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Single cell biology has the potential to elucidate many critical biological processes and diseases, from development and regeneration to cancer. Single cell analyses are uncovering the molecular diversity of cells, revealing a clearer picture of the variation among and between different cell types. New techniques are beginning to unravel how differences in cell state-transcriptional, epigenetic, and other characteristics-can lead to different cell fates among genetically identical cells, which underlies complex processes such as embryonic development, drug resistance, response to injury, and cellular reprogramming. Single cell technologies also pose significant challenges relating to processing and analyzing vast amounts of data collected. To realize the potential of single cell technologies, new computational approaches are needed. On March 17-19, 2021, experts in single cell biology met virtually for the Keystone eSymposium "Single Cell Biology" to discuss advances both in single cell applications and technologies.

The blood–brain barrier (BBB) restricts free access of molecules between the blood and the brain and is essential for regulating the neural microenvironment. Here, we describe how the BBB was initially characterized and how the current field evaluates barrier properties. We next detail the cellular nature of the BBB and discuss both the conservation and variation of BBB function across taxa. Finally, we examine our current understanding of mouse and zebrafish model systems, as we expect that comparison of the BBB across organisms will provide insight into the human BBB under normal physiological conditions and in neurological diseases.

The aim of the current study was to evaluate the effectiveness of intraoperative neuromonitoring (INM) as an adjunct in performing tarsal tunnel decompression surgery. We reviewed 38 patients who met inclusion criteria. INM was used to measure the voltage of the abductor hallucis and digiti quinti muscles both before and after decompression. Observed changes intraoperatively were acute and within minutes of the decompression performed by the surgeon. Patient outcomes were ascertained from clinical findings and classified as excellent, fair, or poor. Patient outcomes and the voltage change were measured and assessed for association, and statistically significant differences were found between outcome groups. Of the 38 patients, 29 (76%) had excellent outcomes, with a mean change in microvolts of 2088.28 ± 1172.44 (684%) (p = .0004) and 2173.24 ± 1228.39 (742%) (p = .0014) for abductor hallucis and abductor digiti quinti, respectively. The study supports INM as a useful adjunct in performing tarsal tunnel decompression.

Aneuploidy, a hallmark of cancer cells, poses an appealing opportunity for cancer treatment and prevention strategies. Using a cell-based screen to identify small molecules that could selectively kill aneuploid cells, we identified the compound N-[2hydroxy-1-(4-morpholinylmethyl)-2-phenylethyl]-decanamide monohydrochloride (DL-PDMP), an antagonist of UDP-glucose ceramide glucosyltransferase. DL-PDMP selectively inhibited proliferation of aneuploid primary mouse embryonic fibroblasts and aneuploid colorectal cancer cells. Its selective cytotoxic effects were based on further accentuating the elevated levels of ceramide, which characterize aneuploid cells, leading to increased apoptosis. We observed that DL-PDMP could also enhance the cytotoxic effects of paclitaxel, a standard-of-care chemotherapeutic agent that causes aneuploidy, in human colon cancer and mouse lymphoma cells. Our results offer pharmacologic evidence that the aneuploid state in cancer cells can be targeted selectively for therapeutic purposes, or for reducing the toxicity of taxane-based drug regimens., National Cancer Institute (U.S.) (Grant P30-CA14051)

A method for determining a safety range for non-cancer risks is proposed, similar in concept to the range used for cancer in the management of waste sites. This safety range brings transparency to the chemical specific Reference Dose or Concentration by replacing their “order of magnitude” definitions with a scientifically-based range. EPA’s multiple RfCs for trichloroethylene (TCE) were evaluated as a case study. For TCE, a multi-endpoint safety range was judged to be 3 μg/m3 to 30 μg/m,3 based on a review of kidney effects found in NTP (1988), thymus effects found in Keil et al. (2009) and cardiac effects found in the Johnson et al. (2003) study. This multi-endpoint safety range is derived from studies for which the appropriate averaging time corresponds to different exposure durations, and, therefore, can be applied to both long- and short-term exposures with appropriate consideration of exposure averaging times. For shorter-term exposures, averaging time should be based on the time of cardiac development in humans during fetal growth, an average of approximately 20–25 days.

