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Process analytical technology case study: part II. Development and validation of quantitative near-infrared calibrations in support of a process analytical technology application for real-time release.

This article is the second of a series of articles detailing the development of near-infrared (NIR) methods for solid dosage-form analysis. Experiments were conducted at the Duquesne University Center for Pharmaceutical Technology to demonstrate a method for developing and validating NIR models for the analysis of active pharmaceutical ingredient (API) content and hardness of a solid dosage form. Robustness and cross-validation testing were used to optimize the API content and hardness models. For the API content calibration, the optimal model was determined as multiplicative scatter correction with Savitsky-Golay first-derivative preprocessing followed by partial least-squares (PLS) regression including 4 latent variables. API content calibration achieved root mean squared error (RMSE) and root mean square error of cross validation (RMSECV) of 1.48 and 1.80 mg, respectively. PLS regression and baseline-fit calibration models were compared for the prediction of tablet hardness. Based on robustness testing, PLS regression was selected for the final hardness model, with RMSE and RMSECV of 8.1 and 8.8 N, respectively. Validation testing indicated that API content and hardness of production-scale tablets is predicted with root mean square error of prediction of 1.04 mg and 8.5 N, respectively. Explicit robustness testing for high-flux noise and wavelength uncertainty demonstrated the robustness of the API concentration calibration model with respect to normal instrument operating conditions.

Computer Systems↗

Interspecific variation in beeswax as a biological construction material.

Beeswax is a multicomponent material used by bees in the genus Apis to house larvae and store honey and pollen. We characterized the mechanical properties of waxes from four honeybee species: Apis mellifera L., Apis andreniformis L., Apis dorsata L. and two subspecies of Apis cerana L. In order to isolate the material effects from the architectural properties of nest comb, we formed raw wax in to right, circular cylindrical samples, and compressed them in an electromechanical tensometer. From the resulting stress-strain curves, values for yield stress, yield strain, stress and strain at the proportional limit, stiffness, and resilience were obtained. Apis dorsata wax was stiffer and had a higher yield stress and stress at the proportional limit than all of the other waxes. The waxes of A. cerana and A. mellifera had intermediate strength and stiffness, and A. andreniformis wax was the least strong, stiff and resilient. All of the waxes had similar strain values at the proportional limit and yield point. The observed differences in wax mechanical properties correlate with the nesting ecology of these species. A. mellifera and A. cerana nest in cavities that protect the nest from environmental stresses, whereas the species with the strongest and stiffest wax, A. dorsata, constructs relatively heavy nests attached to branches of tall trees, exposing them to substantially greater mechanical forces. The wax of A. andreniformis was the least strong, stiff and resilient, and their nests have low masses relative to other species in the genus and, although not built in cavities, are constructed on lower, often shielded branches that can absorb the forces of wind and rain.

Animals↗

Cytokine regulatory effects on alpha-1 proteinase inhibitor expression in NOD mouse islet endothelial cells.

Human microvascular islet endothelial cells (IEC) exhibit specific morphological and functional characteristics that differ from endothelia derived from other organs. One of these characteristics is the expression of alpha-1 proteinase inhibitor (Api). In this study, we observed its expression in nonobese diabetic (NOD) mouse IEC, in relation to the occurrence of type 1 diabetes and in response to cytokines, namely IL-1 beta and IL-10. In addition, IL-10-deficient NOD mice as well as IL-10 transgenic NODs were studied. Results have demonstrated that Api expression is: (i) highly specific for IEC in NOD mouse islets, as for humans; (ii) linked to the occurrence of early type 1 diabetes, and iii) strongly modulated by Th1 and Th2 cytokines. In fact, Api mRNA found in pre-diabetic NOD animals is significantly reduced when they become hyperglycemic and disappears by 25 weeks of age, when mice are diabetic. Moreover, Api mRNAs are never seen in nondiabetic controls. Furthermore, in cultured NOD IEC, Api expression is downregulated by the addition of IL-1 beta and is upregulated by IL-10; it is always absent in IL-10-deficient NOD mice and overexpressed in IL-10 transgenic NODs, thus further supporting that this cytokine upregulates Api expression.

Animals↗

Population genetic studies in bees (APIDAE, Hymenoptera). I. Genetic load.

