Aortic Curvature Instead of Angulation Allows Improved Estimation of the True Aorto-iliac Trajectory.

OBJECTIVE: Supra- and infrarenal aortic neck angulation have been associated with complications after endovascular aortic aneurysm repair. However, a uniform angulation measurement method is lacking and the concept of angulation suggests a triangular oversimplification of the aortic anatomy. (Semi-)automated calculation of curvature along the center luminal line describes the actual trajectory of the aorta. This study proposes a methodology for calculating aortic (neck) curvature and suggests an additional method based on available tools in current workstations: curvature by digital calipers (CDC). METHODS: Proprietary custom software was developed for automatic calculation of the severity and location of the largest supra- and infrarenal curvature over the center luminal line. Twenty-four patients with severe supra- or infrarenal angulations (≥45°) and 11 patients with small to moderate angulations (<45°) were included. Both CDC and angulation were measured by two independent observers on the pre- and postoperative computed tomographic angiography scans. The relationships between actual curvature and CDC and angulation were visualized and tested with Pearson's correlation coefficient. The CDC was also fully automatically calculated with proprietary custom software. The difference between manual and automatic determination of CDC was tested with a paired Student t test. A p-value was considered significant when two-tailed α < .05. RESULTS: The correlation between actual curvature and manual CDC is strong (.586-.962) and even stronger for automatic CDC (.865-.961). The correlation between actual curvature and angulation is much lower (.410-.737). Flow direction angulation values overestimate CDC measurements by 60%, with larger variance. No significant difference was found in automatically calculated CDC values and manually measured CDC values. CONCLUSION: Curvature calculation of the aortic neck improves determination of the true aortic trajectory. Automatic calculation of the actual curvature is preferable, but measurement or calculation of the curvature by digital calipers is a valid alternative if actual curvature is not at hand.

GSK-3ß inhibition protects mesothelial cells during experimental peritoneal dialysis through upregulation of the heat shock response.

Non-physiological components of peritoneal dialysis fluids (PDF) lead to the injury of peritoneal mesothelial cells resulting in the failure of peritoneal dialysis (PD) potentially via inadequate induction of the protective heat shock response (HSR). Glycogen synthase kinase-3ß (GSK-3ß) is a negative regulator of cell survival partly by suppression of the HSR and is influenced by stress stimuli also present in conventional PDF. The effects of PDF on GSK-3ß activation and the impact of GSK-3ß inhibition with lithium (LiCl) were investigated on cell survival with special regard to HSR, in particular to heat shock transcription factor 1 (HSF-1) activation and Hsp72 production in an in vitro model of PD using MeT-5A and primary mesothelial cells. Incubation of cells with the PDF Dianeal® (glucose-based, low pH, high glucose degradation products (GDP)) and Extraneal® (icodextrin-based, low pH, low GDP) caused activation of GSK-3ß compared to the other tested PDF, i.e. Balance®, Physioneal® (normal pH, glucose-based, low GDP) and Nutrineal® (moderately acidic, amino acid-based). Inhibition of GSK-3ß with LiCl in Dianeal® and Extraneal®-treated cells dose-dependently decreased cell damage and death rate and was paralleled by higher HSF-1 activation and Hsp72 expression. GSK-3ß is activated by low pH GDP containing PDF with and without glucose as osmotic agent, indicating that GSK-3ß is involved in mesothelial cell signalling in response to experimental PD. Inhibition of GSK-3ß with LiCl ameliorated cell injury and improved HSR upon PDF exposure. Thus, GSK-3ß inhibitors likely have therapeutic potential as cytoprotective additive for decreasing PDF toxicity.

Lipedematous alopecia.

Lipedematous alopecia is an unusual disorder characterized by short, brittle scalp hairs associated with thickening of the scalp by adipose tissue. All except one reported case have been in African-American females. It is our purpose to report the seventh case of this condition.

A Monte Carlo simulation model for radiation dose to metastatic skeletal tumor from rhenium-186(Sn)-HEDP.

UNLABELLED: A Monte Carlo model has been developed for simulation of dose delivery to skeletal metastases by the bone surface-seeking radiopharmaceutical 186Re (Sn)-HEDP. METHODS: The model simulates: (1) the heterogeneous small scale geometry of the soft tissue/bone-spicule structure in the lesions as determined by histomorphometric measurements of histologic specimens, (2) the small scale spatial distribution of the radiopharmaceutical on the lesion bone spicule surface as determined by autoradiography, and (3) the 186Re beta and conversion electron decay spectrum and the associated charged particle transport within the modeled geometries. The results are compared with the commonly employed uniform lesion model, which assumes: (1) homogeneous lesion morphology, (2) uniform distribution of radioactivity within the lesion, and (3) complete energy deposition by charged particles within the lesion due to decay of this activity. Gamma and x-ray photons from the 186Re spectrum were assumed to escape from the lesion volume in both models. RESULTS: Results show a significant dependence on the bone volume fraction and hence on the histology of the lesion (lytic, blastic or mixed). The uniform lesion model calculations underestimate the radiation dose to blastic lesions by as much as a factor of 1.8. However, for lytic lesions with low bone volume fractions, both models provide similar dose values. CONCLUSIONS: These new model calculations provide a mechanism for optimizing treatment planning and dose response evaluations of therapeutic bone-seeking radiopharmaceuticals.

