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Biomedical subjects

P Gottlieb

Publications and source records attributed to P Gottlieb.

At least 19 recordsLinked to original sources
PubMed2006

Initial results of screening of nondiabetic organ donors for expression of islet autoantibodies.

CONTEXT: Type 1A diabetes is characterized by a long prodromal phase during which autoantibodies to islet antigens are present. Nevertheless, we lack data on the pancreatic pathology of subjects who are positive for islet autoantibodies (to islet autoantigens GAD65, insulin, and ICA512). OBJECTIVE: In this manuscript, we describe a novel strategy in obtaining pancreata and pancreatic lymph nodes from islet autoantibody-positive organ donors that involves careful coordination among the laboratory and the organ donor provider organization. DESIGN: We developed a rapid screening protocol for islet autoantibodies measurement of organ donors to allow identification of positive subjects before organ harvesting. In this way we were able to obtain pancreata and pancreatic lymph nodes from subjects with and without islet autoimmunity. SETTING: The organ donors used in this study were obtained from the general community. SUBJECTS: The population studied consisted of 112 organ donors (age range 1 month to 86 yr, mean age 39 yr). MAIN OUTCOME MEASURE: The main outcome measure of this study consisted of evaluating the pancreatic histology and identify T cells autoreactive for islet antigens in the pancreatic lymph nodes. RESULTS: To date we have identified three positive subjects and obtained the pancreas for histological evaluation from one of the autoantibody-positive donors who expressed ICA512 autoantibodies. Although this subject did not exhibit insulitis, lymphocytes derived from pancreatic lymph nodes reacted to the islet antigen phogrin. CONCLUSION: In summary, these results indicate that it is possible to screen organ donors in real time for antiislet antibodies, characterize pancreatic histology, and obtain viable T cells for immunological studies.

Adolescent↗
PubMed2006

The wandering spleen: CT findings and possible pitfalls in diagnosis.

AIM: To report the CT features of wandering spleen, a rare condition which can be incidentally detected as an abdominal or pelvic mass or can present with torsion, causing an acute abdomen. MATERIALS AND METHODS: The CT studies of seven patients, two children and five adults, with wandering spleen were reviewed. CT was performed urgently in three patients for acute abdomen, and electively in four. RESULTS: CT findings of wandering spleen included absence of the spleen in its normal position and a mass located elsewhere in the abdomen or pelvis, i.e. an ectopic spleen, enhancing homogeneously in four cases and failing partially or completely to enhance in the other three, indicating infarction. A "whirl" appearance representing the twisted splenic pedicle was seen in the three cases with torsion. Urgent splenectomy confirmed infarction secondary to torsion. CONCLUSION: The possible diagnosis of wandering spleen should be kept in mind when CT shows the spleen to be absent from its usual position and a mass is found elsewhere in the abdomen or pelvis. When, in addition, a "whirl" or partial or no enhancement of this mass are seen in a case presenting with acute abdomen, torsion of a wandering spleen is a likely diagnosis.

Abdomen, Acute↗
PubMed2001

Using nucleotide analogs to probe protein-RNA interactions.

Synthetic nucleotide analogs provide the opportunity to evaluate the importance of individual functional groups on the RNA in protein-RNA complexes. The general approach is to incorporate analogs at a defined position(s) in the RNA target and to evaluate the effect of this substitution on the thermodynamic stability of the protein-RNA complex. The underlying assumption is that if the presence of the analog reduces the stability of the complex, then the functional groups that are altered in the analog interact with the protein. Here we describe the protocols for incorporation of nucleotide analogs either by in vitro transcription using T7 RNA polymerase or by synthetic chemistry. We also describe how we have used this approach to study the interaction of the TRAP protein from Bacillus subtilis with its cognate RNAs consisting of 11 repeats of GAG and/or UAG triplets. By comparing the results of these analog studies with the crystal structure of TRAP bound to an RNA containing 11 GAG repeats, we are able to see that all the functional groups identified by analogs forge direct interactions with the protein. Analog studies also correctly identified residues that do not contact the protein. Moreover, analogs can have indirect effects on the complex stability by altering the structural properties of the RNA.

Bacillus subtilis↗
PubMed2000

Dual overlapping peptides recognized by insulin peptide B:9-23 T cell receptor AV13S3 T cell clones of the NOD mouse.

