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PubMed2002

Differential stabilities of alkaline protease inhibitors from actinomycetes: effect of various additives on thermostability.

Exploiting the vast diversity of soil samples, we have isolated three actinomycetes strains producing alkaline protease inhibitors API-I (242 U/ml). API-II (116 U/ml) and API-III (186 U/ml). The inhibitors exhibited different properties in their molecular nature and in their pH and temperature stabilities. API-I and API-II were high molecular weight (> 10 kD) proteinaceous inhibitors whereas API-III was a low molecular weight inhibitor (< 10 kD). API-I and API-II exhibited stability over a pH range of 5-12 whereas API-III displayed a wide pH stability from 2-12. API-I was stable at 60 degrees C with a half-life of 2 h but API-II showed a half-life of 1 h at 45 degrees C. API-III exhibited the least thermal stability with complete loss of activity at 37 degrees C after 1 h. The stability of API-I, II and III at 65, 55 and 45 degrees C, respectively, was enhanced by the addition of various additives. Glycine (I M) offered complete protection to the three APIs. Polyethylene glycol 8000 (10 mM) prevented the thermoinactivation of API-I. In the presence of glycerol and sorbitol (10%) increase in stability by 40 60% of API-I and API-II was obtained. API-I offered enhanced stability to the target alkaline protease at 50 degrees C by forming a reversible enzyme-inhibitor complex.

Actinobacteria↗
PubMed1997

Prostate-specific antigen forms a complex with and cleaves alpha 1-protease inhibitor in vitro.

BACKGROUND: Complexes between prostate-specific antigen (PSA) and alpha 1-protease inhibitor (API) occur in serum and they are of potential interest in the diagnosis of prostate cancer. Pure PSA-API complexes are needed for development of specific assays, but complex formation has not earlier been achieved in vitro. METHODS: PSA was incubated with an excess of API at 37 degrees C. Complexes formed were quantitated by an immunofluorometric assay using antibodies to PSA and API. The products were further characterized by SDS-PAGE, immunoblotting and amino-acid sequencing. PSA-API was purified by gel filtration and immunoaffinity chromatography. RESULTS: PSA formed an SDS-stable 80-kDa one-to-one complex with API. The rate of formation of PSA-API was slow compared to that of PSA-alpha 2-macroglobulin (A2M) or PSA-alpha 1-antichymotrypsin (ACT), and only about 15% of PSA complexed with a 5-fold molar excess of API at 37 degrees C in 7 days. A major part of API was cleaved between 358-Met and 359-Ser, causing loss of inhibitory activity. PSA-API formed in vitro was purified by gel filtration and immunoaffinity chromatography with anti-PSA antibody. After incubation for 7 days at 37 degrees C, 30-40% of the complex had dissociated causing release of active PSA and proteolytically cleaved inactive API. The dissociation was accelerated in the presence of serum, and released PSA complexed with A2M and ACT. CONCLUSIONS: PSA forms a complex with API in vitro, but the reaction is slow and part of the API is cleaved. Complex formation is reversible and released PSA is enzymatically active, whereas API is inactivated. Purified PSA-API will facilitate development of quantitative immunoassays for this complex.

Chromatography, Affinity↗
PubMed2001

Tuning compounds for electrospray ionization/in-source collision-induced dissociation and mass spectra library searching.

