Sailfish generate foraging opportunities for seabirds in multi-species predator aggregations.

While various marine predators form associations, the most commonly studied are those between subsurface predators and seabirds, with gulls, shearwaters or terns frequently co-occurring with dolphins, billfish or tuna. However, the mechanisms underlying these associations remain poorly understood. Three hypotheses have been proposed to explain the prevalence of these associations: (1) subsurface predators herd prey to the surface and make prey accessible to birds, (2) subsurface predators damage prey close to the surface and thereby provide food scraps to birds, and (3) attacks of underwater predators lower the cohesion of prey groups and thereby their collective defences making the prey easier to be captured by birds. Using drone footage, we investigated the interaction between Indo-Pacific sailfish (Istiophorus platypterus) and terns (Onychoprion sp.) preying on schooling fish off the eastern coast of the Malaysian peninsula. Through spatio-temporal analysis of the hunting behaviour of the two predatory species and direct measures of prey cohesion we showed that terns attacked when school cohesion was low, and that this decrease in cohesion was frequently caused by sailfish attacks. Therefore, we propose that sailfish created a by-product benefit for the bird species, lending support to the hypothesis that lowering cohesion can facilitate associations between subsurface predators and seabirds.

California sea lions interfere with striped marlin hunting behaviour in multi-species predator aggregations.

The open ocean offers a suite of ecological conditions promoting the occurrence of multi-species predator aggregations. These mixed predator aggregations typically hunt large groups of relatively small and highly cohesive prey. However, the mechanisms and functions of these mixed predator aggregations are largely unknown. Even basic knowledge of whether the predator species' interactions are mutualistic, commensal or parasitic is typically missing. Moreover, recordings of attack and capture rates of marine multi-species predator aggregations, which are critical in understanding how and why these interactions have evolved, are almost completely non-existent owing to logistical challenges. Using underwater video, we quantified the attack and capture rates of two high-trophic level marine predators, California sea lions (Zalophus californianus) and striped marlin (Kajikia audax) attacking schools of fishes in the Southern California Current System, offshore the Baja California Peninsula. Recording over 5000 individual attacks across 13 fish schools, which varied in species, size and predator composition, we found that sea lions kleptoparasitized striped marlin hunts and reduced the frequency of marlin attacks and captures via interference competition. We discuss our results in the context of the phenotypic differences between the predator species and implications for a better understanding of multi-species predator aggregations. This article is part of the theme issue 'Mixed-species groups and aggregations: shaping ecological and behavioural patterns and processes'.

[Extra-articular manifestations of rheumatoid arthritis]. / Extraartikuläre Manifestationen der rheumatoiden Arthritis.

Rheumatoid arthritis (RA) represents an autoimmune disease affecting mostly joints, in particular small finger and toe joints. In addition RA can show extra-articular manifestations in many organs. Information on the frequency of extra-articular manifestations (EAMs) in RA varies greatly in different publications from 17.8% to 40.9% and EAMs tend to become higher with increasing duration and severity of the disease. The exact etiology and pathogenesis are still unclear but vasculitic alterations together with deposition of immune complexes can often be found histopathologically in affected organs. It must also be taken into consideration that EAMs can also be a result of the pharmaceutical therapy. The organ findings can vary greatly which is also reflected in the multitude of clinical symptoms. Possible target organs are the blood vessels, kidneys, central nervous system, cardiovascular system, the lungs, eyes, skin, nails as well as blood and the hemopoetic system. The prognosis for RA becomes progressively worse in the presence of EAMs. Regular and continuous control investigations are necessary in order to be able to diagnose EAMs early and to begin therapy. Therapy includes the administration of non-steroidal anti-inflammatory drugs (NSAIDs) and disease-modifying antirheumatic drugs (DMARDs) and especially in advanced stages cyclophosphamide or biologicals. Therapy is still very empirical due to the lack of appropriate studies.

[Therapy refractory polyarthritis and fever]. / Therapierefraktäre Polyarthritis und Fieber.

Primary manifestation of an autoinflammatory systemic disease was found in a 15-year-old patient, which initially ran a fulminant course. The course was first controlled by therapy with steroids and cyclosporin A. In the course of the disease, the patient developed a therapy refractory polyarthritis, which failed to respond to a combination of disease-modifying antirheumatic drugs (DMARDs) and tumor necrosis factor (TNF) inhibitors. A good disease control could only be achieved with an interleukin 6 (IL-6) blockade and DMARDs.

Communication between receptors for different ligands on a single cell: ligation of fibronectin receptors induces a reversible alteration in the function of complement receptors on cultured human monocytes.

