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At least 793 records · Page 44Linked to original sources
PubMed2000

Characterization of ep prostanoid receptor subtypes in primary cultures of bovine ciliary epithelial cells by immunofluorescent microscopy and functional studies.

PURPOSE: To determine the expression and functional coupling of EP prostanoid receptor subtypes to second messenger pathways in bovine ciliary epithelium. METHODS: Primary cultures of bovine ciliary epithelial (BCE) cells were established and maintained in culture up to four passages. EP receptor protein expression was examined by indirect immunofluorescence microscopy with subtype selective antibodies in both tissue sections and primary cultures of BCE cells. Messenger RNA expression was determined using reverse transcription and polymerase chain reaction. The effects of prostanoid agonists on total inositol phosphate accumulation and cAMP formation were used to assess functional activity. RESULTS: Positive immunoreactivity was obtained in both frozen thin-sections and primary cultures of bovine ciliary process to the prostanoid EP(1 ), EP(2), EP(3) and EP(4) receptor subtypes. Reverse transcription followed by the polymerase chain reaction yielded products corresponding to each of the prostanoid EP subtypes which was confirmed by restriction enzyme analysis. PGE(2) dose-dependently stimulated the accumulation of total inositol phosphates in cultured cells with an EC( 50) value of 100 nM. PGE(2), forskolin and isoproterenol produced dose-dependent increases in cAMP formation with EC(50) values of 100, 300 and 200 nM, respectively. Isoproterenol-stimulated cAMP formation was attenuated by the EP(3) receptor agonist sulprostone in cultured BCE cells. The inhibition elicited by sulprostone was reversed in cells pretreated with pertussis toxin. CONCLUSIONS: This study demonstrates the presence of functional prostanoid EP receptor subtypes in the bovine ciliary epithelium. EP(1) and EP(4) receptor subtypes were found primarily in the NPE cells, whereas, EP(2) receptor subtype immunofluorescence was detected in the PE cells. EP(3) receptor subtype labeling was observed in both the NPE and the PE cells. PGE(2) produces opposing effects on adenylyl cyclase through EP(2)/EP(4) and EP(3) receptor activation. The predominant effect of PGE(2) is on the adenylyl cyclase stimulatory receptors (EP(2)/EP(4)).

Animals↗
PubMedDate not supplied

Emergence of subtype strains of the Arkansas serotype of infectious bronchitis virus in Delmarva broiler chickens.