Tuning compounds for positive and negative electrospray ionization (ESI) were tested for the tuning of in-source collision-induced dissociation (ESI/CID) with three types of SCIEX API instruments (API 365, 2000 and 3000) in the single-quadrupole mode. The vacuum interfaces of these instruments differ slightly in geometry, but the principles of ionization and solvent evaporation by nebulizer and curtain gases, orifice and skimmer are identical. For comparison of in-source CID, breakdown curves of haloperidol, paracetamol, metronidazole and metamizole were acquired by increasing the orifice voltages. The API 2000 and 3000 required higher orifice voltages than did the API 365 to induce a similar degree of fragmentation of the protonated or deprotonated molecules to characteristic fragment ions. This increase of orifice voltage could be demonstrated with each of the four compounds tested by a shift of the maxima of the breakdown curves to higher orifice voltages. A procedure with three collision energy (CE) levels for drug identification with a mass spectra library set up with an API 365 therefore required an adjustment of the orifice voltages to higher values when being transferred to an API 2000 or API 3000. The corresponding orifice voltages for the three instruments were 20/50/80 V (API 365), 30/90/130 V (API 2000) and 40/80/120 V (API 3000). However, a change in orifice voltage of +/-10 V (with the API 2000 and 3000) hardly influenced the fit values of a library search for each single CE level. For adjusting orifice voltages with different instruments, a tuning procedure with haloperidol and paracetamol is presented. With this tuning procedure an ESI/CID mass spectra library set up for API 365 and API 150 could also be used for drug identification with an API 2000 and an API 3000 with good library search results.

Chromatography, High Pressure Liquid↗
PubMed1987

Serum alpha-1 proteinase inhibitor in advanced cancer: mass variants and functionally inert forms.

In 1984, we reported that while immunoreactive levels of serum alpha-1 proteinase inhibitor (API) increased significantly in nine patients with advanced solid tumors, the functional activity of the inhibitor, as measured by the serum trypsin inhibitory capacity, did not increase proportionately. This suggested that a portion of the circulating API was functionally inert. We have now assayed immunoreactive titers and trypsin inhibitory capacity of serum API of 49 patients with advanced carcinomas and 27 healthy controls. Immunoreactive levels of API (expressed as percentage of normal pooled serum which was taken as 100%) in cancer subjects were significantly elevated as compared to normals (mean +/- SE: 233 +/- 9.0% versus 102 +/- 2.0%, P less than 0.05). Although the trypsin inhibitory capacity of the cancer group (16.0 +/- 0.9 units/ml) was significantly elevated (P less than 0.05) as compared to normals (9.9 +/- 0.1 units/ml), this increase was less than that in the immunoreactive titer of API, suggesting the existence of functionally inert API in serum. The fraction of API which was functionally active in this group of cancer patients was 71.0 +/- 3.0% which was significantly less than the normal 98.0 +/- 2.0% (P less than 0.05). In 12 patients followed serially, both immunoreactive levels of API and the trypsin inhibitory capacity increased significantly at the time of clinical progression of disease. There was a significant correlation between increasing absolute granulocyte count and increasing trypsin inhibitory capacity (correlation coefficient 0.66; P less than 0.001). Neither disease progression nor increasing granulocyte count, however, was associated with increasing proportion of functionally inactive API. The inactive form of API had the same molecular weight as the native molecule as shown by gel permeation chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis/Western blot analysis of cancer sera. Therefore, the inactive form was not due to a complex between API and a tumor-derived protease or to proteolytic fragmentation of the native API. Elastase inhibitory capacity of cancer sera with subactive API was essentially identical with trypsin inhibitory capacity indicating that the active site methionine was not oxidized in the inert API. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis/Western blot analysis showed that both normal and cancer serum API existed as two mass variants, at Mr 58,000 and 56,000. Both variants formed complexes with elastase and were functionally active.

Blood Proteins↗
PubMed2004

Subsite-specific colorectal cancer incidence rates and stage distributions among Asians and Pacific Islanders in the United States, 1995 to 1999.