Receptors for the third component of complement (C3) on cultured human monocytes (MO) bind ligand-coated particles but do not initiate phagocytosis. The function of these receptors, however, is altered dramatically after MO attach to surfaces coated with fibronectin (FN) or after MO are exposed to phorbol esters. FN and phorbol esters "activate" C3 receptors such that they promote vigorous phagocytosis. Here we show that activation of C3 receptors requires the continuous presence of FN or phorbol esters and is rapidly reversible when these stimuli are removed. Activation does not change the number or distribution of C3 receptors on the surface of MO. We conclude that the function of C3 receptors is regulated by reversible reactions that are initiated by ligation of a different class of receptors on the surface of the same cell.

Macrophages are required for influenza virus infection of human lymphocytes.

Monocyte and lymphocyte surface-expressed viral antigens have been demonstrated after exposure of unseparated human mononuclear leukocytes to influenza virus in vitro. The current studies, using [35S]methionine pulse-labeled purified preparations of virus-exposed macrophages, depleted of lymphocytes, demonstrate that the presence of these viral proteins does represent new synthesis. However, purified lymphocytes, depleted of monocytes-macrophages and exposed to influenza virus, showed no detectable viral protein synthesis. In further experiments, unseparated mononuclear leukocytes were exposed to virus and subsequently separated by countercurrent centrifugal elutriation. Both macrophages and lymphocytes were then shown to synthesize influenza proteins. Cell-free control or influenza virus-infected macrophage-derived supernatant fluids did not facilitate influenza virus infection of the lymphocytes. The data suggest that macrophages are required for influenza virus infection of human lymphocytes, and raise the possibility that macrophage facilitation of an abortive infection of lymphocytes plays a role in the generation of effective immunity to viral antigens.

Chronic effects of direct vasodilation (pinacidil), alpha-adrenergic blockade (prazosin) and angiotensin-converting enzyme inhibition (captopril) in systemic hypertension.

Chronic responses of systemic hemodynamics and blood pressure counterregulatory ("pseudo-tolerance") mechanisms were investigated in matched groups of patients with essential hypertension after 1 month of vasodilator therapy with pinacidil (a direct arterial dilator), prazosin (an alpha 1-adrenergic blocking drug) or captopril (an angiotensin-converting enzyme inhibitor). For equivalent decreases in mean arterial pressure compared with placebo baseline (approximately 8 mm Hg supine and 12 mm Hg upright), prazosin and captopril did not increase cardiac index or heart rate. In contrast, marked decreases in systemic vascular resistance with pinacidil (approximately 25%, p less than 0.05) were accompanied by reflex increases in cardiac index (approximately 20%, p less than 0.05). Activity of the sympathetic nervous system, measured by supine and upright plasma norepinephrine (NE), increased approximately 50% with pinacidil and prazosin (p less than 0.001 each), whereas captopril decreased supine plasma NE by 12% (p less than 0.05) and did not change upright plasma NE. All 3 drugs caused an expansion of height-adjusted blood volume (approximately 14%). Pinacidil and prazosin caused reversible weight gains of 0.9 and 0.7 kg, respectively, whereas captopril reversibly decreased body weight by 0.8 kg (p less than 0.05), suggesting differential effects of the 3 drugs on interstitial fluid volume. During chronic therapy, all 3 drugs may require concomitant diuretic therapy, whereas concomitant sympatholytic therapy may be required with the potent vasodilator pinacidil. Captopril may be associated with the lowest cardiac risk because of its lack of stimulatory effects on the sympathetic nervous system and cardiac index.

Humoral effect of norepinephrine on renin release in humans.

We compared the effects of infused norepinephrine (NE) to another alpha-adrenergic agonist, phenylephrine, in order to understand better the influence of circulating NE on plasma renin activity (PRA) in man. In matched groups of normotensive men, NE (80 ng/min/kg) or phenylephrine (800 ng/min/kg) raised blood pressure by 15 to 20 mm Hg and caused reflex decreases in heart rate of 8 to 10 beats per minute. Infused phenylephrine suppressed PRA by about 15%, whereas NE increased PRA by about 40% (P less than .02). This differential effect of alpha-agonists on PRA defines an important humoral effect of NE, which should be considered to be a "cardiovascular hormone."

Early hospital discharge after radical retropubic prostatectomy: impact on cost and complication rate.

