Validity of diagnostic and drug data in standardized nursing home resident assessments: potential for geriatric pharmacoepidemiology. SAGE Study Group. Systematic Assessment of Geriatric drug use via Epidemiology

OBJECTIVES

The Health Care Financing Administration requires that patients admitted to certified nursing homes be assessed with the Minimum Data Set, a data collection instrument containing more than 300 demographic, diagnostic, clinical, and treatment variables. Long-term care databases potentially may be used to assess the outcomes of specific treatments as well as drug effectiveness. The authors sought to ascertain reliability and validity of diagnostic and drug data in a database obtained by merging the Minimum Data Set with detailed information on drugs consumed by each resident.

METHODS

A population of 296,379 residents of 1,492 nursing homes in Kansas, Maine, Mississippi, New York, and South Dakota participated in the study between 1992 and 1994. Minimum Data Set clinical diagnoses were contrasted with selected resident characteristics and a variety of symptoms and treatments. Limited to individuals who had been hospitalized in the 6 months preceding the first assessment, Minimum Data Set diagnoses were compared with those on the hospital discharge claims maintained in the Medicare Provider Analysis and Review database. Finally, the probability that the use of selected drugs predicted the correspondent gender-specific, age-specific, or unique labeled indication was estimated.

RESULTS

The positive predictive value for Minimum Data Set diagnoses compared with gender or function measures exceeded 0.9, and it was 0.8 for specific symptoms and 0.6 for virtually all other comparisons. The positive predictive value for Minimum Data Set diagnoses compared with those from hospital claims was approximately 0.7 for all chronic medical conditions, except for depression and asthma/chronic obstructive pulmonary disease/emphysema. The positive predictive value for acute/subacute diagnoses (ie, pneumonia, urinary tract infection, anemia) that may resolve during hospital stay was less than 0.5. The positive predictive value for selected drugs, except estrogens, compared with age and gender was close to 1.0 in all cases. When compared to their labeled indication, the positive predictive value was more than 0.6 for all drugs considered, with 0.97, 0.91, and 0.87 for tacrine and Alzheimer's disease, antidiabetics and diabetes mellitus, and L-dopa and Parkinson's disease, respectively.

CONCLUSIONS

These findings point to the overall validity of the drug and clinical data in this Minimum Data Set-based data set. Additional validation efforts will determine whether this data set can be used for studies of geriatric pharmacoepidemiology and for analyses of the influence of different policies and practices on residents' outcomes.

Molecular analysis of cellulose biosynthesis in Arabidopsis

Cellulose, an abundant, crystalline polysaccharide, is central to plant morphogenesis and to many industries. Chemical and ultrastructural analyses together with map-based cloning indicate that the RSW1 locus of Arabidopsis encodes the catalytic subunit of cellulose synthase. The cloned gene complements the rsw1 mutant whose temperature-sensitive allele is changed in one amino acid. The mutant allele causes a specific reduction in cellulose synthesis, accumulation of noncrystalline beta-1,4-glucan, disassembly of cellulose synthase, and widespread morphological abnormalities. Microfibril crystallization may require proper assembly of the RSW1 gene product into synthase complexes whereas glucan biosynthesis per se does not.

Immunohistochemical analysis of growth factor expression and localization in gastric coronary vein of cirrhotic patients

This study was designed to investigate the expression and localization of PDGF, bFGF, EGF, and TGF alpha in gastric coronary vein of cirrhotic (n = 30) and non-cirrhotic patients (n = 10) using immunohistochemical technique. The strongly positive immunostaining rate were 93%, 89%, 70% and 68% respectively in cirrhotic patients. The immunostaining was negative in non-cirrhotic patients. The damage to endothelium, hypertrophy and hyperplasia of vascular smooth muscle cells and vascular remodeling were seen in gastric coronary vein of cirrhotic patients. These results suggested that gastric coronary vein could produce growth factor during cirrhosis, the growth factor can act on the vascular function and/or structure via autocrine-paracrine mechanism.

A novel method for quantitative analysis of apoptosis

In the present study, we describe a method of quantifying DNA fragmentation. This assay is based on saturation labeling 3'-ends of DNA fragments with alpha(32)PdCTP in the presence of 2',3'-dideoxy-cytidine-5'-triphosphate (ddCTP) by terminal deoxynucleotidyl transferase (TdT). The saturation labeling of 3'-ends of DNA fragments was performed by adding different concentrations of alpha(32)PdCTP to a DNA sample, from which a maximal labeling (Lmax) and a kinetic parameter (Km) of the TdT reaction are calculated. The saturated labeling gives true quantitation that makes it possible to accurately compare quantities of DNA fragments among different samples. This method requires as little as 5 ng of DNA and increases the sensitivity of apoptotic DNA detection by at least 200-fold relative to the widely used ethidium staining method. The application of this method in an apoptosis study showed that (a) a time- and dose-dependent increase in the number of DNA strand breaks in apoptotic lymphocytes was induced by dexamethasone, and (b) age-dependent apoptosis occurred in the cardiac tissues of spontaneously hypertensive rats. Results of this assay were confirmed by the DNA ladder pattern exhibited after electrophoresis as well as the morphologic changes of apoptosis observed under electron microscopy and were very consistent with results obtained in quantifying apoptotic cells by flow cytometric analysis (r = 0.98, p = 0.002). Thus, this assay is quantitative, simple, sensitive, and useful for assessing apoptosis.

[Determination of amino acid contents in cotton-seed-cake powder]

In this work, the contents of amino acids in three kinds of cotton-seed-cake powder from domestic and abroad were determined by using Waters Automatic Amino Acid Analyzer with post-column derivatization and fluorescence detection. The operating conditions were cation exchange resin column, 250 mm x 4.6 mm i.d., gradient elution, detection wavelength lambda(ex) = 338 nm and lambda(em) = 425 nm. The results showed that contents of amino acids from both domestic cotton seed cakes were less than those from abroad.

Monocyte chemoattractant protein inhibits the generation of tumor-reactive T cells

The adoptive transfer of tumor-sensitized T cells can eradicate disseminated malignancy in murine animal models. T cells must be sensitized to tumor antigens in vivo to acquire antitumor reactivity. T-cell sensitization has been demonstrated to be dependent on host antigen-presenting cells. Tumor-associated macrophages are a heterogeneous population of cells that may have both inhibitory and stimulatory influences on the sensitization of naive T cells. Here we demonstrate that a weakly immunogenic tumor, the MCA 205 sarcoma, produces substantial amounts of murine monocyte chemoattractant protein 1 (MCP-1). Neutralization of MCP-1 during in vivo T-cell sensitization resulted in T cells that possessed enhanced therapeutic activity against established pulmonary metastases. These T cells sensitized during MCP-1 depletion also exhibited enhanced production of IFN-gamma upon recognition of tumor targets. These results demonstrate that MCP-1 can have a potent inhibitory influence on the development of tumor-reactive T cells.

