Functional epitope analysis of the human CD4 molecule. The MHC class II-dependent activation of resting T cells is inhibited by monoclonal antibodies to CD4 regardless whether or not they recognize epitopes involved in the binding of MHC class II or HIV gp120.

This study was designed to define regions on the human CD4 molecule important for the class II-dependent activation of resting, polyclonal CD4 T cells. With the use of mAb to known epitopes on CD4, we assayed the degree of CD4 saturation and functional effects on T cell activation over a range of antibody concentrations in parallel titration experiments. This approach allows a quantitative comparison of different reagents, regardless of parameters such as affinity for CD4.

Novel anti-CD4 monoclonal antibodies separate human immunodeficiency virus infection and fusion of CD4+ cells from virus binding.

Human immunodeficiency virus (HIV) binds to cells via an interaction between CD4 and the virus envelope glycoprotein, gp120. Previous studies have localized the high affinity binding site for gp120 to the first domain of CD4, and monoclonal antibodies (mAbs) reactive with this region compete with gp120 binding and thereby block virus infectivity and syncytium formation. Despite a detailed understanding of the binding of gp120 to CD4, little is known of subsequent events leading to membrane fusion and virus entry.

Anti-idiotypic antibodies of a predefined specificity generated against CDR3VH synthetic peptides define a private anti-CD4 idiotype.

A synthetic peptide corresponding to the third complementarity determining region (CDR) of the heavy chain (CDR3VH) of anti-Leu3a, a monoclonal anti-CD4 antibody which inhibits HIV gp120 binding to CD4, was used to elicit specific anti-peptide antibodies in rabbits. The anti-peptide antisera showed anti-idiotypic antibody (anti-Id) activity and recognized both the immunizing peptide and the intact cognate protein by ELISA. In addition, the antisera reacted with isolated heavy chains of anti-Leu3a by Western blot analysis.

Enhancement of SIV infection with soluble receptor molecules.

The CD4 receptor on human T cells has been shown to play an integral part in the human immunodeficiency virus type 1 (HIV-1) infection process. Recombinant soluble human CD4 (rCD4) was tested for its ability to inhibit SIVagm, an HIV-like virus that naturally infects African green monkeys, in order to define T cell surface receptors critical for SIVagm infection. The rCD4 was found to enhance SIVagm infection of a human T cell line by as much as 18-fold, whereas HIV-1 infection was blocked by rCD4.

Restriction fragment polymorphism of the cynomolgus monkey major histocompatibility complex.

Among old world monkeys, the major histocompatibility complex (MHC) is defined only in the rhesus (Macaca mulatta), cynomolgus (Macaca fascicularis) and pigtailed (Macaca nemistrina) species. However, little is known about the organization of class I and class II MHC genes or the extent of polymorphism in macaques. In the present study, human and murine class I and class II gene probes were used to analyze the leukocyte antigen (CyLA) system of unrelated and related cynomolgus monkeys.

Overexpression and site-directed mutagenesis of the succinyl-CoA synthetase of Escherichia coli and nucleotide sequence of a gene (g30) that is adjacent to the suc operon.

The succinyl-CoA synthetase of Escherichia coli is encoded by two genes, sucC (beta subunit) and sucD (alpha subunit), which are distal genes in the sucABCD operon. They are expressed from the suc promoter, which also expresses the dehydrogenase and dihydrolipoyl succinyl-transferase subunits of the 2-oxoglutarate dehydrogenase complex. Strategies have now been devised for the site-directed mutagenesis and independent expression of the succinyl-CoA synthetase (alpha 2 beta 2 tetramer) and the individual subunits.

Effectiveness of prophylactic mastectomy in the prevention of breast tumors in C3H mice.

The effectiveness of prophylactic mastectomy in the prevention of breast tumors was studied in spontaneous breast-tumor-forming C3H mice. Prolactin levels were assayed to determine if this hormone was related to the incidence of mammary tumors. Two-hundred and fifty-six 1-month-old C3H mice were divided into four groups (control, 1; sham surgery, 2; mammectomy 50 percent, 3; and mammectomy 100 percent, 4).

