Preliminary X-ray crystallographic study of methyltetrahydrofolate: corrinoid/iron sulfur protein methyltransferase fromClostridium thermoaceticum

Methyltetrahydrofolate:corrinoid/iron sulfur protein methyltransferase from Clostridium thermoaceticum has been crystallized in two polymorphic forms and characterized by X-ray diffraction measurements. Form I displayed orthorhombic symmetry with a = 63.9, b = 53.8, c = 164.0 A. Form II also displayed orthorhombic symmetry with a = 63.5, b = 87.1, c = 117.9 A. Crystals of form I diffract to approximately. 3 A resolution; those of form II diffract to approximately 2.7 A.

Cloning and nucleotide sequence of a gene upstream of the eaeA gene of enterohemorrhagic Escherichia coli O157:H7

A DNA segment located immediately upstream of the eaeA gene of enterohemorrhagic Escherichia coli O157:H7 strain HA1 was cloned and sequenced. This segment contained an open reading frame encoding a predicted protein of 156 amino acids. A database search identified similar open reading frames upstream of the eaeA gene in two other bacterial pathogens, i.e. enteropathogenic E. coli and Citrobacter freundii. The predicted amino acid sequence of the enterohemorrhagic E. coli protein shared 96.8% and 94.2% identity with the enteropathogenic E. coli and C. freundii sequences, respectively. Because the open reading frame is located within the locus of enterocyte effacement region of the E. coli chromosome, a 'hot spot' for insertion of virulence factor genes, and shares high sequence homology with attaching and effacing EPEC and C. freundii, this protein may be associated with pathogenicity of E. coli O157:H7.

Synergistic effects of fluid shear stress and cyclic circumferential stretch on vascular endothelial cell morphology and cytoskeleton

The development of atherosclerosis is thought to be initiated by a dysfunctional state of the vascular endothelium. The proposal that mechanical forces play a role in the localization of this disease has led researchers to develop in vitro models to assess their effects on cultured endothelial cells. The arterial endothelium is exposed simultaneously to circumferential hoop stretch and wall shear stress, yet previous investigations have focused on the isolated effects of either cyclic stretch or shear stress. The influence of physiological levels of combined shear stress and hoop stretch on the morphology and F-actin organization of bovine aortic endothelial cells was investigated. Cells subjected for 24 hours to shear stresses higher than 2 dyne/cm2 or to hoop stretch greater than 2% elongated significantly compared with unstressed controls and oriented along the direction of flow and perpendicular to the direction of stretch. Exposure to more than 4% stretch significantly enhanced the responses to shear stress. Both shear stress and hoop stretch induced formation of stress fibers that were aligned with the cells' long axes. Simultaneous exposure to both stimuli appeared to enhance stress fiber size and alignment. These results indicate that shear stress and hoop stretch synergistically induce morphological changes in endothelial cells, which suggests that circumferential strain might modulate sensitivity of endothelial cells towards shear stress.

Correlation of Rhs elements with Escherichia coli population structure

The Rhs family of composite genetic elements was assessed for variation among independent Escherichia coli strains of the ECOR reference collection. The location and content of the RhsA-B-C-F subfamily correlates highly with the clonal structure of the ECOR collection. This correlation exists at several levels: the presence of Rhs core homology in the strain, the location of the Rhs elements present, and the identity of the Rhs core-extensions associated with each element. A provocative finding was that an identical 1518-bp segment, covering core-extension-b1 and its associated downstream open reading frame, is present in two distinct clonal groups, but in association with different Rhs elements. The sequence identity of this segment when contrasted with the divergence of other chromosomal segments suggests that shuffling of Rhs core extensions has been a relatively recent variation. Nevertheless the copies of core-extension-b1 were placed within the respective Rhs elements before the emergence of the clonal groups. In the course of this analysis, two new Rhs elements absent from E. coli K-12 were discovered: RhsF, a fourth member of the RhsA-B-C-F subfamily, and RhsG, the prototype of a third Rhs subfamily.

Yishou jiangzhi (de-blood-lipid) tablets in the treatment of hyperlipemia

The Yishoujiangzhi (de-blood-lipid) tablets (composed of Radix Polygori Multiflori, Rhizoma Polygonati, Fructus Lycii, Crataegus Pinnatifida and Cassia Tora) were used in the treatment of 130 cases of hyperlipemia, achieving an effective rate of 87.0% in lowering serum cholesterol and 80.8% in lowering triglyceride.

Identification of Babesia bovis merozoite antigens separated by continuous-flow electrophoresis that stimulate proliferation of helper T-cell clones derived from B. bovis-immune cattle

To characterize Babesia bovis merozoite antigens that stimulate anamnestic T helper (Th)-cell responses from B. bovis-immune cattle, B. bovis-specific Th-cell lines and clones, previously assigned to different antigenic groups (W. C. Brown, S. Zhao, A. C. Rice-Ficht, K. S. Logan, and V. M. Woods, Infect. Immun. 60:4364-4372, 1992), were tested in proliferation assays against fractionated merozoite antigens. The antigenic groups were determined by the patterns of response of Th clones to different parasite isolates and soluble or membrane forms of merozoite antigen. Soluble antigen fractionated by anion-exchange chromatography or gel filtration by using fast-performance liquid chromatography resolved two or three antigenic peaks, respectively. To enable fractionation of membrane-associated proteins and to resolve more precisely the proteins present in homogenized merozoites, a novel technique of continuous-flow electrophoresis was employed. Merozoite membranes or whole merozoites were homogenized and solubilized in sodium dodecyl sulfate-sample buffer, electrophoresed under reducing conditions on 15% or 10% acrylamide gels, eluted, and collected as fractions. Individual fractions were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and tested for the ability to stimulate Babesia-specific CD4+ T-cell lines and clones. CD4+ Th-cell lines from two cattle displayed differential patterns of reactivity and detected numerous peaks of antigenic activity, ranging from < 14 to 76 kDa. Th-cell clones previously categorized into different antigenic groups detected antigenic peaks unique for clones representative of a given group. Antigens of 29, 51 to 52, and 85 to 95 kDa (group I), 40 kDa (group III), 20 kDa (group IV), 58 to 60 kDa (group VI), and 38, 45, and 83 kDa (group VII) were identified in the stimulatory fractions. Immunization of rabbits with selected fractions produced a panel of antisera that reacted specifically on Western blots (immunoblots) with merozoite antigens of similar sizes, leading to the tentative identification of candidate antigens of B. bovis merozoites with molecular masses of 20, 40, 44, 51 to 52 or 95, and 58 to 60 kDa that stimulate proliferation of Th clones representative of five different antigenic groups. These antisera may be useful for isolating recombinant proteins that are immunogenic for Th cells of immune cattle and therefore potentially useful for vaccine development.