Infectious bronchitis virus (IBV) field isolates of the Arkansas (Ark) serotype were identified by reverse transcription-polymerase chain reaction (RT-PCR) as the most common serotype isolated from 1993 to 1997. These isolates were recovered from broiler flocks with respiratory disease raised on the Delmarva peninsula in spite of Ark vaccination in the region. For the purposes of investigating this apparently paradoxical finding, five RT-PCR Ark-positive field isolates recovered in 1995 and 1996 were selected for further characterization. The isolates were compared with Ark reference strains by reciprocal virus neutralization (VN) in embryonated eggs, S-1 gene sequence analysis, and challenge of immunity studies in specific-pathogen-free (SPF) chickens. Antigenic (VN) comparisons and S-1 gene analysis confirmed that the five RT-PCR Ark-positive field isolates were of the Ark serotype but also revealed that the viruses could be readily distinguished from Ark reference strains. Four of the isolates (Ark/213/96, Ark/15C/96, Ark/1529/95, Ark/1534/95) were found to have higher antigenic relatedness percentages to each other (95%-100%) than to Ark reference strains DPI (52%-72%) and Georgia variant (Georgia var) (53%-68%) by VN. Another isolate, Ark/1535/95, was found to differ antigenically from the other four RT-PCR Ark-positive field isolates (34%-61%), Ark DPI (44%), and Georgia var (43%) strains. The trends in the S-1 gene sequencing results were similar to those observed for the VN findings. Isolates Ark/213/96, Ark/15C/96, Ark/1529/95, and Ark/1534/95 demonstrated a higher degree of predicted S-1 amino acid similarity to each other (96.5%-98.7%) than to Ark DPI (92.4%-93.7%), Ark 99 (93.2%-94.7%), and Georgia var (89.3%-90.8%). Ark/1535/95 S-1 amino acid similarity values were lower compared with those of the other four RT-PCR Ark-positive field isolates (93.4%-94.8%), Ark DPI (91.9%), Ark 99 (93.0%), and Georgia var (88.7%). Furthermore, the isolates could be distinguished from the Ark reference strains by a characteristic sequence polymorphism, a six-nucleotide deletion encoding amino acids 57 (Asp) and 58 (Asp) in hypervariable region 1 of S-1. On the basis of the VN and sequencing findings, isolates Ark/213/96, Ark/15C/96, Ark/1529/95, and Ark/1534/95 were considered to be a single subtype of the Ark serotype. The fifth isolate, Ark/1535/95, may constitute another subtype of the Ark serotype. Vaccination of SPF chickens with a high-titering commercially available live vaccine containing the Ark DPI strain provided solid protection (>90%) against challenge with the RT-PCR Ark-positive field isolates. Immunization of SPF chickens with Ark/213/96 produced 100% protection against challenge with the homologous strain, as well as isolates Ark/1535/95 and Ark 99 but lower levels of protection against Ark DPI (58%) and Georgia var (55%). Primers for RT-PCR were designed to distinguish between the Ark subtypes and the Ark reference strains on the basis of the characteristic six-nucleotide deletion identified in the S-1 gene of the Ark subtypes. Retrospective analysis of RT-PCR Ark-positive isolates found that the Ark subtypes existed as early as 1992 in Delmarva broilers and became prevalent by 1995. With RT-PCR, restriction fragment length polymorphism analysis, and DNA sequencing techniques, the presence of Ark subtype viruses was demonstrated in two commercial Ark DPI strain vaccines and in our Ark DPI laboratory stocks that were the original source of the virus used for vaccine development. The demonstration of the Ark subtype and reference strains in the Ark DPI strain is evidence of the existence of IBV quasispecies. Factors possibly influencing the emergence of the Ark subtype in commercial broilers are discussed.

Animals↗
PubMed1999

Hepatitis B surface antigen subtypes in hepatitis B seropositive subjects in University Hospital, Kuala Lumpur.

Hepatitis B surface antigen can be serologically defined as ayw1, ayw2, ayw3, ayw4, ayr, adw2, adw4 and adrq+ or adrq-. A study of common HBsAg subtypes in 44 HBsAg reactive sera in University Hospital was conducted using a solid-phase sandwich EIA. Eleven samples were found not typable and among the 33 typable HBsAg reactive sera, 3 HBsAg subtypes: adw, adr and ayw were identified. Subtype adw was found in 66.7% (22/33) of the typable HBsAg reactive sera; 24.2% (8/33) was of subtype adr and 6.0% (2/33) of subtype ayw. One sample was found to be reactive to both adw and adr. HBsAg subtype adw was found more commonly in Chinese but among the Malays, HBsAg subtype adr appeared to predominate. However, the small sample size precludes firm conclusions on the predominant subtype among the Malays.

Adolescent↗
PubMed2000

Pharmacological and molecular characterization of muscarinic receptor subtypes in human esophageal smooth muscle.

Esophageal peristalsis is dependent on activation of muscarinic receptors, but little is known about the roles of specific receptor subtypes in the human esophagus. We examined muscarinic receptor expression and function in human esophageal smooth muscle obtained from patients undergoing resection for cancer. [(3)H]Quinuclidinyl benzylate (QNB)-specific binding was similar in longitudinal muscle (B(max) = 106 +/- 22 fmol/mg of protein, K(d) = 68 +/- 9 pM) and circular muscle (B(max) = 81 +/- 16 fmol/mg of protein, K(d) = 79 +/- 15 pM). Subtype-selective antagonists inhibited [(3)H]QNB similarly in muscle from both layers. Further analysis of antagonist inhibition of [(3)H]QNB binding showed a major site (60-70%) with antagonist affinity profile consistent with the M2 subtype and a second site that could not be classified. Reverse transcription-polymerase chain reaction and immunoblotting demonstrated the presence of all five known muscarinic receptor subtypes, and immunocytochemistry on acutely isolated smooth muscle cells confirmed the expression of each subtype on the muscle cells. Subtype-selective antagonists had similar inhibitory effects on carbachol-evoked contractions in longitudinal muscle and circular muscle strips with pA(2) values of 9.5 +/- 0.1 and 9.6 +/- 0.2 for 4-diphenylacetoxy-N-methylpiperidine methiodide, 7.1 +/- 0.1 and 7.0 +/- 0.2 for pirenzepine, and 6.2 +/- 0.2 and 6.4 +/- 0.2 for methoctramine, respectively. We conclude that human esophageal smooth muscle expresses muscarinic receptor subtypes M1 through M5. The antagonist sensitivity profile for muscle contraction is consistent with activation of the M3 subtype.

