Biomedical subjects
Publications and source records attributed to J L Simmons.
A case of primary ileal ulceration with local perforation is presented. Infectious, hormonal, and traumatic causes are discussed with regard to the current medical literature. The majority of patients with ileal ulceration require operation for complications, including perforation, bleeding and obstruction. Resection of the involved segment of intestine with primary reanastomosis is recommended.
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Computed tomography and angiography were performed in two patients with ileal carcinoid tumor and in one with retractile mesenteritis. In each instance, a low density right lower quadrant mass with small bowel displacement and thickened mesenteric neurovascular bundles was identified at CT. Superior mesenteric artery (SMA) angiography revealed contraction, kinking and irregularity of mesenteric branches in all cases, but specific histologic diagnosis was not established by angiography alone. Our preliminary experience suggests that SMA angiography may not always be necessary in the diagnosis of either carcinoid tumor or retractile mesenteritis.
For ten years, a 25-year-old immune-competent man experienced a progressive disseminated infection with the saprophytic soil fungus, Curvularia lunata, following presumptive cutaneous inoculation while playing football. Deep, soft tissue abscesses, pulmonary suppuration, paravertebral abscess, and cerebral abscess all followed leg ulcers from neglected abrasions. The patient's delay in obtaining treatment was partially responsible for the paravertebral-mediastinal-pleural-cutaneous fistula that resulted. The importance of prompt and aggressive surgical drainage procedures is clear. Infection was arrested only by surgery. The fungus was inhibited by miconazole nitrate and amphotericin B but it developed resistance to flucytosine. Miconazole appeared to cause resolution of the cerebral abscess. Amphotericin B (1 mg/kg/day) clearly was beneficial but only after effective drainage procedures were done. The patient refused to continue amphotericin B after 5.4 g had been given in two treatments. He became bedridden one year later from back pain that was caused by recurrent disease.
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Groups of Swiss ICR mice were fed 1000 ppm polybrominated biphenyls (FireMaster BP-6) in rodent chow for 4, 8, 11, and 14 days. Control groups were fed standard rodent chow without FireMaster BP-6. Animals were killed at the end of each feeding period and the livers examined by electron microscopy. EM changes noted were progressive increase in size of hepatocytes, a decrease in rough endoplasmic reticulum, a marked increase in smooth endoplasmic reticulum, mitochondrial degeneration, increased lysosomes, and a decrease in glycogen. In addition, there was increasing proliferation of microvilli in bile canaliculi with increasing feeding times. A group of mice fed 1000 ppm FireMaster BP-6 in rodent chow for 11 days had livers with a mean of 13.93% of total body weight as compared with 6.49% for the control group (P=0.02). Tissue distribution following ingestion of 100 ppm FireMaster BP-6 for 14 days was studied. Twelve weeks post-feeding, the tissue concentrations of hexabromobiphenyl in order of highest concentration to lowest were as follows: perithymic fat, perirenal fat, adrenal glands, thymus gland, liver and stomach.
Phencyclidine (PCP) is a dissociative veterinary anesthetic and tranquilizer that at present is being abused as a psychedelic and hallucinogenic agent with increasing frequency. The cases of two young patients suffering from phencyclidine toxicity are reported. In each, central nervous system depression was accompanied by an acute dystonic motor reaction resulting in acute rhabdomyolysis and myoglobinuria. Skeletal muscle injury was felt to be the result of excessive involuntary isometrimc motor activity rather than a direct effect of phencyclidine on skeletal muscle. Patients suffering from phencyclidine intoxication should be screened for acute rhabdomyolysis. Phencyclidine intoxication should be included in the differential of nontraumatic rhabdomyolysis and should be considered among the potential causes of acute myoglobinuric renal failure.
A basal cell adenoma of parotid, eccrine dermal cylindromas and trichoepitheliomas occurring in the same patient were examined by light and electron microscopy and histochemistry. The eccrine and parotid adenomas were similar both structurally and histochemically except for the presence of Langerhans cells in the cutaneous adenoma and well differentiated mucinous cells in the parotid tumor. The three different hamartomas found in this individual may represent the effect of a single pleiotropic gene acting on ontogenetically related stem cells.