Three populations of Apis mellifera each predominantly of a different subspecies (mellifera, ligustica and adansonii) and 7 species of stingless bees (Meliponinae, Apidae) were manipulated for applying the MORTON, CROW & MULLER's methodology in order to estimate the lethal equivalents (B) of each population. A total of 249 queens were used, 27 being meliponids and 222 Apis mellifera. The populations of Apis have a B that does not differ significantly when they are compared to each other (1.29, 1.36, 1.32) and the balanced average equals 1.33. When the x-alleles are not considered, this balanced value is 0.262. The figures for B in the seven species of stingless bees ranged between 0.104 and 0.159 with balanced average of 0.132. The main reason for this smaller load in meliponids may rest in their effective population numbers, which are smaller than those of Apis. The average mortality for diploid females (0.141) and for haploid males (0.163) allows the estimation of the total elimination (sigma E = 0.073). Since for haplo-diploid systems the total mutation rate is sigma mu = 2 sigma E divided by 3 the figure 0.048 is obtained. Since about 15% of the genes in Apis mellifera are sex limited, this value of sigma mu should be added of 0.0072 (that is 0.15 X 0.048) and then, the total mutation rate becomes 0.055. Using a quite different method, the one by MORTON, CROW & MULLER, the figure 0.076 was obtained. If a mutation rate of 10(-5) is assumed, the number of genes in Apis mellifera that can make a contribution to the genetic load would vary between 5,500 and 7,600.

Animals↗

[Relationships of bee population fluctuation and distribution with natural environment in Anhui province].

In 2002 to approximately 2004, an investigation was made on the bee population dynamics and its relationships with the ecological environment in four ecological regions of Anhui Province. The results indicated that in the mountainous areas of south and west Anhui, there were 46 and 37 species of nectariferous plants, and the distribution density of Apis cerena cerena population was 2.01 and 1.95 colony x km(-2), respectively. In Jianghuai area and Huaibei plain, there were 17 and 12 species of nectariferous plants, which had concentrated and short flowering period and fitted for Apis mellifera Ligustica oysterring and producing, and the distribution density of Apis cerena cerena population was 0. 06 and 0. 02 colony x km(-2), respectively. Bee population fluctuation and distribution was affected by wasp predation. The breeding proportion of Apis cerena cerena to local apis population was 41.5%, 36.8%, 3.1% and 1.1%, and that of Apis mellifera Ligustica was 58.5%, 63.2%, 96.9% and 98.9% in the mountainous areas of south and west Anhui, Jianghuai area, and Huaibei plain, respectively.

Animals↗

Non-invasive vascular tests reliably exclude occult arterial trauma in injured extremities.

We evaluated the ability of noninvasive vascular tests to exclude clinically significant occult arterial damage in injured extremities. In a preliminary study, a Doppler arterial pressure index (API) (the systolic AP in the injured extremity divided by the AP in an uninvolved arm) of less than 0.90 was found to have sensitivity and specificity of 95% and 97%, respectively, for major arterial injury. The negative predictive value for an API greater than 0.90 was 99%. Because these values suggested that noninvasive vascular tests might effectively be substituted for "exclusion" arteriography in patients at risk for silent extremity arterial injuries, we then conducted a trail in which arteriography was performed in extremity trauma victims only when the API was less than 0.90. Among 100 traumatized limbs (84 penetrating, 16 blunt) in 96 consecutive patients, 16 of 17 limbs (94%) with an API less than 0.90 had positive arteriographic findings, and seven underwent arterial reconstruction. Among 83 limbs with an API greater than 0.90, followup (including duplex scanning in 64 limbs) revealed five minor arterial lesions (four pseudoaneurysms, one arteriovenous fistula) but no major injuries. Arteriograms for extremity trauma fell from 14% to 5.2% of all angiographic studies performed (p less than 0.001, Chi-square). These studies suggest that noninvasive vascular tests can reliably exclude major occult arterial damage in injured extremities. Screening for such injuries with Doppler arterial pressure measurements, reserving arteriography for limbs in which the API is less than 0.90, is safe, accurate, and cost effective.

Adolescent↗

Comparison of enteric identification systems.

