Cellular localization of membrane-type serine protease 1 and identification of protease-activated receptor-2 and single-chain urokinase-type plasminogen activator as substrates

Membrane-type serine protease 1 (MT-SP1) was recently cloned, and we now report its biochemical characterization. MT-SP1 is predicted to be a type II transmembrane protein with an extracellular protease domain. This localization was experimentally verified using immunofluorescent microscopy and a cell-surface biotinylation technique. The substrate specificity of MT-SP1 was determined using a positional scanning-synthetic combinatorial library and substrate phage techniques. The preferred cleavage sequences were found to be (P4-(Arg/Lys)P3-(X)P2-(Ser)P1-(Arg)P1'-(Ala)) and (P4-(X)P3-(Arg/Lys)P2-(Ser)P1(Arg) P1'(Ala)), where X is a non-basic amino acid. Protease-activated receptor 2 (PAR2) and single-chain urokinase-type plasminogen activator are proteins that are localized to the extracellular surface and contain the preferred MT-SP1 cleavage sequence. The ability of MT-SP1 to activate PARs was assessed by exposing PAR-expressing Xenopus oocytes to the soluble MT-SP1 protease domain. The latter triggered calcium signaling in PAR2-expressing oocytes at 10 nm but failed to trigger calcium signaling in oocytes expressing PAR1, PAR3, or PAR4 at 100 nm. Single-chain urokinase-type plasminogen activator was activated using catalytic amounts of MT-SP1 (1 nm), but plasminogen was not cleaved under similar conditions. The membrane localization of MT-SP1 and its affinity for these key extracellular substrates suggests a role of the proteolytic activity in regulatory events.

Rapid and general profiling of protease specificity by using combinatorial fluorogenic substrate libraries

A method is presented for the preparation and use of fluorogenic peptide substrates that allows for the configuration of general substrate libraries to rapidly identify the primary and extended specificity of proteases. The substrates contain the fluorogenic leaving group 7-amino-4-carbamoylmethylcoumarin (ACC). Substrates incorporating the ACC leaving group show kinetic profiles comparable to those with the traditionally used 7-amino-4-methylcoumarin (AMC) leaving group. The bifunctional nature of ACC allows for the efficient production of single substrates and substrate libraries by using 9-fluorenylmethoxycarbonyl (Fmoc)-based solid-phase synthesis techniques. The approximately 3-fold-increased quantum yield of ACC over AMC permits reduction in enzyme and substrate concentrations. As a consequence, a greater number of substrates can be tolerated in a single assay, thus enabling an increase in the diversity space of the library. Soluble positional protease substrate libraries of 137, 180 and 6,859 members, possessing amino acid diversity at the P4-P3-P2-P1 and P4-P3-P2 positions, respectively, were constructed. Employing this screening method, we profiled the substrate specificities of a diverse array of proteases, including the serine proteases thrombin, plasmin, factor Xa, urokinase-type plasminogen activator, tissue plasminogen activator, granzyme B, trypsin, chymotrypsin, human neutrophil elastase, and the cysteine proteases papain and cruzain. The resulting profiles create a pharmacophoric portrayal of the proteases to aid in the design of selective substrates and potent inhibitors.

Synthesis of positional-scanning libraries of fluorogenic peptide substrates to define the extended substrate specificity of plasmin and thrombin

We have developed a strategy for the synthesis of positional-scanning synthetic combinatorial libraries (PS-SCL) that does not depend on the identity of the P1 substituent. To demonstrate the strategy, we synthesized a tetrapeptide positional library in which the P1 amino acid is held constant as a lysine and the P4-P3-P2 positions are positionally randomized. The 6,859 members of the library were synthesized on solid support with an alkane sulfonamide linker, and then displaced from the solid support by condensation with a fluorogenic 7-amino-4-methylcoumarin-derivatized lysine. This library was used to determine the extended substrate specificities of two trypsin-like enzymes, plasmin and thrombin, which are involved in the blood coagulation pathway. The optimal P4 to P2 substrate specificity for plasmin was P4-Lys/Nle (norleucine)/Val/Ile/Phe, P3-Xaa, and P2-Tyr/Phe/Trp. This cleavage sequence has recently been identified in some of plasmin's physiological substrates. The optimal P4 to P2 extended substrate sequence determined for thrombin was P4-Nle/Leu/Ile/Phe/Val, P3-Xaa, and P2-Pro, a sequence found in many of the physiological substrates of thrombin. Single-substrate kinetic analysis of plasmin and thrombin was used to validate the substrate preferences resulting from the PS-SCL. By three-dimensional structural modeling of the substrates into the active sites of plasmin and thrombin, we identified potential determinants of the defined substrate specificity. This method is amenable to the incorporation of diverse substituents at the P1 position for exploring molecular recognition elements in proteolytic enzymes.

