Quantification of mechanical properties in long-term in vivo used silicone catheter lines according to DIN 10555-3

BACKGROUND

Totally implantable central venous access port devices are crucial for intravenous application of chemotherapeutics and long-term therapy for chronic disease. Common complications include thrombosis and device fracture related to altered material properties through exposure in situ. This study exhibits whether uniaxial tensile properties (DIN 10555-3) of in vivo used catheters prove inferior to unused catheters.

MATERIAL AND METHODS

5 unused, originally packed silicone catheters were cut into 6 segments of 50 mm: 3 segments each were cleaned via cleaning solution (n = 15) while 3 segments were left unattended (n = 15). Distal segments (50 mm) of long-term in vivo used silicone catheters were cleaned before testing (n = 33). Overall mechanical behavior was tested in a custom-made self-centering, torsion free carrier. Maximum force stress at failure, strain at failure and Young's modulus were determined and statistically analyzed.

FINDINGS

Unused catheters showed no significant difference in testing. in vivo used catheters exhibited 20% lower maximal force than unused catheters (p < 0.001), strain at break (p 〈0,001), and 7% higher elastic modulus (p = 0.004; power: 0.845). Due to a constant cross section area, stress at failure was proportional to maximum force (p < 0.001). Relation between determined parameters and dwell times was non-significant.

INTERPRETATION

In vivo long-term used silicone catheters showed significantly lower ultimate strength than unused ones. It is likely that in situ altering changes the mechanical properties of catheters and may potentially lead to failure.

Obstacles to HBV functional cure: Late presentation in HIV and its impact on HBV seroconversion in HIV/HBV coinfection

Several cohorts have shown that long-term tenofovir-containing combination antiretroviral therapy (cART) leads to higher HBsAg seroclearance rates in HIV/HBV coinfected patients vs HBV-monoinfected patients under tenofovir disoproxil fumarate (TDF)-based therapy. We have analysed data on determinants of HBsAg loss in a retrospective multicentric cohort of 359 HIV/HBV coinfected patients. Median CD4 T-cell count at baseline was 359/ul (321-404), CDC stage was C in 20% (n = 70). Most patients (68%) were ART-naïve when TDF- or tenofovir alafenamide (TAF)-containing cART was initiated (baseline). After a median follow-up of 11 years HBsAg loss had occurred in 66/359 (18%) patients. However, patients with stage CDC C (P ≤ .001), lower CD4 gain (P = .043) and not receiving TDF/FTC (P = .008) were less likely to lose HBsAg. Long-term TDF-containing cART appears to achieve higher rates of HBsAg seroclearance compared to published data for HBV monoinfected subjects. However, late presentation for HIV and poor immune recovery significantly impair HBV seroconversion rates.

A NEW TL-DOS NEUTRON DOSEMETER FOR MEASUREMENTS OF THE PERSONAL DOSE EQUIVALENT HP(10)

A new thermoluminescence albedo dosemeter with improved properties is developed as part of the TL-DOS project. The dosemeter measures the neutron and photon whole-body dose of radiation workers. The TL-DOS neutron dosemeter is presented and its results of well-known field measurements as well as field calibrations are shown. Its advantages, such as its potential to measure the high-linear energy transfer peaks, its improved detector sensitivity and long detector lifetime, are explained. The new dosemeter is compared to a thermoluminescence albedo dosemeter already used in routine dosimetry in Germany.

INTERCOMPARISON OF EYE LENS DOSEMETERS

An intercomparison of eye lens dosemeters has been conducted in terms of the quantity Hp(3). For the first time, besides photon radiation also beta radiation qualities were included. Three dosemeter types designed for the quantity Hp(3) and ten for Hp(0.07) took part in the intercomparison. As shown in a previous intercomparison for photon radiation only, the dosemeters designed for Hp(0.07) and calibrated in terms of Hp(3) performed well in photon radiation fields. But for beta radiation, it turned out that Hp(0.07) dosemeters over-responded up to a factor of 5 000 (with respect to the true Hp(3) dose) in the medium beta energy range (85Kr with a beta endpoint energy of 0.69 MeV), while some Hp(3) dosemeters performed quite well. For medium (57 keV) and high (662 keV) energy photon radiation, all dosemeter types showed response values well within the trumpet curve according to the current draft of ISO 14146.

