Nonrandom structural features in the heparin polymer

Computer simulation studies were used to prepare an ensemble of heparin number chains. The polydispersity of these chains was simulated by introducing a specific "fraction of terminators", and it closely resembled the experimentally observed polydispersity of a porcine mucosal, glycosaminoglycan heparin. The same percentage of simulated chains contained antithrombin III (ATIII) binding site sequences as are typically found to contain ATIII binding sites using affinity chromatography. Heparin lyase action was then simulated by using Michaelis-Menten kinetics. In one model, heparin chains were constructed from the random assembly of monosaccharide units using the observed mole percentage of each. After simulated depolymerization, the final oligosaccharides formed were compared to the observed oligosaccharide products. The simulation which assumed a random distribution of monosaccharide units in heparin did not agree with experimental observations. In particular, no ATIII binding site sequences were found in the simulated number chains. The results of this simulation indicate that heparin is not simply a random assembly of monosaccharide units. These results are consistent with the known, ordered biosynthesis of heparin. In a second model, heparin chains were constructed from randomly assembled oligosaccharides at the mole percentage in which each is found in the final product mixture. The action of heparin lyase was then simulated, and the distribution of the oligosaccharide products was measured throughout the simulated time course of the depolymerization reaction. The simulated rate of formation and final concentration of a particular oligosaccharide which contains a portion of heparin's ATIII binding site were similar to those observed experimentally. These results are consistent with the random distribution of ATIII binding sites within glycosaminoglycan heparin.(ABSTRACT TRUNCATED AT 250 WORDS)

Maxillary metastasis of transitional cell carcinoma: report of a case

Metastases to the maxilla are extremely rare, and only 64 cases of histologically proven maxillary metastases can be found in the English-language literature. This article reports the first case of metastatic transitional cell carcinoma of the urinary bladder to the maxilla. The distribution of proven cases of maxillary metastasis and the possible anatomic pathways for this metastasis are discussed.

Histological characteristics associated with suppurating periodontal pockets

The purpose of this study was to characterize histologically the gingival lesion associated with suppuration in advanced periodontitis. Thirty-three bleeding, suppurating (S) and 23 bleeding, nonsuppurating (NS) interproximal biopsies were obtained from nine patients and processed for light microscopy. Pocket depths (mean +/- SD) were 6.7 +/- 1.6 mm (S) and 5.4 +/- 2.2 mm (NS). Six-micron serial sections were stained with (1) hematoxylin/eosin and (2) van Gieson. Quantitative cell types were determined by a grid intersection counting technique at x 1000. Volumetric analysis of collagen-poor (inflammation) areas was conducted using a computer biometric system that revealed three histologic patterns: Type I sites showed mild to moderate inflammation (less than 50% infiltrate, S = 15, NS = 20); Type II sites showed intense inflammation (greater than 50% infiltrate, S = 17, NS = 3); and only one (S) site had a large connective tissue abscess (Type III). The mean percentage of collagen-poor area was significantly larger in suppurating (42.1 +/- 25.5%) versus nonsuppurating (27.7 +/- 20.4%) sites (P = 0.02). In both S and NS sites, plasma cells (means = 66%) and lymphocytes (means = 27%) predominated in the inflammatory infiltrates. Histologically, suppuration appeared to be associated with increased gingival inflammation and a slight increase in connective tissue neutrophils.

Concurrent anomalies: cheilitis glandularis and double lip. Report of a case

Double lip and cheilitis glandularis are uncommon anomalies involving the minor salivary glands of the lip. A unique case of concurrent double lip and cheilitis glandularis is presented. The development, diagnosis, and treatment of both lesions are reviewed. Their concurrent development in this patient appears to be unrelated.

Dosimetric calculations and measurements of gold plaque ophthalmic irradiators using iridium-192 and iodine-125 seeds

The dosimetry of ophthalmic plaques designed to hold iridium-192 or iodine-125 seeds is investigated experimentally and by means of a computer model. A phantom for thermoluminescent dosimetry (TLD) which permits measurements to within 2 mm of the plaque surface is described. TLD data are compared with model calculations that take into account the active length of the seeds, anisotropy of dose distribution from single seeds, and scatter within the phantom. An isotropic point source calculational model is accurate for clinical calculations, particularly at depths greater than 5 mm. Relative central axis dose measurements for 125I in a gold plaque are also in agreement with the model. Comparisons of 192Ir, 125I and 60Co plaques are presented. The relative advantages of using these isotopes in eye plaques are discussed.

