Identification of a Putative Precursor to the Major Surface Glycoprotein of Pneumocystis carinii

The major surface glycoprotein (MSG) of Pneumocystis carinii f. sp. carinii is a family of proteins encoded by a family of heterogeneous genes. Messenger RNAs encoding different MSGs each begin with the same 365-bp sequence, called the Upstream Conserved Sequence (UCS), which is in frame with the contiguous MSG sequence. The UCS contains several potential start sites for translation. To determine if translation of MSG mRNAs begins in the UCS, polyclonal antiserum was raised against the 123-amino-acid peptide encoded by the UCS. The anti-UCS serum reacted with a P. carinii protein that migrated at 170 kDa; however, it did not react with the mature MSG protein, which migrates at 116 kDa. A 170-kDa protein was immunoprecipitated with anti-UCS serum and shown to react with a monoclonal antibody against a conserved MSG epitope. To explore the functional role of the UCS in the trafficking of MSG, the nucleotide sequence encoding the UCS peptide was ligated to the 5′ end of an MSG gene and incorporated into a recombinant baculovirus. Insect cells infected with the UCS-MSG hybrid gene expressed a 160-kDa protein which was N-glycosylated. By contrast, insect cells infected with a baculovirus carrying an MSG gene lacking the UCS expressed a nonglycosylated 130-kDa protein. These data suggest that in P. carinii, translation begins in the UCS to produce a pre-MSG protein, which is subsequently directed to the endoplasmic reticulum and processed to the mature form by proteolytic cleavage.     

Simultaneous presentation of sarcoidosis and acute myeloid leukaemia: predisposition to pulmonary haemorrhage.

A case of coexistent acute myeloid leukaemia and sarcoidosis is reported. This was complicated by recurrent pulmonary haemorrhage during reinduction and consolidation chemotherapy. A review of published papers on malignancy and sarcoidosis, in particular acute leukaemia is given. The outcome of most cases of acute leukaemia and sarcoidosis is poor with respiratory complications a frequent cause of death in this group. It is proposed that modifications to treatment to avoid pulmonary toxicity and maintenance of platelet counts above 40 x 10(9)/l are warranted to reduce the risk of this complication.     

Minnesota Multiphasic Personality Inventory (MMPI) cluster groups among chronically ill patients: Relationship to illness adjustment and treatment outcome

Cluster analysis of the MMPI has been utilized widely in the chronic low back pain literature to try to identify reliable patient subtypes predictive of treatment outcome. We extended this methodology to patients with heterogeneous chronic medical conditions by replicating prototypic MMPI cluster group profiles and by relating cluster groups to clinical baseline and outcome data. Subjects were two independent samples (n=254 and n=263) of chronically ill patients admitted to an inpatient medicine/psychiatry unit. Using a four-cluster solution, similar cluster profile groups were replicated in both samples. Consistent differences emerged between cluster groups on functional impairment, psychiatric diagnoses, depression, and psychosomatic symptoms. Cluster group membership also predicted changes in functional impairment and depression six months after treatment. Results are discussed in terms of similarities between chronic low back pain and chronic illness and tailoring treatment to different patient types.This research was supported in part by a grant from the Henry J. Kaiser Family Foundation.     

Immunotherapy of mammary adenocarcinoma metastases in C3H/HeN mice with chronic administration of cyclo-oxygenase inhibitors alone or in combination with IL-2

