Search PubMed⌕ Search

Biomedical subjects

J Coleman

Publications and source records attributed to J Coleman.

At least 127 records · Page 7Linked to original sources
PubMed1990

Current management of the Budd-Chiari syndrome.

Twenty-six patients with the Budd-Chiari syndrome were treated surgically at the Johns Hopkins Hospital. Twenty-one of the patients were female and five were male, with a median age at diagnosis of 37 years. Nine patients had polycythemia vera, 6 were receiving estrogen therapy, 5 had a previous hepatitis A or B infection, and 4 had cirrhosis. There was one case each of hepatic malignancy, paroxysmal nocturnal hemoglobinuria, and idiopathic thrombocytopenic purpura. In five cases no etiologic factors or associated disorders were identified. Ascites was the most common presenting feature in this group of patients. Hepatic function at the time of diagnosis, as measured by standard serum chemistries, was only minimally abnormal. The diagnosis of the Budd-Chiari syndrome was confirmed in all 26 patients by hepatic vein catheterization. Inferior vena cavography was also performed and revealed caval occlusion in 4 patients, significant caval obstruction in 13 patients, and a normal vena cava in 9 patients. Interpretation of the vena cavogram was helpful in selecting the appropriate surgical procedure for each patient. Twenty-three of the twenty-six patients underwent percutaneous liver biopsy before operation, with no morbidity or mortality. Four patients had well-established cirrhosis noted on biopsy. Thirty mesenteric-systemic venous shunts were performed on the 26 patients. In 11 patients a mesocaval shunt was performed and in one instance conversion to a mesoatrial shunt was required as a second procedure. In 15 patients a mesoatrial shunt was performed as the initial procedure. Graft thrombosis occurring in 2 of these 15 patients prompted one revision in 1 patient and 2 revisions in the second patient. After mesenteric-systemic venous shunt, eight of the patients (31%) died before discharge from the hospital. The remaining 18 patients in this series were discharged from the hospital alive and well with patent shunts. Patients were followed for a median of 43 months (range, 9 months to 13 years). Five late deaths occurred between 5 and 84 months after the operation. Three- and five-year actuarial survival rates were 65% and 59%, respectively.

Adolescent↗
PubMed1990

Broad spectrum penicillin as an adequate therapy for acute cholangitis.

In a previous study of patients with acute cholecystitis, we demonstrated equal efficacy with a broad spectrum penicillin (piperacillin) and a penicillin plus amino-glycoside combination. Whether a single agent broad spectrum penicillin is adequate treatment for more severe infections, such as acute cholangitis, however, is still unclear. We, therefore, conducted a three center, prospective, randomized trial to determine whether or not a broad spectrum penicillin alone is adequate therapy for patients with acute cholangitis. During a 36 month period, 96 patients with sepsis and biliary obstruction were randomly assigned to receive either piperacillin (n = 49) or ampicillin plus tobramycin (n = 47). The two groups receiving antibiotics were similar with respect to all clinical and laboratory parameters. The incidence of blood cultures with positive results (20 versus 21 per cent) and underlying malignant lesions (51 versus 62 per cent) was also similar between the two groups. The percentage of patients with a clinical cure or significant improvement was the same in the two groups (69 versus 70 per cent). However, there was a significant difference in the cure rate between patients with benign and malignant biliary obstructions (83 versus 59 per cent, p less than 0.01). No significant differences were noted between the two antibiotic groups with respect to drug toxicity, but patients with malignant conditions were more prone to antibiotic related toxicities (2 versus 19 per cent, p less than 0.05). These data suggest that outcome of treatment in patients with acute cholangitis is similar with either a broad spectrum penicillin or a penicillin plus aminoglycoside combination and is dependent upon the nature of the biliary obstruction.

Acute Disease↗
PubMed1989

Benign postoperative biliary strictures. Operate or dilate?

At The Johns Hopkins Hospital from 1979 through 1987, 42 patients had 45 procedures for benign postoperative biliary strictures. Three patients were managed with both surgery and balloon dilatation. Twenty-five patients underwent surgical repair with Roux-Y choledocho- or hepaticojejunostomy with postoperative transhepatic stenting for a mean of 13.8 +/- 1.3 months. Twenty patients had balloon dilatation a mean of 3.9 times and were stented transhepatically for a mean of 13.3 +/- 2.0 months. The two groups were similar with respect to multiple parameters that might have influenced outcome. Mean length of follow-up was 57 +/- 7 and 59 +/- 6 months for surgery and balloon dilatation, respectively. No patients died after any of the procedures. The same definition of a successful outcome was applied to both groups and was achieved in 88% of the surgical and in only 55% of the balloon dilatation patients (p less than 0.02). Significant hemobilia occurred more often with balloon dilatation (20% vs. 4%, p less than 0.02). The total hospital stay and cost of balloon dilatation was not significantly different from surgery. We conclude that surgical repair of benign postoperative strictures results in fewer problems that require further therapy. Nevertheless balloon dilatation is an alternative for patients who are at high risk or who are unwilling to undergo another operation.