The IC model of parallel computation and programming environment

The IC* project is an effort to create an environment for the design, specification and development of complex systems such as communication protocols, parallel machines and distributed systems. The basis of this work is the IC* model of parallel computation. In this model a system is specified by a set of invariant expressions which describe its behavior in time. The novel features of the model include: temporal and structural constraints, inherent parallelism, explicit modeling of time, nondeterministic evolution and dynamic activation. The project also includes the construction of a parallel computer specifically designed to support the model of computation. The model of computation, the status of the project and the user environment is the content of this paper.

Acrocephalopolysyndactyly type II--Carpenter syndrome: clinical spectrum and an attempt at unification with Goodman and Summit syndromes

Carpenter syndrome (ACPS type II) was first described by Carpenter in 1901. The syndrome consists of acrocephaly, soft tissue syndactyly, brachy- or agenesis mesophalangy of the hands and feet, preaxial polydactyly, congenital heart disease, mental retardation, hypogenitalism, obesity, and umbilical hernia. Here we review the literature on Carpenter syndrome and add 2 affected sibs with marked intrafamilial variability. This review showed that 2 reported variations of Carpenter syndrome, Goodman and Summitt syndromes, actually fall within the clinical spectrum of this disorder. This confirms earlier suggestions of Gorlin (personal communication 1982) and Hall et al [Am J Med Genet 5:423-434, 1980].

The IC system for protocol development

The realization of a new protocol is a long and complicated procedure whose inherent technical difficulty is exacerbated by the scarcity of useful tools. This paper discusses the initial use of a system that is being developed by Bell Communication Research to help in the specification, analysis, and implementation of communications protocols. This paper describes the application of this system to the specification and implementation of an industry standard protocol.

Management of a common oral lesion of the elderly

Lichen planus of the oral cavity produces significant functional and symptomatic problems for elderly patients. Oral lesions often occur in the absence of concomitant skin lesions. Unlike cutaneous lesions, oral lesions of lichen planus may become a chronic, recurring problem that is difficult to control. The diagnostic features of lichen planus of the oral cavity are reviewed and treatment strategies presented. Periodic follow-up is recommended to monitor the disease process and to observe for the development of early squamous cell carcinoma.

Intraoral osseous and cartilaginous choristomas: report of three cases and review of the literature

Intraoral osseous and cartilaginous choristomas are rare lesions, with only 72 cases previously reported in the literature. Three additional cases are presented, and the literature is reviewed. One case represents the first reported osseous choristoma on the retromolar pad.

Mylohyoid herniation: gross and histologic evaluation with clinical correlation

The purpose of this study was to further document the presence of a mass herniating inferiorly through the mylohyoid muscle into the submandibular area, to identify the mass histologically, and to discuss its importance in a differential diagnosis of masses in this area. A mass that perforated the mylohyoid muscle was found in 45 of the 100 cadavers studied. These 45 cadavers contained a total of 63 herniations. Of the 60 male cadavers, 26 (43.33%) showed herniation, and 19 (47.50%) of the 40 female cadavers showed herniation. Histologic evaluation of the 63 biopsy specimens revealed the following: 30 herniating masses (47.61%) were of the sublingual gland; 28 (44.44%) were of the submandibular gland; 4 (6.34%) were composed of pure adipose tissue, and 1 (1.58%) was a cholesteatoma. Inflammation was found in 46 (73.00%) of the biopsy specimens, consisting of sclerosing sialoadenitis in 30 specimens (47.61%) and a mild chronic inflammatory infiltrate in 16 specimens (25.39%).

Synthesis of novel angiotensin converting enzyme inhibitor quinapril and related compounds. A divergence of structure-activity relationships for non-sulfhydryl and sulfhydryl types

The synthesis and angiotensin converting enzyme (ACE) inhibiting activities of quinapril (CI-906, 22), its active diacid (CI-928, 33), and its dimethoxy analogue (CI-925, 25) are reported. These tetrahydro-3-isoquinolinecarboxylic acid derivatives possess equivalent in vitro potency and in vivo efficacy to enalapril. Sulfhydryl analogues with the same structural variation are also highly potent. In contrast, tetrahydro-1-isoquinolinecarboxylic acid and homologous isoindoline-1-carboxylic acid analogues show a striking divergence in potency between the two types, sulfhydryl analogues being essentially inactive, while non-sulfhydryl analogues are equipotent with the proline prototype. This is the first evidence suggesting that alternate binding modes may exist for the two major structural classes of small molecule ACE inhibitors.

