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Biomedical subjects

R R Black

Publications and source records attributed to R R Black.

At least 19 recordsLinked to original sources

Detection of acute osteomyelitis with indium-111 labeled white blood cells in a patient with sickle cell disease.

A young patient with sickle cell disease (SCD) and multiple hospitalizations for crisis was admitted because of suspected osteomyelitis. Initial laboratory work, radiographs, and bone images were not contributory. An In-111 white blood cell (WBC) study demonstrated two areas of increased radionuclide uptake consistent with osteomyelitis. One of these had associated soft tissue infection. No other areas of active osteomyelitis were visualized, in spite of the presence of several additional infection sites. Imaging with In-111 WBC is probably not justified for routine diagnosis of acute osteomyelitis in areas free of previous disease, where conventional bone images are highly efficient. In-111 WBC imaging, however, may be helpful in detecting osteomyelitis in selected patients with SCD in whom Tc-99m bone images and radiographs are usually abnormal and difficult to interpret due to previous bone infarcts. Localization of the infection focus is very important in choosing the aspiration site for bacteriologic studies. A negative study, however, should be interpreted cautiously.

Adolescent↗

Solitary defect on liver sulfur colloid imaging secondary to focal fatty infiltration.

Radionuclide liver-spleen imaging using Tc-99m SC may identify focal defects on routine examinations. Fatty infiltration has generally been described as a diffuse process in the liver that may be manifested on Tc-99m SC liver imaging as a nonhomogeneous pattern of radiopharmaceutical distribution or multiple small defects. This case demonstrates a focal defect on radionuclide imaging, simulating a space-occupying lesion that ultimately proved to be focal fatty infiltration. Although not an uncommon finding on CT, to the authors' knowledge this has not been reported in the nuclear medicine literature to date.

Adipose Tissue↗

Altered lectin binding by colonic epithelial glycoconjugates in ulcerative colitis and Crohn's disease.

Evidence is accumulating that colonic mucin glycoconjugates are altered in ulcerative colitis. In order to investigate this further, the lectin-binding properties of rectal glycoconjugates have been studied in ulcerative colitis, Crohn's disease, and controls using lectin-peroxidase histochemistry. Ten lectins were used including peanut agglutinin (PNA) which is known to bind to malignant and adenomatous but not normal colonic mucins. Eight of 21 ulcerative colitis rectal biopsies and 10 of 17 Crohn's disease rectal biopsies showed PNA positivity, particularly in the supranuclear region of surface epithelial cells. There was no correlation between PNA positivity and duration of disease or inflammation, and none of the biopsies showed evidence of dysplasia. This abnormality in epithelial cell glycoconjugates seems to be commonly present in nondysplastic mucosa and occurs in both ulcerative colitis and Crohn's disease. It may reflect a fundamental abnormality in mucus glycoprotein synthesis in inflammatory bowel disease.

Adult↗

Anatomic and position-induced increased radiopharmaceutical uptake in the cervical spine on bone imaging.

The finding of increased radiopharmaceutical (RP) in the cervical spine was noted in a patient when placed in the full forward flexion position. When imaged in the neutral position, this finding was not noted. A series of 10 consecutive patients demonstrated this finding. The positioning of the cervical spine erroneously manifested increased RP uptake, which may mimic disease and should be taken into account when positioning the cervical spine for routine imaging.

Adult↗

Incidental detection of obstructive uropathy during scrotal imaging.

The customary method for radionuclide imaging in patients with testicular pain is to image the scrotal region using Tc-99m pertechnetate. Acute obstructive uropathy was found to be the cause of the testicular pain in three adult patients with normal testicular perfusion using Tc-99m DTPA. Tc-99m DTPA is recommended for testicular imaging with concomitant imaging of the kidneys and ureters, particularly in the adult patient.

Adult↗

Intra-abdominal abscess demonstrating an unusually large intra-abdominal pattern on an indium-111 leukocyte scan.