Introduction. True aneurysms of the extracranial internal carotid artery are rare lesions. Surgical treatment is considered to be the best therapeutic option. However, the use of the intraluminal shunt remains controversial. Case report. We reported a case of a giant extracranial internal carotid artery aneurysm treated by reconstructive surgery. A 76-year-old woman was referred with a pulsatile mass inside her mouth, associated with dizziness and dysarthria. There was no history of cerebrovascular symptoms, neck pain, or cervical trauma. A magnetic resonance scan showed a 45 mm aneurysm of the internal carotid artery (ICA), and kinking of ICA. Angiography demonstrated a saccular ICA aneurysm, with a lengthening and tortuosity of the ICA. The aneurysm and the carotid artery branches were easily exposed through a standard anterior cervical incision. After resection of the aneurysm, a Javid shunt was inserted between the common and internal carotid arteries, and end-to-end repair of ICA was easily performed due to ICA redundancy. The aneurysm was of atherosclerotic origin. Four months after the operation, the patient showed a complete recovery from peripheral neurological deficit. Discussion. Our results show that surgical reconstruction is a satisfactory therapeutic choice in the management of extracranial carotid artery aneurysms in order to avoid rupture, thromboembolism and cerebrovascular insufficiency. To date, there has been little experience with endoluminal exclusion techniques and the long-term effectiveness is still uncertain. .

Aneuploidy is frequently associated with disease and developmental abnormalities. It is also a key characteristic of cancer. Several model systems have been developed to study the role of chromosomal instability and aneuploidy in tumorigenesis. The results are surprisingly complex, with the conditions sometimes promoting and sometimes inhibiting tumour formation. Here, we review the effects of aneuploidy and chromosomal instability in cells and model systems of cancer, propose a model that could explain these complex findings and discuss how the aneuploid condition could be exploited in cancer therapy.

An aneurysm has been defined as a permanent local dilatation of the diameter of an artery by at least 50% of its normal value. A splenic artery aneurysm is most frequently a visceral artery aneurysm and clinically it is usually asymptomatic but potentially life-threatening at the same time, with the incidence of its rupturing being 2-10% and then the mortality rate ranges from 20 to 36%. A 51-year-old female patient was admitted to the Department of Vascular and Transplantation Surgery in Novi Sad having been found to have a big splenic artery aneurysm during the ultrasound examination of her abdomen after cholecystectomy. The additional diagnostic procedure - computerized tomography of the abdomen with i.v contrast subtraction angiography-confirmed the splenic artery aneurysm to have the diameter of 5 cm and therefore the elective surgical treatment was indicated after the preoperative preparation and risk assessment. The aneurysm was exposed through Chevron incision, and the detailed surgical exploration was done after the omental bursa had been opened. The aneurysmectomy and the reconstruction of the splenic artery by the termino-terminal anastomosis were performed after the weakening of the wall had been verified. The biopsies of the liver and the aneurysmal sac were done during the surgery. The pathohistological finding confirmed the atherosclerotic etiology of the aneurysm. Since the postoperative course was normal, the patient was discharged on the eighth postoperative day.

microRNAs play a critically important role in a wide array of biological processes including those implicated in cancer, neuro-degenerative and metabolic disorders, and viral infection. Although we have begun to understand microRNA biogenesis and function, experimental demonstration of their functional effects and the molecular mechanisms by which they function remains a challenge. Members of the let-7/miR-98 family play a critical role in cell cycle control with respect to differentiation and tumorigenesis. In this study, we show that exogenous addition of pre-let-7 in primary human fibroblasts results in a decrease in cell number and an increased fraction of cells in the G2/M cell cycle phase. Combining microarray techniques with DNA sequence analysis to identify potential let-7 targets, we discovered 838 genes with a let-7 binding site in their 3′-untranslated region that were down-regulated upon overexpression of let-7b. Among these genes is cdc34, the ubiquitin-conjugating enzyme of the Skp1/cullin/F-box (SCF) complex. Cdc34 protein levels are strongly down-regulated by let-7 overexpression. Reporter assays demonstrated direct regulation of the cdc34 3′-untranslated region by let-7. We hypothesized that low Cdc34 levels would result in decreased SCF activity, stabilization of the SCF target Wee1, and G2/M accumulation. Consistent with this hypothesis, small interfering RNA-mediated down-regulation of Wee1 reversed the G2/M phenotype induced by let-7 overexpression. We conclude that Cdc34 is a functional target of let-7 and that let-7 induces down-regulation of Cdc34, stabilization of the Wee1 kinase, and an increased fraction of cells in G2/M in primary fibroblasts.