Control of bovine tuberculosis in a farmed red deer herd in England

This report describes how Mycobacterium bovis infection was controlled and eventually eradicated in a farmed red deer herd in the north of England, following sustained tuberculin skin testing supplemented with serological (antibody) tests over a period of approximately two years. By taking advantage of the anamnestic antibody response produced by the skin test to detect skin test-negative, antibody-positive infected individuals, a total of 35 additional animals were identified, including 2 with gross visible lesions typical of bovine tuberculosis (BTB). Without detection and removal, these animals would have posed a continued risk of BTB persistence within the herd and potentially contributed to the spread of infection from deer into wildlife and surrounding cattle farms in an area of low BTB incidence. This case supports the use of ancillary diagnostic serological tests to speed up the resolution of incidents of BTB caused by M bovis in captive deer herds.

A THIN-LAYER LIF THERMOLUMINESCENCE DOSEMETER SYSTEM WITH FAST READOUT FOR THE USE IN PERSONAL DOSIMETRY SERVICES

A newly developed thermoluminescence dosemeter system is presented that is suitable for application in fields where personal monitoring of a large number of users is required. The system presented here is intended to be used as the upcoming main dosemeter for whole body dosimetry at the dosimetry service of the MPA NRW (Germany) with ∼110,000 evaluations per month.

Outcome After Thrombectomy and Intravenous Thrombolysis in Patients With Acute Ischemic Stroke

Background and Purpose—

In patients with ischemic stroke, randomized trials showed a better functional outcome after endovascular therapy with new-generation thrombectomy devices compared with medical treatment, including intravenous thrombolysis. However, effects on mortality and the generalizability of results to routine clinical practice are uncertain.

Methods—

In a prospective observational register-based study patients with ischemic stroke treated either with thrombectomy, intravenous thrombolysis, or their combination were included. Primary outcome was the modified Rankin scale score (0 [no symptoms] to 6 [death]) at 3 months. Ordinal logistic regression was used to estimate the common odds ratio as treatment effects (shift analysis). Propensity score matching was applied to compare patients treated either with intravenous thrombolysis alone or with intravenous thrombolysis plus thrombectomy.

Results—

Among 2650 recruited patients, 1543 received intravenous thrombolysis, 504 underwent thrombectomy, and 603 received intravenous thrombolysis in combination with thrombectomy. Later time-to-treatment was associated with worse outcomes among patients treated with thrombectomy plus thrombolysis. In 241 pairs of propensity score–matched patients with a proximal intracranial occlusion, thrombectomy plus thrombolysis was associated with improved functional outcome (common odds ratio, 1.84; 95% confidence interval, 1.32–2.57), and reduced mortality (15% versus 33%; P <0.0001) compared with intravenous thrombolysis alone. Results were similar in various sensitivity analyses accounting for missing outcome data and different analytic methods.

Conclusions—

Results from this large prospective registry show that also in routine clinical care thrombectomy plus thrombolysis compared with thrombolysis alone improved functional outcome and reduced mortality in patients with ischemic stroke. Earlier treatment was associated with better outcomes.

Semiempirical QM/MM calculations reveal a step-wise proton transfer and an unusual thiolate pocket in the mechanism of the unique arylpropionate racemase AMDase G74C

Semiempirical calculations on the mechanism of the arylpropionate racemase AMDase G74C reveal a step-wise mechanism involving a planar-enedionate intermediate.

Development and evaluation of a non-peptidic ligand for the molecular imaging of inflammatory processes using S100A9 (MRP14) as a novel target

We describe the development and first evaluation of a novel S100A9 specific molecular imaging probe (Cy5.5-CES271) for optical imaging of local inflammatory activity in vivo.

Albedo neutron dosimetry in Germany: regulations and performance

Personal neutron dosimetry has been performed in Germany using albedo dosemeters for >20 y. This paper describes the main principles, the national standards, regulations and recommendations, the quality management and the overall performance, giving some examples.

