Ectodermal dysplasias: Classification and organization by phenotype,genotype and molecular pathway

An international advisory group met at the National Institutes of Health in Bethesda, Maryland in 2017, to discuss a new classification system for the ectodermal dysplasias (EDs) that would integrate both clinical and molecular information. We propose the following, a working definition of the EDs building on previous classification systems and incorporating current approaches to diagnosis: EDs are genetic conditions affecting the development and/or homeostasis of two or more ectodermal derivatives, including hair, teeth, nails, and certain glands. Genetic variations in genes known to be associated with EDs that affect only one derivative of the ectoderm (attenuated phenotype) will be grouped as non‐syndromic traits of the causative gene (e.g., non‐syndromic hypodontia or missing teeth associated with pathogenic variants of EDA “ectodysplasin”). Information for categorization and cataloging includes the phenotypic features, Online Mendelian Inheritance in Man number, mode of inheritance, genetic alteration, major developmental pathways involved (e.g., EDA, WNT “wingless‐type,” TP63 “tumor protein p63”) or the components of complex molecular structures (e.g., connexins, keratins, cadherins).     

Recruitment and baseline epidemiologic profile of participants in the first phase 3 HIV vaccine efficacy trial

OBJECTIVE: To describe recruitment and baseline epidemiologic characteristics of volunteers in the first phase 3 placebo-controlled trial of a recombinant gp120 HIV vaccine (AIDSVAX B/B). METHODS: Volunteers were gay/bisexual men or women at risk for sexually transmitted HIV infection. Recruitment strategies, demographics, and risk factors were assessed. HIV status was determined by standard HIV-1 antibody assays. Seronegative/viremic HIV infection at enrollment was determined using the HIV-1 nucleic acid test. RESULTS: From June 1998 through October 1999, 5417 of 7185 volunteers screened were enrolled at 61 sites in the United States, Canada, and The Netherlands. Successful recruitment methods included distribution of study information at gay venues, advertising and media coverage, and referrals from volunteers. Most volunteers were altruistically motivated, men (98%), young (median, 36 years), white (83%), well educated (61% college education or more), and at high risk for HIV during the 6 months before enrollment. At baseline, 14 were HIV infected (12 were seronegative but viremic; 2 were seropositive and viremic). CONCLUSION: Men and women at high risk for sexually transmitted HIV infection were successfully recruited for the first phase 3 HIV vaccine efficacy trial. Knowledge of recruitment and baseline epidemiologic characteristics of participants in this trial will provide valuable guidance for designing and conducting future trials.     

Leukotrienes do not contribute to the pathogenesis of indomethacin-induced ulceration of the gastric antrum in the re-fed rat

The potential involvement of leukotrienes in the pathogenesis of indomethacin-induced ulceration of the rat gastric antrum has been studied. Pretreatment with the leukotriene biosynthesis inhibitor, MK886 (30 mg/kg p.o.), inhibited the increases in blood and antral leukotriene B₄ releaseex vivo associated with the evolution of antral ulceration. Despite this, however, there was no significant reduction in either the area of antral ulceration, or in the associated blood neutrophilia and neutrophil infiltration into the gastric antrum. Similarly, pretreatment with the leukotriene B₄ antagonist, SC41930 (50 mg/kg p.o.) or the peptidyl leukotriene antagonist ICI198,615 (50 mg/kg p.o.) did not inhibit the area of antral ulceration induced by indomethacin.Thus, in contrast to published reports studying fundic ulceration, our results suggest that leukotrienes do not play a major role either in the pathogenesis of indomethacin-induced ulceration of the rat gastric antrum or neutrophil infiltration into the damaged antrum.     

Occurrence of cancer in Asians and non-Asians.

Cancer registration data for a defined geographical area, covering a seven year period, were modified to include the variable "Asian ethnic origin." The data were then used to test the hypothesis that a difference would be found between Asians and non-Asians in the pattern of cancer by site. Whereas the incidence of cancer of all sites appeared to be significantly lower in Asians (p less than 0.05), after taking account of this, and adjusting for the very different age distributions of the two populations, a highly significant difference (p less than 0.0005) was found between the two groups in the distribution of cancer between sites. Although, given the size and young age structure of the Asian population, absolute numbers of cases were small, a significant excess of Asian cases (compared with the expected) occurred for cancer of the tongue, oral cavity, pharynx, and oesophagus. For most sites there were fewer Asian cases than would be expected, particularly so for the stomach, testis, and skin. The results indicate the need for formal epidemiological study to test specific aetiological hypotheses which may account for these apparent differences.     

