Carcinoma of the body and tail of the pancreas.

Recently, several institutions have reported improved results in the treatment of patients with carcinoma of the head of the pancreas. In an attempt to determine whether similar trends could be demonstrated for patients with carcinoma of the body and tail of the pancreas, the records of all 113 patients with an adenocarcinoma of the body or tail of the pancreas treated at The Johns Hopkins Hospital between 1972 and 1989 were reviewed. The patients were divided into two groups: those diagnosed between 1972 and 1982 (41 patients) and those between 1983 and 1989 (72 patients). No significant differences in tumor stage were observed between the two groups. The proportion of patients who underwent surgery decreased from 68% to 47% (p = 0.02). The number of patients who had bypass operations (15% versus 17%) or pancreatic resection (5% versus 10%) was similar in the two groups, but the proportion of patients who underwent exploratory laparotomy with biopsy only decreased from 49% to 21% (p = 0.002). The postoperative 30-day mortality (7% versus 3%), postoperative morbidity (18% versus 21%), median survival (4 months versus 3 months), and the 1-year survival (8% versus 9%) did not differ significantly between the two groups. One patient survived for 6 years after resection, and another patient is still alive 3 years after resection. Thus, unlike adenocarcinoma of the head of the pancreas, it appears that treatment results for patients with adenocarcinoma of the body or tail of the pancreas have not improved in recent years, the only change being a decreased need for exploratory laparotomy with biopsy only.     

Sticking coefficients of adsorbing proteins.

The protein sticking coefficient, phi, the fraction of collisions that result in adsorption, is a function of the molecular interactions between the protein and the surface. A random walk and diffusion-to-capture model was used to describe the kinetics of protein adsorption. The assumption of a constant sticking coefficient leads to a first-order model of the kinetics. A solution of the problem of adsorption from a semi-infinite medium with first-order kinetics at the boundary was obtained by numerical simulation on the computer. The results of the computer simulations match the time dependence observed experimentally. A correlation was developed to estimate phi from experimental data. phi has been found to be in the range 10(-5)-10(-8) for several protein adsorption kinetic studies reported in the literature.     

EEG findings in hypomelanosis of Ito.

The EEG findings in 15 children with Hypomelanosis of Ito have been reviewed and related to the clinical and CT scan data. Although no consistent electroclinical associations were found in the group as a whole, there was some association between the presence of abnormal rhythmic EEG activity and the radiological appearances of neuronal migration defects. In addition, the possibility is raised that there may be a distinctive sub-group of children with Ito's syndrome who present with an early onset of intractable seizures and who have a neuronal migration defect.     

Albumin adsorption on alkyl chain derivatized polyurethanes. II. The effect of alkyl chain length

Linear alkyl chains containing 2, 10 and 18 carbon atoms were grafted to 10% of the urethane nitrogens in a polyether-polyurethane. The polyurethane was synthesized from methylene bis(p-phenyl isocyanate), 1,4-butanediol, and polytetramethylene oxide of 1000 molecular weight in a molar ratio of 3/2/1. Fourier transform infrared spectroscopy and attenuated total reflectance optics were used to study the adsorption of 5.0 mg/ml human serum albumin (HSA) at 37 degrees C to the derivatized and non-derivatized polymers. Both delipidized HSA and HSA containing 6.5 mol stearic acid per mol of albumin were used to study the effect of chain length upon the initial adsorption rate, the total amount adsorbed in 1 h, and the desorption rate. The initial adsorption rates revealed that non-specific adsorption was similar upon all four polymers. An increase in initial adsorption rate upon the C-18 derivatized polymer was attributed to a specific binding interaction between the HSA and the grafted alkyl chains. The conformational stability of the HSA also affected the adsorption rate. The total amount adsorbed after 1 h decreased as the alkyl chain length increased from 2 to 18 methylene groups. The desorption rate decreased in magnitude as the alkyl chain length increased from C-2 to C-18. These results support a hypothesis that alkyl chain length influences the interaction between albumin and an alkylated polymer system.     