An evaluation of methods for identification of Enterobacteriaceae was made employing the new commercial Micro-Media Enteric System (MMES) with that of the Analytab Products Incorporated (API) and the Conventional tube media schema as suggested by the Center for Disease Control (CDS). The MMES system employed 20 biochemical tests, the API 21, and the CDC procedure 25. Sixteen of these were identical biochemical tests. Two hundred clinical isolates of Enterobacteriaceae were tested employing procedures recommended by the manufacturers of MMES and API, and methods suggested by CDC. Among the sixteen identical biochemical tests the agreement was 98.0% (Conventional), 98.2% (API), and 97.98% (MMES). Bacteria misidentified by the API system totaled 5 (2.5%), 12 (6%) for the Conventional, and 13 (6.5%) for the MMES. Five of the bacteria misidentified with the MMES procedure were due to false positive citrate tests. This problem was subsequently eliminated. The results of this study indicated that the new MMES method for identification of Enterobacteriaceae compared favorably with both the API and Conventional procedures. However, significant advantages of the MMES method were evident in initial purchase price, utilization of technology time, and less tedium performing the test.

Bacteriological Techniques↗

Isolation and structure of the second of two major peptide products from the precursor to an anglerfish peptide homologous to neuropeptide Y.

The peptide hormone recently isolated from anglerfish endocrine pancreas (aPY) (Andrews, P. C., Hawke, D., Shively, J.E., and Dixon, J.E. (1985) Endocrinology 116, 2677-2681), is a member of a family of peptide hormones which includes pancreatic polypeptide, neuropeptide Y, and the gut peptide YY. A 30-residue carboxyl-terminal fragment of the precursor to aPY has been purified from anglerfish endocrine pancreas in two steps using both classical chromatographic methods and reversed-phase high pressure liquid chromatography. It was identified by sequence homology with the analogous peptide from human preproneuropeptide Y. The sequence was found by Edman degradation and fast atom bombardment mass spectrometry to be SSPEEAVAWLLFKADPSQDIEPRLDDDNAW. The high yield of this fragment (6.5 nmol . g-1) is similar to that previously reported for aPY (7.9 nmol . g-1) and suggests that it is a major product of pro-aPY processing. The data indicate that pro-aPY is proteolytically processed into two major products: the 37-residue aPY and the 30-residue carboxyl-terminal fragment.

Amino Acid Sequence↗

Evidence for the presence of different alpha-1-proteinase inhibitor genes products in mouse plasma.

The plasma alpha-1-proteinase inhibitor (API) of three mouse species Mus domesticus, M. caroli and M. pahori was isolated. Each of the species isoforms were then separated by chromatofocusing; however, no significant differences in association rate constants toward human neutrophil elastase and bovine chymotrypsin were observed. The amino-acid sequence of the P'1-P'15 C-terminal fragments of the API variants indicate that mouse plasma contains at least two different active API isoforms in the case of M. domesticus (five API genes) but only one active API isoform in M. pahori and M. caroli (one API gene).

Amino Acid Sequence↗

Isotype distribution and clinical significance of antibodies to cardiolipin, phosphatidic acid, phosphatidylinositol and phosphatidylserine in systemic lupus erythematosus: prospective analysis of a series of 92 patients.

OBJECTIVE: To determine the prevalence and correlation with clinical manifestations of the IgG and IgM isotypes of antibodies to cardiolipin (aCL), phosphatidic acid (aPA), phosphatidylinositol (aPI) and phosphatidylserine (aPS) in patients with systemic lupus erythematosus (SLE). METHODS: Clinical and laboratory features of 92 consecutive unselected patients with SLE were prospectively studied over two years. aCL, aPA, aPI and aPS were determined by ELISA. RESULTS: aCL were detected in 34 (37%) patients, aPA in 26 (28%), aPI in 22 (24%), and aPS in 29 (32%). A significant association was found between the appearance of thrombosis and the presence of IgG aCL (p < 0.001) and IgG aPS (p < 0.05). A significant association was also found between thrombocytopenia and the presence of IgG aCL (p < 0.001), IgG aPA (p < 0.01), IgG aPI (p < 0.05), and IgG aPS (p < 0.001). The development of hemolytic anemia was associated with the detection of IgM aCL (p < 0.001), IgM aPA (p < 0.05), IgM aPI (p < 0.001), and IgM aPS (p < 0.01). CONCLUSION: We found a relatively high prevalence of aCL, aPA, aPI and aPS in our SLE population and confirmed the presence of a correlation between the IgG isotype of these antibodies and thrombosis and thrombocytopenia, and also between the IgM isotype and hemolytic anemia. These results demonstrate the variety of antiphospholipid antibodies that can be detected in SLE patients, as well as their association with the clinical manifestations of the antiphospholipid syndrome.