An estrogen receptor binding site within the human galanin gene

Regulation of galanin gene expression in the anterior pituitary (AP) is positively influenced by estrogen in rodents and undetermined in humans. The objective of this study was to investigate the mechanism behind estrogen induction of galanin by identifying any putative estrogen receptor (ER) binding sequences within the human galanin promoter that may function as estrogen response elements (ERE). Two regions, gERE1 and gERE2, were identified in the galanin 5'-flanking sequence with similarity to the full 13-base ERE consensus previously defined in the vitellogenin gene (vERE). Both sequences were tested in mobility shift assays for the ability to bind nuclear proteins isolated from rat AP tissue or MtTW-10 pituitary tumors. Only the distal sequence at -527 (gERE1) yielded an ERE-specific DNA/protein complex distinguished by mobility and cross-competition with vERE. The gel mobility pattern of the DNA/protein complex was comparable between the pituitary tissue and tumor extracts. However, DNA/protein affinity estimations demonstrated a greater affinity of pituitary proteins for gERE1 over the vERE sequence. Evidence that the human ER (hER) does recognize the gERE1 sequence in the human galanin gene was provided by electrophoretic mobility shift assays (EMSAs) with Sf9 extracts enriched in recombinant hER. In addition, antibodies specific for the hER recognized the gERE1/protein complex in supershift experiments. Enhancer activity by gERE1 was detected in transient transfections of the rat GH3 pituitary cell line, resulting in a 4-fold induction of expression driven by the heterologous thymidine kinase promoter in the presence of estrogen. Evidence for ER regulation of the gERE1 enhancer was demonstrated by: 1) inhibition of enhancement using the specific ER antagonist ICI 164,384; and 2) enhancement in HeLa cells that was dependent upon coexpression with hER. Enhancement by gERE1 was half the magnitude as that from the vERE element and may reflect a difference in affinity or composition of the ER complex between the two sequences. These data demonstrate the presence of a functional ERE sequence within the human galanin gene that could potentially function as a regulatory element for estrogen action in the AP.

Increased recruitment of hematopoietic progenitor cells underlies the ex vivo expansion potential of FLT3 ligand

The ligand for flt-3 (FLT3L) exhibits striking structural homology with stem cell factor (SCF) and monocyte colony-stimulating factor (M-CSF) and also acts in synergy with a range of other hematopoietic growth factors (HGF). In this study, we show that FLT3L responsive hematopoietic progenitor cells (HPC) are CD34+CD38-, rhodamine 123dull, and hydroperoxycyclophosphamide (4-HC) resistant. To investigate the basis for the capacity of FLT3L to augment the de novo generation of myeloid progenitors from CD34+CD38- cells, single bone marrow CD34+CD38- cells were sorted into Terasaki wells containing serum-free medium supplemented with interleukin-3 (IL-3), IL-6, granulocyte colony-stimulating factor (G-CSF), SCF (4 HGF) +/- FLT3L. Under these conditions, FLT3L recruited approximately twofold more CD34+CD38- cells into division than 4 HGF alone. The enhanced proliferative response to FLT3L was evident by day 3 and was maintained at all subsequent time points examined. In accord with these findings, we also show that transduction of CD34+CD38- cells with the LAPSN retrovirus is enhanced by FLT3L. The results of these experiments therefore indicate that increased recruitment of primitive HPC into cell cycle underlies the ex vivo expansion potential of FLT3L and also its ability to improve retroviral transduction of HPC.

Adeno-associated virus type 2-mediated transfer of ecotropic retrovirus receptor cDNA allows ecotropic retroviral transduction of established and primary human cells

The cellular receptors that mediate binding and internalization of retroviruses have recently been identified. The concentration and accessibility of these receptors are critical determinants in accomplishing successful gene transfer with retrovirus-based vectors. Murine retroviruses containing ecotropic glycoproteins do not infect human cells since human cells do not express the receptor that binds the ecotropic glycoproteins. To enable human cells to become permissive for ecotropic retrovirus-mediated gene transfer, we have developed a recombinant adeno-associated virus type 2 (AAV) vector containing ecotropic retroviral receptor (ecoR) cDNA under the control of the Rous sarcoma virus (RSV) long terminal repeat (LTR) promoter (vRSVp-ecoR). Established human cell lines, such as HeLa and KB, known to be nonpermissive for murine ecotropic retroviruses, became permissive for infection by a retroviral vector containing a bacterial gene for resistance to neomycin (RV-Neo(r)), with a transduction efficiency of up to 47%, following transduction with vRSVp-ecoR, as determined by the development of colonies that were resistant to the drug G418, a neomycin analog. No G418-resistant colonies were present in cultures infected with either vRSVp-ecoR or RV-Neo(r) alone. Southern and Northern blot analyses revealed stable integration and long-term expression, respectively, of the transduced murine ecoR gene in clonal isolates of HeLa and KB cells. Similarly, ecotropic retrovirus-mediated Neo(r) transduction of primary human CD34+ hematopoietic progenitor cells from normal bone marrow was also documented, but only following infection with vRSVp-ecoR. The retroviral transduction efficiency was approximately 7% without prestimulation and approximately 14% with prestimulation of CD34+ cells with cytokines, as determined by hematopoietic clonogenic assays. No G418-resistant progenitor cell colonies were present in cultures infected with either vRSVp-ecoR or RV-Neo(r) alone. These results suggest that sequential transduction of primary human cells with two different viral vectors may overcome limitations encountered with a single vector. Thus, the combined use of AAV- and retrovirus-based vectors may have important clinical implications for ex vivo and in vivo human gene therapy.

Prediction of protein supersecondary structures based on the artificial neural network method

The sequence patterns of 11 types of frequently occurring connecting peptides, which lead to a classification of supersecondary motifs, were studied. A database of protein supersecondary motifs was set up. An artificial neural network method, i.e. the back propagation neural network, was applied to the predictions of the supersecondary motifs from protein sequences. The prediction correctness ratios are higher than 70%, and many of them vary from 75 to 82%. These results are useful for the further study of the relationship between the structure and function of proteins. It may also provide some important information about protein design and the prediction of protein tertiary structure.

