Retinopathy of prematurity and cortical blindness.
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Blindness↗
Biomedical subjects
D Murphy
Publications and source records attributed to D Murphy.
Oxytocin transgenic mice.
We have compared the expression patterns in transgenic mice of bovine oxytocin constructs consisting of the 0.9 kilobase pair (kbp) structural gene flanked by varying lengths of upstream and downstream sequences. Over 200 offspring were derived from fertilized one-cell mouse eggs injected with construct bOT6.5, which consists of 3 kbp of upstream sequences and 2.6 kbp of downstream sequences. However, no transgenic founders were identified. In parallel experiments with other constructs, 30% of pups carried integrated copies of the injected transgene DNA. It therefore appears that bOT6.5 is toxic to mouse embryos. As previously reported (Ang et al., 1991), bOT, consisting of 2.6 kbp of downstream sequences and 0.6 kbp of upstream sequences, was expressed in lung and in testicular Sertoli cells, but no expression was detected in the hypothalamus. bOT3.5, which consists of 0.6 kbp of upstream sequences and 1.9 kbp of downstream sequences, retains testis and lung expression, but, surprisingly, is also expressed in the hypothalamus. These data suggest that the 0.7 kbp of downstream sequences that are present in bOT, but which are absent from bOT3.5, contain elements that mediate the repression of hypothalamic expression. The activity of this repressor must be itself overcome in the normal genomic context of the bovine OT gene. Within the hypothalamus, in situ hybridisation analysis has revealed expression of bOT3.5 in the supraoptic nucleus (SON) and paraventricular nucleus (PVN), but not in the suprachiasmatic nucleus (SCN). In parallel with the response of the endogenous murine OT RNA, 7 days of salt-loading resulted in a significant increase in the level of transgene RNA in the SON. In the PVN, neither the endogenous OT RNA nor the transgene RNA responded significantly to salt-loading. Transgene RNA levels in the hypothalamus have also been shown to be elevated during late pregnancy and lactation.
Animals↗
Ectopic vasopressin expression in MMTV-Wnt-1 transgenic mice modifies mammary tumor differentiation and pathology.
A transgenic mouse model has been developed to test the involvement of ectopic neuropeptide production as a secondary factor in cancer. Mice bearing a mouse mammary tumor virus-vasopressin (MMTV-VP) fusion transgene synthesized authentic vasopressin in mammary ducts and alveoli, but this had no effect on mammary gland development and growth. Mice bearing the MMTV-VP transgene were then mated with mice bearing the MMTV-Wnt-1 transgene to produce bitransgenic animals. Two types of mammary tumor develop in MMTV-Wnt-1 mice; type A mammary adenocarcinomas are uniform with fine acinar structure composed of small epithelial cells arranged to form round cavities and elongated tubules, while adenocarcinoma type B tumors have acinar areas, cystic spaces filled with blood or fluid, intracystic papillary projections, and cords as well as sheets of cells. Compared to the MMTV-Wnt-1 mice, the bitransgenic animals developed proportionally less type B tumors. Further, type B mammary adenocarcinomas from bitransgenic mice exhibited increased proliferation and growth, as judged by mitotic index and argyrophilic nucleolar organizer region counts, compared to type B tumors from MMTV-Wnt-1 mice. These data provide evidence that ectopic neuropeptide production can modulate the development of tumors in vivo.
Adenocarcinoma↗
A testis-specific promoter in the rat vasopressin gene.
In the rat testis, the vasopressin gene is transcribed into precursor RNAs that are processed into a number of mature transcripts. One of these transcripts has a structure identical to that of the hypothalamic RNA that encodes the vasopressin prepropeptide, but is present at such low levels that it can only be detected by the polymerase chain reaction. Other vasopressin-like RNAs are derived from differential splicing events that join transcribed sequences between 3 and 9 kilobases upstream of the hypothalamic transcription start site to exons corresponding to II and III of the hypothalamic-type RNA. Here we describe the sequence of a testis-specific promoter and the exon structure of its transcription unit. We show that an in vitro synthesized RNA corresponding to the longer testicular vasopressin gene-derived transcript is not able to act as a template for protein synthesis in two different cell-free lysates. As attempts to localize the vasopressin-gene derived RNAs to particular cell types in the testis by in situ hybridization have consistently failed, we have used indirect methods. Three different procedures were used to effect germ cell depletion in adult male rats. Acute heat treatment of the testis, chronic ingestion of hydroxyurea, and chronic vitamin A deficiency all reduced the level of the aberrant testicular vasopressin-gene derived RNAs, indicating that their expression is closely associated with the integrity of germ cells and ongoing spermatogenesis.