Moxonidine and hydrochlorothiazide in combination: a synergistic antihypertensive effect.

This study was designed as a multicenter, double-blind, placebo-controlled, parallel-group, prospectively randomized study comparing, after a 4-week placebo run-in phase, moxonidine 0.4 mg once daily (o.d.), hydrochlorothiazide 25 mg o.d., and the combination of the two with placebo. A total of 160 patients were analyzed in an intent-to-treat analysis. Moxonidine 0.4 mg o.d. was effective in significantly lowering blood pressure in this group of mild-to-moderate hypertensive patients in comparison with placebo. The efficacy and the side-effect profile of moxonidine were comparable to those of the first-line antihypertensive agent hydrochlorothiazide. The combination of moxonidine and hydrochlorothiazide in the same dosage as a monotherapy improves efficacy significantly without additive effects on the safety profile. Response rate after monotherapies was calculated with 70.3 and 70.0%, respectively, after combination treatment in 87.8% of all patients in the treatment group. The trial gives support to a recommended dosage regimen of moxonidine 0.4 mg o.d. This profile of moxonidine is highly comparable to a standard first-line antihypertensive drug such as hydrochlorothiazide, without sacrificing tolerance and safety for increased efficacy, in combination with hydrochlorothiazide.

Primary malignant mesenchymoma of bone.

Primary malignant mesenchymoma of bone is a rare neoplasm consisting of two or more unrelated tissue elements other than a fibrosarcomatous component. To our knowledge, only six cases have been reported in the literature. A case of malignant mesenchymoma composed of rhabdomyosarcoma, chondrosarcoma, and osteosarcoma arising within the right acetabulum, resulting in the patient's death 4 months after presentation, is reported, and the literature is reviewed, with a discussion of the similarities to dedifferentiated chondrosarcoma.

Transection of radial digital nerve of the thumb during trigger release.

Iatrogenic laceration of the radial digital nerve of the thumb during trigger release occurred in four patients. Histologic cross sections through the thumb in cadaveric specimens at the level of the metacarpophalangeal crease showed the radial digital nerve to be 2.19 mm beneath the dermis and 1.15 mm directly anterior to the radial sesamoid bone. In this position the nerve is vulnerable to transection when it is trapped between the sesamoid and the knife blade.

Cutaneous manifestations of strongyloidiasis.

Strongyloides stercoralis is a small intestinal nematode that has the ability to multiply within the human host. Because of the potential opportunistic behavior of this parasite, immunocompromised patients may develop fatal disseminated infections. Chronic strongyloidiasis may last decades and give rise to various dermatologic lesions, the most characteristic of which is larva currens, a serpiginous creeping urticarial eruption caused by the intradermal migration of the infective filariform larvae. Rarely recognized is the presence of widespread petechiae and purpura that may develop in patients with disseminated infections. A 64-year-old immunosuppressed man developed fatal extraintestinal S stercoralis infection with extensive purpura associated with massive invasion of the skin by migrating larvae.

Complement and antibody deposition in Brazilian pemphigus foliaceus and correlation of disease activity with circulating antibodies.

Brazilian pemphigus foliaceus is a blistering skin disease endemic to central and southern areas of South America. In this study of skin biopsy specimens from 14 patients we present evidence that complement and immunoglobulins were present by direct immunofluorescence in the epidermal intercellular spaces in all patients. Eight of 14 patients had granular deposits of C3 in the basement membrane zone. By indirect immunofluorescence, serum samples from all 19 patients tested demonstrated the presence of circulating IgG autoantibody. Autoantibodies deposited in the intercellular spaces in titers ranging from 1:10 to more than 1:1280, and the titers drastically decreased during treatment. This is the first study to demonstrate complement deposition in the skin in Brazilian pemphigus foliaceus.

Platelet aggregation and thromboxane release induced by arachidonic acid, collagen, ADP and platelet-activating factor following low dose acetylsalicylic acid in man.

