Effects of triple antioxidant therapy on measures of cardiovascular autonomic neuropathy and on myocardial blood flow in type 1 diabetes: a randomised controlled trial.

AIMS/HYPOTHESIS: We evaluated the effects of a combination triple antioxidant therapy on measures of cardiovascular autonomic neuropathy (CAN) and myocardial blood flow (MBF) in patients with type 1 diabetes. METHODS: This was a randomised, parallel, placebo-controlled trial. Participants were allocated to interventions by sequentially numbered, opaque, sealed envelopes provided to the research pharmacist. All participants and examiners were masked to treatment allocation. Participants were evaluated by cardiovascular autonomic reflex testing, positron emission tomography with [(11)C]meta-hydroxyephedrine ([(11)C]HED) and [(13)N]ammonia, and adenosine stress testing. Markers of oxidative stress included 24 h urinary F2-isoprostanes. Diabetic peripheral neuropathy (DPN) was evaluated by symptoms, signs, electrophysiology and intra-epidermal nerve fibre density. Randomised participants included 44 eligible adults with type 1 diabetes and mild-to-moderate CAN, who were aged 46 ± 11 years and had HbA1c 58 ± 5 mmol/mol (7.5 ± 1.0%), with no evidence of ischaemic heart disease. Participants underwent a 24-month intervention, consisting of antioxidant treatment with allopurinol, α-lipoic acid and nicotinamide, or placebo. The main outcome was change in the global [(11)C]HED retention index (RI) at 24 months in participants on the active drug compared with those on placebo. RESULTS: We analysed data from 44 participants (22 per group). After adjusting for age, sex and in-trial HbA1c, the antioxidant regimen was associated with a slight, but significant worsening of the global [(11)C]HED left ventricle RI (-0.010 [95% CI -0.020, -0.001] p = 0.045) compared with placebo. There were no significant differences at follow-up between antioxidant treatment and placebo in the global MBF, coronary flow reserve, or in measures of DPN and markers of oxidative stress. The majority of adverse events were of mild-to-moderate severity and did not differ between groups CONCLUSIONS/INTERPRETATION: In this cohort of type 1 diabetes patients with mild-to-moderate CAN, a combination antioxidant treatment regimen did not prevent progression of CAN, had no beneficial effects on myocardial perfusion or DPN, and may have been detrimental. However, a larger study is necessary to assess the underlying causes of these findings.

Inter-observer variability of prostate delineation on cone beam computerised tomography images.

AIM: To determine the inter-observer variability of defining the prostate gland on cone beam computerised tomography images for the purposes of image-guided radiotherapy. MATERIALS AND METHODS: Five genitourinary oncologists contoured the prostate gland on five cone beam computerised tomography datasets. The variations in prostate boundary delineation and consequent isocentre placement between observers were measured. Variations in volume and centre of mass were calculated. The variation in boundary definition was determined with finite element modelling. RESULTS: The average standard deviation for centre of mass displacements was small, measuring 0.7, 1.8 and 2.8mm in the left-right, anterior-posterior and superior-inferior directions, respectively. The standard deviation for volume determination was 8.93 cm(3) with large variability (3.98-19.00 cm(3)). The mean difference between the computerised tomography-derived volume and the mean cone beam-derived volume was 16% (range 0-23.7%). The mean standard deviations for left-right, anterior-posterior and superior-inferior boundary displacements were, respectively, 1.8, 2.1 and 3.6 mm. The maximum deviation seen was 9.7 mm in the superior direction. CONCLUSION: Expert observers had difficulty agreeing upon the location of the prostate peri-prostatic interface on the images provided. The effect on the centre of mass determination was small, and inter-observer variability for prostate detection on cone beam computerised tomography images is not prohibitive to the use of soft tissue guidance protocols. Potential exists for significant systematic matching errors, and points to the need for rigorous therapist image recognition training and development of guidance protocols before clinical implementation of soft tissue cone beam image guidance.

Absorbance of opaque microstructures in optically diffuse media.