A whole-body dosimetry system for personal monitoring based on hot-pressed thin layer TLD

We are introducing a new high-capacity thermoluminescent dosemeter (TLD) system to measure the whole body values of H(p)(10) and H(p)(0.07) from photons for use in individual monitoring services. Small and light-weight badges allow a convenient application in a wide variety of workplaces with photon radiation from 20 keV to at least 7 MeV. The main advantage of this system will be the large capacity of ∼ 100,000 dosemeters per month at costs equivalent to the current film monitoring. The hot-pressed thin-layer TL detector (LiF:Mg,Ti) is welded onto an aluminium substrate and provided with a data matrix code for automatic processing. The detector holder has been optimised, that no additional filter is necessary. The new designed TLD reader with readout times <10 s will allow a large throughput and a considerable degree of automation.

A pilot open trial of brief psychodynamic psychotherapy for panic disorder

This is a complete report of an open trial of manualized psychodynamic psychotherapy for treatment of panic disorder, Panic-Focused Psychodynamic Psychotherapy (PFPP). Twenty-one patients with PD were entered into a trial of twice-weekly, 24-session treatment. Sixteen of 21 experienced remission of panic and agoraphobia. Treatment completers with depression also experienced remission of depression. Improvements in symptoms and in quality of life were substantial and consistent across all measured areas. Symptomatic gains were maintained over 6 months. This report was prepared specifically to describe 6-month follow-up on these patients. Psychodynamic psychotherapy appears to be a promising nonpharmacological treatment for panic disorder.

Open trial of psychodynamic psychotherapy for panic disorder: a pilot study

OBJECTIVE

This report contains preliminary data from an open trial of brief psychodynamic psychotherapy for panic disorder.

METHOD

Fourteen patients with primary DSM-IV panic disorder completed a 24-session, twice-weekly course of psychodynamic psychotherapy. Other psychiatric treatment was not permitted throughout the 12-week treatment period and the 6-month follow-up. Symptoms were assessed at baseline, treatment termination, and 6-month posttermination follow-up (40 weeks).

RESULTS

Statistically significant, clinically meaningful improvements appeared in panic, depression, anxiety, and functional impairment both at treatment termination and at 6-month follow-up.

CONCLUSIONS

Psychodynamic monotherapy can be used successfully to retain and treat patients with panic disorder. Psychodynamic interventions warrant further study for patients with panic disorder.

What is a deep interpretation?

Important differences are emerging regarding the place where analysts believe the most meaningful analytic work takes place. One area that highlights these distinct ways of working is the analyst's view of deep interpretations. Models underlying the differing perspectives on this issue are presented, along with an extended clinical example that illustrates the importance of considering, in formulating analytic interventions, the concept of a structured mind. A view of the analytic process that accords the patient's perspective greater privilege is introduced.

X-ray microtomography (microCT) using phase contrast for the investigation of organic matter

PURPOSE

We show that microtomography (microCT) using synchrotron radiation (SR) can be extended to include X-ray phase contrast, which is two to three orders of magnitude more sensitive than conventional attenuation contrast and better suited for the investigation of specimens consisting chiefly of light elements for photon energies ranging at least from 1 to 100 keV.

METHOD

Phase contrast is generated by placing the specimen in one of the interfering beams of an X-ray interferometer. With use of 12-keV X-rays, phase projections of the specimen are recorded at 180 or 360 angular settings equally spaced between 0 and 180 degrees. One phase projection consists of four pairs of "associated" radiograms in the sense that one is taken with and the other without the specimen in the beam. Between pairs a parallel-sided phase-shifter plate is rotated for changing the relative phase of the two interfering beams by multiples of pi/2 rad. By calculating phase-weighted sums of all associated pairs of radiograms, true phase-shift projections are obtained for all angular settings of the specimen, which are then reconstructed.

RESULTS

Three-dimensional images have been obtained from rat cerebrum and rat trigeminal nerve, showing cell structures at 8- to 15-micron spatial resolution. Gray and white matter of cerebrum and neurons in the trigeminal nerve are clearly visible.

CONCLUSION

X-ray phase-contrast microCT is becoming a valuable tool for studies of organic samples in medicine and biology.

