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Biomedical subjects

R J Harris

Publications and source records attributed to R J Harris.

17 recordsLinked to original sources
PubMed1992

O-linked fucose is present in the first epidermal growth factor domain of factor XII but not protein C.

Epidermal growth factor (EGF) domains are found in many proteins, particularly those of the coagulation/fibrinolytic system. We and others have demonstrated that tissue plasminogen activator (t-PA) and prourokinase are modified by the attachment of fucose to equivalent threonine residues within their EGF domains. Factor XII and protein C each contain two EGF domains; in both proteins, the EGF domain nearest the N terminus has a threonine residue in a position homologous to that which is fucosylated in t-PA. In protein C, this site is 3 residues from the position of another post-translational modification, beta-hydroxylation of Asp-71. We isolated peptides containing these sites to determine, primarily by mass spectrometric analysis, the presence of O-linked fucose and/or beta-hydroxyaspartate. We found that factor XII is fully fucosylated at Thr-90. Protein C is unmodified at the equivalent site (Thr-68) and is completely beta-hydroxylated at Asp-71. It has been recently reported that the first EGF domain of human factor VII has O-linked fucose at the equivalent position (Ser-60) (Bjoern, S., Foster, D. C., Thim, L., Wiberg, F. C., Christensen, M., Komiyama, Y., Pedersen, A. H., and Kisiel, W. (1991) J. Biol. Chem. 266, 11051-11057), while it is unmodified at Asp-63 despite having the consensus sequence for beta-hydroxylation at the latter site. These observations raise the possibility that O-linked fucosylation and beta-hydroxylation of EGF domains are mutually exclusive post-translational modifications.

Amino Acid Sequence↗
PubMed1992

Laboratory diagnosis of Mycoplasma pneumoniae infection. 4. Antigen capture and PCR-gene amplification for detection of the Mycoplasma: problems of clinical correlation.

Direct detection assays for Mycoplasma pneumoniae were established by PCR amplification of short sequences within the foot protein/adhesin (P1) gene and the 16S ribosomal RNA gene. Specificity and sensitivity was excellent, no hybridization was observed with M. genitalium and other human Mycoplasma species. In nose and throat washings from subjects with respiratory infection a pattern of high counts (c.f.u./ml) of M. pneumoniae (deduced from the amount of amplified PCR product), and a positive antigen capture assay, was found in 83% of subjects with serological evidence of current infection with M. pneumoniae. A small proportion of subjects with serological patterns suggesting infection in the more distant past had positive PCR assays. This was considered to represent either persistence of the organism from a previous infection or perhaps transient carriage during a reinfection, without substantial change in antibody response. PCR-based assay of M. pneumoniae offers a powerful, rapid, and sensitive substitute for culture of the mycoplasma. Antigen capture, while less sensitive than PCR, offers the advantage that it is more often positive with samples from current infection and requires less stringent laboratory organization to contain false positive results. We conclude however that the laboratory diagnosis of a chosen clinical episode should not rest on the PCR or Ag-EIA assays alone, but must also include antibody assays to confirm whether infection is current or represents persistence from past exposure.

Antigens, Bacterial↗
PubMed1992

Rapid detection of respiratory syncytial virus in nasopharyngeal aspirates by reverse transcription and polymerase chain reaction amplification.

A rapid method for detection of respiratory syncytial virus (RSV) in nasopharyngeal aspirates, involving a combination of reverse transcription and polymerase chain reaction amplification (RT-PCR), has been developed. The RT-PCR assay employs oligonucleotide primers specific for the region of the RSV genome which encodes the F1 subunit of the fusion (F) glycoprotein. Other respiratory viruses do not give a positive reaction. The RT-PCR assay was tested on 202 nasopharyngeal aspirates collected from children with clinical signs of respiratory infection, and the results from RT-PCR were compared with those obtained from virus culture and direct detection by enzyme immunoassay (EIA). RT-PCR results were positive in 118 of 125 samples from which RSV was cultured, as well as in 4 of 7 samples which were culture negative but EIA positive. RT-PCR results were negative in 68 of 70 culture-negative, EIA-negative samples, which included 11 samples from which other respiratory viruses were isolated. The speed, sensitivity (94.6%), and specificity (greater than 97%) of the RT-PCR assay suggest that this technique could be useful for rapid detection of RSV in clinical samples.

Base Sequence↗
PubMed1992

The connective tissue and partial thickness double pedicle graft: a predictable method of obtaining root coverage.

Obtaining predictable root coverage has been a goal of periodontal therapy for sometime. The purpose of this study is to present a technique for obtaining root coverage. This study reports the results of 20 patients (30 defects) treated with a connective tissue and partial thickness double pedicle graft. Root coverage of 100% was obtained in 24 of 30 defects, or 80% of the time. In all the treated defects the root coverage obtained was to within 0.5 mm of the cemento-enamel junction. The mean percent root coverage was 97.4%. The mean amount of exposed root surface initially was 3.6 mm. At the final postoperative appointment the mean exposed root surface was 0.1 mm. This change represents a net root coverage of 3.5 mm or 97.2%. The number of sites with bleeding on probing and plaque present decreased. The esthetics, both color match and tissue contours, were acceptable to all the patients in all cases. With this technique root coverage can be accomplished in a predictable manner.