An immunocytochemical study on relations between mast cell and peptidergic terminals in nasal mucosa of chronic rhinitis patients

Mast cell-nerve relation is a new topic explored deeply in different organs, but little documentation could be found in the literature on the relation in human nasal mucosa. We carried out this study using immunocytochemistry and found that substance P (SP) terminals were present in human nasal mucosa from six cases of chronic rhinitis. SP terminals were often found to be adjacent to or have a direct contact with mast cells (MCs). Electron-microscopic studies revealed that MCs could contact nonmyelinated nerve terminals. These results have important implications in the understanding of the pathogenesis of neurogenic inflammation seen in nasal mucosa and will probably cast new insight into the future treatment of such disease.

[Inclusion compounds of jiuxin oil with beta-cyclodextrin]

The inclusion compounds of Jiuxin Oil with beta-cyclodextrin were prepared. The influence of temperature, ratio of host and guest molecules, stirring time on inclusion were observed. The quantitative determination was performed by gas chromatography. Inclusion compounds of Jiuxin Oil were confirmed by differential scanning calorimetry and powder X-ray diffractometry.

Low-level direct electrical current therapy for hepatic metastases. I. Preclinical studies on normal liver

Low-level direct electrical current has shown promise as a potential therapeutic modality (direct current therapy; DCT) in the treatment of malignant disease, including metastases, but to date much experimental work has been empirical and has added little to our knowledge of the mechanisms involved. As a prerequisite to a clinical trial for metastases in the liver, we have employed an in vivo liver model to examine the quantitative and qualitative relationships between electrode polarity, charge and tissue necrosis. Two distinct regions of necrosis were induced, distinguishable histologically and by magnetic resonance imaging: (i) a cylindrical region of primary necrosis centred on the electrode, its volume directly proportional to the charge passed, but greater at the anode than cathode; and (ii) a wedge-shaped infarct, apex at the electrode and base extending to the liver edge. The extent of this infarct was again greater at the anode than the cathode, but showed a sigmoidal relationship with charge. Results indicate pH changes at the electrodes as likely mediators of tissue injury, but show also that significant distant ischaemic injury can occur as a consequence of primary damage. These findings should be considered when selecting tumours for possible direct current therapy and when determining the sites of electrode placement.

A highly conserved nuclear gene for low-level phylogenetics: elongation factor-1 alpha recovers morphology-based tree for heliothine moths

Molecular systematists need increased access to nuclear genes. Highly conserved, low copy number protein-encoding nuclear genes have attractive features for phylogenetic inference but have heretofore been applied mostly to very ancient divergences. By virtue of their synonymous substitutions, such genes should contain a wealth of information about lower-level taxonomic relationships as well, with the advantage that amino acid conservatism makes both alignment and primer definition straightforward. We tested this postulate for the elongation factor-1 alpha (EF-1 alpha) gene in the noctuid moth subfamily Heliothinae, which has probably diversified since the middle Tertiary. We sequenced 1,240 bp in 18 taxa representing heliothine groupings strongly supported by previous morphological and allozyme studies. The single most parsimonious gene tree and the neighbor-joining tree for all nucleotides show almost complete concordance with the morphological tree. Homoplasy and pairwise divergence levels are low, transition/transversion ratios are high, and phylogenetic information is spread evenly across gene regions. The EF-1 alpha gene and presumably other highly conserved genes hold much promise for phylogenetics of Tertiary age eukaryote groups.

Modification of IFSSH system for evaluation of impairment of hand function

We modified the examination and evaluation standard of impairment of hand function proposed by the International Federation of Societies for Surgery of the Hand (IFSSH). 1) The thumb adduction and opposition examination is changed from measuring distance alone to calculation of the ratio of thumb length to the distance of movement. 2) Sensation grading and two-point discrimination test are included in the sensory function evaluation. 3) In the estimation of anatomic loss of the hand, instead of measuring the length of the loss, calculation of the area of loss is proposed. 4) In the evaluation of joint movement, besides the angle of movement and position of the joint itself, influence of the defect distal to the joint thereon is also considered. 5) In the original evaluation standard, sensory disturb ances of the palmar and dorsal aspects of the hand as well as the anatomic loss of tissues through the palm are not taken into account. The present work pays special attention to this point. The software of the above mentioned work has been developed, approved by experts and adopted nation wide in China. The data of hand function examinations can be fed into the computer and the function loss in percentage can be displayed, or printed out. This software, using a graphic display, can also take care of the filling and retrieving of case history. At present the menu and instructions are in Chinese, which can be changed to suit other language.(ABSTRACT TRUNCATED AT 250 WORDS)

Low incidence of MDR1 expression in acute promyelocytic leukaemia

The MDR1 gene product, P-glycoprotein, functions as a transmembrane efflux pump for certain cytotoxic agents including anthracyclines. Based upon the clinical observation that patients with acute promyelocytic leukaemia (APL) respond favourably to anthracyclines, we hypothesized that APL cells may have low levels of MDR1 expression. We therefore investigated MDR1 expression in 10 patients with APL and compared results with those obtained in 18 patients with other subtypes of acute myelogenous leukaemia (AML). Prior to reverse transcriptase polymerase chain reaction with MDR1 specific primers, leukaemic cells were purified by fluorescence activated cell sorting to exclude normal haemopoietic cells, in particular lymphocytes, from the MDR1 analysis. In sorted APL cells, MDR1 expression was detected in only two of 10 patients, which was significantly different from findings in other AML subtypes (MDR1 expression in 14/18 patients; P < 0.01). When unsorted specimens from APL patients were studied, five of six cases were MDR1 positive, whereas sorted APL cells were shown to express MDR1 mRNA in only one of these cases. MDR1 mRNA levels expressed as MDR1/beta-2 microglobulin ratios were significantly lower in APL (0.24 +/- 0.2, mean +/- SD) than in AML (0.75 +/- 0.48; P < 0.01). We conclude that low or absent expression of MDR1 in APL cells may contribute to the efficacy of anthracyclines in the treatment of APL.

