Transfer function approach to understanding periodic forcing of signal transduction networks.

Signal transduction networks are responsible for transferring biochemical signals from the extracellular to the intracellular environment. Understanding the dynamics of these networks helps understand their biological processes. Signals are often delivered in pulses and oscillations. Therefore, understanding the dynamics of these networks under pulsatile and periodic stimuli is useful. One tool to do this is the transfer function. This tutorial outlines the basic theory behind the transfer function approach and walks through some examples of simple signal transduction networks.

Using online tools at the Bovine Genome Database to manually annotate genes in the new reference genome.

With the availability of a new highly contiguous Bos taurus reference genome assembly (ARS-UCD1.2), it is the opportune time to upgrade the bovine gene set by seeking input from researchers. Furthermore, advances in graphical genome annotation tools now make it possible for researchers to leverage sequence data generated with the latest technologies to collaboratively curate genes. For many years the Bovine Genome Database (BGD) has provided tools such as the Apollo genome annotation editor to support manual bovine gene curation. The goal of this paper is to explain the reasoning behind the decisions made in the manual gene curation process while providing examples using the existing BGD tools. We will describe the sources of gene annotation evidence provided at the BGD, including RNA-seq and Iso-Seq data. We will also explain how to interpret various data visualizations when curating gene models, and will demonstrate the value of manual gene annotation. The process described here can be applied to manual gene curation for other species with similar tools. With a better understanding of manual gene annotation, researchers will be encouraged to edit gene models and contribute to the enhancement of livestock gene sets.

Seroprevalence of Toxocara at Tra Vinh University Hospital in Vietnam.

OBJECTIVE: The study aims to assess the seroprevalence of Toxocariasis and its associated risk factors among individuals attending the outpatient department at Tra Vinh University Hospital, Vietnam, in 2022. SUBJECTS AND METHODS: A cross-sectional survey was conducted among outpatients of Tra Vinh University Hospital. Toxocariasis diagnosis was based on the Enzyme-Linked Immunosorbent Assay (ELISA) performed at the hospital's laboratory department. We assessed the seroprevalence of Toxocariasis and evaluated associated risk factors, including demographics and certain behaviors. RESULTS: Of the 249 participants surveyed, 165 tested positive for Toxocariasis, yielding a seroprevalence of 66.3% (95% CI: 60.4-72.1). Multivariate analysis revealed that age groups up to 30 and 30-60 years had higher odds of Toxocariasis infection, with adjusted odds ratios (aOR) of 2.52 (95% CI: 1.04-6.11) and 3.21 (95% CI: 1.44-7.15) respectively. Additionally, individuals residing in rural areas and those in contact with dogs or cats had increased risks, with aORs of 2.21 (95% CI: 1.21-4.01) and 2.04 (95% CI: 1.10-3.79), respectively. Notably, hand washing before eating emerged as a protective factor against Toxocariasis, presenting an aOR of 0.38 (95% CI: 0.19-0.76). CONCLUSIONS: Our findings underscore a significant seroprevalence (66.3%) of Toxocara spp. among outpatients at Tra Vinh University Hospital. Proactive measures, including hand hygiene before meals and after pet interactions, are advocated. There is a pronounced need for community-level epidemiological surveillance for human Toxocariasis.

[Diagnosis of oesophageal reflux by PH, impedance, and bilirubin measurement: recommendations of the German Society of Neurogastroenterology and of the working group for neurogastroenterology of the German Society for Digestive and Metabolic Diseases]. / Ösophageale Refluxdiagnostik - pH-Metrie, Impedanzmessung, Bilirubin-Messung: Empfehlungen der Deutschen Gesellschaft für Neurogastroenterologie und Motilität und der Arbeitsgruppe Neurogastroenterologie der Deutschen Gesellschaft für Verdauungs- und Stoffwechselkrankheiten.

The current recommendations on indications, technical performance, and interpretation of diagnostic techniques for oesophageal reflux update the German recommandations about 24 hour pH measurement of 2003. The recommendations encompass conventional pH measurement, wireless pH measurement, pH and impedance measurements, and bilirubin measurement (duodenogastro-oesophageal reflux).