In this study the efficacy of treatment of two cyclo-oxygenase inhibitors, ibuprofen (Ibu) and indomethacin (Indo), are compared in the immunotherapy of metastasis designed to reverse prostaglandin E₂ (PGE₂)mediated inactivation of interleukin-2 (IL-2)-dependent host killer cell lineages. These agents were tested either alone for the prevention of metastasis or in combination with IL-2 for the eradication of established metastasis. C3H/HeN mice were placed on chronic oral Ibu (CIbT; 200 and 600 ,g/ml of water) or Indo (CIT; 10 g/ml) 5 days after s.c. transplantation of 5 × 10⁵ metastatic C3L5 mammary carcinoma for the prevention of spontaneous lung metastases. They showed intolerance to Indo at a dosage of 14 g/ml, which was well tolerated by other mouse strains in previous studies, but tolerated the Ibu dosages used. Control and treated mice were killed on day 30 to score metastatic lung colonies, to evaluate killer activity in splenocytes against natural killer (NK)-sensitive YAC-1 lymphoma or NK-resistant C3L5 adenocarcinoma and 8911 lymphoma targets, and to phenotype the surface markers of killer cells. CIbT and CIT alone at the above dosage significantly reduced the number of lung colonies, retarded local tumor growth and restored NK activity of splenic killer cells expressing AGM-1⁺, Thy-1^–, Lyt-2^– phenotype. To treat established lung metastasis, mice bearing 15-day C3L5 transplants were given CIbT or CIT alone or in combination with two 4-day rounds (days 20–23, 31–34) of IL-2 (15 000 Cetus units, i.p. every 8 h) and were killed on day 35 to score lung colonies and characterize splenic killer cells. CIbT or CIT alone reduced the number of spontaneous lung metastases and restored anti-YAC-1 killer function of splenocytes with NK-like phenotype (AGM-1⁺, Thy-1^–, Lyt-2^–); some anti-C3L5 killer function was also generated in the high dose Ibu group and the killer cell showed AGM-1⁺, Thy-1⁺ and Lyt-2⁺ phenotype. Combined therapies with CIbT or CIT plus IL-2 were more effective in reducing metastases and promoting killer cell function, the best results being achieved with high dose Ibu + IL-2. All killer cells expressed AGM-1 and Thy-1. In addition, C3L5 killer cells also expressed Lyt-2, suggesting T-cell stimulation. PGE₂ synthesis in the host was inhibited by at least 50% in mice subjected to CIbT or CIT. Thus, Ibu proved to be an excellent substitute for Indo in preventing metastasis and NK cell activation when given alone, and also in ameliorating established metastasis and activating lymphokine-activated killer cells when combined with IL-2.     

Use of polymerase chain reaction for rapid diagnosis of tuberculosis.

A DNA amplification assay using the polymerase chain reaction technique designed for the rapid identification of Mycobacterium bovis organisms was used to test 211 human mycobacterial isolates and 177 clinical specimens previously submitted for routine mycobacterial culture. The procedures described could be used by routine or specialist laboratories for identification of M. tuberculosis complex organisms in 4 h and/or as a rapid screening method for the direct detection of M. tuberculosis complex organisms in specimens.     

Knowledge,attitudes and practices towards HIV positive and AIDS patients among public service dentists in Nairobi

The purpose of this study was to assess the knowledge, practices and attitudes towards HIV Positive/AIDS patients among 112 dentists from public institutions in Nairobi using a self-administered questionnaire. 94(83.9%) responded. Over 74% had managed HIV positive/AIDS patients. In general, respondents' knowledge and preventive measures against HIV infection were satisfactory. 8.5% did not find use of protective eye wear absolutely necessary. 33% used protective covers routinely. 52.1% advocated for the screening of all suspected cases of AIDS before treatment. 27.7% felt that HIV positive health workers and those with AIDS should not be allowed to treat patients. 53.2% felt that they should be given the right to decide on treating HIV Positive/AIDS patients. 10.6% supported the idea that AIDS patients be isolated from uninfected individuals. It is concluded that a substantial number of dentists were wanting in their attitudes towards HIV positive/AIDS patients.     

The complete sequence of the coding region of the ATM gene reveals similarity to cell cycle regulators in different species

Ataxia-telangiectasia (A-T) is an autosomal recessive disorderinvolving cerebellar degeneration, immunodeficiency, radiationsensitivity, and cancer predisposition. A-T heterozygotes aremoderately cancer prone. The A-T gene, designated ATM, was recentlyidentified in our laboratory by positional cloning, and a partialcDNA clone was found to encode a polypeptide with a PI-3 kinasedomain. We report here the molecular cloning of a cDNA contigspanning the complete open reading frame of the ATM gene. Thepredicted protein of 3056 amino acids shows significant sequencesimilarities to several large proteins in yeast, Drosophilaand mammals, all of which share the PI-3 kinase domain. Manyof these proteins are involved in the detection of DNA damageand the control of cell cycle progression. Mutations in theirgenes confer a variety of phenotypes with features similar tothose observed in human A-T cells. The complete sequence ofthe ATM gene product provides useful clues to the function ofthis protein, and furthers understanding of the pleiotropicnature of the A-T mutations.     

