Biomedical subjects

H Li

Publications and source records attributed to H Li.

At least 1,045 records · Page 58Linked to original sources

PubMed1998

Effect of pressure on individual hydrogen bonds in proteins. Basic pancreatic trypsin inhibitor.

By performing two-dimensional 1H NMR measurements at 750 MHz at varying hydrostatic pressure (1-2000 bar) in an aqueous environment (90% 1H2O/10% 2H2O), we found that the signals of the peptide NH protons of basic pancreatic trypsin inhibitor (BPTI) in the folded state shift their positions linearly and reversibly with pressure. The strong tendency for low-field shifts of these protons indicates that most of the amide groups form hydrogen bonds either with carbonyls or with water and that these hydrogen bonds are shortened by pressure. The NH protons interacting favorably with solvent water tend to exhibit larger pressure-induced shifts than others, showing that the shift can be used as a diagnostic probe for the hydrogen bonding state of an NH group with water. Furthermore, we estimated shortening of individual H...O distances of the NH...O=C hydrogen bonds at 2000 bar on the basis of the empirical shift-distance correlation for BPTI. The estimated shortened distances varied considerably from site to site in the range of 0-0.11 A, larger in the turn but smaller in the interiors of secondary structures. These variations suggest that the volume fluctuation is heterogeneous within BPTI and that high-pressure NMR at high field can offer a unique opportunity for detecting microscopic structural fluctuation in proteins.

Aprotinin↗

PubMed1998

Structure of the Vdelta domain of a human gammadelta T-cell antigen receptor.

Antigen recognition by T lymphocytes is mediated by cell-surface glycoproteins known as T-cell antigen receptors (TCRs). These are composed of alpha and beta, or gamma and delta, polypeptide chains with variable (V) and constant (C) regions. In contrast to alphabeta TCRs, which recognize antigen only as peptide fragments bound to molecules of the major histocompatibility complex (MHC), gammadelta TCRs appear to recognize proteins directly, without antigen processing, and to recognize MHC molecules independently of the bound peptide. Moreover, small phosphate-containing non-peptide compounds have also been identified as ligands for certain gammadelta T cells. These studies indicate that antigen recognition by gammadelta TCRs may be fundamentally different from that by alphabeta TCRs. The three-dimensional structures of several alphabeta TCRs and TCR fragments, and their complexes with peptide-MHC or superantigens, have been determined. Here we report the crystal structure of the Vdelta domain of a human gammadelta TCR at 1.9 A resolution. A comparison with antibody and alphabeta TCR V domains reveals that the framework structure of Vdelta more closely resembles that of VH than of Valpha, Vbeta or VL (where H and L refer to heavy and light chains), whereas the relative positions and conformations of its complementarity-determining regions (CDRs) share features of both Valpha and VH. These results provide the first direct evidence that gammadelta TCRs are structurally distinct from alphabeta TCRs and, together with the observation that the CDR3 length distribution of TCR delta chains is similar to that of immunoglobulin heavy chains, are consistent with functional studies suggesting that recognition of certain antigens by gammadelta TCRs may resemble antigen recognition by antibodies.

Amino Acid Sequence↗

PubMed1998

Breast cancer genome anatomy: correlation of morphological changes in breast carcinomas with expression of the novel gene product Di12.

To determine which genes may be activated or inactivated during breast cancer development, we employed two cloning strategies (subtractive hybridization and differential display) using RNA samples from a human breast tumor and its matching normal breast cell line. Of 950 clones isolated, 102 cDNA inserts were analysed by DNA sequencing and database searching. We found 30 clones that were obviously unidentified, with no significant homology to any listed human gene. We focused upon one of the novel genes, Di12, that is differentially expressed as a 1.35 kb RNA in breast cancer tissues and cell-lines, and in several normal tissues. A full length cDNA of this gene was cloned, and its DNA sequence revealed an open reading frame of 339 amino acids. Antibodies to the ten N-terminal amino acids were developed to investigate the expression of Di12 in breast cancer cell-lines and tumors. The Di12 protein was found in tissue sections of infiltrating ductal carcinomas (IDCs), but not in benign or normal breast specimens. RT-PCR analysis confirmed expression of Di12 in 80% of infiltrating ductal carcinomas (IDCs). As IDC constitutes approximately 70% of breast cancers seen clinically, the level of Di12 expression may be predictive of disease progression.