In this study experimental measurements are used to determine that the observed absorbance of opaque microstructures in optically diffuse media correlates with the total surface area rather than the attenuation as calculated in a nonscattering environment. The data suggest that it may be possible to use remote measurements of optical diffuse transmission to quantify surface areas of microcapillaries that are highly absorbing or larger blood vessels that can have high intrinsic attenuation because of hematocrit alone. Results obtained in a transmission geometry are insensitive to the position of the microstructure along the line between source and detector, whereas those collected in a remission geometry are highly sensitive to the depth at which the structure is located. These types of measurement involving microscopic structures embedded in diffuse media have potential application in quantifying blood vessel surface areas that contain contrast agents or other microparticles within tissue.

Characterization of 13 newly isolated strains of anaerobic, cellulolytic, thermophilic bacteria.

Characteristics of 13 newly isolated thermophilic, anaerobic, and cellulolytic strains were compared with previously described strains of Clostridium thermocellum: ATCC 27405 and JW20 (ATCC 31549). Colony morphology, antibiotic sensitivity, fermentation end-products, and cellulose degradation were documented. All 13 strains were sensitive to erythromycin (5 microg/ml) and chloramphenicol (25 microg/ml), and all strains but one were sensitive to kanamycin (20 microg/ml). Polymerase chain reaction (PCR) amplification using primers based on gene sequences from C. thermocellum ATCC 27405 was successful for all 13 strains in the case of the hydrogenase gene and 11 strains in the case of phosphotransacetylase/acetate kinase genes. Ten strains amplified a product of the expected size with primers developed to be specific for C. thermocellum 16SrRNA primers. Two of the 13 strains did not amplify any product with the PCR primers designed for the phosphotransacetylase/acetate kinase and 16SrRNA primers. A MboI-like GATC- recognizing restriction activity was present in all of the five strains examined. The results of this study have several positive implications with respect to future development of a transformation system for cellulolytic thermophiles.

An investigation into the practice of concurrent chronic ambulatory peritoneal dialysis catheter insertion and arteriovenous fistula formation in patients needing dialysis.

To review the practice of concurrent chronic ambulatory peritoneal dialysis catheter insertion and arteriovenous fistula formation in patients needing dialysis, we retrospectively assessed the results of arteriovenous fistula procedures, the risk factors for fistula failure, and the selection strategy used to choose which patients with end-stage renal disease would be given dialysis. We analysed the medical records of 136 patients who had first-time arteriovenous fistulae created between 1 July 1986 and 1 May 1994 at a public hospital in Sydney, Australia. As many as 36% of fistulae were never used (24.5% due to primary failure) and 30.1% of the fistulae used had to be abandoned for various reasons. In addition, 22.8% of patients experienced complications, the most common being thrombosis and stenosis. None of the factors associated with fistula formation were significant in terms of fistula patency rates, but smokers and female patients had inferior fistula patency rates. Whereas the overall results were satisfactory, the practice of concurrent chronic ambulatory peritoneal dialysis catheter insertion and arteriovenous fistula formation to give vascular access for dialysis is questionable.

Protease nexin 1 is expressed in the human placenta.

Protease nexin 1 (PN1), a serine protease inhibitor that inactivates thrombin, urokinase, and plasmin, is produced abundantly in cultures of human fibroblasts and rat and human glioma cells. The major sites of PN1 synthesis in vivo and the specific physiological function(s) of this serpin are unknown. Using Northern blot analysis and a full-length PN1 cDNA probe we demonstrated the presence of PN1 mRNA in human term placentas. In situ hybridization of placental tissue with a PN1 riboprobe showed that PN1 mRNA is present throughout the placenta and is also abundant in the placental membranes. Immunohistochemical analysis with an anti-PN1 antibody showed co-localization of PN1 and its mRNA within the placenta.

Polymorphic assembly of subtilisin-cleaved tubulin.

Limited proteolysis of tubulin with subtilisin results in cleavage of both the alpha and beta subunits, releasing small peptides from the C-terminal ends. At 37 degrees C the digested tubulin assembles into polymorphic structures: microtubules with attached ribbons in the presence of GTP, rings in the presence of GDP, and protofilament spirals in the presence of vinblastine. Undigested tubulin does not assemble under these conditions. Rings and Vinca-induced spiral structures are assembled from undigested tubulin only when microtubule-associated proteins, high Mg2+ concentrations, or polycations are present. Thus, cleavage with subtilisin affects assembly in a manner similar to the addition of these agents. It appears that binding of positively charged substances may act by neutralizing the charge on the highly acidic C-terminal regions of the alpha- and beta-subunits, while cleavage with subtilisin produces the same effect by removing these peptides. Undigested and subtilisin-digested tubulin form sheets of protofilaments in the presence of Zn2+, which indicates that the binding sites for the 2-3 Zn2+ ions necessary to induce sheet formation do not reside in the C-terminal regions of the monomers.