OBJECTIVE: This study examined subsite-specific colorectal cancer incidence rates and stage distributions for Asians and Pacific Islanders (API) and compared the API data with data for Whites and African Americans. METHODS: Data included 336,798 invasive colorectal cancer incident cases for 1995 to 1999 from 23 population-based central cancer registries, representing about two thirds of API population in the United States. Age-adjusted rates, using the 2000 U.S. standard population, and age-specific rates and stage distributions were computed by anatomic subsite, race, and gender. All rates were expressed per 100,000. SEs and rate ratios were calculated for rate comparison. A significance level of 0.05 was used for all analyses. RESULTS: Overall, age-adjusted colorectal cancer incidence rates were significantly lower in API than in Whites and African Americans across anatomic subsites, particularly for proximal colon cancer in which rates were 40% to 50% lower in API males and females. Exception to this pattern was the significantly (10%) higher rectal cancer incidence rate in API males than in African American males. The incidence patterns by anatomic subsite within API differed from those of Whites and African Americans. Among API, the rate of rectal cancer (19.2 per 100,000) was significantly higher than the rates of proximal (15.2 per 100,000) and distal (17.7 per 100,000) colon cancers in males, with little variations in rates across anatomic subsites in females. In contrast, among White and African American males and females, proximal colon cancer rates were over 25% higher than the rates of distal colon and rectal cancers. Increases in age-specific rates with advancing age were more striking for proximal colon cancer than for distal colon and rectal cancers in Whites and African Americans, while age-specific rates were very similar for different subsites in API with parallel increases with advancing age, especially in API males. Similar to Whites and African Americans, in API, proximal colon cancers (32% to 35%) were also less likely to be diagnosed with localized stage compared with distal colon (38% to 42%) and rectal (44% to 52%) cancers. CONCLUSION: The patterns of subsite-specific colorectal cancer incidence in API, especially API males, differ from those of Whites and African Americans. Similar to Whites and African Americans, lower percentage of localized disease in API for proximal colon cancer than for distal colon and rectal cancers was also observed.

Adult↗
PubMed2006

Incidence of esophageal and gastric carcinomas among American Asians/Pacific Islanders, whites, and blacks: subsite and histology differences.

BACKGROUND: The authors examined subsite-specific and histology-specific esophageal and gastric carcinoma incidence patterns among the Asians/Pacific Islander (API) population in the United States and compared them with those among whites and blacks. METHODS: Data on newly diagnosed esophageal and gastric carcinomas during 1996-2000 were obtained from 24 population-based central cancer registries, representing approximately 80% of the API population in the United States. Age-adjusted rates, using the 2000 United States standard population, and age-specific rates were computed by anatomic subsite, histology, race, and gender. The difference in the age-adjusted rates between APIs and other races were examined using the two-tailed z statistic. RESULTS: Greater than 75% of esophageal carcinomas among APIs, both males and females, were squamous cell carcinoma. Adenocarcinoma accounted for <20% of all esophageal carcinomas. This pattern was similar to that among blacks but was completely opposite to that among whites. The rate of esophageal squamous cell carcinoma was 81% higher among API males compared with white males, but it was 64% less compared with black males. The rates of esophageal adenocarcinoma were significantly lower among APIs than among both whites and blacks both males and females. The majority of gastric carcinomas among APIs were noncardia adenocarcinoma, whereas cardia adenocarcinoma accounted for only 11% of gastric carcinomas among API males and 6% of gastric carcinomas among API females. The age-adjusted incidence rate of cardia adenocarcinoma was 23% lower among API males compared with white males, but it was 26% higher compared with black males. In contrast, the rates of noncardia adenocarcinoma among APIs were approximately 3.7 times the rate among whites for both males and females and 33% higher than the rate among blacks. CONCLUSIONS: Subsite-specific and histology-specific incidence patterns of esophagogastric carcinoma among APIs differ from those among whites and blacks. The reasons for significantly higher rates of noncardia adenocarcinoma among APIs compared with whites and blacks need further investigation.

Adenocarcinoma↗
PubMed1996

Mononuclear Titanium Complexes That Contain Aminopyridinato Ligands.