Esophagus↗
PubMed2001

Clinicopathological and molecular evidence indicating the independence of bronchioloalveolar components from other subtypes of human peripheral lung adenocarcinoma.

Although human lung adenocarcinoma has diverse histological subtypes, the correlation between histological subtypes and occurrence of the p53 gene mutation has been given less attention. We investigated 145 surgically resected lung adenocarcinomas to search for the incidence of p53 mutations and for record data on survival in each histological subtype, according to the new WHO criteria (1999). The frequency of p53 mutation in bronchioloalveolar carcinoma (BAC; 0% in 17 cases) and BAC with invasive growth component (BAC-invasive; 11% in 27 cases), which is conventionally categorized as the mixed subtype in WHO typing, were apparently significantly lower than in other types (non-BAC including acinar, papillary, solid, or mixed histology with these subtypes; 48% in 101 cases; P < 0.01). Multivariate analysis revealed that the histological subtype including BAC-invasive was a strong, independent, and significant prognostic factor (P < 0.03), as were tumor size and pathological stage (P < 0.001 and 0.002, respectively) for overall survival. However, the occurrence of p53 mutation itself was seen to be significant only in case of the univariate analysis. Therefore, histological subtyping may be a better prognostic indicator than is p53 mutation. These findings suggest that the WHO classification with the BAC and BAC-invasive from other histological subtypes may prove useful to predict the outcome for surgically treated patients with lung adenocarcinoma.

Adenocarcinoma↗
PubMed2001

[Analysis of HIV-1 seropositive individual infected with different subtypes].

OBJECTIVE: To investigate whether there existed any individuals infected with different subtypes of human immunodeficiency virus type 1 (HIV-1) and to analyze their source of infection. METHODS: Membrane protein gene (env) of HIV-1 in uncultured single peripheral blood monocytes (PBMCs) from HIV-1 seropositive individuals found in Shenzhen was amplified by nested polymerase chain reaction (PCR). The C2-V3 region and its adjacent region (360 bp) of them were sequenced and analyzed, and their divergence rate and systematic phylogenetic tree (cladogram) were calculated. RESULTS: There existed sequences of B and C or B and E strains of HIV-1 subtype in three infected individuals in Shenzhen. Gene divergence rates between different subtypes and corresponding international subtype reference strains Bcon, Ccon and Econ were 5.07%-7.26%, 3.23% and 5.38%-5.99%, respectively, and those between different subtypes strains in the same individual were 23.52%, 20.69% and 28.44%, respectively. GPGR sequence of typical Europe and America subtype B was found in strain sz46-1 from prostitute with intravenous drug abuse, based on their tetra-peptide sequence characteristics in the crown of gp 120 V3 loop, strain sz8-2 was GPGH and other strains were GPGQ sequence characterized by Thai B (B') and E subtypes. Furthermore, phylogenetic tree analysis showed that strains sz1-2, sz8-1 and sz46-1 were clustered with international reference sequence Bcon, strain sz1-1 clustered with Econ, and strains sz1-1 and sz8-2 clustered with Ccon. CONCLUSION: These findings suggested that an individual could be simultaneously infected with different HIV-1 subtypes, which could probably be caused by his or her own multiple high-risk behavior.

Adult↗
PubMed2002

Co-existence of HIV-1 subtypes B' and E infections among Thai injecting drug users.