Influence of Irradiation on the Biology of the Brown Marmorated Stink Bug (Hemiptera: Pentatomidae).

Fifth-instar brown marmorated stink bug (Halyomorpha halys Stål) nymphs were treated by gamma-radiation 60Co at different doses of 8-64 Gy to investigate their irradiation biology and potential for the sterile insect technique (SIT). At adult emergence, males were mated with non-irradiated virgin females to assess the longevity of both sexes, female fecundity, and egg sterility. Biological parameters of their F1 progeny were investigated to determine whether negative effects from parental exposure to radiation were inherited. Results showed that irradiation significantly reduced the lifespan of male insects at doses above 20 Gy. Irradiated males did not affect the longevity and fecundity of their female partners, nor of their resulting adult progenies, but it did reduce the developmental duration of nymphs as well as weight gain of male F1 offspring. Egg hatch was significantly reduced at all tested doses and reached complete sterility at 64 Gy. Low hatch of eggs produced by F1 or F1 crossed adults indicated that negative effects from radiation were inherited by the subsequent generation. But F1 male offspring were not less fertile than their irradiated male parent, unlike what was observed in Lepidoptera. The results support the potential for the use of SIT for H. halys management by irradiating the fifth-instar male nymphs at doses from 16 Gy to 64 Gy.

Using fluorescence lifetime dequenching to estimate the average quinary stoichiometry of proteins in living cells.

Biological proteins are understood in terms of five structural levels-primary, secondary, tertiary, quaternary and quinary. The quinary structure is defined as the set of macromolecular interactions that are transient in vivo. This includes non-covalent protein-protein interactions occurring within the crowded intracellular environment. For much of twentieth century science, the canonical approach to studying biological proteins involved test tube environments. These uncrowded in vitro studies inadvertently failed to replicate and observe the quinary structures present within the original cells. Consequently, contemporary literature surrounding the fifth level of protein organisation is lacking. In particular, there is a lack of literature on the size of transient clusters within living cells. In an attempt to reconcile this gap in knowledge, we propose a quantitative method for estimating the average quinary stoichiometry in living cells. The method is based on lifetime self-quenching of fluorescently-labelled proteins in living cells. Close approach of two or more proteins in a quinary complex will result in self-quenching of the fluorescence lifetime from the fluorescent labels. Our method utilises the random mixing of proteins during cell division to mix fluorescently labelled with unlabelled proteins. Such mixing reduces the probability of adjacency between labelled proteins and, hence, decreases the probability of fluorescence lifetime quenching from labels. By monitoring fluorescence lifetime dequenching during multiple cell divisions, we can determine the average quinary structure in living proliferating cells. We demonstrate this method with a case study on cultured HeLa cells. The average quinary stoichiometry was found to be between five and six. That is, at any given point in time, there are five or six weakly interacting partners in the immediate neighbourhood of any given protein.

Characterization of PTEN mutations in brain cancer reveals that pten mono-ubiquitination promotes protein stability and nuclear localization.

PTEN is a PIP3 phosphatase that antagonizes oncogenic PI3-kinase signalling. Due to its critical role in suppressing the potent signalling pathway, it is one of the most mutated tumour suppressors, especially in brain tumours. It is generally thought that PTEN deficiencies predominantly result from either loss of expression or enzymatic activity. By analysing PTEN in malignant glioblastoma primary cells derived from 16 of our patients, we report mutations that block localization of PTEN at the plasma membrane and nucleus without affecting lipid phosphatase activity. Cellular and biochemical analyses as well as structural modelling revealed that two mutations disrupt intramolecular interaction of PTEN and open its conformation, enhancing polyubiquitination of PTEN and decreasing protein stability. Moreover, promoting mono-ubiquitination increases protein stability and nuclear localization of mutant PTEN. Thus, our findings provide a molecular mechanism for cancer-associated PTEN defects and may lead to a brain cancer treatment that targets PTEN mono-ubiquitination.

Molecular cytogenetic studies towards the full karyotype analysis of human blastocysts and cytotrophoblasts.

