Protein assembly and heat stability in developing thylakoid membranes during greening

The development of the thylakoid membrane was studied during illumination of dark-grown barley seedlings by using biochemical methods, and Fourier transform infrared and spin label electron paramagnetic resonance spectroscopic techniques. Correlated, gross changes in the secondary structure of membrane proteins, conformation, composition, and dynamics of lipid acyl chains, SDS/PAGE pattern, and thermally induced structural alterations show that greening is accompanied with the reorganization of membrane protein assemblies and the protein-lipid interface. Changes in overall membrane fluidity and noncovalent protein-lipid interactions are not monotonic, despite the monotonic accumulation of chlorophyll, LHCII [light-harvesting chlorophyll a/b-binding (polypeptides) associated with photosystem II] apoproteins, and 18:3 fatty acids that follow a similar time course with highest rates between 12-24 h of greening. The 18:3 fatty acid content increases 2.8-fold during greening. This appears to both compensate for lipid immobilization by membrane proteins and facilitate packing of larger protein assemblies. The increase in the amount of protein-solvating immobile lipids, which reaches a maximum at 12 h, is caused by 40% decrease in the membranous mean diameter of protein assemblies at constant protein/lipid mass ratio. Alterations in the SDS/PAGE pattern are most significant between 6-24 h. The size of membrane protein assemblies increases approximately 4.5-fold over the 12-48-h period, likely caused by the 2-fold gain in LHCII apoproteins. The thermal stability of thylakoid membrane proteins increases monotonically, as detected by an increasing temperature of partial protein unfolding during greening. Our data suggest that a structural coupling between major protein and lipid components develops during greening. This protein-lipid interaction is required for the development and protection of thylakoid membrane protein assemblies.     

Low-cost, small-animal shelf for simultaneously assessing several small animals with a whole-body PET scanner

OBJECTIVE: The purpose of this work was to establish a low-cost device for simple positioning of several small animals within a whole-body PET scanner. METHODS: The device was designed as a stackable shelf for 3 x 3 animals, similar to a stackable shelf for wine bottles. It was constructed from ordinary PVC drain pipe and acrylic panes. RESULTS: The shelf simplified accurate and reproducible positioning of the animals and, therefore, supported automatic data processing. Deterioration of image quality by attenuation of photons within the shelf itself was rather small. CONCLUSION: The small-animal shelf is a useful, low-cost device for simultaneously assessing up to 9 small animals with a whole-body PET scanner.     

Training and overtraining markers in selected sport events

PURPOSE: Varieties of symptoms are supposed to detect overtraining (OT). Besides the problems of diagnosis and analysis in elite athletes, a daily monitoring of training status takes place with measurement of the parameters serum urea (SU) and serum creatine kinase (CK); therefore, their meaningfulness will be examined, with special respect inter- and intra-individually. METHODS: Data were obtained from determinations during training from athletes in rowing and athletes of international level. RESULTS: For 6981 SU determinations (male, N = 717; female, N = 285), a slightly asymmetric normal distribution was found (male, 80%, 5-7 mmol x L(-1); female, 75%, 4-6 mmol x L(-1)). Values for women were approximately 1.5 mmol x L(-1) lower. Individual variability was enormous; there seems little point in setting fixed value as 8.3 mmol x L(-1) for men and 7.0 mmol x L(-1) for women as a critical limit for OT. CK has also been measured and evaluated in sports as an essential parameter for determination of muscular stress. Frequency distributions of CK in 2790 samples (male, N = 497; female, N = 350) presented an asymmetric normal distribution with distinct trend toward higher values being evident for the range between 100 and 250 U x L(-1). Conspicuously elevated values occurred in the ranges 250-350 U x L(-1) and 1000-2000 U x L(-1). Men's maximal values were 3000 U x L(-1) and 1150 U x L(-1) for women. Individual variability was enormous. Athletes with chronically low CK exhibited mainly low variability; those with chronically higher values exhibited considerable variability. CONCLUSIONS: Establishment of both parameters should be useful to determine individual baselines from a large number of samples. Determinations should be made at least every 3 d in standardized conditions. If a large increase is observed in combination with reduced exercise tolerance after a phase of exertion (2-4 d), then the possibility of a catabolic/metabolic activity or insufficient exercise tolerance becomes much more likely.     

