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Biomedical subjects

J F Johnson

Publications and source records attributed to J F Johnson.

At least 37 records · Page 2Linked to original sources
PubMed1990

Symptomatic hypoglycemia secondary to a glipizide-trimethoprim/sulfamethoxazole drug interaction.

Sulfonamides have been reported to augment the hypoglycemic effects of chlorpropamide, glyburide, and tolbutamide. This case report is the first to describe a possible interaction with glipizide. An 83-year-old man receiving glipizide 10 mg bid developed symptomatic hypoglycemia within three days of adding trimethoprim/sulfamethoxazole (TMP/SMX) to his regimen. All other factors, including laboratory data, dietary intake, activity level, and concurrent use of other medications, were stable and noncontributory. This patient may have been at increased risk for this interaction secondary to his age and history of alcohol abuse. The mechanism of the interaction is probably inhibition of glipizide metabolism rather than protein-binding displacement. This case suggests that, when TMP/SMX is combined with glipizide, patients should be closely monitored, especially those at high risk for hypoglycemia.

Aged↗
PubMed1989

Chronic torsion of the wandering spleen.

Torsion of a wandering spleen can occasionally produce chronic disabling clinical findings that are mistaken for a variety of digestive disturbances. Since the clinical complaints are misleading, a correct and timely radiographic analysis can prevent an extensive but unnecessary pursuit of other more common conditions. Images of an ectopic, enlarged, disoriented spleen with a devitalized parenchyma and adherent pseudocapsule can quickly establish the diagnosis of chronic splenic torsion.

Chronic Disease↗
PubMed1989

Ileocolic intussusception: new sign on the supine cross-table lateral radiograph.

The ability to detect ileocolic intussusception on the supine cross-table lateral radiograph of the abdomen in infants was prospectively evaluated in 12 cases (including two recurrences) over a 2-year period. The intussusceptions (including one recurrence) were directly depicted on five radiographs as a homogeneous water-density mass producing a convex interface with bowel gas at the anterior part of the abdomen. In another four patients, the intussusception produced an inappropriate craniocaudal separation of gas-filled bowel loops in the upper part of the abdomen, caudal to the liver shadow. The intussusception was prospectively recognized on the supine cross-table lateral radiograph in nine of 12 cases.

Gases↗
PubMed1989

Gastric inflammatory pseudotumor in children.

Gastric inflammatory pseudotumors have radiographic, surgical, and histologic features that simulate malignant tumors. To avoid inappropriately aggressive therapy, it is important to know when to consider this diagnostic possibility preoperatively. The cases of two children with gastric inflammatory pseudotumors are presented to emphasize three findings in this entity: (a) An inflammatory pseudotumor should be considered if a gastric mass encompasses an ulcer or a confined gastric perforation. (b) Other unusual inflammatory responses associated with a gastric mass, such as sclerosing cholangitis and retroperitoneal fibrosis, should suggest the diagnosis. (c) Inflammatory pseudotumor is the most likely cause of a gastric mass in a child with Castleman syndrome.

Child↗
PubMed1988

Diffuse neonatal gastric infarction.

Diffuse neonatal gastric infarction can be a devastating complication of invasion of the gastric wall and vessels by fungi colonizing the gastric mucosa. Even in the presence of extensive transmural necrosis, however, the radiographs do not necessarily show evidence of gastric mucosal abnormality. Instead, plain films and positive contrast studies may erroneously suggest a mechanical gastric outlet obstruction. Ancillary evidence of a devitalized viscus in a baby who appears to have complete gastric outlet obstruction should suggest the diagnosis of gastric infarction.

Candidiasis↗
PubMed1988

Pneumatosis in the descending colon: preliminary observations on the value of prone positioning.

Prone positioning is valuable for accurate diagnosis of intramural air in the descending colon. In the supine position, partial collapse of the descending colon can minic intramural air. Conversely, complete collapse of the descending colon eliminates the interface between intraluminal and intramural air so that the recognition of intramural air is obscured. The tendency for the descending colon to distend with gas in the prone position may reduce these false positives and negatives for intramural air.