Acute cholangitis

Cholangitis is an infection of the biliary ductal system that results from the combination of bactibilia and biliary obstruction. Choledocholithiasis has been the leading cause of cholangitis. However, in recent years, especially at tertiary referral centers, nonoperative biliary manipulations, often in patients with unresectable malignancies, have become the most common cause of cholangitis. As a result, the complete triad of fever and chills, jaundice, and abdominal pain, as originally described by Charcot, is now seen less frequently. Most patients still have leukocytosis and abnormal liver function tests, but many patients with indwelling tubes may develop cholangitis without significant jaundice. E. coli, Klebsiella species, and the enterococci remain the most frequently isolated organisms, and anaerobes including Bacteroides fragilis are recovered in 15% to 30% of patients. However, Enterobacter and Pseudomonas species, as well as yeasts, are now being isolated more frequently from patients with indwelling tubes, who often have been treated previously with antibiotics. Computed cholangiography usually is necessary to determine the cause and site of biliary obstruction. In the majority of patients with cholangitis, cholangiography can be delayed until the patient has been afebrile for a minimum of 24 to 48 hours. Initial therapy includes bowel rest, intravenous fluids, and antibiotics. Many antibiotic regimens are now available to cover the gram-negative aerobes, the enterococcus, and the anaerobes that are likely to be causing the biliary infection. The combination of a penicillin and an aminoglycoside has been the gold standard. However, recent studies suggest that the newer broad-spectrum penicillins provide adequate therapy for these patients. Only a small percentage (5%-10%) of patients with toxic cholangitis require emergency biliary decompression. The choice of percutaneous or endoscopic drainage should be made on the basis of the presumed site and cause of obstruction as well as local expertise. The nature of the biliary obstruction may be the most important determinant of outcome. At present, patients with end-stage malignant obstruction account for most of the deaths, whereas approximately 95% of patients survive an episode of cholangitis.     

Imaging of the pelvis and hip

Imaging is basic in the orthopedic evaluation of hip disorders. For optimal evaluation of these images, the orthopedic surgeon must not only correlate normal anatomy and pathology with radiographic findings, but must also be familiar with the newer modalities of CT, magnetic resonance imaging and ultrasound and the role and place of these studies in the evaluation of musculoskeletal disorders. This article correlates normal anatomy of the hip with these modalities and discusses the details of these techniques, particularly CT and MRI, that are pertinent to the orthopedic surgeon.     

Staphylococcus aureus isolates carrying Panton-Valentine leucocidin genes in England and Wales: frequency, characterization, and association with clinical disease

Staphylococcus aureus isolates carrying the genes that encode for Panton-Valentine leucocidin (PVL), a highly potent toxin, have been responsible for recent outbreaks of severe invasive disease in previously healthy children and adults in the United States of America and Europe. To determine the frequency of PVL-positive isolates sent to the Staphylococcus Reference Unit (United Kingdom) for epidemiological purposes, we tested 515 isolates of S. aureus, and 8 (1.6%) were positive for the PVL locus. A further 470 isolates were selected to explore the association of PVL-positive S. aureus with clinical disease. Of these, 23 (4.9%) were PVL positive and most were associated with skin and soft tissue infections (especially abscesses). The PVL genes were also detected in isolates responsible for community-acquired pneumonia, burn infections, bacteremia, and scalded skin syndrome. Genotyping by pulsed-field gel electrophoresis and multilocus sequence typing revealed that the PVL-positive isolates were from diverse genetic backgrounds, although one prevalent clone of 12 geographically dispersed methicillin-resistant S. aureus (MRSA) isolates was identified (ST80). All 12 isolates were stapylococcal cassette chromosome mec type IVc, had an agr3 allele, and shared a common toxin gene profile (sea-see, seg-sej, eta, etb, and tst negative but etd positive). ST80 strains with similar genetic characteristics have been responsible for community-acquired infections in France and Switzerland. The remaining PVL-positive isolates were mostly methicillin-sensitive S. aureus and belonged to 12 different sequence types, including ST22 and ST30, which are closely related to the most prevalent MRSA clones in United Kingdom hospitals, EMRSA-15 and EMRSA-16, respectively.