Novel Homozygous ADAMTS2 Variants and Associated Disease Phenotypes in Dogs with Dermatosparactic Ehlers-Danlos Syndrome

Tissue fragility, skin hyperextensibility and joint hypermobility are defining characteristics of Ehlers-Danlos syndrome (EDS). Human EDS is subclassified into fourteen types including dermatosparactic EDS, characterized by extreme skin fragility and caused by biallelic ADAMTS2 mutations. We report two novel, ADAMTS2 variants in DNA from EDS-affected dogs. Separate whole-genome sequences from a Pit Bull Terrier and an Alapaha Blue Blood Bulldog each contained a rare, homozygous variant (11:2280117delC, CanFam3.1), predicted to produce a frameshift in the transcript from the first coding ADAMTS2 exon (c.10delC) and a severely truncated protein product, p.(Pro4ArgfsTer175). The clinical features of these dogs and 4 others with the same homozygous deletion included multifocal wounds, atrophic scars, joint hypermobility, narrowed palpebral fissures, skin hyperextensibility, and joint-associated swellings. Due to severe skin fragility, the owners of all 6 dogs elected euthanasia before the dogs reached 13 weeks of age. Cross sections of collagen fibrils in post-mortem dermal tissues from 2 of these dogs showed hieroglyphic-like figures similar to those from cases of severe dermatosparaxis in other species. The whole-genome sequence from an adult Catahoula Leopard Dog contained a homozygous ADAMTS2 missense mutation, [11:2491238G>A; p.(Arg966His)]. This dog exhibited multifocal wounds, atrophic scars, and joint hypermobility, but has survived for at least 9 years. This report expands the spectrum of clinical features of the canine dermatosparactic subtype of EDS and illustrates the potential utility of subclassifying canine EDS by the identity of gene harboring the causal variant.

Two-Generation Oral (Diet) Reproductive Toxicity Study of Resorcinol Bis-Diphenylphosphate (Fyrolflex RDP) in Rats

Fyrolflex resorcinol bis-diphenylphosphate (RDP) was evaluated in a two-generation reproductive study as part of a program to assess the overall toxicology of this flame retardant. RDP was administered to male and female Sprague-Dawley rats in the diet at concentrations of 1000, 10,000 or 20,000 ppm. The control group was given diet alone. Parental (P1) animals were treated for 10 weeks prior to mating, during the 2-week mating period, throughout gestation, and through lactation until sacrifice. The F1 generation (P1 offspring) was treated following a regimen similar to P1. The F2 generation was not treated. No significant difference in Utter survival was observed between the control and treated groups. Body weights were significantly decreased in P1 rats during the 1st week due to an initial flavor aversion of the test substance in the diet. Body weight, weight gains, and food consumption were decreased in the test substance-treated pups (F1) during lactationand after weaning. These changes were also attributed to a flavor aversion. Anogenital distance was similar in the control and high-dose groups, whereas vaginal opening and preputial separation were delayed in the 10,000 and 20,000 ppm groups, and were considered to be secondary to the reduction in F1 body weight. Neither parents nor offspring exhibited any test substance-related clinical signs of toxicity. Vaginal cytology and cyclicity and male reproductive functions (sperm count, motility, and morphology) were unaffected by treatment. Mating performance was similar in the treated groups relative to the control. No treatment-related lesions were noted in the reproductive organs. Increased liver weight and associated hepatic periportal hypertrophy were observed in the RDP-treated animals (P1 and F1). In conclusion, there were no adverse effects on reproductive performance or fertility parameters associated with RDP administration in the diet. Fyrolflex RDP administered for greater than 13 weeks and up to the entire life span (i.e., F1, from conception to euthanasia) resulted in increased liver weights with associated periportal hypertrophy. This change was considered an adaptive process associated with RDP metabolism in the liver.

Influence of ferrous iron incorporation on the structure of hydroxyapatite

Iron is a vital element of cellular function within the body. High concentrations of iron can be found in the kidneys and the circulatory system. In bones and teeth it is present as a trace element. The use of iron-based compounds in combination with hydroxyapatite offers a new alternative for prosthetic devices. This work investigates the synthesis and processing of iron containing apatites as a possible new type of ceramic for biomedical devices. Stoichiometric and calcium deficient iron containing apatites were synthesized by a wet chemical reaction with di-ammonium-hydrogen-phosphate, calcium nitrate and a ferrous iron nitrate solution. A secondary phase of tri-calcium-phosphate (TCP) was observed after heat treatment of iron containing, calcium deficient, hydroxyapatite. The apatite structure was maintained after heat treatment of stoichiometric apatite, synthesized in the presence of iron. Sintering in air produced oxidation of Fe2+ to Fe3+, resulting in the formation of hematite as a secondary phase. The introduction of iron into the synthesis of hydroxyapatite causes: (i) an increase of the a-lattice parameter after synthesis and heat treatment in air; (ii) an increase in the c-lattice parameter after sintering in air.

