Widespread variation in molecular interactions and regulatory properties among transcription factor isoforms

Most human Transcription factors (TFs) genes encode multiple protein isoforms differing in DNA binding domains, effector domains, or other protein regions. The global extent to which this results in functional differences between isoforms remains unknown. Here, we systematically compared 693 isoforms of 246 TF genes, assessing DNA binding, protein binding, transcriptional activation, subcellular localization, and condensate formation. Relative to reference isoforms, two-thirds of alternative TF isoforms exhibit differences in one or more molecular activities, which often could not be predicted from sequence. We observed two primary categories of alternative TF isoforms: "rewirers" and "negative regulators", both of which were associated with differentiation and cancer. Our results support a model wherein the relative expression levels of, and interactions involving, TF isoforms add an understudied layer of complexity to gene regulatory networks, demonstrating the importance of isoform-aware characterization of TF functions and providing a rich resource for further studies.

Influenza A subtype H3N2 is associated with an increased risk of hospital dissemination - an observational study over six influenza seasons

BACKGROUND

Previous studies on hospital-acquired influenza (HAI) have not systematically evaluated the possible impact of different influenza subtypes. HAI has historically been associated with high mortality, but clinical consequences may be less severe in a modern hospital setting.

AIMS

To identify and quantify HAI for each season, investigate possible associations with varying influenza subtypes, and to determine HAI-associated mortality.

METHODS

All influenza-PCR-positive adult patients (>18 years old) hospitalized in Skåne County during 2013-2019, were prospectively included in the study. Positive influenza samples were subtyped. Medical records of patients with suspected HAI were examined to confirm a nosocomial origin and to determine 30-day mortality.

RESULTS

Of 4110 hospitalized patients with a positive influenza PCR, 430 (10.5%) were HAI. Influenza A(H3N2) infections were more often HAI (15.1%) than influenza A(H1N1)pdm09, and influenza B (6.3% and 6.8% respectively, P<0.001). The majority of HAI caused by H3N2 were clustered (73.3 %) and were the cause of all 20 hospital outbreaks consisting of ≥4 affected patients. In contrast, the majority of HAI caused by influenza A(H1N1)pdm09 and influenza B were solitary cases (60% and 63.2%, respectively, P<0.001). Mortality associated with HAI was 9.3% and similar between subtypes.

CONCLUSIONS

HAI caused by influenza A(H3N2) was associated with an increased risk of hospital dissemination. Our study is relevant for future seasonal influenza infection control preparedness and shows that subtyping of influenza may help to define relevant infection control measures. Mortality in HAI remains substantial in a modern hospital setting.

The histone acetyltransferase KAT6A is recruited to unmethylated CpG islands via a DNA binding winged helix domain

The lysine acetyltransferase KAT6A (MOZ, MYST3) belongs to the MYST family of chromatin regulators, facilitating histone acetylation. Dysregulation of KAT6A has been implicated in developmental syndromes and the onset of acute myeloid leukemia (AML). Previous work suggests that KAT6A is recruited to its genomic targets by a combinatorial function of histone binding PHD fingers, transcription factors and chromatin binding interaction partners. Here, we demonstrate that a winged helix (WH) domain at the very N-terminus of KAT6A specifically interacts with unmethylated CpG motifs. This DNA binding function leads to the association of KAT6A with unmethylated CpG islands (CGIs) genome-wide. Mutation of the essential amino acids for DNA binding completely abrogates the enrichment of KAT6A at CGIs. In contrast, deletion of a second WH domain or the histone tail binding PHD fingers only subtly influences the binding of KAT6A to CGIs. Overexpression of a KAT6A WH1 mutant has a dominant negative effect on H3K9 histone acetylation, which is comparable to the effects upon overexpression of a KAT6A HAT domain mutant. Taken together, our work revealed a previously unrecognized chromatin recruitment mechanism of KAT6A, offering a new perspective on the role of KAT6A in gene regulation and human diseases.

Confidentiality and adolescents' use of providers for health information and for pelvic examinations

OBJECTIVE

To examine the relationship between adolescents' perception of the confidentiality of care provided by their regular health care provider and their reported use of this provider for private health information and for pelvic examinations.

DESIGN

Anonymous, self-report survey.

SETTING

Thirty-two randomly selected public high schools in Massachusetts.

PARTICIPANTS

Of 2224 students in systematically selected 9th and 12th grade classrooms, 1715 (50% male) had a regular provider and a checkup within the last year.

RESULTS

Of teens surveyed, 76% wanted the ability to obtain confidential health care, but only 45% perceived their regular provider to provide this, and only 28% had discussed it explicitly. Logistic regression analyses revealed strong relationships between confidentiality and all outcomes studied. Among adolescents, the likelihood of having discussed sexually transmitted diseases, pregnancy prevention, and/or facts about sex with their provider was greater among teens who received a confidentiality assurance than that for teens who did not (odds ratio [OR] = 2.7; 95% confidence interval [CI], 2.2-3.4). A similar relationship for teens' likelihood of having discussed substance use with the provider was found (OR = 1.8; 95% CI, 1.4-2.3). Among sexually active females, the likelihood of a recent pelvic examination for those who received a confidentiality assurance was greater than for those who did not (OR = 3.3; 95% CI, 2.1-5.5).

