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Biomedical subjects

A H Robbins

Publications and source records attributed to A H Robbins.

At least 37 records · Page 2Linked to original sources
PubMed1987

Early diagnosis of pancreatic infection by computed tomography-guided aspiration.

We performed 92 computed tomography-guided percutaneous needle aspirations of pancreatic inflammatory masses in 60 patients suspected of harboring pancreatic infection. Thirty-six patients (60%) were found by Gram stain and culture to have a total of 41 separate episodes of pancreatic infection. Among 42 aspirates judged to be infected by computed tomography-guided aspiration, all but one were confirmed by surgery or indwelling catheter drainage. Among 50 aspirates judged to be sterile, no subsequent evidence of infection was found. All patients tolerated the procedure well and no complications were noted. As a result of this technique, we observed that pancreatic infection occurs earlier than has been previously appreciated (within 14 days of the onset of pancreatitis in 20 of the 36 patients) and that infection may recur during prolonged bouts of pancreatitis. We conclude that guided aspiration is a safe, accurate method for identifying infection of the pancreas at an early stage.

Acute Disease↗
PubMed1987

Speech-controlled generation of radiology reports.

Voice entry has been successfully employed to generate radiology reports with a word recognizer with a 1,000-word lexicon capacity. About 50% of reports were able to be dictated with a single 900-word lexicon. This was split into five sections by anatomic or subspecialty application. Each was augmented to 900 words. By switching from one lexicon to another, it was possible to dictate more than 70% of reports. With exclusive use of three lexicons in subspecialty areas (gastrointestinal radiology, neuroradiology, and mammography), and with further modification of the respective vocabulary, it has been possible to employ the system 88% of the time. Twelve percent of cases included wording that was beyond the scope of the lexicon. Computer subsets that allow different translations of some words when used in different contexts have been used. Some of these are used as triggers that will print whole lines, sentences, or even complete reports. Dictation times with voice entry take about 20% longer. Recognition reliability has been greater than 95%.

Computers↗
PubMed1986

Crystal structure of Cd,Zn metallothionein.

The anomalous scattering data from five Cd in the native protein were used to determine the crystal structure of cadmium, zinc (Cd,Zn) metallothionein isoform II from rat liver. The structure of a 4-Cd cluster was solved by direct methods. A 2.3 A resolution electron density map was calculated by iterative single-wavelength anomalous scattering. The structure is folded into two domains. The amino terminal domain (beta) of residues 1 to 29 enfolds a three-metal cluster of one Cd and two Zn atoms coordinated by six terminal cysteine thiolate ligands and three bridging cysteine thiolates. The carboxyl terminal domain (alpha) of residues 30 to 61 enfolds a 4-Cd cluster coordinated by six terminal and five bridging cysteine thiolates. All seven metal sites have tetrahedral coordination geometry. The domains are roughly spherical, and the diameter is 15 to 20 A; there is limited contact between domains. The folding of alpha and beta is topologically similar but with opposite chirality. Redundant, short cysteine-containing sequences have similar roles in cluster formation in both alpha and beta.

Animals↗
PubMed1986

Endotoxin and tumor necrosis factor induce interleukin-1 gene expression in adult human vascular endothelial cells.

Interleukin 1 (IL-1) can induce potentially pathogenic functions of vascular endothelial cells. This mediator was formerly thought to be produced primarily by activated macrophages. We report here that bacterial endotoxin and recombinant human tumor necrosis factor cause accumulation of IL-1 beta mRNA in adult human vascular endothelial cells. IL-1 alpha mRNA was also detected when endothelial cells were exposed to endotoxin under "superinduction" conditions in the presence of cycloheximide. Metabolic labeling of these cells during endotoxin stimulation demonstrated increased synthesis and secretion of immunoprecipitable IL-1 protein that comigrated electrophoretically with the predominant monocyte species. In parallel with increased IL-1 mRNA and protein, endothelial cells exposed to endotoxin also release biologically active IL-1 that was neutralized by anti-IL-1-antibody. Because bloodborne agents must traverse the endothelium before entering tissues, endothelial IL-1 production induced by microbial products or other injurious stimuli could initiate local responses to invasion. Endothelial cells are both a source of and target for IL-1; accordingly, this novel autocrine mechanism might play an early role in the pathogenesis of vasculitis, allograft rejection, and arteriosclerosis.

