Biomedical subjects

S Stein

Publications and source records attributed to S Stein.

At least 19 recordsLinked to original sources

PubMed2006

Memory of childbirth in the second year: the long-term effect of a negative birth experience and its modulation by the perceived intranatal relationship with caregivers.

OBJECTIVE: To assess the memory of various subdimensions of the birth experience in the second year postpartum, and to identify women in the first weeks postpartum at risk of developing a long-term negative memory. DESIGN, METHOD, OUTCOME MEASURES: New mothers' birth experience (BE) was assessed 48-96 hours postpartum (T1) by means of the SIL-Ger and the BBCI (perception of intranatal relationships); early postnatal adjustment (week 3 pp: T1(bis)) was also assessed. Then, four subgroups of women were defined by means of a cluster-analysis, integrating the T1/T1(bis) variables. To evaluate the memory of the BE, the SIL-Ger was again applied in the second year after childbirth (T2). First, the ratings of the SIL-Ger dimensions of T1 were compared to those at T2 in the whole sample. Then, the four subgroups were compared with respect to their ratings of the birth experience at T2 (correlations, ANOVAs and t-tests). RESULTS: In general, fulfillment, emotional adaptation, physical discomfort, and anxiety improve spontaneously over the first year postpartum, whereas in negative emotional experience, control, and time-going-slowly no shift over time is observed. However, women with a negative overall birth experience and a low level of perceived intranatal relationship at T1 run a high risk of retaining a negative memory in all of the seven subdimensions of the birth experience. CONCLUSIONS: Women at risk of developing a negative long-term memory of the BE can be identified at the time of early postpartum, when the overall birth experience and the perceived intranatal relationship are taken into account.

Adolescent↗

PubMed2005

Seismology: tectonic strain in plate interiors?

It is not fully understood how or why the inner areas of tectonic plates deform, leading to large, although infrequent, earthquakes. Smalley et al. offer a potential breakthrough by suggesting that surface deformation in the central United States accumulates at rates comparable to those across plate boundaries. However, we find no statistically significant deformation in three independent analyses of the data set used by Smalley et al., and conclude therefore that only the upper bounds of magnitude and repeat time for large earthquakes can be inferred at present.

Comment↗

PubMed2005

Tumor-specific targeting of an anticancer drug delivery system by LHRH peptide.

The central problem in cancer chemotherapy is the severe toxic side effects of anticancer drugs on healthy tissues. Invariably the side effects impose dose reduction, treatment delay, or discontinuance of therapy. To limit the adverse side effects of cancer chemotherapy on healthy organs, we proposed a drug delivery system (DDS) with specific targeting ligands for cancer cells. The proposed DDS minimizes the uptake of the drug by normal cells and enhances the influx and retention of the drug in cancer cells. This delivery system includes three main components: (i) an apoptosis-inducing agent (anticancer drug), (ii) a targeting moiety-penetration enhancer, and (iii) a carrier. We describe one of the variants of such a system, which utilizes camptothecin as an apoptosis-inducing agent and poly(ethylene glycol) as a carrier. Luteinizing hormone-releasing hormone (LHRH) was used as a targeting moiety (ligand) to LHRH receptors that are overexpressed in the plasma membrane of several types of cancer cells and are not expressed detectably in normal visceral organs. The results showed that the use of LHRH peptide as a targeting moiety in the anticancer DDS substantially enhanced the efficacy of chemotherapy, led to amplified apoptosis induction in the tumor, and minimized the side effects of the anticancer drug on healthy organs. The LHRH receptor targeting DDS did not show in vivo pituitary toxicity and did not significantly influence the time course or the plasma concentration of luteinizing hormone and its physiological effects on the reproductive functions of mice.

Animals↗

PubMed2004

Analysis of 683 drug packages seized from "body stuffers".

The wrappings and contents of 683 drug containers (bubbles) seized from 154 street dealers have been analysed since 2001, when the law enforcement policy in Hamburg, Germany, allowed the application of emetics to be used by so-called body stuffers for the recovery of swallowed drug packages. Of the bubbles recovered 96% contained cocaine. Cases of intoxication have not yet been observed but a 20-year-old man with a previously unknown toxic cardiomyopathy died 3 days after a sudden cardiac arrest which followed the forced application of ipecacuanha via correctly placed nasogastral tube.

Cocaine↗

PubMed2004

Three dimensional analysis of histone methylation patterns in normal and tumor cell nuclei.