Two-generation reproduction study and immunotoxicity screen in rats dosed with phenol via the drinking water

This study evaluated the potential reproductive toxicity of phenol in a rat two-generation reproduction study, which included additional study endpoints, such as sperm count and motility, developmental landmarks, histological evaluation of suspect target organs (liver, kidneys, spleen, and thymus), weanling reproductive organ weights, and an immunotoxicity screening plaque assay. Phenol was administered to 30 Sprague-Dawley rats/sex/group in the drinking water at concentrations of 0, 200, 1000, or 5000 ppm. Parental (P1) animals were treated for 10 weeks prior to mating, during mating, gestation, lactation, and until sacrifice. The F1 generation (P1 offspring) was treated using a similar regimen, while the F2 generation was not treated. After mating, 10 P1 males/group were evaluated using standard clinical pathology parameters and an immunotoxicity screening plaque assay. Significant reductions in water and food consumption were observed in the 5000-ppm group in both generations; corollary reductions in body weight/body weight gain were also observed. Mating performance and fertility in both generations were similar to controls, and no adverse effects on vaginal cytology or male reproductive function were observed. Vaginal opening and preputial separation were delayed in the 5000-ppm group, and were considered to be secondary to the reduction in F1 body weight. Litter survival of both generations was reduced in the 5000-ppm group. Absolute uterus and prostate weights were decreased in the F1 generation at all dose levels; however, no underlying pathology was observed and there was no functional deficit in reproductive performance. Therefore, these findings were not considered to be adverse. No evidence of immunotoxicity was noted in the 5000-ppm group. The effects noted at the high concentration were presumed to be associated with flavor aversion to phenol in the drinking water. Based on a comprehensive examination of all parameters, the no-observable-adverse-effect level (NOAEL) for reproductive toxicity of phenol administered in drinking water to rats is 1000 ppm. The corresponding daily intake of phenol for an adult rat at the NOAEL of 1000 ppm is equivalent to about 70 mg/kg/day for males and 93 mg/kg/day for females.

A clinical decision process model for evaluating vancomycin use with modified HICPAC guidelines. Hospital Infection Control Practice Advisory Committee

OBJECTIVE

The objective of this study was to evaluate a clinical decision process model for the appropriateness of vancomycin use, using modified Hospital Infection Control Practice Advisory Committee (HICPAC) guidelines.

DESIGN

All nondialysis vancomycin use was reviewed using the retrospective chart review method. The HICPAC guidelines were modified to distinguish between documented and suspected infections and appropriateness of vancomycin use initially and after 3 days of therapy. Data were collected on both vancomycin-use orders and vancomycin-use days.

SETTING

446-bed health maintenance organization teaching hospital.

RESULTS

758 uses of vancomycin from 1993 through 1995 were evaluated using the modified HICPAC guidelines. Initial use was appropriate in 71% of the cases, with 26% used for documented infections and 74% for suspected infections. Of the 536 orders of initial appropriate use, 176 courses of treatment with vancomycin were discontinued appropriately within 3 days. Ongoing use evaluation after 3 days revealed appropriate use in 45%, inappropriate ongoing use in 25%, and empirical ongoing use in 30% of the cases. There were adequate clinical or laboratory data available in 70% of cases after 3 days to discontinue vancomycin or to reclassify from suspected to documented infections or indications. Vancomycin-use evaluation solely after 3 days would not have disclosed 537 initial inappropriate vancomycin-use days, which were 44% of the total inappropriate use days.

CONCLUSIONS

Comprehensive evaluation of vancomycin use with HICPAC guidelines should include a modification to encompass initial and 3-day reevaluation, because most initial use is for suspected, and not documented, infections. HICPAC guidelines do not address the issues of differentiating suspected from documented infection indications or ongoing empirical use. The clinical decision process model is a framework for documentation and data collection for use evaluation and addresses issues not covered in HICPAC vancomycin guidelines. This model could be used by other medical centers for evaluation of vancomycin or other antibiotics.