Subtypes B' and E are the two major subtypes of HIV-1 among injecting drug users (IDU) in Thailand. However, there are not many reports on subtype distribution during the early epidemic. Random blood specimens collected during 1994-2000 from 3,286 IDU at the Thanyarak Hospital were tested for HIV antibody and subtyped by using peptide binding enzyme immunoassay. The prevalence rate of HIV infection was 36.8%. All HIV-seropositive IDU were ascertained for "year of first HIV seropositivity" from their medical records. Of 1,512 HIV-seropositive samples, 1,408 (93.1%) were typeable. During 1987-1988, the proportion of subtype B' was as high as 80% but decreased rapidly to 27.6% during 1999-2000. At the same time, the proportions of subtype E increased correspondingly (Chi-square test for the trend, p < 0.05). The relatively high proportion of subtype E among IDU since an early stage of the epidemic suggests early co-existence of both subtypes and needs further investigation.

Adolescent↗
PubMed2001

[Expression of transforming growth factor beta(TGF-beta) subtypes in oral squamous cell carcinoma].

OBJECTIVE: The objective of this study was to determine the expression of transforming growth factor beta (TGF-beta) subtypes and their relationship with the mechanisms of squamous cell carcinoma (OSCC) growth. METHODS: Totally 40 cases of surgical specimens of OSCC resected between 1998 and 2000 and 20 cases of normal human oral mucosa were investigated. Strepto-adridinibiotin complex (SABC) immunohistochemical staining was used to analyze the expression of TGF-beta protein subtypes and their relations with clinical prognosis of OSCC. RESULTS: Semi-quantitative analysis revealed that the subtypes 1, 2 and 3 of TGF-beta protein could be found in OSCC cells and normal oral epithelial cells, however the intensity of protein expression was different. Comparing with those in normal oral mucosa epithelial cells, the subtypes 1 and 2 of TGF-beta were over-expressed in OSCC cells. The over-expression of subtypes 1 and 2 of TGF-beta protein were associated with their pathological grades, clinical stages and neck lymph node metastasis (P < 0.05), whilst the subtype 3 protein of TGF-beta was not. CONCLUSION: It will be useful to detect the expression of TGF-beta subtypes in OSCC, as the subtypes 1 and 2 of TGF-beta may play an important role in OSCC growth and metastasis.

Adult↗
PubMed2003

[Characterization of HIV-1 subtypes in Sfax, Tunisia].

UNLABELLED: We studied HIV-1 subtypes in 20 patients, originating from Tunisia in 18 cases and Libya in 2 other cases and seen in Regional Hospital of Sfax during 1993-1997. Among the 18 tunisian patients, 14 are infected by subtype B. Nine of them are living in european countries and were probably infected by intravenous drug and/or sexual route. The five other patients infected by subtype B correspond to autochtonous cases: 3 patients were infected by their partner, 1 was infected by blood transfusion and the last one has had multiple sexual partners. For another tunisian patient, serum cross-reacted with 2 peptides C and B (C/B) corresponding to coinfection or subtype recombination. Two strains were indeterminate by SSEIA. The last tunisian patient, contaminated in Libya, is infected by a strain presenting cross-reactivity with subtype A and C (A/C). This same strain was found in one libyan patient. The second libyan patient is infected by subtype C. CONCLUSION: In Tunisia, we noted the frequency of HIV-1 subtype B, originating from european countries. But, the fear of other HIV-1 subtypes introduction and therefore, the emergency of new recombinants must incite us to a greatest vigilance in survey of HIV-1 infection.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Polymorphism in HIV-1 non-subtype B protease and reverse transcriptase and its potential impact on drug susceptibility and drug resistance evolution.

HIV-1 non-subtype B viruses are predominant worldwide. At least 9 different HIV-1 group M subtypes and 14 circulating recombinant forms differ from one another by 10-15% in their pol gene, which includes the coding regions for the viral protease and reverse transcriptase (RT), the current targets of antiretroviral drugs. Inter-subtype genotypic diversity includes polymorphism at amino acid residues known to be related to drug resistance in HIV-1 subtype B. Whether polymorphism alters protease and RT function, drug susceptibility, or clinical response to treatment, is unclear. Worldwide dissemination of non-subtype B viruses and increasing availability of antiretroviral drugs in the developing world will expand drug use and the likelihood of drug resistance in non-subtype B viruses. In this review we define and characterize inter-subtype RT and protease polymorphism, and examine the evidence for genotypic and phenotypic differences between HIV-1 subtypes as well as the potential for different clinical responses and evolution of drug resistance among non-B infected individuals.

