Inhibition by chlorophyllin of 2-amino-3-methylimidazo-[4,5-f]quinoline-induced tumorigenesis in the male F344 rat

This report describes a 1-year carcinogenicity bioassay in which male F344 rats received 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) by gavage 2-3 times per week throughout the first 35 weeks of study, while 0.1% sodium/copper chlorophyllin (CHL) was given concomitantly in the drinking water. The carcinogen dose was calculated to provide an average exposure of 4.2 mg IQ/rat per day, equivalent to that reported in previous carcinogenicity study in which rats were given 0.03% IQ in the diet. Adjusted for length of follow-up, inhibition was highly significant for total tumor burden (P < 0.001), and for specific sites was significant in the small intestine and Zymbal's gland (P < or = 0.1), and in the liver (P < 0.01). In rats given CHL, the first onset of tumors in the Zymbal's gland was delayed from week 20 to 36, but was shortened from week 31 to 26 in the skin (P < 0.05). These results support a chemopreventive role for CHL in several of the major target organs for IQ tumorigenesis in the rat, but raise concerns over possible deleterious effects in the skin.

TDSIR phasing: direct use of phase-invariant distributions in macromolecular crystallography

A new strategy for employing three phase triples invariant estimates from Hauptman's single isomorphous replacement (SIR) and anomalous dispersion (SAS) joint probability distribution formulae is outlined which produces a single unique phase-invariant solution in the case where the positions of the heavy-atom scatterers is known. A similar but non-identical result is obtained for the phase invariants of a structure for which a molecular-replacement solution has been obtained. It is important to note that the values of the individual native/derivative phases can be determined directly from the probability distribution formulae without having to utilize the phase-invariant estimates in an active way. Elimination of the multisolution aspect of utilizing phase-invariant estimates should have important repercussions with regard to phasing macromolecular sets of derivatized data. Trial calculations based on experimentally measured 2.5 A data for three derivatives of cytochrome c550 are encouraging. The average of the three SIR maps resolves a number of structural ambiguities seen in the published multiple isomorphous replacement (MIR) map obtained from eight derivatives.

Prunus necrotic ringspot ilarvirus: nucleotide sequence of RNA3 and the relationship to other ilarviruses based on coat protein comparison

The RNA3 of prunus necrotic ringspot ilarvirus (PNRSV) has been cloned and its entire sequence determined. The RNA3 consists of 1943 nucleotides (nt) and possesses two large open reading frames (ORFs) separated by an intergenic region of 74 nt. The 5' proximal ORF is 855 nt in length and codes for a protein of molecular mass 31.4 kDa which has homologies with the putative movement protein of other members of the Bromoviridae. The 3' proximal ORF of 675 nt is the cistron for the coat protein (CP) and has a predicted molecular mass of 24.9 kDa. The sequence of the 3' non-coding region (NCR) of PNRSV RNA3 showed a high degree of similarity with those of tobacco streak virus (TSV), prune dwarf virus (PDV), apple mosaic virus (ApMV) and also alfalfa mosaic virus (AIMV). In addition it contained potential stem-loop structures with interspersed AUGC motifs characteristic for ilar- and alfamoviruses. This conserved primary and secondary structure in all 3' NCRs may be responsible for the interaction with homologous and heterologous CPs and subsequent activation of genome replication. The CP gene of an ApMV isolate (ApMV-G) of 657 nt has also been cloned and sequenced. Although ApMV and PNRSV have a distant serological relationship, the deduced amino acid sequences of their CPs have an identity of only 51.8%. The N termini of PNRSV and ApMV CPs have in common a zinc-finger motif and the potential to form an amphipathic helix.

Differential regulation of angiotensin II receptor subtypes in rat kidney by low dietary sodium

