Cleavage of automodified poly(ADP-ribose) polymerase during apoptosis. Evidence for involvement of caspase-7

The abundant nuclear enzyme poly(ADP-ribose) polymerase (PARP) synthesizes poly(ADP-ribose) in response to DNA strand breaks. During almost all forms of apoptosis, PARP is cleaved by caspases, suggesting the crucial role of its inactivation. A few studies have also reported a stimulation of PARP during apoptosis. However, the role of PARP stimulation and cleavage during this cell death process remains poorly understood. Here, we measured the stimulation of endogenous poly(ADP-ribose) synthesis during VP-16-induced apoptosis in HL60 cells and found that PARP was cleaved by caspases at the time of its poly(ADP-ribosyl)ation. In vitro experiments showed that PARP cleavage by caspase-7, but not by caspase-3, was stimulated by its automodification by long and branched poly(ADP-ribose). Consistently, caspase-7 exhibited an affinity for poly(ADP-ribose), whereas caspase-3 did not. In addition, caspase-7 was activated and accumulated in the nucleus of HL60 cells in response to the VP-16 treatment. Furthermore, caspase-7 activation was concommitant with PARP cleavage in the caspase-3-deficient cell line MCF-7 in response to staurosporine treatment. These results strongly suggest that, in vivo, it is caspase-7 that is responsible for PARP cleavage and that poly(ADP-ribosyl)ation of PARP accelerates its proteolysis. Cleavage of the active form of caspase substrates could be a general feature of the apoptotic process, ensuring the rapid inactivation of stress signaling proteins.

Vegetative response during imagined movement is proportional to mental effort

Measurement of cardiac and respiratory activity during mental simulation of locomotion at increasing speed revealed a covariation of heart rate and pulmonary ventilation with the degree of imagined effort. The degree of vegetative activation of a subject mentally running at 12 km/h was comparable to that of a subject actually walking at 5 km/h. This effect cannot be explained by an increase in peripheral (e.g. muscular) metabolic demands. Indeed, oxygen uptake decreased during motor imagery. This finding is suggestive of a commonality of neural structures responsible for mental imagery of movement and those responsible for programming actual movement. In addition, it provides an quantifiable way of testing mental imagery in relation to movement by using easily accessible biological markers.

Factors explaining the intention to give blood among the general population

BACKGROUND AND OBJECTIVES

The aim of this study was to identify factors explaining the intention to donate blood.

MATERIALS AND METHODS

A random sample of 4000 respondents drawn from the general population received a questionnaire by mail. This questionnaire assessed variables as defined by the most prominent social cognitive theories.

RESULTS

Overall, the respondents expressed a neutral mean level of intention to give blood in the next 6 months (2.84 on a five-point scale); 56.2% had never given blood in the past. The variables explaining 74% of the variance of intention were: perceived behavioural control (beta = 0.39; P < 0.001); factors facilitating taking action (beta = 0.25; P < 0.001); anticipated regret (beta = 0.16; P < 0.001); moral norm (beta = 0.11; P < 0.001); attitude (beta = 0.08; P < 0.01); level of education (beta = -0.03; P < 0.05); and past experience in giving blood (beta = 0.09; P < 0.001). Nonetheless, the predictive power of perceived behavioural control and moral norm was higher among the ever donors (both at P < 0.01) compared to the never donors, whereas the reverse was observed for attitude (P < 0.05).

CONCLUSIONS

People's intentions are mainly determined by perceived barriers and obstacles regarding blood donations. This suggests that promotional strategies should focus on the elimination of barriers to action as well as the development of a higher perception of control. Also, messages should be adapted to the targeted population, based on their previous blood donation behaviour (i.e. never donors vs. ever donors).