Effect of synthetic lipopeptides formulated in liposomes on the maturation of human dendritic cells

Diacylated (e.g. MALP-2) and triacylated (Pam(3)Cys derivatives) lipopeptides, deriving from the N-terminal moiety of respectively mycoplasmal and E. coli lipoproteins, are powerful adjuvants recognized by Toll-like receptors (TLR) which have been used successfully to trigger cell activation and immune responses. To design liposome-based vaccination constructs in which Th and CTL epitopes are conjugated to synthetic lipopeptide analogues anchored into the bilayers of the vesicles, the peptide moieties of the lipopeptides were functionalized with thiol-reactive groups, such as maleimide (Mal) or bromoacetyl, incorporated into liposomes and reacted with thiol carrying peptide epitopes. Because dendritic cells (DCs) play a key role as antigen-presenting cells in immune responses, in the present study we have evaluated the impact of the functionalization of lipopeptide analogues Pam(2)CAG, Pam(3)CAG and Ol(3)GAG on the phenotypic maturation of human monocyte-derived DCs. The intrinsic cellular activities of the lipopeptide analogues incorporated into liposomes were monitored, in vitro, by measuring the up-regulation of the cell-surface markers CD80, CD83, CD86 and HLA-DR. We found that in some cases their functionalization with thiol-reactive groups led to a loss of activity. The stimulatory potency can be ranked in the following order: Pam(3)CAG>/=Pam(2)CAG-Mal-Th approximately Pam(2)CAG-Mal>Pam(3)CAG-Mal-Th (where Th is a HS-peptide) and no appreciable activity was detected for Pam(3)CAG-Mal, Ol(3)CAG-Mal and Ol(3)CAG-Mal-Th. Our findings indicate that subtle modifications in the peptide moiety of lipopeptides have a great impact on the immunomodulatory properties of these molecules. For the engineering of liposome/lipopeptide-based vaccines, the maleimide derivative of Pam(2)CAG appears to be the best candidate.     

Fibrinogen stabilizes placental-maternal attachment during embryonic development in the mouse

In humans, maternal fibrinogen (Fg) is required to support pregnancies by maintaining hemostatic balance and stabilizing uteroplacental attachment at the fibrinoid layer found at the fetal-maternal junction. To examine relationships between low Fg levels and early fetal loss, a genetic model of afibrinogenemia was developed. Pregnant mice homozygous for a deletion of the Fg-gamma chain, which results in a total Fg deficiency state (FG(-/-)), aborted the fetuses at the equivalent gestational stage seen in humans. Results obtained from timed matings of FG(-/-) mice showed that vaginal bleeding was initiated as early as embryonic day (E)6 to 7, a critical stage for maternal-fetal vascular development. The condition of afibrinogenemia retarded embryo-placental development, and consistently led to abortion and maternal death at E9.75. Lack of Fg did not alter the extent or distribution pattern of other putative factors of embryo-placental attachment, including laminin, fibronectin, and Factor XIII, indicating that the presence of fibrin(ogen) is required to confer sufficient stability at the placental-decidual interface. The results of these studies demonstrate that maternal Fg plays a critical role in maintenance of pregnancy in mice, both by supporting proper development of fetal-maternal vascular communication and stabilization of embryo implantation.     

Medical students' attitudes in a PBL curriculum: trust, altruism, and cynicism.

PURPOSE: Studies have shown that medical students become more cynical and less altruistic as they advance in training. However, these studies were conducted in traditional medical schools, and many used unvalidated tools. This study examined students' attitudes in a problem-based learning (PBL) curriculum using reliable and valid measures. METHOD: Medical students and PGY-1 residents at Mercer University School of Medicine in Macon, Georgia, completed Wrightsman's Philosophies of Human Natures Scale (PHNS) in 1999 and 2000. Chronbach's alpha assessed internal reliability among subscales, and test-retest reliability coefficients confirmed acceptable reliability. For 114 students who completed both surveys, changes in PHNS scores were analyzed, with particular attention to the subscales of trustworthiness, altruism, and cynicism. RESULTS: Students assessed at the beginning of their second year increased the extent to which they believed people are trustworthy and increased their beliefs in how altruistic people are. They also showed a significant decrease in cynicism. There was not a significant change in trustworthiness, altruism, or cynicism among the participants beyond first year. In general, female students held less cynical views about others and believed people to be more trustworthy. CONCLUSIONS: Contrary to prior reports, this study found that more advanced trainees were not more cynical or less altruistic than their more junior counterparts. Indeed, a significant and positive change of attitudes among the participants during their first year of medical school refuted earlier reports. Thus, results of earlier studies and the effect of a PBL curriculum on attitudes of medical students need to be re-examined.