This study was designed to determine whether expression of renal messenger RNA (mRNA) encoding the two known angiotensin II type 1 (AT1) receptor subtypes (AT1A and AT1B) can be regulated by dietary sodium. Seven-week-old male Wistar rats were fed a low-sodium diet (0.07%, n = 9) or a normal-sodium diet (0.5%, n = 9 [control]) for 14 days. A rat AT1 complementary DNA (cDNA) probe, which hybridizes to mRNA encoding both the AT1A and AT1B receptor subtypes, and cDNA probes, which are selective for AT1A or AT1B mRNA, were used in Northern blot or in situ hybridization analysis. By use of Northern blot analysis, renal mRNA levels for the AT1 and AT1A receptors in rats fed a low-sodium diet were found to be increased twofold (P < .05) compared with control. Because renal AT1B mRNA content was not detected by Northern blot analysis, quantitative image analysis of in situ hybridization with a digoxigenin-labeled cRNA probe made from AT1B cDNA was used. In situ hybridization analysis indicated that AT1B mRNA was expressed in the proximal and collecting tubules of the kidney in rats fed a normal-sodium diet. The low-sodium diet significantly decreased the percent positive staining area of AT1B mRNA in the renal cortex (5.51 +/- 0.77% versus 2.73 +/- 0.35%, P < .05) and medulla (4.76 +/- 0.70% versus 2.01 +/- 0.43%, P < .05) compared with the control diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Vascular endothelial cell growth factor promotes tyrosine phosphorylation of mediators of signal transduction that contain SH2 domains. Association with endothelial cell proliferation

Vascular endothelial cell growth factor (VEGF), an endothelial cell-specific mitogen that plays an important role in angiogenesis, promotes the tyrosine phosphorylation of at least 11 proteins in bovine aortic endothelial cells (BAEC). Proteins immunoprecipitated from lysates of control- and VEGF-stimulated BAEC with antisera to phospholipase C-gamma (PLC-gamma) were fractionated by SDS-polyacrylamide gel electrophoresis and transferred to Immobilon-P. Evaluation of the Western blots with antisera to phosphotyrosine demonstrated that PLC-gamma and two proteins (100 and 85 kDa) that associate with PLC-gamma were phosphorylated in response to VEGF. By using antisera specific to other mediators of signal transduction that contain SH2 domains for immunoprecipitation, it was demonstrated that VEGF promotes phosphorylation of phosphatidylinositol 3-kinase, Ras GTPase activating protein (GAP), and the oncogenic adaptor protein NcK. Proteins of M(r) consistent with the VEGF receptors Flt-1 and Flk-1/KDR were also tyrosine phosphorylated in stimulated cells. Tyrosine-phosphorylated Nck, PLC-gamma, and two GAP-associated proteins, p190 and p62, were in GAP immunoprecipitates of VEGF-stimulated BAEC, and tyrosine-phosphorylated NcK was in phosphatidylinositol 3-kinase immunoprecipitates. These observations suggest that VEGF promotes formation of multimeric aggregates of VEGF receptors with proteins that contain SH2 domains and activate various signaling pathways. VEGF-promoted proliferation of endothelial cells and tyrosine phosphorylation of SH2 domain containing signaling molecules were inhibited by the tyrosine kinase inhibitor genistein.

Creation of a high cytotoxic active human tumor necrosis factor having the truncated and more basic amino terminus

In order to define the structure-functional relationship of tumor necrosis factor(TNF), a mutant TNF gene was created by site-specific mutagenesis based on the PCR technique. This gene was highly expressed in E.coli cells. The amount of the recombinant protein was up to about 80% of the total cellular proteins. Through one-step ion exchange chromatography, the mutant TNF could be purified to homogeneity. This mutein showed the molecular weight of a dimer but not a trimer. It bears the features of truncated amino terminus and increase of the basicity of amino terminal residues. Compared with the wild type TNF, the specific activity of mutant TNF was increased by fourfold.

Identification of a protein with homology to hsp90 that binds the type 1 tumor necrosis factor receptor

The yeast-based two hybrid has been used to identify a novel protein that binds to the intracellular domain of the type 1 receptor for tumor necrosis factor (TNFR-1IC). The TNF receptor-associated protein, TRAP-1, shows strong homology to members of the 90-kDa family of heat shock proteins. After in vitro transcription/translation and 35S labeling, TRAP-1 was precipitated using a fusion protein consisting of glutathione S-transferase and TNFR-1IC, showing that the two proteins directly interact. The ability of deletion mutants of TNFR-1 to interact with TRAP-1 was tested using the two hybrid system. This showed that the amino acid sequences that mediate binding are diffusely distributed outside of the domain in the C terminus of TNFR-1IC that signals cytotoxicity. The 2.4-kilobase TRAP-1 mRNA was variably expressed in skeletal muscle, liver, heart, brain, kidney, pancreas, lung, and placenta. TRAP-1 mRNA was also detected in each of eight different transformed cell lines. Identification of TRAP-1 may be an important step toward defining how TNFR-1, which does not contain protein tyrosine kinase activity, transmits its message to signal transduction pathways.