2-(Methylamino)pyridine (Me-APy-H), 2-anilinopyridine (Ph-APy-H), and 4-methyl-2-((trimethylsilyl)amino)pyridine (TMS-APy-H) were used to synthesize mononuclear monochloro complexes that contain two or three such aminopyridines as strained amido ligands. The reaction of 2 or 3 equiv of in situ generated lithium aminopyridinate with TiCl(4)(THF)(2) or TiCl(4) afforded just in the case of Me-APy-H a red crystalline product (Me-APy)(3)TiCl (1a) but in unacceptably low yield. An alternative way to synthesize 1a and (Ph-APy)(3)TiCl (1b) is amine elimination, starting from mixed chlorodimethylamido complexes like (Me(2)N)(3)TiCl or (Me(2)N)(2)TiCl(2). The reaction of (Me(2)N)(3)TiCl with 2 equiv of Me-APy-H, Ph-APy-H or TMS-APy-H afforded (Me-APy)(2)Ti(NMe(2))Cl (2a), (Ph-APy)(2)Ti(NMe(2))Cl (2b), or (TMS-APy)(2)Ti(NMe(2))Cl (2c). These compounds represent novel unusual highly nitrogen-coordinated titanium complexes. X-ray diffraction studies of 1a established its monomeric structure as having a disturbed pentagonal bipyramidal coordination geometry. X-ray crystal structure investigations of 2a-c proved these compounds to be monomeric with a slightly distorted octahedral coordination geometry. The eta(2) binding mode of the strained aminopyridinato ligands is discussed in comparison to the related amidinato ligand system by averaging bond distances and angles of the determined structures. The N(Py)-C-N(amido) angle of 108(1) degrees instead of the desired 120 degrees indicates the highly strained tweezers-like bonding mode. The Ti-N(Py) distances vary within the known range. The Ti-N(amido) distances are more than 0.1 Å longer than the expected values and indicate weak amido bonds. Variable-temperature NMR investigations of complex 2c are indicative of exchange processes which proceed most likely via tetrahedral transition states. Crystallographic data (distances, Å; angles, deg): 1a, C(18)H(21)ClN(6)Ti, a = 9.313(1), b = 10.277(1), c = 11.302(1), alpha = 98.15(1), beta = 108.28(1), gamma = 102.98(1), triclinic, P&onemacr;, Z = 2; 2a, C(14)H(20)ClN(5)Ti, a = 8.725(1), b = 9.258(1), c = 10.778(1), alpha = 83.288(7), beta = 79.977(9), gamma = 78.766(8), triclinic, P&onemacr;, Z = 2; 2b, C(24)H(24)ClN(5)Ti, a = 17.652(3), b = 7.959(1), c = 18.017(3), beta = 111.37(1), monoclinic, P2(1)/a, Z = 4; 2c, C(20)H(36)ClN(5)Si(2)Ti, a = 10.786(1), b = 14.053(1), c = 18.144(1), beta = 97.06(1), monoclinic, P2(1)/c, Z = 4.

Journal Article↗
PubMed2001

Diabetic rats transplanted with adult porcine islets and immunosuppressed with cyclosporine A, mycophenolate mofetil, and leflunomide remain normoglycemic for up to 100 days.

BACKGROUND: Transplantation of adult porcine islets (APIs) offers a possible means of treating diabetes. However, isolating APIs has been notoriously difficult. Furthermore, islet xenograft rejection must be prevented. MATERIALS AND METHODS: APIs were isolated by a modified automated method. API quality was assessed by static glucose stimulation (SGS), by transplantation to diabetic nude mice and by intraperitoneal glucose tolerance tests (IPGTTs). The morphologic characteristics of API xenograft rejection in rats were studied immunohistochemically. Furthermore, APIs were transplanted to diabetic rats that were either left untreated or immunosuppressed with cyclosporine A (CsA), mycophenolate mofetil (MMF) and leflunomide (LEF). B-glucose and porcine C-peptide levels were monitored and grafts were studied morphologically. RESULTS: Large numbers of APIs were isolated. At SGS, insulin release increased significantly. All nude mice transplanted with APIs were normoglycemic within 24 hr and remained so for up to 1 year. During IPGTTs, B-glucose levels were rapidly regulated to porcine levels. In untreated rats, API xenografts were destroyed within 6 days by a cellular infiltrate consisting mainly of macrophages. In untreated diabetic rats normoglycemia was sustained for 5.5+/-0.3 days. Rats immunosuppressed with CsA+MMF+LEF remained normoglycemic for 59.6+/-11.3 days. In 3 of 11 rats, normoglycemia was sustained for up to 101 days. Porcine C-peptide was detected in serum. At recurrence of hyperglycemia, many mononuclear cells were found close to the xenografts. However, only occasional cells infiltrated the grafts and many APIs were intact. CONCLUSIONS: Well-functioning APIs can be isolated in large numbers. API xenografts can be protected from rejection and can maintain an adequate function for up to 100 days, in rats immunosuppressed with CsA+MMF+LEF.