Nested cladistic analysis indicates population fragmentation shapes genetic diversity in a freshwater mussel

Recently developed phylogeographic analyses that incorporate genealogical relationships of alleles offer the exciting prospect of disentangling historical from contemporary events. However, the relative advantages and shortfalls of this approach remain to be studied. We compared the nested cladistic method to the more traditional analysis of variance approach in a study of intraspecific genetic variation in the freshwater mussel, Lampsilis hydiana. We surveyed 257 specimens for nucleotide sequence level variation in a fragment of the mitochondrial 16S rRNA gene. When compared side by side, nested cladistic analysis and analysis of molecular variance (AMOVA) identified fragmentation of Arkansas river populations from remaining populations to the southwest. Nested cladistic analysis identified a second, more recent separation of Ouachita and Upper Saline river populations that was not detected by AMOVA. Differences among analytical methods probably arise from treatment of spatial hierarchical information: hierarchical groups emerge via a parsimony criterion in nested cladistic analysis but must be specified a priori in AMOVA. Both methods identified significant genetic structure among localities within hierarchical groups. Results from AMOVA suggested little gene flow among local populations with an island model. However, inferences about process that gave rise to patterns at this level were not possible in nested cladistic analysis, because an ancestral (interior) haplotype was not observed for a key one-step clade in the parsimony network. Our results suggest that, under some circumstances, nested cladistic analysis has lower power than more traditional analysis of variance to infer processes at the local population level.

Physiologic basis of antenatal testing

Hypoxic injury accounts for approximately 20 to 40% of stillbirths in published autopsy series. Antepartum fetal testing modalities can discriminate between the fetus at risk for hypoxic injury and the normally oxygenated fetus. These modalities have resulted in a significant reduction in this category of stillbirths. The physiologic underpinning for the antepartum testing is reviewed with a brief discussion of the two major approaches to testing.

Developing a protocol to prevent and treat pediatric central venous catheter occlusions

Catheter occlusions are a common occurrence in pediatric patients with central venous catheters. These occlusions are attributable to many factors, such as mechanical problems caused by catheter and patient size, clot formation caused by blood product administration and laboratory sampling, drug precipitation, and lipid residues. Because of the significant patient risk and cost involved in replacing occluded central venous catheters, a multidisciplinary team used a quality improvement approach to determine the effectiveness of urokinase in pediatric patients. Data from the project enabled development of a decision tree for urokinase use. Statistics from the pilot test revealed that 85% of the catheter occlusions were related to thrombotic events, and urokinase was effective in all cases. However, 15% of central line occlusions were related to medication precipitates and were not effectively cleared with urokinase. Given the evidence that urokinase is effective only on fibrin-related occlusions, the decision tree was modified to improve success with occlusions caused by medication precipitates.

Urban African American adolescent parents: their perceptions of sex, love, intimacy, pregnancy, and parenting

This study examined the perceptions of twenty-two urban African American adolescent mothers and six adolescent fathers (across seven grade levels and a general education equivalency program) regarding sex, love, intimacy, pregnancy, and parenting. Structured interviews and focus groups were used to gather data. Demographic and personal history information was also obtained. Inductive data analysis using constant comparison methods was employed to identify patterns and themes within and across gender groups.

Definition and redesign of the extended substrate specificity of granzyme B

Granzyme B is a protease involved in the induction of rapid target cell death by cytotoxic lymphocytes. Definition of the substrate specificity of granzyme B allows for the identification of in vivo substrates in this process. By using the combinatorial methods of synthetic substrate libraries and substrate-phage display, an optimal substrate for granzyme B that spans over six subsites was determined to be Ile-Glu-Xaa-(Asp downward arrowXaa)-Gly, with cleavage of the Asp downward arrowXaa peptide bond. Granzyme B proteolysis was shown to be highly dependent on the length and sequence of the substrate, supporting the role of granzyme B as a regulatory protease. Arginine 192 was identified as a determinant of P3-Glu and P1-Asp substrate specificity. Mutagenesis of arginine 192 to glutamate reversed the preference for negatively charged amino acids at P3 to positively charged amino acids. The preferred substrate sequence matches the activation sites of caspase 3 and caspase 7 and thus is consistent with the role of granzyme B in activation of these proteases during apoptosis. The caspase substrate poly(ADP)-ribose polymerase is cleaved by granzyme B in a cell-free assay at two sites that resemble the granzyme B specificity determined by the combinatorial methods. Many caspase substrates contain granzyme B cleavage sites and are proposed as potential granzyme B targets, suggesting a redundant function with certain caspases.