[Determination of psoralen and isopsoralen in tincture of fructus Psoraleae by HPLC]

A reversed-phase HPLC method was described for the determination of psoralen and isopsoralen in tincture of Fructus Psoraleae. After adding the internal standard and diluting the sample to a definite volume, the sample was injected and analysed. The RSDs were within 2% and the minimum working concentrations below 1 microgram/ml; the average recoveries of psoralen and isopsoralen 102.8% and 99.5% respectively and the linear ranges of psoralen and isopsoralen 12-200 micrograms/ml and 13-210 micrograms/ml (r = 0.999) respectively.

Enroute toward a computer based patient record: the ACIS project

The clinical arm of the University of Utah operates a 400 bed general hospital and 30 specialty and subspecialty clinics and with the advent of managed care will soon be linked to a much wider network of health care facilities throughout the state. Each of these patient care facilities maintains its own patient record. To provide common access to data on any patient needed to provide continuity to the care process where ever it occurs, the institution has embarked on the development of a completely electronic patient record. In this paper we will describe the route we have taken to achieve this goal in hopes of providing some sign posts along the way for others seeking the same destination.

Inhibition of CNS myelin development in vivo by implantation of anti-GalC hybridoma cells

Implantation of hybridoma cells that secrete a monoclonal antigalactocerebroside into the dorsal columns of < or = 9-day-old rat spinal cord results in failure of development of dorsal column myelin in the vicinity of the implant. Clusters of apparently undamaged amyelinated axons remain among the hybridoma cells. Ventral myelin is unaffected. These in vivo results support antibody-mediated inhibition of myelin formation as a potential mechanism underlying failure of remyelination in multiple sclerosis.

Mechanisms of the in vitro antimutagenic action of chlorophyllin against benzo[a]pyrene: studies of enzyme inhibition, molecular complex formation and degradation of the ultimate carcinogen

Mechanisms of the antimutagenic action of chlorophyllin (CHL) towards benzo[a]pyrene (BP) were studied in vitro. In the Salmonella assay, CHL inhibited the mutagenic activity of BP in the presence of an S9 activation system and was particularly effective against the direct-acting ultimate carcinogen, benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE). Spectral studies indicated that the time-dependent hydrolysis of BPDE to tetrols was augmented in the presence of CHL concentrations on the order of 5 microM. Dose-related inhibition of several cytochrome P450-dependent enzyme activities was observed upon addition of CHL to in vitro incubations. Spectral changes for the interaction between CHL and cytochrome P450 indicated that CHL does not bind to the active site of the enzyme, but exerts its inhibitory effect indirectly. This was achieved by inhibiting NADPH-cytochrome P450 reductase (Ki approximately 120 microM with cytochrome c as substrate), and did not involve lowering of the effective substrate concentration by complex formation with the procarcinogen. It is concluded that the in vitro antimutagenic activity of CHL towards BP involves accelerated degradation of the ultimate carcinogen, with inhibition of carcinogen activation occurring only at high CHL concentrations. The latter mechanism is unlikely to occur in vivo following p.o. administration due to the limited uptake of CHL from the gut, but tissue concentrations may be sufficiently high to cause degradation of BPDE.

Effects of cerebellar lesions on tonic seizures, tremor and lifespan in myelin-deficient rats

In common with other dysmyelinating mutants, the myelin-deficient rat displays an action tremor and tonic seizures culminating in the death of the animals at approximately 23-26 days. We find that deep lesions of the cerebellar vermis alleviate the manifestations of the myelin deficiency significantly. Such lesions introduced at 20 days or later eliminate both tremor and seizures for periods up to 10 days. Lifespan is prolonged to nearly 30 days, on average, and to 35 days in some cases. Shallow lesions of the vermis or lateral lobe lesions have relatively little effect. Based on these observations we suggest that the cerebellum contributes not only to the action tremor but also to the tonic seizures characteristic of central myelin deficiency. Spontaneous activity originating in myelin-deficient fiber tracts may be carried to the cerebellum and processed there to produce a highly amplified and/or synchronized output to broad areas of the neuraxis. Deep lesions of the vermis presumably interfere with cerebellar output and compromise the cerebellar contribution to the seizures. Tonic seizures and other 'paroxysmal attacks' also occur commonly in human demyelinating diseases including multiple sclerosis [11]. Manipulation of cerebellar output offers a potential approach to the control of such spontaneous activity.

