Some observations on marine phytoplankton kinetics: 2. the effect of nitrate and ammonium concentrations on the growth and uptake rates of the natural population of Ubatuba region, SP (23ºS, 045ºW)

The phytoplankton Ks anã Vmax as a function of ammonium and nitrate concentrations were determined. The growth rate was estimated from measurements on synthesized chlorophyll-α and the cell number in the. culture media. The uptake rate was determined as to the consumption of ammonium and nitrate after the nutrients depletion from culture media.Foram determinadas a Ks e a Vmax do fi toplancton natural, em função da concen tração de amonia e nitrato. A velocida de de crescimento foi determinada como clorofila-a sintetizada e numero de cé lulas no meio de cultura. A velocidade de assimilação foi determinada como o consumo de amonia e nitrato depois do esgotamento desses nutrientes do meio de cultura

Analysis method of intracellular iron accumulated in phytoplankton

Foi desenvolvido um método para análise do ferro acumulado em células de fitoplâncton, usando ferrocianeto de potássio como agente complexante. Com esse objetivo montaram-se duas experiências: uma em que se mostra o acúmulo de ferro em relação à idade das células e uma segunda experiência onde a assimilação é plotada em função da concentração de EDTA no meio de cultura.A colorimetric method for the assessment of iron accumulated in the cells of phytoplankton utilizing potassium ferrocyanide was developed. Two experiences with Phaeodactylum tricornutum and Chlorella sp. were carried out: the first one, on uptake of the iron relatively to the age of the culture: the second one, on the iron uptake by the cells, relatively to different concentrations of the chelator EDTA

Influences on pathologic complete response in breast cancer patients after neoadjuvant chemotherapy

Purpose Pathologic complete response is associated with longer disease-free survival and better overall survival after neoadjuvant chemotherapy in breast cancer patients. We, therefore, evaluated factors influencing pathologic complete response. Methods Patients receiving neoadjuvant chemotherapy from 2015 to 2018 at the Saarland University Hospital were included. Patients’ age, tumor stage, tumor biology, genetic mutation, recurrent cancer, discontinuation of chemotherapy, and participation in clinical trials were extracted from electronic medical records. Binary logistic regression was performed to evaluate the influence of these factors on pathologic complete response. Results Data of 183 patients were included. The median patient’s age was 54 years (22–78). The median interval between diagnosis and onset of chemotherapy was 28 days (14–91); between end of chemotherapy and surgery 28 days (9–57). Sixty-two patients (34%) participated in clinical trials for chemotherapy. A total of 86 patients (47%) achieved pathologic complete response. Patient’s age, genetic mutation, recurrent cancers, or discontinuation of chemotherapy (due to side effects) and time intervals (between diagnosis and onset of chemotherapy, as well as between end of chemotherapy and surgery) did not influence pathologic complete response. Patients with high Ki67, high grading, Her2 positive tumors, as well as patients participating in clinical trials for chemotherapy had a higher chance of having pathologic complete response. Patients with Luminal B tumors had a lower chance for pathologic complete response. Conclusion Particularly patients with high risk cancer and patients, participating in clinical trials benefit most from chemotherapy. Therefore, breast cancer patients can be encouraged to participate in clinical trials for chemotherapy

Factors influencing the time to surgery after neoadjuvant chemotherapy in breast cancer patients

Purpose It is suspected that delayed surgery after neoadjuvant chemotherapy (NACT) leads to a worse outcome in breast cancer patients. We therefore evaluated possible influencing factors of the time interval between the end of NACT and surgery. Methods All patients receiving NACT due to newly diagnosed breast cancer from 2015 to 2017 at the Department of Gynecology, Saarland University Medical Center, were included. The time interval between end of NACT and surgery was defined as primary endpoint. Possible delaying factors were investigated: age, study participation, outpatient and inpatient presentations, implants/expander, MRI preoperatively, discontinuation of chemotherapy, and genetic mutations. Results Data of 139 patients was analyzed. Median age was 53 years (22–78). The time interval between end of NACT and surgery was 28 days (9–57). Additional clinical presentations on outpatient basis added 2 days (p = 0.002) and on inpatient basis added 7 days to time to surgery (p < 0.001). Discontinuation of NACT due to chemotherapy side effects prolonged time to surgery by 8 days (p < 0.001), whereas discontinuation due to disease progress did not delay surgery (p = 0.6). In contrast, a proven genetic mutation shortened time to surgery by 7 days (p < 0.001). Patient’s age, participation in clinical studies, oncoplastic surgery, and preoperative MRI scans did not delay surgery. Conclusion Breast care centers should emphasize a reduction of clinical presentations and a good control of chemotherapy side effects for breast cancer patients to avoid delays of surgery after NACT

Urogynecology in obstetrics: impact of pregnancy and delivery on pelvic floor disorders, a prospective longitudinal observational pilot study