Adolescent↗

Honeybee blue- and ultraviolet-sensitive opsins: cloning, heterologous expression in Drosophila, and physiological characterization.

The honeybee (Apis mellifera) visual system contains three classes of retinal photoreceptor cells that are maximally sensitive to light at 440 nm (blue), 350 nm (ultraviolet), and 540 nm (green). We performed a PCR-based screen to identify the genes encoding the Apis blue- and ultraviolet (UV)-sensitive opsins. We obtained cDNAs that encode proteins having a high degree of sequence and structural similarity to other invertebrate and vertebrate visual pigments. The Apis blue opsin cDNA encodes a protein of 377 amino acids that is most closely related to other invertebrate visual pigments that are thought to be blue-sensitive. The UV opsin cDNA encodes a protein of 371 amino acids that is most closely related to the UV-sensitive Drosophila Rh3 and Rh4 opsins. To test whether these novel Apis opsin genes encode functional visual pigments and to determine their spectral properties, we expressed them in the R1-6 photoreceptor cells of blind ninaE mutant Drosophila, which lack the major opsin of the fly compound eye. We found that the expression of either the Apis blue- or UV-sensitive opsin in transgenic flies rescued the visual defect of ninaE mutants, indicating that both genes encode functional visual pigments. Spectral sensitivity measurements of these flies demonstrated that the blue and UV visual pigments are maximally sensitive to light at 439 and 353 nm, respectively. These maxima are in excellent agreement with those determined previously by single-cell recordings from Apis photoreceptor cells and provide definitive evidence that the genes described here encode visual pigments having blue and UV sensitivity.

Animals↗

HIV prevention among Asian and Pacific Islander American men who have sex with men: a critical review of theoretical models and directions for future research.

Nationally, the incidence of AIDS is increasing at a higher rate among Asian and Pacific Islander American men who have sex with men (API MSM) than among white MSM. Furthermore, current HIV prevention efforts are inadequate to slow the rapidly rising HIV epidemic in the gay API community, and little attention has been paid to the applicability of existing behavior change models to APIMSM. This paper reviews the five major models of health behavior change used in HIV prevention for the MSM population: the health belief model, theory of reasoned action, social learning theory, diffusion theory, and the AIDS risk reduction model. Although some of these models have been useful in designing risk reduction programs for API MSM, recent empirical data suggest that the models do not adequately address environmental influences affecting API MSM and limit our choices in prevention strategies to the level of the individual. We propose an ecological model for health promotion as a potentially useful theoretical framework, and suggest prevention strategies directed at the individual, the family, the general API community, and the mainstream gay community to reduce HIV risk among API MSM.

Asian↗

Malariometry in district Ratnagiri during 1988-1993.

Ratnagiri, a coastal district situated in the western part of Maharashtra, is stratified as 'Non-Problem District' as far as Malaria is concerned based on API, topography, rainfall, vector species, Vulnerability etc. Konkan rail project was launched in 1991 and 6 out of 9 blocks of districts Ratnagiri are penetrated by the rail-line. The local ecology of the district is disturbed on account of the project, which is expected to favor malarial transmission. A study based on secondary data was undertaken with following objectives: To assess various operational indicators under NMEP during 1988-93 in the district with respect to their quantitative and qualitative fulfillment. To assess API in the district during same period in the context of inception of Konkan rail. It disclosed that the operational indicators like SPR, SFR & Pf Percentage showed upward trend since 1991 i.e. the year of inception of the Konkan rail project. With ABER consistently above 10% & concordance of the cross-checking results above 96%, the estimate of API becomes more meaningful. Though API shows upward trend, it was never above 2 during 1988-93. Less number of positive cases were found in Active Surveillance during 1988 to 1993. The contribution of Drug Distribution Centres (DDCs) is almost negligible in the district. In-depth analysis of positive cases revealed that the immigrants suffered more & May to July was the season for malaria transmission in the district during the said period. More people above 15 yrs. and more males were found malaria positive which may be because of more outdoor life of this group. Block wise analysis revealed that Mandanged & Khed Blocks showed API more than 2 since 1992. Paradoxically, Mandangad is a coastal block without rail-line, while Khed block is situated away from seashore but has rail-line. More irrigation, less adequate surveillance because of staff vacancy & nonfunctional Drug Distribution Centres (DDCs), more losses to radical treatment are the probable factors responsible for higher API in Mandangad and Khed blocks as compared with the rest of the blocks from the District Ratnagiri.