Anti-HIV Agents↗
PubMed2003

[Identification of B and F human immunodeficiency virus subtypes in Chilean patients].

BACKGROUND: Type I human immunodeficiency virus (HIV) is characterized by a great genetic variability. There are three groups of virus throughout the world: O, N and M. Group M is responsible for AIDS pandemic and is subdivided in 9 genetic subtypes. Most viral strains in South America are subtype B. AIM: To determine the frequency of HIV subtypes in Chilean patients. MATERIAL AND METHODS: Genetic analysis of C2-V3-C3 region of the gene env in HIV strains coming from 77 Chilean subjects infected by different means. DNA heteroduplex mobility assay was used to determine HIV subtypes. RESULTS: Sixty eight cases were infected with subtype B (88.3%) and nine cases were infected with subtype F (11.7%). CONCLUSIONS: Subtype B is the predominant HIV in Chile, but subtype F is also present.

AIDS Serodiagnosis↗
PubMed1992

Selective production of interferon-alpha subtypes by cultured peripheral blood mononuclear cells and lymphoblastoid cell lines.

The biological significance of the existence of multiple interferon-alpha (IFN-alpha) subtypes is unknown but may represent a finely tuned mechanism whereby different subtypes are produced in response to different stimuli. To investigate the expression of individual IFN-alpha subtypes, polyclonal antipeptide antisera designed to react with all IFN-alpha subtypes, or with a particular subtype, IFN-alpha 2 or IFN-alpha 4, have been produced. In this study we demonstrate the utility of these antisera for the detection, using indirect immunofluorescence staining, of intracellular IFN-alpha produced by human peripheral blood mononuclear cells (PBMC) and lymphoblastoid cells. Secreted IFN-alpha was also investigated by bioassay and a sandwich radioimmunoassay (RIA), using two monoclonal antibodies (mAb) and specific for IFN-alpha 4. The PBMC were shown to produce IFN reactive with all three polyclonal antisera, after stimulation with Sendai virus. The lymphoblastoid cells also produced IFN, including IFN-alpha 2, but IFN-alpha 4 was not detected either intracellularly, by immunofluorescence, or in the medium, by sandwich RIA. The immunofluorescence studies also demonstrate that in the absence of viral stimulation IFN-alpha is found in the cytoplasm of PBMC and lymphoblastoid cells but not secreted in detectable levels. The finding that two lymphoblastoid cell lines do not produce the subtype IFN-alpha 4 raises important questions as to whether other cell lines and cell types produce IFN-alpha subtypes selectively, and whether individual IFN-alpha subtypes have different roles in human physiology and pathology.

Biological Assay↗
PubMed1992

[Prognostic relevance of histopathologic subtyping of mixed-cell Hodgkin's disease].

Mixed cellular (MC) type of Hodgkin disease was studied in a group of 92 bioptic cases diagnosed before the start of treatment. A precise histological analysis showed one subtype with lower malignancy (MC 1) and a second one with higher malignancy (MC 2). Subtype MC 1 comprised 61 cases (66 per cent), subtype MC 2 31 cases (34 per cent). Histomorphological subtyping was brought into correlation with clinical data of survival available in 65 cases (44 cases of subtype MC 1,21 cases of subtype MC 2). Different survival in both subtypes had statistical significance and prognostic relevance. Suggested subtyping is simple, based on common histological slides, without need of special additional investigation.

Hodgkin Disease↗
PubMed2006

Comparison of antigenic sites of the envelope glycoprotein of the Iranian isolate of human T-cell leukemia virus type 1 with different subtypes of the virus.