Numerical chromosome aberrations in gametes typically lead to failed fertilization, spontaneous abortion or a chromosomally abnormal fetus. By means of preimplantation genetic diagnosis (PGD), we now can screen human embryos in vitro for aneuploidy before transferring the embryos to the uterus. PGD allows us to select unaffected embryos for transfer and increases the implantation rate in in vitro fertilization programs. Molecular cytogenetic analyses using multi-color fluorescence in situ hybridization (FISH) of blastomeres have become the major tool for preimplantation genetic screening of aneuploidy. However, current FISH technology can test for only a small number of chromosome abnormalities and hitherto failed to increase the pregnancy rates as expected. We are in the process of developing multi-color FISH-based technologies to score all 24 chromosomes in single cells within a three-day time limit, which we believe is vital to the clinical setting. Also, human placental cytotrophoblasts (CTBs) at the fetal-maternal interface acquire aneuploidies as they differentiate to an invasive phenotype. About 20-50% of invasive CTB cells from uncomplicated pregnancies were found to be aneuploid, suggesting that the acquisition of aneuploidy is an important component of normal placentation, perhaps limiting the proliferative and invasive potential of CTBs. Since most invasive CTBs are interphase cells and possess extreme heterogeneity, we applied multi-color FISH and repeated hybridizations to investigate the feasibility of a full karyotype analysis of individual CTBs. In summary, this study demonstrates the strength of Spectral Imaging analysis and repeated hybridizations, which provides a basis for full karyotype analysis of single interphase cells.

Relationship between bolus transit and LES-relaxation studied with concurrent impedance and manometry.

BACKGROUND/AIMS: Neuromuscular mechanisms regulating esophageal bolus transport are well studied. However, detailed data about the relationship between bolus transit and lower esophageal sphincter (LES)-relaxation during conventional motility testing are still lacking. METHODOLOGY: We performed systematic studies in 25 normal subjects, employing a catheter that integrates the two techniques impedancometry and manometry in a single instrument for simultaneous recording and analysis of the relationship between bolus transit and LES relaxation after swallowing saline or yogurt. RESULTS: 195 swallows were analyzed. LES relaxation occurred frequently later than UES relaxation. The mean latency between bolus entry into the esophagus and LES relaxation was 3.6 +0.2 sec. Two types of swallow-induced LES relaxation were observed: (a) LES relaxation preceding bolus transit (46 cases or 24%) and (b) LES relaxation occurring during bolus transit (149 cases or 76%). In the later case, during 114 (76%) cases of this deglutition, the position of the bolus was very close to the LES. CONCLUSIONS: During deglutition, LES relaxation seems to be modulated by bolus transit and occurs predominantly upon arrival of the bolus in the distal esophagus.

A new class of cancer-associated PTEN mutations defined by membrane translocation defects.

Phosphatase and tensin homolog (PTEN), which negatively regulates tumorigenic phosphatidylinositol (3,4,5)-trisphosphate (PIP3) signaling, is a commonly mutated tumor suppressor. The majority of cancer-associated PTEN mutations block its essential PIP3 phosphatase activity. However, there is a group of clinically identified PTEN mutations that maintain enzymatic activity, and it is unknown how these mutations contribute to tumor pathogenesis. Here, we show that these enzymatically competent PTEN mutants fail to translocate to the plasma membrane where PTEN converts PIP3 to PI(4,5)P2. Artificial membrane tethering of the PTEN mutants effectively restores tumor suppressor activity and represses excess PIP3 signaling in cells. Thus, our findings reveal a novel mechanism of tumorigenic PTEN deficiency.

Spectrum of cell-cycle kinetics of alkylating agent adolezesin in gynecological cancer cell lines: correlation with drug-induced cytotoxicity.

