Serum Neopterin Levels in Lung and Breast Cancer Patients Undergoing Radiotherapy And/Or Chemotherapy

The elevated neopterin levels observed in numerous haemotological diseases and parenchymatous malignomas suggested neopter in might be useful as a tumor marker. In a group of 60 patients suffering from advanced lung (18) or breast (42) cancer, serial determinations of serum neopterin were made before, during and after radiation and/or chemotherapy, during an observation period of 18 months, to check the potential value of neopterin in the therapeutic management of these tumor types. The neopterin profiles were compared with the clinical course and analysed with regard to response to therapy. Numbers of pathologically elevated serum neopterin levels were low. In only few cases was any agreement detected between changes in neopterin levels and therapeutic effects. Even chemotherapeutically induced depression in white blood counts generally did not increase serum neopterin levels. Thus the clinical suitability of neopterin as an adjuvant parameter in assessing therapeutic effects in lung or breast cancer could not be documented. (Int J. Biol Markers 1988; 3: 135-139)

Effect of Dialyzer Membranes on in Vitro Generation of Eicosanoids

Eicosanoids are potent substances released from blood cells after contact with foreign materials. Eicosanoid generation, in addition to complement fragment formation, may be a valuable indicator of the biocompatibility of dialyzer membranes. In the present in vitro study, eicosanoid generation induced by several different flat dialyzer membranes [polyacrylonitrile (PAN), cuprammonium cellulose (CC), and polycarbonate (PC)] was evaluated and compared using blood from non-uremic healthy volunteers.

Generation of prostaglandin E2 (PGE2) and thromboxane B2 (TXB2) was greatest with PC followed by PAN and CC. The formation of C3a des arg with PAN was less than with either CC or PC.

Our results suggest that dialyzer membranes affect complement activation and eicosanoid generation differently; biocompatibility as expressed by a low level of complement fragment formation does not necessarily translate into biocompatibility when considering eicosanoid generation.

Electronic structure and excited state dynamics in a dicyanovinyl-substituted oligothiophene on Au(111)

Dicyanovinyl (DCV)-substituted oligothiophenes are promising donor materials in vacuum-processed small-molecule organic solar cells. Here, we studied the structural and the electronic properties of DCV-dimethyl-pentathiophene (DCV5T-Me2) adsorbed on Au(111) from submonolayer to multilayer coverages. Using a multi-technique experimental approach (low-temperature scanning tunneling microscopy/spectroscopy (STM/STS), atomic force microscopy (AFM), and two-photon photoemission (2PPE) spectroscopy), we determined the energetic position of several affinity levels as well as ionization potentials originating from the lowest unoccupied molecular orbitals (LUMO) and the highest occupied molecular orbitals (HOMO), evidencing a transport gap of 1.4 eV. Proof of an excitonic state was found to be a spectroscopic feature located at 0.6 eV below the LUMO affinity level. With increasing coverage photoemission from excitonic states gains importance. We were able to track the dynamics of several electronically excited states of multilayers by means of femtosecond time-resolved 2PPE. We resolved an intriguing relaxation dynamics involving four processes, ranging from sub-picosecond (ps) to several hundred ps time spans. These show a tendency to increase with increasing coverage. The present study provides important parameters such as energetic positions of transport levels as well as lifetimes of electronically excited states, which are essential for designing organic-molecule-based optoelectronic devices.

Orbital redistribution in molecular nanostructures mediated by metal-organic bonds

Dicyanovinyl-quinquethiophene (DCV5T-Me2) is a prototype conjugated oligomer for highly efficient organic solar cells. This class of oligothiophenes are built up by an electron-rich donor (D) backbone and terminal electron-deficient acceptor (A) moieties. Here, we investigated its structural and electronic properties when it is adsorbed on a Au(111) surface using low temperature scanning tunneling microscopy/spectroscopy (STM/STS) and atomic force microscopy (AFM). We find that DCV5T-Me2 self-assembles in extended chains, stabilized by intercalated Au atoms. The effect of metal-ligand hybridization with Au adatoms causes an energetic downshift of the DCV5T-Me2 lowest unoccupied molecular orbital (LUMO) with respect to the uncoordinated molecules on the surface. The asymmetric coordination of a gold atom to only one molecular end group leads to an asymmetric localization of the LUMO and LUMO+1 states at opposite sides. Using model density functional theory (DFT) calculations, we explain such orbital reshaping as a consequence of linear combinations of the original LUMO and LUMO+1 orbitals, mixed by the attachment of a bridging Au adatom. Our study shows that the alignment of molecular orbitals and their distribution within individual molecules can be modified by contacting them to metal atoms in specific sites.