OBJECTIVES: To assess the impact of shortened hospital stay after radical retropubic prostatectomy for localized prostate cancer on complication rates and hospital costs. METHODS: A comparison of results between 171 consecutive patients undergoing radical retropubic prostatectomy between July 1989 and January 1993 (group 1) and 101 consecutive patients operated on since February 1993 (group 2) during a prospective effort to reduce hospital length of stay by home-based preoperative bowel preparation, direct admission to the operating room on the day of surgery, earlier and more extensive postoperative ambulation, earlier initiation of postoperative oral intake, earlier use of oral analgesics, and routine pelvic drain removal at 72 to 96 hours after surgery independent of volume of drainage. RESULTS: Median length of stay was reduced from 8 to 5 days (p < 0.0001, group 1 versus group 2), with 10% of patients in group 2 having hospital stays of 4 days or less. The overall nature and rate of complications (13.5% versus 11.9%, p = NS) were similar in both groups. Reduced length of stay was associated with a 32% decrease in hospital-associated cost per case in group 2 versus group 1 for patients in diagnosis-related group (DRG) 334 (radical prostatectomy with comorbidity) and a 26% decrease for DRG 335 (radical prostatectomy without comorbidity). CONCLUSIONS: Reduced hospital length of stay after radical retropubic prostatectomy results in significant cost savings without increasing morbidity.

Immediate impotence after penetrating perineal trauma: restoration of erections with penile artery revascularization, corpus cavernosum aneurysm repair, and deep penile venous ligation.

Erectile dysfunction can result from blunt or penetrating pelvic or perineal trauma. Rupture of the corpora cavernosa leading to loss of the veno-occlusive mechanism and penile artery occlusion have been found in these patients. We present a case of immediate loss of erectile function after penetrating perineal trauma resulting in corpus cavernosum rupture and traumatic occlusion of multiple arteries in the hypogastric-cavernous bed. Conservative management of the corpus injury resulted in post-traumatic aneurysmal dilation at the site of injury with venous leakage from aberrant veins. Penile arterial revascularization and aneurysm repair with deep penile venous ligation resulted in near-complete return of normal erectile function.

Impact of bladder neck preservation during radical prostatectomy on continence and cancer control.

OBJECTIVES: To assess the effect of preservation of the bladder neck and other factors on the rate of postoperative urinary continence and cancer control after radical prostatectomy. METHODS: Prospective analysis of clinical and pathologic findings in 206 consecutive patients undergoing radical prostatectomy with a surgical technique that emphasizes preservation of periurethral supporting tissue, urethral length, incorporation of the posterior periurethral fascia into the vesicourethral anastomosis, and preservation of the bladder neck. RESULTS: Uni- and multivariate statistical analysis demonstrated that patient age (p = 0.033) and vesical neck contracture (p = 0.047) were predictive of incomplete return of urinary control. Preservation of the vesical neck had no impact on return of continence, but was associated with a trend to a lower incidence of vesical neck contractures. A positive bladder neck margin occurred in 6.8% of surgical specimens and was associated with a higher grade, more advanced local stage, and other positive margins in all cases. The rate of local recurrence or prostate-specific antigen (PSA)-only failure was similarly independent of whether the vesical neck was preserved or resected and reconstructed. CONCLUSIONS: Age greater than 65 and occurrence of a vesical neck contracture are adverse predictors for return of urinary continence after radical prostatectomy. Preservation of the bladder neck does not have an impact on return of urinary control but may be associated with a lower risk of vesical neck contracture. Preservation of the bladder neck does not compromise cancer control as assessed by local or PSA-only failure rates.

Management of small unilateral renal cell carcinomas: radical versus nephron-sparing surgery.

OBJECTIVES: There is controversy concerning the management of small unilateral renal cell carcinomas. The present study was undertaken to evaluate the relative efficacy of radical nephrectomy versus nephron-sparing surgery in such patients. METHODS: Patients with a single, small (less than 4 cm), localized, unilateral, sporadic renal cell carcinoma (RCC) were identified from an institutional registry. From 1975 to 1992, 88 patients fulfilling these criteria were treated with either radical nephrectomy (n = 42) or nephron-sparing surgery (n = 46). The mean postoperative follow-up interval is 48 +/- 29 months. RESULTS: The radical and nephron-sparing surgical groups were well matched for patient age, sex, renal function, diabetes, hypertension, tumor size, tumor location, and tumor stage. All patients in both groups had low pathologic stage RCC. There was no difference between the two groups in terms of the mean hospital stay, the requirement for blood transfusions, or the occurrence of surgical complications. There was no difference in the mean preoperative and postoperative serum creatinine levels for patients in the nephron-sparing surgery group. However, the mean postoperative serum creatinine levels were significantly higher than the mean preoperative levels for patients in the radical nephrectomy group (P < 0.001). A single patient in each group developed recurrent RCC postoperatively. The cancer-specific 5-year survival rate for patients in the radical and nephron-sparing surgical groups is 97% and 100%, respectively. CONCLUSIONS: Radical nephrectomy and nephron-sparing surgery each provide safe and effective curative treatment for patients with a single, small, unilateral localized RCC. The long-term renal functional advantage of nephron-sparing surgery in this setting is not established.