The activation of human platelets mediated by two monoclonal antibodies raised against CD9

The platelet activation induced by two anti-human platelet P24/CD9 McAbs was investigated. The results showed that: the pathway of platelet aggregation induced by the two McAbs (HI117 and SJ9A4) is not the same; HI117 and SJ9A4 induced the phosphorylation of platelet proteins (40KD and 20KD) when platelets were activated; but HI117 didn't cause a rise in intracellular Ca2+ concentration in activated platelets compared with SJ9A4; the epitope recognized by HI117 and SJ9A4 is different and this is probably the real reason why the two CD9 McAbs play different roles in platelet activation. Additionally McAbs HI117 and SJ9A4 could not promote associates of other proteins (e.g.: GPIIb/IIIa) with P24/CD9 on activated human platelets. All these results indicate that the mechanism of platelet activation induced by HI117 or SJ9A4 is different form each other. It suggests that CD9 antigen play an important and complex role in platelet activation.

Angiotensin-converting enzyme gene and atherosclerosis

Common variants of the angiotensin-converting enzyme (ACE) gene (ACE ie humans, Ace in mice) associated with changes in circulating ACE activities have been suggested to confer differential risks for atherosclerosis. Using a mouse model of atherosclerosis induced by heterozygosity for apolipoprotein E gene disruption and an atherogenic diet, we have studied the impact on atherogenesis of a mutation that changes the level of function of Ace. We find that this genetically determined change does not influence the size or complexity of atherosclerotic lesions. Ace genotype was not a significant determinant of lesion size in female (+/+ = 12.9 +/- 1.5 and +/- = 11.7 +/- 1.6 microns2 x 10(4)) or male (+/+ = 0.95 +/- 0.25 and +/- = 1.83 +/- 0.59 microns2 x 10(4)) mice; however, lesions were significantly larger (P < .001) in female than male mice. Ace genotype also did not affect lesion complexity; however, lesions in females showed significantly increased frequency of cholesterol clefts, acellular cores, fibrous caps, and calcifications compared with those in males. The hypothesis that genetic variation in the level of ACE gene expression affects the development of atherosclerosis is not supported by these findings.

[Packing drainage of transmastoid approach for treatment of otogenic brain abscess: a report of 30 cases]

Thirty cases of patients with otogenic brain abscess (OBA) who received mastoid radical operations were treated simultaneously by means of packing drainage via the appoach of the mastoid operative cavity. 26 cases of those were cured. The results showed that the therapeutical method gave satisfactory effectiveness and had many advantages. It provided an effective montitor for retraction and had many vomica, and gave ample drainage for retraction in that it made OBA seldom recur. The operative procedure is fit for the great majority of OBA. The paper also discussed intraoperative and postoperative complications and other problems pertinent to the operation.

Treatment of subcutaneous tumor with adoptively transferred T cells

Adoptive immunotherapy with T cells directed at tumor antigens has been demonstrated to result in the regression of malignant tumors in humans. These encouraging results have prompted the further exploration of parameters necessary to treat tumor in various locations in animal models. We have demonstrated that T cells that are sensitized to tumor antigens and then ex vivo cultured are capable of eradicating pulmonary metastases. In this report, we demonstrate that these T cells are capable of eliminating subcutaneous tumor deposits. Critical to the successful treatment of subcutaneous tumor was treatment with a large number of adoptively transferred T cells and pretreatment of the mice with irradiation. The transfer of T cells from tumor-bearing mice into irradiated mice failed to inhibit the therapeutic effect of ex vivo cultured T cells, suggesting that irradiation was not acting only as an immunosuppressant. Irradiation resulted in increased expression of the F4/80 and 33D1 epitopes on antigen-presenting cells within the tumor. The therapeutic effect of the adoptively transferred T cells was eliminated if either CD4 cells or CD8 cells were depleted. Naive T cells subjected to the same culture conditions were completely ineffective at eliminating tumor. These results demonstrate that adoptively transferred T cells derived from tumor-bearing hosts can treat subcutaneous tumor deposits, and they define the conditions necessary for the elimination of tumor in this location.

Isoforms of Na,K-ATPase alpha and beta subunits in the rat cerebellum and in granule cell cultures

There are multiple isoforms of the Na,K-ATPase in the nervous system, three isoforms of the alpha subunit, and at least two of the beta subunit. The alpha subunit is the catalytic subunit. The beta subunit has several roles. It is required for enzyme assembly, it has been implicated in neuron-glia adhesion, and the experimental exchange of beta subunit isoforms modifies enzyme kinetics, implying that it affects functional properties. Here we describe the specificities of antibodies against the Na,K-ATPase beta subunit isoforms beta1 and beta2. These antibodies, along with antibodies against the alpha subunit isoforms, were used to stain sections of the rat cerebellum and cultures of cerebellar granule cells to ascertain expression and subcellular distribution in identifiable cells. Comparison of alpha and beta isoform distribution with double-label staining demonstrated that there was no preferential association of particular alpha subunits with particular beta subunits, nor was there an association with excitatory or inhibitory neurotransmission modes. Isoform composition differences were seen when Purkinje, basket, and granule cells were compared. Whether beta1 and beta2 are specific for neurons and glia, respectively, has been controversial, but expression of both beta subunit types was seen here in granule cells. In rat cerebellar astrocytes, in sections and in culture, alpha2 expression was prominent, yet the expression of either beta subunit was low in comparison. The complexity of Na,K-ATPase isoform distribution underscores the subtlety of its regulation and physiological role in excitable cells.

[A research on real-time ventricular QRS classification methods for single-chip-microcomputers]

Ventricular QRS classification is key technique of ventricular arrhythmias detection in single-chip-microcomputer based dynamic electrocardiogram real-time analyser. This paper adopts morphological feature vector including QRS amplitude, interval information to reveal QRS morphology. After studying the distribution of QRS morphology feature vector of MIT/BIH DB ventricular arrhythmia files, we use morphological feature vector cluster to classify multi-morphology QRS. Based on the method, morphological feature parameters changing method which is suitable to catch occasional ventricular arrhythmias is presented. Clinical experiments verify missed ventricular arrhythmia is less than 1% by this method.