Optimization of solution-processed oligothiophene:fullerene based organic solar cells by using solvent additives

The optimization of solution-processed organic bulk-heterojunction solar cells with the acceptor-substituted quinquethiophene DCV5T-Bu 4 as donor in conjunction with PC61BM as acceptor is described. Power conversion efficiencies up to 3.0% and external quantum efficiencies up to 40% were obtained through the use of 1-chloronaphthalene as solvent additive in the fabrication of the photovoltaic devices. Furthermore, atomic force microscopy investigations of the photoactive layer gave insight into the distribution of donor and acceptor within the blend. The unique combination of solubility and thermal stability of DCV5T-Bu 4 also allows for fabrication of organic solar cells by vacuum deposition. Thus, we were able to perform a rare comparison of the device characteristics of the solution-processed DCV5T-Bu 4 :PC61BM solar cell with its vacuum-processed DCV5T-Bu 4 :C60 counterpart. Interestingly in this case, the efficiencies of the small-molecule organic solar cells prepared by using solution techniques are approaching those fabricated by using vacuum technology. This result is significant as vacuum-processed devices typically display much better performances in photovoltaic cells.

Interrelation between crystal packing and small-molecule organic solar cell performance

X-ray investigations on single crystals of a series of terminally dicyanovinyl-substituted quaterthiophenes and co-evaporated blend layers with C(60) give insight into molecular packing behavior and morphology, which are crucial parameters in the field of organic electronics. Structural characteristics on various levels and length scales are correlated with the photovoltaic performance of bulk heterojunction small-molecule organic solar cells.

Evidence for an additional effect of whole-body vibration above resistive exercise alone in preventing bone loss during prolonged bed rest

SUMMARY

The addition of whole-body vibration to high-load resistive exercise may provide a better stimulus for the reduction of bone loss during prolonged bed rest (spaceflight simulation) than high-load resistive exercise alone.

INTRODUCTION

Prior work suggests that the addition of whole-body vibration to high-load resistive exercise (RVE) may be more effective in preventing bone loss in spaceflight and its simulation (bed rest) than resistive exercise alone (RE), though this hypothesis has not been tested in humans.

METHODS

Twenty-four male subjects as part of the 2nd Berlin Bed Rest Study performed RVE (n = 7), RE (n = 8) or no exercise (control, n = 9) during 60-day head-down tilt bed rest. Whole-body, spine and total hip dual X-ray absorptiometry (DXA) measurements as well as peripheral quantitative computed tomography measurements of the tibia were conducted during bed rest and up to 90 days afterwards.

RESULTS

A better retention of bone mass in RVE than RE was seen at the tibial diaphysis and proximal femur (p ≤ 0.024). Compared to control, RVE retained bone mass at the distal tibia and DXA leg sub-region (p ≤ 0.020), but with no significant difference to RE (p ≥ 0.10). RE impacted significantly (p = 0.038) on DXA leg sub-region bone mass only. Calf muscle size was impacted similarly by both RVE and RE. On lumbar spine DXA, whole-body DXA and calcium excretion measures, few differences between the groups were observed.

CONCLUSIONS

Whilst further countermeasure optimisation is required, the results provide evidence that (1) combining whole-body vibration and high-load resistance exercise may be more efficient than high-load resistive exercise alone in preventing bone loss at some skeletal sites during and after prolonged bed rest and (2) the effects of exercise during bed rest impact upon bone recovery up to 3 months afterwards.

In vitro investigation of titanium and hydroxyapatite dental implant surfaces using a rat bone marrow stromal cell culture system

In this study, rat bone marrow cells (RBM) were used to evaluate different titanium and hydroxyapatite dental implant surfaces. The implant surfaces investigated were: a titanium surface having a porous titanium plasma-sprayed coating (sample code Ti-TPS), a titanium surface with a deep profile structure (sample code Ti-DPS), an uncoated titanium substrate with a machined surface (sample code Ti-ma) and a machined titanium substrate with a porous hydroxyapatite plasma-sprayed coating (sample code Ti-HA). RBM cells were cultured on the disc-shaped test substrates for 14 days. The culture medium was changed daily and examined for calcium and phosphate concentrations. After 14 days specimens were examined by light microscopy, scanning electron microscopy, energy dispersive X-ray analysis and morphometry of the cell-covered substrate surface. All test substrates facilitated RBM growth of extracellular matrix formation. Ti-DPS and Ti-TPS to the highest degree, followed by Ti-ma and Ti-HA. Ti-DPS and Ti-TPS displayed the highest cell density and thus seem to be well suited for the endosseous portion of dental implants. RBM cells cultured on Ti-HA showed a delayed growth pattern. This may be related to its high phosphate ion release.

