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Biomedical subjects

A Roman

Publications and source records attributed to A Roman.

At least 73 records · Page 4Linked to original sources
PubMed1989

Calbindin-D28 in mammalian brain, retina, and endocrine pancreas: immunohistochemical comparison with calretinin.

Calbindin 28K and calretinin are very similar calcium binding proteins which are both present in the central nervous system (CNS). They respectively bind 4 and 5 Ca++ ions. We have compared by immunohistochemistry and in situ hybridization their localisation in the brain and the retina. The two proteins are generally expressed in different neurons with a few neurons containing both calcium binding proteins. Calbindin 28K is also present in the endocrine system. We have examined the cellular distribution of calbindin in the pancreatic endocrine cells of chick, rat and human and found variable distribution among the different endocrine cell types. We also describe the presence of calbindin in RINm5F cells, an insulin-producing tumor cell line derived from a radiation-induced rat insulinoma.

Animals↗
PubMed1989

Human papillomaviruses: are we ready to type?

The issue of determining which human papillomavirus (HPV) is present in a clinical specimen (typing specimens for HPVs) is receiving attention because HPVs cause condyloma acuminata and are associated with the continuum of disease which ranges from dysplasia to invasive genital cancer. Morphological inspection of precancerous lesions is not sufficient to determine which lesions will progress and which will not. A number of research tools based primarily on deoxyribonucleic acid hybridization have been developed. These permit identification and typing of HPV in genital tract scrapings or biopsies. Some HPV types (e.g., HPV-16 and HPV-18) have been identified in high-grade dysplasias and carcinomas more commonly than other types (e.g., HPV-6) and have been designated "high risk" types for cervical cancer. Thus, the question arises whether HPV typing would improve patient management by providing increased sensitivity for detection of patients at risk or by providing a prognostic indicator. In this review, the available typing methods are reviewed from the standpoint of their sensitivity, specificity, and ease of application to large-scale screening programs. Data implicating HPVs in the genesis of genital tract cancers are reviewed, as is the association of specific HPV types with specific outcomes. We conclude that there is currently no simple, inexpensive assay for HPV types, although such assays may be developed in the future. Analysis of the typing data indicates that, while HPV types can be designated high risk and low risk, these designations are not absolute and thus the low-risk group should not be ignored. In addition, interpretation of the data is complicated by finding high-risk types in individuals with no indication of disease. Insufficient data exist to indicate whether knowledge of the presence of a given HPV type is a better prognostic indicator than cytological or histological results. Thus, more research is needed before it can be determined whether typing information will augment the method currently in use for deciding treatment regimen and whether it warrants widespread use.

DNA Probes, HPV↗
PubMed1989

Impaired non-specific delayed cutaneous hypersensitivity in bird fancier's lung.

The relation between non-specific delayed cutaneous hypersensitivity and bird fancier's lung was investigated in 13 patients with the disorder. They were compared with 50 subjects who had no reason to have decreased non-specific delayed cutaneous hypersensitivity (control group) and 34 patients with pulmonary sarcoidosis. In addition, 13 patients with bird fancier's lung (11 of the original group) were tested at least one year after avoiding exposure to the causal antigen. Five antigens (candidine, staphylococcal toxoid, tuberculin purified protein derivative, trichophyton, and streptokinase-streptodornase) were injected intradermally (0.1 ml) and the mean weal diameter was measured at 48 hours. The mean weal size was significantly less in the subjects with bird fancier's lung at the time of diagnosis than in the control group (2.23 v 5.66 mm) but did not differ significantly from that of the subjects with sarcoidosis (2.80 mm) or from that of the bird fanciers with no exposure to the causal antigen for one year (2.75 mm). The impairment of non-specific delayed cutaneous hypersensitivity in patients with bird fancier's lung appears to be quantitatively similar to that occurring in sarcoidosis.

Adult↗
PubMed1989

Surgical treatment of bone metastases of the peripheral skeleton--a review of 33 cases.