Dialysis discontinuation and palliative care

Little attention has been accorded to the terminal course and end-of-life care of patients after dialysis discontinuation. This prospective cohort observational study involves six dialysis clinics in the United States and two clinics in Canada. Data were collected on 131 patients who were undergoing maintenance dialysis and died after treatment discontinuation. Seventy-nine of the patients (60%) were prospectively studied until their deaths. Caregivers and families provided information about the symptoms and treatment provided in the final 24 hours of life, and structured interviews were conducted at the time of stopping dialysis with patients and families. The patient population was primarily white (73%), elderly (70 +/- 1.2 years), and diabetic (46%). Three quarters of the subjects had between three and seven comorbid conditions. Pain and agitation were the most common symptoms during the last day of life. Terminal treatment was generally considered to be satisfactory, and most people had good deaths. Although dialysis prolongs life, the integration of palliative medicine into dialysis programs offers opportunities to improve the quality of end-of-life care, especially for those patients who elect to stop treatment. Recommendations include making advance care planning an expectation at all clinics and using quality-of-dying measures to establish benchmarks for the provision of terminal care.

Caspase-3-mediated processing of poly(ADP-ribose) glycohydrolase during apoptosis

Poly(ADP-ribose) glycohydrolase (PARG) is responsible for the catabolism of poly(ADP-ribose) synthesized by poly(ADP-ribose) polymerase (PARP-1) and other PARP-1-like enzymes. In this work, we report that PARG is cleaved during etoposide-, staurosporine-, and Fas-induced apoptosis in human cells. This cleavage is concomitant with PARP-1 processing and generates two C-terminal fragments of 85 and 74 kDa. In vitro cleavage assays using apoptotic cell extracts showed that a protease of the caspase family is responsible for PARG processing. A complete inhibition of this cleavage was achieved at nanomolar concentrations of the caspase inhibitor acetyl-Asp-Glu-Val-Asp-aldehyde, suggesting the involvement of caspase-3-like proteases. Consistently, recombinant caspase-3 efficiently cleaved PARG in vitro, suggesting the involvement of this protease in PARG processing in vivo. Furthermore, caspase-3-deficient MCF-7 cells did not show any PARG cleavage in response to staurosporine treatment. The cleavage sites identified by site-directed mutagenesis are DEID(256) downward arrow V and the unconventional site MDVD(307) downward arrow N. Kinetic studies have shown similar maximal velocity (V(max)) and affinity (K(m)) for both full-length PARG and its apoptotic fragments, suggesting that caspase-3 may affect PARG function without altering its enzymatic activity. The early cleavage of both PARP-1 and PARG by caspases during apoptosis suggests an important function for poly(ADP-ribose) metabolism regulation during this cell death process.

Elliptic flow of charged particles in Pb-Pb collisions at sqrt[S(NN)] = 2.76 TeV

We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at sqrt[S(NN)] =2.76 TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region (|η|<0.8) and transverse momentum range 0.2<p t<5.0 GeV/c. The elliptic flow signal v₂, measured using the 4-particle correlation method, averaged over transverse momentum and pseudorapidity is 0.087 ± 0.002(stat) ± 0.003(syst) in the 40%-50% centrality class. The differential elliptic flow v₂ p t reaches a maximum of 0.2 near p t =3 GeV/c. Compared to RHIC Au-Au collisions at sqrt[S(NN)] 200 GeV, the elliptic flow increases by about 30%. Some hydrodynamic model predictions which include viscous corrections are in agreement with the observed increase.

Transverse-momentum and collision-energy dependence of high-pT hadron suppression in Au+Au collisions at ultrarelativistic energies

We report high statistics measurements of inclusive charged hadron production in Au+Au and p+p collisions at sqrt[s(NN)]=200 GeV. A large, approximately constant hadron suppression is observed in central Au+Au collisions for 5<p(T)<12 GeV/c. The collision energy dependence of the yields and the centrality and p(T) dependence of the suppression provide stringent constraints on theoretical models of suppression. Models incorporating initial-state gluon saturation or partonic energy loss in dense matter are largely consistent with observations. We observe no evidence of p(T)-dependent suppression, which may be expected from models incorporating jet attenuation in cold nuclear matter or scattering of fragmentation hadrons.