Animals↗
A human cDNA coding for the Leydig insulin-like peptide (Ley I-L).
cDNA clones for the human Leydig insulin-like peptide (Ley I-L) have been isolated and characterized. The nucleotide sequence of the 743-bp cDNA includes an incomplete 7-bp 5'-noncoding region, an open reading frame of 393 bp, and a 343-bp 3'-noncoding region. By primer extension analysis, the transcription start site was determined as being 14-bp upstream of the translation start site. The underlying gene is expressed in the testis but not in other organs. From the cDNA sequence, it can be deduced that the Ley I-L protein is synthesized as a 131-amino-acid (aa) preproprotein and that it contains a 24-aa signal peptide. Comparison of the pro Ley I-L protein with members of the insulin-like hormone superfamily predicts that the biologically active hormone, after proteolytic processing of the C peptide, consists of a 31-aa long B chain and a 26-aa long A chain, and that it has a molecular weight of 6.25 kDa.
Amino Acid Sequence↗
Quantitative analysis of the surface morphology and textile structure of the polyurethane Vascugraft arterial prosthesis using image and statistical analyses.
The surface morphology and textile structure of the Vascugraft polyurethane arterial prosthesis were investigated. Novel methods of image analysis and the presentation of statistical data were used to obtain quantitative results of the surface morphology of the non-woven microfibrous structure of prostheses of three different sizes. These techniques have identified apparent differences in the distributions of thickness and orientation of the microfibres between the internal and external surfaces and between the three prostheses investigated.
Biocompatible Materials↗
Audit of complete axillary dissection in early breast cancer.
The role of complete axillary dissection (CAD) in the management of breast cancer is controversial and largely unresolved. Acceptance of the results of trials incorporating CAD assumes that the axillary dissection is truly complete. To address this point, and also to define quality control criteria for this operation within our unit, we audited 100 consecutive axillary dissections as follows: the primary surgeon performed what he/she felt to be a thorough CAD and submitted separately the contents of level I, II and III for pathological evaluation; a second surgeon then independently assessed the dissection and arbitrarily labelled any further excised tissue as level IV. Level IV nodes were retrieved in 38% of cases. Tumour involvement of level IV nodes was noted in 5% (2/38) of dissections where lymph nodes were retrieved, but in neither instance was pathological staging altered. There was a significant decrease in the incidence of level IV node retrieval from 47% (28/60) in the first 6 months of audit to 20% (8/40) subsequently. This novel approach to our continuing audit identified quality control criteria for this procedure in our unit and suggested that audit of this kind benefits training.
Breast Neoplasms↗
Immunohistochemical detection of mutant p53 protein in epithelial ovarian cancer using polyclonal antibody CMI: correlation with histopathology and clinical features.
Approximately 30-50% of cases of ovarian adenocarcinoma harbour mutations in the p53 tumour-suppressor gene associated with elevated levels of the protein detected by immunohistochemical staining. To investigate any relation between the presence of mutant p53 and clinicopathological features of disease, we examined a series of 50 cases of epithelial ovarian adenocarcinoma for expression of p53 by immunohistological staining on fixed, paraffin-embedded tissue sections using the polyclonal antibody CM1, and by direct nucleotide sequencing of polymerase chain reaction-amplified DNA from selected cases. Of the 50 cases examined, 28 (56%) were p53 positive and there was no significant correlation between p53 status and differentiation stage, clinical (FIGO) stage, multidrug resistance (mdr-1 P-glycoprotein) expression or response to treatment. However, we observed a statistically significant difference between the high prevalence of p53-positive serous tumours (18 out of 23) and the lower prevalence of p53-positive cases in mucinous tumours (3 of 12) suggesting that factors related to disease aetiology, associated with these histological subtypes, may determine the prevalence of functional inactivation of the p53 tumour-suppressor gene in ovarian adenocarcinoma.
Base Sequence↗
Efficient and rapid affinity purification of proteins using recombinant fusion proteases.
In the affinity purification of recombinant fusion proteins, the rate-limiting step is usually the efficient proteolytic cleavage and removal of the affinity tail and the protease from the purified recombinant protein. We have developed a rapid, convenient and efficient method of affinity purification which can overcome this limitation. In one example of the method, the protease 3C from a picornavirus (3Cpro), which cleaves specific sequences containing a minimum of 6-7 amino acids, has been expressed as a fusion with glutathione S-transferase. The resultant recombinant 'fusion protease' cleaves fusion proteins bearing (from the amino-terminus) the same affinity tail as the fusion protease, a 3Cpro cleavage recognition site, and the recombinant protein of interest. The recombinant protein is purified in a single chromatographic step which removes both the affinity tail and the fusion protease. The advantages over existing methods include much improved specificity of proteolytic cleavage, complete removal of the protease and the affinity tail in one step, and the option of adding any desired amount of fusion protease to ensure efficient cleavage. The potential flexibility of the method is shown by the use of various affinity tails and alternative fusion proteases.