Out of a total of 31 patients (26 females and five males) there were 24 complete and nine impending pathological fractures. These, treated from October 1985 to September 1987 at the Bordet Institute, were evaluated. Breast cancer was the most frequent underlying disease (66%) followed by lung cancer (12%). Eighteen lesions were treated by endoprosthetic replacement and 15 by an intramedullary fixation device. Bone cement was added to either of these. Satisfactory pain relief was obtained in 82% of the treated areas and restoration of function in 76%. Complications were rare but included one easily resolved superficial wound infection, four deep venous thromboses, movement limited to 21% (seven joints), and the changing of two fixation or reconstruction devices. Median survival time was 6 months; 35% of the patients were still alive after 12 months and 10% after 24 months.

Adult↗
PubMed1989

The FDA rhesus breeding colony at La Parguera, Puerto Rico.

Experiences of the Caribbean Primate Research Center (CPRC) with the Food and Drug Administration's (FDA) rhesus monkey breeding contract at La Parguera and lessons which should have been learned are discussed. Onset of the rainy season and timing of rhesus monkey conceptions for 1973-79 showed random association. Electrocardiographic recordings of a male rhesus monkey during reproductive activity indicated extremely high and highly variable heart rates following ejaculation.

Academies and Institutes↗
PubMed1988

Pineal-retinal molecular relationships; immunocytochemical evidence of calbindin-27 kDa in pineal transducers.

Calbindin-27 kDa immunocytochemical localization was studied concurrently in the pineal organ and retina from human as well as representatives of all vertebrate classes. Calbindin immunoreactivity was demonstrated in retinal cones (but not in rods) and in pineal transducers (cone-like and modified photoreceptor cells, pinealocytes) of a majority of amniotes. In contrast, no labelling was observed in anamniotes, except in retinal cones of the toad. Labelling was distributed through all cellular compartments (outer and inner segments, perikarya, pedicles or processes) of pineal transducers and retinal cones. Intra- and interspecific variations of calbindin contents are discussed.

Animals↗
PubMed1988

Characterization of human papillomavirus type 6b DNA isolated from an invasive squamous carcinoma of the vulva.

Human papillomavirus type 6 (HPV 6) DNA was detected in an episomal form in DNA extracted from an invasive squamous carcinoma of the vulva. The viral DNA, designated HPV6-T70, was molecularly cloned. Restriction analysis of the HPV6-T70 genome revealed an insertion of approximately 35 bp in the 5' portion of the upstream regulatory region relative to the prototype HPV 6b genome, cloned from a benign genital wart (E.-M. de Villiers, L. Gissmann, and H. zur Hausen, 1981, J. Virol. 40, 932-935). However, sequence analysis of the upstream regulatory region identified several alterations in the purine-thymidine-rich region spanning nucleotides 7292-7400. One insertion of 24 bp at position 7323 represented an exact tandem duplication of nucleotides 7300-7323. A second insertion of 58 bp at position 7350 had 84% positional identity to immediately adjacent HPV 6 sequences (nucleotides 7303-7356) and was also similar to the 74-bp insertion found at position 7348 in HPV-6vc, cloned from an invasive verrucous carcinoma of the vulva (R. F. Rando, D. E. Groff, J. G. Chirikjian, and W. D. Lancaster, 1986, J. Virol. 57, 353-356). A deletion of 49 bp (nucleotides 7351-7399) immediately followed the 58-bp insertion. The cloned HPV6-T70 DNA induced the morphological transformation of NIH 3T3 cells.

Animals↗
PubMed1988

Alterations in the regulatory region of the human papillomavirus type 6 genome are generated during propagation in Escherichia coli.