Agonistic and antagonistic properties of the bradykinin B2 receptor antagonist, Hoe 140, in isolated blood vessels from different species

1. Hoe 140, a recently described bradykinin B2 antagonist, and NPC 567 from an earlier generation of bradykinin B2 antagonists, were tested in rabbit and sheep isolated blood vessels. 2. In rabbit jugular vein, a bradykinin B2 preparation, NPC 567 was an antagonist (apparent pA2: 8.67 +/- 0.16) with marked residual agonistic activity (log[EC50]: -7.29 +/- 0.13). Hoe 140 was a potent non-competitive antagonist devoid of agonistic properties (slope of the Schild plot: 2.02; estimated pA2: 9.04). 3. In rabbit aorta, a bradykinin B1 preparation, NPC 567 was a competitive antagonist (pA2: 6.32 +/- 0.13) but Hoe 140 was ineffective. The two antagonists did not show any agonistic properties in this tissue. 4. In sheep femoral artery without endothelium, bradykinin and Hoe 140 induced contractions with identical efficacy and similar potency (log[EC50]: -8.05 +/- 0.12, -7.73 +/- 0.10; maximal contraction in % of KCl [60 mM]: 59.5 +/- 15.1, 62.0 +/- 13.1; for bradykinin and Hoe 140, respectively). In contrast NPC 567 was an extremely weak agonist. The contractile responses to bradykinin and Hoe 140 were inhibited by NPC 567 (apparent pKB: 6.89 +/- 0.22 and 6.58 +/- 0.08 versus bradykinin and Hoe 140, respectively) but not by a B1 bradykinin antagonist, suggesting that the receptor involved was a bradykinin B2 receptor. 5. In sheep femoral artery with endothelium, bradykinin induced a biphasic response: an endothelium-dependent relaxation and a contraction which were both inhibited by NPC 567 (apparent pKB: 7.10 +/- 0.15) and Hoe 140 (pA2: 8.38 +/- 0.12). As bradykinin B2 receptor antagonists, Hoe 140 and NPC 567 were less potent in the sheep femoral artery than in the rabbit jugular vein. Neither Hoe 140 nor NPC 567 were agonists for the endothelial receptor.6. This study demonstrates that Hoe 140, a new bradykinin B2 receptor antagonist, is more selective and more potent than NPC 567; however, it may possess, depending on the tissue studied, marked residual agonistic properties. Furthermore, bradykinin B2 receptors are subject to important species specificity. Finally, two different bradykinin B2 receptor subtypes may coexist in the sheep femoral artery with endothelium.

Water balance during and after marathon running

To describe the time course of plasma volume alterations and the changes in the plasma concentrations of hormones regulating water balance in relation to a marathon race, six experienced marathon runners (five men, one women) aged 28 (SD 6) years were studied during and for the 3 days following a treadmill marathon run at 68 (SD 5) percent of maximal oxygen consumption. Haematocrit, haemoglobin, plasma protein (Prot) and electrolyte (Na+, K+) concentration, osmolality (osm), plasma concentrations of renin (Ren), aldosterone (Ald) and atrial natriuretic peptide (ANP) were determined at rest in a sitting position (T(-30)), and then after 30 min in an upright posture (R(0)), while running a marathon at 10 km (R(10)), 30 km (R(30)) and 42.2 km (R end), and after the marathon at 30 min (T(30)), 60 min (T(60)), 120 min (T(120)) and 24 h (TD(+1)), 48 h (TD(+2)) and 72 h (TD(+3)). The changes in plasma volume (PV), Prot, osm and Na+ observed during the race were nonsignificant. Significant increases in plasma concentration of K+ [4.8 (SD 0.6) vs 5.5 (SD 0.6) mmol*1(-1); P <0.01], Ren [38(SD 57) vs 197 (SD 145) pmol*1(-1); P <0.02] and Ald [175 (SD 142) vs 1632 (SD 490) pmol*1(-1); P <0.01] were observed at R(end). A significant increase of ANP (P <0.05) was only found after R(10). Body mass significantly decreased by 2.0 kg (P <0.01) during the race in spite of the ingestion of 1.46 (SD 0.34)1 of a 5 percent glucose solution. Urinary volume and Na+ excretion dropped significantly after the completion of the marathon in comparison with the day before [2600 vs 1452 ml*day(-1)(P <0.02) and 161.3 vs 97.1 mmol*1(-1) (P <0.05)]. At TD(+1) and TD(+2) a significant increase in PV was noted, compared to T(-30). The lack of a decrease in PV during the marathon may have been due to the production of 402 g of metabolic water and by the release of 1280 g of water stored in glycogen complexes in muscle and liver. Thus, the hormone response during the marathon may have been due to the effects of the exercise itself and not to the effects of dehydration. The postmarathon PV expansion may be explained by a protein shift to the intravascular space and by renal sodium retention.

