Angioleiomyoma: An unusual diagnosis for a lump in the cheek

Buccal swellings such as fibroepithelial polyps and granulomas are commonly seen in any oral diagnostic clinic, but occasionally an unusual mass presents. We describe a rare case of a man with a four-year history of a slowly enlarging, painless buccal mass that was confirmed histologically as an angioleiomyoma. Deep dissection to excise the mass completely caused no damage to nerves and there has been no recurrence.     

Nonosmotic diabetic cataracts

It has been suggested that sugar cataracts associated with diabetes mellitus result from the accumulation of excess sorbitol within lens fibrils. Swelling of lens fibrils occurs when water moves in to maintain osmotic balance; the excess water causes disruption of fibrils and cataract formation. Other studies have indicated that more than sorbitol-induced osmotic stress is involved. Our study used lenses collected from rats after 21 or 44 d of streptozotocin diabetes. Cataracts formed in untreated 44-d streptozotocin diabetic rats, but were not apparent in the 21-d untreated diabetic animals. Lens sorbitol increased in the diabetic animals both before and after cataract formation. Lens taurine varied inversely with the sorbitol content in a fashion that resulted in no net change in total lens osmoles. Lens water did not increase in the diabetic animals with or without cataracts. The aldose reductase inhibitor Sorbinil prevented the increase in lens sorbitol in both the 21- and 44-d streptozotocin diabetic rats; cataract formation was prevented in the 44-d diabetic animals. The lens water in untreated diabetic animals with cataracts did not differ from lens water in the Sorbinil-treated diabetic animals that did not develop cataracts. Sorbinil treatment of diabetic animals was associated with normalization of both lens sorbitol and taurine levels. Taurine has been shown to serve both as an osmoregulator and as an antioxidant. The apparent increase in lens osmolality attributed to sorbitol was counterbalanced by an equimolar reduction in taurine concentration. The reciprocal relationship between taurine and sorbitol reduces the likelihood of an osmotic mechanism for sugar cataractogenesis; the reduced lens taurine, however, may increase the risk of lens protein oxidation and subsequent cataract formation. Thus in vivo sugar cataract formation may be an oxidative process rather than an osmotic phenomenon.     

Growth and characterization of rabbit corneal cells in vitro

Primary organ cultures of rabbit corneal epithelium, stroma, and endothelium were established by microdissection. Secondary cultures of epithelial cells, keratocytes, and endothelial cells were established by serial passage. The doubling time for epithelial cells and keratocytes was 18 h, and endothelial cells doubled their number in 5 days. Ultrastructural studies demonstrated characteristic morphological, nuclear, and cytoplasmic features of corneal epithelial cells, keratocytes, and endothelial cells and confirmed the identity of the cell lines. The purity of the three distinct cell types was ascertained by indirect immunofluorescence techniques, using antibodies against keratin, which identified epithelial cells, and fibronectin, which identified keratocytes and endothelial cells. The indirect immunofluorescence technique represents a simple method to screen an aliquot of a cell suspension and determine the purity of corneal cells grown in vitro.     

Structure and expression of human dihydropteridine reductase.

Dihydropteridine reductase (DHPR; EC 1.6.99.7) catalyzes the NADH-mediated reduction of quinonoid dihydrobiopterin and is an essential component of the pterin-dependent aromatic amino acid hydroxylating systems. A cDNA for human DHPR was isolated from a human liver cDNA library in the vector lambda gt11 using a monospecific antibody against sheep DHPR. The nucleic acid sequence and amino acid sequence of human DHPR were determined from a full-length clone. A 112 amino acid sequence of sheep DHPR was obtained by sequencing purified sheep DHPR. This sequence is highly homologous to the predicted amino acid sequence of the human protein. Gene transfer of the recombinant human DHPR into COS cells leads to expression of DHPR enzymatic activity. These results indicate that the cDNA clone identified by antibody screening is an authentic and full-length cDNA for human DHPR.     

Endotoxin tolerance differentially alters hemodynamic responses to a thromboxane A2 mimetic and phenylephrine.