Histone modifications represent an important epigenetic mechanism for the organization of higher order chromatin structure and gene regulation. Methylation of position-specific lysine residues in the histone H3 and H4 amino termini has linked with the formation of constitutive and facultative heterochromatin as well as with specifically repressed single gene loci. Using an antibody, directed against dimethylated lysine 9 of histone H3 and several other lysine methylation sites, we visualized the nuclear distribution pattern of chromatin flagged by these methylated lysines in 3D preserved nuclei of normal and malignant cell types. Optical confocal serial sections were used for a quantitative evaluation. We demonstrate distinct differences of these histone methylation patterns among nuclei of different cell types after exit of the cell cycle. Changes in the pattern formation were also observed during the cell cycle. Our data suggest an important role of methylated histones in the reestablishment of higher order chromatin arrangements during telophase/early G1. Cell type specific histone methylation patterns are possibly casually involved in the formation of cell type specific heterochromatin compartments, composed of (peri)centromeric regions and chromosomal subregions from neighboring chromosomes territories, which contain silent genes.

Cell Line, Tumor↗

PubMed2003

Molecular targeting of drug delivery systems to ovarian cancer by BH3 and LHRH peptides.

Novel targeted proapoptotic anticancer drug delivery systems were developed and evaluated. Poly(ethyleneglycol) (PEG) conjugates were used as carriers. Camptothecin (CPT) was used as an anticancer agent-apoptosis inductor. Two types of molecular targets were investigated: (1) an extracellular membrane receptor specific to ovarian cancer and (2) intracellular controlling mechanisms of apoptosis. Synthetic peptides similar to luteinizing hormone-releasing hormone (LHRH) and BCL-2 homology 3 (BH3) peptide were used as a targeting moiety and a suppressor of cellular antiapoptotic defense, respectively. Three different conjugates (CPT-PEG, CPT-PEG-BH3 and CPT-PEG-LHRH) were synthesized and examined in A2780 human ovarian cancer cells. Cytotoxicity, expression of genes encoding BCL-2, BCL-XL, SMAC, APAF-1 proteins and caspases 3 and 9, the activity of caspases 3 and 9 and apoptosis induction were studied. Taken together the results indicate much higher cytotoxicity and apoptosis-inducing activity of PEG-CPT conjugates when compared to free CPT. Moreover, the effects of targeted CPT-PEG-BH3 and CPT-PEG-LHRH conjugates were more pronounced than the non-targeted PEG-CPT conjugate. The results confirmed the feasibility of this new two-tier molecular targeting strategy for enhancing the efficacy of cancer chemotherapy.

Amino Acids↗

PubMed2003

ALFRED: the ALelle FREquency Database. Update.

Elaboration of ALFRED (http://alfred.med.yale.edu) is being continued in two directions. One of which is developing tools for efficiently annotating the entries and checking the integrity of the data already in the database while the other is to increase the quantity and accessibility of data. Information contained in ALFRED such as, polymorphic sites, number of populations and frequency tables (one sample typed for one site) has significantly increased.

Alleles↗

PubMed2003

[Rehabilitation after replantation].

Limb replantation represents a particular surgical challenge. Rehabilitation and functional integration of the patient into everyday life has proven to be as equally important as the operation itself. This requires intensive and long-term cooperation between surgeon, therapist, and patient since replanted limbs without restoration of function are of no use. Besides physiotherapy, ergotherapy is highly important for this since it helps to reactivate daily activities.Also, tactile gnosis and protecting nervous sensibility and motor function can be improved by ergotherapy. With the help of special devices, adjustments,and psychological care, ergotherapy also supports the patient's reintegration into his former social environment.

Activities of Daily Living↗

PubMed2003

Kinetics of cell death in T lymphocytes genetically modified with two novel suicide fusion genes.

Donor lymphocyte infusions (DLI) following allogeneic stem cell transplantation are known to mediate graft-versus-leukemia effect (GVL). A major side effect of these immunotherapies is the development of graft-versus-host diseases (GVHD). One promising approach to prevent GVHD is to genetically modify donor T cells with a suicide mechanism that can be induced in the case of GVHD. Here we report on a retroviral vector containing the death effector domain (DED) of the human Fas-associated protein with death domain (FADD). The DED was fused to two copies of an FKBP506-binding protein and a truncated version of the human low-affinity receptor for nerve growth factor (LNGFR). Activation of the death signal pathway can be triggered upon the addition of chemical inducers of dimerization. This construct was functionally compared to an optimized HSV-TK vector in which a hypersensitive mutant of the herpes simplex virus thymidine kinase gene (TK39) was fused to a cytoplasmic truncated version of the cell surface antigen CD34. A direct comparison between both vectors in primary T lymphocytes showed that the number of T cells transduced with vectors containing the DED was significantly reduced within 24 h of drug administration whereas ganciclovir treatment of TK39-transduced T cells showed a delay in cell death of approximately 3-4 days. Our results indicate that constructs containing the DED may prove to be the most efficient mechanism to quickly eliminate alloreactive T cells.