The fitness of the mental patient to be a witness

The determination of whether a patient has criminal responsibility or is able to stand trial is routine psychiatric work. Cases in which we- psychiatrists- are asked to express our opinion on whether a patient can testify, however, are quite rare. We shall attempt to clarify some of the issues relating to the testimony of mentally ill patients through a case presentation. In this case, the Court agreed to consider our patient's testimony, only after receiving our expert opinion. We find that the Court's reversal of its original decision and its willingness to consider the testimony of a mental patient in the same trial in which he was initially found unable to stand trial, marks an important precedent. The question of the credibility of the mental patient as a witness has significance beyond this case concerning mental patients' rights in regard to the judicial system. We believe there is a need for further discussion between psychiatrists andjurists regarding the fitness of the mental patient to testify as a witness.     

Has Israel and the Russian Federation legislation a full set of laws securing the protection of mental patients relative to United Nations' proposals and do they require modification?

This paper compares sections of laws dealing with the care and protection of mental patients in Israel and in the Russian Federation and matches them with the 24 recommendations on the subject proposed by the United Nations (UN) in 1988. Particular attention is given to issues related to forensic and ethical subjects. The UN proposals constitute a most laudable reform-inducing guideline for global mental health care systems, especially because of their emphasis on the preservation of mental patients' basic human rights. The proposals' strength springs from their influence regarding the prevention of misuse of psychiatry with focus on the care of inpatients and control over executive agencies. The detailed analysis of the similarities between the Israeli and Russian legislative approach reveals some badly matched organizational structure of many articles in comparison with the UN mandate. Forensic and ethical concepts present in the UN 1988 proposals are well addressed in both the Israeli and Russian mental health legislation. We conclude that the 1991 UN recommendations would demand further modification of the national standards.     

Complications of endoscopic sinus surgery: Analysis of 2108 patients—incidence and prevention

The incidence of complications of endoscopic sinus surgery (ESS) in a combined experience with 2108 total patients is compared to complications in 11 other series of patients (2583 total) who underwent ESS and 6 series of patients (2110 total) who underwent traditional endonasal sinus surgery. The incidence of major perioperative complications was 0.85%, with cerebrospinal fluid (CSF) leak being the most common. The most common minor complications of ESS were those related to orbital penetration and middle turbinate adhesions; minor complications occurred in 6.9% of the 2108 patients. There were no statistically significant differences in the overall incidences of major complications between this series and the other two groups. Recommendations are made for the prevention of complications during ESS.     

Influence of body tilt within the sagittal plane on odor identification performance

Odor identification performance, nasal airflow resistance, blood pressure, and heart rate were assessed in 8 men and 8 women in the following body tilt positions within the sagittal plane: 0 degree (upright), 90 degrees (supine), 135 degrees, and 180 degrees (upside down). The order of testing across the tilt conditions was systematically counterbalanced using a Latin square procedure. Average odor identification performance decreased monotonically as a function of increased body tilt. Significant decreases in heart rate and blood pressure were observed as the body was tilted from the upright condition, although blood pressure was equivalent in the upright and upside down conditions. Nasal resistance was highly variable and was not systematically altered as a function of body tilt. These data support the hypothesis that olfactory function, like visual, auditory, and vestibular function, is significantly influenced by body position within a gravitational field.     

Hyperkalaemia: a complication of warm heart surgery

A case is presented of hyperkalaemia (13.6 mEq · L^?1) occurring during cardiopulmonary bypass using warm blood cardioplegia (K⁺ 40–60 mEq · L^?1). Treatment with epinephrine, calcium chloride, sodium bicarbonate, and furosemide reduced K⁺ to 6.5 mEq · L^?1 within 30 min and myocardial performance was enhanced with amrinone and cardiac rhythm was controlled with A-V segmental pacing. It is believed that the hyperkalaemia resulted from a combination of the surgical procedure (mitral valve replacement) and the use of warm cardioplegia. The purpose of this report is to increase the awareness of the possibility of hyperkalaemia with warm cardioplegia and to describe a successful therapeutic regimen.     

Acetylcholine releasing effect of laser irradiation on Auerbach's plexus in guinea-pig ileum

Summary An increased acetylcholine release could be produced by ruby laser from the Auerbach plexus of the guinea-pig ileum.