Impact of COVID-19 on mechanical complications in ST elevation myocardial infarction

Background

Mechanical complications (MC) give a poor prognosis for ST elevation myocardial infarction (STEMI). Its prevalence had decreased in the era of primary angioplasty, at the expense of free wall rupture (FWR).

Purpose

To analyse the prevalence of post-STEMI MC for two periods, before and after the COVID-19 pandemic.

Methods

Unicentric prospective registration of patients with STEMI admitted between January-2018 and December-2021. They are classified into two groups according to the onset of the pandemic by COVID-19: Pre-COVID: January-2018 to December-2019, and Post-COVID: January-2020 to December-2021. The prevalence of post-STEMI MC is analysed, including ventricular septal rupture (VSR), papillary muscle rupture (PMR) and FWR, and 30-day mortality.

Results

1507 consecutive patients with STEMI (Pre-COVID n=775, Post-COVID n=732) are included. Age 62.9 years vs 63.3 years (p=0.5097). Men 78.1% Vs 79.5% (p=0.493). No differences in cardiovascular risk factors, previous heart infarction or anterior wall STEMI. Primary angioplasty was similar in both groups (92%). The Post-COVID group has a higher prevalence of Killip>I (21.7% vs 17.2% p=0.025) and LVEF ≤40% (27.2% vs 20% p=0.001), and longer symptom onset to balloon dilatation interval (316 min vs 257 min p=0.0004). MC are most developed in Post-COVID (2.6% vs 1.2% p=0.039), at the expense of FWR (1.91% vs 0.3% p=0.001). No significant changes in VSR and PMR prevalence or 30-day mortality. Multivariate analysis identifies the independent predictors of FWR: Age (OR 1.05, p=0.024), Primary angioplasty (OR 0.09, p<0.001), and Post-COVID (OR 6.8, p=0.013).

Conclusions

The COVID-19 pandemic is independently associated with a higher prevalence of FWR, probably due to delayed reperfusion.

Funding Acknowledgement

Type of funding sources: None.

Impact of the COVID-19 pandemic on hospitalizations for acute coronary syndromes: a multinational study

BACKGROUND

COVID-19 has challenged the health system organization requiring a fast reorganization of diagnostic/therapeutic pathways for patients affected by time-dependent diseases such as acute coronary syndromes (ACS).

AIM

To describe ACS hospitalizations, management, and complication rate before and after the COVID-19 pandemic was declared.

DESIGN

Ecological retrospective study. Methods: We analyzed aggregated epidemiological data of all patients > 18 years old admitted for ACS in twenty-nine hub cardiac centers from 17 Countries across 4 continents, from December 1st, 2019 to April 15th, 2020. Data from December 2018 to April 2019 were used as historical period.

RESULTS

A significant overall trend for reduction in the weekly number of ACS hospitalizations was observed (20.2%; 95% confidence interval CI [1.6, 35.4] P = 0.04). The incidence rate reached a 54% reduction during the second week of April (incidence rate ratio: 0.46, 95% CI [0.36, 0.58]) and was also significant when compared to the same months in 2019 (March and April, respectively IRR: 0.56, 95%CI [0.48, 0.67]; IRR: 0.43, 95%CI [0.32, 0.58] p < 0.001). A significant increase in door-to-balloon, door-to-needle, and total ischemic time (p <0.04 for all) in STEMI patents were reported during pandemic period. Finally, the proportion of patients with mechanical complications was higher (1.98% vs. 0.98%; P = 0.006) whereas GRACE risk score was not different.

CONCLUSIONS

Our results confirm that COVID-19 pandemic was associated with a significant decrease in ACS hospitalizations rate, an increase in total ischemic time and a higher rate of mechanical complications on a international scale.

P–492 Knowledge about reproductive health among cohort of oocyte donors in Spain

Study question

What degree of reproductive health knowledge have oocyte donors?

Summary answer

The results of this study reveal that although oocyte donors are aware of the risks of possible fertility disorders, reproductive health knowledge is insufficient

What is known already

Sterility affects approximately 15% of the population of reproductive age, that is, young people. However, the information that young people have about fertility is scarce. Gamete donors are a group especially involved in reproductive issues since they help many people to solve their fertility problems and must undergo numerous tests before being accepted as such. However, there are no studies in Spain that deal with the knowledge that young people and, more specifically, donors, have about reproductive health and fertility

Study design, size, duration

A prospective, cross-sectional multicenter study including oocyte donors at ten fertility clinics performing gamete donation treatment in Spain. During a 2-month period (September-October 2020), 63 donors aged between 19 and 35 years old were recruited consecutively and a total of 63 oocyte donors were included as sample population. Most of them (78%) had not donated before

Participants/materials, setting, methods

54% oocyte donors had secondary education and 43% have achieved university studies. Participants anonymously completed a questionnaire containing 41 questions divided into three sections: sociodemographic characteristics (11 items), knowledge on fertility and reproduction (22 items) and with a Likert scale, response to determine general reproductive health information as well as known risks for fertility disorders (8 items).