The anatomy of the lateral cutaneous nerve of the thigh--a possible donor nerve for facial nerve repair

One hundred anterior branches of the lateral cutaneous nerve of the thigh were dissected and measured in 50 adult cadavers. The results show that this nerve was present in all sides, and the average length from the point of the nerve piercing the fascia lata to the point of its first branch was about 79 mm, the average width was 2.25 mm, and the average thickness was 0.79 mm. It was found that the nerve was approximately along the line between the anterior superior iliac spine and the midpoint of the upper margin of the patella. This study presents a simple method of locating this nerve for clinical reference. The results also reveal that this nerve is a possible donor for facial nerve repair.

Laser characteristics of low-threshold high-efficiency Nd:Sr(5)(VO(4))(3)F crystal

The absorption spectrum of a new crystal, Nd:Sr(5)(VO(4))(3)F (Nd:S-VAP), was measured, which showed that Nd:S-VAP can be suitably pumped at 583.0 and 809.0 nm as well as with a xenon f lash lamp. With a tunable dye laser (570-600 nm) and a xenon f lash lamp as pump sources, respectively, the free-running and Q-switched outputs with BDN dye film were realized at 1.065 microm. For the tunable dye-laser pump source the threshold energy is 2 mJ and the slope eff iciency is 50%, while for the xenon f lash-lamp pump source the lowest threshold energy is 130 mJ and the highest slope efficiency is 1.3%. The laser characteristics, such as the emission spectrum, the polarization, the output energy, and the pulse width, were measured. In addition, the prospect of a Nd:S-VAP crystal for low-threshold, high-efficiency miniature lasers is discussed.

Decreased expression of the deleted in colorectal carcinoma gene in non-Hodgkin's lymphoma

The putative tumor suppressor gene deleted in colorectal carcinoma (DCC), located on human chromosome band 18q21, is deleted or inactivated in many solid tumors. Its role in the pathogenesis of non-Hodgkin's lymphoma (NHL) has not been studied. Recently, inactivation of this gene was reported in cases of leukemia with monosomy 18. As monosomy 18 is frequently observed in low-grade NHL, we investigated the incidence of altered DCC gene expression in patients with NHL, and correlated it with the number of copies of chromosome 18. Fifteen unselected cases of NHL were studied for evidence of DCC gene expression by reverse transcriptase-polymerase chain reaction. The results were correlated with Southern blot analysis of the DCC gene and with the number of copies of chromosome 18 determined by fluorescent in situ hybridization (FISH). The controls were tissues from normal colon mucosa and normal tonsils. Eight of 15 (53%) NHL cases lacked DCC mRNA, and one expressed substantially less than normal. Southern blot analysis showed normal configuration of the DCC gene in all samples. Two copies of chromosome 18 were found in 9 of 11 samples studied by FISH: one case had a subpopulation of cells with monosomy 18 and one had trisomy 18. All controls expressed DCC. We conclude that DCC gene expression is frequently absent or decreased in NHL and may be involved in the pathogenesis of NHL. Monosomy 18 was not required for DCC inactivation.

New primer strategy improves precision of differential display

To increase the reproducibility and to reduce the false positives in the initial mRNA differential display, modified long composite primers were developed based on both mRNA differential display and RNA arbitrarily primed PCR fingerprinting methods. Ten-base nucleotides were added at the 5' ends of the primers used in the initial mRNA differential display. These included a restriction site to aid cloning. PCR began with one low-stringency cycle (40 degrees C for annealing) followed by 35 high-stringency cycles (60 degrees C for annealing). The modified method significantly improved the reproducibility and sensitivity of the mRNA differential display while still keeping the characteristics of the original method.

Changes of cellular morphology and nuclear DNA content in different nasopharyngeal epithelium from different patients

Cellular morphology and nuclear DNA content were measured with point-counting technique and flow cytometry (FCM) respectively in normal nasopharyngeal epithelium (NE), tissue adjacent to carcinoma (ATC) and nasopharyngeal carcinoma (NPC). The results showed that all 20 patients with NE showed diploid, whereas 38 (38%) of 101 patients with NPC, 7 (58%) of 12 patients with recurrent NPC, 6 (30%) of 20 patients with ATC and 2 (33%) of 6 patients with NE positive to EBVCA-IgA test showed nondiploid. A total of 19 morphometric parameters of the cell were measured and calculated. The results showed that with malignant transformation of NE, most of the cellular morphometric parameters gradually increased in numerical values while no marked difference was shown between normal NE and simple hyperplasia or metaplasia in terms of cytomorphometric characteristics. Most of the parameters in dysplasia changed significantly as compared with those normal NE, simple hyperplasia or metaplasia and NPC groups. Cytomorphometric analysis seems to give strong support to the concept that dysplasia is among the transitional stages of disease process between normal NE and NPC. Our results show that morphometric analysis and FCM may offer valuable and objective criteria in the early diagnosis of NPC and premalignant disease.

Monoclonal antibodies specific for rat relaxin. VIII. Passive immunization with monoclonal antibodies throughout the second half of pregnancy reduces water consumption in rats

Recent studies demonstrated that exogenous relaxin promoted drinking in nonpregnant rats. The purpose of this investigation was to determine the influence of endogenous relaxin on water consumption in pregnant rats. To that end, a monoclonal antibody specific for rat relaxin, designated MCA1, was used to passively neutralize endogenous relaxin throughout the second half of pregnancy in intact rats. Five milligrams of highly purified MCA1 were administrated iv to rats daily from days 12-22 of pregnancy. Controls received either a monoclonal antibody for fluorescein (monoclonal antibody control) or PBS (vehicle control). The amount of water consumed and both the total duration of water consumption and the total number of episodes when water was consumed were determined daily during both dark and light periods for all treatment groups. From days 13-22 of pregnancy, all three of these parameters of water consumption increased during the 10-h dark period (P < 0.01), but not during the 14-h light period. The mean daily water consumption in MCA1-treated rats was significantly less than that in controls (P < 0.05). Relaxin's effects on water consumption were limited to the 14-h light period (P < 0.01). No difference was found in daily water consumption between the MCA1-treated and control groups during the 10-h dark period. There was a tendency during the light period for both the total duration of water consumption (P = 0.06) and the total number of episodes when water was consumed (P = 0.13) to be less in MCA1-treated rats than in controls. Food consumption and body weight increased as pregnancy progressed, but no differences were found among the three treatment groups. We conclude that endogenous relaxin has effects on water consumption. It promotes water consumption during the daily light period in the second half of pregnancy in rats. Thus, relaxin may be a dipsogenic agent.