Adult↗
PubMed1985

Iron-sulfur cluster in aconitase. Crystallographic evidence for a three-iron center.

Native x-ray diffraction data from single crystals of inactive aconitase from pig heart (Mr 80,000) have been collected on oscillation films to 2.7 A. Analysis shows that significant measurements of the anomalous scattering signal from the Fe-S cluster in the enzyme are available in the film data. The 5.0-A resolution anomalous difference Patterson function contains vectors for one Fe-S cluster (one aconitase molecule) per asymmetric unit in space group P2(1)2(1)2 with a = 173.6, b = 72.0, and c = 72.7 A. At 2.7-A resolution, the vector map is best interpreted by three Fe sites separated from each other by less than 3 A. The single-crystal diffraction data thus confirm the presence of a 3Fe center in the inactive form of aconitase. Furthermore, the data provide crystallographic evidence that 3Fe clusters exhibit structural heterogeneity. The Fe-Fe vectors cannot be interpreted in terms of 4-A distances as observed for the [3Fe-3S] cluster in Azotobacter ferrodoxin (Ghosh, D., O'Donnell, S., Furey, W., Robbins, A. H., and Stout, C. D. (1982) J. Mol. Biol. 158, 73-109). The results are therefore in agreement with a [3Fe-4S] cluster having 2.7-A Fe-Fe distances (Beinert, H., Emptage, M. H., Dreyer, J.-L., Scott, R. A., Hahn, J. E., Hodgson, K. O., and Thomson, A. J. (1983) Proc. Natl. Acad. Sci. U. S. A. 80, 393-396). However, the data do not unambiguously discriminate between this model and other 3Fe clusters having short Fe-Fe distances.

Aconitate Hydratase↗
PubMed1985

Expanded criteria for percutaneous abscess drainage.

The original criteria for percutaneous abscess drainage were limited to simple abscesses (well-defined, unilocular) with safe drainage routes. We expanded these entry criteria to include complex abscesses (loculated, ill-defined, or extensively dissecting abscesses), multiple abscesses, abscesses with enteric fistulas or whose drainage routes traversed normal organs, as well as complicated abscesses (appendiceal, splenic, interloop, and pelvic). Using these expanded criteria, cure was achieved nonoperatively in 92 (73.6%) of 125 abscesses with ten deaths (9%), and 11 complications (9%). Cure was achieved in 82% of simple abscesses, but only 45% of complex abscesses. There was no correlation between size, depth, drainage route, or etiology of the abscess (spontaneous v postoperative) with either cure or complications. We recommend a trial of percutaneous drainage in all simple abscesses and most complex abscesses with clinical response as the key determinant of the need for operative intervention.

Abscess↗
PubMed1985

Comparison of body composition in middle-aged and elderly males using computed tomography.

Computed tomography (CT) scans were taken of 21 middle-aged men (mean age 46.3 years) and 20 older men (mean age 69.4 years) to measure differences in body composition with age. Overall, the older men weighed 8.2 kg less than the middle-aged men, and this difference was primarily the result of their having less lean tissue. Although fat mass (by whole body potassium counting) was only slightly less in older men, there were distributional differences in fat between the age groups. Total abdomen adipose tissue area (from CT) was similar in both groups, although the subcutaneous portion of the abdomen adipose tissue was less in the older men, and they had correspondingly more adipose tissue within the abdominal cavity. Muscle areas of the leg and arm were significantly less in the older men, as were all lean tissues of the abdomen and chest. When these data were corrected for differences in body weight with age, the results were still significant, suggesting a centripetalization and internalization of fat with age. Causes of this apparent fat redistribution and decrease of lean tissue with age were not revealed by this study and are presently unknown.

Adipose Tissue↗
PubMed1985

Intrahepatic pyogenic abscesses: treatment by percutaneous drainage.