Besides descriptive statistics, statistical analysis was performed with Chi square test. p &lt; 0.05 was considered significant

Main results and the role of chance

In the survey 96.8% of the participants reported that they had already known the tests for fertility disorders.

The increasing age of the women was correctly assessed by the participants of the study as a decisive risk factor for fertility, but it was found that exact knowledge was lacking: the decrease of a woman’s fertility by 39.7% was stated to occur on average at the age of 35–40 and by 30% at 40–45. Nevertheless, 66% of donors considered that fertility preservation should be carried out before the age of 35.

61.1% of the non-university donors reported that fertility can drop as a woman ages due to the decreasing number and quality of the remaining eggs. Among university donors, this percentage increases to 92,6% (p:0,034). Merely 47% of the participants informed what they understood that ovarian reserve is and 47.6% of donors believed that women create new eggs every month.

Regarding the known risk factors for fertility, lifestyle was mentioned most frequently by all participants (91,2%), followed by chemo/radiotherapy (83,8%) and smoking, alcohol, and drugs (82,4%). Concerning the influence of the body mass index on fertility, differences were found between non-university (61%) and university donors (88,9%) (p:0,012).

Limitations, reasons for caution

Financial compensation has been found to be a motivating factor for oocyte donors and therefore one could question the representativeness of the participating oocyte donors. It would be of great interest to explore the significance of the financial compensation further.

Wider implications of the findings: The present study reveals an existing requirement for information among oocyte donors, which is not only important for the success of prevention plans but also provides a foundation for possible strategies for the prevention of fertility disorder.

Trial registration number

Not applicable

2422Outcome of histologically-proven fulminant versus acute non-fulminant myocarditis with left ventricular systolic dysfunction. Evidence from the International Registry on Acute Myocarditis

Background

Fulminant myocarditis (FM) is a form of acute myocarditis characterized by severe left ventricular (LV) dysfunction requiring inotropes and/or mechanical circulatory support. Based on a retrospective single-center study published in 2000, patients with FM were considered to have better outcomes than those affected by acute non-fulminant myocarditis (NFM) presenting with LV systolic dysfunction (LVSD). Recently, this tenet was challenged, though substantial disagreement still exists.

Purpose

Aim of the present study is to provide additional evidence on the outcome of FM and to ascertain if patient stratification based on the main histologic subtypes can provide additional prognostic information.

Methods

Two hundred and twenty patients (median age 42 years, 46.3% female) with histologically proven acute myocarditis (onset of symptoms <30 days) presenting with LVSD were included in a retrospective, international registry comprising 16 tertiary hospitals in the United States, Europe, and Japan. The primary endpoint was the occurrence of cardiac death or heart transplant (HTx) within 60 days from admission and at long-term follow-up.

Results

Patients with FM (N=165) had significantly higher rates of cardiac death and HTx compared with those with NFM (N=55), both at 60 days (28.0% vs. 1.8%, p=0.0001) and at 7-year follow up (47.7% vs. 10.4%, p<0.0001; Figure). At Cox-multivariate analysis, the histologic subtype emerged as a further variable affecting outcome in FM patients, with giant cell myocarditis having a significantly worse prognosis compared with eosinophilic and lymphocytic myocarditis both at 60 days (62.5% vs. 26.3% vs. 21.0%) and at 3 years (81.3% vs. 39.9% vs. 37.3%, overall p<0.0001). In a sub-analysis including only adults with lymphocytic myocarditis, the main endpoints occurred more frequently in FM compared with NFM both at 60 days (19.5% vs. 0%, p=0.005) and up to 7 years (41.4% vs. 3.1%, p=0.0004).

Outcome of FM vs NFM

Conclusions

The results of this international registry confirm that patients with FM have higher rates of cardiac death and HTx both in the short and long-term compared with patients with NFM. Furthermore, we provide evidence that the histologic subtype of FM carries independent prognostic value, highlighting the need for timely endomyocardial biopsy in this condition.

Acknowledgement/Funding

None

Risk-adjusted early invasive strategy in patients with non-ST-segment elevation acute coronary syndrome in Intensive Cardiac Care Units

OBJECTIVE

Current guidelines recommend a risk-adjusted early invasive strategy (EIS) in patients with non-ST-segment elevation acute coronary syndrome (NSTEACS). The present study assesses the application if this strategy, the conditioning factors and prognostic impact upon patients with NSTEACS admitted to Intensive Cardiac Care Units (ICCU).

DESIGN

A prospective cohort study was carried out.

SETTING

The ICCUs of 8 hospitals in Catalonia (Spain).

PATIENTS

Consecutive patients with NSTEACS between October 2017 and March 2018. The risk profile was defined by the European Society of Cardiology criteria.

