Orientation selection in photosynthetic PS I multilayers: structural investigation of the charge separated state P(700)(+z.rad;)A(1)(-z.rad;) by high-field/high-frequency time-resolved EPR at 3.4 T/95 GHz.

The radical-pair state of the primary electron donor and the secondary electron acceptor (P(700)(+z.rad;)A(1)(-z.rad;)) of the photosynthetic reaction center (RC) photosystem I (PS I) of Synechocystis PCC 6803 was studied by time-resolved electron paramagnetic resonance (TREPR) at high field/high frequency (3.4 T/95 GHz) using orientation selection in multilayers. The goal of the present article is to work out the basis for future studies, in which the improved resolution of such multilayers may be used to detect mutation-induced structural changes of PS I in membrane preparations. This approach is particularly interesting for systems that cannot be prepared as single crystals. However, in order to use such multilayers for structural investigations of protein complexes, it is necessary to know their orientation distribution. PS I was chosen as a test example because the wild type was recently crystallized and its X-ray structure determined to 2.5 A resolution [Nature 411 (2001) 909]. On the basis of our experimental results we determined the orientation distribution. Furthermore, a simulation model for the general case in which the orientation distribution is not axially symmetric about the C(2) symmetry axis of the RC is developed and discussed. Spectra simulations show that changes in the TREPR spectra of PS I are much more significant for these oriented multilayers than for disordered samples. In this way the use of oriented multilayers, in conjunction with multifrequency TREPR measurements on oriented as well as on disordered samples, is a promising approach for studies of structural changes of PS I systems that are induced by point mutations.

Fourier-transform EPR at high-field/high-frequency (3.4 T/95 GHz) using broadband stochastic microwave excitation.

Stochastic excitation with a full-width-half-maximum bandwidth of 250 MHz was used to perform Fourier-transform (FT) high-field/high-frequency electron paramagnetic resonance (EPR) at 3.4T/95 GHz (W-band). Thereby, the required microwave peak power is reduced by a factor of tau(p)/T1 as compared to equivalent pulsed FT EPR in which the spin system with spin-lattice relaxation time T1 is excited by a single microwave pulse of length tau(p). Stochastic EPR is particularly interesting under high-field/high-frequency conditions, because the limited output power of mm microwave sources, amplifiers, and mixers makes pulse FT EPR in that frequency domain impossible, at least for the near future. On the other hand, FT spectroscopy offers several advantages compared to field-swept magnetic resonance methods, as is demonstrated by its success in NMR and X-band EPR. In this paper we describe a novel stochastic W-band microwave bridge including a bimodal induction mode transmission resonator that serves for decoupling the microwave excitation and signal detection. We report first EPR measurements and discuss experimental difficulties as well as achieved sensitivity. Moreover, we discuss future improvements and the possibility for an application of stochastic W-band FT EPR to transient signals such as those of photoexcited radical pairs in photosynthetic reaction centers.

Long-term ciclosporine A treatment in adults with minimal change nephrotic syndrome or focal segmental glomerulosclerosis.

To evaluate the efficacy and safety of long-term ciclosporine A (CSA) treatment in idiopathic nephrotic syndrome, we prospectively followed immunosuppressive therapy in 22 nephrotic adults for a median of 32 months (range 7-91 months) and obtained repeat renal biopsies. CSA induced complete remission in 60.0% and 14.3% of patients with minimal change nephrotic syndrome (MCNS) (n = 7), respectively. In addition, partial remissions were achieved in 20.0% of patients with MCNS and in 42.9% of patients with FSGS. Resolution of proteinuria was strictly CSA-dependent and no sustained remission occurred following withdrawal, thereby requiring long-term treatment in 18 patients. In 10 patients CSA was administered for more than 43 months. During maintenance therapy the antiproteinuric effect of CSA was preserved and renal function as well as blood pressure remained stable in patients with MCNS, whereas renal function deteriorated in two patients with FSGS due to progression of the underlying renal disease. Renal biopsies revealed slight signs of CSA toxicity in four patients. However, in no case loss of renal function was attributable to these lesions. In conclusion, the present data suggest that long-term maintenance treatment of MCNS with CSA is efficacious and safe at least for a period of up to 43 months. In contrast, CSA has some effect on proteinuria in FSGS, but the results are less favorable.

Serial kidney biopsies in patients with nephrotic syndrome treated with cyclosporin.

A total of 21 patients with severe steroid-resistant or steroid-dependent nephrotic syndrome have been treated with cyclosporin (CsA) over a period of 6 to 71 months. A permanent treatment was started in patients with complete [c] (proteinuria less than 0.3 g/day) or partial [p] (0.3 to less than 3.0 g/day) remission. In four cases proteinuria was markedly reduced but still greater than 3 g/day. Informed consent was obtained and all patients agreed to further control biopsies. Out of 14 patients treated for longer than 6 months, a fall in creatinine clearance was seen in three cases, including two patients with focal sclerosis who required dialysis treatment. Control biopsies were performed once in 11 and twice in seven patients. In two cases definite CsA-related damage was diagnosed after 1 and 24 months of treatment. Possible CsA-induced damage could not be excluded in three additional cases. In all other biopsies no CsA-related alterations could be demonstrated up to 47 months of treatment. The mean values of the creatinine clearance showed no deterioration. The drop off in a few cases has been related to the basic disease.

Research program development in a tertiary care setting.

The Committee on Clinical Nursing Research was established in April 1979 at the Hospital of the University of Pennsylvania, Philadelphia, not only to encourage clinical nursing research for the provision of optimal care and the development and evaluation of nursing practice, but also to monitor consumer safety vis-à-vis the research effort. The development of the committee and relevant issues are discussed.

A simple method for orthotopic liver transplantation in the rat. Cuff technique for three vascular anastomoses.

A simple method for orthotopic liver transplantation in the rat is described in detail. A cuff technique was applied to all anastomoses of the supra- and infrahepatic venae cavae and the portal vein. It simplified and shortened the implantation of the graft as well as eliminating the need for microvascular suture technique. In the last series of 20 transplants, the survival rate was 85% after 1 week and 55% after 2 months with normal hepatocellular function.

[Deuterium oxide (D2O)--a protective factor for cellular stabilization in hypothermic preservation of the liver? (author's transl)]. / Schweres Waser (D2O)--ein Schutzfakor zur Zellstabilisierung bei der hypothermen Konservierung der Leber?

Rat livers were preserved by ischemic hypothermic storage in extra- or intracellular type solutions for 24 h. A substitution of 85% of the tissue water by deuterium oxide (D2O) resulted in increased glycolytic energy production, better maintenance of the energy potential of the cells but a higher AMP loss, and a reduction of edema formation. Preservation using "retrograde oxygen persufflation" (ROP) resulted in optimal maintenance of the metabolic state which could be further influenced positively by D2O in the total nucleotide content.

Smoking and the heart patient.

It has been shown that inhaled smoke and its toxic constituents, specifically nicotine and carbon monoxide, are positively correlated with an increase in the incidence, progression, and lethal consequences of coronary heart disease. Smoking is a complex habit made up of both pharmacologic and psychosociologic determinants. Unlearning the habit may take time. The nurse is an ideal person to counsel the hospitalized smoker, since she is close to the patient and is seen by the patient as a credible health worker. Once the smoker has begun his relearning process the biggest problem will be staying off cigarettes in the months and years that follow. Family members should be included in the counseling process as they will be needed for support and encouragement. Follow-up is necessary either on a one-to-one basis or in a smoking clinic. In addition to counseling, the nurse has a responsibility to speak our publicly to maintain optimum smoking health standards.