CI-926 (3-[4-[4-(3-methylphenyl)-1-piperazinyl]butyl]-2,4-imidazolinedione): antihypertensive profile and pharmacology

CI-926 (10(-7)-10(-6) M) selectively antagonized the contraction of isolated rabbit aortae to phenylephrine and displaced the alpha-1 adrenoceptor ligand WB4101 (IC50: 82 nM) in rat brain. In the spontaneously hypertensive rat, single oral doses of either CI-926 (0.3-10 mg/kg) or prazosin (0.3-100 mg/kg) caused dose-related reductions in blood pressure; however, CI-926 was more efficacious. The maximal antihypertensive response to CI-926 was unchanged with three consecutive days of oral dosing in the spontaneously hypertensive rat, whereas a first dose effect was noted with prazosin. In two-kidney, one-clip, renal hypertensive rats, CI-926 and prazosin (1-10 mg/kg) lowered blood pressure; however, prazosin was more efficacious. In perinephritic hypertensive dogs, CI-926 (10 mg/kg) lowered blood pressure 20%. In anesthetized dogs, CI-926 in the presence of supermaximal blood pressure-lowering doses of prazosin caused an additional reduction in pressure. With equivalent alpha-1 blockade in anesthetized rats, CI-926 tended to have greater hypotensive activity than prazosin. These results demonstrate that CI-926 is a potent, orally active antihypertensive agent in renin-dependent and -independent hypertension. The profile of CI-926 suggests that it lowers blood pressure in part by interacting with peripheral alpha-1 adrenoceptors and in part via an additional mechanism(s). Although weak relative to its affinity for alpha-1 adrenoceptors, CI-926 was found in preliminary experiments to interact with alpha-2 adrenoceptors, serotonergic receptors and dopaminergic receptors. The importance of these interactions to the blood pressure response of CI-926 remains to be elucidated.

Laser catheter-induced atrioventricular nodal delays and atrioventricular block in dogs: acute and chronic observations

Selective modification of atrioventricular (AV) nodal conduction, that is, induction of varying degrees of AV nodal delays or block (second or third degree), or both, was achieved with a pervenous laser catheter technique. In six adult mongrel dogs anesthetized with pentobarbital (Nembutal), 5F leads were placed through femoral and external jugular veins and placed into the right atrium and His bundle region. Through another femoral vein, a 200 micron optical fiber was inserted by way of a 7F catheter with a preformed curved tip. Guided by fluoroscopy and His bundle electrograms, the fiber's tip was positioned in the AV nodal region. After autonomic blockade was achieved with intravenous propranolol (5 mg) and atropine (1 mg), AV conduction was analyzed. An argon laser delivered 3 to 4 watts into the fiber in bursts of 10 seconds' duration until the desired degree of AV nodal delay or block (second or third degree) was manifested. Monitoring of His bundle electrograms was continued for 2 hours. Four weekly serial electrocardiograms were recorded, after which electrophysiologic studies were repeated. Acute post-lasing studies showed that: in all six dogs, the mean PR interval was prolonged from 116 ms (range 100 to 135) to 153 ms (range 120 to 185), with the prolongation being caused exclusively by AH lengthening from 68 ms (range 50 to 90) to 105 ms (range 65 to 140); the mean effective refractory period of the AV node increased from less than 185 ms (range less than 150 to less than 200) to 215 ms (range 190 to 280); and the mean atrial pacing cycle length, at which second degree AV nodal block was manifested, increased from 210 ms (range 160 to 260) to 261 ms (range 205 to 320).(ABSTRACT TRUNCATED AT 250 WORDS)

