Commonly missed orthopedic problems

Orthopedic problems that are often "missed" when the patient presents to the Emergency Department are discussed. Treatment suggestions for these conditions are made.

Crystallization and preliminary crystallographic analysis of a novel nuclease from Serratia marcescens

Crystals have been obtained of the extracellular endonuclease from the bacterial pathogen Serratia marcescens. This magnesium-dependent enzyme is equally active against single and double-stranded DNA, as well as RNA, without any apparent base preference. The Serratia nuclease is not homologous with staphylococcal nuclease, the only other broad specificity endonuclease for which a structure exists, nor is it homologous with other nucleases that have been solved by X-ray diffraction. The structure of this enzyme should, therefore, provide new information about this class of enzyme. At present we have succeeded in obtaining large, high quality crystals using ammonium sulfate. They crystallize in the orthorhombic space group P2(1)2(1)2(1), with cell dimensions a = 106.7 A, b = 74.5 A, c = 68.9 A, and diffract to beyond 2 A. Low-resolution native data sets have been recorded and a search is under way for heavy-atom derivatives.

An activated CD8+ lymphocyte appears in lymph nodes of rhesus monkeys early after infection with simian immunodeficiency virus

Although alterations in T lymphocyte subset distribution and function in the peripheral blood of HIV-infected humans are well defined, the extent to which these reflect changes in other lymphoid compartments is unclear. We have characterized the coincident changes in PBL and lymph nodes (LN)1 after simian immunodeficiency virus of macaques (SIVmac) infection of rhesus monkeys. Whereas no consistent change in CD8+ PBL was noted during the first 60 d after infection, CD8+ lymphocytes increased significantly in number in LN. These CD8+ LN lymphocytes exhibited an increased expression of MHC class II and a decreased expression of leukocyte adhesion molecule-1, suggesting that they were activated, but interestingly did not express CD25 (IL-2 receptor). Moreover, there was no evidence that these CD8+ LN cells were proliferating, suggesting that they had migrated to the LN. These changes in the LN CD8+ lymphocyte population preceded any detectable change in the light microscopic appearance of the LN. When SIVmac-specific effector T cell responses were assessed, the magnitude of virus-specific effector activity was nearly identical in the PBL and LN of each monkey studied. However, the presence of SIVmac-specific effector cells in the LN did not correlate with the presence of CD8+, MHC class II+ cells. These findings suggest that this numerically important CD8+ lymphocyte subpopulation may serve a regulatory function.

Longitudinal analysis of nortriptyline side effects in elderly depressed patients

Forty-five depressed elderly patients were closely monitored in a research setting during treatment with nortriptyline and interpersonal psychotherapy for 7 consecutive months of acute and continuation treatment. Overall, nortriptyline was efficacious and well tolerated in this group. The frequency of somatic complaints measured by the Rating Scale for Side Effects declined by 50% during the acute phase of treatment, suggesting that many somatic complaints that may be attributed to side effects of nortriptyline are actually somatic symptoms of depression. The authors discuss the implications of these findings and offer practical advice for the treating clinician.

Definition of an epitope and MHC class I molecule recognized by gag-specific cytotoxic T lymphocytes in SIVmac-infected rhesus monkeys

Infection of macaque monkeys with the simian immunodeficiency virus of macaques (SIVmac) results in disease similar to human AIDS. Therefore, the macaque monkey is proving to be an important model for testing the effectiveness of various AIDS vaccine approaches. A detailed analysis of the cellular immune responses is necessary for the evaluation of candidate vaccines. However, this has not been possible in macaques, due, in part, to the unknown nature of the MHC molecules that restrict their T lymphocytes. In our report we demonstrate that a particular MHC class I molecule involved in the rhesus monkey's effector T lymphocyte response to SIVmac is expressed at a high frequency in a colony of rhesus monkeys. SIVmac-infected monkeys that express this MHC class I molecule all develop CTL that are restricted by that molecule and recognize an identical nine amino acid epitope of the SIVmac gag protein. This MHC class I molecule has been defined as an HLA-A homolog by cDNA cloning and sequencing. It has also been expressed in an MHC class I-deficient cell line to demonstrate directly the cloned molecule's capacity to bind and present peptide Ag to CTL. These studies illustrate that AIDS virus-specific CTL can be characterized in detail in the rhesus monkey and lay the foundation for exploring novel approaches to AIDS virus vaccination in this species.

