Locally rare species influence grassland ecosystem multifunctionality

Species diversity promotes the delivery of multiple ecosystem functions (multifunctionality). However, the relative functional importance of rare and common species in driving the biodiversity-multifunctionality relationship remains unknown. We studied the relationship between the diversity of rare and common species (according to their local abundances and across nine different trophic groups), and multifunctionality indices derived from 14 ecosystem functions on 150 grasslands across a land-use intensity (LUI) gradient. The diversity of above- and below-ground rare species had opposite effects, with rare above-ground species being associated with high levels of multifunctionality, probably because their effects on different functions did not trade off against each other. Conversely, common species were only related to average, not high, levels of multifunctionality, and their functional effects declined with LUI. Apart from the community-level effects of diversity, we found significant positive associations between the abundance of individual species and multifunctionality in 6% of the species tested. Species-specific functional effects were best predicted by their response to LUI: species that declined in abundance with land use intensification were those associated with higher levels of multifunctionality. Our results highlight the importance of rare species for ecosystem multifunctionality and help guiding future conservation priorities.

Landscape simplification filters species traits and drives biotic homogenization

Biodiversity loss can affect the viability of ecosystems by decreasing the ability of communities to respond to environmental change and disturbances. Agricultural intensification is a major driver of biodiversity loss and has multiple components operating at different spatial scales: from in-field management intensity to landscape-scale simplification. Here we show that landscape-level effects dominate functional community composition and can even buffer the effects of in-field management intensification on functional homogenization, and that animal communities in real-world managed landscapes show a unified response (across orders and guilds) to both landscape-scale simplification and in-field intensification. Adults and larvae with specialized feeding habits, species with shorter activity periods and relatively small body sizes are selected against in simplified landscapes with intense in-field management. Our results demonstrate that the diversity of land cover types at the landscape scale is critical for maintaining communities, which are functionally diverse, even in landscapes where in-field management intensity is high.

Land use intensification alters ecosystem multifunctionality via loss of biodiversity and changes to functional composition

Global change, especially land‐use intensification, affects human well‐being by impacting the delivery of multiple ecosystem services (multifunctionality). However, whether biodiversity loss is a major component of global change effects on multifunctionality in real‐world ecosystems, as in experimental ones, remains unclear. Therefore, we assessed biodiversity, functional composition and 14 ecosystem services on 150 agricultural grasslands differing in land‐use intensity. We also introduce five multifunctionality measures in which ecosystem services were weighted according to realistic land‐use objectives. We found that indirect land‐use effects, i.e. those mediated by biodiversity loss and by changes to functional composition, were as strong as direct effects on average. Their strength varied with land‐use objectives and regional context. Biodiversity loss explained indirect effects in a region of intermediate productivity and was most damaging when land‐use objectives favoured supporting and cultural services. In contrast, functional composition shifts, towards fast‐growing plant species, strongly increased provisioning services in more inherently unproductive grasslands.

Preperitoneal prosthetic mesh hernioplasty during radical retropubic prostatectomy

PURPOSE

The number of radical retropubic prostatectomies performed in the United States has increased during the last decade. There are 5 to 10% of candidates for radical retropubic prostatectomy who have a detectable inguinal hernia on physical examination. Furthermore, recent data suggest that there is an increased incidence of inguinal hernia after radical retropubic prostatectomy. We evaluated the role of simultaneous inguinal hernioplasty during radical prostatectomy.

MATERIALS AND METHODS

During 575 radical prostatectomy procedures from June 1991 to June 1997, 70 hernioplasties were performed in 48 patients. Retrospective chart review was performed for all men who underwent simultaneous hernia repair. Mean patient age was 60.9 years (range 43 to 73). Polypropylene or polyester fiber prostheses were used for mesh hernioplasty. All repairs were performed using a preperitoneal approach during radical retropubic prostatectomy.

RESULTS

There were 35 hernioplasties performed without and 35 with mesh. Mean postoperative followup was 24 months (range 6 to 66). Of the hernias 71% were indirect and 29% were direct. No recurrence was detected after mesh hernioplasty, whereas 5 hernias (14%) recurred in the nonmesh group. In this group 2 men (4%) also had de novo hernias on the contralateral side during followup. All recurrent hernias were diagnosed within 1 year of the initial operation. No patient had wound infection, persistent neuralgia or ischemic orchitis.

CONCLUSIONS

Simultaneous repair of inguinal hernias during radical retropubic prostatectomy is effective and technically feasible. There is convenient access to the preperitoneal space during radical retropubic prostatectomy and hernia repair adds only 5 to 10 minutes of operative time. Mesh repair appears to offer optimized results compared to the nonmesh technique. Despite the use of prosthetic material, no complications were attributable to its application during these genitourinary procedures.