Repeated sublethal doses of endotoxin render rats tolerant to lethal doses of endotoxin and reduce thromboxane (Tx) A2 synthesis. Endotoxin-tolerant rats are also more resistant to lethal doses of U46619, a stable TxA2 mimetic. These observations raised the possibility that tolerance may alter hemodynamic responses to TxA2 via one or more mechanisms. Mean arterial pressure (MAP) responses to i.v. injections of the stable TxA2 mimetic U46619 at doses ranging from 0.17 to 8.4 micrograms/kg were determined. Despite an initial lower systemic vascular resistance in tolerant rats compared to control rats (2.4 +/- 0.3 vs 3.1 +/- 0.2 mm Hg/ml/min/100 g of body weight, respectively, p less than 0.05), the maximum pressor response to U46619 was significantly greater (p less than 0.05) at the higher doses of U46619 in tolerant rats compared to control rats. Tolerant and control rats also exhibited qualitatively different changes in MAP in response to U46619. Control rats manifested an initial hypotensive response (15 s) not observed in tolerant rats. In contrast, tolerant rats exhibited no depressor response, but a higher peak pressor response to U46619 than that seen in controls. Since prostaglandins may modulate vascular responses to U46619, subsequent studies were conducted in indomethacin-pretreated or essential fatty acid (EFA) deficient rats that were depleted of arachidonic acid substrate. Either indomethacin or EFA deficiency significantly prevented the initial hypotensive response in control rats, suggesting that prostaglandins may mediate this response to U46619. In additional studies, the MAP response in tolerant and control rats to the alpha 1-adrenergic agonist phenylephrine was determined.(ABSTRACT TRUNCATED AT 250 WORDS)     

Clinical performance of endoprosthetic and total hip replacement systems

A retrospective study of endoprosthetic replacements and total hip prostheses was undertaken to determine factors that have the greatest effect on the success or failure of femoral hip components. A total of 227 endoprostheses were inserted within the years 1970-1985. Of these, 67 components (29.5 percent) required removal for various reasons. For an endoprosthesis, the most significant factor in determining the chances of success appeared to be the initial insertion diagnosis. Patients who received an endoprosthesis for an ailment which affected only the femoral side of the joint (such as traumatic fracture) had a much lower rate of failure than those patients with disease etiologies that could affect the acetabulum (such as osteoarthritis). The opposite was found for total hip prostheses. Of the 641 total hip devices inserted, 148 (23.0 percent) required removal. The highest rate of failure among these total hip components was for those devices inserted for trauma and the lowest rate of failure was for those inserted for osteoarthritis. Age at the time of insertion also proved to be of importance when estimating a hip component's chance of survival. For both endoprosthetic replacements and total hip arthroplasties, patients younger than 50 years of age at insertion experienced a failure rate almost twice that of those patients more than 50 years of age at insertion.     

Synthesis, antimalarial activity, and quantitative structure-activity relationships of tebuquine and a series of related 5-[(7-chloro-4-quinolinyl)amino]-3-[(alkylamino)methyl] [1,1'-biphenyl]-2-ols and N omega-oxides

A series of 5-[(7-chloro-4-quinolinyl)amino]-3-[(alkylamino)methyl] [1,1'-biphenyl]-2-ols and N omega-oxides was prepared from the substituted 1-phenyl-2-propanones proceeding through the 5-nitro[1,1'-biphenyl]-2-ols, the corresponding amino, and acetamido derivatives to the N-[5-[(alkylamino)methyl]-6-hydroxy[1,1'-biphenyl]-3-yl]acetamides and final condensation with 4,7-dichloroquinoline or the N-oxide. In a quantitative structure-activity relationship study first run on 28 and later expanded to 40 substituted phenyl analogues and their N omega-oxides, increasing antimalarial potency vs. Plasmodium berghei in mice was found to be correlated with decreasing size (sigma MR) and electron donation (sigma sigma) of the phenyl ring substituents. A significant correlation with N omega-oxidation could not be demonstrated. Initial high activity against P. berghei infections in mice led to expanded studies that demonstrated in addition excellent activity against resistant strains of parasite, activity in primate models, and pharmacokinetic properties apparently allowing protection against infection for extended periods of time even after oral administration. Such properties encourage the clinical trial of a member of this class in man.