Animals↗
PubMed2006

Theoretical and practical approaches for prediction of drug-polymer miscibility and solubility.

PURPOSE: Crystallization of drugs formulated in the amorphous form may lead to reduced apparent solubility, decreased rate of dissolution and bioavailability and compromise the physical integrity of the solid dosage form. The purpose of this work was to develop thermodynamic approaches, both practical and theoretical, that will yield a better understanding of which factors are most important for determining the ability of polymers to stabilize amorphous active pharmaceutical ingredients (API). MATERIALS AND METHODS: Lattice based solution models were used to examine miscibility criteria in API-polymer blends. Different methods were used to estimate the Flory-Huggins interaction parameter for model API-polymer systems consisting of felodipine or nifedipine with poly(vinylpyrrolidone) (PVP). These were melting point depression and determination of solubility parameters using group contribution theory. The temperature and enthalpy of fusion of crystalline API alone and the fusion temperature of the API in the presence of the polymer were measured by differential scanning calorimetry. The resultant thermal data were used to estimate the reduced driving force for crystallization and the solubility of the API in the polymer. RESULTS: Flory-Huggins theory predicts that, for typical API-polymer systems, the entropy of mixing is always favorable and should be relatively constant. Due to the favorable entropy of mixing, miscibility can still be achieved in systems with a certain extent of unfavorable enthalpic interactions. For the model systems, interaction parameters derived from melting point depression were negative indicating that mixing was exothermic. Using these interaction parameters and Flory-Huggins theory, miscibility was predicted for all compositions, in agreement with experimental data. A model was developed to estimate the solubility of the API in the polymer. The estimated solubility of the model APIs in PVP is low suggesting that kinetic rather than thermodynamic stabilization plays a significant role in inhibiting crystallization. CONCLUSIONS: The thermodynamics of API-polymer systems can be modeled using solution based theories. Such models can contribute towards providing an understanding of the compatibility between API and polymer and the mechanisms of physical stabilization in such systems.

Algorithms↗
PubMed1996

Identification of a cytoplasm to vacuole targeting determinant in aminopeptidase I.

Aminopeptidase I (API) is a soluble leucine aminopeptidase resident in the yeast vacuole (Frey, J., and K.H. Rohm. 1978. Biochim. Biophys. Acta. 527:31-41). The precursor form of API contains an amino-terminal 45-amino acid propeptide, which is removed by proteinase B (PrB) upon entry into the vacuole. The propeptide of API lacks a consensus signal sequence and it has been demonstrated that vacuolar localization of API is independent of the secretory pathway (Klionsky, D.J., R. Cueva, and D.S. Yaver. 1992. J. Cell Biol. 119:287-299). The predicted secondary structure for the API propeptide is composed of an amphipathic alpha-helix followed by a beta-turn and another alpha-helix, forming a helix-turn-helix structure. With the use of mutational analysis, we determined that the API propeptide is essential for proper transport into the vacuole. Deletion of the entire propeptide from the API molecule resulted in accumulation of a mature-sized protein in the cytosol. A more detailed examination using random mutagenesis and a series of smaller deletions throughout the propeptide revealed that API localization is severely affected by alterations within the predicted first alpha-helix. In vitro studies indicate that mutations in this predicted helix prevent productive binding interactions from taking place. In contrast, vacuolar import is relatively insensitive to alterations in the second predicted helix of the propeptide. Examination of API folding revealed that mutations that affect entry into the vacuole did not affect the structure of API. These data indicate that the API propeptide serves as a vacuolar targeting determinant at a critical step along the cytoplasm to vacuole targeting pathway.

