Natural killer (NK) cell-mediated cytotoxicity: differential use of TRAIL and Fas ligand by immature and mature primary human NK cells

Mature natural killer (NK) cells use Ca2+-dependent granule exocytosis and release of cytotoxic proteins, Fas ligand (FasL), and membrane-bound or secreted cytokines (tumor necrosis factor [TNF]-alpha) to induce target cell death. Fas belongs to the TNF receptor family of molecules, containing a conserved intracytoplasmic "death domain" that indirectly activates the caspase enzymatic cascade and ultimately apoptotic mechanisms in numerous cell types. Two additional members of this family, DR4 and DR5, transduce apoptotic signals upon binding soluble TNF-related apoptosis-inducing ligand (TRAIL) that, like FasL, belongs to the growing TNF family of molecules. Here, we report that TRAIL produced or expressed by different populations of primary human NK cells is functional, and represents a marker of differentiation or activation of these, and possibly other, cytotoxic leukocytes. During differentiation NK cells, sequentially and differentially, use distinct members of the TNF family or granule exocytosis to mediate target cell death. Phenotypically immature CD161(+)/CD56(-) NK cells mediate TRAIL-dependent but not FasL- or granule release-dependent cytotoxicity, whereas mature CD56(+) NK cells mediate the latter two.     

Incontinence and vesical neck strictures following radical retropubic prostatectomy

OBJECTIVES: To evaluate the incidence and severity of vesical neck strictures and urinary incontinence after radical retropubic prostatectomy (RRP) for prostate cancer. METHODS: Between August 1983 and December 1991, 481 consecutive patients underwent RRP by 1 of 2 senior surgeons. Strictures were treated by passing a urethral sound. Incontinence was measured by asking patients for a daily "pad count" of pads required to control urinary leakage. Results were compared to patient age, tumor volume, number of neurovascular bundles spared, preoperative urinary complaints, and previous transurethral resection of the prostate. RESULTS: Of 456 patients with adequate follow-up to determine stricture formation, 82.5% had no strictures, 6.8% required a single dilation, 3.7% required 2 dilations, 3.1% required 3 dilations, and 3.9% required more than 3 dilations. Risk of stricture formation was unrelated to every variable studied. Of 458 patients with adequate follow-up to determine recovery of continence, 80.1% required no pads, 8.1% required 1 to 2 pads a day, 6.6% required 3 to 5 pads a day, and 5.2% were totally incontinent 1 year or more after surgery. Incontinence was closely associated with postoperative urinary urgency. CONCLUSIONS: Strictures are a common but easily managed complication of RRP for prostate cancer. Despite substantial surgical experience, we report a somewhat higher rate of postoperative incontinence than other recently reported series. Our experience is more closely matched by published surveys of patient-reported complications after RRP.     

Improving vineyard sampling efficiency via dynamic spatially explicit optimisation

Background and Aims: Environmental variables within vineyards are spatially correlated, impacting the economic efficiency of cultural practices and accuracy of viticultural studies that utilise random sampling. This study aimed to test the performance of non‐random sampling protocols that account for known spatial structures (‘spatially explicit protocols’) in reducing sampling requirements versus random sampling. Methods and Results: Canopy microclimate data were collected across multiple sites/seasons/training systems. Autocorrelation was found in all systems, with a periodicity generally corresponding to vine spacing. Three spatially explicit sampling models were developed to optimise the balance between minimum sample sizes and maximum fit to a known probability density function. A globally optimised explicit sampling (GOES) model, which performed multivariate optimisation to determine best‐case sampling locations for measuring fruit exposure, reduced fruit cluster sample size requirements versus random sampling by up to 60%. Two stratified sampling protocols were derived from GOES solutions. Spatially weighted template sampling (STS) reduced sampling requirements up to 24% when based on probabilistic panel weighting (PW), and up to 21% when preferentially selecting specific locations within canopy architecture (AW). Conclusions: GOES, PW STS and AW STS each reduced required sample size versus random sampling. Comparative analyses suggested that optimal sampling strategies should simultaneously account for spatial variability at multiple scales. Significance of the Study: This study demonstrates that dynamically optimised sampling can decrease sample sizes required by researchers and/or wineries.     

On the influence of porosity on the portevin-le chatelier effect in sintered iron

Sintered irons of four different porosities were strained in tension at temperatures between 295 (room temperature) and 873 K. Serrated stress-strain curves and high work hardening in the temperature range from 333 to 693 K, for all porosities, were characteristic of dynamic strain aging. The activation energy for the onset of serration was ±0.82 eV and was independent of porosity. On the contrary, the parameter β from the relation for dislocation density increased with increasing porosity.     

Brief note: Differences in intracellular localization of corn stunt spiroplasmas in magnesium treated maize.

Maize plants infected with Spiroplasma kunkelii show symptoms similar to that of plants in a magnesium-deficient soil, and it has been shown that the spiroplasma alters the plants’ magnesium absorption. In the current study we compared changes associated to either spiroplasma infection, two soil magnesium levels and their combinations. Plant symptoms were recorded and correlated with transmission electron microscopy observations. Plants grown on a high magnesium treatment showed no macroscopical alterations nor organelle ultrastructural alterations, while plants on a low magnesium treatment showed macroscopical vein yellowing and, ultrastructurally, they had most chloroplasts and mitochondrial membranes altered. Infected plants on a low magnesium treatment had an ageing aspect, ultrastructurally showed chloroplasts and mitochondrial alterations similar to those non-infected and grown on a low magnesium treatment, and spiroplasma cells were found in phloem cells, but outside their cytoplasm. Infected plants on a high magnesium treatment showed similar symptoms and ultrastructural alterations as either non-infected plants on the low magnesium treatment or in infected plants on the low magnesium treatment, but differ from them in that the spiroplasma cells were located inside the cytoplasm. Results suggest that magnesium is involved in the plant-pathogen interaction.     