Adolezesin is an analog of CC-1065. These compounds are among the most potent alkylating agents known to date. Currently Adolezesin is undergoing phase I clinical trials at several cancer centers in the USA. While the cytotoxic effects of Adolezesin have been addressed elsewhere, its effects on cell-cycle kinetics have not been reported. Flow cytometry was performed on five human gynecological cancer cell lines: AN3, AE7, BG1, HEC1A, and SKUT1B. Exposure to Adolezesin (U73975, Upjohn Co.) was done at near confluency at 0, 0.1, 0.2, 0.5, 1 and 5x, with x = 10 pg/ml as reference concentration, for 90 min. Cell samples were taken by trypsinization at 0, 24, 48, 72, 96, and 168 h for flow cytometry. The ATP chemosensitivity assays were performed on the above cell lines to establish dose/response curves. Flow-cytometric analyses revealed that there was a spectrum of cell-cycle perturbations, which included biphasic S and G2 blocks, reverse dose-dependent G2 blocks, and a sequential relationship of S and G2 blocks. This study demonstrated that the cell kinetic response to Adolezesin depended on several variables such as cell lines, drug sensitivity, concentrations, and sampling time. Because of this multivariable dependence and the lack of correlation with cytotoxicity, it would be difficult to use cell kinetic pertubations to predict chemotherapeutic response.

The impact of National Health Service Corps physicians in the lowering perinatal mortality rate in Dade County, Florida.

In some parts of Dade County, Florida, perinatal mortality rates have revealed serious problems in the delivery of health care to poor pregnant women. From 1982-1985, the reported perinatal mortality rates varied from 32-36 per 1000 live births, more than double the national average. Under the leadership of the Primary Health Care Consortium of Dade County (a federation of community health centers and other primary care providers), National Health Service Corps obstetricians and pediatricians served inner-city, medically needy patients as part of a coordinated perinatal plan from 1987-1989. Data on fetal and neonatal deaths, collected from census tracts adjacent to the community health centers, were used to study the impact of Corps obstetrician and pediatrician placement. The respective perinatal mortality rates were compared with those of 1986 as historic controls. Within a year, the overall perinatal mortality rate was reduced by 45%. As a result, an estimated 320 lives were saved between 1987-1989. This public health achievement represents a measurable impact due to assignment of National Health Service Corps physicians and can be used as a working model to reduce perinatal mortality in medically underserved communities in the United States.

Fetal death following antepartum fetal heart rate testing: a review of 65 cases.

The nonstress test (NST) remains in widespread use for antepartum fetal surveillance. Our institutional experience with 14,028 patients and 38,645 tests over eight years reveals a fetal death rate of 2.6 per 1000 within seven days of a reactive NST. The autopsy findings of 53 fetal deaths are presented. The most common findings, in descending order of frequency, were meconium aspiration, perinatal infection, and abnormal umbilical cord position. These findings support changes we have made in our antepartum assessment protocols.

Peripartum colloid osmotic pressures: correlation with serum proteins.

Colloid osmotic pressure is a principal regulator of capillary fluid exchange. Alterations in colloid osmotic pressure in preeclamptic patients, as well as significant peripartum changes in colloid osmotic pressure in normotensive patients, are reported. In a study of 72 normotensive and preeclamptic patients, peripartum colloid osmotic pressure, serum albumin, and total serum protein were compared. Both groups exhibited significantly lower colloid osmotic pressure in the postpartum period than that measured antepartum. The mean antepartum colloid osmotic pressure in preeclamptic patients was significantly lower than in normotensive subjects. Regression equations were calculated [colloid osmotic pressure = 5.21 (total serum protein) -11.4 (r2 = 0.851)] and [colloid osmotic pressure = 8.1 (serum albumin) -8.2 (r2 = 0.891)]. Within the physiologic ranges most commonly reported for normotensive and preeclamptic patients, the use of these equations allowed calculation of colloid osmotic pressure to within 10% of measured values in 75 and 80% of the cases, respectively. Where direct measurement of colloid osmotic pressure is not readily available, calculated values may be helpful in patient management.

In vitro evaluation of a novel chemotherapeutic agent, Adozelesin, in gynecologic-cancer cell lines.