Construction of recombinant adeno-associated virus vector containing the rat preproinsulin II gene

We have investigated a possible delivery system for the rat preproinsulin II gene (rI2) utilising a recombinant adeno-associated virus (rAAV) vector system, with the long-term goal of engineering stably infected insulin-producing cell lines. The rAAV vector was chosen because it is a safe and nonpathogenic method for gene transfer. The plasmid pBC12BI (ATCC) was purified and digested with restriction enzymes SepI and StuI to release a fragment containing the Rous sarcoma virus long terminal repeat (RSV-LTR) promoter-driven rat preproinsulin II gene (rI2). Subsequently, the RSV-rI2 gene fragment was cloned into the BamHI site of rAAV vector plasmid pWP-19 to produce the rI2 recombinant plasmid designated pLP-1. The pWP-19 also encodes the AAV inverted terminal repeats for integration and replication and the herpes virus thymidine kinase promoter-driven gene for neomycin resistance (neoR). The cell line 293 (ATCC) was then cotransfected with pLP-1 and helper plasmid pAAV/AD, which is required for viral replication. The rAAV genome, now containing rI2, was rescued using adenovirus and packaged into mature AAV virions termed vLP-1. Finally, human pancreatic adenocarcinoma cells (HPAC; ATCC) were exposed to vLP-1, selected for G418 resistance, and screened for insulin production. Successful rescue was confirmed by Southern blot analysis using the rI2 gene probe derived from the original plasmid. The final titer of 1.25 x 10(9) particles/ ml was determined by DNA slot blots using pLP-1 as the standard, HPAC cells were infected with vLP-1 (termed HPAC/rI2). Integration of the rI2 genome in G418-resistant clones was confirmed by Southern blot analysis and again after 6 months in culture by amplification of the rI2 gene by PCR. Insulin gene transcription was confirmed by RT-PCR. We have developed a rAAV-mediated gene transfer system for the rat preproinsulin II gene. Successful transduction and stable integration of rI2 into HPAC was achieved. Production of insulin by HPAC/rI2 was confirmed by RIA and RT-PCR, validating this system as an effective approach to experimental gene therapy.

[Preparation and characterization of recombinant retroviral vector containing t-PA cDNA]

A recombinant retroviral vector containing tissue-type plasminogen activator (t-PA) cDNA was constructed and transfected into PA317 viral packaging cells, forming intact virus particles. Under electron microscope the recombinant retroviral particles were composed of envelope, capsid and core. These viral particles were spherical with a diameter of 90-180nm, and spread dispersely in the cells. NIH3T3 cell infected by retrovirus particles were screened with G418. The virus titer of 6 x 10(8) CFU/L was verified by counting the positive clones two weeks after screening. The expression of t-PA was demonstrated in the NIH3T3 cells infected with the recombinant virus.

Biochemical and mutational analysis of a gingipain-like peptidase activity from Prevotella ruminicola B(1)4 and its role in ammonia production by ruminal bacteria

A chemical mutagenesis protocol was used with the ruminal bacterium Prevotella ruminicola strain B(1)4 to generate mutant strains defective in peptidase activity. Compared with the wild-type parent strain, the isolated mutants possessed 1/10 of the enzyme activity responsible for cleavage of glycine-arginine-4-methoxy-beta-naphthylamide (Gly-Arg-MNA). A concomitant loss in activity against arginine-arginine-4-methoxy-beta-naphthylamide (Arg-Arg-MNA) was also observed. Both activities were similarly affected by various proteinase inhibitors, suggesting that the same enzyme is responsible for the Arg-Arg-MNA peptidase and Gly-Arg-MNA peptidase activities. Growth rates of wild-type and mutant strains grown in batch culture with various nitrogen sources did not differ. However, a role for the Gly-Arg-MNA peptidase activity was demonstrated in coculture experiments with gram-positive, ammonia-producing ruminal bacteria. The rate and extent of ammonia production were reduced by approximately 25% in cocultures containing the mutants when compared with that of wild-type-containing cultures. These reductions could not be accounted for simply by the decrease in ammonia production by the mutant strain alone. To our knowledge, this paper reports the first successful use of chemical mutagenesis with ruminal microorganisms.

Intraocular pressure in inbred mouse strains

PURPOSE

To develop a protocol to measure the intraocular pressure (IOP) of living mice and to determine the IOP of genetically different mouse strains.

METHODS

Eyes of anesthetized animals were cannulated with a very fine fluid-filled glass microneedle. The microneedle was connected to a pressure transducer, and the pressure signal was analyzed with a computer system. Intraocular pressures of male C3H/He iota, C57BL/ 6 iota, A/iota, and BALB/c iota mice were determined.

RESULTS

Differences in IOP were detected between genetically distinct mouse strains maintained in virtually identical environments. C3H/He iota was the strain with the highest average IOP (13.7 +/- 0.8 mm Hg). This strain average was 1.4 mm Hg higher than that for C57BL/6 iota (12.3 +/- 0.5 mm Hg; P = 0.14), 4.3 mm Hg higher than that for A/iota (9.4 +/- 0.5 mm Hg; P < 0.001), and 6 mm Hg higher than that for BALB/c iota (7.7 +/- 0.5 mm Hg; P < 0.001).

CONCLUSIONS

The authors have developed an accurate and reliable procedure for measuring intraocular pressure in living mice. This procedure can detect IOP differences between groups of mice that differ by genotype.

[Intracerebral transplantation of genetically modified cells for Parkinson's disease]

The clinical application of brain transplantation for treating Parkinson's disease (PD) is limited because it is difficult to obtain ideal donor cells. In this study, the tyrosine hydroxylase (TH) gene was introduced into NIH-3T3 cell line and the genetically modified cells reacted positively with TH antiserum and released L-dopa. These cells were implanted into the striatum of PD rats. 3,6,9,12 days after implantation, the average rate of the abnormal rotational behavior recovery was 52.6%, 68.4%, 63.2%, 44.7%, respectively. This result is considered to be potential for further clinical application.