Inhibition of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ)-DNA binding in rats given chlorophyllin: dose-response and time-course studies in the liver and colon

Chlorophyllin (CHL), a water-soluble salt of chlorophyll, has been shown to inhibit 2-amino-3-methylimidazo[4,5-f]quinoline (IQ)-DNA binding in vitro by a mechanism that involves molecular complex formation with the carcinogen. Based on this mechanism, rats weighing approximately 160 g were given 10 mumol (100 microCi) IQ or IQ plus 20, 200 or 1000 mumol CHL by single oral gavage. Six hours after dosing, CHL produced dose-related inhibition of IQ-DNA binding in three target organs for carcinogenesis, namely, the small intestine, large intestine and liver. In the latter tissues, > 80% inhibition was detected at the highest CHL dose tested, while IQ-DNA binding levels in the small intestine were reduced to below the limit of detection. Co-injection of CHL and IQ into ligated sections of small intestine inhibited the absorption of IQ in a dose-related manner, such that the highest dose of CHL almost completely blocked carcinogen uptake. Finally, rats given CHL by gavage at time 0 h were treated with IQ at various times thereafter and IQ-DNA binding levels were measured in the liver and colon 6 h after carcinogen exposure. Compared with controls given IQ alone, CHL inhibited binding by 79% at 0 h and 40% at 1 h in the liver, and by 63% at 0 h, 38% at 1 h and 58% at 24 h in the colon (P < 0.05 by Student's t-test). These results support a mechanism involving complex formation between CHL and IQ in vivo and suggest that the inhibitor is likely to be most effective when ingested simultaneously with the carcinogen.

Myelin formation by mouse glia in myelin-deficient rats treated with cyclosporine

Previous attempts to generate myelin in the myelin-deficient rat spinal cord by transplanting mouse glia were not successful. In order to determine whether this result was due to graft rejection or to interspecies mismatch of cellular or molecular components at the axoglial junction, we have repeated the experiment in cyclosporine-treated rats. Our results show that in the immunosuppressed hosts, foetal glial xenografts form an abundance of myelin within the dorsal columns at or near the injection site about two weeks after the operation. In some cases, myelination extends virtually across the entire width of the dorsal columns. Ultrastructurally, the myelin sheaths are normal in all respects, including the presence of the 'radial component'. The lateral edges of the myelin lamellae form typical paranodal axoglial junctions, some displaying periodic 'transverse bands'. We infer that previous mouse to rat xenograft failures reflect host immune response rather than mismatch of heterologous junctional components. We also compared foetal, early post-natal and adult xenografts. Foetal donor cells, containing an abundance of precursors but virtually no mature oligodendrocytes, are more effective than neonatal donor cells in forming myelin, and after adult grafts, we found no myelin formation. Thus, in xenografts, as in allografts, foetal precursor cells are far more suitable than glia from mature donors in generating significant amounts of myelin.

DNA sequence-selective binding of head-to-tail linked bis-lexitropsins: relation of phasing to cytotoxic potency

A series of polymethylene, -(CH2)n-tether-linked head-to-tail bislexitropsins (n = 1-7) have been synthesized in order to assess the effect on DNA binding of phasing, that arises because of lack of dimensional correspondence between oligopeptides and oligonucleotides. Binding constants to poly(dA-dT), estimated from ethidium displacement, are from 0.55 to 16.66 x 10(8) M-1. Comparable Ka values for calf thymus DNA and for poly(dG-dC) are approximately 10(6) and approximately 10(5) M-1, respectively reflecting the anticipated AT preference. Sequence-selective binding was examined by reflecting the anticipated AT preference. Sequence-selective binding was examined by methylethidium propyl ethylenediamine tetraacetic acid (MPE) complementary strand footprinting on an EcoRI/HindIII restriction fragment of pBR322 DNA with r = 0.08 and 0.32. Ligands bearing N-methylpyrrole dipeptide moieties linked by -(CH2)n, where n = 2, 4 or 6, give evidence of bidentate binding in (AT)n-rich sequences from footprinting at r = 0.32. By contrast, those ligands linked by (CH2)n, where n = 1, 3, 5 or 7, bind in a predominantly monodentate fashion. Cystostatic activity against KB human nasopharyngeal cancer cells has shown enhanced potency, compared with distamycin, for those linked bis-lexitropsins with n = 2, 4 and 6. That the increased potency may be attributed to more effective DNA binding in the latter cases is indicated by the fact that the n = 1, 3, 5 and 7 ligand homologues do not exhibit comparable enhanced cytotoxic potency.