Evaluation of calcium phosphates and experimental calcium phosphate bone cements using osteogenic cultures

In this study, rat bone marrow cells (RBM) were used to evaluate two biodegradable calcium phosphate bone cements and bioactive calcium phosphate ceramics. The substances investigated were: two novel calcium phosphate cements, Biocement F and Biocement H, tricalcium phosphate (TCP), surface-modified alpha-tricalcium phosphate [TCP (s)] and a rapid resorbable calcium phosphate ceramic consisting of CaKPO(4) (sample code R5). RBM cells were cultured on disc-shaped test substrates for 14 days. The culture medium was changed daily and also examined for calcium, phosphate, and potassium concentrations. Specimens were evaluated using light microscopy, and morphometry of the cell-covered substrate surface, scanning electron microscopy, and energy dispersive X-ray analysis and morphometry of the cell-covered substrate surface. Areas of mineralization were identified by tetracyline labeling. Except for R 5, rat bone-marrow cells attached and grew on all substrate surfaces. Of the different calcium phosphate materials tested, TCP and TCP (s) facilitated osteoblast growth and extracellular matrix elaboration to the highest degree, followed by Biocements H and F. The inhibition of cell growth encountered with R 5 seems to be related to its high phosphate and potassium ion release.

In vitro investigation of novel calcium phosphates using osteogenic cultures

A rat bone marrow stromal cell (RBM) culture was used to evaluate novel bioactive calcium phosphate ceramics. Three rapidly resorbable, glassy crystalline materials with the main crystalline phase Ca2KNa(PO4)2 were investigated (sample code GB 1a, GB 14, GB 9). These materials were designed to exhibit a higher degree of biodegradability than tricalcium phosphate. Additionally, a bioactive glass ceramic of low biodegradability was examined (sample code AP 40). RBM cells were cultured on the disc-shaped test substrata for 14 d. The culture medium was changed and calcium and phosphate concentrations of the medium were determined daily. Specimens were evaluated using light microscopy and morphometry of the cell-covered substrate surface, scanning electron microscopy and energy dispersive X-ray analysis. Except for GB 1a, the rat bone marrow cells attached and grew on all substrate surfaces. Of the different calcium phosphate ceramics tested, AP 40 facilitated osteoblast growth and the elaboration of the extracellular matrix to the highest degree followed by GB 9 and GB 14. The inhibition of cell growth encountered with GB 1a seemed to be related to its high phosphate ion release.

Serum cardiac troponin T as a prognostic marker in early sepsis

STUDY OBJECTIVE

Sepsis is the leading cause of death in the noncardiologic ICU. Maldistributed nutritive blood flow and altered convective and diffusive oxygen transport during sepsis can lead to organ dysfunction and multiple organ failure. One of the causes of myocardial dysfunction is thought to be myocardial ischemia in sepsis; however, conventional biochemical parameters to detect myocardial ischemia lack sensitivity and specificity. Serum cardiac troponin T (S-TnT) was reported to have higher sensitivity and specificity in diagnosing minor myocardial injury. The aim of this study was to investigate if and how often S-TnT is pathologically elevated in patients with sepsis and to evaluate whether S-TnT might be a prognostic marker in early sepsis.

DESIGN

Prospective study.

SETTING

Surgical ICU.

PATIENTS

Twenty-six patients with sepsis were included in this study within 24 h of the onset of sepsis. The patients were allocated a priori to a high S-TnT group (S-TnT > or = 0.2 microg/L) and a low S-TnT group (S-TnT<0.2 microg/L).

MEASUREMENT

Blood samples for the determination of S-TnT and conventional myocardial ischemia markers as well as for adhesion molecules were drawn. Hemodynamic measurements were performed every 4 h during the first 24 h and then once per day over 7 days. S-TnT was determined by enzyme-linked immunosorbent sandwich assay.

RESULTS

Eighteen patients had pathologically high S-TnT values. High S-TnT values were associated with an increased mortality rate (15/18 in the high S-TnT group vs 3/8 in the low S-TnT group; p=0.02). Significant differences between the two groups were found in the norepinephrine dosages at maximum values of S-TnT. Soluble intercellular adhesion molecule-1 was significantly elevated in the high S-TnT group.