Angiotensin-converting enzyme gene mutations, blood pressures, and cardiovascular homeostasis

A common polymorphism of the angiotensin-converting enzyme (ACE) gene (ACE in humans, Ace in mice) is associated with differences in circulating ACE levels that may confer a differential risk for cardiovascular diseases. To study the effects of genetically determined changes in Ace gene function within a defined genetic and environmental background, we have studied mice having one, two, or three functional copies of the Ace gene at its normal chromosomal location. ACE activities in the serum increased progressively from 62% of normal in the one-copy animals to 144% of normal in the three-copy animals (P < 10(-15), n = 132). The blood pressures of the mice having from one to three copies of the Ace gene did not differ significantly, but the heart rates, heart weights, and renal tubulointerstitial volumes decreased significantly with increasing Ace gene copy number. The level of kidney renin mRNA in the one-copy mice was increased to 129 +/- 9% relative to that of the normal two-copy mice (100 +/- 4%, P = .01, n = 16). We conclude that significant homeostatic adaptations successfully normalize the blood pressures of mice that have quantitative changes in Ace gene function. Our results suggest only that quantitative changes in expression of the Ace gene will observably affect blood pressures when accompanied by additional environmental or genetic factors that together with Ace exceed the capacity of the homeostatic mechanisms.

Development and validation of an LC-MS-MS method for the determination of terfenadine in human plasma

A sensitive LC-MS-MS method capable of quantifying terfenadine at levels down to 100 pg ml-1 in human plasma is reported. The method was validated over a linear range from 0.1 to 5.0 ng ml-1 using a liquid-liquid extraction with a deuterium-labelled internal standard. The between-run precision and accuracy of the calibration standards were 2.6-6.0% RSD and -2.0 to +2.2% relative error (RE). The between-run and within-run precision and accuracy of quality control samples (0.3, 1.5 and 3.5 ng ml-1) were 1.0-5.9% RSD and +1.7 to +6.3% RE. This method was applied to the analysis of human plasma samples.

Biochemical evaluation of photolabile precursors of choline and of carbamylcholine for potential time-resolved crystallographic studies on cholinesterases

Acetylcholinesterase and butyrylcholinesterase both rapidly hydrolyze the neurotransmitter acetylcholine. The unusual three-dimensional structure of acetylcholinesterase, in which the active site is located at the bottom of a deep and narrow gorge, raises cogent questions concerning traffic of the substrate, acetylcholine, and the products, choline and acetate, to and from the active site. Time-resolved crystallography offers a promising experimental approach to investigate this issue but requires a suitable triggering mechanism to ensure efficient and synchronized initiation of the dynamic process being monitored. Here we characterize the properties of two photolabile triggers which may serve as tools in time-resolved crystallographic studies of the cholinesterases. These compounds are 2-nitrobenzyl derivatives of choline and of carbamylcholine, which generate choline and carbamylcholine, respectively, upon photochemical fragmentation. Both photolabile compounds are reversible inhibitors, which bind at the active sites of acetylcholinesterase and butyrylcholinesterase with inhibition constants in the micromolar range, and both photofragmentation processes occur rapidly and with a high quantum yield, without substantial photochemical damage to the enzymes. Photolysis both of acetylcholinesterase and of butyrylcholinesterase, complexed with a 2-nitrobenzyl derivative of choline, resulted in regeneration of enzymic activity. Photolysis of acetylcholinesterase complexed with the 2-nitrobenzyl derivative of carbamylcholine led to time-dependent inactivation, resulting from carbamylation of acetylcholinesterase, which could be reversed upon dilution, due to decarbamylation. Both sets of experiments demonstrated release of choline within the active site. In the former case, choline was produced photochemically at the active site. In the latter case, choline was generated enzymatically, within the active site, concomitantly with carbamylation of the acetylcholinesterase. The two photolabile compounds may thus serve as complementary probes for time-resolved studies of the route of product release from the active sites of the cholinesterases.

Blood pressure and fluid-electrolyte balance in mice with reduced or absent ANP

Atrial natriuretic peptide (ANP)-gene knockout mice of three genotypes (+/+, +/-, and -/-) were maintained on a low-salt diet (0.008% NaCl). They were then fed either the same low-salt diet or a high-salt diet (8% NaCl) for 1 wk. No differences were found among genotypes in daily food and water intakes or in urinary volume and electrolyte excretions. Arterial blood pressures measured in anesthetized animals at the end of the dietary regimen were significantly and similarly increased in -/- compared with +/+ mice on each diet. Renal excretion of fluid and electrolytes was measured in anesthetized mice before and after acute blood volume expansion. No genotype differences were observed before volume expansion. After volume expansion the wild-type (+/+) mice had much greater saluretic responses than either the heterozygous (+/-) or the homozygous mutant (-/-) animals on the low-salt diet but not on the high-salt diet. We conclude that ANP lowers blood pressure in the absence of detected changes in renal function; ANP is not essential for normal salt balance, even on high-salt intake; and ANP is essential for the natriuretic response to acute blood volume expansion on a low-salt but not high-salt intake.

Effect of 764-3 on aggregation and calcium movements in aequorin-loaded human platelets

Washed human platelets were loaded with the Ca(2+)-sensitive photoprotein, aequorin, using hypoosmotic shock treatment-technique. Then aggregation and cytoplasmic ionized calcium concentration ([Ca2+]i) changes in response to collagen or thrombin were measured simultaneously in the aequorin-loaded human platelets with a Platelet Ionized Calcium Aggregometer. 764-3, an active component isolated from the Chinese medicinal herb Salvia Miltiorrhiza Bge, inhibited platelet [Ca2+]i rise as well as aggregation evoked by collagen or thrombin in the presence of extracellular Ca2+. After the extracellular Ca2+ was removed by addition of EGTA, collagen or thrombin, causing no aggregation, still elicited platelet [Ca2+]i rise which reflected Ca2+ mobilization from intraplatelet stores. Under this condition, 764-3 could also suppress platelet [Ca2+]i rise. Analysis shows that 764-3 inhibits platelet Ca2+ influx and Ca2+ mobilization with similar potency, which accounts for its suppression of platelet [Ca2+]i rise, and must contribute to its inhibition of platelet aggregation.

[Experimental study of human micro-urokinase gene therapy]

OBJECTIVE

To determine the feasibility and efficiency of gene therapy to thrombotic disease.

METHODS

The retroviral vectors containing 982 bp mUKcDNA were constructed and transfected into PA317 viral packaging cells. Recombinant retroviral particles collected from media of PA317 cells were injected into mice subcutaneous tissue, abdominal cavity and quadriceps muscle, respectively. mUK activity of plasma was measured with a synthetic substrate S-2390. Six mice were sacrificed after injection for immunofluorohistochemical staining.

RESULTS

The mUK activity in plasma was obviously increased (P < 0.01) and the expression of mUKcDNA was observed at local sites of injection by immunofluorohistochemical staining. The mUK activity was raised for 4 months.

CONCLUSION

The injection of recombinant viral particles containing transcriptional unit of mUKcDNA might be applied to the prevention and treatment of thrombotic disease.