During a 6 year period, 18 liver abscesses in 12 patients were identified by computerized tomography. Five patients had presumed hematogenous seeding. Five patients previously had bilioenteric anastomoses, stents, or both to relieve obstructive jaundice. Four patients with abscesses had recent abdominal operations. Diagnosis was established by guided needle aspiration and treatment was provided by percutaneous catheter drainage. Organism-specific antibiotics were administered to all patients. Patients were evaluated for recurrence by serial computerized tomographic studies and were clinically followed up for a minimum of 15 months. Ten of 12 patients (83 percent) and 16 of 18 abscesses (89 percent) were successfully treated by percutaneous catheter drainage. Two failures required operative intervention. In summary, the low morbidity and high success rate in treating hepatic abscesses by percutaneous drainage suggests that this therapy be tried before operative intervention is considered.

Adult↗
PubMed1985

Complications of arthrography.

Arthrography is considered extremely safe since reactions to intraarticular contrast media are rare. We have only seen one severe complication in the performance of more than 2,000 arthrographic procedures. To determine the incidence of complications, a questionnaire was sent to 84 radiologists experienced in arthrography. The 57 respondents had performed more than 126,000 arthrographic procedures, and findings of the survey indicate no deaths, three cases of infection, and 61 cases of hives. Other acute reactions included hypotension, seizures, air embolism, and laryngeal edema. Related complications included sterile chemical synovitis, severe pain after the procedure, and vasovagal reactions.

Arthrography↗
PubMed1984

Percutaneous drainage of infected pancreatic pseudocysts.

After diagnostic needle aspiration guided by computed tomography and/or ultrasound, 11 infected pseudocysts in ten patients were treated nonoperatively by percutaneous catheter drainage and intravenously administered antibiotics. Nine infected pseudocysts resolved after 11 to 37 days (mean, 21 days) with no recurrences at follow-up 16 to 42 months (mean, 24.4 months) later. All were confirmed by Gram's stain, culture, and elevated amylase levels. Ten of the pseudocysts were acute; one was chronic; five were polymicrobial; six had a single organism. There were no major complications. There was one failure when a pancreatic abscess developed in a patient who died following operative drainage. There was one successful palliation of a postoperative-infected pseudocyst in a patient with an obstructing nonresectable carcinoma of the head of the pancreas. A trial of percutaneous catheter drainage is indicated in patients with infected pancreatic pseudocysts.

Adult↗
PubMed1984

The reticular pattern as a radiographic sign of the Barrett esophagus: an assessment.

A two-part retrospective study was conducted to assess the value of a reticular pattern as a sign of columnar-lined esophagus. Radiographic, endoscopic, and histologic findings were reviewed in 124 patients with known Barrett esophagus; then all barium esophagrams done at our institution during a 3 1/2 month period were reviewed and presence of a reticular pattern was correlated with available endoscopic and histologic data. In patients with known Barrett esophagus, the reticular pattern was found in 26% of double-contrast examinations. Twelve of these patients underwent careful esophageal mapping biopsies: the pattern was in squamous mucosa with ulceration in two, in columnar epithelium with ulceration in six, and in columnar epithelium without ulceration in four. In the group of 314 unselected patients who had double-contrast examinations, the reticular pattern was found in 26 (8%). Thirteen of the 26 had had endoscopy and biopsy: the site of the pattern was located in a squamous carcinoma in one, in squamous epithelium adjacent to squamous carcinoma in three, in squamous epithelium with esophagitis in five (two of whom had columnar mucosa distally), in normal squamous mucosa in one, and in columnar epithelium with esophagitis in three. The reticular pattern is a strong indicator of important esophageal disease, but is not specific for Barrett esophagus.

Barrett Esophagus↗
PubMed1984

Renal toxicity of contrast agents: iopamidol, iothalamate, and diatrizoate.

As part of a general safety study of iopamidol, a nonionic iodinated contrast agent, urine N-acetyl-beta-glucosaminidase enzyme assays were done to compare the renal toxicity of iopamidol with that of iothalamate and diatrizoate. In a randomized study of 30 patients for computed body tomography and another 30 patients for angiography, 10 in each group were injected with iopamidol, 10 with iothalamate, and 10 with diatrizoate. After computed tomography or angiography with the three agents, there was no significant difference in urinary enzyme levels among the groups. The nephrotoxicity of iopamidol appears equivalent to that of diatrizoate and iothalamate.

Acetylglucosaminidase↗
PubMed1984

Collateral pathways of the left gastric vein in portal hypertension.