OBJECTIVE: Human T-cell leukemia virus type 1 (HTLV-1) is an enveloped retrovirus, which is associated with a T-cell malignancy known as adult T-cell leukemia (ATL). Variation in the HTLV-1 envelope nucleotide sequence has been extensively documented and has been used to classify HTLV-1 isolates into different subtypes. The virus occurs in at least 3 subtypes, which have been named A, B, and C. We conducted this study to compare the antigenic proprieties of the Iranian isolate of HTLV-1 with the homologous region of different subtypes of the virus. METHODS: This study took place in the Department of Biology, College of Sciences, Shiraz University, Iran in 2005. The predicted antigenic sites and secondary structure of the envelope glycoprotein of HTLV-1, present in Iran, have been compared with the antigenic sites and secondary structure of the homologous domains in subtypes A, B, C of the virus. To predict the epitopes of glycoproteins, 21 different scales were used. RESULTS: The number of helices in the Iranian isolate was equal to the number of these regions in all 3 subtypes, but the number of beta-sheets was more than other viruses. One potential glycosylation site, on all these studied envelope glycoproteins, was predicted. Antigenic sites in the Iranian isolate were almost similar to subtype A of the virus and the Iranian isolate of HTLV-1 may be belongs to subtype A. CONCLUSION: Our results indicate the similarities and differences between the Iranian and other subtypes of HTLV-1. Antigenic sites represent potential candidates for use in a peptide vaccine against HTLV-1 glycoproteins and since most of the properties of a particular protein depend on its structural properties, this type of study can help in better understanding of HTLV-1 isolates present in Iran.

Antibodies, Viral↗
PubMed2006

[Development of a rapid subtype-screening assay for the env region of HIV-1 CRF strains in Guangxi.].

BACKGROUND: To develop a simple and rapid subtype-screening assay for the env region of the circulating recombinant form (CRF) of human immunodeficiency virus type 1 (HIV-1) in Guangxi. METHODS: Proviral DNA from HIV-1 positive samples were extracted and subjected to the first round PCR with universal primers for the env region that can detect HIV-1 M group isolates. In the second round PCR, two pairs of subtype-specific primers that were designed to detect subtype C or B'/C and CRF01-AE respectively were added into one tube. The PCR products of different subtypes could be distinguished in agarose-gel electrophoresis. Additionally, all of these samples were sequenced and analyzed phylogenetically. RESULTS: Phylogenetic analysis of the env region of 50 samples showed that 3 samples (6%) were infected with CRF08-BC, 43 (86%) with CRF01-AE, and 4 (8%) remained unclassifiable. Detection of the subtype-specific primer sets revealed that 3 were subtype C or B'/C (100%), 39 were CRF01-AE (90.7%), with an adequate sensitivity (91.3%) and a high specificity (100%). Non-specific bands occasionally appeared but did not interfere with interpretation of the results. The phylogenetic analysis was consistent with subtype-specific primer sets and the consistency rate was 92%. The average reproducibility was 100% for CRF08-BC samples and 93.8% for CRF01-AE samples. CONCLUSION: A simple, rapid and low cost assay was developed for subtype-screening of CRF01-AE in Guangxi.

China↗
PubMed1991

[Preliminary studies on subtypes of respiratory syncytial virus in China].

An analysis of subtypes of 9 respiratory syncytial (RS) viruses isolated from Guangzhou and Nanjing areas of china was carried out with eight Sweden RS-subtype specific monoclonal antibodies (MAbs) and 7 internal anti-RS MAbs. All these MAbs directed against respectively the large Glycoprotein (G), fusion protein (F), nucleoprotein (NP), and phosphoprotein (P) components of the prototype Long strain of RS virus. The patterns of the reactions of these MAbs to the nine isolated strains of RS virus were compared with indirect immunofluorescence assay (IFA), alkaline phosphoesterase-anti alkaline phosphoesterase (APAAP) enzyme-linked assay and Western blotting. The antigenic variations were founded among the strains of RS virus, and two subtypes allocated to the subtype A and B of RS virus by using the eight RS-subtype specific MAbs. Seven out of the 9 isolated strains of RS virus belonged to the subtype A, and two were being to the subtype B. The antigenic diversities were also founded within the same subtype, and the main pronounced difference were observed on the G glycoprotein by using the internal anti-RS MAbs. These findings are potentially important both for vaccine development and for the understanding of clinical and epidemiological characteristics of RS virus.