Pharmacological and developmental evidence that the potassium-induced stimulation of deoxyglucose uptake in astrocytes is a metabolic manifestation of increased Na(+)-K(+)-ATPase activity

There is disagreement in the literature whether or not deoxyglucose accumulation, a measure of glycolytic activity, is increased in astrocytes during exposure to elevated concentrations of the potassium ion (K+). In the present work we have confirmed our previous finding that deoxyglucose accumulation in primary cultures of well-differentiated mouse astrocytes shows a robust increase when the K+ concentration in the incubation medium is raised to or above 12 mM. This response is inhibited by ouabain (with a half-maximum effect at approximately 0.1 mM), indicating that it is a metabolic manifestation of the activity of an Na(+)-K(+)-ATPase. The stimulation at this high level of K+ indicates a remarkably low K+ affinity of the Na(+)-K(+)-ATPase involved, enabling it to be activated by above-normal concentrations of K+. At a resting concentration of K+ (5.4 mM), at least one half of the deoxyglucose accumulation is also a reflection of Na(+)-K(+)-ATPase activity, as shown by its susceptibility to inhibition by ouabain. Ouabain has some effect even at a concentration of 0.1 microM, indicating participation of not only the alpha 1 isoform which has a low affinity to ouabain, but also of the alpha 2 isoform, which has a high affinity. The stimulatory effect of elevated K+ is absent in immature astrocytes and only develops after prolonged time in culture. It could not be evoked in a seemingly similar culture of rat astrocytes, which has previously been shown to lack Na(+)-K(+)-ATPase activity as well as the alpha 2 isoform of the ATPase. This isoform has unequivocally been found to be expressed by astrocytes in situ.

Astrocyte-neuron interaction during one-trial aversive learning in the neonate chick

During two specific stages of the Gibbs-Ng model of one-trial aversive learning in the neonate chick, we have recently found unequivocal evidence for a crucial involvement of astrocytes. This evidence is metabolic (utilization of the astrocyte-specific energy store, glycogen, during normal learning and inhibition of memory formation by the astrocyte specific metabolic inhibitors, fluoroacetate and methionine sulfoximine) as well as physiological (abolition of memory formation in the presence of ethacrynic acid, an astrocyte-specific inhibitor of cellular reaccumulation of potassium ions). These findings are discussed in the present review in the framework of a more comprehensive description of metabolic and physiological neuronal-astrocytic interactions across an interstitial (extracellular) space bounded by minute processes from either cell type.

[Characterization of platelet activation induced by CD9 McAbs]

The platelet activation induced by two anti-human platelet P24/CD9 McAbs was investigated. The results showed that the pathways of platelet aggregation induced by the two McAbs (HI117 and SJ9A4) were different and HI117 and SJ9A4 induced the phosphorylation of platelet proteins (40,000 and 20,000) when platelets were activated. However, HI117 did not cause a rise in intracellular Ca2+ concentration in activated platelets in comparison with SJ9A4 and the epitope recognized by HI117 and SJ9A4 was different and this might explain why the two CD9 McAbs played different roles in platelet activation in addition, McAbs HI117 and SJ9A4 could not promote associations of other proteins (eg: GP II b/III a) with P24/CD9 on activated human platelets. All these results indicate that the mechanisms of platelet activation induced by HI117 or SJ9A4 are different from each other. It suggests that CD9 antigen plays an importent and complex role in platelet activation.

Structural differences in the cerebral cortex of healthy female and male subjects: a magnetic resonance imaging study

There are both reproductive and nonreproductive behavioral differences between men and women. Brain regions involved in determining sexual behavior have been reported to differ between the sexes. Nonreproductive, cognitive functional differences between sexes might be reflected in higher-order cortical structural dimorphisms, which have not previously been studied. We hypothesized that cortical regions involved in verbal behavior (which is sexually dimorphic) would differ between sexes. Using magnetic resonance imaging, we assessed gray matter volumes in several cortical regions in 17 women and 43 men. Women had 23.2% (dorsolateral prefrontal cortex) and 12.8% (superior temporal gyrus) greater gray matter percentages (corrected for overall brain size and age) than men in a language-related cortical region, but not in a more visuospatially related cortical region. These data seem to establish sexually dimorphic structural differences in the cerebral cortex, consistent with prior cerebral blood flow reports.

Morphometric analysis of spinous cell in oral submucous fibrosis. Comparison with normal mucosa, leukoplakia and squamous cell carcinoma

The morphometric analysis of the spinous cell in 16 specimens of oral submucous fibrosis (OSF) was made by using interactive image analysis system (IBAS-II). 19 parameters of the size and shape were chosen, and compared with normal mucosa, leukoplakia, dysplasia and carcinoma. The results indicated that the cell dimensions (area, perimeter, all kinds of diameter) and nuclear cytoplasmic ratio in OSF were between normal mucosa and dysplasia as well as carcinoma. The former showed a progressive decrease (P < 0.01), and the latter showed a progressive increase (P < 0.01). The dimensions of the nuclei did not show considerable differences among the groups (P < 0.05). A series of discriminant functions had been developed with stepwise discriminant analysis, the agreement ratio for OSF was 93.75%. The decrease of cell area and the increase of nuclear cytoplasmic ratio could reflect a malignant progress. The cell morphometric model could discriminate OSF well from other groups, suggesting that the change of the epithelium in OSF appearing in the spinous cell is specific itself.

Further evidence that fluoxetine interacts with a 5-HT2C receptor in glial cells

It is generally believed that the antidepressant drug fluoxetine (Prozac) exerts all its effects by inhibition of serotonin uptake into neurons and an ensuing increase in the extracellular concentration of serotonin. However, these studies have confirmed and expanded our previous observation that fluoxetine on its own exerts agonist effects on astrocytes (a glial cell type), which resemble those exerted by serotonin. Fluoxetine appears to act on a different subtype of receptor (the 5-HT2C receptor [in original terminology the 5-HT1C receptor]) than the one on which micromolar concentrations of serotonin are known to act in astrocytes (the 5-HT2A receptor [in original terminology the 5-HT2 receptor]). However, this study has shown that application of serotonin to these cells stimulates glycogenolysis and causes an increase in free cytosolic concentration of calcium that is not inhibited by the 5-HT2A selective antagonist, ketanserin. Moreover, both effects are pronounced at the low nanomolar level of serotonin and, therefore, by definition, act on the 5-HT2C receptor. The concentration/response correlation is identical for the serotonin effects on free cytosolic calcium concentration and on glycogenolysis. Fluoxetine exerts similar effects, but low nanomolar concentrations have no effect, and the concentration required to obtain half-maximum response is 1-3 microM, a concentration dependence that is consistent with the plasma levels of fluoxetine during treatment with this drug.(ABSTRACT TRUNCATED AT 250 WORDS)

Distribution of red cell blood group systems in Achang and De'ang ethnic groups in China

A survey on the distribution of red cell group systems, including ABO, MNSs, Rhesus and P, was carried out in the Achang and De'ang ethnic groups in Yunnan Province, South-West China. The Achangs are characterized by the highest frequency of IA in China, while the De'angs show a high frequency of IO and CDe. The distribution of these blood group systems in Achang and De'ang exhibits the same characteristics observed in other ethnic groups of South China.