[An investigation of medicinal Rhodiola in Sichuan Province]

Twenty-two species of Rhodiola produced in Sichuan Province are reported in this paper, including their distributions, habitats and localities. Among them, there is a new species named Rhodiola wolongensis. Its morphology has been described in Latin. I key for the identification of all these 22 species has been compiled and presented.

Persistent vegetative state--clinical and electrophysiologic observations of 5 cases

Five patients who met the criteria of the persistent vegetative state (PVS), were studied for ten years. Among them, two had fallen into a deep coma after cardiopulmonary resuscitation, and the other three cases were due to cerebrovascular disorders. Four patients died within 10 years. Clinically, all five cases showed characteristic features of wakefulness without cognitive function and movement of the extremities. The brain stem reflexes, such as light reflexes of the pupils and corneal reflexes, were present. The electroencephalograms showed ample low amplitude and nonspecific slow waves. None revealed an isoelectric pattern. Brain stem auditory evoked potential (BAEP) studies were normal or slightly abnormal. Median nerve somatosensory evoked potential (SSEP) studies showed absence of a cortical response. These features suggest that the damage in PVS patients is mainly located in the cerebral cortex. Although electrophysiologic examinations are useful diagnostic procedures for PVS, clinical observation remains the basis of the diagnosis.

Antimutagenic potency of chlorophyllin in the Salmonella assay and its correlation with binding constants of mutagen-inhibitor complexes

Chlorophyllin (CHL) is a water-soluble salt of chlorophyll that exhibits antimutagenic activity in short-term genotoxicity assays and inhibits carcinogen-DNA binding in vivo. The antimutagenic potency of CHL was studied against several structurally related heterocyclic amines using the Salmonella assay. The mutagens included 2-amino-3-methylimidazo[4,5,-f]-quinoline (IQ) and seven related IQ-type compounds, and 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) and three additional non-IQ-type compounds. No relationship was observed between mutagenic potency (revertants/ng mutagen) and antimutagenic potency when expressed in terms of the CHL dose/plate-inhibiting mutagenicity by 50 percent (I50). However, a correlation was observed between mutagenic potency and the mole ratio of CHL to mutagen giving 50% inhibition (MR50), with most mutagens requiring several hundredfold to several thousandfold molar excess of CHL for inhibition. In spectrophotometric studies, CHL formed noncovalent molecular complexes with the heterocyclic amines, with binding constants in the range 3-13 x 10(3) M-1. Binding constants were inversely correlated with I50 and MR50 values, i.e., with increasing strength of complex formation less CHL/plate and a lower mole ratio of CHL to mutagen was required to inhibit mutagenicity. The results support an inhibitory mechanism in which chlorophylls operate as "interceptor molecules," interacting with carcinogens and mutagens directly and limiting their bioavailability.

[Textual study of Chinese drug loulu]

Through a critical study of Loulu in ancient Chinese herbals, it is concluded that the botanical origin of Loulu should be Qizhou Loulu, the dried root of Rhaponticum uniflorum of family Compositae, while the dried root of Echinops latifolius, which is also one of the species specified in Chinese Pharmacopoeia, should not be used as Loulu because of its deficiency of herbal evidences and totally different chemical constituents from those of the former. It is therefore recommended the latter plant be deleted from the Chinese Pharmacopoeia.