Preclinical and clinical studies of a collagen membrane (Bio-Gide)

Membranes are used to guide the repopulation of defects by preferred cells and to achieve a specific healing effect. The collagen membrane studied, Bio-Gide, was developed particularly for periodontal, peri-implant applications or to improve the ossification of bone defects of any origin. Bio-Gide is a bilayer membrane; one compact and smooth layer is covered by a particularly dense film, designed to prevent the invasion of soft tissue in a membrane-protected bone defect. The other, rough side of Bio-Gide must be placed towards the bone defect in order to make bone ingrowth possible. As a prerequisite for its therapeutic use in humans, the collagen matrix must be devoid of major immunogenicity. The immunological response to the membrane material was analysed in rabbits. Later, a clinical prospective study provided information about the bone regeneration effect under the Bio-Gide membrane inserted in six patients selected at random. The immune response to the collagen membrane Bio-Gide and the bone healing was tested in these patients when undergoing oral surgery.

Understanding the patient's use of the method of free association: an ego psychological approach

While most of our methods of listening have been geared toward unearthing unconscious fantasies, those directed toward the ego's all-inclusive role in effecting the associative process have lagged far behind. It is the thesis of this paper that listening from the perspective of the ego allows the analyst to work more closely with what the patient is ready to understand. Clinical technique, using an ego psychological view, is elaborated, demonstrated, and compared to technique dependent on the reading of signs and symbols of the unconscious.

Long-term outcome of panic disorder treatment. A review of the literature

This review was designed to provide a detailed analysis of long-term outcome data from treatment studies for panic disorder, with the goal of ascertaining differential efficacy of the available treatments. Studies were included if they were published after 1980 and if follow-up took place at least 6 months after treatment termination. Thirty-one studies were located. A variety of methodological problems were found in these studies, including lack of clarity of diagnosis, lack of clarity in the treatment administered, and inadequately tracked nonstudy treatments during the study and follow-up periods, which limited the information that could be obtained about long-term outcome. Long-term outcome studies that closely track the additional treatments that patients receive are necessary to draw more definitive conclusions about differential treatment efficacy for panic disorder. Available data suggest that there is limited evidence for long-term maintenance of short-term treatment gains in panic disorder patients in the absence of continued treatment.

The ego and its significance in analytic interventions

Freud's view of the ego as Januslike, the one component of the psychic system turned toward the external world yet partly unconscious, should have insured its centrality in clinical interventions. However, history and experience do not bear this out. It is argued that a core part of the change process in analysis lies in the modifications that occur in ego functioning, making it necessary to carefully consider the role of the ego in clinical technique. Numerous clinical examples are presented to show the manner and significance of such an approach.

[New possibilities for structural analysis of bone biopsies using microcomputer tomography (muCT)]

The combined histological and microcomputed analysis of human iliac crest biopsies leads to major advances in our understanding of three-dimensional bone architecture. Microcomputed tomography avoids the time-consuming reconstruction and artifacts of serial sections. Furthermore, its high resolution allows the recording of structural differences as low as 10 microns. Thus, three-dimensional analysis in combination with histological evaluation of cellular dynamics facilitates earlier and easier recording of changes of cancellous bone.

Selective downregulation of rat cardiac beta 1-adrenoceptors by cyclosporine A: prevention by diltiazem or angiotensin-converting enzyme inhibitors

OBJECTIVES

This study attempted to determine whether long-term treatment with cyclosporine A in rats affects cardiac beta 1-adrenoceptors and whether this can be prevented by angiotensin-converting enzyme inhibitors or calcium-entry blocking agents.

BACKGROUND

In the transplanted human heart the density of beta 1-adrenoceptors decreases with time after transplantation, whereas that of beta 2-adrenoceptors does not. Because heart transplant recipients are treated with cyclosporine A, we studied whether administration of cyclosporine A in rats might cause this beta 1-adrenoceptor downregulation.