Amino Acid Sequence↗

PubMed1998

4E binding proteins inhibit the translation factor eIF4E without folded structure.

The 4E binding proteins (4E-BP1 and 4E-BP2) inhibit translation by binding to the limiting, proto-oncogenic initiation factor eIF4E. 4E-BPs produced in Escherichia coli had little or no folded structure, measured by NMR and CD. However, these proteins inhibited translation in reticulocyte lysate. Furthermore, they bound to isolated mouse eIF4E, showing a few broader, dispersed new NMR signals but no general increase in chemical shift dispersion. A peptide with the sequence of 4E-BP1 residues 49-68 was sufficient to bind eIF4E and to inhibit translation in reticulocyte lysate. These results suggest that a short central region of the 4E-BPs is responsible for eIF4E binding and translation inhibition while the remainder is unfolded and flexible.

Amino Acid Sequence↗

PubMed1998

Combinations of paclitaxel and vinblastine and their effects on tubulin polymerization and cellular cytotoxicity: characterization of a synergistic schedule.

Paclitaxel (PTX) and vinblastine (VBL) represent 2 classes of drugs that target tubulin but have separate binding properties and opposing mechanisms of action. To evaluate the potential use of these agents together in a chemotherapeutic regimen, we investigated their effects on the dynamics of tubulin polymerization and cellular cytotoxicity, when administered singly or in combination. In human epidermoid carcinoma KB cells and MCF-7 breast carcinoma cells, we observed a time- and dose-dependent effect on cytoskeletal dynamics for both PTX and VBL. Tubulin polymerization induced by PTX was stable for more than 24 hr. When PTX treatment was followed by VBL, a time- and dose-dependent reversal of tubulin polymerization was observed. In contrast, rapid tubulin polymerization occurred when VBL was followed by PTX. When both agents were added simultaneously, a diminution of PTX-induced tubulin polymerization was observed with increasing doses of VBL; a maximum reduction was achieved when equal concentrations were used. Examination of the tubulin pattern by immunofluorescence in MCF-7 breast cancer cells confirmed and extended our findings. Bundle formation followed treatment with PTX. Addition of increasing concentrations of VBL prevented bundling; however, the normal cytoskeletal architecture was not restored. Cytotoxicity studies carried out using the median dose effect principles and the combination index analysis showed synergism when VBL and PTX were administered sequentially and antagonism for simultaneous administration. Our results demonstrate changes in tubulin dynamics following drug treatment and provide a rationale for combined PTX/VBL therapy after careful evaluation of the schedule of administration.

Antineoplastic Agents, Phytogenic↗

PubMed1998

Reinnervation of flaps and grafts of the face.