We analyzed the long control regions (LCRs) of seven human papillomavirus type 6b (HPV-6b) clones, which contained prototype HPV-6b sequences recloned into various plasmid vectors and propagated in different strains of Escherichia coli. Southern blot analysis and DNA sequencing demonstrated three different sequences, each distinct from the published prototype HPV-6b sequence. Two of the plasmids contained insertions of 24 and 94 base pairs (bp) and a 1-bp deletion. Four plasmids contained insertions of 24 and 58 bp and a deletion of 49 bp. One plasmid contained a single insertion of 77 bp. The 94-, and 58-bp insertions occurred at the same site and had 100% positional identity across their shared lengths. All changes were located in the purine-thymidine-rich region of the LCR (nucleotides 7292 to 7400). Two additional LCR sequences were detected by restriction analysis of two other HPV-6b clones. We conclude that the purine-thymidine-rich region of the LCR is a hot spot for recombination in E. coli and that the alterations are the result of recA-independent events. These results emphasize the need to rigorously prove that a cloned isolate is an authentic copy of the genomic DNA present in the original lesion. In addition, the data indicate that the HPV-6b LCR sequences employed in different laboratories may be different, even if their parental DNAs were identical. Finally, we discuss the need for caution in assigning biological significance to alterations in this region, in view of the limited data available on the true identity of the HPV-6b LCR.

Base Sequence↗
PubMed1987

Transcriptional regulation of the human papillomavirus-16 E6-E7 promoter by a keratinocyte-dependent enhancer, and by viral E2 trans-activator and repressor gene products: implications for cervical carcinogenesis.

The transcriptional promoter of the candidate E6-E7 transforming gene region of human papillomavirus (HPV)-16 (P97) was active in transiently transfected cervical carcinoma cells when linked to the HSV-1 tk or bacterial cat genes. Sequences 5' to P97 contain a short enhancer element responding to cellular factor(s) in uninfected human foreskin keratinocytes and in cervical carcinoma cells, but not in human or animal fibroblasts. The E2 trans-activator products of HPV-16 or of the related bovine papillomavirus (BPV)-1 further elevated HPV-16-driven transcripts in co-transfections, and required the presence of E2-binding ACC(N)6GGT cores in cis. A 'short E2' C-terminal repressor gene product (sE2) of HPV-16 or the BPV-1 sE2 repressor not only inhibited viral E2 trans-activation, but also suppressed enhancer response to keratinocytic factors. Suppression by the sE2 products was abolished by deletion of the E2-binding cores in cis or by a mutation in the sE2 DNA binding domain. The keratinocyte-dependent enhancer is likely to contribute to the epithelial cell tropism of HPV-16, and may direct persistent E6-E7 gene transcription in response to cellular factors in cervical carcinoma cells in which the viral E2 genes are inactive.

Animals↗
PubMed1987

Expression of human papillomavirus type 6 E1, E2, L1 and L2 open reading frames in Escherichia coli.

Open reading frame (ORF) fragments (putative gene fragments) from human papillomavirus type 6b (HPV-6b) were inserted into the bacterial expression vector pHK413 to provide viral antigenic determinants. Approximately 86% of the entire L1 ORF, 82% of the E2 ORF, and 52% of the L2 ORF were expressed in Escherichia coli. The E1 ORF was cloned as two fragments. The constructions containing E1n (coding for the N-terminal region) and E1c (coding for the C-terminal region) expressed 27% and 16% of the E1 ORF, respectively. Protein encoded by the L1 ORF, but not that encoded by the L2 ORF, reacted with antibodies elicited by disrupted bovine papillomavirus. These reagents will be extremely useful in unravelling the HPV-6b replication cycle.

Antigens, Viral↗
PubMed1987

Role of the agnoprotein in regulation of simian virus 40 replication and maturation pathways.

Analysis of two agnogene mutants, dl2304 deleted over the entire agnogene and in2379 carrying a 2-base insert, indicated that the mutant phenotype of small plaque formation must be the result of a defect late in the maturation pathway. Both mutants were removed from the pool of molecules available for replication with wild-type kinetics. Whereas dl2304 was somewhat reduced in its rate of progression from chromatin to previrions-virions, in2379, which produced even smaller plaques than dl2304 did, progressed with wild-type kinetics. Therefore, the agnoprotein was not required for progression from chromatin to previrions.

Chromatin↗
PubMed1987

Human papillomavirus deoxyribonucleic acid in lesions of the female genital tract: evidence for type 6/11 in squamous carcinoma of the vulva.