Definition of an epitope and MHC class I molecule recognized by gag-specific cytotoxic T lymphocytes in SIVmac-infected rhesus monkeys

Infection of macaque monkeys with the simian immunodeficiency virus of macaques (SIVmac) results in disease similar to human AIDS. Therefore, the macaque monkey is proving to be an important model for testing the effectiveness of various AIDS vaccine approaches. A detailed analysis of the cellular immune responses is necessary for the evaluation of candidate vaccines. However, this has not been possible in macaques, due, in part, to the unknown nature of the MHC molecules that restrict their T lymphocytes. In our report we demonstrate that a particular MHC class I molecule involved in the rhesus monkey's effector T lymphocyte response to SIVmac is expressed at a high frequency in a colony of rhesus monkeys. SIVmac-infected monkeys that express this MHC class I molecule all develop CTL that are restricted by that molecule and recognize an identical nine amino acid epitope of the SIVmac gag protein. This MHC class I molecule has been defined as an HLA-A homolog by cDNA cloning and sequencing. It has also been expressed in an MHC class I-deficient cell line to demonstrate directly the cloned molecule's capacity to bind and present peptide Ag to CTL. These studies illustrate that AIDS virus-specific CTL can be characterized in detail in the rhesus monkey and lay the foundation for exploring novel approaches to AIDS virus vaccination in this species.

Recombinant virus vaccine-induced SIV-specific CD8+ cytotoxic T lymphocytes

Evidence indicates that cytotoxic T lymphocytes (CTLs) may be important in containing the spread of the human immunodeficiency virus (HIV) in the infected host. Although the use of recombinant viruses has been proposed as an approach to elicit protective immunity against HIV, the ability of recombinant viral constructs to elicit CD8+ CTL responses in higher primates has never been demonstrated. A live recombinant virus, vaccinia-simian immunodeficiency virus of macaques (SIVmac), was used to determine whether such a genetically restricted, T lymphocyte-mediated antiviral response could be generated in a primate. Vaccinia-SIVmac vaccination elicited an SIVmac Gag-specific, CD8+ CTL response in rhesus monkeys. These CTLs recognized a peptide fragment that spans residues 171 to 195 of the Gag protein. The rhesus monkey major histocompatibility complex (MHC) class I gene product restricting this CTL response was defined. Both the vaccinated and SIVmac-infected monkeys that shared this MHC class I gene product developed CTLs with the same Gag epitope specificity. These findings support the use of recombinant virus vaccines for the prevention of HIV infections in humans.

Two distinct lymphocyte populations mediate simian immunodeficiency virus envelope-specific target cell lysis

The relative contributions of the effector lymphocyte responses to the AIDS virus envelope glycoprotein (env) were explored in simian immunodeficiency virus of macaques (SIVmac)-infected rhesus monkeys. CD8+, MHC class I-restricted, env-specific CTL were cloned from PBL of SIVmac-infected monkeys, indicating that such cells constitute a component of the env-specific effector lymphocyte response. A limiting dilution 51Cr release assay was then established for quantitating the frequency of SIVmac-specific effector lymphocytes in PBL of rhesus monkeys. Using this assay we demonstrate that SIVmac env-specific effector lymphocytes are comprised of both CD16-, MHC class I-restricted and CD16+, MHC class I-unrestricted cells. We also demonstrate that the env-specific response is the predominant SIVmac-specific effector lymphocyte response in rhesus monkeys. These studies document the complexity of the effector lymphocyte response to the AIDS virus envelope glycoprotein and establish the role played by two distinct effector cell populations in this response.

Two distinct lymphocyte populations mediate simian immunodeficiency virus envelope-specific target cell lysis

The relative contributions of the effector lymphocyte responses to the AIDS virus envelope glycoprotein (env) were explored in simian immunodeficiency virus of macaques (SIVmac)-infected rhesus monkeys. CD8+, MHC class I-restricted, env-specific CTL were cloned from PBL of SIVmac-infected monkeys, indicating that such cells constitute a component of the env-specific effector lymphocyte response. A limiting dilution 51Cr release assay was then established for quantitating the frequency of SIVmac-specific effector lymphocytes in PBL of rhesus monkeys. Using this assay we demonstrate that SIVmac env-specific effector lymphocytes are comprised of both CD16-, MHC class I-restricted and CD16+, MHC class I-unrestricted cells. We also demonstrate that the env-specific response is the predominant SIVmac-specific effector lymphocyte response in rhesus monkeys. These studies document the complexity of the effector lymphocyte response to the AIDS virus envelope glycoprotein and establish the role played by two distinct effector cell populations in this response.