The present study was undertaken in order to characterize the dose-dependent nature of acetylsalicylic acid (ASA) on platelet aggregation and plasma thromboxane B2 (TXB2) release in healthy volunteers. Volunteers received either 25, 50, 100 or 500 mg daily for five consecutive days. At the end of the five day period, all dosages of ASA were capable of completely suppressing TXB2 production and arachidonic acid-induced platelet aggregation. At that time, the second phase of ADP-induced aggregation was also blocked. However, while the inhibition following 500 mg ASA was complete after 24 hours, total inhibition with 100, 50 and 25 mg was attained only after two, three and four days, respectively, indicating the cumulative effect of ASA on platelets. Aggregation induced by collagen was also inhibited dose-dependently- yet slower and at no time complete. ASA had no inhibitory effect on aggregation by platelet-activating factor (PAF). It is concluded that a daily dose of 50 mg ASA would suffice in blocking platelet TXA2 production and aggregation induced by most physiological agents.

Concanavalin A and Lens culinaris agglutinin binding patterns in normal and neoplastic sebaceous epithelium.

Formalin-fixed, paraffin-embedded tissue sections of normal skin, sebaceous hyperplasia, nevus sebaceus, sebaceous adenoma, and sebaceous carcinoma were studied by means of biotinylated and FITC conjugated concanavalin A (Con A) and Lens culinaris agglutinin (LCA). At relatively high concentrations of these lectins, all cutaneous epithelial cells were stained. As the concentration of LCA was lowered, there was a corresponding decrease in the intensity of staining of all epithelial cells. With lowered concentrations of Con A, staining of sebaceous epithelium remained strongly positive, while staining of other epithelia decreased in a manner similar to that seen for LCA. These staining patterns were seen in normal and neoplastic tissues. Both Con A and LCA are known to bind to alpha-D-mannopyranosyl and alpha-D-glucopyranosyl residues of glycoproteins and glycolipids. The difference in staining of sebaceous epithelial cells by Con A and LCA suggests that the binding of these lectins is not determined strictly by the presence of alpha-D-mannopyranosyl or alpha-D-glucopyranosyl residues, but is modified by side-chain substitution on the monosaccharides and/or by the oligosaccharide which contains the particular monosaccharide. Whichever event is operative, a saccharide moiety is present on the surface of mature sebaceous cells which has a strong affinity for Con A.

Mechanism of PAF-induced platelet aggregation in man.

The present study was designed to investigate the mechanisms involved in aggregation induced by platelet-activating factor (PAF) in human platelet-rich plasma (PRP). PAF induced dose-dependent aggregation over the range of 50 nM to 14 microM, with a threshold dose of about 100 nM. BN 52021, a recently described PAF antagonist, completely abolished the effect of PAF at a ten-fold higher concentration. None of the concentrations of PAF used significantly increased TXB2 release. In plasma obtained from volunteers who had taken 500 mg acetylsalicylic acid over five days, no change of PAF-induced aggregation could be observed in comparison to the control state. The lipoxygenase inhibitors nordihydroguaiaretic acid and BW 755 C also failed to significantly modify the PAF-induced platelet response. Pretreatment of PRP with the calcium channel blockers verapamil and nifedipine and the calmodulin antagonist trifluoperazine inhibited platelet aggregation by PAF over the entire range tested. These data indicate that PAF may utilize a specific membrane receptor, which can be blocked by BN 52021. Its aggregatory effect is probably mediated via the calcium-calmodulin system. Moreover, derivatives of arachidonic acid do not appear to be primarily involved in PAF-induced aggregation.

Malignant mixed tumor of the gallbladder: report of two cases and a review of the literature.

Two cases of malignant mixed tumor of the gallbladder are reported. The histology of both revealed malignant mesenchymal elements (chondroid, osteoid, fibrous) admixed with adenocarcinoma. One patients had widespread disease and died three days following diagnosis. The second patient had tumor limited to the gallbladder and is alive with no evidence of disease 31 months following cholecystectomy. Only three other such tumors are reported in the English literature. Analysis of these cases indicates that the behavior and etiology of malignant mixed tumors may be similar to that of carcinomas of the gallbladder.

Comparison of two methods for same-day identification of Enterobacteriaceae.

Two commercial methods, API 20E (as modified for same-day enterobacterial identification) and Micro-ID, were evaluated for ability to provide useful same-day information of 368 clinically isolated Enterobacteriaceae. Organisms included Escherichia coli (54), Shigella (7), Edwardsiella tarda (1), Salmonella enteritidis (10), Citrobacter (30), Klebsiella (55), Enterobacter (68), Hafnia alvei (2), Serratia (33), Proteus (64), Morganella morganii (24), Providencia (18), and Yersinia enterocolitica (2). Methods were those of manufacturers without supplemental tests. API at five hours identified 78.5% of strains to species, 9.5% to genus only, 10.1% as part of a spectrum of identifications (SI), and 1.9% incorrect. Micro-ID at four hours yielded 90.0% correct identification to species and 3.3% to genus only, 4.0% SI, and 2.7% incorrect. API identification of many Serratia, Citrobacter, Providencia strains was to genus only; most incorrect results occurred in Serratia marcescens. Micro-ID identified most organisms to species; incorrect identifications were mainly S. marcescens and Klebsiella pneumoniae. Both systems provided excellent identification of E. coli. Both methods sacrifice a degree of accuracy that varies with the species tested, as compared to overnight systems, but both provide rapid information of potential clinical value.