[Pharmacological research on antiasthmatic liquid for oral administration]

The Oral Antiasthmatic Liquid, when given into the mice stomach, can obviously reduce the times of cough induced by sulfur dioxide aerosol, and increase the amount of phenolsulfonphthalein excretion of tracheas. It also shows antagonistic action to bistamin phosphate and acetylcholine that can contract the isolated tracheas of guinea-pigs, and reduce the amounts of isolated lung and bronchial perfusion of guinea-pigs.

In vitro transdifferentiation of embryonic rat retinal pigment epithelium to neural retina

Divergence of neural retinal and retinal pigment epithelial (RPE) lineages from the optic vesicle neuroepithelium starts at a very early stage of eye development. Partially or even fully differentiated RPEs of some vertebrate species are capable of transforming into neural retina. In the present study, we have shown that mammalian RPE possesses the ability to transdifferentiate into neural retina at early embryonic stages. If cultured in serum-free medium, presumptive rat RPE became pigmented and expressed a molecular marker of mature RPE. In the presence of basic fibroblast growth factor (bFGF), cultured early embryonic rat RPE did not acquire pigment and grew to form retina-like multilayer structure containing neuronal cells and cells that express markers of retinal ganglion, amacrine and rod photoreceptor cells. The effects of bFGF occurred independently of effects on cell division and became irreversible after periods that varied with tissue age. This study has demonstrated that already differentiated embryonic rat RPE still retain the ability to become neural retina up to certain stage.

[Correlated multiple parameters in pleural effusion with pathology of pleurae for differential diagnosis of tuberculous and carcinomatous pleuritis]

The level of ADA, LZM, leukocyte count, lymphocyte in tuberculous effusion is higher than that of carcinomatous effusion (P < 0.05). All results showed that the change of multiple parameters is related to the pathological manifestation of pleurae. The false positive or negative result was influenced by pathological appearance and bloody character of pleural effusion. Using the ADA, LZM cut off value at 35U and 30mg, respectively, and pleural/serum ADA ratio > 1.4, LZM > 1.1, a sensitivity and specificity of 100 percent were achieved.

Molecular characterisation of Escherichia coli O157:H7 isolates by pulsed-field gel electrophoresis and plasmid DNA analysis

Foods of bovine origin have been identified as sources of Escherichia coli O157:H7. Genomic DNA of E. coli O157:H7 isolates from patients (six isolates), food samples (18 isolates from ground beef and six isolates from raw milk) and calf faecal samples (31 isolates) were characterised by pulsed-field gel electrophoresis (PFGE) and plasmid DNA analysis. These isolates originated from different locations in the USA during 1992 and 1993. Twenty-one distinct genomic profiles were generated from the 61 isolates by PFGE after digestion with the endonuclease XbaI. Four genomic profiles were identified among five patient isolates and the remaining patient isolate was not typable. Five different profiles were detected amongst the isolates from ground beef, one of which was associated with 13 ground beef isolates from an outbreak in the Pacific Northwest of the USA in 1993. The PFGE profile of five calf isolates from Washington and Wisconsin was identical to the profile of the ground beef isolates from the outbreak, suggesting that these isolates were related. Similarly, one PFGE profile accounted for three isolates from calf faeces and one from ground beef. Six raw milk isolates from Georgia were indistinguishable both from each other and from one isolate from calf faeces. Fourteen genomic profiles were identified among 31 calf faecal isolates from 18 different herds in 11 states. Only five plasmid profiles were identified among the 61 isolates. PFGE was shown to be a useful typing technique for E. coli O157:H7.

Reliability and clinical validity of UM-CIDI DSM-III-R generalized anxiety disorder

This is the first in a series of reports on the long-term test-retest reliability and procedural validity of the UM-CIDI, a modified version of the Composite International Diagnostic Interview used in the US National Comorbidity Survey (NCS). This report focuses on DSM-III-R Generalized Anxiety Disorder (GAD). The NCS administered the UM-CIDI to a nationally representative sample of 8098 respondents in the age range 15-54. A subsample of 36 respondents was subsequently selected for clinical reappraisal of GAD, consisting of reinterviewing by a clinical reappraisal interviewer who blindly readministered the GAD section of the UM-CIDI followed by an expanded version of the GAD section of the Structured Clinical Interview for DSM-III-R (SCID). The test-retest reliability of UM-CIDI/DSM-III-R lifetime GAD is Kappa = .53. When the requirement that the worries be excessive or unrealistic (A2) is removed, as in ICD-10 and partially in DSM-IV, reliability increases to Kappa = .78. The concordance between the baseline UM-CIDI diagnosis and the SCID diagnosis is Kappa = .35, while the cross-sectional concordance is Kappa = .47 (.66 when the Criterion A2 requirement is removed). Item-level analysis shows that lack of concordance between the UM-CIDI and the SCID is due largely to Criteria A2 and D. The A2 problem could be addressed either by deemphasizing the cognitive-evaluative component of GAD as in ICD-10, or by removing consideration of the term "unrealistic" from the criterion as in DSM-IV and more clearly specifying the meaning of the term "excessive". These options require further research on similarities and differences in risk factors, course, family history, and treatment response of more narrowly and broadly defined GAD. The Criterion D problem is due to lack of clarity in what constitutes a symptom occurring "often". This is clarified in DSM-IV. It is likely that this clarification will make it possible to develop more precisely structured questions to evaluate Criterion D in subsequent revisions of the UM-CIDI, resulting in improved reliability and validity.

[Anatomical study of anterior branches of the lateral cutaneous nerve of the thigh]

100 anterior branches of the lateral cutaneous nerve of the thigh were dissected and measured in 50 adult cadavers. The results show that this nerve is present in all sides. The average length from the point of the nerve piercing fascia lata to the point of its first branch is about 79mm, the average width is 2.25 mm, and the average thickness is 0.79 mm respectively. It is found that the course of the nerve is approximately along the line between the anterior superior iliac spine and the midpoint of the patella. This study is benifit to the facial nerve grafting in clinic by providing data of the nerve.