Antiviral Agents↗

PubMed2002

Differential display analysis of gene expression in mammals: a p53 story.

Differential display is used worldwide as a method to identify changes in gene expression and to discover novel genes that are involved in important biological pathways. The principle of differential display is the systematic amplification of the 3' termini of messenger RNAs by using anchored oligo-dT primers in combination with upstream arbitrary primers. The separation of the polymerase chain reaction products by gel electrophoresis and their direct comparison allows the identification of differentially regulated genes. Recently, fluorescent differential display was established as the first nonradioactive differential display system with equivalent sensitivity to originally 33P isotopic labeling method. Because of its simplicity, sensitivity, reproducibility and automation, which increase the throughput and accuracy, differential display has become one of the most widely used gene-screening methods in biomedical research involving mammals. This chapter provides a glimpse of the application of differential display in search of target genes of the p53 tumor suppressor gene.

Animals↗

PubMed2001

Targeted PEG-based bioconjugates enhance the cellular uptake and transport of a HIV-1 TAT nonapeptide.

We previously described the enhanced cell uptake and transport of R.I-K(biotin)-Tat9, a large ( approximately 1500 Da) peptidic inhibitor of HIV-1 Tat protein, via SMVT, the intestinal biotin transporter. The aim of the present study was to investigate the feasibility of targeting biotinylated PEG-based conjugates to SMVT in order to enhance cell uptake and transport of Tat9. The 29 kDa peptide-loaded bioconjugate (PEG:(R.I-Cys-K(biotin)-Tat9)8) used in these studies contained eight copies of R.I-K(biotin)-Tat9 appended to PEG by means of a cysteine linkage. The absorptive transport of biotin-PEG-3400 (0.6-100 microM) and the bioconjugate (0.1-30 microM) was studied using Caco-2 cell monolayers. Inhibition of biotin-PEG-3400 by positive controls (biotin, biocytin, and desthiobiotin) was also determined. Uptake of these two compounds was also determined in CHO cells transfected with human SMVT (CHO/hSMVT) and control cells (CHO/pSPORT) over the concentration ranges of 0.05-12.5 microM and 0.003-30 microM, respectively. Nonbiotinylated forms of these two compounds, PEG-3350 and PEG:(R.I-Cys-K-Tat9)8, were used in the control studies. Biotin-PEG-3400 transport was found to be concentration-dependent and saturable in Caco-2 cells (K(m)=6.61 microM) and CHO/hSMVT cells (K(m)=1.26 microM). Transport/uptake was significantly inhibited by positive control substrates of SMVT. PEG:(R.I-Cys-K(biotin)Tat9)8 also showed saturable transport kinetics in Caco-2 cells (K(m)=6.13 microM) and CHO/hSMVT cells (K(m)=8.19 microM). Maximal uptake in molar equivalents of R.I-Cys-K(biotin)Tat9 was 5.7 times greater using the conjugate versus the biotinylated peptide alone. Transport of the nonbiotinylated forms was significantly lower (P<0.001) in all cases. The present results demonstrate that biotin-PEG-3400 and PEG:(R.I-Cys-K(biotin)Tat9)8 interact with human SMVT to enhance the cellular uptake and transport of these larger molecules and that targeted bioconjugates may have potential for enhancing the cellular uptake and transport of small peptide therapeutic agents.

Animals↗

PubMed2001

Characterization of the mouse liver fructose-1,6-bisphosphatase gene.

A cDNA encoding fructose-1,6-bisphosphatase (FBPase) was isolated from mouse liver RNA. The cDNA encodes a polypeptide of 338 amino acids (36.9 kDa). The liver and muscle FBPase isoenzymes of the mouse show positional identities of 69% at the cDNA level and 72% at the protein primary structure level. Starting from genomic YAC libraries and based upon the cDNA sequence all functional parts of the mouse liver FBPase gene (including exon-intron boundaries) were PCR-amplified and sequenced. The 5'-flanking regions of the liver and muscle FBPase genes were compared and showed no sequence similarity. Both genes are co-localized at chromosome 13B3-C1. The transcriptional start site was assigned to a guanine 118 bases before the start codon in the liver FBPase gene. An analysis of the steady state mRNA levels of liver and muscle FBPase in various mouse tissues was performed by Northern blotting and RT/PCR.