METHODS

We performed two studies. First, we treated groups of 10 male normotensive Wistar rats orally with 30 mg/kg body weight per day of cyclosporine A, 10 mg/kg per day of enalapril and 60 mg/kg per day of diltiazem, alone or in combination, for 6 weeks each. Second, we treated groups of 15 male normotensive Wistar rats orally with 15 mg/kg per day of cyclosporine A and 10 mg/kg per day of lisinopril, alone or in combination, for 6 weeks each. At the end of each treatment regimen, cardiac beta-adrenoceptor density and subtype distribution were assessed by (-)-[125I]iodocyanopindolol binding.

RESULTS

Both doses of cyclosporine A caused a significant decrease in cardiac beta 1-adrenoceptor density without affecting beta 2-adrenoceptor density. Although diltiazem and the angiotensin-converting enzyme inhibitors alone did not affect cardiac beta-adrenoceptors, they prevented the cyclosporine A-induced downregulation of beta 1-adrenoceptors.

CONCLUSIONS

In normotensive Wistar rats, cyclosporine A causes a significant decrease in cardiac beta 1-adrenoceptors without affecting beta 2-adrenoceptors. This can be prevented by diltiazem or angiotensin-converting enzyme inhibitors. In heart transplant recipients, who undergo long-term treatment with cyclosporine A, there is a very similar beta 1-adrenoceptor down-regulation with time after transplantation. Thus, administration of cyclosporine A may cause these beta-adrenoceptor subtype alterations.

Beginning a psychoanalytic treatment: establishing an analytic frame

The opening phase of analysis has received scant attention. Freud initially included, as essential, the establishment of an analytic process via the method of free association in the opening phase. However, his stance in relation to this process we can now characterize as authoritarian, and as influenced by suggestion and manipulation. Recent literature, while contributing to the understanding of the range of dynamics possible when beginning an analysis, continues to ignore the manner in which the method of free association may be used by both participants in establishing an analytic frame. Two clinical examples of how this latter process may be inaugurated are given, and reasons for the drift away from it are suggested.

Do actions speak louder than words? A query into an enigma in analytic theory and technique

While action is increasingly viewed as ubiquitous throughout psychoanalytic treatment, our understanding of why it occurs is limited by rudimentary views of verbalization and action. Dynamic and genetic interpretations of action, usually given at a time of resistance impasse, give only a partial explanation of the phenomenon. The question is explored of why the behavior may appear in the form of action, as well as its implication for interpretive strategies. A major premise is that the role of the ego has been overlooked, especially modes of thinking associated with earlier developmental levels.

Local versus general anesthesia for Shouldice repair of the inguinal hernia

Since February 1992 local anesthesia (LA) has been used routinely for repair of inguinal hernias at our surgical department. All patients undergoing Shouldice repair of primary uncomplicated inguinal hernia between January 1990 and March 1993 were analyzed retrospectively concerning the need for analgesics, length of stay in hospital, and rate of complications. In addition 50 patients after LA and 50 patients after general anesthesia underwent prospective pain analysis using a visual analogous score and spirometric tests (FEV1 and peak flow). After LA we found less need of analgesics, shorter hospital stays, and fewer complications. The pain level was lower, and ventilatory function was less affected. Repair of the inguinal hernia using LA is a safe method to lower the risk of the operation and to improve the patient's comfort without increasing complications.

3D computed X-ray tomography of human cancellous bone at 8 microns spatial and 10(-4) energy resolution

Human cancellous bone was imaged and its absorptive density accurately measured in three dimensions (3D), nondestructively and at high spatial resolution by means of computerized microtomography (microCT). Essential for achieving the resolution and accuracy was the use of monoenergetic synchrotron radiation (SR) which avoided beam hardening effects, secured excellent contrast conditions including the option of energy-modulated contrast, and yet provided high intensity. To verify the resolution, we selected objects of approximately 8 micron size that could be observed on tomograms and correlated them in a unique manner to their counter images seen in histological sections prepared from the same specimen volume. Thus we have shown that the resolution expected from the voxel size of 8 microns used in the microCT process is in effect also attained in our results. In achieving the present results no X-ray-optical magnification was used. From microCT studies of composites (Bonse et al., X-ray tomographic microscopy (XTM) applied to carbon-fibre composites. In: Materlik G, ed. HASYLAB Jahresbericht 1990. Hamburg: DESY, 1990; 567-568) we know that by including X-ray magnification a resolution below 2 microns is obtained. Therefore, with foreseeable development of our microCT method, the 3D and nondestructive investigation of structures in mineralized bone on the 2 micron level is feasible. For example, it should be possible to study tomographically the 3D distribution and amount of osteoclastic resorption in the surrounding bone structure.