Resolution of acromegaly, amenorrhea-galactorrhea syndrome, and hypergastrinemia after resection of jejunal carcinoid.

A young woman presented with acromegaly and amenorrhea-galactorrhea with hypersomatotropinemia and hyperprolactinemia. In addition, she had hypergastrinemia with abnormal secretory dynamics and evidence of a large pituitary tumor with suprasellar extension and erosion of the floor of the sella turcica. Evaluation of secretory diarrhea revealed a large abdominal tumor, which on removal was found to be a carcinoid of the jejunum. Postoperatively, the acromegaly, amenorrhea-galactorrhea, and hypergastrinemia resolved, and the pituitary returned to normal size, with regrowth of the sella floor. The carcinoid tumor was shown by immunoperoxidase staining to contain GH-releasing hormone.

Pathogenicity of retroviruses containing either the normal human c-Ha-ras1 gene or its mutated form derived from the bladder carcinoma EJ/T24 cell line.

Cellular ras oncogenes transduced by retroviruses carry mutations in amino acids 12, 59 and 122. Similar mutations have been observed in ras oncogenes activated during induction of neoplasia in both humans and experimental animals. The unmutated normal rat or human c-Ha-ras-1 genes have the ability to transform NIH 3T3 cells in culture when activated by a RNA synthesis promoter. These findings raise the question of whether the mutations are necessary for the ras oncogenes to induce the neoplastic phenotype in vivo. To address this question, we inserted the normal human c-Ha-ras-1 or its mutated counterpart EJ/T24 bladder carcinoma oncogene independently into a retrovirus vector derived from the M1 strain of Moloney murine sarcoma virus (MoMuSV). Both recombinant clones induced foci of transformed cells in an NIH 3T3 cell transfection assay. Infectious virus particles were rescued from cloned transformants carrying a single copy of the integrated provirus using the nonpathogenic amphotrophic wild mouse leukemia virus (WMLV) as helper. The pseudotypes rescued from the EJ/T24-containing transformants had higher titers than the normal c-Ha-ras-1 pseudotypes as determined by a focus assay and gave rise to larger and earlier detected foci upon infection of NIH 3T3 cells. The two pseudotypes were tested for in vivo pathogenicity by inoculation into newborn NFS mice and were compared to the pseudotype WMLV/Harvey murine sarcoma virus (HaMuSV) (positive control) and WMLV (negative control). While the WMLV/EJ/T24 and the WMLV/HaMuSV pseudotypes induced erythroleukemias and sarcomas with a latency period of 6-9 weeks, the WMLV/c-Ha-ras-1 pseudotype induced only mild splenomegaly. As expected the WMLV negative control induced no pathology. Tumor-bearing animals that were not euthanized at 6-9 weeks died within 2-3 months following virus inoculation.

Trypanosoma lucknowi, a new species of trypanosome from Macaca mulatta with observations on its fine structure.

Trypanosoma lucknowi n. sp. was isolated in culture from one of 126 Macaca mulatta originating from the vicinity of Lucknow, Uttar Pradesh, India. Trypanosoma lucknowi is distinctive because of the large number of epimastigotes and trypomastigotes which, in culture, exhibit no movement or only a slight bending of the flagellar end. This limited motility coincides with a free flagellum which is either completely absent or rudimentary. The microorganism is cloned readily, and the description is based upon such cultures. Trypanosoma lucknowi shows pronounced differences from other trypanosomes of South Asian macaques and from "aflagellar" African trypanosomes. The ultrastructural demonstration of a cytostome and contractile vacuole suggests ultimate grouping with stercorarian trypanosomes. A 3-D reconstruction of the flagellar pocket/cytostome region is included.