Reshuffling of Rhs components to create a new element

RhsF has been identified as the fourth member of the RhsABCF subfamily of genetic elements. This new element is found in Escherichia coli ECOR-50 and several other strains but not in strain K-12. A novel feature of RhsF is that it represents a new arrangement of components previously uniquely associated with RhsA and RhsC of strain K-12.

Identification of candidate vaccine antigens of bovine hemoparasites Theileria parva and Babesia bovis by use of helper T cell clones

Current vaccines for bovine hemoparasites utilize live attenuated organisms or virulent organisms administered concurrently with antiparasitic drugs. Although such vaccines can be effective, for most hemoparasites the mechanisms of acquired resistance to challenge infection with heterologous parasite isolates have not been clearly defined. Selection of potentially protective antigens has traditionally made use of antibodies to identify immunodominant proteins. However, numerous studies have indicated that induction of high antibody titers neither predicts the ability of an antigen to confer protective immunity nor correlates with protection. Because successful parasites have evolved antibody evasion tactics, alternative strategies to identify protective immunogens should be used. Through the elaboration of cytokines, T helper 1-(Th1)-like T cells and macrophages mediate protective immunity against many intracellular parasites, and therefore most likely play an important role in protective immunity against bovine hemoparasites. CD4+ T cell clones specific for soluble or membrane antigens of either Theileria parva schizonts or Babesia bovis merozoites were therefore employed to identify parasite antigens that elicit strong Th cell responses in vitro. Soluble cytosolic parasite antigen was fractionated by gel filtration, anion exchange chromatography or hydroxylapatite chromatography, or a combination thereof, and fractions were tested for the ability to induce proliferation of Th cell clones. This procedure enabled the identification of stimulatory fractions containing T. parva proteins of approximately 10 and 24 kDa. Antisera raised against the purified 24 kDa band reacted with a native schizont protein of approximately 30 kDa. Babesia bovis-specific Th cell clones tested against fractionated soluble Babesia bovis merozoite antigen revealed the presence of at least five distinct antigenic epitopes. Proteins separated by gel filtration revealed four patterns of reactivity, and proteins separated by anion exchange revealed two patterns of reactivity when selected T cell clones were assayed for stimulation by antigenic fractions. Studies using a continuous-flow electrophoresis apparatus have indicated the feasibility of identifying T cell-stimulatory proteins from parasite membranes as well as from the cytosolic fraction of B. bovis merozoites. The Th cell clones reactive with these different hemoparasites expressed either unrestricted or Th1 cytokine profiles, and were generally characterized by the production of high levels of IFN-gamma. A comprehensive study of T cell and macrophage responses to defined parasite antigens will help elucidate the reasons for vaccine failure or success, and provide clues to the mechanisms of acquired immunity that are needed for vaccine development.

[Determination of primaquine and hepatic targeting neoglycoalbumin-primaquine in whole blood and liver of mouse by normalphase high-performance liquid chromatography]

We have developed a method to estimate primaquine (PQ) and hepatic targeting antimalarial agent neoglycoalbumin-primaquine (NGA PQ) in whole blood and liver of mice by sensitive and selective high-performance liquid chromatography. The primaquine was extracted out with ether from the basified biological samples in the PQ diphosphate group or from the samples which were acidic hydrolyzed then basified in NGA-PQ group. The extracts were evaporated under N2 then dissolved in the mobile phase. A linear chain analogue of primaquine was used as the internal standard. The samples were injected into the normal phase silica column with chloroform: methanol:ammonia solution (86.8:12.5:0.7,V/V/V) as mobile phase and detected at 254 nm. The average recovery of the method was 100.09 +/- 3.46 (mean +/- s)%; the CV of within-day and between-day were 2.7%-6.13% (n = 5) and 8.32%-13.56% (n = 9) respectively; in PQ group and NGA-PQ group, the PQ concentrations ranged from 10-20,000 ng/ml blood or 1g. liver respectively, and they all yielded a good linear relationship with the peak height ratios. No endogeneous interference was found in chromatograms of biological samples.

Expression of MDR1 by normal bone marrow cells and its implication for leukemic hematopoiesis

Expression of MDR1 is a well-characterized mechanism leading to resistance of tumor cells to drugs like vinca-alkaloids, anthracyclines, and epipodophyllotoxins. In hematopoiesis, recent data indicate that not only leukemic cells, but also some populations of normal hematopoietic cells, particularly CD34+ progenitor cells as well as peripheral blood lymphocytes, express a functional multidrug-resistant phenotype. Among CD34+ cells, we found evidence that myeloid committed precursor cells (CD34+/CD33+) have lower levels of MDR1 expression than earlier CD34+ cell populations, but there was no difference in MDR1 expression between CD34+/HLA-DR- and CD34+/HLA-DR+ subpopulations. During normal myeloid differentiation, MDR1 expression is down-regulated, which is similar to our observations in acute myelogenous leukemia (AML): MDR1 expression was only rarely detected in acute promyelocytic leukemia, which was in contrast to other subtypes of AML; also, within leukemic subpopulations of the same patient, higher MDR1 levels were correlated with a more immature immunophenotype. Regarding regulation of MDR1 expression, we did not observe changes of MDR1 expression in normal CD34+ cells in response to various cytokines. However, in 2 patients with AML treated with interleukin-3 and granulocyte-colony stimulating factor, respectively, a significant down-regulation of MDR1 expression was found after 24 hours. In conclusion, there is evidence that the pattern of MDR1 expression observed in leukemias reflects the distribution of MDR1 in normal hematopoiesis. In contrast to normal CD34+ cells, leukemic cells from some AML patients can respond to cytokines with a down-regulation of MDR1, which may contribute to response to cytokine/chemotherapy combinations.

[Detection of hypermethylation in affected males with fragile X syndrome by PCR assay]

PCR technique was applied to detect hypermethylation at BssH II recognition sites within CpG island of FMR-1 gene in normal, affected, and clinically suspected males with fragile X syndrome. Hypermethylation was found to occur in all 7 affected and 5 of 26 suspected, but none of 15 normal males. The results of PCR assay are in good coincidence with those of Southern blot and cytogenetic assays. This PCR assay will be a promising method in the diagnosis of fragile X syndrome in males with mental retardation.

[Rectal administration of ash bark]

A TLC-densitometric method was applied to determine aesculin in rabbit blood. The best way for ash bark rectal administration was found by orthogonal design [L4(2(3))]. The two routes of administration (per rectal, P.O.) were compared by bioavailabilities and the result indicated that per rectal was better than P.O. Modified isolated rectum-bag method was applied successfully to finding the best way for rectal administration of ash bark.

