A performance bound on dynamic channel allocation in cellularsystems: equal load

We model a cellular network as a more general multiple service, multiple resource system. We define the “state” of the system as the number of calls currently carried in each cell. We restrict ourselves to channel allocation policies that place restrictions on the global state of the system, are allowed immediate global channel reallocation, and ignore handoffs. Maximum packing and fixed allocation are considered as special cases of such policies. Under uniform load conditions, we prove that throughput is increasing and concave with respect to increases in load or capacity, under maximum packing or fixed allocation. We propose that the optimal policy, in the considered class, varies from maximum packing at low loads to fixed allocation at high loads. This policy is often impractical to implement, but can be considered as a performance bound on practical systems. The analytical results are investigated numerically using a simple seven cell linear network     

Single agent activity of rhizoxin in non-small-cell lung cancer: a phase II trial of the EORTC Early Clinical Trials Group

In a multicentre trial of the EORTC-Early Clinical Trials Group (ECTG) we treated 31 chemotherapy-naive patients with advanced non-small-cell lung cancer (NSCLC) with rhizoxin, a novel tubulin-binding agent. The drug was given as an i.v. bolus injection at 2 mg m-2 once every 3 weeks in an outpatient setting. Prophylactic antiemetics were not routinely given. Of the 29 eligible patients, nine had been treated surgically and three had received radiotherapy. The main toxic effects observed were stomatitis (34% of cycles) and neutropenia (41% of cycles). Neutropenic fever was rare (3% of cycles). Twenty-seven patients were evaluable for response. There were four partial responses (15%), while 13 patients (48%) showed stabilisation of their disease. The median duration of response was 7 months (range 6.0-10.7 months) and median survival from the start of rhizoxin treatment was 6 months (range 2-14.7 months). Rhizoxin as single agent shows activity in patients with advanced NSCLC.     

Volumetric changes following barrier regeneration procedures for the surgical management of grade II molar furcation defects in baboons: II. Bone, cementum, epithelium, and connective tissue

Written guidelines based on current research on infant pain assessment and management were developed by an interdisciplinary team in a neonatal intensive care unit of a regional medical center. Charts for infants who had undergone abdominal surgery were reviewed to compare patient outcomes before and after use of this pain management protocol. With the standardization of pain management strategies, the following improvements were noted: decreased length of time to extubation, decreased length of stay, better fluid management, and reduced side effects of narcotics. Additional benefits included improved pain management documentation, decreased cost, and decreased nursing time.     

Fine needle aspiration cytology of oral and pharyngeal lesions. A study of 45 cases

Forty-five patients with oral or pharyngeal swellings were subjected to fine needle aspiration cytology (FNAC) of the mucosal surface over eight years. The age of the patients ranged from 2 to 85 years. The male:female ratio was 25:20. The common sites of involvement were palate (16 cases), cheek (9), pharynx (7) and tonsillar/peritonsillar area (6). Tongue, maxilla, alveolus and lips were less frequently involved. FNAC played an important role in differentiating inflammatory from neoplastic lesions and also benign from malignant neoplasms. Fifteen cases were cytologically diagnosed as benign neoplasms and included pleomorphic adenoma (11 cases), schwannoma (2), odontogenic tumor (1) and benign neoplasm not otherwise specified (1). Sixteen cases were diagnosed as malignancies. There were seven cases of malignant salivary gland tumors and 6 of squamous cell carcinoma. Two cases were high grade non-Hodgkin's lymphomas, and one was malignant odontogenic tumor. Of the 11 inflammatory or reactive lesions, 4 were found to be harboring Actinomyces. The rate of inadequate sampling was 6.7%. Histopathology reports on excised tissue were available for 10 cases only. Seven of nine cases with adequate cytology (77.88%) showed complete agreement with histology.     