INTERVENTIONS

EIS was defined as the performance of coronary angiography within the first 6hours in patients at very high-risk or within 24hours in high-risk patients.

OUTCOME VARIABLES

Mortality or readmission at 6 months.

RESULTS

A total of 629 patients were included (mean age 66.6 years), of whom 225 (35.9%) were at very high risk, and 392 (62.6%) at high risk. Most patients (96.2%) underwent an invasive strategy. EIS was performed in 284 patients (45.6%), especially younger patients with fewer comorbidities. These patients had a shorter ICCU and hospital stay, as well as a lesser incidence of ACS, revascularization and death or readmission at 6 months. After adjusting for confounders, the association between EIS and death or readmission at 6 months remained significant (hazard ratio: .66, 95% confidence interval .45-.97; P=.035).

CONCLUSIONS

The EIS was performed in a minority of NSTEACS admitted to ICCU, being associated with better outcomes.

BDNF and AMPA receptors in the cNTS modulate the hyperglycemic reflex after local carotid body NaCN stimulation

The application of sodium cyanide (NaCN) to the carotid body receptors (CBR) (CBR stimulation) induces rapid blood hyperglycemia and an increase in brain glucose retention. The commissural nucleus tractus solitarius (cNTS) is an essential relay nucleus in this hyperglycemic reflex; it receives glutamatergic afferents (that also release brain derived neurotrophic factor, BDNF) from the nodose-petrosal ganglia that relays CBR information. Previous work showed that AMPA in NTS blocks hyperglycemia and brain glucose retention after CBR stimulation. In contrast, BDNF, which attenuates glutamatergic AMPA currents in NTS, enhances these glycemic responses. Here we investigated the combined effects of BDNF and AMPA (and their antagonists) in NTS on the glycemic responses to CBR stimulation. Microinjections of BDNF plus AMPA into the cNTS before CBR stimulation in anesthetized rats, induced blood hyperglycemia and an increase in brain arteriovenous (a-v) of blood glucose concentration difference, which we infer is due to increased brain glucose retention. By contrast, the microinjection of the TrkB antagonist K252a plus AMPA abolished the glycemic responses to CBR stimulation similar to what is observed after AMPA pretreatments. In BDNF plus AMPA microinjections preceding CBR stimulation, the number of c-fos immunoreactive cNTS neurons increased. In contrast, in the rats microinjected with K252a plus AMPA in NTS, before CBR stimulation, c-fos expression in cNTS decreased. The expression of AMPA receptors GluR2/3 did not change in any of the studied groups. These results indicate that BDNF in cNTS plays a key role in the modulation of the hyperglycemic reflex initiated by CBR stimulation.

Mixing effects in the crystallization of supercooled quantum binary liquids

By means of Raman spectroscopy of liquid microjets, we have investigated the crystallization process of supercooled quantum liquid mixtures composed of parahydrogen (pH2) or orthodeuterium (oD2) diluted with small amounts of neon. We show that the introduction of the Ne impurities affects the crystallization kinetics in terms of a significant reduction of the measured pH2 and oD2 crystal growth rates, similarly to what found in our previous work on supercooled pH2-oD2 liquid mixtures [Kühnel et al., Phys. Rev. B 89, 180201(R) (2014)]. Our experimental results, in combination with path-integral simulations of the supercooled liquid mixtures, suggest in particular a correlation between the measured growth rates and the ratio of the effective particle sizes originating from quantum delocalization effects. We further show that the crystalline structure of the mixtures is also affected to a large extent by the presence of the Ne impurities, which likely initiate the freezing process through the formation of Ne-rich crystallites.

Nitric oxide in the solitary tract nucleus (STn) modulates glucose homeostasis and FOS-ir expression after carotid chemoreceptor stimulation

We evaluate in rats the role of NO in the solitary tract nucleus (STn) after an anoxic stimulus to carotid body chemoreceptor cells (CChrc) with cyanide (NaCN), on the hyperglycemic reflex with glucose retention by the brain (BGR) and FOS expression (FOS-ir) in the STn. The results suggest that nitroxidergic pathways in the STn may play an important role in glucose homeostasis. A NO donor such as sodium nitroprusside (NPS) in the STn before CChrc stimulation increased arterial glucose level and significantly decreased BGR. NPS also induced a higher FOS-ir expression in STn neurons when compared to neurons in control rats that only received artificial cerebrospinal fluid (aCSF) before CChrc stimulation. In contrast, a selective NOS inhibitor such as Nomega-nitro-L-arginine methyl ester (L-NAME) in the STn before CChrc stimulation resulted in an increase of both, systemic glucose and BGR above control values. In this case, the number of FOS-ir positive neurons in the STn decreased when compared to control or to NPS experiments. FOS-ir expression in brainstem cells suggests that CChrc stimulation activates nitroxidergic pathways in the STn to regulate peripheral and central glucose homeostasis. The study of these functionally defined cells will be important to understand brain glucose homeostasis.