[Research on rectal administration of bark of official Magnolia]

Fluorescence assay was applied to the determination of magnolol in rabbit blood, and the best way to administer the bark of official magnolia per rectal was established by orthogonal test. Then the two routes of administration were compared by AUC of magnolol and per rectal was found better than P.O. In addition, the modified isolated rectum-bag method was applied successfully to the research on rectal administration of bark of official magnolia.

Granulocyte-colony stimulating factor, granulocyte-macrophage colony stimulating factor, PIXY-321, stem cell factor, interleukin-3, and interleukin-7: receptor binding and effects on clonogenic proliferation in acute lymphoblastic leukemia

Cytokines are frequently used after chemotherapy of leukemias and solid tumors to augment recovery of normal hematopoiesis. While the regulation of normal and leukemic myelopoiesis is well investigated, little is known about effects of cytokines on growth and differentiation of lymphoblastic leukemia. In this study, we investigated the expression of receptors for G-CSF, GM-CSF, SCF, IL-3, and IL-7 on acute lymphoblastic leukemia (ALL) blasts and the effects of these growth factors (GF) on ALL blast colony formation. The binding of fluorescence-tagged cytokines to receptors on ALL blasts was studied by flow-cytometry in 27 cases of ALL (24 precursor B-ALL, 3 T-ALL). Receptor-binding for myeloid-associated GF was observed in the majority of precursor B-ALL (G-CSF = 100%, GM-CSF = 65%, IL-3 = 83%, SCF = 74%), but not in T-ALL. Binding of labelled IL-7 was detected in both precursor B- (92%) and T-ALL (100%). The presence of receptors for SCF in ALL was confirmed by polymerase chain reaction for c-kit mRNA in 19/21 cases tested. Expression of receptors for G-CSF, GM-CSF, IL-3, and SCF was not associated with expression of myeloid antigens, or with specific cytogenetic abnormalities. The effects of these GF on clonogenic cells were tested in the ALL blast colony assay and varied between samples, but all cytokines were able to increase clonogenic growth. The GM-CSF/IL-3 fusion molecule PIXY-321 was most effective in promoting colony growth. In some cases inhibition of colony formation was found. We conclude that ALL blast cells have receptors not only for IL-7, but also for G-CSF, GM-CSF, SCF, and IL-3. ALL precursors can respond to these GF with changes in their clonogenic growth indicating the presence of functional receptors. Results may have implications for therapeutic approaches combining cytokines and chemotherapy.

Epitope mapping of the branched chain alpha-ketoacid dehydrogenase dihydrolipoyl transacylase (BCKD-E2) protein that reacts with sera from patients with idiopathic dilated cardiomyopathy

Sera from 29 of 48 patients with idiopathic dilated cardiomyopathy (IDCM) and six of six patients with dilated cardiomyopathy (DCM) secondary to suspected viral myocarditis were shown to react with the branched chain alpha-ketoacid dehydrogenase (BCKD) complex mitochondrial proteins. Whereas sera from only 1 of 26 patients with ischemic heart disease showed reactivity against the BCKD complex protein, 0 of 30 sera from normal human volunteers, 0 of 64 sera from patients with lupus, and 0 of 34 sera from patients with rheumatoid arthritis showed detectable reactivity, denoting an element of specificity for the reactivity of sera from IDCM patients. The major reactivity was localized to the dihydrolipoyl transacylase (E2) component of BCKD complex. By using recombinant techniques, the immunodominant BCKD-E2 epitope recognized by sera from IDCM patients was localized to amino acid (aa) sequences 116 to 134. Each of the IDCM sera that reacted with the native BCKD complex was shown to react with the immunodominant peptide, as defined by a peptide inhibition ELISA and by an ELISA using the reactive peptide conjugated to BSA. Sera from IDCM patients that reacted with the native BCKD complex and the reactive peptide also showed inhibition of BCKD enzyme activity. The possible mechanisms for the induction of the Abs and the implications of these findings for the pathogenesis of IDCM are discussed.

Epitope mapping of the branched chain alpha-ketoacid dehydrogenase dihydrolipoyl transacylase (BCKD-E2) protein that reacts with sera from patients with idiopathic dilated cardiomyopathy

Sera from 29 of 48 patients with idiopathic dilated cardiomyopathy (IDCM) and six of six patients with dilated cardiomyopathy (DCM) secondary to suspected viral myocarditis were shown to react with the branched chain alpha-ketoacid dehydrogenase (BCKD) complex mitochondrial proteins. Whereas sera from only 1 of 26 patients with ischemic heart disease showed reactivity against the BCKD complex protein, 0 of 30 sera from normal human volunteers, 0 of 64 sera from patients with lupus, and 0 of 34 sera from patients with rheumatoid arthritis showed detectable reactivity, denoting an element of specificity for the reactivity of sera from IDCM patients. The major reactivity was localized to the dihydrolipoyl transacylase (E2) component of BCKD complex. By using recombinant techniques, the immunodominant BCKD-E2 epitope recognized by sera from IDCM patients was localized to amino acid (aa) sequences 116 to 134. Each of the IDCM sera that reacted with the native BCKD complex was shown to react with the immunodominant peptide, as defined by a peptide inhibition ELISA and by an ELISA using the reactive peptide conjugated to BSA. Sera from IDCM patients that reacted with the native BCKD complex and the reactive peptide also showed inhibition of BCKD enzyme activity. The possible mechanisms for the induction of the Abs and the implications of these findings for the pathogenesis of IDCM are discussed.

Comparison of the enzymatic activities of native and recombinant protein phosphatase-1 toward histone

The activities of native and recombinant rabbit muscle protein phosphatase-1 toward phosphorylated lysine-rich histone and phosphorylase a were compared. The activity of rabbit muscle protein phosphatase-1 toward histone is strongly stimulated by Mn++. In the case of the recombinant enzyme, both phosphorylase phosphatase and histone phosphatase activities exhibit a dependence on Mn++. Examination of the activities of both enzymes assayed under optimal conditions show that they exhibit similar substrate specificities toward histone and phosphorylase, contrary to previous claims (Alessi et al., Eur. J. Biochem. 213, 1055-1066, 1993).