BACKGROUND: The degree to which disruption of sensory innervation is affected by flaps and grafts on the face has not been explored. The decision to choose a flap or a graft for reconstruction may affect future sensation at the surgical site. OBJECTIVES: To characterize the clinical recovery of sensory innervation after facial reconstructive surgery with flaps and grafts and to offer clinical guidelines on the recovery of sensation in reconstructed sites involving flaps and grafts of the face. METHODS: Seventy patients who underwent Mohs surgery and subsequent repair by either a flap or a graft were evaluated at different postoperative intervals. Fifty patients underwent flap reconstruction and 20 patients underwent graft reconstruction. Three principal modes of sensation were objectively assessed: light touch, temperature, and pinprick. RESULTS: Median time of evaluation after surgery was 11 months. The most common locations tested were the nose (36 patients) and the forehead (9 patients). Postoperative evaluation showed that flap sensation recovery to light touch was present in 10% of patients before 3 months, 41% of patients from 3 to 12 months, 27% of patients from 1 to 2 years, and 75% of patients after 2 years. Graft sensation recovery to light touch was present in no patients evaluated less than 2 years after surgery and in 29% of patients evaluated more than 2 years after surgery. After adjustments for postoperative size and interval, patients with flaps were more likely than those with grafts to have touch sensation at the time of testing (adjusted odds ratio, 8.91; 95% confidence interval, 1.06-74.62; P = .04), to be able to distinguish between warm and cold (adjusted odds ratio, 3.99; 95% confidence interval, 1.05-15.16; P = .04), and to be able to distinguish between sharp and dull (adjusted odds ratio, 27.31; 95% confidence interval, 2.20-339.71; P = .01). CONCLUSIONS: Predictable factors are associated with sensation recovery in patients with flaps and grafts. The recovery of sensory innervation after surgery is earlier with flaps than with grafts. Our data provide clinicians with guidelines for recovery of sensation that ultimately will reassure the patient.

Adult↗

PubMed1998

Semiparametric estimation of major gene effects for age of onset.

Analysis of age of onset is a key factor in the segregation and linkage analysis of some complex genetic traits. Previous work in the genetics literature has used parametric distributional assumptions on age of onset. In this paper, a Cox model with latent major gene effects is used: a semiparametric model with unspecified baseline hazard. A Monte Carlo EM procedure is used to obtain maximum likelihood estimates. Markov chain Monte Carlo is used to realize genotypic configurations from the posterior distribution given the current model and the observed data, and these genotypic configurations are used to estimate the expectations in the EM algorithm. Simulated data sets indicate that the parameters can be estimated well, and one real data set shows the practical applicability of the proposed method.

Age Distribution↗

PubMed1998

Differential requirements for CD28 and CD40 ligand in the induction of experimental autoimmune myasthenia gravis.

The interactions of CD28-B7 and CD40-CD40 ligand (CD40L) pathways in T cell costimulation and autoimmune disease are incompletely understood. We sought to address this issue by investigation of the genesis of acetylcholine receptor (AChR)-induced antibody-mediated experimental autoimmune myasthenia gravis (EAMG) in CD28- and CD40L-deficient mice (CD28-/-, CD40L-/-). Compared to wild-type mice, the CD28-/- mice became less susceptible, and CD40L-/- mice were completely resistant to EAMG induction. Analysis of T helper functions, reflected by cytokine responses, revealed a switch to a Th1 profile in CD28-/- mice. Consistently, levels of serum AChR-specific antibodies of the IgG1 isotype were decreased in CD28-/- mice. In the CD40L-/- mice, both Th1 and Th2 cytokine responses were diminished, and T cell-dependent AChR-reactive B cell responses were more severely impaired than in the CD28-/- mice. Thus, CD28 and CD40L are differentially required for induction of EAMG.

Amino Acid Sequence↗

PubMed1998

Changes in glutathione homeostasis during liver regeneration in the rat.

We have shown previously that plating primary cultures of rat hepatocytes under low density, which stimulates hepatocytes to shift from the G0 to the G1 phase of the cell cycle, resulted in increased levels of glutathione (GSH) and cysteine, and increased activity of gamma-glutamylcysteine synthetase (GCS), the rate-limiting enzyme in GSH synthesis (Lu et al., Am. J. Physiol. 1992;263:C1181-C1189). In the current work we examined changes in GSH homeostasis after two-thirds partial hepatectomy (PH). Male Sprague-Dawley rats underwent two-thirds PH or sham operation. GSH, oxidized glutathione (GSSG), cysteine, GSH efflux, DNA synthesis, changes in GCS subunit messenger RNA (mRNA), and protein levels were measured 12 and 24 hours after PH. Both liver GSH and cysteine levels were doubled at 12 hours and remained elevated at 24 hours after PH. GSSG levels also increased, but the ratio of GSH to GSSG levels remained unchanged. The increase in GSH and cysteine levels preceded the increase in DNA synthesis. Sinusoidal GSH efflux was unchanged after two-thirds PH, but biliary GSH efflux decreased. However, total GSH efflux was minimally altered after two-thirds PH. The increase in GSH can be largely accounted for by the increase in both cysteine availability and the activity of GCS. The steady-state mRNA and protein levels of the GCS heavy subunit were increased at 12 hours after PH. The mRNA level of the GCS light subunit was unchanged. In summary, early in the course of liver regeneration the steady-state hepatic GSH levels double because of an increase in the biosynthesis of GSH.