3C Viral Proteases↗
Historical and contemporary correlates of syphilis and cancer.
BACKGROUND: This study examined the relationship between antecedent syphilis infection and cancer incidence in an attempt to identify specific cancer patterns. METHODS: The study cohort consisted of 16,420 people diagnosed with syphilis between 1972 and 1987 and who were residents of New York State, exclusive of New York City, at time of diagnosis. Incident cancers among cohort members were identified through linkage with files maintained by the New York State Cancer Registry. RESULTS: A total of 350 cancer cases were diagnosed among cohort members. For males and females combined, incidence was significantly elevated for cancers of the oral cavity standardized incidence ratio (SIR = 169, 95% confidence interval [CI]: 109-249), and specifically for cancer of the tongue (SIR = 251, 95% CI: 108-494). Significantly elevated incidence was observed among males for Kaposi's sarcoma (SIR = 2000, 95% CI: 1290-2950). CONCLUSION: While no conclusions may be reached concerning causality, the data do argue for increased cancer surveillance among people with syphilis. Moreover, findings are discussed in light of historical considerations.
Adolescent↗
Use of the 5' noncoding region for genotyping hepatitis C virus.
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Base Sequence↗
Mechanical lithotripsy.
Endoscopic lithotripsy is a procedure used for the removal of large stones in the common bile duct that cannot be removed after sphincterotomy. This procedure causes fragmentation of large stones, which allows easier retrieval of stones by other instruments such as balloons or baskets. There are currently two types of mechanical lithotripsy: one type uses an instrument called a mechanical lithotriptor, and the second type uses an electrohydraulic lithotriptor. This article focuses on mechanical lithotripsy. Since it is vital for the operator of this equipment to understand its function, assembly, disassembly, and maintenance, specific guidelines are provided.
Gallstones↗
Cell specific expression of a vasopressin transgene in rats.
A transgene consisting of the rat vasopressin structural gene containing a reporter in exon III, flanked by 5 kb of upstream and 3 kb of downstream sequences, is expressed in vasopressinergic, but not oxytocinergic, magnocellular neurons of rats. Functionally appropriate physiological stimuli increase transgene expression in magnocellular neurons in an exaggerated fashion; the magnitude of the transgene response to osmotic challenge exceeds that of the endogenous gene by 10-15 fold. Magnocellular vasopressinergic neurons in the rat are now accessible to rational and precise genetic perturbation of function and regulation.
Animals↗
Hypercalcaemia due to squamous cell carcinoma in a tuberculous kidney: case report and review of pathogenesis.
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Aged↗
The evidence for increasing cytotoxic dose intensity in the treatment of advanced ovarian cancer.
There is a body of conflicting evidence regarding the place of dose intense chemotherapy for advanced ovarian cancer. It remains unproven whether dose intensity is more important than total dose delivered, and measures of drug delivery to the tumour itself are absent or crude. There are various methods under evaluation for reducing the toxicity of chemotherapeutic drugs, thus enabling larger doses to be given. However, we must not lose sight of the fact that current treatment is palliative for the majority of women, making the quality of life an important issue. The place of dose intense cytotoxic chemotherapy, for the treatment of advanced ovarian cancer, must be evaluated in large, carefully designed, prospective trials which, if possible, should include a quality of life assessment.
Antineoplastic Agents↗
Student experiential learning: a collaborative community practice project.
Theoretical and experiential learning in community assessment are essential components of the preparation of first-level community health nurses. This article describes a collaborative community practice project in which faculty incorporated senior baccalaureate community health nursing students as participants. Students assessed availability and utilization patterns of health care services in Spokane, Washington. Data derived from the survey were used by community planners in addressing issues of access to health care by low-income persons. Learning outcomes of this experiential process are described within the context of Burnard's Experiential Learning Model and community health nursing course objectives. Recommendations for design of similar experiential learning opportunities are made.
Clinical Competence↗
Community analysis: a collaborative community practice project.
Lack of access to health care is a concern in many communities. A group of representatives from health, social service, other community agencies and nursing education meet regularly to address issues in providing care to homeless, low-income, and uninsured persons in Spokane, Washington. This group's efforts has been hampered by lack of clearly identified factors that adversely affect access to care. One aspect of community analysis performed by this group used a collaborative community practice model. Community diagnoses were determined from information collected from service providers. Community health nursing faculty, as clinical specialists, can play a role in such a collaborative process.
Community Health Nursing↗