Antigenic Variation↗
PubMed1990

[Serotyping and subtyping strains of Neisseria meningitidis isolated from patients in Czechoslovakia 1975-1986].

The paper presents results of serotyping and subtyping of 181 strains of N. meningitidis isolated from patients in the CSR during 1975-1988. A new method of whole-cell ELISA with monoclonal antibodies was used. During the investigation period in strains of N. meningitidis serogroup A only serotype 4 was detected (68.4%) and no subtype was found. In N. meningitidis, serogroups B and C, heterogeneity of serotypes and subtypes was found and a relatively high percentage of strains where the type or subtype could not be detected. In N. meningitidis serogroup B serotype 15 (11.0%) and 4 (8.2%) and subtype P1.15 (14.9%) and P1.2 (12.9%) predominated. In N. meningitidis serogroup C serotype 4 (28.8%) and 15 (7.7%) and subtype P1.2 (21.1%) and P1.6 (11.6%) prevailed. This detected heterogeneity of serotypes and subtypes corresponds to the findings of other authors during non-epidemic conditions. The authors present the most frequent combinations of serotypes and subtypes in strains of different serological groups A : 4 : NT, B : NT : P1.2, B : 4 : P1.15, B : 15 : 1.15, B : 15 : NT, C : 4 : NT, C : NT : P1.2. The work confirms the homogeneity of antigenic properties of N. meningitidis strains isolated from one focus.

Antibodies, Monoclonal↗
PubMed1990

Identification and structural characterization of alpha 1-adrenergic receptor subtypes.

Rat liver and brain membrane alpha 1-adrenergic receptors were purified greater than 500-fold by successive chromatographic steps using heparin-agarose, an affinity matrix constructed by coupling a novel derivative of the alpha 1-selective antagonist prazosin to Affigel-102 and wheat germ agglutinin-agarose. Several lines of evidence were obtained for the existence in brain of an alpha 1-adrenergic receptor subtype that is structurally distinct from that previously characterized in liver and other tissues using photoaffinity labeling, protein purification, and DNA cloning techniques. The alpha 1-selective ligand chlorethylclonidine (CEC) (an alkylating agent) irreversibly inactivates 100% of [3H]prazosin binding sites in partially purified preparations of rat liver. Under identical conditions, only 50% of brain receptors are irreversibly inactivated. Computer modeling of data obtained from the competition by the alpha antagonists WB4101 and phentolamine for [3H]prazosin binding to partially purified preparations of rat liver is best fit by assuming a single class of low affinity sites for both ligands. However, analysis of partially purified brain preparations indicates the presence of two binding sites with different affinities for these antagonists. Additionally, prior alkylation of brain receptors with CEC results in the loss of low affinity phentolamine and WB4101 binding sites. The CEC-insensitive site in brain, which displays high affinity for phentolamine and WB4101, is resistant to photoaffinity labeling by [125I]azidoprazosin. This is not due to a markedly lower affinity of the CEC-insensitive sites for the photoaffinity label, because competition studies with [127I]azidoprazosin revealed a single class of high affinity sites in partially purified brain samples. Photoaffinity labeling of partially purified liver and brain samples not treated with CEC results in the specific labeling of a single protein of Mr 80,000. No specifically labeled protein is observed for partially purified brain samples that had previously been incubated with CEC. Treatment of photoaffinity-labeled liver and brain receptors with N-glycanase to cleave N-linked oligosaccharides results in a single Mr 55,000 protein. Taken together, these data provide evidence for the existence of a single receptor subtype (alpha 1b) in rat liver and for two subtypes (alpha 1a and alpha 1b) in rat brain. Furthermore, the insensitivity of the alpha 1a subtype to CEC and the resistance of the alpha 1a subtype to covalent labeling by an alpha 1b-selective photoaffinity probe suggest that the primary structures of the two receptor subtypes differ, such that an amino acid(s) in the alpha 1b subtype that incorporates CEC and the photoaffinity label is lacking in the alpha 1a subtype.

Affinity Labels↗