Tissue specimens from 51 patients with genital condyloma acuminata or invasive cervical or vulvar carcinomas were analyzed for the presence of human papillomavirus deoxyribonucleic acid (DNA) using the dot blot technique. Of ten condylomas, 80% contained DNA related to human papillomavirus 6 or 11. Sixty percent had evidence of DNA related to human papillomavirus 16, and 30% contained DNA related to human papillomavirus 18. Of 24 squamous cervical carcinomas, 58% had human papillomavirus type 16-related DNA, 33% had type 6- or 11-related DNA, and 4% had type 18-related DNA. Nine primary or recurrent vulvar carcinomas were analyzed. Seventy-eight percent contained human papillomavirus type 6- or 11-related DNA, 33% type 16-related DNA, and 22% type 18-related DNA. Whereas invasive cervical carcinomas predominantly contained DNA related to human papillomavirus 16 or 18, invasive vulvar carcinomas predominantly contained DNA related to types 6 or 11. Thus, human papillomavirus type alone cannot distinguish benign from malignant epithelial disease in the female genital tract.

Adult↗
PubMed1986

Human papillomavirus DNA associated with foreskins of normal newborns.

Foreskins from 70 unselected infants undergoing routine circumcision were analyzed by dot blot hybridization for the presence of DNA related to that of human papillomavirus (HPV) type 6, 11, 16, or 18. Three foreskins (4%) contained HPV DNA; two contained DNA related to HPV-16, and one contained DNA related to HPV-6. These results suggest that neonates exhibit evidence of a relatively high incidence of exposure to HPV. The outcome of exposure may be initially asymptomatic. A retrospective study of maternal charts showed six mothers with abnormal Pap smears, but no correlation could be identified between these mothers and the HPV-positive foreskins.

Adolescent↗
PubMed1985

Effect of pinealectomy and circadian rhythm on avoidance behavior in the male rat.

Male adult albino rats were divided into six groups: two pinealectomized (Px); two sham-operated (Sh) and two serving as controls (C). Half of these groups were studied in daylight and the other half at night. The animals were open-field tested and then conditioned by the avoidance behavior test in the appropriate light period. No differences were observed among the groups when they were conditioned in the dark; however, the Px were conditioned significantly more rapidly than Sh or C in daylight. Intragroup comparisons between night/day conditioning showed them to be similar in Px but more rapid at night in both Sh and C. The Sh group is unique and not comparable to controls.

Animals↗
PubMed1985

A cis-acting sequence promotes removal of simian virus 40 DNA from the replication pool.

Pulse-labeled simian virus 40 (SV40) DNA is removed from the pool of molecules available for replication (i.e., it ceases to reenter replication) a few hours after synthesis. We studied this cessation of reentry with mutants containing different deletions in the structural genes of SV40. The DNAs of two independent deletion mutants, dl-1007 (24% deletion) and dl-1003 (8% deletion), were used as templates for further DNA synthesis (i.e., they reentered replication) to a greater extent than was wild-type DNA. The alteration in reentry kinetics was not because the DNAs were smaller; other deletion mutations that were from 76 to 85% of the length of wild-type DNA (dl-BE and dl-1133 with a deletion in the late region and F8dl with a deletion in the early region) did not reenter replication to a greater extent than the wild type did. Cotransfection experiments showed that the mutant phenotypes of dl-1007 and dl-1003 were poorly complemented, if at all, by the wild type. Thus, we propose that there is a cis-acting sequence located in the HindIII E fragment of SV40, not present in either of these mutants, that promotes the efficient removal of DNA from the replication pathway.

Animals↗
PubMed1985

Occupational low-back pain in hospital nurses.

A survey of hospital staff nurses of a large tertiary care hospital was performed to investigate occupational low-back pain. Attack rates of 41% (37% "occupational") and 52% (occupational) were found using recall periods of two weeks and six months, respectively. Comparison with a control group suggests the validity of the work-relatedness of low-back pain in nurses. Factors associated with the disorder were also investigated, with results showing no differences due to nursing division assignment but significant association with specific tasks.

Adult↗