Air↗
PubMed1988

Sodium dodecyl sulfate-gel electrophoresis: staining of polypeptides using heavy metal salts.

Water-soluble salts of several heavy metals were examined for their ability to stain polypeptides resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Brief gel exposure (5 min or less) to cobaltous acetate or chlorides of copper, nickel, and zinc produced negatively stained protein patterns that were qualitatively indistinguishable from those of parallel gels stained with Coomassie blue R-250. Protein patterns could be visualized less than 1 min after treatment of gels with zinc chloride; the threshold of detection was estimated at about 10-12 ng protein on standard-size slab gels. Test samples including human erythrocyte membranes, sialoglycoprotein (glycophorin) extracts, and commercial molecular weight protein standards were used to establish the scope of these stains. Protein patterns visualized by the heavy metal salts were compared and contrasted with profiles seen with three widely used silver stains. Proteins from gels treated with copper or zinc chloride could be easily recovered by simple diffusion; this makes feasible both analytical and preparative electrophoretic applications of the staining procedure. A mechanism is proposed to explain the observed protein staining by heavy metal salts.

Copper↗
PubMed1988

The sensitivity of plain films for detecting perforation in children with appendicitis.

The plain films of 37 patients under age 18 with surgically and pathologically proven non perforated (16/37) and ruptured (21/37) appendicitis were reviewed in order to determine the ability of the plain film to specify perforation. Perforation was suggested when one or more of the following six findings were clearly defined: 1. Acute small bowel obstruction. 2. Extraluminal gas. 3. Mass in the right lower quadrant. 4. Colon cut-off sign at the hepatic flexure. 5. Fecalith. 6. Obliteration of the pelvic fat planes. This approach resulted in a sensitivity of 80% and a specificity of 94%, with the only false positive for perforation occurring in a patient with a fecalith. In five patients, extraluminal gas produced a triangular accumulation in the right flank which could be distinguished from intraluminal bowel gas on the supine or prone film.

Adolescent↗
PubMed1987

Bleomycin nodules mimicking metastatic osteogenic sarcoma.

Patients with osteogenic sarcoma are at a very high risk of developing pulmonary metastatic disease. Bleomycin has recently been reported to cause pulmonary nodules mimicking metastatic disease. Our case adds what we believe to be the first report in the pediatric literature and describes new findings that we believe are so suggestive of bleomycin nodules that immediate biopsy to exclude metastatic disease may not be necessary.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1986

Ileocolic intussusception: hydrostatic reduction in the presence of the dissection sign.

Hydrostatic reduction of an ileocolic intussusception has not been reported when barium dissects around the intussusceptum as opposed to pushing it retrograde. Consequently, this development is considered an indication to discontinue hydrostatic reduction. We have studied a baby in whom draining the colon caused a seemingly irreversible dissection of barium to disappear so that hydrostatic reduction of the intussusception was easily accomplished when the colon was refilled with barium.

Female↗
PubMed1986

Concealed pulmonary abscess: diagnosis by computed tomography.

During childhood, an acute pneumonia with bulging margins usually reflects an abundant production of exudate. However, an unexplained persistence of an expansile pneumonia following therapy indicates that the infectious process may be isolating itself by forming an abscess. Previous reports emphasize that such abscesses are rarely diagnosed prior to thoracotomy or autopsy. Computed tomography facilitates an earlier disclosure of an abscess or empyema that is producing a persistent but unexplained expanding opacification on plain film.

Adolescent↗
PubMed1985

Infantile infectious sacroiliitis.

Two infants with pyogenic sacroiliitis are presented. In both babies, the clinical findings were initially attributed to septic arthritis of the ipsilateral hip. The correct diagnosis was not established in either infant until radionuclide scanning showed increased uptake in the ipsilateral sacroiliac joints. Both cases emphasize the importance of proceeding quickly to radionuclide imaging in the baby with clinical and laboratory findings of inflammation in the vicinity of the hip and a negative hip aspiration.

Arthritis, Infectious↗