Adolescent↗

Racial and ethnic disparities in faculty promotion in academic medicine.

CONTEXT: Previous studies have suggested that minority medical school faculty are at a disadvantage in promotion opportunities compared with white faculty. OBJECTIVE: To compare promotion rates of minority and white medical school faculty in the United States. DESIGN AND SETTING: Analysis of data from the Association of American Medical Colleges' Faculty Roster System, the official data system for tracking US medical school faculty. PARTICIPANTS: A total of 50,145 full-time US medical school faculty who became assistant professors or associate professors between 1980 and 1989. Faculty of historically black and Puerto Rican medical schools were excluded. MAIN OUTCOME MEASURES: Attainment of associate or full professorship among assistant professors and full professorship among associate professors by 1997, among white, Asian or Pacific Islander (API), underrepresented minority (URM; including black, Mexican American, Puerto Rican, Native American, and Native Alaskan), and other Hispanic faculty. RESULTS: By 1997, 46% of white assistant professors (13,479/28,953) had been promoted, whereas 37% of API (1123/2997; P<.001), 30% of URM (311/1053, P<.001), and 43% of other Hispanic assistant professors (256/598; P =.07) had been promoted. Similarly, by 1997, 50% of white associate professors (7234/14,559) had been promoted, whereas 44% of API (629/1419; P<.001), 36% of URM (101/280; P<.001), and 43% of other Hispanic (122/286; P =.02) associate professors had been promoted. Racial/ethnic disparities in promotion were evident among tenure and nontenure faculty and among faculty who received and did not receive National Institutes of Health research awards. After adjusting for cohort, sex, tenure status, degree, department, medical school type, and receipt of NIH awards, URM faculty remained less likely to be promoted compared with white faculty (relative risk [RR], 0.68 [99% confidence interval CI, 0.59-0.77] for assistant professors and 0.81 [99% CI, 0.65-0.99] for associate professors). API assistant professors also were less likely to be promoted (RR, 0.91 [99% CI, 0.84-0.98]), whereas API associate professors and other Hispanic assistant and associate professors were promoted at comparable rates. CONCLUSION: Our data indicate that minority faculty are promoted at lower rates compared with white faculty. JAMA. 2000;284:1085-1092

Career Mobility↗

Enantiomeric separation and detection by high-performance liquid chromatography-mass spectrometry of 2-arylpropionic acids derivatized with benzofurazan fluorescent reagents.

The enantiomneric separation and the detection of 2-arylpropionic acids after derivatization with the fluorescent reagents with a benzofurazan structure, (S)-(+)-4-(N,N- dimethylaminosulphonyl)-7-(3-aminopyrrolidin-1-yl)-2,1,3-ben zoxadiazole ((S)-DBD-Apy), (R)-(-)-4-nitro-7-(3-aminopyrrolidin-1-yl)-2,1,3- benzoxadiazole ((R)-NBD-Apy), 4-N,N-dimethylaminosulphonyl-7-piperazino-2,1,3-benzoxadi zole (DBD-PZ) and N-hydrazinoformylmethyl-N-methylamino-4,4- N,N-dimethylaminosulphonyl-2,1,3-benzoxadiazole (DBD-CO-Hz) by high-performance liquid chromatography (HPLC) and electrospray ionization mass spectrometry (ESI-MS) were examined. The diastereomeric derivatization with (S)-DBD-Apy or (R)-NBD-Apy and the separation on the reversed phase column afforded the high sensitivity. The separation on chiral stationary phase after non-chiral derivatization with DBD-PZ or DBD-CO-Hz provided less sensitivity. The signal-to-noise ratio of (S)-DBD-Apy-(S)-ketoprofen of 200:1 was observed for 12.5 picomole (pmol) injection and selected ion monitoring (SIM) of the quasi-molecular ion after splitting 1:7 before entering into the electrospray ion sources. As a result, the usefulness of these reagents for MS detection has been demonstrated.