Since June 1974, 347 percutaneous transhepatic portal venographic studies were performed on 246 patients with portal hypertension who had had bleeding gastroesophageal varices. Of 234 patients in whom left gastric veins (LGV) (coronary) were demonstrated, 177 (75.6%) had a single LGV and 57 (24.4%) had multiple left gastric veins (21.8% had two LGVs, 2.1% had three LGVs, and 0.5% had five LGVs). Of 193 patients undergoing selective left gastric venography, spontaneous portosystemic communications to the left renal vein were found in 55, to the inferior vena cava in two, to the inferior pulmonary veins in five, to the pericardiophrenic vein in eight, to the right inferior phrenic vein in three, and to the left intercostal veins in one. Interportal communications with the left gastric vein and varices occurred from the left portal vein in 13, from the gastroepiploic vein in one, and from a superior mesenteric vein branch in one. The predominant drainage of esophageal varices was to the azygos vein in 78 of 155 patients, to the hemiazygos vein in 13, and to multiple small unnamed veins in the mediastinum in 57. Opacified varices did not extend above the level of the azygos vein arch in 71 of 130 patients; however, 59 continued cephalad to the azygos arch and drained through more superior veins of the thorax. Knowledge of the anatomy and incidence of each of these portosystemic or interportal venous communications is important to properly treat bleeding esophageal varices by surgery or angiographic embolization.

Collateral Circulation↗
PubMed1984

Evaluation of Blom-Singer voice prosthesis.

Tracheoesophageal puncture and use of a silicone prosthesis is becoming a common and highly effective procedure for voice rehabilitation in the alaryngeal patient. Radiologic evaluations were reviewed of 31 patients scheduled for tracheoesophageal puncture at this institution over the past 3 years. Barium swallow examinations were performed preoperatively to assess anatomy and muscular activity of the pharyngoesophagus. Examinations were performed postoperatively when complications were suspected, phonation was unsatisfactory, or as routine oncologic follow-up. Postoperative complications included neck abscess, cervical osteomyelitis, and feeding tube dissection into the anterior wall of the thoracic esophagus. This method of pre- and postoperative radiologic evaluation of these patients is presented, along with the radiologic manifestations of the complications.

Aged↗
PubMed1984

Adenocarcinoma and Barrett's esophagus. An overrated risk?

The risk of developing esophageal cancer in Barrett's esophagus has been estimated at about 10%. This estimate is based primarily on data concerning the prevalence of that association in series of hospitalized patients and autopsies--a practice that tends to exaggerate the risk. We have reviewed retrospectively our experience with 115 patients whom we treated for Barrett's esophagus between September 1962 and March 1983, and have distinguished our data on the prevalence of esophageal cancer from that on incidence. For 8 patients, we found both Barrett's esophagus and esophageal adenocarcinoma during the initial evaluations for a prevalence ratio of 7%. We followed 105 patients not found to have esophageal cancer initially for a total of 350 person-years. Only 2 patients developed adenocarcinoma during that follow-up period for an incidence of 1 case per 175 person-years. This incidence, although some 40-fold greater than that of the general population, is substantially lower than previously estimated. Routine endoscopic and histologic surveillance has been recommended for patients with Barrett's esophagus because of the alleged high incidence of esophageal cancer. Inasmuch as that incidence now appears to be low, we question the value of such surveillance for these patients.

Adenocarcinoma↗
PubMed1983

Prevalence of normal serum amylase levels in patients with acute alcoholic pancreatitis.

Acute alcoholic pancreatitis is uncommonly diagnosed when the serum amylase level is normal. We defined acute alcoholic pancreatitis as a clinical syndrome in which hyperamylasemia was not a necessary component and sought support for the diagnosis by ultrasonography and computed tomography of the pancreas. In 68 episodes of acute alcoholic pancreatitis identified in a one-year period, the serum amylase level was normal at the time of hospital admission in 32%. In 40 episodes, we performed ultrasonography and computed tomography within 48 hr of admission. The diagnosis was supported by ultrasonography in 43%, by computed tomography in 68%. Ultrasonography and computed tomography supported the diagnosis as frequently in patients with normal serum amylase levels as in patients with hyperamylasemia. We conclude that patients with acute alcoholic pancreatitis frequently have normal serum amylase levels. The widespread clinical practice of relying solely on hyperamylasemia to establish the diagnosis of acute alcoholic pancreatitis is unjustified and should be abandoned.

Acute Disease↗