Clinical application of intracytoplasmic sperm injection using in vitro cultured testicular spermatozoa obtained the day before egg retrieval.

OBJECTIVE: To study the effect of in vitro culture on the quality of human testicular sperm and the efficiency of intracytoplasmic sperm injection with in vitro cultured testicular sperm. DESIGN: Clinical study. SETTING: A private IVF center. PATIENT(S): Twenty consecutively seen IVF patients undergoing testicular biopsies for ICSI. INTERVENTION(S): The testicular specimens were cultured in vitro for 24 hours and the isolated spermatozoa were microinjected. MAIN OUTCOME MEASURE(S): Preincubation and postculture sperm motility, and fertilization, implantation, and pregnancy rates after intracytoplasmic sperm injection. RESULT(S): Motility increased from initial nonmotile or twitching sperm to free motile sperm in 18 of 20 cases. The injection of in vitro cultured testicular sperm resulted in a fertilization rate of 58%, an implantation rate of 20%, and a pregnancy rate of 45%. CONCLUSION(S): A testicular biopsy procedure can be performed the day before egg retrieval. Despite the low initial sperm quality, a high percentage of the prepared testicular sperm showed increased motility after 24 hours of culture. The injection of in vitro cultured testicular sperm into matured oocytes resulted in fertilization, implantation, and pregnancy rates comparable to those obtained with ejaculated sperm.

A comparison of objective classroom measures and teacher ratings of Attention Deficit Disorder.

Children identified as Attention Deficit Disorder (ADD) on the basis of teacher ratings using the SNAP Rating Scale were compared to non-ADD children on objective classroom measures including observations of classroom behavior, examination of the organization of children's desks, and scoring of daily academic work. Analyses provided some support for the ability of the objective measures to differentiate between teacher-identified ADD and non-ADD children, though there was considerable overlap on the distributions of most variables between groups. Six measures chosen by a discriminant analysis combined to predict teacher ratings in 83% of the cases. The inclusion of academic, observational, and desk measures in the discriminant function indicates the importance of a multivariate assessment of this construct.

The differential validity of teacher ratings of inattention/overactivity and aggression.

The ability of school-based measures of child behavior to predict differentially the IOWA Conners teacher rating scale Inattention/Overactivity (IO) and Aggression (A) factors was evaluated in a sample of 71 school-aged boys. Multiple measures and multiple methods of assessment were utilized to provide a comprehensive assessment of social and academic behavior. These included direct observations of children in the classroom and on the playground, examination of the organization of children's desks, measures of academic performance, peer nominations of popularity and rejection, and sociometric ratings using the Pupil Evaluation Inventory. Despite moderately high correlations between the teacher rating factors (r = .60), considerable evidence was provided for differential validity on measures of academic performance, peer rating measures, and measures of disruptive or inappropriate classroom and playground behavior. These differences between IO and A factors indicated that the factors were logically independent in important ways, supporting prior work validating separate hyperactivity and aggression dimensions.

Sildenafil (Viagra) for treating male erectile dysfunction.

Sildenafil, the first oral drug for treating male erectile dysfunction, appears effective and well tolerated. However, more time and experience will be needed to establish this drug's true efficacy and safety.

Use of oral sildenafil (Viagra) in the treatment of erectile dysfunction.

Erectile dysfunction is a common problem affecting men. Sildenafil (Viagra) is the first oral medication approved for the treatment of erectile dysfunction. It has proven to be an effective option in the treatment of erectile dysfunction of different etiologies.

Does pre-dialysis care management reap rewards for patients, renal staff, and payers.

This article describes one renal disease management organization's experience in implementing a pre-dialysis care management program to improve outcomes in patients who develop end-stage renal disease (ESRD). Optimal Renal Care, a national renal disease management company, has implemented care management programs for 600+ ESRD patients and 600+ pre-ESRD patients in Oregon (1998) and Hawaii (1999). This article describes our Oregon pre-ESRD program's start-up experience.