Low-Dose ATG/GCSF in Established Type 1 Diabetes: A Five-Year Follow-up Report

Previously, we demonstrated low-dose antithymocyte globulin (ATG) and granulocyte colony-stimulating factor (GCSF) immunotherapy preserved C-peptide for 2 years in a pilot study of patients with established type 1 diabetes (n = 25). Here, we evaluated the long-term outcomes of ATG/GCSF in study participants with 5 years of available follow-up data (n = 15). The primary end point was area under the curve (AUC) C-peptide during a 2-h mixed-meal tolerance test. After 5 years, there were no statistically significant differences in AUC C-peptide when comparing those who received ATG/GCSF versus placebo (P = 0.41). A modeling framework based on mean trajectories in C-peptide AUC over 5 years, accounting for differing trends between groups, was applied to recategorize responders (n = 9) and nonresponders (n = 7). ATG/GCSF reponders demonstrated nearly unchanged HbA_1c over 5 years (mean [95% CI] adjusted change 0.29% [–0.69%, 1.27%]), but the study was not powered for comparisons against nonresponders 1.75% (–0.57%, 4.06%) or placebo recipients 1.44% (0.21%, 2.66%). These data underscore the importance of long-term follow-up in previous and ongoing phase 2 trials of low-dose ATG in recent-onset type 1 diabetes.     

Repeated Independent Exposures to Domoic Acid Do Not Enhance Symptomatic Toxicity in Outbred or Seizure-Sensitive Inbred Mice

Domoic acid (DA) is an environmental neurotoxin to humans. Thiswork examines whether repeated exposure to subsymptomatic orsymptomatic nonlethal doses of domoic acid leads to enhancedsymptomatic toxicity in ICR outbred and DBA inbred strains oflaboratory mice. A multiple independent exposure paradigm wasdesigned in which doses were administered intraperito neallyevery other day for 7 days to achieve four separate exposuresto domoic acid. We first examined the effect of repeated exposureon serum clearance of domoic acid. Serum domoic acid levelsdid not differ following a single or repeated exposure. We nextexamined the effect of repeated exposure on symptomatic toxicity.The mean toxicity scores did not show a significant differencebetween single and repeated exposures of either subsymptomatic(0.5 mg/ kg) or symptomatic sublethal (2.0 mg/kg) doses of domoicacid. We then examined the effects of repeated domoic acid exposureon a second strain of mouse. DBA mice were chosen based upontheir sensitivity to kainic acid-induced seizures; however,the ICR mice were more sensitive to low-dose domoic acid toxicity,particularly in terms of onset and duration of stereotypic scratchingbehavior. Our results indicate that both strains of mice havecomparable concentration-dependent toxic responses to domoicacid; however, differences exist in the magnitude of the responseand in specific symptoms. The mean toxicity scores did not showa significant difference when a single exposure (1.0 and 2.0mg/kg domoic acid) and repeated exposure of the same dose werecom pared in the DBA mice. This study provides no evidence thatshort-term repeated exposure to domoic acid in laboratory micealters domoic acid clearance from the serum, or leads to a moresensitive or a greater neurotoxic response.     

National human exposure assessment survey (NHEXAS): exploratory survey of exposure among population subgroups in EPA Region V

The National Human Exposure Assessment Survey (NHEXAS) provides a rich database of exposure and environmental measurements for persons living in EPA Region V (Great Lakes). Demographics (e.g., gender, minority status, age, income, and year home built) between U.S. Census data and the overall Region V sample were compared and showed good agreement. This representative sample was used to conduct an exploratory investigation of selected subpopulations that might exhibit higher exposures, on average, to volatile organic chemicals (VOCs) such as benzene, chloroform, etc.; inspirable particles; and metals (e.g., lead, arsenic, etc.) than the general population in Region V. Means and medians were the metrics of comparison. Personal air exposures for p-dichlorobenzene were significantly higher in adults (> 21 years old) than in children (1-14 years old) (median: below detection limit vs. 0.87 microgram/m3, p = 0.0005), while a trend toward higher levels of arsenic exposure in children than adults was observed (median: 1.13 vs. 0.8 ng/m3, p = 0.083). A trend towards higher personal air exposure to lead for minorities vs. nonminorities was evident (median: 26 vs. 12 ng/m3, p = 0.066), but personal exposure to 1,1,1-trichloroethane tended to be higher in nonminorities (mean: 22 vs. 3.7 micrograms/m3, p = 0.081). Dietary exposure to arsenic from solid foods was significantly higher in adults than children (mean: 21 vs. 7.1 micrograms/kg, p = 0.0001; median: 10 vs. 5.6 micrograms/kg, p = < 0.001), and for cadmium it was higher for nonminorities than minorities (median: 18 vs. 15 micrograms/kg, p = 0.023). In contrast, the dietary intake for arsenic, which is based on body weight, was significantly higher in children than adults (mean: 1.72 vs 1.38 micrograms/kg-1 day-1, p = < 0.0001; median 1.02 vs. 0.83, p = < 0.0001). Dietary exposure to chromium in beverages tended to be higher in minorities than nonminorities (median: 16 vs. 13 micrograms/kg, p = 0.017). Lead levels in surface dust wipes tended to increase with the age of the home (mean: 128 micrograms/g in homes built since 1980 to 1075 micrograms/g in homes built before 1940; median: 93 to 236 micrograms/g, respectively). These findings were consistent with the observation that for persons living in older homes personal air exposures to lead are elevated compared to persons living in recently built homes (median: 12 ng/m3 in homes built since 1980, vs. 24 ng/m3 in homes built before 1940, p = 0.043).