Quantitative three-dimensional reconstruction of left ventricular volume with complete borders detected by acoustic quantification underestimates volume

Recently a new acoustic-quantification (AQ) technique has been developed to provide on-line automated border detection with an integrated backscatter analysis. Prior studies have largely correlated AQ areas with volumes without direct comparison of volumes for agreement. By using complete AQ-detected borders as the input to a validated method for three-dimensional echocardiographic (3DE) reconstruction, we can compare an entire cavity volume measured with the aid of AQ against a directly measured volume. This would also explore the possibility of applying AQ to 3DE reconstruction to reduce tracing time and enhance routine applicability. To compare reconstructed volumes with actual values in a stable standard allowing direct volume measurement, the left ventricles of 13 excised animal hearts were studied with a 3DE system that automatically combines two-dimensional (2D) images and their locations. Intersecting 2D views were obtained with conventional scanning and AQ imaging, with gains optimized to permit 3D reconstruction by detecting the most continuous AQ borders for each view, with maximal cavity size. Reconstruction was performed with manually traced central endocardial reflections and AQ-detected borders visually reproduced the left ventricular shapes; the AQ reconstructions, however, were consistently smaller. The reconstructed left ventricular (LV) volumes correlated well with actual values by both manual and AQ techniques (r = 0.93 and 0.88, with standard errors of 2.3 cc and 2.0 cc, p = not significant [NS]). Agreement with actual values was relatively close for the manually traced borders (y = 0.93x + 0.68, mean difference = -0.8 +/-2.2 cc). AQ-derived reconstructions consistently underestimated LV volume by 39 +/- 10% (y = 0.62x-0.09, mean difference = -7.8 +/- 3.0 cc, different from manually traced and actual volumes by analysis of variance [ANOVA], F = 69, p<0.00001). The AQ-detected threshold signal was displaced into the cavity, and volume between walls and false tendons was excluded, leading to underestimation, which increased with increasing cavity volume (r = 0.76). The AQ technique can therefore be applied to 3DE reconstruction, providing volumes that correlate well with directly measured values in a stable in vitro standard, minimizing observer decisions regarding manual border placement after image acquisition. However, when the complete borders needed for 3D reconstruction are used, absolute volumes are underestimated with current algorithms that integrate backscatter and displace the detected threshold into the ventricular cavity.

Association between severity of illness and mortality from nosocomial infection

BACKGROUND

For the years 1987 through 1992, a study was undertaken to analyze nosocomial infection mortality data and to stratify risk according to severity of underlying illness to compare with published data from the Centers for Disease Control and Prevention.

METHODS

Nosocomial infections that contributed to or caused death were identified. In addition, during 1990 through 1992, severity of illness was determined as the subjective estimate of the risk of death or lack of risk of death during the current hospital admission before the onset of the nosocomial infection. These groups were named +SIC and -SIC, respectively.

RESULTS

It was determined that the data from death certificates in cases of known nosocomial infection were not sufficient to determine whether nosocomial infection contributed to or caused death. There was a 24% increase in cases of nosocomial infection contributing to or causing death when a physician reviewed deaths in patients with nosocomial infections who did not have a diagnosis of nosocomial infection listed on the death certificate. The rates for nosocomial infections contributing to or causing death are as follows: nosocomial pneumonia, 20%; and bloodstream infections, 19%. In patients who died and had severity of illness determination, there was a statistically significant difference in the rates of nosocomial infections contributing to or causing death between -SIC and +SIC groups for both nosocomial pneumonia and bloodstream infections. The rates for bloodstream infections were as follows: -SIC, 5%; and +SIC, 21%. For nosocomial pneumonia, the rates were as follows: -SIC, 13%; and +SIC, 23%.

CONCLUSION

In published reports from the Centers for Disease Control and Prevention, a rate of 13% is given for nosocomial pneumonia and bloodstream infections contributing to or causing death; however, there is no stratification for severity of illness in these reports. The presence of life-threatening illness before the onset of nosocomial pneumonia or bloodstream infection accounts for most deaths among our patients. For valid comparisons, mortality outcome data for nosocomial infections should be stratified for risk according to severity of underlying illness.