Some ambiguities in the method of free association and their implications for technique

The method of free association, rooted in the topographic model, has not been clearly defined in structural terms. Little changed since Freud; the method is geared toward overcoming rather than investigating resistances. Furthermore, it is designed to discourage rather than encourage self-analysis. This seems to be another example of a "developmental lag" in adapting the psychology of the ego to clinical technique.

[Inguinal hernia repair with local anesthesia--a comparative analysis]

Since February 1992 local anaesthesia has been routinely used for repair of inguinal hernias at the Surgical Department of the RWTU Aachen. All 607 patients undergoing Shouldice repair of primary inguinal hernia between January 1990 and March 1993 were retrospectively analysed with reference to need for analgesics, length of stay in hospital, and rate of complications. In addition, 50 patients treated with local anaesthesia and 50 patients treated under general anaesthesia underwent prospective pain analysis using a visual analogue scale and spirometric tests. Following local anaesthesia we found fewer need of analgesics, shorter stays in hospital, and less complications. The pain level was lower and ventilatory function was better. Repair of inguinal hernia with local anaesthesia is a safe method of lowering the risks involved in the operation and improving patient comfort without increasing complications.

"In the neighborhood": aspects of a good interpretation and a "developmental lag" in ego psychology

The significance of the conscious ego in the interpretive process has increasingly come under scrutiny. It is becoming clearer that the analyst's view of the conscious ego orients his interpretive approach, and subtly sets the goals of the analysis. At various times Freud championed the analytic importance of the conscious ego, and alternately rejected its significance. Hartmann's view of the ego stimulated research into a developmental line of the ego, while investigations of the ego in clinical psychoanalysis lagged far behind. The importance of the conscious ego in understanding resistances and levels of communication are explored.

Recurring thoughts on unconscious ego resistances

Analysis of the unconscious ego resistances is one of those clinical concepts more honored in the breach than in the observance. This same point has been made periodically over the past fifty years. It has not been sufficiently realized that a true psychoanalytic understanding of resistance analysis could only begin with Freud's second theory of anxiety. Freud himself never fully embraced this theory, and clinical contributions since then have varied in their ability to use the techniques inherent in the second theory of anxiety. Recent contributions to the literature have not eliminated the espousal of theories of resistance based on earlier views of anxiety. Reasons cited for this include: the ambiguities in Freud's writing, the direction of the early ego theorists, and proclivities toward deeper interpretations.

[Treatment and socioeconomic consequences of skiing injuries in the County of Vejle during the 1986/1987 season]

In a prospective study conducted in the County of Vejle in the skiing-season 1986/1987, the hospitals were contacted by 129 persons who had skiing-injuries. Forty-one patients were primarily treated abroad and 35 patients were primarily examined or treated in Denmark after their return. Fifty-three patients who were injured in Denmark were primarily examined or treated in the casualty ward. The injuries the most often seen were knee and thumb-injuries. Twenty-three operations were undertaken, 15 on knees, and five on thumbs. A total of 139 bed-days were registered, 114 for injuries abroad and 25 for Danish injuries. Fifty-nine injured persons lost 1,481 days on account of sickness. The yearly nationwide costs for the health services in connection with skiing-injuries are calculated to be 9.2 million kroner (approximately 760,000 pounds). The expenses for loss from production are calculated to be 8.6 million kroner (approximately 716,000 pounds).

Drug abuse in schizophrenia and bipolar disorder

The incidence and type of drug abuse for 50 male schizophrenic patients and 60 male and female bipolar, manic patients were determined. Fifty percent of schizophrenic patients and 25% of bipolar patients abused one or more drugs. Alcohol, cannabis, and cocaine accounted for 82% of the drug abuse.