Low-temperature inelastic collisions between hydrogen molecules and helium atoms

Inelastic H(2):He collisions are studied from the experimental and theoretical points of view between 22 and 180 K. State-to-state cross sections and rates are calculated at the converged close-coupling level employing recent potential energy surfaces (PES): The MR-PES [J. Chem. Phys. 100, 4336 (1994)], and the MMR-PES and BMP-PESs [J. Chem. Phys. 119, 3187 (2003)]. The fundamental rates k(2-->0) and k(3-->1) for H(2):He collisions are assessed experimentally on the basis of a master equation describing the time evolution of rotational populations of H(2) in the vibrational ground state. These populations are measured in the paraxial region of supersonic jets of H(2)+He mixtures by means of high-sensitivity and high spatial resolution Raman spectroscopy. Good agreement between theory and experiment is found for the k(2-->0) rate derived from the MR-PES, but not for the BMP-PES. For the k(3-->1) rate, which is about one-third to one-half of k(2-->0), the result is less conclusive. The experimental k(3-->1) rate is compatible within experimental error with the values calculated from both PESs. In spite of this uncertainty, the global consistence of experiment and theory in the framework of Boltzmann equation supports the MR-PES and MMR-PESs, and the set of gas-dynamic equations employed to describe the paraxial region of the jet at a molecular level.

Rotranslational state-to-state rates and spectral representation of inelastic collisions in low-temperature molecular hydrogen

Inelastic collisions in natural H2 are studied from the experimental and theoretical points of view between 10 and 140 K. Rotational populations and number densities measured by Raman spectroscopy along supersonic expansions of H2 provide the link between experimental and theoretical rotranslational state-to-state rate coefficients of H2 in the vibrational ground state. These rates are calculated in the close-scattering approach with the MOLSCAT code employing a recent ab initio H2-H2 potential. The calculated rates are assessed by means of a master equation describing the time evolution of the experimental rotational populations. The feasibility for obtaining the rates on the sole basis of the experiment is discussed. The dominant processes j(1)j(2)-->j'(1)j'(2) in the investigated thermal range are found to be 21-->01 >30-->12 >31-->11, proving the importance of double processes such as 30-->12. Good agreement is found between theory and experiment, as well as with earlier ultrasonic measurements of relaxation times. A spectral representation is proposed in order to visualize quantitatively the collisional contributions in any nonequilibrium time evolving process.

Inelastic collisions in para-H2: translation-rotation state-to-state rate coefficients and cross sections at low temperature and energy

We report an experimental determination of the k(00-->02) rate coefficient for inelastic H(2):H(2) collisions in the temperature range from 2 to 110 K based on Raman spectroscopy data in supersonic expansions of para-H(2). For this purpose a more accurate method for inverting the master equation of rotational populations is presented. The procedure permits us to reduce the measured k(00-->02) rate coefficient to the corresponding sigma(00-->02) cross section in the range of precollisional energy from 360 to 600 cm(-1). Numerical calculations of sigma(00-->02) carried out in the frame of the coupled channel method are also reported for different intermolecular potentials of H(2). A good agreement is found between the experimental cross section and the numerical one derived from Diep and Johnson's potential [J. Chem. Phys. 112, 4465 (2000)].

Raman spectroscopy of small para-H2 clusters formed in cryogenic free jets

Small para-H2 clusters (pH2)N with N=2,...,8 have been identified by Raman spectroscopy in cryogenic free jets of the pure gas, near the Q(0) Raman line of the H2 monomer. The high resolution in space, time, and number size makes it possible to follow their growth kinetics with distance from the orifice. At lower source temperatures liquid clusters appear early in the expansion and then undergo a gradual phase transition to the solid state. The technique is very promising for exploring superfluidity in pure (pH2)N clusters.

Biweekly paclitaxel plus gemcitabine in advanced breast cancer: phase II trial and predictive value of HER2 extracellular domain

BACKGROUND

We wanted to assess the toxicity and efficacy of paclitaxel plus gemcitabine in advanced breast cancer and to confirm whether circulating HER2 extracellular domain (ECD) correlates with treatment response.

PATIENTS AND METHODS

Forty-three patients received paclitaxel 150 mg/m2 followed by gemcitabine 2500 mg/m2, both on day 1 of 14-day cycles, with a maximum of eight cycles. Serum levels of HER2 ECD were assessed by ELISA.

RESULTS

All patients were evaluable for toxicity and 42 for efficacy. Overall toxicity was low. Grade 3 neutropenia occurred in 12% of patients and grade 4 in 17%, and other grade 3 toxicities in <5%. One patient had an allergic infusion reaction. Overall response rate was 71% [95% confidence interval (CI) 62% to 81%], with 11 patients achieving a complete response (26%). With a median follow-up of 26 months, the median time to progression was 16.6 months. Response rate correlated significantly with HER2 ECD, with 42% of HER2 ECD-positive patients responding versus 83% of HER2 ECD-negative patients (P = 0.02). Furthermore, response duration was shorter in patients with positive HER2 ECD levels (7.9 versus 14.4 months; P = 0.04).