Animals↗

PubMed1998

The role of quaternary interactions on the stability and activity of ascorbate peroxidase.

Point mutations at the dimer interface of the homodimeric enzyme ascorbate peroxidase (APx) were constructed to assess the role of quaternary interactions in the stability and activity of APx. Analysis of the APx crystal structure shows that Glu112 forms a salt bridge with Lys20 and Arg24 of the opposing subunit near the axis of dyad symmetry between the subunits. Two point mutants, E112A and E112K, were made to determine the effects of a neutral (alanine) and repulsive (lysine) mutation on dimerization, stability, and activity. Gel filtration analysis indicated that the ratio of the monomer to dimer increased as the dimer interface interactions went from attractive to repulsive. Differential scanning calorimetry (DSC) data exhibited a decrease in both the transition temperature (Tm) and enthalpy of unfolding (deltaHc) with Tm = 58.3 +/- 0.5 degrees C, 56.0 +/- 0.8 degrees C, and 53.0 +/- 0.9 degrees C and deltaHc = 245 +/- 29 kcal/mol, 199 +/- 38 kcal/mol, and 170 +/- 25 kcal/mol for wild-type APx, E112A, and E112K, respectively. Similar changes were observed based on thermal melting curves obtained by absorption spectroscopy. No change in enzyme activity was found for the E112A mutant, and only a 25% drop in activity was observed for the E112K mutant which demonstrates that the non-Michaelis Menten kinetics of APx is not due to the APx oligomeric structure. The cryogenic crystal structures of the wild-type and mutant proteins show that mutation induced changes are limited to the dimer interface including an alteration in solvent structure.

Ascorbate Peroxidases↗

PubMed1998

Three-dimensional structure of H-2Dd complexed with an immunodominant peptide from human immunodeficiency virus envelope glycoprotein 120.

The crystal structure of the mouse major histocompatibility complex (MHC) class I molecule H-2Dd with an immunodominant peptide, designated P18-I10 (RGPGRAFVTI), from human immunodeficiency virus envelope glycoprotein 120 was determined at 3.2 A resolution. A novel orientation of the alpha3 domain of Dd relative to the alpha1/alpha2 domains results in significantly fewer contacts between alpha3 and beta2-microglobulin compared with other MHC class I proteins. Four out of ten peptide residues (P2 Gly, P3 Pro, P5 Arg and P10 Ile) are nearly completely buried in the Dd binding groove. This is consistent with previous findings that Dd exploits a four-residue binding motif comprising a glycine at P2, a proline at P3, a positively charged residue at P5, and a C-terminal hydrophobic residue at P9 or P10. The side-chain of P5 Arg is directed toward the floor of the predominantly hydrophobic binding groove where it forms two salt bridges and one hydrogen bond with Dd residue Asp77. The selection of glycine at P2 appears to be due to a narrowing of the B pocket, relative to that of other class I molecules, caused by Arg66 whose side-chain folds down into the binding cleft. Residue P3 Pro of P18-I10 occupies part of pocket D, which in Dd is partially split by a prominent hydrophobic ridge in the floor of the binding groove formed by Trp97 and Trp114. Residues P6 through P9 form a solvent-exposed bulge, with P7 Phe protruding the most from the binding groove and thereby probably constituting a major site of interaction with T cell receptors. A comparison of H-2Dd/P18-I10 with other MHC class I/peptide complexes of known structure provides insights into the possible basis for the specificity of the natural killer cell receptor Ly-49A for several related class I molecules.