Sequence and chromosomal location of the I-309 gene. Relationship to genes encoding a family of inflammatory cytokines

We previously reported the isolation and characterization of a cDNA clone, I-309, that encodes a small secreted protein produced by activated human T lymphocytes. This protein is structurally related to a large number of recently identified proteins that are secreted upon cellular activation. In this report we describe the isolation and characterization of the gene encoding I-309. The genomic organization is essentially identical to that found in the genes encoding the structurally similar proteins TCA-3, hJE/MCP-1, and mJE, strengthening the hypothesis that these genes are evolutionarily related. The region of the I-309 gene 5' of the mRNA cap site exhibits extensive nucleotide sequence homology with the same region of the murine gene TCA-3, providing additional evidence that I-309 and TCA-3 are likely to be homologs. Finally, panels of rodent-human somatic cell hybrids were used to map the I-309 gene to human chromosome 17. In conjunction with recent mapping data from other laboratories, this result suggests the presence of a cluster of related genes on this chromosome.

Sequence and chromosomal location of the I-309 gene. Relationship to genes encoding a family of inflammatory cytokines

We previously reported the isolation and characterization of a cDNA clone, I-309, that encodes a small secreted protein produced by activated human T lymphocytes. This protein is structurally related to a large number of recently identified proteins that are secreted upon cellular activation. In this report we describe the isolation and characterization of the gene encoding I-309. The genomic organization is essentially identical to that found in the genes encoding the structurally similar proteins TCA-3, hJE/MCP-1, and mJE, strengthening the hypothesis that these genes are evolutionarily related. The region of the I-309 gene 5' of the mRNA cap site exhibits extensive nucleotide sequence homology with the same region of the murine gene TCA-3, providing additional evidence that I-309 and TCA-3 are likely to be homologs. Finally, panels of rodent-human somatic cell hybrids were used to map the I-309 gene to human chromosome 17. In conjunction with recent mapping data from other laboratories, this result suggests the presence of a cluster of related genes on this chromosome.

Developing a model for the study of quality of life in elderly patients with chronic disease: use of hypertension as an example

The concept of quality of life (QOL) is multidimensional and complex, especially in regard to chronic disease and old age. The purpose of this study was to explore QOL in a population of elderly patients with hypertension and to suggest a technique for model building. The specific purpose of the study was to test the viability of a model for understanding how the treatment of hypertension affects QOL. Indicators of QOL and determinants of QOL were measured in a group of patients aged 60 years or older with hypertension. Correlation coefficients confirmed the hypothesized model. The confirmed model thus can be used to study other chronic diseases and to assess the QOL effects of treatment of chronic diseases.

Biochemical and behavioral evidence for muscarinic autoreceptors in the CNS

Muscarinic autoreceptors of the M2 subclass were examined in rat forebrain using a number of different methodologies, including receptor autoradiography and image analysis, regulation of acetylcholine release, phosphoinositide turnover, low-Km GTP hydrolysis, and behavioral analysis. The relatively minor population of M2 receptors in coronal sections was visualized by autoradiography and image analysis using [3H]quinuclidinyl benzilate in the presence of a concentration of pirenzepine that blocked most of M1 (and M4) receptors. The highest densities of M2 receptors in forebrain regions were found in the outer layers of the cortex, CA1 region of the hippocampus and striatum. The M2-, but not M1-selective antagonists were able to block the oxotremorine-induced attenuation of acetylcholine release in forebrain synaptosomes. Low concentrations of the M2-selective antagonist gallamine increased phosphoinositide turnover, which is thought to be an M1 postsynaptic response in the forebrain, in brain slices by a Ca2(+)-dependent mechanism. The M2-selective agonist oxotremorine produced a substantial stimulation of low-Km GTPase in cortical membranes, suggesting that M2 forebrain receptors are efficiently coupled to G-proteins in the cortex. Behavioral signs of cholinergic stimulation were observed after intracerebroventricular injections of M2-, but not M1-selective antagonists. It is suggested that a minor population of forebrain M2 receptors regulates acetylcholine release by a mechanism that includes coupling through G-proteins presynaptically at synapses for which the postsynaptic response involves phosphoinositide turnover. Selective blockade of these receptors produces both biochemical and behavioral signs of acetylcholine release.

Orthopedic trauma in the elderly

The bones of elderly individuals fracture easily. The fractures in osteoporotic bones may not be easily identified on plain films. A high level of suspicion will result in more accurate diagnosis and appropriate referral and treatment of these patients.