Purpose To assess changes in the pelvic floor anatomy that cause pelvic floor disorders (PFDs) in primigravidae during and after pregnancy and to evaluate their impact on women’s quality of life (QoL). Methods POP-Q and translabial ultrasound examination was performed in the third trimester and 3 months after delivery in a cohort of primigravidae with singleton pregnancy delivering in a tertiary center. Results were analyzed regarding mode of delivery and other pre- and peripartal factors. Two individualized detailed questionnaires were distributed at 3 months and at 12 months after childbirth to determinate QoL. Results We recruited 45 women, of whom 17 delivered vaginally (VD), 11 received a vacuum extraction delivery (VE) and 17 a Cesarean section in labor (CS). When comparing third-trimester sonography to 3 months after delivery, bladder neck mobility increased significantly in each delivery group and hiatal area increased significantly in the VD group. A LAM avulsion was found in two women after VE. Connective tissue weakness (p = 0.0483) and fetal weight at birth (p = 0.0384) were identified as significant risk factors for the occurrence of PFDs in a multivariant regression analysis. Urinary incontinence was most common with 15% and 11% of cases at 3, respectively, 12 months after delivery. 42% of women reported discomfort during sexual intercourse, 3 months after delivery and 24% 12 months postpartum. Although 93% of women engage a midwife after delivery, only 56% participated in pelvic floor muscle training. Conclusion Connective tissue weakness and high fetal weight at birth are important risk factors for the occurrence of PFDs. Nevertheless, more parturients should participate in postpartal care services to prevent future PFDs

Immunohistochemical assessment of PD-L1 expression using three different monoclonal antibodies in triple negative breast cancer patients

Background PD-L1 receptor expression in breast cancer tissue can be assessed with different anti-human PD-L1 monoclonal antibodies. The performance of three specific monoclonal antibodies in a head-to-head comparison is unknown. In addition, a potential correlation of PD-L1 expression and clinico-pathological parameters has not been investigated. Methods This was a retrospective study on tissue samples of patients with histologically confirmed triple negative breast cancer (TNBC). PD-L1 receptors were immune histochemically stained with three anti-human PD-L1 monoclonal antibodies: 22C3 and 28-8 for staining of tumor cell membranes (TC) and cytoplasm (Cyt), SP142 for immune cell staining (IC). Three different tissue samples of each patient were evaluated separately by two observers in a blinded fashion. The percentage of PD-L1 positive tumor cells in relation to the total number of tumor cells was determined. For antibodies 22C3 and 28-8 PD-L1 staining of 0 to  50% was rated "strong positive". Cyt staining was defined as “negative” when no signal was observed and as “positive”, when any positive signal was observed. For IC staining with SP142 all samples with PD-L1 expression ≥ 1% were rated as “positive”. Finally, the relationship between PD-L1 expression and clinico-pathological parameters was analyzed. Results Tissue samples from 59 of 60 enrolled patients could be analyzed. Mean age was 55 years. Both the monoclonal antibodies 22C3 and 28-8 had similar properties, and were positive for both TC in 13 patients (22%) and for Cyt staining in 24 patients (40.7%). IC staining with antibody SP142 was positive in 24 patients (40.7%), who were also positive for Cyt staining. The differences between TC and Cyt staining and TC and IC staining were significant (p = 0.001). Cases with positive TC staining showed higher Ki67 expression compared to those with negative staining, 40 vs 30%, respectively (p = 0.05). None of the other clinico-pathological parameters showed any correlation with PDL1 expression. Conclusions Antibodies 22C3 and 28-8 can be used interchangeably for PD-L1 determination in tumor cells of TNBC patients. Results for Cyt staining with 22C3 or 28-8 and IC staining with SP142 were identical. In our study PD-L1 expression correlates with Ki67 expression but not with OS or DFS

WFPC2 Observations of Compact Star Cluster Nuclei in Low Luminosity Spiral Galaxies

We have used the Wide Field Planetary Camera 2 aboard the Hubble Space Telescope to image the compact star cluster nuclei of the nearby, late-type, low-luminosity spiral galaxies NGC 4395, NGC 4242, and ESO 359-029. We also analyze archival WFPC2 observations of the compact star cluster nucleus of M33. A comparative analysis of the structural and photometric properties of these four nuclei is presented. All of the nuclei are very compact, with luminosity densities increasing at small radii to the resolution limit of our data. NGC 4395 contains a Seyfert 1 nucleus with a distinct bipolar structure and bright associated filaments which are likely due to [OIII] emission. The M33 nucleus has a complex structure, with elongated isophotes and possible signatures of weak activity, including a jet-like component. The other two nuclei are not known to be active, but share similar physical size scales and luminosities to the M33 and NGC 4395 nuclei. The circumnuclear environments of all four of our program galaxies are extremely diffuse, have only low-to-moderate star formation, and appear to be devoid of large quantities of dust. The central gravitational potentials of the galaxies are also quite shallow, making the origin of these types of `naked' nuclei problematic.Comment: to appear in the July 1999 Astronomical Journal; 38 pages (Latex), 5 tables (postscript), 21 figures (gif); postscript versions of the figures may be obtained via anonymous ftp at ftp://ftp.cv.nrao.edu/NRAO-staff/lmatthew/lanl-nucle