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Biomedical subjects

C Cowan

Publications and source records attributed to C Cowan.

At least 19 recordsLinked to original sources

The effect of gonadotrophic stimulation on integrin expression in the endometrium.

BACKGROUND: Despite many recent advances in IVF treatment implantation rates per embryo transfer rarely exceed 30%. Three integrins (alpha(1)beta(1),alpha(4)beta(1) and alpha(v)beta(3)) have been shown to be expressed in the endometrium in a cyclically dependent manner and are thought therefore to play a vital role in the process of implantation. METHODS: The effect of gonadotrophin stimulation on the expression of these three integrins within the endometrium was investigated by examining biopsies from oocyte donation patients and comparing them with fertile controls. RESULTS: A delay in the maturation of the glandular epithelium was found in the oocyte donation patients. There was also a reduction in the expression of all three integrins in the glandular epithelium and also a reduced expression of the alpha(v)beta(3) integrin in the luminal epithelium. CONCLUSIONS: As these integrins have been shown to be important in implantation their reduced expression after IVF treatment may have an adverse effect on pregnancy rates.

Adult↗

Outpatient ureteric procedures: a new method for retrograde ureteropyelography and ureteric stent placement.

OBJECTIVE: To evaluate a new method for retrograde ureteropyelography and retrograde ureteric stent placement. PATIENTS AND METHODS: Procedures were undertaken using a flexible cystoscope and digital C-arm fluoroscopy in outpatients under sedoanalgesia. The flexible cystoscope was used to identify the ureteric orifice and a straight 0.9 mm hydrophilic guidewire inserted and passed into the renal pelvis under fluoroscopic guidance. A 4 F general-purpose catheter was then passed over the wire and ureteropyelography performed. To place the stent the hydrophilic guidewire was exchanged for an ultra-stiff wire, over which the stent was passed directly. RESULTS: Over a 47-month period, 723 procedures were carried out in 472 patients. The clinical indications were ureteric obstruction in 229 (32%), stone disease in 165 (23%), unexplained hydronephrosis in 150 (21%), haematuria in 94 (13%) and others in 85 (12%). Of the 723 procedures, 643 (89%) were technically successful. Failure was most commonly caused by failure to cannulate the ureteric orifice (51, 7%). Just over half the procedures (366, 51%) involved stent placement or replacement. Immediate complications occurred in 17 patients (3%). Of those who were questioned, 94% (282 of 300) reported the procedure to be acceptable. CONCLUSION: Retrograde ureterography and ureteric stent placement may be satisfactorily undertaken with the patient under sedoanalgesia on an outpatient basis. This technique can reduce costs, hospital admissions, general anaesthetic use, demands on theatre time and complication rates.

Adolescent↗

Fatty acyl-CoAs inhibit retinoic acid-induced apoptosis in Hep3B cells.

Retinoic acid (RA) induces apoptosis in Hep3B human hepatoma cells. 9-Cis-RA (c-RA) had a similar effect as all-trans-RA (t-RA) in inducing cell death in Hep3B cells. RA-induced Hep3B-cell death was associated with inhibited expression of the hepatocyte nuclear factor 4 (HNF-4) gene. Palmitoyl-CoA ((C16:0)-CoA), the reported HNF-4 ligand, prevented RA-induced apoptosis. The effect of (C16:0)-CoA was specific, since palmitic acid and co-enzyme A had no effect in preventing RA-induced apoptosis. Bovine serum albumin (BSA) also prevented RA-induced apoptosis. However, in contrast to BSA, which induced cell growth, (C16:0)-CoA alone had no effect on cell growth. Investigating the possible role of HNF-4 in apoptosis, the reported HNF-4 antagonist (C18:0)-CoA was employed, and it also prevented RA-induced apoptosis. By transient transfection, overexpression of HNF-4 did not prevent RA-induced apoptosis. The induction and prevention of apoptosis caused by RA and (C16:0)-CoA were associated, respectively with the induction and inhibition of the expression of transforming growth factor beta (TGFbeta), which is known to play a role in apoptosis. Furthermore, RA and (C16:0)-CoA can regulate AP-1, which is a key regulator of the TGFbeta gene. Our data indicate that fatty acyl-CoAs can prevent RA-induced apoptosis and that TGFbeta, rather than HNF-4, may play a role in these regulatory processes. Our data also suggest that (C16:0)-CoA and (C18:0)-CoA are not the agonist and antagonist for HNF4, respectively in the Hep3B cell system.