Laser recanalization of occluded atherosclerotic arteries in vivo and in vitro

Controlled laser irradiation was used to recanalize atherosclerotic stenoses in vivo and in vitro. In 15 rabbits with atherosclerotic arteries a catheter was positioned in the distal aorta for angiographic examination and as a guide for a small silica optical fiber. Both Nd-YAG and argon lasers were used for recanalization with varying power and duration. As determined by angiographic studies the severity of iliofemoral stenoses in eight 15 arteries decreased from 78 +/- 18% to 32 +/- 11% (mean +/- SD). In one additional artery the stenosis improved from 45% to 25%, but this was associated with perforation. The other six arteries were perforated (two after fiber manipulation, four after laser discharge) without obvious improvement in severity of stenosis. No angiographic loss of distal circulation was noted. To better define tissue- laser interactions in the live-rabbits, lasing of 15 totally occluded atherosclerotic rabbit arterial segments in vitro was done while the optical fiber was advanced or fixed. When the fiber was fixed, serial sections showed that the new lumen was flame shaped. The width and depth of the lumen increased with increasing laser energy. When the fiber was advanced, histologic examination showed a smooth cylindrical vascular channel with limited lateral tissue damage. This study demonstrated that lasers can recanalize atherosclerotic stenoses in a live animal preparation; however, arterial perforation remains a problem.

The effects of myocardial ischemia followed by reperfusion on perfused coronary capillarity

To determine the effects of ischemia and reperfusion on myocardial perfused capillary density, rat hearts were excised, kept ischemic for thirty minutes then reperfused with blood from a support animal. Control hearts were isolated and perfused for either 10 or 60 minutes before injection of a vascular marker (Monastral Blue-blood mixture, 30 sec at 100 mmHg). The ischemic hearts were perfused with Blue after 10 minutes of reperfusion. The perfused capillary density (theta) and capillary/fiber ratio (C/F) were measured from frozen transverse sections of the left ventricle. For 10- and 60-minute control hearts, the epicardial theta values were 2324 +/- 476 caps/mm2 and 2378 +/- 330 SD. The endo/epi theta ratio was not significantly less than unity for either control group. For the ischemic group, theta was significantly decreased both in the epicardium (707 +/- 515 caps/mm2) and endocardium (130 +/- 30 caps/mm2) (p less than 0.05). The endo/epi theta ratio was significantly less than unity for the ischemic group (P less than 0.05). The C/F ratio analysis yielded the same results. The decrease in both theta and CF ratio indicate that 30 minutes of ischemia followed by 10 minutes of reperfusion caused a marked "No-reflow" phenomena in isolated, supported hearts. The No-reflow was most pronounced in the endocardium.

C-peptide and insulin secretion. Relationship between peripheral concentrations of C-peptide and insulin and their secretion rates in the dog

Estimation of the insulin secretory rate from peripheral C-peptide concentrations depends upon the following characteristics of C-peptide kinetics: (a) equimolar secretion of insulin and C-peptide by pancreatic beta cells; (b) negligible hepatic extraction of C-peptide; (c) constant metabolic clearance rate (MCR) of C-peptide over a physiological and pathophysiological range of plasma levels; and (d) proportional changes in the secretion rate of C-peptide and its peripheral concentrations under varying physiological conditions. In the present experiments, the relationship between a variable intraportal infusion of C-peptide and its concentration in the femoral artery was explored in 12 pancreatectomized dogs. As the infusion of C-peptide was rapidly increased, the magnitude of its peripheral concentration initially increased less than the infusion rate by 20-30%. After an equilibration period of approximately 30 min, however, further increases and decreases in the intraportal infusion were accompanied by nearly proportional changes in its peripheral concentration. Estimates of the amount of C-peptide infused during the experiment based on the steady state C-peptide MCR and its peripheral concentration were within 20% of the amount of C-peptide actually infused. These experiments demonstrate that the portal delivery rate of C-peptide can be calculated from its MCR and peripheral concentration in the dog. They also provide a basis for testing the validity of more complicated models of insulin secretion based on peripheral C-peptide concentrations in the dog as well as other species, including man. Finally, we have shown that the hepatic extraction of endogenously secreted C-peptide is negligible in the basal state (3.1 +/- 6.1%), and does not change after oral glucose ingestion. The MCR of exogenous dog C-peptide was similar whether measured by constant peripheral intravenous infusion (12.3 +/- 0.7 ml/kg per min), constant intraportal infusion (13.4 +/- 0.6 ml/kg per min), or analysis of the decay curve after a bolus injection (13.5 +/- 0.7 ml/kg per min).