Centrality dependence of high-p(T) hadron suppression in Au+Au collisions at sqrt[s(NN)]=130 GeV

Inclusive transverse momentum distributions of charged hadrons within 0.2<p(T)<6.0 GeV/c have been measured over a broad range of centrality for Au+Au collisions at sqrt[s(NN)]=130 GeV. Hadron yields are suppressed at high p(T) in central collisions relative to peripheral collisions and to a nucleon-nucleon reference scaled for collision geometry. Peripheral collisions are not suppressed relative to the nucleon-nucleon reference. The suppression varies continuously at intermediate centralities. The results indicate significant nuclear medium effects on high-p(T) hadron production in heavy-ion collisions at high energy.

Yellow fever in the Gambia, 1978--1979: epidemiologic aspects with observations on the occurrence of orungo virus infections

An epidemic of yellow fever (YF) occurred in the Gambia between May 1978 and January 1979. Retrospective case-finding methods and active surveillance led to the identification of 271 clinically suspected cases. A confirmatory or presumptive laboratory diagnosis was established in 94 cases. The earliest serologically documented case occurred in June 1978, at the extreme east of the Gambia. Small numbers of cases occurred in August and September. The epidemic peaked in October, and cases continued to occur at a diminishing rate through January, when a mass vaccination campaign was completed. The outbreak was largely confined to the eastern half of the country (MacCarthy Island and Upper River Divisions). In nine survey villages in this area (total population 1,531) the attack rate was 2.6--4.4%, with a mortality rate of 0.8%, and a case fatality rate of 19.4%. If these villages are representative of the total affected region, there may have been as many as 8,400 cases and 1,600 deaths during the outbreak. The disease incidence was highest in the 0- to 9-year age group (6.7%) and decreased with advancing age to 1.7% in persons over 40 years. Overall, 32.6% of survey village inhabitants had YF complement-fixing (CF) antibodies. The prevalence of antibody patterns indicating primary YF infection decreased with age, in concert with disease incidence. The overall inapparent:apparent infection ratio was 12:1. In persons with serological responses indicating flaviviral superinfection, the inapparent:apparent infection ratio was 10 times higher than in persons with primary YF infection. Sylvatic vectors of YF virus, principally Aedes furcifer-taylori and Ae. luteocephalus are believed to have been responsible for transmission, at least at the beginning of the outbreak. Eighty-four percent of wild monkeys shot in January 1979 had YF neutralizing antibodies, and 32% had CF antibodies. Domestic Aedes aegypti were absent or present at very low indices in many severely affected villages (see companion paper). In January, however, aegypti-borne YF 2.5 months into the dry season was documented by isolation of YF virus from a sick man and from this vector species in the absence of sylvatic vectors. Thus, in villages where the classical urban vector was abundant, interhuman transmission by Ae. aegypti occurred and continued into the dry season. A mass vaccination campaign, begun in December, was completed on 25 January, with over 95% coverage of the Gambian population. A seroconversion rate of 93% was determined in a group of vaccinees. This outbreak emphasizes the continuing public health importance of YF in West Africa and points out the need for inclusion of 17D YF vaccination in future programs of multiple immunication.

Squamous cell carcinoma in situ (Bowen's disease) in renal transplant patients treated with 5% imiquimod and 5% 5-fluorouracil therapy

BACKGROUND

Depending upon the patient's age at transplant, skin type, sun exposure, and the need for immunosuppressive therapy to prevent rejection, there is escalation in the development of cutaneous malignancies in organ transplant patients a number of years after transplantation. Thus, with the expansion in these procedures over the past decades, and the ever-lengthening survival of these patients, we are seeing an increase in cutaneous malignancies in this patient population.