Animals↗

PubMed1998

rOmpA is a critical protein for the adhesion of Rickettsia rickettsii to host cells.

rOmpA and rOmpB are immunodominant, surface-exposed proteins of Rickettsia rickettsii. Prior evidence suggests that adhesion of R. rickettsii to the host cell is mediated by a rickettsial protein. Five monoclonal antibodies to rOmpA, five to rOmpB, and one to the rickettsial lipopolysaccharide (LPS) were tested for inhibition of rickettsial attachment. All the monoclonal antibodies to rOmpA inhibited adhesion of rickettsiae to the L-929 cells with some inhibition rates as high as 90%. In contrast, monoclonal antibodies to rOmpB and LPS did not block attachment. When Fab fragments of monoclonal antibodies against rOmpA and rOmpB were used, similar results were observed as for the intact monoclonals, non-adhesion and adhesion, respectively. Purified rOmpA showed a competitive inhibitive effect on the attachment of R. rickettsii to host cells. Trypsin completely digested rOmpA but not rOmpB from the surface of intact R. rickettsii, resulting in loss of the ability of the rickettsiae to attach to the host cell. rOmpA appears to play an important role in the initial adhesion of R. rickettsii to the host cell.

Animals↗

PubMed1998

Sequelae of unrecognized gestational diabetes.

OBJECTIVE: Prior studies have suggested that macrosomia is the only morbid condition associated with gestational diabetes and that this association is the result of confounding by maternal obesity rather than a result of gestational diabetes itself. We sought to determine whether unrecognized gestational diabetes is an independent predictor of macrosomia and other perinatal morbid conditions after controlling for confounding variables. STUDY DESIGN: A retrospective analysis of 472 consecutive cases of gestational diabetes diagnosed between 24 and 30 weeks' gestation was undertaken including 16 prospectively identified but clinically unrecognized cases, 297 cases treated with diet alone, and 76 treated with diet plus insulin. Unrecognized cases were matched to 64 nondiabetic controls for race, age, body mass index, parity, pregnancy weight gain, and gestational age at delivery. RESULTS: In the unrecognized gestational diabetes group versus the nondiabetic control versus gestational diabetes diet groups rates of large for gestational age infants (44% vs 5% vs 9%, p < 0.0005), macrosomia (44% vs 8% vs 15%, p < 0.01), shoulder dystocia (19% vs 3% vs 3%, p < 0.05), and birth trauma (25% vs 0% vs 0.3%, p < 0.001) were all significantly increased. These differences remained significant after controlling for maternal age, race, parity, body mass index, pregnancy weight gain, and gestational age at delivery. CONCLUSIONS: This study suggests that unrecognized gestational diabetes increases risks of large for gestational age infants, macrosomia, shoulder dystocia, and birth trauma independent of maternal obesity and other confounding variables. Clinical recognition and dietary control of gestational diabetes are associated with a reduction in these perinatal morbid conditions.

Adult↗

PubMed1998

Triterpenoid saponins and sapogenins from Vaccaria segetalis.