The reductive acetyl coenzyme A pathway: sequence and heterologous expression of active methyltetrahydrofolate:corrinoid/iron-sulfur protein methyltransferase from Clostridium thermoaceticum

The methyltransferase (MeTr) from Clostridium thermoaceticum transfers the N5-methyl group of (6S)-methyltetrahydrofolate to the cobalt center of a corrinoid/iron-sulfur protein in the acetyl coenzyme A pathway. MeTr was purified to homogeneity and shown to lack metals. The acsE gene encoding MeTr was sequenced and actively expressed in Escherichia coli at a level of 9% of cell protein. Regions in the sequence of MeTr and the E. coli cobalamin-dependent methionine synthase were found to share significant homology, suggesting that they may represent tetrahydrofolate-binding domains.

Markedly enhanced cytochrome P450 2E1 induction and lipid peroxidation is associated with severe liver injury in fish oil-ethanol-fed rats

We evaluated the role of changes in cytochrome P-450 2E1 (CYP 2E1) and lipid peroxidation in relation to development of severe liver injury in fish oil-ethanol-fed rats. The experimental animals (male Wistar rats) were divided into 5 rats/group and were fed the following diets for 1 month: corn oil and ethanol (CO+E) or corn oil and dextrose (CO+D), and fish oil and ethanol (FO+E) or fish oil and dextrose (FO+D). For each animal, microsomal analysis of CYP 2E1 protein, aniline hydroxylase activity, fatty acid composition, and conjugated dienes was conducted. Also, evaluation of severity of pathology was done for each rat. The mean +/- SD of the pathology score was significantly higher (p < 0.01) in the FO+E (6.0 +/- 1.3) group than in the CO+E group (3.0 +/- 0.5). No pathological changes were evident in the dextrose-fed controls. The CYP 2E1 protein levels (mean +/- SD) were significantly higher (p < 0.01) in the FO+E group (13.1 +/- 2.0) compared with the CO+E (4.7 +/- 1.2) and FO+D (1.8 +/- 0.5) groups. Higher levels of eicosapentaenoic and docosahexaenoic acids and lower levels of arachidonic acid were detected in liver microsomes from rats fed fish oil compared with corn oil. A significant correlation was obtained between CYP 2E1 protein and conjugated diene levels (r = 0.78, p < 0.01). Our results showing markedly increased CYP 2E1 induction and lipid peroxidation in the FO+E group provides one possible explanation for the greater severity of liver injury in this group.

The STL1 gene of Saccharomyces cerevisiae is predicted to encode a sugar transporter-like protein

A gene has been cloned from the yeast Saccharomyces cerevisiae which, on the basis of the deduced translation product, encodes a sugar transporter-like protein. This gene, STL1, was identified as an open reading frame (ORF) closely linked to the cinnamic-acid-resistance gene POF1 on chromosome IV. The putative translation product of STL1 (STL1) contains 536 amino acids, with a M(r) of 60,507. Hydropathy analysis of STL1 suggests that it contains the twelve transmembrane (TM) domains characteristic of a family of sugar transporters from S. cerevisiae and other organisms. STL1 displays greatest homology (28% identity) to the products of the yeast HXT2 (hexose transporter) and GAL2 (galactose transporter) genes. Disruption of STL1 had no detectable effect on yeast growth on glucose, galactose, mannose, maltose or glycerol as sole carbon source. The transport function of the gene product remains unknown at present.

Changes in cytochromes P-450, 2E1, 2B1, and 4A, and phospholipases A and C in the intragastric feeding rat model for alcoholic liver disease: relationship to dietary fats and pathologic liver injury

The influence of dietary fat and alcohol on hepatic microsomal levels of cytochromes P-450 2E1, 2B, and 4A; phospholipases A and C; and UDP-glucuronosyltransferase was studied in the intragastric feeding rat model for alcoholic liver injury. Eight groups of animals were evaluated. Control and ethanol fed rats received either saturated fat or corn oil and were killed after 2 weeks and 1 month of feeding. All animals were pair-fed by continuous infusion of liquid diet through permanently implanted gastric cannulas. Alcoholic liver injury developed only in the corn oil-ethanol-fed groups and was manifest by 1 month. Livers were subjected to the following analyses: pathologic evaluation of liver injury; levels of cytochromes P-450 2E1, 2B, and 4A protein and mRNA; aniline hydroxylase activity; and phospholipase A and C and UDP-glucuronosyltransferase activities. Ethanol-induced increases in cytochromes P-450 2E1 and 2B protein determined by Western blotting were greatest in the corn oil-ethanol-fed group, which developed pathologic changes in the liver. Cytochromes P-450 2E1 and 2B1 mRNA levels were unaffected, suggesting that posttranscriptional mechanisms are responsible for the increase in the corresponding P-450 proteins. In contrast, cytochrome P-450 4A levels were higher in the saturated fat-ethanol groups compared with the corn oil-ethanol groups. Phospholipase A and phospholipase C levels were higher in the corn oil-ethanol groups compared with pair-fed dextrose controls and the saturated fat-ethanol groups. UDP-glucuronosyltransferase levels declined with time in the ethanol-fed groups.(ABSTRACT TRUNCATED AT 250 WORDS)

A device for subjecting vascular endothelial cells to both fluid shear stress and circumferential cyclic stretch

The proposal of the role of mechanical forces as a localizing factor of atherosclerosis has led many researchers to investigate their effects on vascular endothelial cells. Most previous efforts have concentrated on either the fluid shear stress, which results from the flow of blood, or the circumferential "hoop" stretch, which results from the expansion of the artery during the cardiac cycle. In fact, arterial endothelial cells are subjected to both fluid shear stress and cyclic hoop stretch in vivo. Therefore, a more complete investigation of mechanical phenomena on endothelial cell behavior should include both kinds of mechanical stimuli. This study was undertaken to design an experimental apparatus that could subject cultured vascular endothelial cells to simultaneous physiologic levels of both shear stress and cyclic hoop stretch. The experimental apparatus consists of four cylindrical elastic tubes so that the following conditions may be studied: (a) static conditions: (b) shear stress only; (c) hoop stretch only; and (d) shear stress and hoop stretch. In order to establish the functional capabilities of the apparatus, bovine pulmonary artery endothelial cells were cultured in the tubes, and their morphology and f-actin structure were observed with confocal microscopy. The cells remained healthy and attached to the walls throughout the 24 hr experiment. Preliminary results indicated that the alignment of endothelial cells subjected to shear stress was significantly enhanced by the addition of hoop strain.