Written language comprehension in younger and older adults

This study examined the effects of text genre and repeated reading on written language comprehension in younger (M = 21 years) and older (M = 72 years) healthy adults (N = 54). Participants verified four text-based statements (i.e., explicit, implicit, contradictory, and elaborated) after reading expository, narrative, and procedural texts. Verification accuracy was comparable for both age groups; however, text genre, statement-type, and repeated reading produced significant effects. Expository passages, explicit and implicit statements, and repeated reading yielded superior results. Procedural passages and contradictory and elaborated statements yielded less accurate results. Statement-types invoked multiple levels of cognitive representation across text genres and age groups. Overall, reading time was significantly faster for younger adults, and reading times were significantly faster for both age groups during the repeated reading trial. Text genre also influenced reading time, with expository passages read faster than narrative and procedural passages. These findings suggest the appreciable influences of text genre and repeated reading on measures of text processing and comprehension in healthy adults, irrespective of age.

Engineering enzyme specificity

Protein engineering is the application of knowledge to design and alter protein function and structure. Although powerful methods, from specific to random, have been developed for the redesign of protein architecture, their successful application is dependent on the information known about the protein. This database of information is providing a foundation for establishing rules that govern enzyme-substrate interactions.

Treatment of postprostatectomy urinary incontinence with behavioral methods

Prostate cancer is the most commonly diagnosed cancer in men. The radical prostatectomy is the treatment of choice for localized cancer; however, this surgery carries with it the potential complication of urinary incontinence postoperatively. The increasing number of radical prostatectomies each year will thus lead to a growing number of patients suffering from postprostatectomy urinary incontinence. According to the medical literature, the treatment of postprostatectomy incontinence is almost always limited to pharmacological or surgical therapy. Because of the failure of the standard treatment options, many men are left to live with their incontinence. The guidelines for the treatment of urinary incontinence recommend the use of behavioral methods as first-line treatment for stress and urge incontinence. The potential treatment of postprostatectomy incontinence with the use of behavioral methods has a promising future for the advanced practice nurse and for the men who are affected.

P-4 and RNKP-7, new granzyme-like serine proteases expressed in activated rat lymphocytes

Serine proteases (granzymes) in killer lymphocytes are required for lymphocyte cytotoxic granules to lyse target cells. Herein we report the development of a 3-step PCR cloning technique to amplify novel granzyme genes and two new rat granzymes are described. Degenerate oligonucleotide primers were designed based on sequence motifs selectively expressed in granzymes. These motifs flank "delta" regions that are unique for each granzyme. Total RNA of RNK-16 cells or activated splenocytes was amplified by reverse transcriptase-PCR to obtain cDNA fragments of several new granzymes. Gene-specific primers based on these delta regions were then used for 3'-RACE to obtain clones with the 3' gene ends. Reverse (antisense) delta-based or active site serine primers were used with a granzyme 5'-UTR primer to obtain clones extending to the 5' ends. Using this technique, two new cDNAs, RNKP-4 and RNKP-7, which encode granzymes of 248 and 241 amino acids, respectively, were cloned from activated lymphocytes. RNKP-4 is likely the rat equivalent of mouse granzyme C. RNKP-7 is most closely related to granzymes F and G. Modeling of the predicted proteins suggests large/polar P1 (Gln/Asn) specificity for RNKP-4 and large/hydrophobic P1 (e.g., Phe) specificity for RNKP-7. These specific protease activities were found in cytotoxic RNK-16 lymphocyte granules indicating that the two new genes may be translated and stored as active granzymes.

P-4 and RNKP-7, new granzyme-like serine proteases expressed in activated rat lymphocytes

Serine proteases (granzymes) in killer lymphocytes are required for lymphocyte cytotoxic granules to lyse target cells. Herein we report the development of a 3-step PCR cloning technique to amplify novel granzyme genes and two new rat granzymes are described. Degenerate oligonucleotide primers were designed based on sequence motifs selectively expressed in granzymes. These motifs flank "delta" regions that are unique for each granzyme. Total RNA of RNK-16 cells or activated splenocytes was amplified by reverse transcriptase-PCR to obtain cDNA fragments of several new granzymes. Gene-specific primers based on these delta regions were then used for 3'-RACE to obtain clones with the 3' gene ends. Reverse (antisense) delta-based or active site serine primers were used with a granzyme 5'-UTR primer to obtain clones extending to the 5' ends. Using this technique, two new cDNAs, RNKP-4 and RNKP-7, which encode granzymes of 248 and 241 amino acids, respectively, were cloned from activated lymphocytes. RNKP-4 is likely the rat equivalent of mouse granzyme C. RNKP-7 is most closely related to granzymes F and G. Modeling of the predicted proteins suggests large/polar P1 (Gln/Asn) specificity for RNKP-4 and large/hydrophobic P1 (e.g., Phe) specificity for RNKP-7. These specific protease activities were found in cytotoxic RNK-16 lymphocyte granules indicating that the two new genes may be translated and stored as active granzymes.