Inhibition of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ)-DNA binding by chlorophyllin: studies of enzyme inhibition and molecular complex formation

Chlorophyllin (CHL), a copper/sodium salt of chlorophyll used in the treatment of geriatric patients, is an anti-mutagen that has been demonstrated to inhibit carcinogen--DNA binding in vivo. To study the mechanism of inhibition, the microsomal metabolism of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) and the kinetics of IQ--DNA binding were investigated in the presence and absence of CHL. In time-course studies, CHL produced greater than 80% inhibition of IQ--DNA binding and blocked the metabolism of IQ, such that 80% of the initial dose of carcinogen was recovered unmetabolized from the incubations after 1 h. Kinetic constants were determined for the in vitro DNA binding reaction, with the reaction rate measured as 'pmol IQ bound/mg DNA/min/mg microsomal protein'. Without altering V(max), the Km of the IQ--DNA binding reaction was increased by CHL, and the replot of Km/V(max) versus CHL concentration yielded a straight line with an inhibitor constant of 58.3 microM CHL. Spectrophotometric studies provided evidence in vitro for the formation of a non-covalent complex between CHL and IQ. The CHL--IQ complex had a stoichiometric ratio of 2:1 (mole ratio method) and an apparent dissociation constant from the Benesi-Hilderbrand plot of 1.41 x 10(-4)M at pH 7.4. These results are discussed in the context of a CHL inhibitory mechanism involving enzyme inhibition and molecular complex formation.

The adverse effect of marginally higher lead level on intelligence development of children: a Shanghai study

We surveyed 128 preschool children in a lead-polluted area in Shanghai to study the relationship between blood lead level and neuropsychological functions, assessed by age-appropriate psychological tests. The geometric means of blood lead level was 21.7 + -10.8 micrograms/dl. Of 47 children aged below 30 months, there was no significant difference in BSID indices between the high and low lead subjects, although the high lead children tended to have poorer development scores than the low lead ones. On the other hand, of 81 children older than 46 months, the WPPSI IQ scores showed highly significant negative correlation with blood lead level. Step-wise regression and multiple analysis of covariance techniques were employed to find out and control the confounding factors. Even when 21 non-lead variables were considered, the IQ difference between high and low lead groups remained statistically significant. We concluded that the children, especially those older than 46 months, in the area investigated, did suffer from lead toxicity causing impairment in intelligence development. We support the view that marginally higher lead level in children should be taken seriously.

Comparison of different information content models by using two strategies: development of the best information algorithm for Iliad

Iliad is a diagnostic expert system for internal medicine. Iliad's "best information" mode is used to determine the most cost-effective findings to pursue next at any stage of a work-up. The "best information" algorithm combines an information content calculation together with a cost factor. The calculations then provide a rank-ordering of the alternative patient findings according to cost-effectiveness. The authors evaluated five information content models under two different strategies. The first, the single-frame strategy, considers findings only within the context of each individual disease frame. The second, the across-frame strategy, considers the information that a single finding could provide across several diseases. The study found that (1) a version of Shannon's information model performed the best under both strategies---this finding confirms the result of a previous independent study, (2) the across-frame strategy was preferred over the single-frame strategy.

Exploring a new best information algorithm for Iliad

Iliad is a diagnostic expert system for internal medicine. One important feature that Iliad offers is the ability to analyze a particular patient case and to determine the most cost-effective method for pursuing the work-up. Iliad's current "best information" algorithm has not been previously validated and compared to other potential algorithms. Therefore, this paper presents a comparison of four new algorithms to the current algorithm. The basis for this comparison was eighteen "vignette" cases derived from real patient cases from the University of Utah Medical Center. The results indicated that the current algorithm can be significantly improved. More promising algorithms are suggested for future investigation.

New hydrophilicity scale derived from high-performance liquid chromatography peptide retention data: correlation of predicted surface residues with antigenicity and X-ray-derived accessible sites

A new set of hydrophilicity high-performance liquid chromatography (HPLC) parameters is presented. These parameters were derived from the retention times of 20 model synthetic peptides, Ac-Gly-X-X-(Leu)3-(Lys)2-amide, where X was substituted with the 20 amino acids found in proteins. Since hydrophilicity parameters have been used extensively in algorithms to predict which amino acid residues are antigenic, we have compared the profiles generated by our new set of hydrophilic HPLC parameters on the same scale as nine other sets of parameters. Generally, it was found that the HPLC parameters obtained in this study correlated best with antigenicity. In addition, it was shown that a combination of the three best parameters for predicting antigenicity further improved the predictions. These predicted surface sites or, in other words, the hydrophilic, accessible, or mobile regions were then correlated to the known antigenic sites from immunological studies and accessible sites determined by X-ray crystallographic data for several proteins.