Amino Acid Sequence↗

PubMed2001

HIV-positive patients with anal carcinoma have poorer treatment tolerance and outcome than HIV-negative patients.

PURPOSE: Anal carcinoma is being found in HIV-positive patients with increasing frequency. Most patients are treated with combined chemotherapy and radiation. It was our impression that HIV-positive patients do not fare as well as HIV-negative patients in terms of both response to and tolerance of therapy. METHODS: To test this hypothesis, we reviewed our experience with anal carcinoma and compared HIV-positive to HIV-negative patients by age, gender, sexual orientation, stage at diagnosis, treatment rendered, response to treatment, tolerance, and survival. From 1985 to 1998, 98 patients with anal neoplasms were treated. Seventy-three patients had invasive squamous-cell carcinoma (including cloacogenic carcinoma), and this cohort was analyzed. Thirteen patients were HIV positive and 60 were HIV negative. RESULTS: The HIV-positive and HIV-negative groups differed significantly by age (42 vs. 62 years, P < 0.001), male gender (92 vs. 42 percent, P < 0.001), and homosexuality (46 vs. 15 percent, P < 0.05). There were no differences by stage at diagnosis or radiation dose received. Acute treatment major toxicity differed significantly (HIV positive 80 percent vs. HIV negative 30 percent; P < 0.005). Only 62 percent of HIV-positive patients were rendered disease free after initial therapy vs. 85 percent of HIV-negative patients (P = 0.11). Median time to cancer-related death was 1.4 vs. 5.3 years (P < 0.05). A survival model did not show age, gender, stage, or treatment to be independent predictors. CONCLUSION: We found that HIV-positive patients with anal carcinoma seem to be a different population from HIV-negative patients by age, gender, and sexual orientation. They have a poorer tolerance for combined therapy and a shorter time to cancer-related death. A strong trend to poorer initial response rate was also seen. These results suggest that the treatment of HIV-positive patients with anal carcinoma needs to be reassessed.

Adult↗

PubMed2001

Targeting the sodium-dependent multivitamin transporter (SMVT) for improving the oral absorption properties of a retro-inverso Tat nonapeptide.

PURPOSE: To investigate the potential for delivering large peptides orally by altering their absorptive transport pathways and improving intestinal permeability. The absorptive transport of retro-inverso (R.I.-) K-Tat9 and R.I.-K(biotin)-Tat9, novel peptidic inhibitors of the Tat protein of HIV-1, and their interactions with human SMVT (hSMVT), a high affinity, low capacity transporter, were investigated using Caco-2 and transfected CHO cells. METHODS: Following synthesis on a PAL resin using Fmoc chemistry, the transport of R.I.-K-Tat9 (0.01-25 microM) and R.I.-K(biotin)-Tat9 (0.1-25 microM) was evaluated across Caco-2 cells. The transport and kinetics of biotin, biocytin and desthiobiotin (positive controls for SMVT) were also determined. Uptake of R.I.-K-Tat9 and R.I.K(biotin)-Tat9 (both 0.1-10 microM) was determined in CHO/hSMVT and CHO/pSPORT (control) cells. RESULTS: The absorptive transport of R.I.-K-Tat9 was passive, low (Pm approximately 1 x 10(-6) cm/sec) and not concentration dependent. R.I.K(biotin)-Tat9 permeability was 3.2-fold higher than R.I.-K-Tat9 demonstrating active (Ea = 9.1 kcal/mole), concentration dependent and saturable transport (Km = 3.3 microM). R.I.-K(biotin)-Tat9 uptake in CHO/hSMVT cells (Km = 1.0 microM) was - 500-fold greater than R.I.-K-Tat9 (at 10 microM). R.I.-K(biotin)-Tat9 transport in Caco-2 and CHO/hSMVT cells was significantly inhibited by known substrates of SMVT including biotin, biocytin, and desthiobiotin. Passive uptake of R.I.-K(biotin)-Tat9 was significantly greater than R.I.-K-Tat9 uptake in CHO/pSPORT cells. CONCLUSIONS: These results demonstrate that the structural modification of R.I.-K-Tat9 to R.I.-K(biotin)-Tat9 altered its intestinal transport pathway resulting in a significant improvement in its absorptive permeability by enhancing nonspecific passive and carrier-mediated uptake by means of SMVT. The specific interactions between R.I.-K(biotin)-Tat9 and SMVT suggest that targeting approaches utilizing transporters such as SMVT may substantially improve the oral delivery of large peptides.