High extracellular potassium concentrations stimulate oxidative metabolism in a glutamatergic neuronal culture and glycolysis in cultured astrocytes but have no stimulatory effect in a GABAergic neuronal culture

Rates of deoxyglucose accumulation and of CO2 production from [U-14C]glucose, or from [U-14C]lactate or [2-14C]pyruvate (as a determination of tricarboxylic acid (TCA) cycle activity) were determined in primary cultures of either astrocytes, cerebellar granule cell neurons (utilizing glutamate as their transmitter) or cerebral cortical interneurons (utilizing GABA as their transmitter) during control ('resting') conditions and during exposure to an elevated extracellular potassium concentration, mimicking functional activity. The elevation of the extracellular potassium concentration increased the rate of deoxyglucose accumulation, but not of TCA cycle activity in astrocytes and both deoxyglucose accumulation and TCA cycle activity in cerebellar granule cells, but had no stimulatory effect in cerebral cortical neurons. Based on these observations it is suggested that the increase in energy metabolism in the CNS in vivo during functional activity mainly reflects increased active accumulation of potassium ions and extrusion of sodium ions in neurons receiving excitatory input and in adjacent astrocytes in order to re-establish pre-stimulus ion distribution across cell membranes.

Molecular cloning, expression and mutagenesis of an anti-insulin single chain Fv (scFv)

The immunoglobulin variable region genes of a murine anti-insulin IgG-producing hybridoma were rescued and cloned into a bacterial expression vector. The variable regions of the gamma heavy chain and the kappa light chain were expressed independently and together as a single chain antibody (scFv). The variable heavy chain alone demonstrated the ability to bind to insulin. The kappa light chain did not show any binding activity towards insulin. The scFv was constructed by PCR assembly using a (Gly4Ser)3 linker between the carboxyl end of the variable heavy chain and the amino terminus of the kappa light chain. The scFv bound insulin at an IC50 of 3.5 x 10(-8) M whereas the parent antibody bound insulin at 1.0 x 10(-8) M. Mutagenesis of the variable heavy chain complementarity determining regions (CDR) indicated that CDR1 and CDR3 were important for binding to insulin. Position 99 in CDR3 of the heavy chain was found to be a critical position for the ability of the scFv to bind to insulin.

Plasma interleukin-1 alpha and beta, tumor necrosis factor-alpha, and lipopolysaccharide concentrations during pulmonary exacerbations of cystic fibrosis

Earlier studies have reported the presence of interleukin-1 (IL-1) and tumor necrosis factor (TNF) in the plasma of patients with cystic fibrosis (CF), but the results have been inconsistent. To investigate the relationships among plasma IL-1 alpha, IL-1 beta, TNF, lipopolysaccharide (LPS), and clinical status, measurements were made before and after 14 days of intravenous antibiotic therapy in 13 patients with CF. In addition, whole blood cytokine production rates were measured in 18 hr cultures stimulated with 10 micrograms/mL LPS or sterile saline (control). On admission, patients with CF had significantly greater plasma levels of LPS and IL-1 alpha compared with 20 healthy adult controls. In response to antibiotic therapy, the patients had statistically significant increases in weight, oxygen saturation, chest radiograph score, and forced expiratory volume in 1 second. They had significant decreases in pulse rate, residual volume/total lung capacity ratio, white blood count, neutrophil count, LPS concentration, and resting energy expenditure per kg body weight. There were no significant changes in the plasma concentrations of IL-1 alpha, IL-1 beta, or TNF and no significant changes in the basal or stimulated whole blood production rates of IL-1 alpha, IL-1 beta, or TNF. The immunological variables did not correlate significantly with clinical measurements of severity or the presence of fever. It is likely that in CF local pulmonary effects of cytokines are of more pathophysiologic significance than systemic effects.

Photochemical labeling of membrane-associated and channel-forming domains of proteins directed by energy transfer

Singlet-singlet energy transfer reactions from excited tryptophan residues to photoactivatable probes possessing a suitable chromophore, generate reactive species in the vicinity of the protein, leading to its covalent labeling. This delayed labeling process can be used to map the membrane-surrounded regions of proteins with improved efficiency when it is applied with appropriate photoactivatable phospholipids. The same principle could also be applied to the labeling of channel-forming transmembrane domains of ion channels, provided that suitable photoactivatable permeant ions were available. Both applications will be discussed with regard to their potential and feasibility.

Alteration in oxidative metabolism of alanine in cerebellar granule cell cultures as a consequence of the development of the ability to utilize alanine as an amino group donor for synthesis of transmitter glutamate

Formation of 14CO2 from labeled alanine was measured in cultured cerebellar granule cells grown in the combined presence of alanine, alpha-ketoglutarate and glutamine or in the presence of glutamine alone. This was done in order to study whether the utilization of alpha-ketoglutarate plus alanine as precursors of transmitter glutamate, induced by culturing in the presence of these compounds, is reflected by an increase of CO2 production from alanine during stimulation with an elevated extracellular potassium concentration. Potassium stimulated CO2 production from alanine was present only in the cells grown in the combined presence of alanine, alpha-ketoglutarate and glutamine. This stimulation was abolished by glutamine, but not by ouabain, indicating that the depolarizing-induced stimulation of alanine metabolism is a consequence of increased release of transmitter glutamate formed from alanine, not a simple result of an increased metabolic rate.