Catheterization↗
PubMed1988

Resection of hepatic duct bifurcation and transhepatic stenting for sclerosing cholangitis.

Thirty-one patients with sclerosing cholangitis underwent reconstruction of their hepatic duct bifurcation and long-term stenting between 1980 and 1987. Indications for surgery were persistent jaundice in 29 and recurrent cholangitis in two. The mean serum bilirubin level before surgery was 10.4 mg/dl. Liver biopsy revealed that 26 patients had varying degrees of hepatic fibrosis, and five patients had progressed to secondary biliary cirrhosis. In 29 patients the major obstructive duct disease was at or near the hepatic duct bifurcation, and in two patients it was in the distal common duct. The operative procedure consisted of: (1) excision of the hepatic duct bifurcation and extrahepatic biliary tree, (2) dilatation of the intrahepatic ducts, (3) insertion of Silastic transhepatic biliary stents, and (4) bilateral hepaticojejunostomies. Two of the five patients (40%) with cirrhosis died after surgery. In contrast, only one of 26 patients (3.9%) with hepatic fibrosis died after operation. The 1-, 3-, and 5-year actuarial survival rates for patients with cirrhosis were 20%, 20%, and 20%, respectively. The only long-term survivor underwent a liver transplant. The 1-, 3-, and 5-year actuarial survival rates for patients with hepatic fibrosis were 92%, 87%, and 71%, respectively. In addition, the mean serum bilirubin levels of patients with hepatic fibrosis at 1, 2, 3, 4, and 5 years were 3.4 mg/dl, 2.9 mg/dl, 4.0 mg/dl, 5.4 mg/dl, and 4.3 mg/dl, respectively. Two of the long-term survivors subsequently underwent a liver transplant. Patients with sclerosing cholangitis, persistent jaundice, and biliary cirrhosis should be referred for consideration of liver transplantation. However, in the absence of biliary cirrhosis, if the major obstructive disease is at the hepatic duct bifurcation, primary biliary reconstruction and long-term stenting should be considered.

Adult↗
PubMed1988

Identity of the 17-kilodalton protein, a DNA-binding protein from Escherichia coli, and the firA gene product.

The 17-kilodalton protein, a DNA-binding protein encoded by the skp gene of Escherichia coli, was found to be identical to histonelike protein I, the product of the firA gene. This conclusion was reached after chromosomal localization, using the recently constructed high- and low-resolution E. coli restriction maps, and by direct comparison of the N-terminal amino acid sequence of histonelike protein I and the 17-kilodalton protein.

Chromosome Mapping↗
PubMed1988

First committed step of lipid A biosynthesis in Escherichia coli: sequence of the lpxA gene.

The min 4 region of the Escherichia coli genome contains genes (lpxA and lpxB) that encode proteins involved in lipid A biosynthesis. We have determined the sequence of 1,350 base pairs of DNA upstream of the lpxB gene. This fragment of DNA contains the complete coding sequence for the 28.0-kilodalton lpxA gene product and an upstream open reading frame capable of encoding a 17-kilodalton protein (ORF17). In addition there appears to be an additional open reading frame (ORF?) immediately upstream of ORF17. The initiation codon for lpxA is a GUG codon, and the start codon for ORF17 is apparently a UUG codon. The start and stop codons overlap between ORF? and ORF17, ORF17 and lpxA, and lpxA and lpxB. This overlap is suggestive of translational coupling and argues that the genes are cotranscribed. Crowell et al. (D.N. Crowell, W.S. Reznikoff, and C.R.H. Raetz, J. Bacteriol. 169:5727-5734, 1987) and Tomasiewicz and McHenry (H.G. Tomasiewicz and C.S. McHenry, J. Bacteriol. 169:5735-5744, 1987) have demonstrated that there are three similarly overlapping coding regions downstream of lpxB including dnaE, suggesting the existence of a complex operon of at least seven genes: 5'-ORF?-ORF17-lpxA-lpxB-ORF23-dnaE-ORF37-3 '.