Administration, Oral↗

PubMed2001

Polymorphisms in inflammatory cytokines and Fcgamma receptors in childhood chronic immune thrombocytopenic purpura: a pilot study.

Inflammatory cytokines and low-affinity Fcgamma receptor (FcgammaR) polymorphisms were investigated in 37 children with chronic immune thrombocytopenic purpura (cITP) and 218 controls. Genotype analysis included common variants in the regulatory regions of cytokines, TNF, LTA, IL1RN, IL1A, IL1B, IL4, IL6 and IL10, and structural variants of the low affinity FcgammaRs, FCGR2A, FCGR3A and FCGR3B. Associations were observed for TNF (P = 0.0032), LTA (P = 0.019), FCGR3A (P = 0.038) and FCGR3B (P = 0.0034). Two combinations of genotypes (TNF and FCGR3A; P = 0.0003, and LTA and FCGR3B; P = 0.011) were significantly associated with cITP. These results provide preliminary evidence that variant genotypes of FcgammaRs and cytokines contribute to cITP pathogenesis.

Case-Control Studies↗

PubMed2001

Medium-term functional benefits in children with cerebral palsy treated with botulinum toxin type A: 1-year follow-up using gross motor function measure.

One of the main goals when treating spasticity is to relieve pain and improve function. Intramuscular injection of botulinum toxin type A (BTX-A) has gained widespread acceptance in the treatment of spastic cerebral palsy. Several studies have clearly shown the short-term functional benefit of BTX-A treatment. Information is limited, however, on the efficacy of medium and long-term regimens, using repeated injection of BTX-A. The aim of the present open-label, prospective study was to evaluate functional outcome in children with spastic cerebral palsy after 1 year of treatment with BTX-A, using the Gross Motor Function Measure (GMFM) as a validated outcome measure. Patients (n=25, age 1.5--15.5 years) were treated with BTX-A for adductor spasm (n=12) or pes equinus (n=13). The local effect was evaluated using passive range of motion and modified Ashworth Scale. Apart from a significant improvement in joint mobility and reduction of spasticity compared to pretreatment values (P < 0.01), we demonstrated a significant improvement of gross motor function after 12 months of treatment, with a median gain of 6% in total and goal scores (P < 0.001). An increase in GMFM scores was particularly evident in younger and moderately impaired children (Gross Motor Function Classification System level III). Whether the observed improvement in gross motor function in children with cerebral palsy is specifically related to therapy with BTX-A or represents at least in part the natural course of motor development still needs clarification.

Adolescent↗

PubMed2001

Age-dependent myocardial reinduction of apoptosis inhibitors under VAD in heart failure.

Hemodynamic unloading using the ventricular assist device [VAD] results in partial functional recovery of failing hearts that show increased susceptibility to cardiomyocyte apoptosis. The caspase cascade is the central element of the apoptotic process in cells. We therefore tested expression shifts of left ventricular mRNA of caspases and their endogenous inhibitors from 15 patients with VAD support and successful bridging to transplantation using semiquantitative RT-PCR. Cardiac unloading was shown by the reduction in ventricular Pro-ANP mRNA under VAD. No alteration of mRNA expression under VAD could be observed for initiator caspases, for their selective inhibitors or for apoptotic signal molecules from the mitochondrial intermembrane space. Only two unselective cardiac IAPs (inhibitor of apoptosis protein) were increased under VAD with better recovery in younger patients. In conclusion, our findings indicate that successful hemodynamic unloading by VAD support causes only minor, age-dependent recovery in the expression of IAPs, while presumed alterations in antiapoptotic modulator systems upstream of the caspase cascade still remain to be identified.

Age Factors↗

PubMed2001

Ongoing blistering in a boy with congenital erosive and vesicular dermatosis healing with reticulated supple scarring.

Congenital erosive and vesicular dermatosis healing with reticulated supple scarring is a rare entity presenting in the newborn with crusted erosions and vesicles that heal relatively rapidly, forming unique reticulated scars. A 9-year-old boy presented with a diagnosis of junctional epidermolysis bullosa, but displayed this characteristic scarring pattern and very mild ongoing blistering. In addition, he had severe chronic conjunctivitis due to cicatricial alopecia of the eyelashes and lacrimal duct obstruction. He had no evidence of enamel defects or other features of junctional epidermolysis bullosa. Ultrastructural analysis of his skin biopsy specimens showed a normal dermoepidermal junction. This characteristic scarring disorder may be associated with mild ongoing blistering and must be distinguished from other congenital blistering disorders.

Blister↗