Amino Acid Sequence↗
PubMed2000

Celery allergens in patients with positive double-blind placebo-controlled food challenge.

BACKGROUND: Recently, for the first time, allergy to celery was confirmed by double-blind placebo-controlled food challenge (DBPCFC). Api g 1, Api g 4, cross-reactive carbohydrate determinants (CCD), and a 60 kDa allergen have been described as celery allergens. OBJECTIVE: To get insights in IgE responses of patients with a positive DBPCFC to celery tuber (celeriac) compared with patients with a negative challenge test. METHODS: Specific IgE to native and heated celery tuber and to recombinant Api g 1, the major celery allergen, were determined by enzyme allergosorbent test and immunoblotting. IgE binding to Api g 1, Api g 4, and CCD was confirmed by inhibition experiments that used recombinant Api g 1, recombinant Api g 4, pure N-glycans, and extracts of celeriac, lychee fruit, and pollens of birch, mugwort, and timothy grass as inhibitors. RESULTS: Immunoblotting with sera from 22 patients with a positive DBPCFC to celeriac confirmed the presence of known allergenic structures: The major allergen Api g 1 (16 kDa) was recognized by IgE from 13 of 22 patients (59%). Another major allergen was CCD, determined by IgE reactivity in 12 of 22 patients (55%). Celery profilin, Api g 4, was recognized by IgE from 5 of 22 patients (23%). CONCLUSION: Our DBPCFC-positive patients exclusively presented IgE to known celery allergens, although the prevalences were slightly different than were previously reported. No obvious differences were found in patients with positive IgE antibody but negative challenge test. IgE binding to all 3 structures in celeriac extract was inhibited by birch pollen extract, whereas mugwort pollen extract could only inhibit IgE reactivity to Api g 4 and CCD. Inhibition experiments with a purified carbohydrate moiety clearly showed that the IgE epitope mannose-xylose-fucose-glycan (Manalpha1-6[Xylbeta1-2]Manbeta1-4GlcNAcbeta1-4[ Fucalpha1-3]GlcNAc) or a closely related structure is present in celeriac extract and is important in patients with clinical allergy to celery.

Administration, Oral↗
PubMed1999

Measurement of the complex between prostate-specific antigen and alpha1-protease inhibitor in serum.

BACKGROUND: Prostate-specific antigen (PSA) occurs in serum both free and in complex with protease inhibitors. The complex with alpha1-antichymotrypsin (ACT) is the major form in serum, and the proportion of PSA-ACT is higher in prostate cancer (PCa) than in benign prostatic hyperplasia (BPH). PSA also forms a complex with alpha1-protease inhibitor (API) in vitro, and the PSA-ACT complex has been detected in serum from patients with prostate cancer. The aim of the present study was to develop a quantitative method for the determination of PSA-API and to determine the serum concentrations in patients with PCa and BPH. METHODS: The assay for PSA-API utilizes a monoclonal antibody to PSA as capture and a polyclonal antibody to API labeled with a Eu-chelate as a tracer. For calibrators, PSA-API formed in vitro was used. Serum samples were obtained before treatment from 82 patients with PCa, from 66 patients with BPH, and from 22 healthy females. RESULTS: The concentrations of PSA-API are proportional to the concentrations of total PSA. PSA-API comprises 1.0-7.9% (median, 2.4%) of total immunoreactive PSA in PCa and 1.3-12.2% (median, 3.6%) in BPH patients with serum PSA concentrations >4 microgram/L. In patients with 4-20 microgram/L total PSA, the proportion of PSA-API serum is significantly higher in BPH (median, 4.1%) than in PCa (median, 3. 2%; P = 0.02). CONCLUSIONS: The proportion of PSA-API in serum is lower in patients with PCa than in those with BPH. These results suggest that PSA-API is a potential adjunct to total and free PSA in the diagnosis of prostate cancer.