Alitretinoin↗

A two-year-old boy with language regression and unusual social interactions.

CASE: Jimmy, a 2 1/2-year-old boy, was seen for the first time by a new pediatrician after a recent family move. His mother made the appointment for a health supervision visit although she had concerns about his language and social skills. She stated that he spoke primarily with unintelligible sounds and often communicated by pointing with his finger. He spoke only 10 words that were clear enough to be understood. Jimmy's mother said that he could hear, but she was not sure whether he understood everything she said. Although he played at home with his 4-year-old brother, he typically played by himself when he was in the presence of other children. Jimmy's mother was asked if he had had a 2-year-old visit to a pediatrician and what the assessment was at that time. She said that his delayed development was discussed with the pediatrician, but she was reassured that he would progress during the following year. An uncomplicated full-term gestation was followed by a vaginal delivery without perinatal problems. Jimmy was a "calm" baby who was breastfed for the first 6 months of life. He sat at 7 months, pulled himself up to stand with support at approximately 9 months, and walked at 13 months. Transitions were always difficult for Jimmy; he screamed and was difficult to settle whenever cared for by someone other than his parents. He typically resists physical contact when children or adults approach him. His mother recalled that language emerged early. He acquired a significant number of words between 12 and 15 months of age. Jimmy apparently recognized letters when his parents were teaching the older sibling. At 15 months, Jimmy's language output regressed dramatically, and by 18 months, he no longer used words to communicate. Since then, he has spoken fewer than 10 single words. He mostly babbles and uses repetitions of the same sounds. The pediatrician inquired into family structure and life events at the time Jimmy lost language milestones. He was told that, at this time, the father, an engineer, changed his position in the company and began to travel extensively. Jimmy's mother thought that the absence of his father might be related to the language regression. She also noted that Jimmy seemed to have a stronger attachment for his father: "Jimmy has always been attracted to his father, and his brother seems to prefer me." The parents' marriage was strong and free of any major disharmony. During the interview, the pediatrician noted that Jimmy played persistently with his set of small trains, repetitiously lining them up in order. He was not interested in other toys that were on the floor next to him. He ran around the trains, mostly on his toes, while making unintelligible sounds. He looked away when the pediatrician called his name and became agitated when his mother attempted to redirect his attention to the examination. The pediatrician, 4 years in practice after his residency, had never seen a child with Jimmy's pattern of development. That Jimmy's development was unusual in two domains was apparent to his pediatrician from the preceding information and brief observations. He asked himself what the next steps should be.

Adult↗

Invasion of epithelial cells by Yersinia pestis: evidence for a Y. pestis-specific invasin.

The causative agent of plague, Yersinia pestis, is regarded as being noninvasive for epithelial cells and lacks the major adhesins and invasins of its enteropathogenic relatives Yersinia enterocolitica and Yersinia pseudotuberculosis. However, there are studies indicating that Y. pestis invades and causes systemic infection from ingestive and aerogenic routes of infection. Accordingly, we developed a gentamicin protection assay and reexamined invasiveness of Y. pestis for HeLa cells. By optimizing this assay, we discovered that Y. pestis is highly invasive. Several factors, including the presence of fetal bovine serum, the configuration of the tissue culture plate, the temperature at which the bacteria are grown, and the presence of the plasminogen activator protease Pla-encoding plasmid pPCP1, were found to influence invasiveness strongly. Suboptimal combinations of these factors may have contributed to negative findings by previous studies attempting to demonstrate invasion by Y. pestis. Invasion of HeLa cells was strongly inhibited by cytochalasin D and modestly inhibited by colchicine, indicating strong and modest respective requirements for microfilaments and microtubules. We found no significant effect of the iron status of yersiniae or of the pigmentation locus on invasion and likewise no significant effect of the Yops regulon. However, an unidentified thermally induced property (possibly the Y. pestis-specific capsular protein Caf1) did inhibit invasiveness significantly, and the plasmid pPCP1, unique to Y. pestis, was essential for highly efficient invasion. pPCP1 encodes an invasion-promoting factor and not just an adhesin, because Y. pestis lacking this plasmid still adhered to HeLa cells. These studies have enlarged our picture of Y. pestis biology and revealed the importance of properties that are unique to Y. pestis.