Acyltransferases↗
PubMed1988

Q fever following bone marrow transplantation.

We describe a patient who developed an acute febrile illness 85 days after receiving an allogeneic bone marrow transplant for acute myeloid leukaemia. Serological investigation indicated the cause to be Q fever. The patient was receiving concurrent immunosuppressive therapy for graft-versus-host disease (GVHD). Coxiella burnetii should be added to the list of organisms which may complicate bone marrow transplantation. This case also provides further evidence to support an association between immunocompromised conditions and the development of Q fever.

Adult↗
PubMed1987

Hepatitis B vaccine: immunogenicity and follow-up including two year booster doses in high-risk health care personnel in a London teaching hospital.

One hundred forty-four adult health care personnel (aged 18-62 years, median 33 years) considered at high risk of future HBV infection were vaccinated with a plasma-derived hepatitis B vaccine (20 micrograms HBVax at 0, 1, and 6 months) and followed-up for 2 years. Anti-HBs was present in only 6.9% prior to vaccination, and prescreening to detect this group would not have been cost-effective. At 9 months, 8.3% were nonresponders and a further 9% had anti-HBs levels less than 50 mIU/ml. Multivariate analysis showed that age was the single most important determinant of a poor response. In 47 of 52 individuals retested 2 years later, anti-HBs levels had fallen by 80% or more, and in four it had become undetectable. Response to a booster dose at this stage was excellent, with anti-HBs levels 3 months later much higher than at the end of the initial course. Additional booster doses of vaccine in two of the initial nonresponders at 14 and 22 months, respectively, also led to seroconversion. Although a significant proportion of health care workers in this study did not make a satisfactory response to the hepatitis B vaccine, later booster doses were very effective in subsequently increasing anti-HBs levels.

Adolescent↗
PubMed1987

Health and environmental effects profile for pentachloronitrobenzene.

Pure pentachloronitrobenzene (PCNB) is a colorless crystalline solid (Worthing, 1983). The commercial product may have a light-yellow to cream color with a musty odor (Hartley and Kidd, 1983). It is practically insoluble in a number of organic solvents. The compound is reasonably stable but may undergo hydrolysis in a strong alkaline medium (Hartley and Kidd, 1983). In 1983, Olin Corp., Leland, MS, was the only manufacturer of PCNB in the United States (SRI, 1984; Hartley and Kidd, 1983). No data for U.S. production volume for this chemical are available, but recent production source data (USITC, 1985; SRI, 1985) suggest that this chemical is no longer commercially produced in the United States. The primary usage of PCNB is as a soil fungicide for a wide variety of crops and in seed treatment (Worthing, 1983; Hartley and Kidd, 1983). The fate of PCNB in water has not been comprehensively studied. Only qualitative data regarding fate and transport in water are available. The half-life of PCNB in the water phase was estimated to be 1.8 days. The two processes reported to be most responsible for the rapid decrease in PCNB concentration in water were volatilization and sorption to seston and biota, followed by sedimentation as detritus (Schauerte et al., 1982). Neither biodegradation nor photolysis appears to be a significant process for the loss of PCNB from water (Crosby and Hamadmad, 1971; Schauerte et al., 1982). The BCFs for PCNB in the golden orfe, Leucisens idus melanotus, and in rainbow trout, Salmo gairdneri, were reported to be 950-1130 and 260-590, respectively (Korte et al., 1978; Oliver and Niimi, 1985). It therefore appears that PCNB will moderately bioaccumulate in aquatic organisms. Pertinent data regarding the fate and transport of PCNB in air could not be located in the available literature as cited in the Appendix. Based on its physical properties and its behavior in other media, it would appear that PCNB will persist in the atmosphere because no known chemical/photochemical processes significantly degrade this chemical. Precipitation of particulate PCNB, especially of larger particle size and higher particle density, may remove some PCNB from the atmosphere. PCNB is persistent in soils. The two processes that are important in the loss of PCNB from soils are volatilization and biodegradation; biodegradation is more rapid in soils under anaerobic conditions than under aerobic conditions (Ko and Farley, 1969; Casley, 1968; Gile and Gillett, 1979; Cole and Metcalf, 1977).(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1986

Pharmacokinetics and pharmacodynamics of pentopril, a new angiotensin-converting-enzyme inhibitor in humans.