CONCLUSIONS

As high S-TnT values were associated with an increased mortality rate, it seems reasonable to further evaluate S-TnT as a prognostic marker of myocardial ischemia in patients with sepsis under different therapeutic regimens.

Rapid analysis of O-acetylated neuraminic acids by matrix assisted laser desorption/ionization time-of-flight mass spectrometry

N-Acetylneuraminic acid (a sialic acid) occurs mainly as a terminal substituent of oligosaccharides of glycoconjugates. Derivatives of neuraminic acid occur widely, substituted in the amino and hydroxy side chains, as well in the C-9 carbon skeleton. These derivatives are responsible for specific functions of sialic acids during cell-cell, cell-substrate, or cell-virus interactions. The study of O-acetylated neuraminic acids is difficult, because only small amounts are extractable from natural sources and they are generally unstable to acids and bases. We report a new method for the rapid analysis of O-acetylated neuraminic acids, using a combination of reversed phase HPLC and MALDI-TOF mass spectrometry. A mixture of neuraminic acids from bovine submaxillary gland mucins was analysed, as well as neuraminic acids variously substituted in the amino and hydroxy side chains with acetyl and glycolyl groups, respectively.

Morphological evaluation of osteoblasts cultured on different calcium phosphate ceramics

The objective of these investigations was to develop an in vitro test system for evaluating novel rapidly resorbable calcium phosphate ceramics of varying composition. Rat bone marrow cells were cultured on the disc-shaped test substrates for 14 days. Five calcium phosphates were examined: R1 CaNaPO4; R1/M2, composed of CaNaPO4 and MgNaPO4; R1/2, composed of CaNaPO4 and Mg2SiO4; R1 + 9% SiO2 consisting of CaNaPO4 and 9% SiO2 (wt%) and R17, Ca2KNa(PO4)2. Two studies were performed. In study I cultures were re-fed every two to three days. In study II the medium was changed daily, and calcium and phosphate concentrations of the medium were determined daily. Specimens were prepared for light microscopy and morphometric evaluation of the cell-covered substrate area, scanning electron microscopy and energy-dispersive X-ray analysis. With all materials tested except for R1/2, an increase of cellular growth was observed after changing the medium daily. Of the different calcium phosphate ceramics tested, R17 and R1/M2 facilitated osteoblast growth and elaboration of extracellular matrix to the highest degree. The inhibition of cell growth encountered with R1 in study I and R1/2 in both studies seemed to be related to a high phosphate-ion release from these materials.

Endogenous inhibitors of 11 beta-OHSD: existence and possible significance

Inhibition of 11 beta-hydroxysteroid dehydrogenase (11 beta-OHSD) by licorice-derived compounds and in cases of idiopathic impairment of this enzyme is known to result in hypermineralocorticoid syndromes, reflecting corticosteroid receptor activation by excess intracellular glucocorticoids. In this paper we address the question of whether or not endogenous inhibitors of 11 beta-OHSD exist that might cause pathological glucocorticoid metabolism. Using microsomal preparations we have demonstrated that bile acids are potent inhibitors of rat renal and human hepatic 11 beta-OHSD, with lithocholic acid exerting the strongest effect. The human renal enzyme is affected to a lesser extent. Serum of patients with cholestatic liver cirrhosis also inhibited 11 beta-OHSD activity, in parallel with total bile acid concentration. Cholesterol and its precursor lanosterol inhibited the enzymatic activity in microsomes from rat and human kidney cortex and human liver. We conclude that bile acids could contribute to the abnormalities of cortisol metabolism observed in cholestatic liver cirrhosis.

Serum neopterin levels in lung and breast cancer patients undergoing radiotherapy and/or chemotherapy

The elevated neopterin levels observed in numerous haemotological diseases and parenchymatous malignomas suggested neopterin might be useful as a tumor marker. In a group of 60 patients suffering from advanced lung (18) or breast (42) cancer, serial determinations of serum neopterin were made before, during and after radiation and/or chemotherapy, during an observation period of 18 months, to check the potential value of neopterin in the therapeutic management of these tumor types. The neopterin profiles were compared with the clinical course and analysed with regard to response to therapy. Numbers of pathologically elevated serum neopterin levels were low. In only few cases was any agreement detected between changes in neopterin levels and therapeutic effects. Even chemotherapeutically induced depression in white blood counts generally did not increase serum neopterin levels. Thus the clinical suitability of neopterin as an adjuvant parameter in assessing therapeutic effects in lung or breast cancer could not be documented.