Pancreatic hormone profiles and metabolism posthepatectomy in the dog. Evidence for a hepatotrophic role of insulin, glucagon, and pancreatic polypeptide

Gut-related peptide hormones, especially insulin and glucagon, have been implicated in promoting hepatic regeneration. To elucidate the interrelationship between pancreatic peptide hormones and hepatic regenerative activity, we evaluated pancreatic hormone levels and their metabolism before and over a 15-day period after limited (42%) and extended (72%) hepatectomy in the dog. Serum insulin, glucagon, and pancreatic polypeptide levels increased significantly after both limited and extended hepatectomy but not after sham laparotomy. In the case of glucagon only, these increases were related to the extent of liver resection. No significant changes in plasma somatostatin levels were observed posthepatectomy. Plasma glucose levels remained normal throughout the period of study. Metabolic clearance rates and plasma half-lives for insulin, glucagon, and pancreatic polypeptide did not change over the study period. Peripheral C-peptide/insulin molar ratios were unchanged posthepatectomy, indicating no change in hepatic insulin extraction. In the absence of demonstrable changes in hormone metabolism or metabolic stimuli to secretion, these increases in pancreatic hormone levels, coinciding with the period of known maximal hepatic regenerative activity, are compatible with the notion that these are hepatotrophic responses, which could conceivably be mediated by humoral feedback signals from the liver to the endocrine pancreas.

Antihypertensive profile of the angiotensin-converting enzyme inhibitors CI-906 and CI-907

CI-906 and CI-907, new orally active nonsulfhydryl angiotensin-converting enzyme inhibitors, were examined for antihypertensive effects in unanesthetized hypertensive rats and dogs. In two-kidney, one-clip Goldblatt hypertensive rats, single oral daily doses (0.03-30 mg/kg) produced dose-dependent decreases in blood pressure; a single 3 mg/kg oral dose lowered blood pressure to normotensive levels. In spontaneously hypertensive rats, 30 mg/(kg X day) orally administered for 5 consecutive days achieved the same blood pressure decrease as that obtained on the first day in the renal hypertensive rats. In diuretic-pretreated renal hypertensive dogs, a 10 mg/kg oral dose decreased blood pressure by 25%. No adverse side effects were observed with CI-906 and CI-907 in any of the conscious animals. These studies indicate that CI-906 and CI-907 are potent, orally active antihypertensive agents without any apparent limiting side effects.

CI-906 and CI-907: new orally active nonsulfhydryl angiotensin-converting enzyme inhibitors

CI-906, [3S-[2[R*(R*)]], 3R*]-2-[2-[[1-(ethoxycarbonyl)-3-phenylpropyl]-amino]-1-oxopropyl] 1,2,3,4-tetrahydro-3-isoquinolinecarboxylic acid, monohydrochloride, and CI-907, [2S-[1[R*(R*)]], 2 alpha, 3a beta, 7a 7a beta]-1-[2-[[1-(ethoxycarbonyl)-3-phenylpropyl]amino] 1-oxopropyl]octahydro-1H-indole-2-carboxylic acid, monohydrochloride, are two new nonsulfhydryl-type angiotensin-converting enzyme (ACE) inhibitors. Monoester (prodrug) and diacid forms produced concentration-related ACE inhibition in guinea pig serum (IC50 for CI-906 = 8.3 X 10(-9) M, diacid = 2.8 X 10(-9) M; CI-907 = 1.0 X 10(-7) M, diacid = 2.6 X 10(-9) M). In isolated rabbit aortic rings and in in vivo rat and dog autonomic studies, both compounds were highly specific in suppressing the contractile or pressor responses to angiotensin I. In two-kidney, one-clip Goldblatt (renin-dependent) hypertensive rats there was a good correlation between the inhibition of vascular converting enzyme and blood pressure lowering and a poor correlation between blood pressure lowering and plasma and brain converting enzyme inhibition. Cardiovascular, pulmonary, and central nervous system performance evaluations showed no side effects or gross toxicity. The preclinical profile shows CI-906 and CI-907 to be specific, potent, orally active ACE inhibitors. They are expected to have therapeutic utility in hypertension and in any other condition where converting enzyme inhibition would be useful.