. In particular, an FP-FET amplifier fabricated with an FP length of 1.5 /spl mu/m exhibited no WCDMA peak-power degradation and delivered an output power of 120 W with a linear gain of 14.2 dB at 2.14 GHz.     

Evaluation of the radiosensitizing effects of RK28 intravenous, intraarterial, and intratumoral injections on the rabbit VX2 tumor system

PURPOSE: To evaluate the differences in the radiosensitizing effects of intravenous (i.v.) injection, intraarterial (i.a.) injection, and intratumoral (i.t.) injections of the hypoxic cell radiosensitizer RK28 ([1-(4'-hydroxy-2'-butenoxy)methyl-2-nitroimidazole], a 2-nitroimidazole with an acyclic sugar analogue substituted at the N-1 position of the imidazole ring) using an animal experimental system. METHODS AND MATERIALS: Rabbit VX2 tumors, which were implanted in the muscle of left hind legs and grown to 3 cm in diameter, were treated with RK28 (80 mg/kg x b.wt.) before 15 Gy of local x-ray irradiation. The auricular vein and the left saphenous artery were used for systemic injection and regional injection, respectively. For i.t. injection, a 21-gauge needle with three lateral holes was positioned in the central area of the tumor. Tumor regression was precisely evaluated by computed tomograpy (CT), and survival time was also studied. Using high-performance liquid chromatography (HPLC), pharmacokinetic studies for RK28 and its seven major metabolites were performed in tumor and serum at 0, 10, 20, 30, and 60 min after drug injection was completed. RESULTS: Radiosensitizing effects of RK28 were considered present after i.a. injection (p < 0.05) and i.t. injection (p < 0.05) after analyzing tumor volumes on day 21 after treatment. Increased survival was not observed in any group with RK28 injection compared with survival in the group treated by x-ray irradiation alone. Pharmacokinetic studies showed the average concentration of RK28 in the tumor during x-ray irradiation was 1.3 times higher after i.a. injection and 3.5 times higher after i.t. injection than that after i.v. injection. The time modifying factor50 (TMF50: ratio of time for tumor to decrease by 50%, radiation alone vs. radiation plus drug) was calculated to be 1.5 after i.v. injection, 1.7 after i.a. injection, and 2.3 after i.t. injection. The values of TMF50 correlated to the average concentrations of RK28 in the tumor. As to metabolites of RK28, beta-glucuronated compound and cysteine conjugate were highly detected. The concentrations of cysteine conjugate were higher in the tumor than in serum via i.v. injection. CONCLUSIONS: Radiosensitizing effects of RK28 were observed on the rabbit VX-2 tumor system after i.a. or i.t. injection. Pharmacokinetic studies proved that radiosensitizing effects depended on the concentration in the tumor, though the administration routes were different. Combined forms with nonprotein thiols were detected. However, survival benefits were not obtained by RK28. For clinical applications of RK28, i.a. or i.t. injection could facilitate better local control of cancer.