Quantitative evaluation of the stability and delivery of interleukin-1B by infusion

The stability and delivery of IL-1 beta has been characterized in a polypropylene based syringe pump infusion system and in polyvinyl chloride based infusion bags, at concentrations ranging from 100 ng/mL to 1 microgram/mL. At higher concentrations (1 microgram/mL), minimal drug loss was observed in both systems. At low doses (100 ng/mL) in the syringe-pump system, the addition of 1% human serum albumin was necessary to prevent significant drug absorption to the polypropylene drug reservoir.

Studies of cloned simian immunodeficiency virus-specific T lymphocytes. gag-specific cytotoxic T lymphocytes exhibit a restricted epitope specificity

CD8+ CTL inhibit the replication of HIV and simian immunodeficiency virus of macaques (SIVmac) in PBL and, therefore, are likely to play an important role in containing the spread of the AIDS virus in infected individuals. We have generated a series of gag-specific lytic T lymphocyte clones from PBL: of an SIVmac-infected rhesus monkey. These T cell clones are CD3+CD8+ and are MHC class I-restricted in their target specificity. They are, therefore, CTL. Interestingly, all gag-specific CTL clones, as well as the gag-specific lytic activity of PBL of this monkey, demonstrated specificity for a single 25 amino acid fragment of the SIVmac gag protein. Moreover, they were restricted in their lytic function by a single MHC class I allele. These findings illustrate a powerful method for cloning AIDS virus-specific T lymphocytes and demonstrate a remarkably restricted epitope specificity of this AIDS virus-specific CTL response.

Studies of cloned simian immunodeficiency virus-specific T lymphocytes. gag-specific cytotoxic T lymphocytes exhibit a restricted epitope specificity

CD8+ CTL inhibit the replication of HIV and simian immunodeficiency virus of macaques (SIVmac) in PBL and, therefore, are likely to play an important role in containing the spread of the AIDS virus in infected individuals. We have generated a series of gag-specific lytic T lymphocyte clones from PBL: of an SIVmac-infected rhesus monkey. These T cell clones are CD3+CD8+ and are MHC class I-restricted in their target specificity. They are, therefore, CTL. Interestingly, all gag-specific CTL clones, as well as the gag-specific lytic activity of PBL of this monkey, demonstrated specificity for a single 25 amino acid fragment of the SIVmac gag protein. Moreover, they were restricted in their lytic function by a single MHC class I allele. These findings illustrate a powerful method for cloning AIDS virus-specific T lymphocytes and demonstrate a remarkably restricted epitope specificity of this AIDS virus-specific CTL response.

The murine complement receptor gene family. III. The genomic and transcriptional complexity of the Crry and Crry-ps genes

The murine CR genes Crry (previously termed mCRY) and Crry-ps (previously termed mCRX) are two distinct, but related, sequences which are the evolutionary homologs to sequences contained within the human CR1 gene. Screening a BALB/c genomic DNA library with the Crry/Crry-ps specific cDNA resulted in the isolation of two clusters of genomic sequences: those specific for Crry and those specific for Crry-ps. The coding sequences of the Crry gene encompass over 25 kb of DNA, whereas the Crry-ps sequences are included within a single 5.6-kb Eco-R1 fragment. The Crry gene consists of 10 separate exons. The first of these contains both the signal sequence and an alternatively spliced 129 bp present in approximately 10% of the Crry transcripts. Of the remaining exons, two encode a single sixty amino acid repeat domain each (A and E), two encode a split sixty amino acid repeat (B), and another encodes two 60 amino acid domains (C and D) fused as one exon. The transmembrane and cytoplasmic regions are both split into two exons each. RNA protection analysis indicates that although there is alternative splicing in the 5' region of the gene, the 3' exons encoding the terminal 60 amino acid repeat, the transmembrane region and cytoplasmic exons are used in the same order in all Crry transcripts. This suggests that the Crry gene product is not found as a secreted protein, but only as a cell surface bound protein. DNA sequence analysis of the Crry-ps gene indicates that this sequence most likely represents a pseudogene resulting from a processed mRNA transcript from the Crry gene. This conclusion is based on the lack of intervening sequences in the Crry-ps gene and the observation that the Crry-ps gene sequence contains both an 11-bp deletion within the "coding" region and a degenerate poly A tail at the 3' end of the homologous sequence. Additionally, RNA protection analysis indicates that mRNA cannot be detected which matches the Crry-ps sequence.