U1-mediated exon definition interactions between AT-AC and GT-AG introns

A minor class of metazoan introns has well-conserved splice sites with 5'-AU-AC-3' boundaries, compared to the 5'-GU-AG-3' boundaries and degenerate splice sites of conventional introns. Splicing of the AT-AC intron 2 of a sodium channel (SCN4A) precursor messenger RNA in vitro did not require inhibition of conventional splicing and required adenosine triphosphate, magnesium, and U12 small nuclear RNA (snRNA). When exon 3 was followed by the 5' splice site from the downstream conventional intron, splicing of intron 2 was greatly stimulated. This effect was U1 snRNA-dependent, unlike the basal AT-AC splicing reaction. Therefore, U1-mediated exon definition interactions can coordinate the activities of major and minor spliceosomes.     

Histopathology of the liver in children with chronic hepatitis C viral infection

Although the epidemiology, natural history, and pathological aspects of chronic hepatitis C are well-defined in the adult population, little is known about the characteristics of chronic hepatitis C infection in children. Reports on the histological features and progression of hepatitis C in children are scarce, and consist primarily of multicenter studies in Japanese and European children. Given the geographic variations in viral genotype and the association of pathology with genotype, whether the Japanese and European studies can be extended to the North American populations is unclear. We report the histopathology of the liver in 40 children with chronic hepatitis C infection treated in a single North American institution. The children included 19 males and 21 females ranging in age from 2.0 to 18.6 years at the time of liver biopsy (mean +/- SD: 11.4 +/- 4.3 years). Our findings indicate that the characteristic histopathological lesions of chronic hepatitis C infection, including sinusoidal lymphocytosis, steatosis, portal lymphoid aggregates/follicles, and bile duct epithelial damage, occur with approximately the same frequencies in children as have been reported in adults. Necroinflammatory activity was generally mild. Portal fibrosis was present in 78% of the specimens, including fibrous portal expansion (26%), bridging fibrosis (22%), bridging fibrosis with architectural distortion (22%), and cirrhosis (8%). Centrilobular pericellular fibrosis, which has not been previously reported in the context of chronic hepatitis C infection in adults or children, was also a prominent feature in our series, occurring with a similar frequency as steatosis or portal lymphoid aggregates/follicles. Our data suggest that in spite of mild histological necroinflammatory activity in general, the stage of fibrosis in children can be severe in spite of relatively short duration of infection.     

Results of a policy of primary repair of truncus arteriosus in the neonate

Although the early mortality for repair of truncus arteriosus has decreased in the modern era, routine correction in the neonate has not been widely adopted. To assess the results of our protocol of early repair, we reviewed 46 neonates and infants undergoing repair of truncus arteriosus at the University of Michigan Medical Center from January 1986 to January 1992. Their ages ranged from 1 day to 7 months (median 13 days) and weights from 1.8 kg to 5.4 kg (mean 3.1 kg). Repair was performed beyond the first month of life in only 8 patients, because of late referral in 7 and severe noncardiac problems in 1. Associated cardiac anomalies were frequently encountered, the most common being interrupted aortic arch (n = 5), nonconfluent pulmonary arteries (n = 4), hypoplastic pulmonary arteries (n = 4), and major coronary artery anomalies (n = 3). Truncal valve replacement was performed in 5 patients with severe regurgitation, 3 of whom also had truncal valve systolic pressure gradients of 30 mm Hg or more. The truncal valve was replaced with a mechanical prosthesis in 2 patients and with a cryopreserved homograft in 3 patients. Right ventricle-pulmonary artery continuity was established with a homograft in 41 patients (range 8 mm to 15 mm), a valved heterograft conduit in 4 (range 12 mm to 14 mm), and a nonvalved polytetrafluoroethylene tube in the remaining patient (8 mm). There were 5 hospital deaths (11%, 70% confidence limits 7% to 17%). Multivariate and univariate analyses failed to demonstrate a relationship between hospital mortality and age, weight, or associated cardiac anomalies. Only 1 death occurred among 9 patients with interrupted aortic arch or nonconfluent pulmonary arteries. Hospital survivors were followed-up from 3 months to 6.3 years (mean 3 +/- 0.4 years). Late noncardiac deaths occurred in 3 patients, all within 4 months after the operation. Actuarial survival was 81% +/- 6% at 90 days and beyond. Despite the prevalence of major associated conditions, early repair has resulted in excellent survival. We continue to recommend repair promptly after presentation, optimally within the first month of life.