In a single, ascending-dose tolerance study, nine healthy volunteers were given oral pentopril 50 to 750 mg (CGS 13945) in groups of three each. Disposition characteristics of pentopril and its active metabolite (CGS 13934) were determined using plasma concentration and urinary excretion data. The drug was absorbed rapidly following zero-order kinetics. The drug has an apparent volume of distribution of 0.83 L/kg and an oral clearance of about 0.79 L/hr/kg. Urinary excretions, calculated after 125- and 250-mg doses, showed a dose proportional urinary recovery of 21% (+/- 5%) for pentopril and 40% (+/- 5%) for CGS 13934. In the multiple-dose study of 125 mg orally q12h in six healthy subjects, the plasma concentrations for both drug and metabolite showed no appreciable accumulation of either compound, which was expected from their short pharmacokinetic half-lives (pentopril, less than 1 hr; CGS 13934, approximately 2 hr). In a separate pharmacodynamic study, drug and metabolite concentrations were evaluated against angiotensin-I (AI)-induced changes in blood pressure and plasma angiotensin-converting-enzyme (ACE) activity in healthy volunteers after single oral doses (range, 10-500 mg). The pharmacodynamic half-life for plasma ACE inhibition increased with the dose (10 mg, 1.5 hr; 500 mg, 9.8 hr). There was a close relationship between the plasma level of the metabolite and the inhibition of plasma ACE activity and AI-induced pressor response. A hyperbolic function adequately described the dependence of plasma ACE activity on plasma metabolite concentration with a concentration at half-maximal inhibition of 53 ng/mL.

Administration, Oral↗
PubMed1986

Immunological response to stress in agoraphobia and panic attacks.

The authors studied in vitro immune function as measured by lymphocytic proliferative response to mitogen stimulation in 36 patients with agoraphobia and panic attacks who were participating in a double-blind placebo-controlled psychopharmacological study of anxiety disorder. No significant difference in immune status was observed between panic patients and healthy controls.

Adult↗
PubMed1986

The Aberdeen Mark II single-photon-emission tomographic scanner: specification and some clinical applications.

The construction, operation and physical characteristics of a single-section multi-detector single-photon-emission scanner are described. The machine has 24 detectors arranged along the sides of a square. Movements and data collection are under the control of a series of distributed microprocessors. Both head and trunk tomograms can be produced. The spatial resolution at the collimator focus is 9 mm in the transverse plane, and the effective slice thickness is 14 mm. The volume sensitivity is 300 counts/s kBq ml with a 20 cm diameter cylindrical phantom filled with 99Tcm solution. The application of this machine to the examination of the brain, liver and heart has been found to be clinically useful.

Brain↗
PubMed1985

Mutations upstream of the ribosome-binding site affect translational efficiency.

The DNA coding for the major outer membrane lipoprotein of Escherichia coli has been fused to the coding region of the beta-galactosidase gene to measure the effect of various mutations on the efficiency of translation initiation. The various mutants were made by either inserting or deleting a small number of nucleotides into or from a region just upstream of the ribosome-binding site. These small mutations dramatically affect translation initiation as measured by the production of beta-galactosidase. We postulate that these mutations affect translation initiation by altering the secondary structure of the messenger RNA. In one case, we predict that a stem and loop just upstream of the Shine-Dalgarno sequence sterically hinders the binding of the ribosome to the mRNA.

Base Sequence↗
PubMed1985

Effect of food on the bioavailability of pentopril, an angiotensin-converting-enzyme inhibitor, in healthy subjects.

Pentopril (CGS 13945) was administered in 125-mg capsules to eight healthy men on two occasions according to a randomized schedule; on one occasion in the fasting state and on the other occasion immediately following the ingestion of a standardized meal. Unlike captopril, a prototype angiotensin-converting-enzyme inhibitor, there was no significant difference in the peak plasma concentration for either the drug or its active metabolite (CGS 13934) between the fasting and the fed states. There was also no appreciable change in the area under the plasma curve for the drug and its metabolite after administration of drug in the presence of food compared with a fasting state. There was, however, a lag time in drug absorption after ingestion of food, which resulted in a significant increase in peak time for the active metabolite in plasma. Food delays the body's absorption of the drug and hence the appearance of its active metabolite in plasma without any significant effect on the relative bioavailability. Because relative bioavailability is not affected in the presence of food, such a delay may not have any therapeutic importance on chronic administration.

Angiotensin-Converting Enzyme Inhibitors↗