Comparison of three methods for identification of Enterobacteriaceae.

This study compares the ability of three commercial overnight methods, API 20E, Minitek and Enteric-Tek, to accurately and completely identify 368 clinically isolated Enterobacteriaceae without supplemental tests. Organisms included Escherichia coli (54 strains), Shigella spp. (7), Edwardsiella tarda (1), Salmonella enteritidis (10), Citrobacter spp. (30), Klebsiella spp. (55), Enterobacter spp. (68), Hafnia alvei (2), Serratia spp. (33), Proteus spp. (64), Morganella morganii (24), Providencia spp. (18), and Yersinia enterocolitica (2). Methods were those of the manufactures without supplemental tests. API 20E correctly identified 93.2% of strains to species and 3.3% to genus level only, with 3.0% as part of a spectrum of identifications, and 0.5% incorrect identifications. Minitek yielded 96.0% correct identifications to species and 0.5% to genus level only, with 2.5% spectrum identifications, and 1.0% incorrect identifications. Enteric-Tek correctly identified 97.0% of strains to species level with 3.0% spectrum identifications. API 20E identification of some Serratia and Citrobacter strains was to genus level only. Problem organisms for Minitek included Enterobacter agglomerans and Serratia marcescens. A comparison of these three commercial methods shows that all three have the ability to identify most clinically isolated Enterobacteriaceae without supplemental tests.

Comparison of four methods for identification of gram-negative non-fermenters: organisms less commonly encountered in clinical specimens.

Four commercial kits--Oxi/Ferm (OF), API 20E (AP), Minitek (MT), Flow N/F (NF) were evaluated, without additional tests, for identification of 105 opportunistic Gram-negative non-fermentative rods. Of correctly identified 42% of strains, with 35% as part (but not first) of a spectrum of identifications (SI) and 23% incorrect identification. MT yielded 75% correct identification, with 12% SI and 13% incorrect. AP correctly identified 64% of strains, with 26% SI, 10% incorrect. NF correctly speciated 70% of strains, with 24% SI, 6% incorrect. All 4 methods show deficiencies in identification of these rare but increasingly clinically encountered organisms. Addition of new tests/modification of existing ones would render these systems more capable of identifying this organisms group.

Four methods for identification of gram-negative nonfermenting rods: organisms more commonly encountered in clinical specimens.

Four commercial kits, Oxi/Ferm (OF), API 20E (AP), Minitek (MT; BBL Microbiology Systems), and Flow N/F (NF), were evaluated, without additional tests, for identification of 258 gram-negative nonfermentative rods. OF and MT were read after 48 h of incubation, and AP and NF were read after both 24 and 48 h of incubation, respectively. Overall, OF correctly identified 51% of strains, with 46% as part (but not first) of a spectrum of identifications (SI), and 3% incorrect species identification. MT yielded 85% correct identification, with 15% SI. Of 126 glucose-positive strains, or those with greater than or equal to 3 positive AP reactions after 24 h, 60% were correctly identified, with 40% SI; incubation for an additional 24 h raised the rate of correct identification to 99%, with 1% SI. A total of 132 strains yield less than 3 positive AP reactions after 24 h and were identified after 48 h only; of these, 82% were correctly identified, with 17% SI and 1% incorrect species identification. NF correctly identified 79% of cultures after 24 h, with 21% SI; corresponding figures after an additional 24 h of incubation were 80% and 20%, respectively. All four commercial methods show promise; OF is easiest to inoculate, but requires extra tests for optimal identification. AP reliably identifies the majority of clinically important nonfermenters, with fairly good species identification of saccharolytic strains after 24 h. MT yields reliable identification of most nonfermenters and has the advantage of flexibility. NF is easy to inoculate, yields satisfactory identification rates, and may be read after 24 h of incubation.

Traumatic aneurysms of the ulnar artery.

Aneurysms of the ulnar artery are most common secondary to blunt trauma to the hypothenar eminence. The anatomic relationship between the superficial branch of the ulnar artery and the hook of the hamate exposes this segment of the artery to injury. The clinical, roentgenographic, and pathologic features of two patients, one with an acute traumatic episode and one with chronic trauma are presented. True aneurysms developed in both patients that eventuated in digital ischemia. Thrombosis of the aneurysm and adjacent arterial segment seemed to be related to the onset of the ischemic symptoms. Digital artery embolization can complicate the thrombotic episode. Although surgical intervention may correct the ischemic symptoms, prevention via industrial education seems to be the best form of management.