Genetic analysis of tissue interactions required for otic placode induction in the zebrafish

Development of the vertebrate inner ear begins during gastrulation with induction of the otic placode. Several embryonic tissues, including cephalic mesendoderm, notochord, and hindbrain, have been implicated as potential sources of otic-inducing signals. However, the relative contributions of these tissues have not been determined, nor have any genes affecting placode induction been identified. To address these issues, we analyzed otic placode induction in zebrafish mutants that are deficient in prospective otic-inducing tissues. Otic development was monitored by examining mutant embryos for morphological changes and, in some cases, by visualizing expression patterns of dlx-3 or pax-2.1 in preotic cells several hours before otic placode formation. In cyclops (cyc-) mutants, which develop with a partial deficiency of prechordal mesendoderm, otic induction is delayed by up to 1 h. In one-eyed pinhead (oep-) mutants, which are more completely deficient in prechordal mesendoderm, otic induction is delayed by 1.5 h, and morphology of the otic vesicles is abnormal. Expression of marker genes in other regions of the neural plate is normal, suggesting that ablation of prechordal mesendoderm selectively inhibits otic induction. In contrast, the timing and morphology of otic development is not affected by mutations in no tail (ntl) or floating head (flh), which prevent notochord differentiation. Similarly, a mutation in valentino (val), which blocks early differentiation of rhombomeres 5 and 6 in the hindbrain, does not delay otic induction, although subsequent patterning of the otic vesicle is impaired. To test whether inductive signals from one tissue can compensate for loss of another, we generated double or triple mutants with various combinations of the above mutations. In none of the multiple mutants do the flh or val mutations exacerbate delays in placode induction, although val does contribute additively to defects in subsequent patterning of the otic vesicle. In contrast, mutants homozygous for both oep and ntl, which interact synergistically to disrupt differentiation of cephalic and axial mesendoderm, show a delay in otic development of about 3 h. These data suggest that cephalic mesendoderm, including prechordal mesendoderm and anterior paraxial mesendoderm, provides the first otic-inducing signals during gastrulation, whereas chordamesoderm plays no discernible role in this process. Because val- mutants are deficient for only a portion of the hindbrain, we cannot rule out a role for that tissue in otic placode induction. However, if the hindbrain does provide otic-inducing signals, they apparently differ quantitatively or qualitatively from the signals required for vesicle patterning, as val disrupts only the latter.     

Reduced quality of life in survivors of acute respiratory distress syndrome compared with critically ill control patients

CONTEXT: Health-related quality of life (HRQL) is reduced in patients who survive acute respiratory distress (ARDS), but whether this decline in HRQL is caused by ARDS or other aspects of the patient's illness or injury is unknown. OBJECTIVE: To determine if there are differences in the HRQL of ARDS survivors and comparably ill or injured controls without ARDS. DESIGN: Prospective, matched, parallel cohort study. SETTING: A 411-bed municipal medical and regional level I trauma center. PATIENTS: Seventy-three pairs of ARDS survivors and severity-matched controls with the clinical risk factors for ARDS of sepsis and trauma admitted between January 1, 1994, and July 30, 1996. MAIN OUTCOME MEASURES: The HRQL of ARDS survivors and controls, assessed by generic and pulmonary disease-specific HRQL instruments (Medical Outcomes Study 36-Item Short Form Health Survey, Standard Form [SF-36] and St George's Respiratory Questionnaire [SGRQ], respectively). RESULTS: Clinically meaningful and statistically significant reductions in HRQL scores of ARDS survivors (n = 73) were seen in 7 of 8 SF-36 domains and 3 of 3 SGRQ domains compared with matched controls (P<.001 for all reductions). The largest decrements in the HRQL were seen in physical function and pulmonary symptoms and limitations. Analysis of trauma-matched pairs (n = 46) revealed significant reductions in 7 of 8 SF-36 domains (P< or =.02) and 3 of 3 SGRQ domains (P< or =.003). Analysis of sepsis-matched pairs (n = 27) revealed significant reductions in 6 of 8 SF-36 domains (P< or =.05) and 3 of 3 SGRQ domains (P< or =.002). CONCLUSIONS: Survivors of ARDS have a clinically significant reduction in HRQL that appears to be caused exclusively by ARDS and its sequelae. Reductions were primarily noted in physical functioning and pulmonary disease-specific domains.     

Rapid resetting of the mammalian circadian clock

The suprachiasmatic nuclei (SCN) contain the principal circadian clock governing overt daily rhythms of physiology and behavior. The endogenous circadian cycle is entrained to the light/dark via direct glutamatergic retinal afferents to the SCN. To understand the molecular basis of entrainment, it is first necessary to define how rapidly the clock is reset by a light pulse. We used a two-pulse paradigm, in combination with cellular and behavioral analyses of SCN function, to explore the speed of resetting of the circadian oscillator in Syrian hamster and mouse. Analysis of c-fos induction and cAMP response element-binding protein phosphorylation in the retinorecipient SCN demonstrated that the SCN are able to resolve and respond to light pulses presented 1 or 2 hr apart. Analysis of the phase shifts of the circadian wheel-running activity rhythm of hamsters presented with single or double pulses demonstrated that resetting of the oscillator occurred within 2 hr. This was the case for both delaying and advancing phase shifts. Examination of delaying shifts in the mouse showed resetting within 2 hr and in addition showed that resetting is not completed within 1 hr of a light pulse. These results establish the temporal window within which to define the primary molecular mechanisms of circadian resetting in the mammal.