Adhesins, Bacterial↗

Development and therapeutic effect of adoptively transferred T cells primed by tumor lysate-pulsed autologous dendritic cells in a patient with metastatic endometrial cancer.

We describe a 65-year-old woman with a large surgically unresectable and chemoresistant liver metastasis of endometrial carcinoma who was treated by infusion with peripheral blood T cells stimulated with tumor lysate-pulsed autologous dendritic cells (DC). Extensive in vitro characterization of the DC-activated T cells included phenotypic analysis, cytotoxicity, and intracellular cytokine secretion. High cytotoxicity was observed against autologous tumor cells, but not against NK-sensitive K562 cells, autologous Con-A lymphoblasts, or autologous Epstein-Barr virus-transformed lymphoblastoid cells. Blocking studies demonstrated that lytic activity was HLA class I restricted. Two-color flow cytometric analysis revealed that a significant proportion of CD8+ T cells was also CD56+, and analysis of intracellular IFN-gamma and IL-4 expression suggested a type 1 cytokine bias. The patient was treated by three infusions of tumor-specific T cells at 3- to 4-week intervals, and in vivo distribution of the T cells was followed by (111)In oxine labeling and serial gamma camera imaging. Tumor localization and accumulation of labeled lymphocytes was consistently detected at serial time points following each injection. However, deep infiltration of the large tumor mass by activated T cells was minimal, as evaluated in 3 dimensions by single photon emission computerized tomography (SPECT) imaging. Transient serum increases of the tumor marker lactate dehydrogenase (LDH), were detectable after each injection. Similar posttreatment elevations were seen for serum uric acid and potassium. Clinically, stabilization of the large liver metastasis was obtained during treatment. Collectively, these results indicate that tumor-specific CD8+ cytotoxic T-cell responses can be generated in patients with endometrial cancer, and suggest that T-cell immunotherapy may be of therapeutic value in patients harboring metastatic disease.

Aged↗

Development, characterization and distribution of adoptively transferred peripheral blood lymphocytes primed by human papillomavirus 18 E7--pulsed autologous dendritic cells in a patient with metastatic adenocarcinoma of the uterine cervix.

We describe a 27-year-old woman with systemic chemoresistant and radioresistant metastatic disease secondary to a recurrence of human papillomavirus (HPV) 18 infected cervical adenocarcinoma of the uterine cervix who received adoptive transfer of peripheral blood T cells stimulated with HPV 18 E7-pulsed autologous dendritic cells (DC). Extensive in vitro characterization of the DC-activated T cells derived from peripheral blood mononuclear cells (PBMC) included phenotypic analysis, cytotoxicity and intracellular cytokine production. High cytotoxicity activity was observed by CD8+T cells against autologous tumor cells, but not against NK-sensitive K562 cells, autologous Con-A lymphoblasts, or autologous Epstein-Barr virus-transformed lymphoblastoid cells. Blocking studies demonstrated that lytic activity was significantly inhibited by pretreatment of tumor targets with MAb specific for HLA class I as well as that of effector cells with anti-CD8, anti-LFA-1, but not anti CD3 MAb. Two-color flow cytometric analysis of the cytotoxic T cells revealed that a significant proportion of CD8+ cells was also CD56+. These double positive CTLs were thymically derived, as shown by expression of heterodimeric CD8 molecules (alpha/beta CD8) and were endowed with high cytotoxic activity against tumor cells. Analysis of intracellular cytokine expression showed that the striking majority of E7-pulsed DC activated CD8+ T cells strongly expressed IFN-gamma, TNF-alpha and IL-2 but not IL-4. The patient received two infusions of cytotoxic tumor-specific T cells at 2 week intervals, and in vivo distribution of the T cells was followed by 111 oxine labeling and serial gamma camera imaging. Persistent accumulation of radioactivity in the lungs, which harbored extensive metastatic disease, was detected up to 120 hrs after the infusion. Taken together, these results illustrate the potential of E7-specific and tumor-specific CTL-based immunotherapy for the treatment of patients with invasive cervical cancer.