OBJECTIVE

To determine if combined therapy with 5% 5-fluorouracil and 5% imiquimod may be useful in the treatment of squamous cell carcinoma in situ.

METHODS

We present five renal transplant patients, all more than 10 years posttransplantation, three with insulin-dependent diabetes, who developed multiple areas of squamous cell carcinoma (SCC) in situ. All these patients were on chronic immunosuppressive chemotherapy to prevent rejection, but were otherwise doing well. All the patients had biopsy-proven SCC in situ on their lower extremities that even in normal patients may be a challenge to treat.

RESULTS

We treated these five patients with a combination of a local immune therapy, imiquimod cream, and a topical chemotherapeutic agent, 5% 5-fluorouracil (5-FU), with clearing of the areas of SCC in situ.

CONCLUSION

Although immunotherapy must be used with caution in organ transplant patients to avoid graft rejection, topical imiquimod is a local immune modulator that potentiates local innate and possible adaptive immunity without measurable effects on systemic immunity. In addition, there is evidence that cytokines induced by imiquimod may improve the therapeutic efficacy of topical 5% 5-FU in the treatment of SCC in situ.

Genital flora in pregnancy and its association with intrauterine growth retardation

A study of risk factors for intrauterine growth retardation (IUGR) was conducted among a cohort of 13,914 pregnant women enrolled in the multicenter Vaginal Infections and Prematurity Study. From 23 through 26 weeks of gestational age, cultures of specimens from the vagina and cervix were done for group B streptococci, Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis, Candida albicans, Gardnerella vaginalis, Mycoplasma hominis, Ureaplasma urealyticum, and anaerobic gram-negative rods belonging to the genera Bacteroides, Porphyromonas, and Prevotella. Newborns who were small for their gestational age were delivered by 1,251 women, and infants of the appropriate weight for their gestational age were delivered by 10,332 women. When controlling for ethnicity and smoking and excluding women treated with antibiotics, the Mantel-Haenszel adjusted relative risk of IUGR was 1.16 for Bacteroides, Prevotella, and Porphyromonas spp. (95% confidence interval [95% CI], 1.01 to 1.33), 1.16 for M. hominis (95% CI, 1.04 to 1.29), 1.20 for U. urealyticum (95% CI, 1.05 to 1.38), and 1.22 for T. vaginalis (95% CI, 1.05 to 1.42). There was also a strong and significant trend for an increasing risk of IUGR with the number of these four microbes recovered. Among women colonized with all four isolates, the adjusted odds ratio of IUGR was 1.79 (95% CI, 1.27 to 2.52) in comparison with women not colonized with any of these microorganisms. Group B streptococci, N. gonorrhoeae, C. trachomatis, and C. albicans were not significantly associated with IUGR. These results suggest that infection is associated with some cases of IUGR and that specific microorganisms, alone or in combination, are involved. Since genital isolates are highly correlated with each other, the relative contribution of each microbe is difficult to determine.

Centrality dependence of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at sqrt[s(NN)] = 2.76 TeV

The centrality dependence of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at sqrt[s_{NN}]=2.76  TeV is presented. The charged-particle density normalized per participating nucleon pair increases by about a factor of 2 from peripheral (70%-80%) to central (0%-5%) collisions. The centrality dependence is found to be similar to that observed at lower collision energies. The data are compared with models based on different mechanisms for particle production in nuclear collisions.

Management of intermittent ovarian torsion by laparoscopic oophoropexy

BACKGROUND

Ovarian torsion is a serious gynecologic condition that often results in adnexal removal. If recurrent, this can result in castration of young patients. Torsion in the pediatric population is rare, but it presents more management challenges for gynecologists. There are few reports of prophylactic oophoropexy in patients with intermittent torsion.

CASE

A patient with a history of left adnexal torsion was treated with salpingo-oophorectomy at age 10. She subsequently presented at age 12 with right lower quadrant pain, and was found to have a 7 x 6 cm right adnexal mass on ultrasound examination. She was diagnosed with ovarian edema secondary to intermittent torsion. At laparoscopy, she was found to have a 3-cm utero-ovarian ligament. She was treated with laparoscopic shortening of the utero-ovarian ligament, and has remained symptom-free for 1 year.