Antitumor activity in vitro in chronic myelogenous leukaemia revealed after treating peripheral cells with cytosine arabinoside

Cytosine arabinoside (Ara-C) treatment of peripheral blood mononuclear cells from 12/12 chronic-phase chronic myelogenous leukaemia (CML) patients revealed a proliferative response stimulated by their untreated leukaemic cells. Specific recognition of tumour cells by patients' normal lymphocytes was suggested by the finding that cells of siblings genotypically identical for human leukocyte antigen caused no stimulation. Lymphocytes thus stimulated by tumour cells from one of these patients were cloned by limiting dilution and tested for antileukaemic effects in cytotoxicity and proliferation assays. Cytotoxic lines were isolated that killed autologous CML targets but only a limited number of allogeneic fresh leukaemias or cell lines. These results show that anti-leukaemia effectors can be isolated from chronic-phase CML patients and suggest their potential application in adoptive immunotherapy.

Division of human helper T cells into two sets on the basis of the induction of anti-tumor cytotoxicity by phorbol ester and calcium ionophore

Fourteen noncytotoxic human helper T cell clones were examined for autocrine proliferative responses and cytotoxicity to tumor cells after stimulation with 12-O-tetradecanoylphorbol 13-acetate (TPA) and ionomycin (Io). Although all clones responded to alloantigen, they could be divided into two groups based on their proliferative response or lack of it to TPA/Io. Nonresponders could not be converted to responder status by addition of interleukin (IL) 1 or indomethacin to the cultures. Responder status did not correlate with any of the following properties of the clones: originating donor, recognitive specificity, B cell helper activity, proliferative response to IL 2 or 4, lymphokine secretory capacity or density of expression of antigen receptors, CD4 or HLA class II molecules. Responder status did, however, correlate with the ability of TPA/Io to induce major histocompatibility complex-unrestricted cytolytic activity directed towards natural killer-resistant tumor cells. These results divide human helper cells into two types on the basis of induction of anti-tumor cytotoxicity.

Studies on the cosubstrate site of protease solubilized NADPH-cytochrome P450 reductase

Modification of the protease solubilized NADPH-cytochrome P450 reductase (= NADPH-cytochrome c reductase) at the critical SH group in the cosubstrate binding site affects KmNADPH but not V for the cytochrome c reduction. The increase of KmNADPH is dependent on the size and the charge of the substituent introduced. Substitution of the cosubstrate site SH by the CN-, S2O3- and the (N-ethyl) succinimido group effects a 3-, 7- and 23-fold increase of KmNADPH, respectively. The critical SH group in the NADPH binding region can be specifically radiolabeled by N-ethyl (2,3-14C) maleimide after preincubation of the reductase with unlabeled NEM in the presence of 1 mM NADP+. The selective reaction at the essential cysteine in the cosubstrate site is demonstrated by peptide mapping of the thermolytic digest and urea SDS gel electrophoresis of the cyanogen bromide fragments of the reductase. Protease solubilized NADPH-cytochrome P450 reductase is inactivated by reagents directed to histidine, arginine and lysine residues. NADP (H) (1 mM) and 2'-AMP (1 mM) give effective protection only for the reaction of 1,2-cyclohexanedione (12 mM). The functional role of the basic amino acid residues for the cosubstrate binding by the NADPH-cytochrome P450 reductase cannot be established therefore by the modification experiments described. The number of NADPH binding sites in the NADPH-cytochrome P450 reductase is determined to one site/mol reductase by titration of the enzyme with NADP+ monitored by CD-spectroscopy.

Parabolic telescope and spectrometer combination

The properties of a nonfocusing collimating parabolic telescope are studied in detail by a ray-tracing method. The best optical quality with respect to coma and astigmatism is calculated for rays close to the optical axis of the telescope. For rectangular fields of view the borders are not sharp because of the aberration. A combination of a parabolic telescope and an echelle-type spectrometer gives very high spectral resolution. Wadsworth, Ebert-Fastie, and other types of spectrometers are equally well suited to be combined with this telescope. For some cases spot diagrams demonstrate the optical performance. In addition, diffraction by the aperture and its implications are discussed.