CONCLUSIONS

This study furthers evidence of an important link between teens' perception of confidentiality and use of health care services and information. Because teens' health risks lie largely in potential risks from health-related behaviors, confidentiality in health care may be a critical factor in disclosure and discussion of risky behaviors, and ultimately in appropriate use of health care services. Efforts should be made to increase teens' access to confidential health care sources.

Gastroesophageal reflux in infants with hydrocephalus before and after ventriculo-peritoneal shunt operation

Gastroesophageal reflux (GER) is common in neurologically impaired children, especially those with central nervous system disorders. The cause of GER in these children has not yet been defined, but in animal studies, acute elevation of intracranial pressure (ICP) has been shown to result in a decrease in lower esophageal sphincter pressure. Ten infants with hydrocephalus underwent esophageal pH monitoring prior to and after a ventriculoperitoneal (V-P) shunt operation. A significant degree of reflux was present in 5 patients with hydrocephalus prior to shunt operation and reverted to normal in 2. In the other 3 infants, the degree of reflux decreased as evidenced by fewer abnormal parameters and lower scoring in each of the parameters measured. Our study supports the contention that increased ICP in infants is indeed associated with GER. As 4 of the 5 infants with significant reflux suffered from an Arnold-Chiari malformation, a causal relation between increased ICP due to defects involving the fourth ventricle floor and GER is suggested.

Bacterial cholangitis after surgery for biliary atresia

We retrospectively studied the incidence of bacterial cholangitis in 129 infants operated on because of biliary atresia over 5 years. Forty-six of the 101 children who underwent hepatic portoenterostomy had a total of 105 episodes of cholangitis (range one to eight episodes per child). Most episodes occurred within 3 months of the operation. Factors associated with cholangitis included good or partial restoration of bile flow, abnormal intrahepatic bile ducts or cavities at the porta hepatis, and routine postoperative use of antibiotics. External jejunostomy was not effective in preventing cholangitis. In addition to fever and decreased bile flow, increased erythrocyte sedimentation rate and signs of shock were frequently observed. The responsible organisms, most often gram-negative bacteria, were identified in 79 (75%) episodes by blood or liver cultures. Most were susceptible to trimethoprim-sulfamethoxazole and third-generation cephalosporins during the first episode, but only to cephalosporins during later episodes. The incidence of signs of portal hypertension in children with normal serum bilirubin values at age 5 years was not higher in those who had previously experienced one or more episodes of cholangitis.

Time domain analysis of diaphragmatic electromyogram during fatigue in men

Diaphragmatic fatigue has been correlated with a change in the electromyogram recorded from the diaphragm (EMGdi), which suggests that the electromyogram is a potential clinical tool to detect respiratory muscle fatigue. Changes in the EMGdi have previously been quantified by using the power spectral parameters high-low ratio or mean frequency. In this study, we developed an autoregressive model of the EMG in an attempt to improve the analysis of the EMGdi. This model was tested on recordings of the EMGdi that were obtained from an esophageal electrode in five normal subjects breathing to fatigue through an inspiratory resistor. The data obtained from the autoregressive model were directly compared with data from the high-low ratio and mean frequency techniques. The autoregressive model showed an excellent correlation with mean frequency. Both techniques were superior to the high-low ratio measurement. Because the autoregressive model requires much less computation than mean frequency and can be easily implemented in real time on a minicomputer, we propose this as a preferable approach.

Predictive value of intramural pH and other risk factors for massive bleeding from stress ulceration

We have devised and validated an indirect method for measuring the intramural pH in the stomachs of patients in the intensive care unit and have assessed its value in predicting the occurrence of massive hemorrhage from stress ulceration. The 103 patients, studied on an average of 3.8 +/- 0.6 consecutive days, were assigned to one of five groups: no bleeding, weakly positive guaiac, strongly positive guaiac, massive bleeding from an extragastric site, and massive bleeding from stress ulceration. The pH in gastric juice, arterial blood, and the wall of the stomach, PCO2 and PO2 in gastric juice and arterial blood, and [HCO3-] in arterial blood were recorded, together with history of treatment with antacids, cimetidine, and heparin and the number of risk factors known to be associated with bleeding from stress ulceration. Massive bleeding from stress ulceration occurred in 7 patients, all of whom were receiving antacids. Six of these patients died. A logistic analysis of the data obtained showed that the occurrence of bleeding from stress ulceration was best predicted by consideration of the combination of the number of risk factors and intramural pH (p less than 0.0001). Prediction by these variables was not improved by inclusion of any of the other variables recorded. Bleeding from stress ulceration was only seen in patients whose intramural pH had fallen below the lower limit of normality. The data indicate that intensive care unit patients would be better monitored if the intramural pH were measured, and that the occurrence of massive bleeding from stress ulceration would be better averted by maintaining the intramural pH at normal levels.

Is there a difference among human populations in the rate with which mutation produces electrophoretic variants?

Data are summarized that suggest that tropical-zone/tribal/nonindustrialized populations have higher frequencies of certain types of protein variants than temperate-zone/civilized/industrial populations, and it is demonstrated that these differences are not an artifact produced by the contagious type of sampling used with respect to tribal populations. Evidence is reviewed that suggests that a possible explanation of this difference is higher mutation rates in the tribal populations studied.