Use of computed tomography in diagnosing the cause of primary aldosteronism.

We performed computed tomography (CT) in 22 consecutive patients with primary aldosteronism to evaluate the usefulness of this technique in diagnosing and locating aldosterone-producing adenomas. Sixteen patients had severe hypokalemia, hyperaldosteronism, and elevated plasma levels of 18-hydroxycorticosterone suggestive of an adenoma. In 12 of these 16, a unilateral adrenal mass was demonstrated clearly, and in all 11 who had surgery in adenoma was confirmed. In the other four patients in this group, one adrenal gland was normal and the other was either not seen adequately or had minor abnormalities that could not be definitely classified; an adenoma was found in the poorly visualized gland in each of the two patients who had surgery. The remaining six patients, who had milder biochemical abnormalities suggestive of idiopathic hyperaldosteronism, had bilateral adrenal enlargement or normal-appearing glands on scan and were not surgically explored. We conclude that CT scans, together with appropriate biochemical measurements, are useful in diagnosing and locating aldosterone-producing adenomas.

Virulence of three strains of Staphylococcus aureus isolated from clinically infected bovine mammary glands.

Factors in the ability of three strains of Staphylococcus aureus to cause bovine mastitis were studied. Each strain was evaluated fro growth rate, clump size, and resistance to phagocytosis and intracellular kill by polymorphonuclear leukocytes isolated from milk of nine cows. Variation among cows in the ability of polymorphonuclear leukocytes to phagocytose and of skim milk to support phagocytosis was assessed. Virulent strains of Staphylococcus aureus had a smaller clump size (1.5 colony forming units [CFU]/clump) than the less virulent strain (2.6 CFU/clump) after 180 min of growth in skim milk samples. When the skim milk samples were sonicated to disperse the staphylococci, population density of strains of Staphylococcus aureus did not differ. Phagocytosis and total number of staphylococci killed by polymorphonuclear leukocytes were depressed for virulent strains. Ability of polymorphonuclear leukocytes isolated from individual cows to phagocytose each strain of Staphylococcus aureus varied. The correlation with treated cases of clinical mastitis per lactation was -.54. The ability of skim milk to support phagocytosis by polymorphonuclear leukocytes also differed among cows. The correlation with treated cases of clinical mastitis per lactation was -.51.

Computed tomography of experimental acute renal ischemia.

The potential role of computed tomography (CT) in the detection of acute renal ischemia was assessed in nine mongrel dogs. Ischemia was produced by inflation of a balloon catheter in the main renal artery, with scans performed before, during, and after a 60-minute period of ischemia. A small but consistent increase in the attenuation value of ischemic renal parenchyma was observed. When intravenous contrast material was given, the ischemic kidney was markedly less enhanced than the contralateral, nonischemic kidney. By using the contralateral kidney for comparison, the ischemic kidney could be identified with or without the use of a contrast agent. Although calculations of mean pixel values were necessary when a contrast agent was not injected, the abnormal kidney could be easily recognized from the CT images themselves when intravenous contrast material was given. Because of the consistency with which the abnormalities were observed, we recommend a clinical trial of CT in suspected acute renal ischemia.

Computed tomography in the diagnosis of adrenal disease.

A series of 63 patients with suspected adrenal disease was evaluated by computed tomography (CT). In 15 additional patients CT diagnosed unsuspected adrenal disease. The CT results were correlated with surgical, postmortem, or compelling clinical data. In those patients with adequate visualization of both adrenals, CT correctly identified all adrenal masses subsequently proven at surgery or postmortem examination. CT accurately predicted the presence or absence of a unilateral adrenal neoplasm in patients with Cushing's syndrome and primary aldosteronism. Unsuspected primary or metastatic neoplasms of the adrenals were occasionally detected in patients scanned for other reasons. CT is a safe and accurate method of evaluating patients with suspected adrenal disease.

Hilar and mediastinal adenopathy caused by bacterial abscess of the lung.

Enlargement of hilar and mediastinal lymph nodes commonly accompanies a lung abcess. Of 27 patients with lung abscesses, 14 had hilar or mediastinal adenopathy or both. The problem resolved promptly with clearing of the abcesses and was absent on clinical and radiographic follow-up.