Aortoenteric fistula represents a communication between aortic and duodenal lumen. It is a very rare complication of aortic aneurysmal disease as well as aortic prosthetic surgery. There are only few surgeons who have seen more than one case of aortoenteric fistula. At the Institute of Surgery one case of aortoenteric fistula was treated. It was well diagnosed at the Institute for Internal Medicine, and then presented to the vascular surgeon who operated immediately. The whole diagnostic and therapeutic procedure was well done, but stenosing carcinoma of ascendent colon was found during the operation. Resection were done leading to the dehiscence of bowel anastomosis and fatal outcome for the patient. This case is instructive in a diagnostic and surgical manner.

Background. Healthy Start is a 3-year demonstration and education research project designed to evaluate the effectiveness of a multidimensional cardiovascular (CV) risk reduction intervention in preschool centers over a 3-year period of time. Methods. Two primary interventions are employed. The first is the preschool food service intervention program designed to reduce the total fat in preschool meals and snacks to less than 30% of calories and reduce the saturated fat to less than 10% of calories. The second major intervention is a comprehensive preschool health education curriculum, focused heavily on nutrition. Results. Effectiveness of the intervention will be determined through evaluation of changes in dietary intake of preschool children at school meals and snacks, especially with respect to intake of total and saturated fat. Evaluation of the education component will include assessment of program implementation by teachers, assessment of changes in nutrition knowledge by preschool children, and assessment of changes in home meals that children consume (total and saturated fat content). Blood cholesterol will be evaluated semiannually to evaluate changes that may be due to modification of dietary intake. Growth and body fatness will also be assessed. Conclusions. While substantial efforts have targeted CV risk reduction and health education for elementary school children, similar efforts aimed at preschool children have been lacking. The rationale for beginning CV risk reduction programs for preschool children is based upon the premise that risk factors for heart disease are prevalent by 3 years of age and tend to track over time, most commonly hypercholesterolemia and obesity, both related to nutrition. Since the behavioral antecedents for nutritional risk factors begin to be established very early in life, it is important to develop and evaluate new educational initiatives such as Healthy Start , aimed at the primary prevention of cardiovascular risk factors in preschool children. The purpose of this publication is to describe the rationale and methods for the Healthy Start project.

This paper analyzes results of 5-year surgical treatment of patients with ruptured abdominal aorta aneurysms (1991.-1995.) at the Clinic for Vascular and Transplantation Surgery of the Institute of Surgery in Novi Sad. 105 patients with abdominal aorta aneurysm underwent surgery, whereas in 31 patients there was a suspicion of rupture and it was confirmed by US and CT examination. One of basic factors to decrease mortality in these patients is early diagnosis and surgery before hemorrhagic shock occurs. Results in hemodynamic stabile patients with blood pressure over 100 mmHg and regular diuresis are much better with mortality of 20%. In order to estimate the correlation of hemodynamic state and outcome of the operation, patients were divided into three groups--hemodynamic stable with blood pressure over 100 mmHg and regular diuresis at admission: hemodynamic unstable patients with signs of mild or moderate shock and blood pressure under 100 mmHg and without initial diuresis which was regulated at the beginning of therapy and hemodynamic unstable patients in severe shock and unmeasurable blood pressure. The highest survival rate (10% mortality) and the least complications occurred in the first group of patients. The total mortality of patients after surgery was 48.48%. Timely diagnosis, suspicion of rupture and adequate first and with urgent transfer to a competent surgical institution are key factors in treatment of this disease and its outcome.