Continuous alendronate treatment throughout growth, maturation, and aging in the rat results in increases in bone mass and mechanical properties

Alendronate (4-amino-1-hydroxybutylidene bisphosphonate) is a novel amino bisphosphonate that is being developed for the treatment of osteolytic bone disorders such as osteoporosis. As part of a 2-year carcinogenicity study, we investigated the morphologic and biomechanical effects of long-term alendronate (ALN) therapy, given throughout skeletal growth, maturation, and aging, on rat vertebrae and femora. Three treatment groups, receiving either deionized water, low- (1.00 mg/kg), or high-dose (3.75 mg/kg) ALN, were given daily oral treatment for 105 weeks. Results from mechanical tests indicate that ALN therapy (in males) increased the vertebral ultimate compressive load by 96% in the high- and 51% in the low-dose groups when compared with controls. ALN similarly increased the male ultimate femoral bending load by 59% in the high- and 31% in the low-dose groups. Vertebrae and femora from female rats treated with both high- and low-dose ALN also failed at significantly higher loads than controls, but no differences were seen between low- and high-dose groups. Morphologic analysis of both male and female vertebrae revealed a dose-dependent increase in area fraction of bone. Rats receiving high-dose ALN had a greater area fraction of bone than those receiving low doses. Both groups were greater than controls. Thus, the administration of ALN resulted in increased femoral cortical bending load when compared with control animals, as well as increased vertebral ultimate compressive load commensurate with a dose-related preservation of vertebral bone.(ABSTRACT TRUNCATED AT 250 WORDS)

Invasive candidal balanitis due to a condom catheter in a neutropenic patient

A 58-year-old man with acute leukemia had balanitis and penile ulceration due to Candida tropicalis after a condom catheter was used because of urinary incontinence. This case illustrates that condom catheters can be associated with serious complications in neutropenic patients and should be used only when absolutely necessary.

Regulation of calcium-binding protein messenger RNA by 1,25-dihydroxycholecalciferol

1,25-Dihydroxycholecalciferol modulates the synthesis of the intestinal calcium-binding protein. To determine if this effect is due to an increase in calcium-binding protein mRNA activity, we measured total cytoplasmic protein-specific mRNA activity from chick intestine in an in vitro wheat germ translation system. 1,25-Dihydroxycholecalciferol enhances calcium-binding protein specific mRNA activity. The sterol does not induce a general increase in mRNA synthesis since the concentration of only a few proteins increased. Thus 1,25-dihydroxycholecalciferol regulates only a subset of genes and specifically affects a transcriptional process involving calcium-binding protein synthesis.

P pulmonale in status asthmaticus

We studied 129 patients during acute, severe asthmatic attacks. Electrocardiograms showed P pulmonale in 49% of patients who had an arterial carbon dioxide tension (PaCo2) greater than or equal to 45 mm Hg and an arterial pH less than or equal to 7.37, whereas P pulmonale was present in only 2.5% of asthmatics who had a PaCO2 less than or equal to 44 mm Hg and a pH greater than or equal to 7.38 (p less than 0.001). P wave and QRS axes were 79 +/- 8 degrees and 80 +/- 20 degrees, respectively, in the presence of P pulmonale. When P pulmonale disappeared, the P wave and QRS axes shifted significantly to the left (p less than 0.001). Electrocardiographic P pulmonale persisted 12 to 60 hr after correction of hypoxemia, hypercapnia, and acidosis. In 7 patients with P pulmonale and respiratory acidosis, cardiac catheterization demonstrated normal artery pressures (PAPs) measured relative to atmospheric pressure. In 12 of these peak inspiratory pulmonary artery transmural pressures (PATPs) were increased. Since increased right heart transumural pressures could result in chamber distention, these data are consistent with the hypothesis that reversible P pulmonale in status asthmaticus is explainable on the basis of markedly negative tidal pleural pressures and increased right heart transmural pressures.

The nature and significance of hyperamylasemia follwing operation

Total serum amylase activity was found to be significantly elevated postoperatively in 11 (10%) of 110 patients undergoing various surgical procedures. Isoamylase analysis revealed that the rise was chiefly in the pancreatic-type isoamylase in seven of the 11 patients showing postoperative serum amylase elevations; in the other four patients, the elevation occurred principally in the salivary-type isoamylase. These data demonstrate that postoperative hyperamylasemia occurs surprisingly often and that serum amylase activity may rise even when the surgical procedure is extra-abdominal. Moreover, elevation of serum amylase activity after surgery is not necessarily an indication of pancreatitis and may reflect instead a rise in salivary-type isoamylase.