CONCLUSION

We believe that this is the first reported case of laparoscopic triplication of the utero-ovarian ligament to prevent recurrent torsion. In young patients, this treatment may be a reasonable alternative to oophoropexy as prophylaxis for ovarian torsion.

Immunological determination and size characterization of poly(ADP-ribose) synthesized in vitro and in vivo

Poly(ADP-ribose) polymerase is a DNA break detecting enzyme playing a role in the surveillance of genome integrity. Poly(ADP-ribose) is synthesized rapidly and transiently from beta-NAD in response to DNA damaging agents. In order to study the physiological significance of poly(ADP-ribose) metabolism, we have developed immunological methods which enable us to study endogenous poly(ADP-ribose) without interfering with cell metabolism and integrity. For this purpose, we produced a highly specific polyclonal anti-poly(ADP-ribose) antibody which immunoreacts with polymers and oligomers. In addition to the immunodot blot method recently described by us (Affar et al., Anal. Biochem. 259 (1998) 280-283), other applications were investigated in cells: (i) detection of poly(ADP-ribose) by ELISA; (ii) characterization of poly(ADP-ribose) size using high resolution gel electrophoresis of polymers, followed by its transfer onto a positively charged membrane and detection with anti-poly(ADP-ribose) antibody; (iii) immunocytochemistry and flow cytometry analyses allowing poly(ADP-ribose) study at the level of individual cells.

Higher harmonic anisotropic flow measurements of charged particles in Pb-Pb collisions at sqrt(s(NN)) = 2.76 TeV

We report on the first measurement of the triangular v3, quadrangular v4, and pentagonal v5 charged particle flow in Pb-Pb collisions at sqrt(s(NN)) = 2.76  TeV measured with the ALICE detector at the CERN Large Hadron Collider. We show that the triangular flow can be described in terms of the initial spatial anisotropy and its fluctuations, which provides strong constraints on its origin. In the most central events, where the elliptic flow v2 and v3 have similar magnitude, a double peaked structure in the two-particle azimuthal correlations is observed, which is often interpreted as a Mach cone response to fast partons. We show that this structure can be naturally explained from the measured anisotropic flow Fourier coefficients.

Reduced food intake in response to CGP 71683A may be due to mechanisms other than NPY Y5 receptor blockade

INTRODUCTION

The purpose of this study was to test the continuing validity of the hypothesis that neuropeptide Y (NPY) produced in the brain controls food intake through an interaction with the NPY Y(5) receptor subtype.

METHODS

The hypothesis was tested using CGP 71683A a potent and highly selective non-peptide antagonist of the NPY Y(5) receptor which was administered into the right lateral ventricle of obese Zucker fa/fa rats.

RESULTS

Intraventricular injection of 3.4 nmol/kg NPY increased food intake during a 2 h test period. Doses of CGP 71683A in excess of 15 nmol/kg (i.cv.) resulted in blockade of the increase in food intake produced by NPY. Repeated daily injection of CGP 71683A (30--300 nmol/kg, i.cv.) immediately before the dark phase produced a dose-dependent and slowly developing decrease in food intake. CGP 71683A has a low affinity for NPY Y(1), Y(2) and Y(4) receptors but a very high affinity for the NPY Y(5) receptor (Ki, 1.4 nM). Surprisingly, CGP 71683A had similarly high affinity for muscarinic receptors (Ki, 2.7 nM) and for the serotonin uptake recognition site (Ki, 6.2 nM) in rat brain. Anatomic analysis of the brain after treatment with CGP 71683A demonstrated an inflammatory response associated with the fall in food intake.