Adenocarcinoma↗

Molecular cloning of p67, a lysosomal membrane glycoprotein from Trypanosoma brucei.

We have previously characterized a highly glycosylated membrane protein (p67) in Trypanosoma brucei spp that is apparently targeted to lysosomes in a developmentally regulated manner. Antibody to native p67 identified a partial cDNA clone from a T. b. rhodesiense expression library and RT-PCR was used to complete the sequence of the cDNA. Equal levels of p67 transcript are detected in both procyclic and bloodstream stages of the life cycle. The 2771 nt cDNA contains a 1980 nt orf encoding a 659 amino acid polypeptide (72,567 Da). Hydropathy analysis predicts a Type I membrane topology (N to C): an N-terminal signal sequence, a large hydrophilic lumenal domain with 14 N-glycosylation sites, a trans-membrane domain (19 aa), and a short (24 aa) cytoplasmic domain. Peptide microsequencing of purified p67 identified nine residues identical to the deduced amino acid sequence, confirming the identity of the cDNA and defining the signal sequence cleavage site. Antibody to p67 protein produced in E. coli recognizes the same spectrum of native p67 glycoforms as the antibody used to clone the cDNA. All features of the deduced amino acid sequence are consistent with the known properties of the native protein and suggest a structure similar to mammalian LAMPS. The cytoplasmic domain contains two putative di-leucine targeting motifs similar to those involved in lysosomal targeting in vertebrate cells. Our results suggest that a single p67 polypeptide, or a group of highly related polypeptides, is synthesized in both bloodstream and procyclic trypanosomes and that subsequent post-translational processing and lysosomal targeting is subject to stage-specific regulation.

Amino Acid Sequence↗

Subareolar versus peritumoral injection for location of the sentinel lymph node.

BACKGROUND: Sentinel lymph node (SLN) biopsy is fast becoming the standard for testing lymph node involvement in many institutions. However, questions remain as to the best method of injection. The authors hypothesized that a subareolar injection of material would drain to the same lymph node as a peritumoral injection, regardless of the location of the tumor. METHODS: To test this theory, 68 patients with 69 operable invasive breast carcinomas and clinically node-negative disease were enrolled in this single-institution Institutional Review Board-approved trial. Patients were injected with 1.0 mCi of technetium-99 sulfur colloid (unfiltered) in the subareolar area of the tumor-bearing breast. Each patient received an injection of 2 to 5 cc of isosulfan blue around the tumor. Radioactive SLNs were identified using a hand-held gamma detector probe. RESULTS: The average age of patients entered into this trial was 55.2 +/- 13.4 years. The average size of the tumors was 1.48 +/- 1.0 cm. Thirty-two percent of the patients had undergone previous excisional breast biopsies. Of the 69 lesions, 62 (89.9%) had SLNs located with the blue dye and 65 (94.2%) with the technetium. In four patients, the SLN was not located with either method. All blue SLNs were also radioactive. All located SLNs were in the axilla. Of the 62 patients in which the SLNs were located with both methods, an average of 1.5 +/- 0.7 SLNs were found per patient, of which 23.2% had metastatic disease. All four patients in which no SLN was located with either method had undergone prior excisional biopsies. CONCLUSIONS: The results of this study suggest that subareolar injection of technetium is as accurate as peritumoral injection of blue dye. Central injection is easy and avoids the necessity for image-guided injection of nonpalpable breast lesions. Finally, subareolar injection of technetium avoids the problem of overlap of the radioactive zone of diffusion of the injection site with the radioactive sentinel lymph node, particularly in medial and upper outer quadrant lesions.

Adult↗

Virulence role of V antigen of Yersinia pestis at the bacterial surface.