The murine complement receptor gene family. III. The genomic and transcriptional complexity of the Crry and Crry-ps genes

The murine CR genes Crry (previously termed mCRY) and Crry-ps (previously termed mCRX) are two distinct, but related, sequences which are the evolutionary homologs to sequences contained within the human CR1 gene. Screening a BALB/c genomic DNA library with the Crry/Crry-ps specific cDNA resulted in the isolation of two clusters of genomic sequences: those specific for Crry and those specific for Crry-ps. The coding sequences of the Crry gene encompass over 25 kb of DNA, whereas the Crry-ps sequences are included within a single 5.6-kb Eco-R1 fragment. The Crry gene consists of 10 separate exons. The first of these contains both the signal sequence and an alternatively spliced 129 bp present in approximately 10% of the Crry transcripts. Of the remaining exons, two encode a single sixty amino acid repeat domain each (A and E), two encode a split sixty amino acid repeat (B), and another encodes two 60 amino acid domains (C and D) fused as one exon. The transmembrane and cytoplasmic regions are both split into two exons each. RNA protection analysis indicates that although there is alternative splicing in the 5' region of the gene, the 3' exons encoding the terminal 60 amino acid repeat, the transmembrane region and cytoplasmic exons are used in the same order in all Crry transcripts. This suggests that the Crry gene product is not found as a secreted protein, but only as a cell surface bound protein. DNA sequence analysis of the Crry-ps gene indicates that this sequence most likely represents a pseudogene resulting from a processed mRNA transcript from the Crry gene. This conclusion is based on the lack of intervening sequences in the Crry-ps gene and the observation that the Crry-ps gene sequence contains both an 11-bp deletion within the "coding" region and a degenerate poly A tail at the 3' end of the homologous sequence. Additionally, RNA protection analysis indicates that mRNA cannot be detected which matches the Crry-ps sequence.

The gag-specific cytotoxic T lymphocytes in rhesus monkeys infected with the simian immunodeficiency virus of macaques

The simian immunodeficiency virus of macaques (SIVmac) is a lentivirus which induces an AIDS-like disease in rhesus monkeys. We have explored the virus-specific cellular immune response in SIVmac-infected rhesus monkeys. Con A-activated, IL-2 expanded PBL of some SIVmac-infected rhesus monkeys lyse autologous B lymphoblastoid cell lines infected with a recombinant vaccinia virus that carries the SIVmac gag gene. This lysis is mediated by CD8+ lymphocytes and is MHC class I restricted. Moreover, these effector lymphocytes do not express the NK cell-associated molecules NKH1 or CD16. These cells are, therefore, CTL. In a limited prospective study of SIVmac-infected rhesus monkeys, the presence of the SIVmac gag-specific CTL activity in PBL correlated with both a reduced efficiency in isolating SIVmac from PBL of these monkeys and their extended survival. This method for assessing SIVmac gag-specific cellular immunity in rhesus monkeys will be important not only in investigating the immunopathogenesis of SIVmac-induced disease, but also in evaluating the capacity of candidate AIDS vaccines to elicit a cell-mediated immune response in this animal model.

Medical student attitudes toward elderly patients: effects of social attractiveness

The purpose of this study was to determine if medical students' attitudes toward the elderly can be modified through social attractiveness cues in the form of descriptions of abilities and photographs of the patients. The results indicated that students were most personally and professionally attracted to the mentally alert patient, and they were most personally attracted to the patient whose photograph was included in the medical record. Furthermore, inclusion of previous and current photographs had a mediating effect on attitude formation and the formation of stereotypes. These results suggest that presenting social attractiveness information may be useful in countering negative perceptions of the elderly.

The gag-specific cytotoxic T lymphocytes in rhesus monkeys infected with the simian immunodeficiency virus of macaques

The simian immunodeficiency virus of macaques (SIVmac) is a lentivirus which induces an AIDS-like disease in rhesus monkeys. We have explored the virus-specific cellular immune response in SIVmac-infected rhesus monkeys. Con A-activated, IL-2 expanded PBL of some SIVmac-infected rhesus monkeys lyse autologous B lymphoblastoid cell lines infected with a recombinant vaccinia virus that carries the SIVmac gag gene. This lysis is mediated by CD8+ lymphocytes and is MHC class I restricted. Moreover, these effector lymphocytes do not express the NK cell-associated molecules NKH1 or CD16. These cells are, therefore, CTL. In a limited prospective study of SIVmac-infected rhesus monkeys, the presence of the SIVmac gag-specific CTL activity in PBL correlated with both a reduced efficiency in isolating SIVmac from PBL of these monkeys and their extended survival. This method for assessing SIVmac gag-specific cellular immunity in rhesus monkeys will be important not only in investigating the immunopathogenesis of SIVmac-induced disease, but also in evaluating the capacity of candidate AIDS vaccines to elicit a cell-mediated immune response in this animal model.