A directly spliced exon 10-containing CD44 variant promotes the metastasis and homotypic aggregation of aggressive non-Hodgkin's lymphoma

Variants of the CD44 cell-surface adhesion molecule include additional sequences encoded by combinations of exons from the membrane proximal domain (exons 6-14). Preliminary studies suggest that these additional variable membrane proximal sequences may alter the ligand specificity, glycosylation, and biologic function of CD44. In earlier studies, we found that primary extranodal and widely disseminated aggressive non-Hodgkin's lymphomas (NHLs) and normal activated B cells expressed a directly spliced exon 10-containing variant (CD44ex10), whereas normal resting B cells expressed larger exon 10-containing variants (CD44ex10-14 and CD44ex7-14). To obtain additional information regarding the function of exon 10-containing CD44 variants in aggressive NHL, we generated aggressive NHL transfectants that expressed CD44ex10, CD44ex10-14, CD44ex7-14, the standard CD44 isoform (CD44H), or vector alone, and evaluated the local tumorogenicity, aggregation, and metastatic potential of these transfectants. CD44ex10 aggressive NHL transfectants were more likely to cause local tumor formation in nude mice than transfectants expressing the larger exon 10-containing variants, CD44H, or vector alone. In addition, cell suspensions derived from CD44ex10 local tumors exhibited far greater homotypic aggregation than those obtained from other CD44 or vector-only local tumors. In nude mice that received CD44ex10 transfectants, distant metastases were also significantly more likely to develop than in animals that were given either the CD44ex10-14, CD44ex7-14, CD44H, or vector-only transfectants. These data provide the first evidence that the directly spliced exon 10-containing CD44 variant (CD44ex10) has a unique biologic function in aggressive NHL.

Microfocal prostate cancer: biopsy cancer volume does not predict actual tumour volume

OBJECTIVE

To determine whether microfocal prostate cancer on needle biopsy predicts clinically insignificant disease in men undergoing radical prostatectomy.

PATIENTS AND METHODS

The records of 726 men who underwent radical prostatectomy between January 1990 and September 1995 were reviewed; 83 men had pre-operative prostatic needle biopsies which revealed microfocal prostate cancer. In these men, tumour volume (length) in the biopsy was compared to the percentage of tumour in the total prostatectomy specimen, and the pathological stage and clinical outcome reviewed.

RESULTS

Of the 83 men with microfocal prostate cancer on biopsy 75 (90%) had clinically significant disease. Pre-operative variables were of no use in identifying patients with clinically insignificant tumour volumes. When comparing those with microfocal tumour and those without at one institution, 69% had organ-confined (pT2) disease and 31% had capsular penetration (pT3), compared with 61% and 39%, respectively (P < 0.05). Additionally, the positive surgical margin rate for those with microfocal tumour was only 6%, compared with 26% for those without microfocal disease (P < 0.05). Biochemical failures during the median follow-up period of 24 months occurred in 6% of the men with microfocal cancer and in 15% of those undergoing total prostatectomy (P < 0.05).

CONCLUSIONS

Microfocal prostate cancer determined from the needle biopsy does not predict clinically insignificant disease.

Histological and bacteriological findings in long-term ileocystoplasty and colocystoplasty in the rat

The long-term effects of bladder reconstruction using bowel were studied in rats. Bladder surgery consisted of cystotomy and closure, ileo- or colocystoplasty, or placement of a reverse serosal (Thal) patch of ileum. At least one-third of all groups received prophylactic cefaclor, postoperatively. Monthly urine cultures were obtained, and survivors were sacrificed at 1 year. Antimicrobial therapy markedly reduced the incidence of chronic colonization after cystoplasty. However, the majority of rats in the Thal patch group remained colonized because of acquired vesicoileal fistulae. Vesical stones were often present in this group and were also seen in 6 of 43 (14%) and 3 of 33 (9%) in the ileocystoplasty and colocystoplasty groups, respectively. Transitional cell papillomas and/or hyperplasia was seen at 20 of 42 (48%) uroileal and 20 of 31 (64%) urocolonic anastomoses (p = .15). Hyperplastic lesions could not be correlated with bacteriuria. Focal nonpapillary transitional cell carcinoma was seen once in the colocystoplasty group, and low grade papillary transitional cell tumors were noted once in each of the cystostomy and ileocystoplasty groups and twice in Thal patch rats with ileovesical fistulae. These findings suggest that the rat uroenteric anastomosis is susceptible to proliferative change which is rarely malignant in nature and occurs in the presence or absence of bacteriuria.

The contemporary incidence of lymph node metastases in prostate cancer: implications for laparoscopic lymph node dissection

The incidence of lymphatic metastases in 229 consecutive patients with clinically localized prostatic cancer was assessed. Only 13 patients had nodal metastases, for an incidence of 5.7%. A monoclonal prostatic specific antigen value of more than 40 ng./ml. correlated with a positive predictive value of 53% for nodal metastases. Routine laparoscopic node dissection is unnecessary considering the low incidence of nodal metastases.