Four new triterpenoid saponins, vaccarosides E, F, G and H were isolated from the seeds of Vaccaria segatalis and were respectively defined to be 3-O-beta-D-galactopyranosyl(1-->2)-beta-D-glucuronopyranosyl] quillaic acid 28-O-beta-D-xylopyranosyl-(1-->4)-chi-L-rhamnopyranosyl-(1-->2)- [chi-L-arabinofuranosyl-(1-->3)]-beta-D-4-O-acetylfucopyranoside; 3-O-[beta-D-galactopyranosyl-(1-->2)-beta-D-glucuronopyranosyl] 3beta,4chi,16chi-trihydroxy-23-norolean-12-en-28-oic acid 28-O-beta-D-xylopyranosyl-(1-->4)-chi-L-rhamnopyranosyl-(1-->2)- [chi-L-arabinofuranosyl-(1-->3)]-beta-D-4-O-acetylfucopyranoside; 3-O-[beta-D-galactopyranosyl-(1-->2)-beta-D-glucuronopyranosyl] gypsogenin 28-O-beta-D-xylopyranosyl-(1-->4)-chi-L-rhamnopyranosyl-(1-->2)- [chi-L-arabinofuranosyl (1-->3)]-beta-D-4-O-acetylfucopyranoside; and 3-O-[beta-D-galactopyranosyl-(1-->2)-beta-D-glucuronopyranosyl] 3beta,4chi-dihydroxy-23norolean-12-en-28-oic acid 28-O-beta-D-xylopyranosyl-(1-->4)-chi-L-rhamnopyranosyl-(1-->2) -chi-L-arabinofuranosyl-(1-->3)]-beta-D-4-O-acetyfucopyranoside. Their structures were established on the basis of extensive NMR (DEPT, COSY, HOHAHA, HETCOR, HMBC AND NOESY), FAB-MS and ESI-MS studies as well as chemical strategies and enzymatic degradation. The new aglycones of two of the saponins have been designated as segetalic acid and vaccaric acid, respectively.

Carbohydrate Conformation↗

PubMed1998

Long-term mechanical reliability of multicomponent inflatable penile prosthesis: comparison of device survival.

OBJECTIVES: To determine the mechanical reliability of multicomponent inflatable penile prosthesis, comparing five different types of devices, as well as the two-piece versus three-piece as a group. METHODS: We followed 83 patients with two-piece and 283 patients with three-piece inflatable penile prostheses for a mean time of 66 months. At a cutoff of 63 months, mechanical complication rates were reviewed and statistically analyzed. RESULTS: Thirty-one device-related complications occurred, and all were secondary to fluid leakage. The Mentor Alpha-1 prosthesis was significantly better than the Mentor Mark-II in terms of mechanical reliability (P = 0.01). A trend was noted toward the AMS 700 Ultrex inflatable penile prosthesis having fewer mechanical complications than the Mentor Mark-II (P = 0.06). In addition, a trend toward all three-piece prostheses being more mechanically reliable than the two-piece was noted (P = 0.08). The Mentor Alpha-1 device had a higher cumulative proportional survival (0.957) than all other devices (0.842 for AMS 700 Ultrex, 0.839 for AMS 700 CX, 0.783 for Mentor GFS, and 0.750 for Mentor Mark-II). CONCLUSIONS: As a group, a trend was noted toward the three-piece prosthesis having better mechanical reliability than the two-piece prosthesis. Comparisons between the individual types of prostheses showed thatthe Mentor Alpha-1 device was significantly more mechanically reliable than the Mentor Mark-II device, and a trend was noted toward the AMS 700 Ultrex device having fewer mechanical complications than the Mentor Mark-II. The Mentor Alpha-1 prosthesis had the highest cumulative proportional survival.

Adult↗

PubMed1998

Assessment of psychosexual adjustment after insertion of inflatable penile prosthesis.