Incubation of HeLa cells in the presence of millimolar concentrations of propionate, butyrate, or pentanoate increases the specific activity of CMP-sialic acid:lactosylceramide sialyltransferase 7-20-fold within 24 h. Longer-chain saturated fatty acids or acetate are much less effective, decanoate showing no induction. Unsaturated fatty acid analogs of butyrate and other compounds are ineffective. Only the three most effective compounds also produce characteristic smooth extended cell processes in HeLa cells. Butyrate (5 mM) induces the sialyltransferase after a 4-h lag, producing maximum specific activity by 24 h. The amount of sialyl-lactosylceramide, the glycolipid product of the enzyme, increases during that time 3.5 times more than in control cultures. No other glycosphingolipid enzyme is significantly altered by butyrate exposure. The cellular shape changes occur 2-3 h later than the increase of sialyltransferase activity, and both processes require the continuous presence of inducer and the synthesis of RNA and protein but not the synthesis of DNA or the presence of serum.
The inhibitory effect of lipophilic acids, antimicrobial food additives, and analgesics-antipyretics was examined at concentrations from 0.1 to 100 mM in bacteria (Bacillus subtilis and Escherichia coli) and mammalian cells (HeLa, human fibroblasts, and mouse neuroblastoma cells). Most compounds inhibit the growth of HeLa cells about as efficiently as that of B. subtilis. However, butyrate and propionate, as well as acetaminophen, antipyrene, phenacetin, and salicylamide, inhibit HeLa at millimolar concentrations whereas, at least 10 times higher concentrations are needed to inhibit B. subtilis. The concentrations needed to inhibit growth by 50% decrease with increasing octanol-water partition coefficients of the compound. Growth of E. coli is inhibited similar to that of B. subtilis by all compounds except butylbenzoate, decanoate, and linoleate which cannot penetrate the lipopolysaccharide layer. All growth inhibitors inhibit amino acid uptake into bacteria and their vesicles, and oxygen consumption in bacteria. In HeLa cells or human fibroblasts, neither amino acid uptake nor adenine 5'-triphosphate synthesis are inhibited by fatty acids at concentrations that completely inhibit growth. Short chain fatty acids (propionate, butyrate, and pentanoate) induce in HeLa the formation of cell processes. In neuroblastoma cells, grown in the presence of 10% fetal calf serum, butyrate also induces such processes which slowly continue to grow in length for at least 7 days; these processes differ in speed of formation, width, and cycloheximide susceptibility from the thin processes produced by serum deprivation alone.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The utility of ultrastructural evaluation of eosinophilic renal cell neoplasms is illustrated by two case studies. The differential diagnosis between granular renal cell carcinoma and renal cell oncocytoma may be difficult. Ultrastructural demonstration of the presence of abundant mitochondria is useful in the definitive diagnosis of fine-needle aspiration specimens, those neoplasms with nuclear pleomorphism, or in patients requiring renal parenchymal sparing surgery.
Renal angiomyolipomas are common in patients with tuberous sclerosis complex (TSC), and the risk of severe haemorrhage from these angiomyolipomas can become substantial. This case illustrates a potentially life-threatening condition due to the development of a large aneurysm within an angiomyolipoma, which was discovered within 14 months of her screening renal ultrasound scan. Renal arterial embolisation and renal sparing surgery resulted in good recovery. Clear guidelines for the screening, surveillance, and treatment of angiomyolipomas in patients with TSC are required. This includes the appropriate frequency of surveillance for patients in different age groups and at different stages of angiomyolipoma development, based on a growing knowledge of the natural history of this condition, since growth of renal angiomyolipomas can be rapid and asymptomatic. Computed tomography or magnetic resonance imaging may be required to demonstrate complications in large lesions, as three ultrasound examinations in this patient failed to detect the large aneurysm which had developed. Angiogenesis inhibitors could potentially play a role in preventing the development of angiomyolipomas, which could improve the prognosis for patients with TSC and therefore warrants investigation through phase II/III clinical trials.