[The effect of thoracic peridural analgesia on the cortisol and glucose response in surgery of the abdominal aorta]

It has been shown that the stress response to lower abdominal surgery can be inhibited by epidural analgesia (EA). But EA seems to have little influence on the stress reaction to major abdominal surgery. The purpose of our study was to find out whether EA is able to diminish the cortisol and glucose response to major transabdominal surgery.

METHODS

31 patients undergoing elective surgery of the abdominal aorta were subdivided at random into 3 different anaesthesia groups: 1. halothane anesthesia, 2. neuroleptanalgesia (NLA) and 3. thoracic EA with bupivacaine (0.5%) in combination with a light general anesthesia. Some patients of each group received an intravenous infusion of 5% glucose. Blood samples were drawn before anesthesia, after intubation, 5 times during surgery and at the end of the operation and were analysed for cortisol and glucose. During the early postoperative period, 1, 2 and 24 h after surgery, only cortisol was measured.

RESULTS

Only the glucose levels of patients who received no carbohydrate-containing infusion fluids were used for evaluation of the stress response. In the halothane group, there was a significant increase of the mean cortisol and glucose levels after the start of surgery. No intraoperative elevations of blood glucose and cortisol were seen in the EA group. Patients of the NLA group showed no hyperglycaemia and only mild elevations of the cortisol levels during the intraoperative period.(ABSTRACT TRUNCATED AT 250 WORDS)

Elevated tumor markers in hemodialysis patients

The incidence of elevated tumor markers without clinical signs of malignant disease was examined in 93 patients between the age of 29 and 79 years and on chronic dialysis for 3-240 months. Tissue polypeptide antigen was found to be elevated in 92.5%, carcinoembryonic antigen in 29.8, and alpha-fetoprotein in 6.5%. High levels of tissue polypeptide antigen were accompanied by high levels of beta 2-microglobulin (p less than 0.005). This indicates that tumor markers, and tissue polypeptide antigen in particular, may be unreliable for monitoring malignant disease in patients on hemodialysis.

Acute acid load in recurrent oxalate stone formers

An acute acid load was used to evaluate potential chemical differences of urinary composition in recurrent oxalate stone formers and healthy controls. After intake of ammonium chloride, total calcium, ionized calcium and magnesium increased and citrate decreased significantly in both groups. Differences between stone formers and controls could be demonstrated from the excretion of total calcium, citrate, oxalate and uric acid only after acute acid load, whereas ionized calcium did not improve discrimination. These findings support the stone-promoting role of high acid food as well as the possibility of discriminating recurrent oxalate stone formers from controls by an acute acid-loading test.

Effect of dialyzer membranes on in vitro generation of eicosanoids

Eicosanoids are potent substances released from blood cells after contact with foreign materials. Eicosanoid generation, in addition to complement fragment formation, may be a valuable indicator of the biocompatibility of dialyzer membranes. In the present in vitro study, eicosanoid generation induced by several different flat dialyzer membranes [polyacrylonitrile (PAN), cuprammonium cellulose (CC), and polycarbonate (PC)] was evaluated and compared using blood from non-uremic healthy volunteers. Generation of prostaglandin E2 (PGE2) and thromboxane B2 (TXB2) was greatest with PC followed by PAN and CC. The formation of C3a des arg with PAN was less than with either CC or PC. Our results suggest that dialyzer membranes affect complement activation and eicosanoid generation differently; biocompatibility as expressed by a low level of complement fragment formation does not necessarily translate into biocompatibility when considering eicosanoid generation.

[Examination of cardiac function following long-term tocolysis with fenoterol and isoxsuprine in newborn (author's transl)]

We can sum up as follows: In special cases, tocolytics can lead to complications in the mother as well as in the foetus. These may be partly so severe that lead to patient's death, as some case histories show. In the majority of cases, however, there are only slight transient changes which are no longer manifest after a few weeks' time. Hence, it should be mandatory to initiate special cardiologic supervision of the children during the perinatal period if administration of tocolytics was unavoidable for the purpose of maintaining the state of pregnancy. It would be optimal if these patients, besides being examined clinically, would also be examined via echocardiogram, electrocardiogram and CK-MB determination. Since the echocardiographic examination, in particular, entails a great deal of expenditure of time and requires a relatively complicated instrumental set-up, we believe that recording the ecg and CK-MB should suffice, as practicable examination parameters in clinical routine, to detect this damage of the myocardium well in time.