Electrophoresis, Polyacrylamide Gel↗
PubMed2006

The use of rabbit polyclonal antibodies to assess neoantigenicity following viral reduction of an alpha-1-proteinase inhibitor preparation.

The objective of this study was to determine whether the viral reduction processes of nanofiltration and solvent/detergent treatment used in the manufacture of alpha-1 proteinase inhibitor (API) cause neoantigenic changes. Polyclonal antibodies were raised in rabbits against the treated API and quantitatively absorbed with an affinity column containing API that had not undergone viral reduction treatment. Antibodies before and after absorption were measured in a validated ELISA using the immunogen for antibody capture. Antibodies against novel API epitopes were not found after antiserum from rabbits inoculated with treated API was absorbed with untreated API. A positive control, consisting of serum obtained from rabbits inoculated with trinitrophenylated API, showed substantial amounts of measurable antibody following absorption with untreated API. The results suggest that the viral reduction process used does not result in the creation of API neoantigens.

Animals↗
PubMed2001

Etiology and prevention of substance use among Asian American youth.

Among populations identified by the U.S. Bureau of the Census, it is anticipated that the Asian/Pacific Islander (API) population will experience the greatest change between 1990 and 2050 (U.S. Bureau of the Census. [1996, February]. Current population reports. Series P25-1130. Washington, DC: U.S. Government printing office). Limited studies focus on APIs as a racial group and still fewer disaggregate samples to specific ethnic Asian subgroupings. This paper begins with definitions of the API communities, then examines rates of adolescent drug use, risk and protective factors, and preventive intervention effectiveness focused on API communities. The limited epidemiological data suggest that in general, APIs are at a relatively lower risk for drug use than youth from most other ethnic groups. However, the available data also suggest that use may not be as low as generally assumed with rates for alcohol use, smoking, and some illicit drugs being equal to or exceeding those of African Americans and European Americans. Despite the paucity of available data on particular Asian subgroups, the available data demonstrate that there are differences among API subgroups, underscoring the importance of identifying Asian subgroups when studying substance use and when planning prevention and treatment. The limited data examining the etiology of drug use across API subgroups suggests that some of the risk and protective factors derived from majority based research may also be predictors for these populations. These data support the utility of examining the generalizability of existing tested prevention approaches among different API communities. Finally, further efforts should be made to encourage and support the evaluation of community-based programs that already target and deliver services to API youth.

Adolescent↗
PubMed2005

Genetic mapping of aphicarus -- a sex-linked locus controlling a wing polymorphism in the pea aphid (Acyrthosiphon pisum).

We have initiated research to determine the genetic basis of a male wing polymorphism in the pea aphid Acyrthosiphon pisum (Hemiptera: Aphididae). Previous studies showed that this polymorphism is controlled by a single biallelic locus, which we name aphicarus (api), on the X chromosome. Our objectives were to confirm that api segregates as a polymorphism of a single gene on the X chromosome, and to obtain molecular markers flanking api that can be used as a starting point for high-resolution genetic and physical mapping of the target region, which will ultimately allow the cloning of api. We have established an F2 population segregating for api and have generated X-linked AFLP markers. The segregation pattern of api in the F2 population shows that the male wing polymorphism segregates as a polymorphism of a single gene, or set of closely linked genes on the X chromosome. Using a subset of 78 F2 males, we have constructed a linkage map of the chromosomal region encompassing api using seven AFLP markers. The map spans 74.1 cM and we have mapped api to an interval of 10 cM. In addition, we confirmed X linkage of our AFLP markers and api by using one X-linked marker developed in an earlier study. Our study presents the first mapping of a gene with known function in aphids, and the results indicate that target gene mapping in aphids is feasible.