CONCLUSIONS

While the fall in food intake in response to CGP 71683A may have a Y(5) component, interactions with other receptors or inflammatory mediators may also play a role. It is concluded that CGP 71683A is an imprecise tool for investigating the role of the NPY Y(5) receptor in the control of physiological processes including food intake. International Journal of Obesity (2001) 25, 84-94

Disappearance of back-to-back high-pT hadron correlations in central Au+Au collisions at sqrt[s NN ] =200 GeV

Azimuthal correlations for large transverse momentum charged hadrons have been measured over a wide pseudorapidity range and full azimuth in Au+Au and p+p collisions at sqrt[s(NN)]=200 GeV. The small-angle correlations observed in p+p collisions and at all centralities of Au+Au collisions are characteristic of hard-scattering processes previously observed in high-energy collisions. A strong back-to-back correlation exists for p+p and peripheral Au+Au. In contrast, the back-to-back correlations are reduced considerably in the most central Au+Au collisions, indicating substantial interaction as the hard-scattered partons or their fragmentation products traverse the medium.

Denying the dying. Advance directives and dialysis discontinuation

A structured interview was administered to a sample of patients on maintenance dialysis and their attending physicians to obtain information on the documentation of their end-of-life treatment preferences. The majority of the patients reported never having considered stopping dialysis, or having discussed with their nephrologist or family the circumstances in which treatment should be discontinued. Only 7 patients (6%) had completed an advance directive; these patients were all men (P = 0.01) and tended to be better educated (P = 0.02). Only one of the nine physicians had completed an advance directive. In most cases, the dialysis patients and their treatment team staff were preoccupied with the struggles of daily life and had avoided or denied considerations of terminal illness and death. The literature on denial, medical illness, and dying is also reviewed as it relates to dialysis patients, end-of-life treatment, and terminal care.

The risks and benefits of accepting men who have had sex with men as blood donors

BACKGROUND

It has been suggested that men who have had sex with men (MSM) should become eligible to donate blood if they recently abstained from male-to-male sex.

STUDY DESIGN AND METHODS

The impact of a 12-month deferral policy for MSM on the risk of introducing contaminated units in the blood supply and the benefit of obtaining additional donations were estimated. Considered were the prevalence of HIV among MSM, the window period of infection, the rate of laboratory testing errors, and the occurrence of other system failures. This was compared with the risk and benefit that currently results from accepting female donors who have had sex with MSM.

RESULTS

The revised policy for MSM would potentially result in one HIV-contaminated unit for every 136,000 additional donations (95% CI, 1 in 69,000 to 1 in 268,000), for an overall increase in HIV risk estimated at 8 percent. The number of donations would increase by 1.3 percent (95% CI, 0.9%-1.7%). The risk-benefit ratio of currently accepting female partners of MSM is approximately five times lower.

CONCLUSION

The risk increment of accepting 12-month abstinent MSM would be very small but not zero. From a risk-benefit perspective, the current deferral policy for MSM is more efficient compared to an analogous hypothetical criterion for female partners of MSM.

Tympanic temperatures during hemiface cooling

In adult men the left half of the head was covered with thick heat insulation, and the right hemiface was cooled by spraying a mist of water, and vigorous fanning. The subjects were immersed up to the waist in warm water (42 degrees) to achieve hyperthermia. In control sessions the subjects were rendered slightly hypothermic by preliminary exposure to cold. Under the hypothermic condition during right skin cooling, the right Tty remained low as compared with oesophageal temperature, while the left Tty was raised. Under the hyperthermic condition right hemiface cooling maintained not only the right Tty lower than oesophageal but also, to a lesser extent the left Tty, while the skin on the left side was close to core temperature. This latter result cannot be explained by conductive cooling from the skin to the tympanic membrane and implies a vascular cooling of the left Tty originating from the other side of the head. It is concluded that selective cooling of the brain takes place during hyperthermia. The main mechanism is forced vascular convection, but conductive cooling also occurs.

Cross sections and transverse single-spin asymmetries in forward neutral-pion production from proton collisions at sqrt[s]=200 GeV

Measurements of the production of forward high-energy pi(0) mesons from transversely polarized proton collisions at sqrt[s]=200 GeV are reported. The cross section is generally consistent with next-to-leading order perturbative QCD calculations. The analyzing power is small at x(F) below about 0.3, and becomes positive and large at higher x(F), similar to the trend in data at sqrt[s]< or =20 GeV. The analyzing power is in qualitative agreement with perturbative QCD model expectations. This is the first significant spin result seen for particles produced with p(T)>1 GeV/c at a polarized proton collider.