Monoclonal antibody Leu-22 (L60) permits the demonstration of some neoplastic T cells in routinely fixed and paraffin-embedded tissue sections.

Monoclonal antibody Leu-22 (L60) detects a T cell-associated antigen which is stably expressed in routinely fixed and paraffin-embedded tissue sections. We investigated the utility of monoclonal antibody Leu-22 to immunophenotype routinely processed lymphoid neoplasms by determining its reactivity in 105 archival pathologic specimens of lymphoid neoplasia that had been previously immunophenotyped by standard cell suspension and frozen tissue section techniques. Monoclonal antibody Leu-22 reacted with 69% of T cell non-Hodgkin's lymphomas (NHLs), including cases belonging to each of the major clinicopathologic categories, and with 22% of B cell NHLs, but did not react with the Reed-Sternberg (RS) cells of Hodgkin's disease (HD).

Interleukin 2 activation of natural killer cells rapidly induces the expression and phosphorylation of the Leu-23 activation antigen.

IL-2 potentiates both growth and cytotoxic function of T lymphocytes and NK cells. Resting peripheral blood NK cells can respond directly to rIL-2, without requirement for accessory cells or cofactors, and enhanced cytotoxicity can be measured within a few hours after exposure to this lymphokine. In this study, we describe an activation antigen, Leu-23, that is rapidly induced and phosphorylated after IL-2 stimulation of NK cells and a subset of low buoyant density T lymphocytes.

Effects of phenylephrine on tissue gas tension, bleeding, infection, and lidocaine absorption.

In an attempt to find a vasoconstrictor with less detrimental local and systemic effects than epinephrine, the effects of phenylephrine, a pure alpha agonist, on tissue gas tension, bleeding, infection rates, and lidocaine absorption were studied. All concentrations of phenylephrine significantly reduced tissue PO2 within 10 minutes of injection, and reduction of PO2 was dose-dependent. Phenylephrine 1:10,000 produced significant bacterial growth when simultaneously injected with 6 X 10(6) Staphylococcus aureus.

Monoclonal antibodies reactive in routinely processed tissue sections of malignant lymphoma, with emphasis on T-cell lymphomas.

The immunoreactivity of eight monoclonal antibodies was evaluated on 45 routinely processed lymphomas (22 T-cell lymphomas, 11 B-cell lymphomas, and 12 cases of Hodgkin's disease). Two antibodies reactive with leukocyte common (T200) antigens (PD7/26 and 2B11) stained most of the B- and T-cell lymphomas but did not stain the Reed-Sternberg cells and variants in Hodgkin's disease. Two antibodies known to stain B cells (LN-1 and LN-2) reacted with some of the B-cell lymphomas, but LN-2 also reacted with the neoplastic cells in six of 22 T-cell lymphomas and with the Reed-Sternberg variants in eight of 12 cases of Hodgkin's disease.

A longitudinal study of nose growth from ages 6 to 18.

The purpose of this study was to investigate nose maturation by cephalometric sagittal surface area methodology longitudinally in males and females. Both males and females exhibited a statistically significant continuum of nose growth from ages 6 to 18. Growth ceased in both sexes at age 18.

Attempts to improve tissue survival during ex vivo storage.

Ex vivo hypothermic perfusion has been shown to enhance short-term survival of organs before transplantation. The effects of perfusion, control of media pH, and systemic drug treatment were studied utilizing superficial epigastric free flaps in Sprague-Dawley rats. Viability of the flaps could be reliably maintained (9/10, 90%) for 72 hours using simple storage in phosphate-buffered Ringer's (pH 7.

Cloning and expression of the succinyl-CoA synthetase genes of Escherichia coli K12.

The genes encoding both subunits of the succinyl-CoA synthetase of Escherichia coli have been identified as distal genes of the suc operon, which also encodes the dehydrogenase (Elo; sucA) and succinyltransferase (E2o; sucB) components of the 2-oxoglutarate dehydrogenase complex. The newly defined genes express polypeptides of 41 kDa (sucC) and 31 kDa (sucD), corresponding to the beta and alpha subunits of succinyl-CoA synthetase, respectively. The genes are thus located at 16.