Animals↗
PubMed2004

Influence of the size of micronized active pharmaceutical ingredient on the aerodynamic particle size and stability of a metered dose inhaler.

Pharmaceutical inhalers are often used to treat pulmonary diseases. Only active pharmaceutical ingredient (API) particles from these inhalers that are less than approximately 5 microm are likely to reach the lung and be efficacious. This study was designed to investigate the impact of micronized API particle size on the aerodynamic particle size distribution (PSD) profile and the particle size stability of a suspension metered dose inhaler (MDI) containing propellant HFA-227 (1,1,1,2,3,3,3 heptafluoropropane) and a corticosteroid. The median API particle size ranged from 1.1 microm to 1.8 microm (97% to 70% of particles <3 microm, respectively). This study showed that increasing the particle size of the API used to manufacture a suspension MDI product increased the aerodynamic PSD of the MDI product. Furthermore, upon storage of the MDI product under temperature cycling conditions, samples containing larger-size API particles were less stable with respect to their aerodynamic PSD than those with smaller-size API particles. It was found that size-dependent particle growth and/or aggregation of the suspended API may be occurring as a result of temperature cycling. In conclusion, this study has shown that the particle size of the raw API impacts the properties and stability of the emitted aerosol spray. Based on the findings from this study, it is recommended that the API particle size be carefully controlled in order to meet specifications set for the finished MDI product.

Metered Dose Inhalers↗
PubMed1986

Islet-cell hyperplasia in genetic deficiency of alpha-1-proteinase inhibitor.

By light microscopy and immunoperoxidase methods, morphology and distribution of alpha-1-proteinase inhibitor (Api) cells in the pancreatic islets were studied in seven patients with and in 17 patients without periodic acid-Schiff-positive, diastase-resistant globules in the liver. Five of the seven patients with liver globules had cirrhosis and emphysema, suggesting genetic deficiency of Api, which was confirmed in four by pi phenotyping (blood from one patient was not available). The two remaining patients had only a mild degree of liver fibrosis and mild emphysema and showed a normal MM phenotype. Islet cell hyperplasia and an increased population of Api cells were observed in all five patients with genetic deficiency, compared with the 17 patients without Api deficiency. These morphologic changes were more pronounced in the one homozygous patient than in the heterozygous patients. Nesidioblastosis, ductular proliferation, and atypia of insular cells were seen only in patients with an abnormal phenotype. The increased amount of Api in the islets in the genetic deficiency state may be due to hyperplasia and hypertrophy of Api cells or due to storage of abnormal Api in the preexisting Api cells. The exact stimulus for islet cell hyperplasia and proliferation of Api cells is still unknown.

Aged↗
PubMed1991

Can Doppler pressure measurement replace "exclusion" arteriography in the diagnosis of occult extremity arterial trauma?

Although highly accurate, contrast arteriography is a costly, invasive, and time-consuming method to rule out occult arterial damage in injured extremities. Accordingly the authors assessed the sensitivity and specificity of Doppler-derived arterial pressure measurements in trauma victims undergoing evaluation for possible extremity arterial damage. Arterial pressure index (API) was calculated (Doppler arterial pressure distal to injury/Doppler arterial pressure in uninvolved arm), but not used in clinical decision making in 100 consecutive injured limbs in 93 trauma victims. All patients then underwent contrast arteriography. Twenty limbs had an API less than 0.90 and an abnormal arteriogram, whereas 75 had both a normal API and a normal contrast study. One limb had a significant angiographic abnormality with an API greater than 0.90; two others had API less than 0.90 but normal arteriograms. Two limbs with a normal API had false-positive arteriograms. When compared with arteriography, an API less than 0.90 had a sensitivity of 87% and a specificity of 97% for arterial disruption in this series. Sensitivity and specificity rose to 95% and 97% when API was compared with clinical outcome. In the absence of obvious signs of arterial injury, API may be a reasonable substitute for screening arteriography in the traumatized extremity, particularly if close follow-up observation can be assured.

Adolescent↗