CONCLUSIONS

Paclitaxel plus gemcitabine given as an every 2-weeks schedule is a well tolerated and active regimen in advanced breast carcinoma. This is an attractive combination to use when anthracyclines are not indicated, such as in HER2 positive cases that receive trastuzumab. In addition, elevated levels of HER2 ECD adversely affect the efficacy of treatment.

[Treatment of immune thrombocytopenic purpura in Pediatrics. Therapeutic efficacy of a regional intravenous immunoglobulin G]

Immune thrombocytopenic purpura (ITP) is a bleeding disorder characterized by accelerated splenic removal of platelets opsonized with autoantibodies. Several different treatments have been tried in acute ITP patients, including intravenous immunoglobulin (IVIG) therapy. The aim of this paper was to assess the therapeutic efficacy, clinical tolerance and viral safety of Inmunoglobulina G Endovenosa-UNC, manufactured by Laboratorio de Hemoderivados, Cordoba National University, in the treatment of acute ITP patients. A prospective longitudinal study was carried out on 8 children, who were admitted to the Hospital de Niños de Córdoba, from July 1998 to June 1999. A dose of 1 g/Kg/day of Inmunoglobulina G Endovenosa-UNC was administered to those children whose platelet values remained < or = 20,000/mm3, 21 days after the first IVIG cycle. The observed results led us to conclude that Inmunoglobulina G Endovenosa-UNC is well tolerated and therapeutically effective in the treatment of acute ITP in children, with platelet values recovery, similar to those obtained with other IVIG. Moreover, it proved to be virally safe since the 8 patients were non reactive for viral markers of hepatitis B, hepatitis C and human immunodeficiency, 12 months after ending the treatment.

Prognostic value of cytosolic p53 protein in breast cancer

The prognostic value of cytosolic p53 protein was evaluated in 458 operable breast carcinomas by immunoblotting using the monoclonal antibody PAb 1801. Two hundred and five carcinomas (45%) showed positive p53 accumulation and 55% were p53 negative. When comparing p53 positivity and other clinicopathological parameters, significant differences were found with younger age (p = 0.017), premenopausal status (p = 0.003), increasing tumor size (p = 0.026), negative estrogen receptor (p = 0.003) and negative progesterone receptor (p = 0.047), but not with histologic grade, axillary lymph node status, stage or erbB-2 expression. With a median follow-up of 34 months (range 3-70), relapse has occurred in 73 patients. Disease-free survival curves showed that patients with p53-positive tumors had a significantly shorter disease-free survival than patients with p53-negative carcinomas (log-rank test, p = 0.027). A multivariate analysis of disease-free survival showed that p53, tumor size, histologic grade and progesterone receptor had significant independent prognostic value. The immunoblotting technique was controlled with p53 immunohistochemistry in 94 paired samples. We obtained a statistically significant correlation (p = 0.0004) between the two methods. Our results show that the immunoblotting technique offers an alternative approach in evaluating the p53 status of breast biopsy material using cytosolic extracts, and confirm that p53 accumulation is a significant independent indicator of a poor prognosis in operable breast carcinoma.

Arginine-vasopressin in nucleus of the tractus solitarius induces hyperglycemia and brain glucose retention

Hypothalamic arginine-vasopressin (AVP) plays an important role both as a neurotransmitter and hormone in the regulation of blood glucose and feeding behavior. AVP-containing axons from the parvocellular subdivision of paraventricular nucleus of the hypothalamus terminate in the nucleus of the tractus solitarius (NTS), but the function of this projection is not known. Interestingly, the NTS also receives afferent information from the carotid body and other peripheral receptors involved in glucose homeostasis. We have previously reported that stimulation of the carotid body receptors initiates a hyperglycemic reflex and increases brain glucose retention. Here we show that direct administration of micro-doses of AVP into the NTS of anesthetized or awake rats rapidly increased the levels of blood glucose concentration and brain arterio-venous (A-V) glucose difference. This effect was not observed when the same doses of AVP were injected in the brainstem outside NTS. Arginine-vasopressin antagonist microinjections alone produced a small but significant reduction in brain A-V glucose. Pre-administered VP1-receptor antagonist [beta-mercapto-beta,beta-cyclopentamethylene-propionyl(1),O-Me-Tyr(2),Arg(8)]vasopressin blocked the effects of AVP. These results indicate that AVP acting on its receptors locally within the NTS participates in glucose homeostasis, increasing both blood glucose concentration and brain A-V glucose differences. Hypothalamic AVP may facilitate hyperglycemic responses initiated by peripheral signals processed at the level of the NTS.