Uptake, release, and metabolism of citrate in neurons and astrocytes in primary cultures

Synthesis, uptake, release, and oxidative metabolism of citrate were investigated in neurons and astrocytes cultured from cerebral cortex or cerebellum. In addition, the possible role of citrate as a donor of the carbon skeleton for biosynthesis of neurotransmitter glutamate was studied. All cell types expressed the enzyme citrate synthase at a high activity, the cerebellar granule neurons containing the enzyme at a higher activity than that found in the astrocytes from the two brain regions or the cortical neurons. Saturable citrate uptake could not be detected in any of the cell types, but the astrocytes, and, in particular, those of cerebellar origin, had a very active de novo synthesis and release of citrate (approximately 70 nmol x h-1 x mg of protein-1). The rate of release of citrate from neurons was < 5% of this value. Using [14C]citrate it could be shown that citrate was oxidatively metabolized to 14CO2 at a modest rate (approximately 1 nmol x h-1 x mg-1 of protein) with slightly higher rates in astrocytes compared with neurons. Experiments designed to investigate the ability of exogenously supplied citrate to serve as a precursor for synthesis of transmitter glutamate in cerebellar granule neurons failed to demonstrate this. Rather than citrate serving this purpose it may be suggested that astrocytically released citrate may regulate the extracellular concentration of Ca2+ and Mg2+ by chelation, thereby modulating neuronal excitability.

Cell death in primary cultures of mouse neurons and astrocytes during exposure to and 'recovery' from hypoxia, substrate deprivation and simulated ischemia

Effects of hypoxia, substrate deprivation and simulated ischemia (combined hypoxia and substrate deprivation) on cell survival during the insult itself and during a 24 h 'recovery' period were studied in primary cultures of mouse astrocytes and in cerebral cortical neuronal-astrocytic co-cultures. Cell death was determined by release of the cytosolic high molecular enzyme lactate dehydrogenase (LDH) as well as morphologically (retention of staining with rhodamine 123 and lack of staining with propidium iodide as an indicator of live cells). Glutamate concentrations were measured in the incubation media at the end of the metabolic insults. Astrocytes were very resistant to hypoxia, but less so to simulated ischemia; under both conditions the glutamate concentrations in the media remained low. Cerebral cortical neurons were almost equally susceptible to damage by hypoxia and by simulated ischemia, although hypoxia had a faster deleterious effects on some of the neurons and simulated ischemia during a long-term insult (9 h) killed all neurons, whereas a non-negligible neuronal subpopulation survived 9 h of hypoxia. Neuronal cell death after long-term hypoxia (but not after simulated ischemia) was correlated with high concentrations of glutamate in the incubation media. After certain insults, most notably relatively short lasting simulated ischemia (3 h) in neurons (which caused no increased cell death during the insult), there was a large release of LDH during the 'recovery' period.

Signalling effect of elevated potassium concentrations and monoamines on brain energy metabolism at the cellular level

The effects of elevated K+ concentrations and monoamine transmitters on different cell types in the CNS and on different subcellular structures in these cells are reviewed. Pronounced differences exist in the metabolic processes that are stimulated by excess K+ and by adrenergic agonists, e.g., noradrenaline. An elevation in the extracellular K+ concentration appears to enhance neuronal-astrocytic interaction by stimulating metabolic processes involved in (1) the promotion of supply of precursors for transmitter glutamate, and (2) reestablishment of resting ion distribution following neuronal excitation. The monoamine transmitters stimulate energy production and Na+,K(+)-ATPase activity in astrocytes in a complex manner and, in so doing, facilitate their role in ion regulation. However, in contrast to excess K+, they do not enhance the production of astrocytic precursors for neuronal glutamate production. Emphasis is placed on possible profound differences in metabolic effects on excitatory and inhibitory neurotransmission and on the importance of stimulation of glycolytic metabolism in astrocytes versus oxidative metabolism in neurons.

Potassium-induced stimulation of oxidative metabolism of glucose in cultures of intact cerebellar granule cells but not in corresponding cells with dendritic degeneration

Production of 14CO2 from uniformly labelled glucose was measured in conventional cultures of mouse cerebellar granule cells (a glutamatergic cell type) and in corresponding cultures which had been grown in such a manner that they showed massive degeneration of dendrites, but were otherwise morphologically normal. Both kind of cultures were studied during exposure to either a physiological potassium concentration (5 mM) or an elevated extracellular potassium concentration. During exposure to the normal extracellular potassium concentration, the rate of CO2 production in the two types of culture was identical. In the conventional granule cell cultures, the CO2 production showed a rectilinear increase as a function of the extracellular potassium concentration from 5-100 mM; this stimulation was abolished by ouabain, a specific inhibitor of Na+,K(+)-ATPase. In granule cells showing dendritic degeneration, CO2 production increased only slightly at extracellular potassium concentrations of 25-100 mM. These findings suggest that the metabolic stimulation in morphologically intact cells may be the result of a depolarization-induced sodium uptake, which has a mainly or exclusively dendritic localization, and secondarily leads to a stimulation of the Na+,K(+)-ATPase at its intracellular sodium-sensitive site.

Stimulation of glycogenolysis in astrocytes by fluoxetine, an antidepressant acting like 5-HT

Fluoxetine is a recently introduced, widely used antidepressant. It is known as a specific inhibitor of serotonin uptake into synaptosomes but has not previously been recognized as having any direct effect on brain cell serotonin receptors. The present study describes direct effects of fluoxetine on free cytosolic calcium concentration and on breakdown of glycogen in astrocytes (a glial cell type), which are known to express serotonin receptors. Evidence is presented, suggesting that these effects are evoked by an agonist action on the 5-HT1C receptor.

Comparison of amino acid sequences of the trypsin inhibitors from taro (Colocasia esculenta), giant taro (Alocasia macrorrhiza) and giant swamp taro (Cyrtosperma chamissonis)

The amino acid sequences of the trypsin inhibitors from taro Colocasia esculenta var. esculenta and giant swamp taro Cyrtosperma chamissonis have been determined and are compared with the protein sequence of the trypsin/chymotrypsin inhibitor from giant taro Alocasia macrorrhiza. Both inhibitors display polymorphism and there is evidence of two components in the giant swamp taro. The positional identity between the proteins is highest at 73-75% for the comparison of the giant taro (GT) with the polymorphic forms of the taro (T) inhibitors and lowest at 56-58% for the pairs of taro and giant swamp taro (GST) proteins. The comparisons show that the inhibitors from T and GT are more related to each other than to GST, which supports their taxonomic classification into different tribes. Location of the P1 site for the trypsin inhibitors of aroids is different from that of other Kunitz-type inhibitors and could be at Leu56.