Motile sperm in human testis biopsy specimens

We prospectively studied 62 consecutive infertile men who underwent 100 intraoperative wet prep cytological examinations of testis biopsy material obtained simultaneously with permanently fixed specimens. Wet preps were performed by placing a small sample of fresh testicular tissue on a slide, adding a drop of Ringer's lactate, and compressing the specimen under a glass coverslip. Among these 100 wet preps, complete sperm with tails were identified in 62 specimens, of which 44 contained nonmotile sperm and 18 contained motile sperm. Reproductive tract obstruction was documented in 65 testes (65%) on subsequent reconstructive surgery and/or inferred from histological evaluation, including mean mature spermatid counts on the permanent sections fixed in Bouin's solution. Obstruction was absent in the remaining testes (35%). All 18 testes with motile sperm found on wet prep were obstructed. These testes were also found to have complete spermatogenesis, a category selected to include normal spermatogenesis and slight hypospermatogenesis, determined by examination of the permanently fixed sections. The finding of motile vs. nonmotile sperm on a wet prep has positive predictive values of 100% vs. 81% for the presence of reproductive tract obstruction and 94% vs. 86% for complete spermatogenesis, respectively. The presence of motile sperm in human testis biopsy specimens is a novel finding. When any complete sperm with tail is found in a testis biopsy wet prep, obstruction is likely. When motile sperm are present, obstruction is almost certain, and immediate exploration and reconstructive surgery can be justified.(ABSTRACT TRUNCATED AT 250 WORDS)

Uretero-fallopian tube fistula secondary to laparoscopic fulguration of pelvic endometriosis

Ureteral injuries during laparoscopic surgery have been documented. We present a case of the diagnosis and management of a uretero-fallopian tube fistula after laparoscopic laser fulguration of pelvic endometriosis.

Relationship between varicocele size and response to varicocelectomy

We studied the relationship between varicocele size and response to surgery in 86 men with a unilateral left varicocele who reported either infertility (83), pain (1) or pain and testicular atrophy (2). Varicoceles were graded according to size: grade 1--small (22 patients), grade 2--medium (44) and grade 3--large (20). Sperm count, per cent motility, per cent tapered forms and fertility index (sperm count times per cent motility) were measured preoperatively and postoperatively. Preoperatively, men with grade 3 varicocele had lower sperm counts and poorer fertility indexes compared to men with grades 1 and 2 varicocele. Sperm concentration improved significantly in men with grade 2 (33 +/- 5 million per cc preoperatively to 41 +/- 6 million postoperatively, p < 0.04) and grade 3 (18 +/- 5 million preoperatively to 32 +/- 7 million postoperatively) varicocele after microsurgical ligation of the varicocele. Motility improved significantly in men with grade 3 varicocele. Decrease in per cent tapered forms was significant in all groups. A comparison of per cent change in fertility index among the groups revealed that men with grade 3 varicocele improved to a greater degree (128%) than men with grade 1 (27%) or grade 2 (21%) varicocele. Pregnancy rates 2 years postoperatively were 40% for grade 1, 46% for grade 2 and 37% for grade 3 varicocele patients. The difference in pregnancy rates among the groups was not statistically significant. In conclusion, infertile men with a large varicocele have poorer preoperative semen quality but repair of the large varicocele in those men results in greater improvement than repair of a small or medium sized varicocele.

Kinetic properties and inhibition of Acinetobacter glutaminase-asparaginase

Kinetic parameters, substrate specificity and exclusivity of ligands at binding sites of L-glutaminase-L-asparaginase purified from Acinetobacter glutaminasificans were studied in order to gain knowledge about the dual activities of this enzyme and its inhibition by structural analogs. Both L-glutamine and L-asparagine, which showed similar Km (4 approximately 7 X 10(-5) M) and Vmax (molecular activity 1.0 min-1) values, were competitive with each other for the substrate binding site. The products, L-glutamic acid and L-aspartic acid, showed competitive inhibition with respect to either L-glutamine or L-asparagine as substrates. Multiple inhibition of the glutaminase activity by L-glutamic acid and L-aspartic acid indicated that these ligands are mutually exclusive at the product-releasing site. The initial rates of both of the enzyme's activities were competitively inhibited by the following inhibitors (in rates of both of the enzyme's activities were competitively inhibited by the following inhibitors (in decreasing order of activity): 6-diazo-5-oxo-L-norleucine (DON), L-methionine sulfoximine, azaserine, and Acivicin. DON and azaserine inhibited both the asparaginase and glutaminase activities in a time-dependent and irreversible manner. The kinetic data suggest an ordered mechanism with glutamine or asparagine as the first substrate and glutamic acid or aspartic acid, respectively, as the last product. These results also suggest that a single mechanism and a single set of binding sites are responsible for catalyzing both of the enzyme's activities. The data also showed that succinylated enzyme, which has a 10-fold increase of plasma half-life in animals and humans and, thus, has benefit as a cancer chemotherapeutic agent, retained its catalytic activity and maintained Km and Vmax values similar to the native enzyme.