Indium-111 WBC imaging of a patient with occult septicemia revealed a large focal pattern of radiopharmaceutical distribution within the abdominal cavity at 24 hours post radiopharmaceutical administration. This finding was felt to represent a large intra-abdominal abscess. A five liter peritoneal abscess was found at surgery. This case illustrates an unusual presentation of an intra-abdominal abscess.

Abdomen↗

Glycoprotein abnormalities in colonic carcinomata, adenomata, and hyperplastic polyps shown by lectin peroxidase histochemistry.

A technique for lectin-peroxidase histochemistry was adapted for the study of formalin fixed paraffin embedded colonic tissue. Ten lectins with differing carbohydrate binding specificity were tested against 20 normal rectal biopsy specimens and tissue from 19 colonic carcinomata, 19 tubular or tubulovillous adenomata, and 19 hyperplastic polyps. None of the normal rectal biopsy specimens bound the lectins peanut agglutinin (PNA), Griffonia simplicifolia II (GSII), and Ulex europaeus I (UEAI), whereas 18 carcinomata, 12 adenomata, and 18 hyperplastic polyps showed affinity for one or more of these lectins. Hyperplastic colonic polyps are shown to possess similar abnormalities in glycoprotein structure to malignant and adenomatous colonic tissue. This may simply indicate a non-specific reaction to changed rates of cell proliferation but might represent a more fundamental association between hyperplastic polyps and adenocarcinomas.

Adenoma↗

Histochemical demonstration of desialation and desulphation of normal and inflammatory bowel disease rectal mucus by faecal extracts.

Experiments were carried out to assess the susceptibility of normal and inflammatory bowel disease rectal mucus to desulphation and desialation by faecal extracts and by bacterial sialidase. The effects were assessed histochemically using a combined high iron diamine (HID) and alcian blue (AB) stain for sulphomucins and sialomucins. Rectal mucus in biopsies from controls (irritable bowel syndrome) and patients with ulcerative colitis or Crohn's disease was resistant to desialation by Clostridium perfringens sialidase, but susceptible to desialation and desulphation by bacteria-free extracts of normal faeces. Periodic acid-Schiff (PAS) staining of adjacent sections similarly treated showed retention of neutral mucus. One faecal extract selectively desulphated all 42 biopsies, causing the goblet cells to change from HID positive to AB positive, suggesting that most, or all HID positive cells also contain sialomucins. This alters the interpretation of previous histochemical studies. Faecal extracts from patients with active ulcerative colitis (n = 6) had desialating and desulphating effects similar to faecal extracts from normal subjects (n = 6). Ulcerative colitis (n = 21), Crohn's disease (n = 18), and control (irritable bowel syndrome) (n = 17) rectal biopsies all showed similar susceptibility to desulphation by a pooled normal faecal extract, but rectal biopsies from patients with Crohn's disease proved more resistant to desialation than control or ulcerative colitis biopsies (p less than 0.02). These studies imply that colonic mucus undergoes continual desulphation and desialation in vivo as a result of faecal enzyme activity that is probably mainly of bacterial origin. Altered susceptibility of colonic mucus to this may be important in the pathogenesis of colonic disease.

Adolescent↗

Practice locations of family practice residency graduates.

The purpose of this study was to examine the practice location patterns of 1970-1978 graduates of family practice residency programs. Comparisons were made between the number of graduates practicing in a region in 1979 with the number of all graduates during 1970-1978 from family practice residency programs in that region and with the number of all graduates from medical schools in that region who eventually completed family practice residencies elsewhere. The Middle Atlantic and West North Central regions showed marked decreases, while the Mountain, Pacific, and New England regions showed increases. The majority practiced more than 100 miles from their residency program. Most respondents practicing in a nonmetropolitan area moved outside of a 100-mile radius from their residencies. Most respondents practicing in a metropolitan area practiced within the 100-mile radius. Physicians were likely to be practicing in a community similar to their backgrounds.

Family Practice↗

Hospital privileges for family physicians: a national study of office based members of the American Academy of Family physicians.