Effects of gamma-linolenic acid and oleic acid on paclitaxel cytotoxicity in human breast cancer cells

It has been suggested that dietary interventions may improve the effectiveness of cancer chemotherapy. We have examined the combined in vitro cytotoxicity of paclitaxel and the fatty acids gamma-linolenic acid (GLA, 18:3n-6) and oleic acid (OA, 18:1n-9) in human breast carcinoma MDA-MB-231 cells. The effect of fatty acids on paclitaxel chemosensitivity was determined by comparing IC(50) and IC(70) (50 and 70% inhibitory concentrations, respectively) obtained when the cells were exposed to IC(50) and IC(70) levels of paclitaxel alone and fatty acids were supplemented either before or during the exposure to paclitaxel. The 3-4,5-dimethylthiazol-2-yl-2,5-diphenyl-tetrazolium bromide (MTT) assay was used to determine cell growth inhibition. GLA by itself showed antiproliferative effects, and a possible GLA-paclitaxel interaction at the cellular level was assessed by the isobologram and the combination-index (CI) methods. Isobole analysis at the isoeffect levels of 50 and 70% revealed that drug interaction was predominantly synergistic when GLA and paclitaxel were added concurrently for 24 h to the cell cultures. Interaction assessment using the median-effect principle and the combination-index (CI) method showed that exposure of MDA-MB-231 cells to an equimolar combination of concurrent GLA plus paclitaxel for 24 h resulted in a moderate synergism at all effect levels, consistent with the results of the isobologram analysis. When exposure to GLA (24 h) was followed sequentially by paclitaxel (24 h) only an additive effect was observed. The GLA-mediated increase in paclitaxel chemosensitivity was only partially abolished by Vitamin E, a lipid peroxidation inhibitor, suggesting a limited influence of the oxidative status of GLA in achieving potentiation of paclitaxel toxicity. When OA (a non-peroxidisable fatty acid) was combined with paclitaxel, an enhancement of chemosensitivity was found when OA was used concurrently with paclitaxel, although less markedly than with GLA. Pretreatment of MDA-MB-231 cells with OA for 24 h prior to a 24 h paclitaxel exposure produced greater enhancement of paclitaxel sensitivity at high OA concentrations than the concurrent exposure to OA and paclitaxel. The OA-induced sensitisation to paclitaxel was not due to the cytoxicity of the fatty acid itself. When these observations were extended to three additional breast carcinoma cell lines (SK-Br3, T47D and MCF-7), simultaneous exposure to GLA and paclitaxel also resulted in synergism. GLA preincubation followed by paclitaxel resulted in additivity for all cell lines. Simultaneous exposure to paclitaxel and OA enhanced paclitaxel cytotoxicity in T47D and MCF-7 cells, but not in SK-Br3 cells, whereas preincubation with OA failed to increase paclitaxel effectiveness in all three cell lines. For comparison, the effects of other fatty acids on paclitaxel chemosensitivity were examined: GLA was the most potent at enhancing paclitaxel cytotoxicity, followed by alpha-linolenic acid (ALA; 18:3n.3), eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3), whereas linoleic acid (LA; 18:2n-6) did not increase paclitaxel toxicity. These findings provide experimental support for the use of fatty acids as modulators of tumour cell chemosensitivity in paclitaxel-based therapy.

Raman spectroscopy of hypersonic shock waves

Raman spectroscopy is shown to be an efficient diagnostic methodology for the study of hypersonic shock waves. As a test, absolute density and rotational population profiles have been measured across five representative normal shock waves of N2 generated in a free jet, spanning the Mach number range 7.7<M<15.3. The interconversion of three differentiated populations (cold, scattered, and rethermalized molecules) across these shock waves shows a largely bimodal rotational distribution function with additional contribution of scattered molecules, in close analogy with the velocity distribution function known from helium shock waves [G. Pham-Van-Diep et al., Science 245, 624 (1989)]. Quantitative data on invariance trends of density profiles and properties of the wake beyond the shock waves are reported.

Circulating HER2 extracellular domain and resistance to chemotherapy in advanced breast cancer

To test the hypothesis of an association between HER2 and chemotherapy resistance, we performed a prospective assessment of the predictive value of the circulating HER2 extracellular domain (ECD) in patients with advanced breast carcinoma in the setting of a multicenter Phase II trial using paclitaxel and doxorubicin. Serum samples were collected from 58 patients with metastatic breast carcinoma before first-line chemotherapy for advanced disease, and the levels of circulating HER2 ECD were measured using an enzyme immunoassay. Immunohistochemistry with anti-HER2 monoclonal antibody CB11 was used to assess the overexpression of HER2 in the primary tumors. When 450 fmol/ml was used as a cutoff, 24 cases (41%) had elevated HER2 ECD levels. Elevated levels of circulating HER2 ECD were associated with the expression of HER2 in the primary tumor tissue and with the metastatic tumor burden (evaluated with the marker CA 15-3; P = 0.032 and P = 0.002, respectively) but not with variables such as menopausal status, stage at diagnosis, previous adjuvant therapy, or the number of metastatic sites. The levels of circulating HER2 ECD correlated inversely with the response to treatment. The probability of obtaining a complete response to chemotherapy was significantly lower (P = 0.021) in patients with elevated HER2 ECD levels (0%; 95% confidence interval, 0-13%) compared with patients with nonelevated HER2 (26%; 95% confidence interval, 12-45%). In addition, the duration of clinical response was significantly shorter in patients with elevated HER2 ECD, compared with the cases with nonelevated HER2 (7.5 versus 11 months; P = 0.035). In conclusion, elevated levels of circulating HER2 ECD in patients with metastatic breast cancer correlate with reduced efficacy of a paclitaxel-doxorubicin chemotherapy combination. We suggest that the poor response rate associated with HER2 expression in advanced breast cancer may not be reversed by aggressive chemotherapy alone.