Adozelesin is a derivative of an extremely cytotoxic compound, CC1065. This entirely new class of drug binds preferentially to DNA and facilitates alkylation reaction. In the present study, we used the adenosine triphosphate (ATP) chemosensitivity assay to compare the cytotoxic potency of Adozelesin with that of common chemotherapeutic agents in ten gynecologic-cancer cell lines. Flow cytometry was also used to study its effects on cell-cycle kinetics. The mean drug concentrations required to produce a 50% reduction in ATP levels as compared with controls [IC50] were: Adriamycin, 0.17 +/- 0.06 microM; 4OH-Cytoxan, 18 +/- 3 microM; cisplatin, 17 +/- 7 microM; 5-fluorouracil, 183 +/- 116 microM; and Adozelesin, 11.0 +/- 5.4 pM. Thus, Adozelesin was 10(4) - 10(7) times more potent than Adriamycin, cisplatin, 5-fluorouracil, and Cytoxan. Cell kinetics studies revealed significant S and G2 blocks such as those previously reported for other alkylating agents.

Biologic effects of equilin sulfate in postmenopausal women.

In order to determine the relative potency of equilin sulfate (EqS), a major constituent of conjugated equine estrogens, 15 women received oral doses of EqS (0.15, 0.31, and 0.625 mg) for 25 days. Doses of 0.31 and 0.625 mg significantly stimulated hepatic globulins. This stimulatory effect ranged from being 1.5 to 8 times greater than the effects of comparable doses of estrone sulfate and conjugated equine estrogens. A significant stimulation in high-density lipoprotein-cholesterol occurred with as little as 0.15 mg of EqS. Elevations in the high-density lipoprotein/low-density lipoprotein-cholesterol ratio occurred with EqS, which resulted in an approximately 4-fold greater response than that achieved with comparable doses of conjugated equine estrogens. The fasting urinary calcium/creatinine ratio was only significantly lowered with 0.625 mg of EqS and was less potent than conjugated equine estrogens in this regard. It is concluded that EqS is a potent estrogen that contributes significantly to the hepatic stimulatory effects of conjugated equine estrogens. These data also provide support for the suggestion that there may be a dissociation in potency between estrogenic effects on liver and bone.

In vivo covalent binding of cismethrin and bioresmethrin to hepatic proteins.

The covalent binding level of [14C]alcohol-labelled cismethrin, bioresmethrin and/or their metabolites to hepatic proteins was measured after a single i.v. injection of pyrethroids in rats pretreated with malathion. In the first control group, the radiolabel binding level was different for cismethrin (35.3 pmol X mg-1 protein) and bioresmethrin (22.6 pmol X mg-1 protein) and in the treated rats, the amount of binding was reduced similarly for the two pyrethroids (13 pmol X mg-1 protein). After 13 days of chronic i.p. treatment, the covalent binding level on microsomal protein was 3 times higher for cismethrin than for bioresmethrin and the ratio of cismethrin to bioresmethrin covalent binding level was similar to that after a single i.v. injection. It is suggested that the difference in covalent binding distribution and concentration in the various subcellular fractions of liver was due to the different routes of metabolism of the two resmethrin isomers.

Hepatic portal venous gas following emergency endoscopic sclerotherapy of gastric varices.

Hepatic portal venous gas (HPVG) is a rare condition, usually associated with extended bowel necrosis or intra-abdominal infection. Herein, we report a case of HPVG following endoscopic sclerotherapy for bleeding gastric varices. A 50-year-old female with a history of alcoholic liver disease was referred to our hospital because of hematemesis. Emergency endoscopic sclerotherapy was performed to control bleeding gastric varices. Twelve hours later, HPVG was demonstrated by ultrasound and confirmed by duplex sonography, which spontaneously resolved 2 hours later. The patient remained well throughout this time, and was released with no major sequelae. This case supports the view that HPVG can also present as a benign finding, in particular, following diagnostic and therapeutic procedures of the gut. The underlying cause determines the clinical significance and prognosis of HPVG.

Ureteral obstruction and hydronephrosis as a complication of tuboovarian abscess. A case report.

Ureteral obstruction and hydronephrosis are rare complications of pelvic inflammatory disease. A woman developed severe unilateral urinary tract obstruction caused by a tuboovarian abscess, requiring ureteral stent placement.