Dental erosion in a wine merchant: an occupational hazard?

This paper reports a case of dental erosion apparently caused by wine tasting. Dental erosion can cause extensive damage to the dentition, thereby creating a variety of complex restorative problems. Within the literature dental erosion has been attributed to many factors, but to date there are no documented cases specifically linking it with wine tasting. The dental professional is ideally placed to implement early preventive regimes which would make the occupation less damaging to the dentition.

Distinguishing detection from identification in subliminal auditory perception: a review and critique of Merikle's study

Assertions made by Merikle (1988) regarding audio subliminal messages were tested. Seventeen participants were presented subliminal messages embedded in a white-noise cover, and three signal-to-noise (S/N) detection ratios were examined. Participants were asked to guess message presence and message content, to determine subjective/objective thresholds. Results showed that participants were unable to identify target words presented in this audio subliminal stimulus format beyond chance levels.

Sociologic aspects of pregnancy

Increasingly, social factors are recognized as having a major impact on pregnancy, childbearing, and prenatal care. This review examines some of the more recent societal developments that have influenced health care for pregnant women. Although human gestation is a biologic phenomena, it exists with the social context of personal needs, family, and community of the pregnant women. This social fabric determines the perception, management, and outcome of that gestation. Significant influences to examine include pregnant women in the work force; malpractice concerns of health care providers; issues related to the cost of health care in pregnancy; the legal rights of the pregnant woman versus the legal rights of the fetus; pregnancy and occupational health; and the role of stress in pregnancy outcome.

Haptic asymmetries in persons with and without mental retardation

Adults with mild mental retardation and equal-MA children and adults without mental retardation were required to (a) tactually examine single letters, two-letter words, bigrams, and Chinese characters with their right or left index finger and (b) indicate whether a visually presented stimulus was the tactually examined stimulus by saying "same" or "different." The left hand was significantly better for "same" responses and the right hand, for "different" responses, suggesting that hemispheric processing is dependent on information-processing requirements rather than type of stimulus. A left hand advantage for "same" Chinese characters by the children and adults without mental retardation was due to an increase in right hand latencies rather than a decrease in left hand latencies, again suggesting that different types of analyses are employed by the two cerebral hemispheres. Adults with mental retardation had the poorest accuracy and slowest latencies for correct "different" responses and significantly less differentiation of "same" and "different" responses (A') for all stimulus types. They identified "same" letters, words, and bigrams significantly faster than Chinese characters with their left hand and showed a trend toward the differential processing of bigrams ("same" latencies) as a function of hand.

Diabetes mellitus in pregnancy

The Council on Scientific Affairs of the California Medical Association presents the following inventory of items of progress in obstetrics and gynecology. Each item, in the judgment of a panel of knowledgeable physicians, has recently become reasonably firmly established, both as to scientific fact and important clinical significance. The items are presented in simple epitome, and an authoritative reference, both to the item itself and to the subject as a whole, is generally given for those who may be unfamiliar with a particular item. The purpose is to assist busy practitioners, students, researchers, or scholars to stay abreast of these items of progress in obstetrics and gynecology that have recently achieved a substantial degree of authoritative acceptance, whether in their own field of special interest or another. The items of progress listed below were selected by the Advisory Panel to the Section on Obstetrics and Gynecology of the California Medical Association, and the summaries were prepared under its direction.

Universal self-care requisites as identified by homeless elderly men

1. Given the current economic climate, the number of homeless persons, and the nature of their needs, nurses must be prepared to facilitate movement of all homeless persons toward self-care. 2. Nurses can contribute to the self-care of homeless elderly men by recognizing and eliciting requisites, associated actions, and nursing interventions that reinforce meeting of needs. 3. Study results support Orem's proposition that universal self-care requisites are common to all individuals regardless of age, sex, developmental level, health state, or internal or external conditions. 4. A number of participant's statements used to formulate themes suggested a relationship to more than one category of universal self-care requisites, which suggests that the categories are not mutually exclusive.

Self-care actions of chronic schizophrenics associated with meeting solitude and social interaction requisites

Solitude becomes a way of life and social interaction a scarce commodity for many chronic schizophrenics who are in institutional settings. This article describes the self-care actions associated with meeting solitude and social interaction requisites as reported by 10 institutionalized chronic schizophrenics. Eighteen solitude self-care actions and 10 social interaction self-care actions emerged from the interview data. The solitude self-care actions clustered around two distinct categories: distancing and organizing. The social interaction self-care actions clustered around one category, managing situations. The implications of this study extend to anyone who is in the position of providing care and support to an individual diagnosed as a chronic schizophrenic. Additional research is suggested to increase the generalizability of the findings of this study and to isolate conditions related to Orem's (1985) sets of actions for maintenance of a balance between solitude and social interaction.