Ro-vibrational Raman Cross Sections of Water Vapor in the OH Stretching Region

The Raman spectrum of H2O, in the gas phase at 26 mbar and 295 K, has been recorded from 3400 to 4130 cm-1 using an improved spectrometer of very high sensitivity. This spectrum is analyzed in terms of the wavefunctions and energy levels of Flaud and Camy-Peyret [J. Mol. Spectrosc. 51, 142 (1974)], and of the polarizability derivatives with respect to the dimensionless normal coordinates q1 and q3. It is shown that the anharmonic coupling between the vibrational states nu1 and nu3 has to be considered for a correct simulation of the observed spectrum. Tables with scattering strengths and energies of ro-vibrational transitions are provided in order to simulate the Raman spectrum of water vapor over a broad range of temperatures, from few Kelvin, under supersonic expansions, to high temperature, in combustion processes. Copyright 1999 Academic Press.

Angiogenin expression and prognosis in primary breast carcinoma

Angiogenin is a protein originally isolated as an inducer of new blood vessel growth, and it has been reported to be an effective substrate for tumor cell adhesion. To understand the role of angiogenin in cancer progression, we evaluated the expression of angiogenin in 459 cases with primary breast carcinoma and in 40 benign breast specimens using an immunoassay. Higher angiogenin concentrations were observed in carcinomas in comparison with fibrocystic disease (mean, 17.3 versus 10.9 ng/mg; P = 0.008), but not with fibroadenomas. We selected 5 ng/mg cytosol protein of angiogenin as the normal cutoff for primary breast carcinoma. Eighty-eight percent of carcinomas expressed elevated angiogenin levels and 12% had low levels. We observed an association between elevated levels of angiogenin and low/ moderate histological grade (P = 0.001) and small tumor size (P = 0.026), but not with age, menopausal status, lymph node status, stage of disease, or hormonal receptor status. With a median follow-up of 31 months, breast cancer patients with elevated angiogenin levels had significantly longer disease-free survival (DFS) than patients with low angiogenin (log-rank, P = 0.003). This effect was equally observed in node-negative and node-positive cases. In a multivariate analysis of DFS, only angiogenin, tumor size, and histological grade showed statistical significance. A multivariate analysis of overall survival showed that angiogenin and tumor size were the only significant variables. Serum samples from the breast cancer patients at the time of surgery were available in 194 cases. We evaluated the levels of circulating angiogenin using the same immunoassay as in tumor tissue. Serum angiogenin levels were higher in cancer patients than in 40 healthy controls (mean, 401.2 versus 206.0 ng/ml; P < 0.0001). In breast cancer patients, we observed no correlation between the serum concentrations and the tissue levels of angiogenin (r = 0.115; P = 0.110). In addition, serum levels of angiogenin did not have a prognostic impact on the DFS of breast cancer patients (log-rank, P = 0.581). Our results indicate that elevated levels of tissue angiogenin, but not of circulating angiogenin, are a favorable prognostic factor in primary breast carcinoma, which is consistent with a role of angiogenin as a cancer cell substrate.

Cytogenetic studies in seventy-six cases of B-chronic lymphoproliferative disorders

The results of cytogenetic studies are reported in 76 patients with B-chronic lymphoproliferative disorders (B-CLPD): 60 patients with chronic lymphocytic leukemia (CLL), six with follicular lymphoma in leukemic phase (FLLP), five with splenic B-cell lymphoma with villous lymphocytes (SLVL), two with chronic prolymphocytic leukemia (CPL), two with hairy cell leukemia (HCL), and one with plasma cell leukemia (PCL). PHA (phytohemagglutinin), PWM (pokeweed mitogen), LPS (lipopolysaccharide from Escherichia Coli), TPA (phorbol 12-myristate acetate), IL6 (interleukin 6), and DxS (dextran sulfate) were used as mitogens. Mitoses were obtained in 75 cases. Clonal aberrations could be demonstrated in 34 cases (44%). In CLL, classical type, chromosomes 6, 11, and 13 were more frequently involved, whereas trisomy 12 was frequently found in CLL mixed-cell type, in FLLP, and CPL. In SLVL the deletion del(7)(q32) is noteworthy and miscellaneous chromosome abnormalities in the remaining patients were observed. Regarding the efficiency of mitogens, PHA turned to be the most effective in obtaining metaphases and in detecting clonal chromosomal aberrations.