Benzoxazoles↗

Differences in treatment patterns for localized breast carcinoma among Asian/Pacific islander women.

BACKGROUND: Many studies have examined racial/ethnic differences in treatment for localized breast carcinoma, but to the authors' knowledge few have included Asian/Pacific Islander (API) women. METHODS: The population-based study included API and non-Hispanic white women diagnosed with localized invasive breast carcinoma in the Greater San Francisco Bay Area during 1994 (n = 1772). Multiple logistic regression was used to assess the association between race/ethnicity and type of surgery, radiation therapy following breast-conserving surgery (BCS), and hormone therapy for estrogen receptor-positive tumors while adjusting for demographic, medical, and census block-group socioeconomic characteristics. RESULTS: API women were significantly more likely to undergo mastectomies than white women (58% vs. 42%). This difference remained for Chinese and Filipino women after multivariate adjustment (odds ratio vs. whites [OR] = 2.4, 95% confidence interval [95% CI] = 1.4-4.2; OR [95%CI] = 1.8[1.0-3.1], respectively). Chinese women were also more likely than white women to not receive adjuvant therapy, be it radiation after BCS or hormone therapy for estrogen receptor-positive disease. Other API women did not differ from white women in adjuvant therapy use. CONCLUSIONS: This population-based study identified differences in treatment for localized breast carcinoma by race/ethnicity that were not explained by differences in demographic, medical, or socioeconomic characteristics. These results underscore the importance of looking at treatment patterns separately for API subgroups and support the need for research into cultural differences that may influence breast carcinoma treatment choices.

Adult↗

New method for the analysis of cell cycle-specific apoptosis.

BACKGROUND: In this study, a new method for the analysis of cell cycle specificity of apoptosis was designed by using a modified annexin V and propidium iodide (API) method. METHODS: Cells of the human promyelocytic HL-60 line treated with camptothecin (CPT) or ultraviolet light (UV) were labeled with fluorescein isothiocyanate-conjugated annexin V and prefixed with 1% methanol-free formaldehyde on ice, and their DNA was stained stoichiometrically with propidium iodide in the presence of digitonin. Cellular green and red fluorescences were measured by flow cytometry. RESULTS: Cell cycle specificity of apoptosis obtained by the API method and those analyzed for the presence of DNA strand breaks by using terminal deoxynucleotidyl transferase (TdT) assay were similar: CPT- or UV-induced apoptosis preferentially in S- or G1-phase cells, respectively. When the internucleosomal DNA degradation was prevented by the serine protease inhibitor N-tosyl-L-phenylalanine chloromethyl ketone, apoptotic cells could not be detected by the TdT assay but were identified by the API method. CONCLUSIONS: The API method, similar to the TdT assay, accurately detects the cell cycle phase specificity of apoptosis. Also, the API method appears to detect earlier stages of apoptosis than the TdT assay.

Annexin A5↗

Impact of excipient particle size on measurement of active pharmaceutical ingredient absorbance in mixtures using frequency domain photon migration.

A system of dual-component powder mixtures, varying in excipient particle size and concentration of active pharmaceutical ingredient (API), is analyzed using frequency domain photon migration (FDPM) techniques. The results show that the FDPM-measured absorption coefficient increases linearly with increasing API concentration whereas the isotropic scattering coefficient shows no sensitivity to changes in API concentration. It is further seen that the absorption coefficient of blends, owing to the API, is not only linearly dependent on its concentration, but that this relationship is furthermore related to the excipient particle size. Finally, a comparison between near-infrared absorbance and FDPM-measured isotropic scattering as a function of reciprocal particle size is made to highlight FDPM as a powerful particle sizing tool without need for calibration. Overall, this study presents FDPM as a comprehensive method for detection of API concentration independent of excipient particle size.

Absorption↗