T cells isolated from islets of non-obese diabetic (NOD) mice are enriched for insulin-reactive cells. The great majority of these T cells recognize insulin B chain peptide (B:9-23). B:9-23 reactive T cell clones are diabetogenic and show a dramatic TCR alpha -chain restriction (predominant AV13S3). We have studied the reactivity of five different B:9-23 reactive T cell clones to truncated peptides and alanine substituted analogues of B:9-23. Amongst these AV13S3 T cell clones, one reacted with peptide B:9-16 and four with B:13-23. The two peptides have in common only four amino acids (B:13-16; EALY). Having defined minimal peptide epitopes, we evaluated a mutant insulin sequence (B:13 glutamine) which retains metabolic activity. As predicted, this single amino acid change abrogated T cell reactivity. In addition, we have created a modified I-A(g7)gene with the B:9-23 peptide covalently linked to I-A(g7). Antigen presenting cells transfected with this construct were excellent presenting cells for all clones studied. The definition of dual peptide motifs and creation of bioactive covalent I-A(g7)-B:9-23 should facilitate studies of the pathogenic significance and antigen recognition by B:9-23 reactive diabetogenic T cells.

Alanine↗
PubMed2000

Non-neoplastic intratesticular lesions mimicking tumour on ultrasound.

It has recently been emphasized that the incidence of benign testicular lesions is much higher than previously suspected. Sonography is reported to have a high sensitivity but poor specificity in the evaluation of intratesticular abnormalities. This report reviews the common and unusual lesions that can mimic testicular tumour on ultrasound, and discusses the clinical and sonographic features that may help to narrow the differential diagnosis and guide management.

Diagnosis, Differential↗
PubMed1997

T cell receptor restriction of diabetogenic autoimmune NOD T cells.

Restricted use of T cell receptor (TCR) gene segments is characteristic of several induced autoimmune disease models. TCR sequences have previously been unavailable for pathogenic T cells which react with a defined autoantigen in a spontaneous autoimmune disease. The majority of T cell clones, derived from islets of NOD mice which spontaneously develop type I diabetes, react with insulin peptide B-(9-23). We have sequenced the alpha and beta chains of TCRs from these B-(9-23)-reactive T cell clones. No TCR beta chain restriction was found. In contrast, the clones (10 of 13) used V alpha13 coupled with one of two homologous J alpha segments (J alpha45 or J alpha34 in 8 of 13 clones). Furthermore, 9 of 10 of the V alpha13 segments are a novel NOD sequence that we have tentatively termed V alpha13.3. This dramatic alpha chain restriction, similar to the beta chain restriction of other autoimmune models, provides a target for diagnostics and immunomodulatory therapy.

Amino Acid Sequence↗
PubMed1996

Inactivation by phthalocyanine photosensitization of multiple forms of human immunodeficiency virus in red cell concentrates.

BACKGROUND: The use of phthalocyanines in conjunction with red light has been shown to inactivate model lipid-enveloped viruses in red cell concentrates. The ability of this treatment to inactivate multiple forms of human immunodeficiency virus (HIV) was evaluated in this study. STUDY DESIGN AND METHODS: The phthalocyanines used were aluminum phthalocyanine tetrasulfonate (AIPcS4) and the silicon phthalocyanines HOSiPcOSi(CH3)2(CH2)3 N(CH3)2 (Pc 4), and HOSiPcOSi(CH3)2 (CH2)3N+(CH3)3I-(Pc 5). HIV was studied in a cell-free form, in an actively replicating form, in latently infected cells, and in blood from HIV-positive patients. RESULTS: All three phthalocyanines inactivate > or = 10(5) infectious doses of cell-free HIV. However, only Pc 4 effectively inactivated actively replicating HIV and latently infected cells. The latter was about four times as sensitive to inactivation as was actively replicating HIV. Increasing the hematocrit of red cells during treatment decreased the rate of inactivation, especially at lower light doses. Under treatment conditions that completely inactivated the laboratory isolates of HIV, cell-associated HIV in blood from HIV-positive patients was also completely inactivated. The polymerase chain reaction signal from the gag gene of HIV was not affected on treatment of cell-free virus, but it was reduced after treatment of cell-associated HIV, particularly in some latently infected cell lines. CONCLUSION: Pc 4 and red light are effective in eliminating the infectivity of HIV in red cell concentrates. The usefulness of this approach for blood banking depends on future demonstration of the preservation of red cell circulatory survival and function in vivo.