Low levels of basic fibroblast growth factor (bFGF) are associated with a poor prognosis in human breast carcinoma

It has been suggested that angiogenesis and angiogenic factors may be strong predictors of relapse in patients with breast carcinoma. We measured the levels of the angiogenic peptide basic fibroblast growth factor (bFGF) in 140 breast tumour cytosols using an immunoassay. There were no significant differences in bFGF levels between breast non-malignant lesions and primary carcinomas. In 124 cases with primary breast cancer, we observed an association of low bFGF levels (< 400 pg mg[-1]) with increasing tumour size (P = 0.023) and stage of disease (P = 0.002). bFGF levels did not correlate with other variables, including axillary nodes, hormone receptors, cathepsin D and the serum tumour markers CA15.3 and CEA. With a median follow-up of 44.0 months, breast cancer patients with low levels of bFGF had a significantly shorter disease-free survival (DFS) than patients with elevated bFGF (log-rank, P < 0.0001). In a multivariate analysis of DFS, only bFGF, T-stage and histological grade showed statistical significance. In a parallel evaluation of circulating bFGF, we did not observe a correlation between the serum and tissue bFGF levels in the 29 selected cases with matched determinations. Our results indicate that low bFGF levels in breast carcinoma are an independent prognostic indicator of poor prognosis and disease recurrence.

Immobilization of Candida rugosa lipase and some properties of the immobilized enzyme

Lipase (triacylglycerol ester hydrolase, E.C.3.1.1.3) from Candida rugosa has been immobilized on commercially available microporous polypropylene. The enzyme was rapidly adsorbed on the support, and more than 60% of the soluble activity disappeared from the medium after 1 min of incubation at room temperature. A recovery of immobilized activity of 21% was obtained when the wet preparation was immediately assayed with olive oil at the end of the immobilization protocol. The activity of the immobilized enzyme drastically decreased with the loss of water of the preparation. Pretreatment of the support with organic solvents significantly increased the recovered immobilized activity. Our results strongly suggest that the soluble lipase could exist in different aggregation forms depending on the pH of the medium. At acidic pH, the relative proportion of high-molecular-weight forms of the enzyme is higher than at pH 7.0, suggesting that the lipase would be also immobilized in different aggregation forms depending on the pH used in the immobilization procedure. Crosslinking of the adsorbed enzyme with glutaraldehyde diminished its activity but increased the stability of the lipase against the washing-out effect of Triton X-100. Data on the most relevant catalytic properties of the soluble and immobilized enzyme, such as optimum pH and temperature as well as ranges of stability, kinetic parameters, and activation energy for the hydrolysis of olive oil and p-nitrophenyl acetate, are reported.

A new chromosomal anomaly associated with mature B-cell chronic lymphoproliferative disorders: del(7)(q32)

Among 63 patients with chronic lymphoproliferative disorders (CLPD) studied cytogenetically in our laboratory, four showed a del(7)(q32); in two it was the sole cytogenetic anomaly and in two it was part of a complex karyotype. We suggest that despite the rarity of this anomaly, it could be related to CLPD.

Preproenkephalin RNA increases in the hypothalamus of rats stressed by social deprivation

1. Pharmacological evidence indicates that stress induced by brief (14 to 20-day) social deprivation in the rat is associated with an activation of the central preproenkephalin (ENK) opioid system. This study examines the neurochemical evidence that substantiates such an activation. 2. Using a specific ENK complementary DNA probe, ENK RNA levels were measured by dot blot and Northern blot analyses in different brain areas of socially deprived rats. Immunoreactivity to met-enkephalin-derived peptides was also evaluated by radioimmunoassay in the same brain regions. 3. Brief social deprivation increased the levels of ENK RNA and enkephalin immunoreactivity in whole hypothalamus. 4. Our data suggest that this type of stress appears to be associated to an induction of ENK gene transcription in hypothalamus.

New chromosomal abnormality. t(1;19;?) in a case of B-chronic lymphocytic leukemia

Cytogenetic analysis was performed on peripheral blood cells stimulated with interleukin 6 (IL-6), lipopolysaccharide from Escherichia coli (LPS), phytohemagglutinin (PHA), pokeweed mitogen (PWM) and tetradecanoyl-phorbol-acetate (TPA), in a patient with B-chronic lymphocytic leukemia, showing a t(1;19;?) translocation as the sole abnormality. To our knowledge, this translocation has not been described before in any human neoplasia. In this case, the poor response to therapy (survival time 4 months) suggested that t(1;19;?) could be related to an aggressive course of the disease.