rDlx, a novel distal-less-like homeoprotein is expressed in developing cartilages and discrete neuronal tissues

From a rat chondrosarcoma we isolated a cDNA that encodes a novel homeoprotein rDlx. The homeodomain of rDlx shows a high degree of sequence identity with those of Drosophila Distal-less, mouse Dlx, and Xenopus Xdll proteins. Northern hybridization of rDlx revealed a 1.4- to 1.6-kb RNA species in a rat chondrosarcoma and a cell line derived from this tumor and in mouse C3H10T1/2 cells, but no rDlx RNA was detected in mouse NIH3T3 fibroblasts, rat skin fibroblasts, mouse C2 myoblasts, mouse myeloma S194 cells, human B-cell lymphoma Daudi cells, or human acute myelocytic leukemia cells. RNase protection assays showed that rDlx transcripts were present at high levels in 14-day-old rat embryos, 18-day-old rat embryo skeletal tissues, and adult rat brain. rDlx RNAs were present at lower levels in newborn rat rib cartilage, 18-day-old rat embryo soft tissues, newborn rat skin, and adult rat heart. rDlx transcripts were not detected in adult rat liver, spleen, lung, kidney, testis, or skeletal muscle. In situ hybridization of rat embryos at different stages revealed that rDlx transcripts were present in otic vesicle, branchial arches, apical ectodermal ridge of limb bud, developing cartilages, perichondria of mature cartilages, mesenchymal cells of developing membranous bones, developing teeth, ganglionic eminence of the telencephalon, diencephalon, olfactory epithelia, and epidermis of the skin. rDlx RNAs were also detected in the developing parasympathetic mesenteric ganglia of the gastrointestinal tract. Hence, rDlx RNAs are mainly expressed in several neuronal tissues and developing skeletal tissues.

A mutant of protein phosphatase-1 that exhibits altered toxin sensitivity

A chimeric mutant was constructed in which a 4-amino acid region (GEFD, residues 274-277) of rabbit muscle protein phosphatase-1 was replaced with the sequence YRCG corresponding to residues 267-270 of rabbit protein phosphatase-2A. This was based on the findings of a gene mutation in okadaic acid-resistant cells which results in a Cys-->Gly conversion in protein phosphatase-2A. The YRCG mutant of protein phosphatase-1 was expressed and purified. The properties of the mutant enzyme were investigated in terms of its sensitivity toward several toxin inhibitors (okadaic acid, microcystin, nodularin, calyculin A, and cantharidic acid), as well as inhibitor-2. The mutant enzyme exhibited a gain of function in the form of a 10-fold increased sensitivity toward okadaic acid that suggests this region is involved in toxin binding. Significant changes in sensitivity to inhibitor-2 and several of the other toxins were also observed, indicating that these may have a common binding region.

[Preliminary investigation on acute flaccid paralysis (AFP) cases in Jinan area]

Eighty AFP cases under 12 years old from 6 hospitals in Jinan were investigated. Among them, there were 17 (21.25%) cases with poliomyelitis (POLIO), 40 (50.00%) cases with Guillian-Barre syndrome (GBS) and 23 (28.75%) cases with other AFP diseases. Most AFP cases occurred from May to October and no significant seasonal difference was found for each kind of AFP cases (P > 0.05), but the average age for POLIO cases (1.55 +/- 1.24) was significantly lower than that for non-POLIO AFP cases (3.76 +/- 2.58) (P < 0.01). The reporting rate from hospitals to each level of epidemic prevention station (EPS) for POLIO, GBS and other AFP cases were 100%, 12.50% and 43.75%, respectively (P < 0.01). Sixty-five AFP cases occurred in 6 prefectures around Jinan city. The average incidence rate (per 100,000) for total AFP, non-POLIO AFP and GBS cases among children under 12 years old were 1.11, 0.89 and 0.53, respectively. The results are helpful to estimate the incidence of AFP cases among children in north provinces of China and also indicate that the POLIO surveillance system in Shandong Province at the present is not sensitive enough, so the AFP cases reporting work of hospitals and the surveillance at each level of EPS should be enhanced.

Use of reverse transcription-polymerase chain reaction to evaluate in vivo cytokine gene expression in rats fed ethanol for long periods

We evaluated the expression of interleukin-1 alpha, interleukin-1 beta, tumor necrosis factor-alpha and transforming growth factor-beta mRNAs in the intragastric-feeding rat model of alcoholic liver disease. Rats were fed different diets for periods of 2 or 4 wk. Animals fed saturated fat and ethanol and the corn oil-dextrose control group had no liver injury, whereas animals fed corn oil and ethanol showed pathologic changes. RNA was extracted from the livers at the time of killing, reverse-transcribed and amplified; polymerase chain reaction products were subjected to electrophoresis on agarose gel. Interleukin-1 alpha mRNA was present in all groups at 2 and 4 wk; interleukin-1 beta and transforming growth factor-beta mRNAs were present in all groups at 4 wk. Tumor necrosis factor-alpha mRNA was absent in all groups at 2 wk but was present in the corn oil-ethanol group only at 4 wk. Because pathological liver injury was evident in the corn oil-ethanol group by 4 wk, the presence of tumor necrosis factor-alpha mRNA at this time suggests a pathogenetic role for tumor necrosis factor-alpha in alcohol-induced liver injury.

Characterization of deletion mutants of the catalytic subunit of protein phosphatase-1

Deletion mutagenesis was used to define the core region of the catalytic subunit of rabbit muscle protein phosphatase-1. Deletions in the N terminus were found to lead to loss of expression. Deletions of up to 33 residues from the C-terminal region were tolerated, and the truncated enzymes were fully active. Deletion of an additional 21 residues led to loss of expression. Mutants which had had 33 and 25 residues deleted maintained specific activities that were comparable to those of the wild type enzyme. The response of these two deletion mutants to okadaic acid, microcystin, and inhibitor-2 was determined. Only slightly lower IC50 values were observed in all cases, showing that the C terminus itself does not play a major role in the binding of these inhibitors. The deletion mutants formed stable complexes with inhibitor-2 as shown by gel filtration. These studies provide unambiguous evidence that the extreme C-terminal region of protein phosphatase-1 is not directly involved in catalytic function or in the binding of inhibitor-2, microcystin, or okadaic acid, and they also establish that the first approximately 300 residues of the sequence constitute a sufficient core for protein phosphatase-1 catalytic functions.