Yersinia pestis, the etiologic agent of plague, secretes a set of environmentally regulated, plasmid pCD1-encoded virulence proteins termed Yops and V antigen (LcrV) by a type III secretion mechanism (Ysc). LcrV is a multifunctional protein that has been shown to act at the level of secretion control by binding the Ysc inner-gate protein LcrG and to modulate the host immune response by altering cytokine production. LcrV also is essential for the unidirectional targeting of Yops to the cytosol of infected eukaryotic cells. In this study, we constructed an in-frame deletion within lcrG (DeltalcrG3) to further analyze the requirement of LcrV in Yop targeting. We confirmed the essentiality of LcrV and found that LcrG may have a facilitative role, perhaps by promoting efficient secretion of LcrV. We also constructed mutants of lcrV expressing LcrV truncated at the N or C terminus. Both the N and C termini of LcrV were required for the secretion of LcrV into the medium and targeting of Yops. LcrV was detected in punctate zones on the surface of fixed Y. pestis by laser-scanning confocal microscopy, and this localization required a functional Ysc. However, the truncated LcrV proteins were not found on the bacterial surface. Finally, we tested the ability of LcrV-specific Fab antibody fragments or full-length antibody to interfere with Yop targeting and found no interference, even though this antibody protects mice against plague. These results indicate that LcrV may function in Yop targeting at the extracellular surface of yersiniae and that the protective efficacy of LcrV-specific antibodies can be manifested without blocking Yop targeting.

Animals↗

Carcinoid tumor metastatic to the breast.

Breast metastases from nonmammary malignant neoplasms are uncommon, accounting for approximately 2% of breast tumors. There are 13 cases reported in the literature of carcinoid tumor metastatic to the breast, and more than half of these cases were misdiagnosed pathologically and treated as primary breast carcinoma, even in cases with a medical record of carcinoid tumor. We describe a patient with a history of asthma and diarrhea who presented to the University of Arkansas for Medical Sciences, Little Rock, with an exacerbation of the asthma. The results of routine physical examination revealed a mass in the left breast. A diagnosis of carcinoid tumor metastatic to the breast was made after a partial mastectomy was performed. The differential diagnosis between primary carcinoid tumor of the breast and carcinoid tumor metastatic to the breast is often controversial in surgical pathology. Diagnoses need to be made correlating clinical and histological examination in difficult cases in which there is not a diagnosis of carcinoid tumor elsewhere. Accurate diagnosis of breast metastases is important to avoid unnecessary treatment.

Aged↗

Use of touch preps for intraoperative diagnosis of sentinel lymph node metastases in breast cancer.

BACKGROUND: Intraoperative touch prep (TP) is highly accurate for determining positive breast cancer margins and thereby reducing the need for second surgeries. It also may be useful in determining the status of the sentinel lymph node (SLN) during the initial surgical resection. The objective of this study was to test the ability of intraoperative TP to predict metastatic disease and, thus, the necessity for axillary lymph node dissection (ALND) at the time of SLN biopsy. METHODS: Fifty-five patients with invasive breast cancer were entered in the SLN biopsy protocol. The SLN was identified by gamma probe, dissected, and sent to pathology for TP and permanent sections. Level I and II ALND was then performed. Any radiolabeled LN in the lymphadenectomy specimen also was sent for TP and permanent sections. RESULTS: A total of 124 radiolabeled lymph nodes (LNs) were submitted for TP; of these, 93 (75%) were SLNs. Pathologic diagnosis by TP was correct compared with permanent sections for 99.2% of the nodes. There were no false positives. There was one (0.8%) false negative. The positive predictive value was 100% and the negative predictive value was 99%. Sensitivity was 95.7% and specificity was 100%. CONCLUSIONS: TP is a simple, quick, and accurate method for detecting metastatic disease in the SLN and, when used intraoperatively, enables the surgeon to determine whether or not an ALND is necessary at the time of the initial surgery.

Adult↗

Sentinel lymph node biopsy for staging breast cancer.