Brain lesions associated with nonfluent aphasia fifteen years following penetrating head injury.

Men who sustained penetrating head injuries resulting in nonfluent aphasia within six months following injury, were examined fifteen years later and classified into two groups, 13 with persistent nonfluent aphasia, and 26 without symptoms of aphasia. Relative to a normal control group on a comprehensive battery of speech and language tests, the chronic nonfluent aphasics demonstrated syntactic processing deficits in all language modalities, with only mild or no impairment in other language faculties. The recovered group demonstrated deficits only in written expressive syntax.

Hemodynamic alterations secondary to an electrical burn in the rat: a pilot study.

Rats subjected to a standard electrical burn of 250 volts for 10 seconds receive a severe injury stimulating a pronounced systemic circulatory response. Initial postinjury hyperemia is replaced by a low perfusion state within 24 hours. Our study demonstrates the difficulty in isolating regional microcirculatory alterations under such circumstances.

Potentiation of infection by epinephrine.

A subinfective dose of Staphylococcus aureus (6 X 10(6)) does not produce wound infection in the rat model. Reducing the dosage (concentration) of epinephrine results in decreased numbers of viable bacteria in tissue and a lower incidence of wound infection in this model.

Primary structure of the succinyl-CoA synthetase of Escherichia coli.

The primary structure of the succinyl-CoA synthetase of Escherichia coli has been deduced from the nucleotide sequence of a 2451-base-pair segment of DNA containing the corresponding sucC (beta subunit) and sucD (alpha subunit) genes. The genes are located at one end of a gene cluster that encodes several citric acid cycle enzymes: gltA-sdhCDAB-sucABCD; gltA, citrate synthase; sdh, succinate dehydrogenase; sucA and sucB, the dehydrogenase (E1) and succinyltransferase (E2) components of the 2-oxoglutarate dehydrogenase complex. The sucC and sucD genes are separated from the sucA and sucB genes by a 273-base-pair segment containing four palindromic units, but they appear to be expressed from a sucABCD read-through transcript that extends from the suc promoter to a potential rho-independent terminator at the distal end of sucD.

Identical RT1 class II molecules are expressed by rat RT1m and RT1c haplotypes.

The RT1m haplotype of MNR rats has been suggested to be a recombinant RT1 haplotype inheriting RT1.A (class I) alleles from RT1a (DA) and RT1.B (class II) alleles from RT1c (AUG).

Polymorphic class II sequences linked to the rat major histocompatibility complex (RT1) homologous to human DR and DQ sequences.

Until recently, the analysis of Class II genes linked to the rat major histocompatibility complex, RT1, has been confined to serologic and electrophoretic analysis of their gene products. To obtain a more definitive estimate of the number and relative polymorphism of RT1 Class II sequences, we performed Southern blot analysis of rat genomic DNA employing human cDNA probes specific for Class II heavy and light chain genes. Southern blots of EcoRI and BamHI digests of genomic DNA from ten inbred strains, expressing eight RT1 haplotypes, were hybridized with the human DQ beta or DR beta cDNA that are homologous to Class II light chain sequences.

Class I and class II restriction pattern polymorphisms associated with independently derived RT1 haplotypes in inbred rats.

This communication reports the DNA level identification of class I and class II sequences associated with 20 RT1 haplotypes which have been assigned previously to eight RT1 groups. Sixteen to 22 bands in genomic blots hybridized with the mouse pH-2III class I cDNA probe. Only the three RT1k haplotypes associated with identical class I restriction fragment patterns.

Evaluation of sonography in the initial assessment of the gynecologic patient.

Although the importance of sonography in modern obstetrics is undisputed, its role in the evaluation of the patient with gynecologic disease is less clear. We evaluated the role of pelvic sonography in the initial assessment of gynecologic patients. Standardized pelvic sonography was performed on patients scheduled to undergo laparoscopy or celiotomy.