We reviewed a complex nuclear medical method's application for investigating venous circulation of lower extremities--radionuclide venography (RVG) in explaining a case of suspective ileofemoral thrombosis. Suffering from pain and swelling of the right leg, patient T.J. wanted a checkup. After the physical examination, vascular surgeon suspected phlebothrombosis of the right ileofemoral region and immediately sent her to have a radionuclide venography (RVG) (because by Doppler-ultrasonography certain data confirming presence of thrombus in the pelvic region couldn't be gained). On the basis of gathered results vascular surgeon can make a final diagnosis (phlebothrombosis of the right vein femoralis), so that in this case flebography was not necessary. Although performing RVG is complex and requires engagement of experts of different profiles, gathered data are valuable because they cover the shortage of existing diagnostic methods which are most often used in routine work (Doppler-ultrasonography and phlebography). Applying RVG phlebography can be avoided in all patients who are not expected to have operative treatment, and in cases where thrombosis is suspected in deep veins of pelvis, RVG can be performed right away, without Doppler ultrasonography.

From 1988 to 1993 thirty liver resections were performed in thirty patients. Eight were operated for suffering from hepatocellular carcinoma, four from metastasis of colon's adenocarcinoma, five for great hemangiomas and the rest for focal liver changes. Right lobectomy was performed in six cases, as well as two trisegmentectomies and two left lobectomies while segmentectomies in the rest. Periopretive mortality occurred in two cases as two patients died because of postoperative thrombosis of vena portae and massive gastrointestinal bleeding. Recidive of malignant tumors was established in five patients after year and in other five till the second year. Benign tumors are without recidives. Later resection is a safe procedure with a considerable selection of patients, with use of latest technical conveniences, application of grafts on branches of vena portae and with routine application of intraoperative ultrasonography. The paper contains diagnostical postulates, surgical techniques and anatomic and morphologic types of resection.

Hatha Yoga's effects on the posture of 15 ten year-old children and also its effects on the psychophysical condition of 15 grown-ups was studied. As symptoms, during the first examination, 12 of the 15 children had head protrusion, 14 had shortened back extensors, all 15 had bent shoulders, relaxation of the frontal abdominal wall and shortened flexors of both the calf and thigh. The condition of all the children was remarkably better after six months of practice, some of the symptoms having completely disappeared (head protrusion, asymmetry of the shoulders, mamillas and hips, shortening of the pectoralis and back extensors), 9 children still had slight to medium relaxation of the frontal abdominal wall, 8 children still had bent shoulders, and 1 child still had shortened calf and thigh extensors. The adults were in a weak or very weak psychophysical condition, they tired easily, they complained of sleep disturbances, fluctuation of emotional state and irritability. After 3 months of practice, the vital capacity of 8 of the adults tested (53.3%) had increased by 435 ml. The time duration of apnoea had lengthened for all of the practicing adults, but with a truly large variation among them (a median of 14%). The deep waist-bend length of all the practicing adults had lengthened by an average of 9.5 cm, and the average length increase for the 3-minute running test was 42 m. All those who practiced, had experienced an alleviation of psychic difficulties.

Biological, biochemical, and biophysical properties of three lymphocytic choriomeningitis (LCM) virus strains were compared. The biological property examined was the concentration range of virus which would, when injected into neonates, cause a carrier state. The dosage range for the CA1371 and Traub strains was found to be as broad as the limits examined (5 to 100 ld 50 units/mouse). The WCP strain, however, would only produce carriers within a 3 to 5 ld 50 range. The biochemical properties examined were the growth rates in tissue culture and the effect of varying the input ratio of virus to cells. With identical input ratios, the Traub strain reached a peak titer 32 hr after infection. The CA1371 and WCP strain reached their peaks at the 40th hr. With a 10-fold decrease in the amount of CA1371 virus per cell, peak titer (as high as in the above experiments) was not obtained until 56 hr postinfection. The biophysical properties examined were stability in density gradients and inactivation rates at 4C. In potassium tartrate gradients, full recovery of the CA1371 and WCP strain could be achieved. However, inactivation kinetics showed that only the CA1371 strain was much more stable than the Traub-LCM. The realization that marked differences in LCM strains exist is discussed in relation to certain inconsistencies in the literature.

One hundred and thirty-two PTFE bifurcated prosthetic grafts were implanted during the course of a bicentre study conducted at the abovenamed institutions from 1982 to 1986. The study included 118 males and 14 females with an average age of 62 years. One hundred and eighteen patients suffered from aorto-iliac occlusive disease and 14 from abdominal aortic aneurysms (AAA). Five patients had already undergone previous surgery (redo operations), with extirpation of thrombosed Dacron prostheses. Proximal end to end anastomoses were fashioned in 94 cases (71.2%), while end to side anastomoses were performed in 38 cases (28.8%). The distal anastomoses were to the iliac arteries in 11 cases, the common femoral artery in 89 cases and the deep femoral artery in 32 cases.