OBJECTIVES: To evaluate the psychosexual benefit obtained from multicomponent penile implant surgery in patients with erectile dysfunction. METHODS: A psychosexual questionnaire was given to 35 patients undergoing penile prosthesis implantation before surgery and at 3 months, 6 months, and 1 year after surgery. The questionnaire consisted of 13 questions scored on a scale from 1 through 5. Results of the questionnaire were statistically analyzed for differences among the preoperative, 3-month postoperative, 6-month postoperative, and 1-year postoperative period. RESULTS: The general linear model evaluation showed a significant difference for each overall combination of the following pairs: preoperative versus 3 months postoperative (P=0.0005) and 3 months postoperative versus 6 months postoperative (P=0.002). There was no overall difference between psychosexual total score at 6 months after surgery and 1 year after prosthesis implantation (P=0.85). The patients perceived improvement in their erectile ability and libido. Concern about obtaining and maintaining an erection during intercourse was significantly alleviated. There was an increase in the frequency of sexual activity and an improvement in satisfaction with sex life. A decrease in feelings of sadness, depression, anxiety, anger, frustration, and embarrassment related to sexual activity was also noted. CONCLUSIONS: The current study demonstrates significant improvement in the psychosexual well being of multicomponent penile implant recipients, with attainment of a high level of patient satisfaction up to 1 year after surgery.

Adaptation, Psychological↗

PubMed1998

Failure of ibogaine to produce phencyclidine-like discriminative stimulus effects in rats and monkeys.

The discriminative stimulus properties of ibogaine were investigated in rats trained to discriminate phencyclidine (PCP; 2.0 mg/kg, I.P.) from saline under a two-lever fixed-ratio (FR) 32 schedule of food reinforcement. Ibogaine (5.6-17.6 mg/kg, I.P.) showed a complete lack of substitution. Ibogaine (0.5-4.0 mg/kg, I.M.) also failed to generalize in rhesus monkeys trained to discriminate PCP (0.1 mg/kg, I.M.) from sham injection. Lysergic acid diethylamide (LSD), tested as a reference compound, produced partial substitution for PCP in rats and occasioned little responding on the PCP-associated lever in monkeys. These results demonstrate important differences between the behavioral effects of PCP and other types of hallucinogenic drugs such as LSD and ibogaine and do not support the hypothesis that the affinity of ibogaine for the PCP site on N-methyl-D-aspartate (NMDA) receptors plays a major role in its acute behavioral effects.

Animals↗

PubMed1998

Immunoblot analysis of salivary allergens in 10 mosquito species with worldwide distribution and the human IgE responses to these allergens.

BACKGROUND: Most people develop skin reactions to mosquito bites, however, little is known about mosquito salivary allergens and the IgE responses to them. OBJECTIVES: We sought to identify these allergens and the specific IgE responses they elicit. METHODS: Saliva or salivary gland extracts were prepared from 10 mosquito species, including seven species with worldwide distribution: Aedes (Ae.) aegypti, Ae. vexans, Ae. albopictus, Ae. togoi, Ae. triseriatus, Culex (Cx.) quinquefasciatus, Cx. pipiens, Cx. tarsalis, Anopheles (An.) sinensis, and Culiseta (Cs.) inornata. Proteins from these preparations were separated by sodium dodecylsulfate-polyacrylamide gel electrophoresis and transferred to nitrocellulose membranes, which were immunoblotted by sequential incubations with human serum, monoclonal anti-human IgE, and enzyme-conjugated goat anti-mouse IgG. Salivary allergens were analyzed by using a pooled serum from subjects allergic to mosquitos. Individual IgE responses to each allergen were evaluated in 12 subjects allergic to mosquitos living in Canada, the United States, and China, as well as in five subjects not allergic to mosquito bites. To study species-shared allergens, the membranes were immunoblotted with two rabbit antibodies specific to recombinant mosquito salivary proteins. RESULTS: Three to sixteen salivary allergens with molecular masses ranging from 16 to 95 kd were found in each species. Both species-shared and species-specific allergens were identified by molecular masses, binding to the two rabbit antibodies, and individual IgE responses to species indigenous to and absent from the regions where the subjects lived. Salivary allergens, especially from Ae. aegypti, Ae. vexans, and Ae. albopictus, elicited higher IgE responses in subjects allergic to mosquitos than in nonallergic subjects. CONCLUSIONS: Species-shared and species-specific allergens that cause IgE responses in subjects allergic to mosquitos are immunologically identified. Species-shared allergens are the most important for potential use in diagnosis and immunotherapy.

Allergens↗