Base Sequence↗
PubMed1996

Inactivation of Trypanosoma cruzi trypomastigote forms in blood components with a Psoralen and Ultraviolet A light.

Inactivation of the blood-borne parasite Trypanosoma cruzi by UVA and 4'-aminomethyl-4,5',8-trimethylpsoralen (AMT) was studied in the blood components fresh frozen plasma (FFP) and platelet concentrate (PC). The AMT was utilized at a concentration of 50 micrograms/mL and the inactivation procedure included the flavonoid rutin (at 0.35 mM), a quencher of type I and type photo-reactants, which we have previously found to maintain platelet integrity during this treatment regimen. Within both FFP and PC, complete inactivation of the infective form of T. cruzi, the trypomastigote, was achieved at a UVA (320-400 nm radiation) fluence of 4.2 J/cm2. We note that while the infectivity of the parasite is eliminated at 4.2 J/cm2 the trypomastigote motility continues for at least 16 h-post-treatment and is inhibited only after much higher light doses. Isolation of total DNA from the parasite cells after treatment in the presence of 3H-AMT indicated that at the lethal UVA influence about 0.5 AMT adducts per kilobase pairs occurred. These results suggest that this psoralen plus UVA methodology which shows promise in enhancing the viral safety of PC, may in addition eliminate bloodborne T. cruzi, the causative agent of Chagas disease.

Animals↗
PubMed1995

Virucidal short wavelength ultraviolet light treatment of plasma and factor VIII concentrate: protection of proteins by antioxidants.

The use of solvent/detergent mixtures and various forms of heat treatment to inactivate viruses has become widespread in the preparation of blood derivatives. Because viruses that lack lipid envelopes and/or are heat resistant, eg, hepatitis A virus (HAV) or parvovirus B19 may be present, the use of two methods of virus elimination that operate by different mechanisms has been advocated. We now report on short wavelength ultraviolet light (UVC) irradiation for virus inactivation and enhancement of its compatibility with proteins by quenchers of reactive oxygen species (ROS). Treatment of an antihemophilic factor (AHF) concentrate or whole plasma with 0.1 J/cm2 inactivated 10(5) to > or = 10(6) infectious doses (ID) of encephalomyocarditis virus (EMCV), HAV, bacteriophage M13, vesicular stomatitis virus (VSV), and porcine parvovirus. However, the recovery of factor VIII was 30% or lower on treatment of an AHF concentrate and 60% on treatment of plasma. Factor VIII recovery could be increased with little or no effect on virus kill by addition of rutin, a flavonoid known to quench both type I and type II ROS. On treatment of plasma in the presence of rutin, the recovery of several other coagulation factors was also enhanced by rutin addition and typically exceeded 75%. Electrophoretic analysis of treated AHF concentrate confirmed the advantage of rutin presence; UVC irradiation of plasma did not cause discernible changes in electrophoretic banding patterns, even in the absence of rutin. We conclude that addition of UVC treatment to existing processes used in the manufacture of blood derivatives will provide an added margin of safety, especially for nonenveloped or heat-stable viruses.

Animals↗
PubMed1995

Inactivation of Trypanosoma cruzi trypomastigote forms in blood components by photodynamic treatment with phthalocyanines.

Three phthalocyanine dyes HOSiPcOSi(CH3)2(CH2)3N(CH3)2 (Pc 4), HOSiPcOSi(CH3)2(CH2)3N+(CH3)3I- (Pc 5) and aluminum tetrasulfophthalocyanine hydroxide (AlOHPcS4) were evaluated for their ability to inactivate the trypomastigote form of Trypanosoma cruzi in fresh frozen plasma (FFP) and red blood cell concentrates (RBCC). The compound Pc 4 was found to be highly effective in killing T. cruzi, Pc 5 less effective and AlOHPcS4 ineffective. With FFP as the medium, a complete loss of parasite infectivity in vitro (> or = 5 log10) was found to occur with 2 microM Pc 4 after irradiation with red light (> 600 nm) at a fluence of 7.5 J/cm2, while with RBCC as the medium, a complete loss was found to occur at a fluence of 15 J/cm2. Even without illumination, Pc 4 at 2 microM also killed about 3.7-4.1 log10 of T. cruzi in FFP during 30 min. Observed differences in T. cruzi killing by the various phthalocyanines may related to differences in binding; Pc 4 binds to the parasites about twice as much as Pc 5. Ultrastructural analysis of treated parasites suggests that mitochondria are a primary target of this photodynamic treatment. The data indicate that Pc 4 combined with exposure to red light could be used to eliminate bloodborne T. cruzi parasites from blood components intended for transfusion. The inactivation of T. cruzi by Pc 4 in the dark suggests a possible therapeutic application.