BACKGROUND: Determination of axillary nodal status is essential for the staging of breast cancer since nodal status is one of the most important predictors of survival. The objective of this study was to test the hypothesis that the histology of the first draining lymph node (LN) accurately predicts the histology of the rest of the axillary LNs. METHODS: Fifty-five patients with operable invasive breast carcinoma and clinically negative axillary lymph nodes were studied. Patients were injected with Technetium-99 (99Tc) sulfur colloid around the primary tumor. A hand-held gamma detector probe was used to identify the sentinel LN (SLN). After the SLN was identified and removed, a level I and II lymphadenectomy was performed. RESULTS: The SLN was identified in 53 (96.3%) of the 55 patients entered into the trial. The sensitivity was 88.2% and the specificity was 100%. The positive predictive value was 100% and the negative predictive value was 94.6%. The accuracy of the study was 96.2%. CONCLUSIONS: The SLN biopsy for breast cancer staging is highly accurate in our hands and has the potential to decrease the morbidity and cost of managing patients with breast cancer without compromise of staging.

Adult↗

Targeting of the Yersinia pestis YopM protein into HeLa cells and intracellular trafficking to the nucleus.

The YopM virulence protein of Yersinia pestis has been described as binding human alpha-thrombin and inhibiting thrombin-induced platelet aggregation in vitro. However, recent studies have shown that a YopM-CyaA fusion protein could be targeted vectorially into eukaryotic cells through the Yersinia type III secretion system. In this study, our objective was to characterize YopM's fate in more detail. We followed YopM in the culture medium and inside infected HeLa cells. We confirmed that the native YopM is targeted into HeLa cells, where it is insensitive to exogenous trypsin. The bacteria must be surface located to target YopM, and YopB and YopD are necessary, whereas the LcrE protein (called also YopN) makes this process more efficient. Immunofluorescence localization revealed that YopM, in contrast to YopE, is not only targeted to the cytoplasm but also trafficks to the cell's nucleus by means of a vesicle-associated pathway that is strongly inhibited by brefeldin A, perturbed by monensin or bafilomycin A1 and dependent upon microtubules (decreased by colchicine and nocodazole). These findings revealed a novel interaction of Yersinia pestis with its eukaryotic host.

Bacterial Outer Membrane Proteins↗

Feasibility and applicability of coronary stent implantation with the direct brachial approach: results of a single-center study.

Implantation of stents in selected patients improves outcome after coronary angioplasty. Newer antiplatelet regimes limit access site complications associated with stenting by the percutaneous femoral approach, but a substantial proportion of patients will require anticoagulant therapy for concomitant disease or will have peripheral vascular disease that prevents access from the leg. We investigated procedural success rates and outcome in consecutive patients undergoing elective stent implantation in our institution. In 73 patients who were receiving anticoagulation therapy and were stented by a direct approach to the left brachial artery, 98.6% of stents were successfully deployed, with a major vascular access site complication rate of 1.4%. Equipment consumption, procedural success rate, and fluoroscopy time were similar in patients stented by the direct brachial or percutaneous femoral approach. Where the percutaneous femoral approach is precluded or patients are anticoagulated, stent procedures can be successfully performed by the direct brachial approach with a low rate of access site complications, even when large-caliber guiding catheters are required.

Adult↗

Personality disorders in people with learning disabilities: a community survey.

The prevalence of personality disorders has been determined by studies of both the general population and mental handicap hospitals. The present study attempts to determine the prevalence of personality disorders in a community sample and to check the implications for treatment. A community sample of learning disability service users was surveyed by obtaining a rating from a good informant to establish demographic data, level of functioning and the nature of personality disorders, if any, using the ICD-10 version of the Standardized Assessment of Personality (SAP). Fifty per cent of the sample had personality abnormalities, and 31% had sufficient impairment of the social and occupational domains and personal distress to warrant a diagnosis of personality disorder. These findings are compared with previous studies. Paranoid, schizoid, impulsive and dissocial personality abnormalities were seen to be associated with a high referral rate to psychiatric services and needed considerable therapeutic input. The prevalence of personality abnormalities in community populations with a learning disability is high. The SAP is a useful instrument for screening. This subpopulation makes significant demands on community psychiatric services.

Adult↗