A new rapid and sensitive method, the single vertical spin autoprofiler (VAP), has been developed for quantitative profiling of the major plasma lipoproteins. The method involves a combination of single vertical spin separation of plasma and continuous on-line analysis of cholesterol. Plasma lipoproteins are first separated by a 45-min spin in a vertical rotor, after which the amount of cholesterol in the effluent of each tube is monitored continuously by a modification of the BMC automated enzymatic cholesterol method; simultaneously, 80% of the sample is diverted by stream-splitting to a fraction collector for further analysis, if desired. VAP not only resolves very low density lipoprotein (VLDL), low density lipoprotein (LDL), and high density lipoprotein (HDL) peaks quantitatively but also detects the presence of intermediate density lipoprotein (IDL) and other lipoprotein variants. VAP was highly reproducible; the inter-run coefficient of variation for cholesterol concentration in VLDL, LDL, and HDL was 4.8%, 2.9%, and 2.4%, respectively. Cholesterol recovery using VAP was 98.5 +/- 3.5%. Lipoprotein-cholesterol profiles of plasma from three major hyperlipoproteinemia phenotypes examined by VAP were qualitatively and quantitatively different from each other and from profiles of normolipidemic individuals. One significant finding was that IDL could be detected in the plasma of all type IV hyperlipoproteinemic subjects examined thus far. Several variant lipoprotein profiles which did not correspond to known phenotypes have also been detected by VAP using plasma from hyperlipidemic as well as from normolipidemic subjects. We submit that VAP is an accurate and rapid method for lipoprotein analysis, either for routine clinical screening or for detailed experimental studies. In addition, VAP provides a visual display of partially to completely resolved lipoprotein classes that is suitable for computer-assisted analysis.-Chung, B. H., J. P. Segrest, J. T. Cone, J. Pfau, J. C. Geer, and L. A. Duncan. High resolution plasma lipoprotein cholesterol profiles by a rapid, high volume semi-automated method.

Summary The symptoms and histopathology of many virus diseases depend not so much on damage to the cells by virus but on the immunological reaction to the infection. The earliest (Traub, 1935) and still extensively studied (Oldstone & Dixon, 1970) infection of this type is murine lymphocytic choriomeningitis. From the in vivo work it has been commonly accepted that lymphocytic choriomengitis virus (LCMV) is intrinsically temperate, but there are numerous examples of LCMV-induced cytopathic effects (c.p.e.) in tissue culture (Pfau & Camyre, 1968). We have recently shown that c.p.e. in LCMV-infected L cells is largely regulated by an interference phenomenon (Welsh & Pfau, 1972). Cell culture-grown stocks of LCMV contain a transmissible component that specifically interferes with LCMV infective centre formation, synthesis and cytolytic activity; this interfering component sediments with the infectious virus particle, fails to pass through a Millipore filter of 25 nm pore size, and is inactivated by heat (60 °C), neutral red and LCMV-immune serum (Welsh & Pfau, 1970, 1972).

IN an earlier report the isolation of a single-stranded DNA from highly purified vaccinia virus was described1. The DNA was extracted under mild conditions with water-saturated phenol and deoxycholate, according to the standard procedure used for obtaining purified and undegraded nucleic acids from many other viruses and micro-organisms2. It was considered unlikely that this single-stranded DNA was derived by denaturation of originally double-stranded DNA as a result of phenol treatment; first, because there are no reports in the extensive literature that phenol extraction at 4° C. can cause such degradation, and secondly because salmon-sperm DNA treated in our laboratory with the identical procedure used for vaccinia showed no evidence of denaturation. Despite repeated attempts to improve the yield of phenol-extracted DNA from vaccinia, the method was quantitatively unsatisfactory as not more than 10–20 per cent of the total viral DNA was recovered. Alternative methods of isolating the DNA from the virus in higher yield and in as pure a form as possible have therefore been investigated.