Animals↗
PubMed1994

[Status of forensic patients in the health system].

Forensic patients can be defined as patients subjected to a criminal law trial procedure or cases for whom a court decision has been taken at the time of treatment. The forensic cases may be subdivided into the following categories: Pre-trial: 1. Cases transferred to hospital as substitution for remand prison. 2. Cases transferred to hospital anticipating a verdict of admission to psychiatric hospital. 3. Cases transferred to hospital on a medical decision alone. 4. Cases admitted for examination to establish a psychiatric court report. Post-trial: 1. Cases sentenced to psychiatric treatment. 2. Cases serving a sentence. 3. Cases subjected to a condition of psychiatric treatment. For each group legislation and precepts concerning distribution of cases among hospitals, special requirements, rights and restrictions are expounded. The application of the "Civil Psychiatry Law of 1989" is discussed with reference to the forensic cases categories. Guidelines for the reception of forensic cases in psychiatric hospital departments are indicated.

Civil Rights↗
PubMed1994

Identification of the packaging regions within the genomic RNA segments of bacteriophage phi 6.

Bacteriophage phi 6 has a genome of three segments of double-stranded RNA enclosed in a procapsid composed of four different proteins. The preformed procapsid is capable of packaging plus-strand transcripts of the genomic segments in an in vitro reaction. The packaging-specific sequences on the RNA molecules are located near the 5' ends. In this study we show that the packaging sequences are different for each of the three segments and that they are of about 250 nucleotides in length. Although these sequences are consistent with some secondary structure, there is no clear structural similarity between the packaging regions of the three segments.

Bacteriophage phi 6↗
PubMed1994

RNA structural requirements for stability and minus-strand synthesis in the dsRNA bacteriophage phi 6.

Bacteriophage phi 6 has a genome consisting of three segments of double-stranded RNA designated L, M, and S. Each virion contains one of each genomic segment. Empty procapsids can package plus-strand transcripts of the genomic segments if the 5' regions are intact. Minus-strand synthesis takes place if all three segments are packaged and if the 3' end of the segment is intact. The 3' ends of the segments contain four hairpin structures within a region of high sequence conservation. We now show that removal of parts of this region leads to progressive but limited loss of ability to support minus-strand synthesis. The defective 3' ends can be corrected by heterologous recombination with the termini of other segments. Segments that have small deletions in the conserved region and that support apparently normal minus-strand synthesis are highly recombinogenic.

Bacteriophage phi 6↗
PubMed1993

Molecular characterization of monoclonal CRIA-positive anti-arsonate antibodies derived from idiotype-negative mice bearing a light chain polymorphism.

We have elicited anti-arsonate antibodies bearing the major cross-reactive idiotype (CRIA) in a double congenic idiotype-negative strain (C.C58.AL-20) bearing a light chain polymorphism that has previously been shown serologically not to complement idiotype-positive heavy chains. Using the idiotype cascade (Ab1-->Ab2-->Ab3-->-->Ab1'), CRIA-positive antibodies were raised and monoclonal antibodies were isolated and characterized serologically and by nucleotide sequence analysis. Two types of idiotype-positive anti-arsonate antibodies were generated in the C.C58.AL-20 strain. One group of hybridomas used the canonical VH1.8 heavy chain gene segment with V kappa 10 variant light chains. A second group used a VHGAM3.8 heavy chain with V kappa 10 variant light chains. This latter heavy-light pairing has been observed in CRIA-like responses previously in BALB/c mice after idiotypic manipulation (or rarely after antigen alone). These studies demonstrate the plasticity of the immune response when manipulated with idiotype reagents as well as its structural variability. Additionally, they provide important insights into the potentials of idiotype vaccines.

Amino Acid Sequence↗