In 1980 the American Academy of Family Physicians sampled those active members who were nonfederal, office based physicians in direct patient care to ascertain the characteristics of their hospital practices. The sample was stratified by the nine US census regions: 83.7 percent of the 5,216 active members in the sample responded. The vast majority of family physician/general practitioners in direct patient care in an office based setting have hospital admission privileges in one or more hospitals. A higher percentage of family physicians/general practitioners in census regions west of the Mississippi River were likely to have privileges in obstetrics and surgery than those in eastern regions. Moreover, family physicians/general practitioners in the nonmetropolitan areas of each census region were more likely to have hospital privileges at any level than were their colleagues in the metropolitan areas of the same region. Although there were disparities in the proportions of family physician/general practitioners with certain hospital privileges among regions, the vast majority in each region indicated that the privileges afforded them were appropriate.

Data Collection↗

Hospital privileges for graduates of family practice residency programs.

In 1979 the American Academy of Family Physicians, as the first phase of a long-range study of family practice residency outcomes, surveyed graduates for the years 1970 through 1978 who were diplomates of the American Board of Family Practice. This report is limited to an overview analysis of the hospital admission and practice privileges of the 3,021 respondents actively practicing family medicine in the United States. A higher percentage of respondents in census regions west of the Mississippi River were more likely to have privileges in obstetrics and surgery than were respondents in eastern regions. Respondents in nonmetropolitan areas were more likely to have hospital privileges than were respondents in metropolitan areas.

Family Practice↗

Improvements to assisted distillation cleanup of pesticide residues in animal fats.

The assisted distillation technique, which was developed for the cleanup of pesticide residues from animal fats, has been improved. Nitric acid cleaning of distillation tubes resulted in a significant improvement in the recoveries of hexachlorobenzene (HCB) and lindane (from 76 to 92% and 84 to 89%, respectively). A larger U-tube condenser was developed that condensed 100% of all pesticides studied. With this new condenser, a study of distillation tube flow rates showed that pesticide recoveries at 600 mL nitrogen/min were generally better than those obtained at any other flow rate although recoveries were satisfactory at 400 and 800 mL/min. Recoveries of pesticides at distillation temperatures of 210-240 degrees C were obtained with tubes cleaned with nitric acid, and using the larger U-tube condenser. The distillation temperature of choice was again 230 degrees C because there was little variation from 220 to 240 degrees C.

Adipose Tissue↗

Investigation and simplification of the sweep co-distillation cleanup of pesticide residues in animal fats.

The sweep co-distillation technique of Storherr et al. was investigated and simplified. Six organochlorine pesticides in animal fats were cleaned up under various distillation conditions as follows: No solvent was used, or solvent injection rates were 1 mL/min or 2 mL/3 min. Distillation tubes of 6.7 and 9.0 mm id diameter were compared. Distillation temperatures were varied from 150 to 300 degrees C. The complex condenser of Storherr et al. was compared with a simpler pipet condenser. A U-tube condenser which allows direct introduction onto a Florisil column for secondary cleanup was evaluated. The following modifications to the sweep co-distillation technique resulted: no solvent introduction, distillation temperature 230 degrees C, nitrogen flow rate 600 mL/min, 6.7 mm id distillation tubes with simplified packing, and incorporation of the U-tube condenser. The new technique gave recoveries comparable to those of Storherr et al., but it is faster than most bisolvent partition methods and no large volumes of solvent are required.

Animals↗

Adolescent care.

The very nature of growing up and experiencing adolescence is perplexing to each individual as well as to his/her family. Any physician dealing with adolescents needs to be keenly aware of the importance of developing a quality physician-patient relationship. This takes an understanding of the physical and emotional components of the individual, showing concern for the patient, allowing for confidentiality to enhance trust in the relationship, and getting the adolescent involved in his/her own care. The use of a questionnaire for adolescent patients can be helpful in developing those aspects of care that often lead to a quality relationship.

Adolescent↗