Adolescent↗
PubMed1991

Tissue plasminogen activator has an O-linked fucose attached to threonine-61 in the epidermal growth factor domain.

An unusual type of glycosylation has been observed for tissue plasminogen activator (t-PA). The monosaccharide fucose is glycosidically linked to threonine-61 in the epidermal growth factor region of t-PA. The presence of O-linked fucose was demonstrated by carbohydrate analysis and mass spectrometry of tryptic and chymotryptic peptides that contain this site. The susceptibility of the fucose residue to alpha-fucosidase indicated that it was in the alpha-anomeric configuration. Fucosylation of threonine-61 was observed in t-PA isolated from the Bowes melanoma cell line and from recombinant expression systems using Chinese hamster ovary or human embryonic kidney cells. Fucosylation of the homologous residue in prourokinase has also been reported recently. Our results indicate that this novel type of glycosylation may be common to the epidermal growth factor domains found in coagulation and fibrinolytic proteins and, therefore, suggest that the modification may have functional significance.

Amino Acid Sequence↗
PubMed1991

Laparoscopic appendectomy for acute appendicitis: indications and current use.

Laparoscopic evaluation was performed in 43 consecutive patients with right lower abdominal pain and preoperative diagnosis of possible appendicitis. Patients with generalized peritonitis and evidence of perforation of the appendix were not considered for laparoscopy. Visualization was sufficient for making a diagnosis in 97.7% of the cases. In 95%, laparoscopic findings were compatible with the pathology report. Thirty-five patients underwent successful laparoscopic appendectomy with neither intraoperative nor postoperative complications. No further surgery was required; slightly elevated temperatures in 6 patients responded to treatment with antibiotics, and there were no wound infections. Laparoscopic appendectomy is minimally invasive and results in less postoperative pain and morbidity and fewer adhesions and other long-term sequelae than conventional laparotomy. It is associated with superior cosmetic results, a shorter hospital stay, and faster return to normal activities. This experience suggests that if there is no evidence that the appendix is perforated or that generalized peritonitis exists and if qualified physicians and adequate facilities are available, patients presenting with right lower quadrant abdominal pain and possible appendicitis are best evaluated and treated with laparoscopic technique.

Acute Disease↗
PubMed1979

The need to be held: state or trait variable.

The need to be held has been observed to be related to various moods and personality dimensions. It is unclear, however, whether this need functions as a state or trait variable. Data were collected from 85 pregnant subjects at 4 months, 9 months, and 6 weeks postpartum. Measures of the need to be held, neuroticism, relationship with parents, self-concept and maternal attachment were used to determine whether the need to be held is a trait or state variable, as well as to explore the etiology of the need to be held. Data were analyzed by a trend analysis of repeated measures and analysis of variance. Results showed that the need to be held is a trait variable in that it did not change throughout pregnancy and is related to the predisposition of depression. The etiology of the need to be held remains open for investigation.

Adult↗
PubMed1978

Multiple antibiotic allergies.

A case of an 18-year-old woman with postoperative infectious complications and multiple antibiotic allergies is discussed. The case poses several problems: the selection of an appropriate antibiotic to combat the infection, the persistence of the infection, and the treatment of multiple allergic responses to each of the antibiotic agents chosen.

Adolescent↗
PubMed1977

Mandibular prognathism and apertognathia associated with cleidocranial dysostosis in a father and son.

No reports to date have described apertognathia as an associated finding of cleidocranial dysostosis. The case of a patient with prognathism and apertognathia associated with cleidocranial dysostosis is reported. Periodontal, restorative, prosthetic, and oral surgical services were necessary to rehabilitate this patient orofacially. A review of the syndrome and of the patient's familial history is presented.

Adult↗
PubMed1977

Myxoma of the maxilla: report of case.

A review of the literature and a report of a case of myxoma of the maxilla in a 1-year-old Negro girl have been presented. This case is interesting because of its rarity at this age and its location. Originally, a Weber-Ferguson approach was considered. However, a transoral approach provided excellent access for complete visualization and removal of the tumor. This reinforces the advantages to the patient that result from the cooperation of different surgical services.

Female↗
PubMed1975

Spontaneous and chemically induced transformation of rat embryo cell cultures.

The transformation of Wistar rat embryo cells in vitro has been studied in passaged cultures using two criteria for transformation: (1) the ability of cells to form colonies in soft agar and (2) the ability of cells to form tumours in young syngeneic animals. In general there was good correlation between the two criteria. Spontaneous transformation was observed in all untreated cultures by 44 weeks although, by not allowing the cells to become confluent, the tendency was for cultures to transform earlier (i.e. 15-21 weeks). It was noticeable that despite untreated cultures having been in vitro for different lengths of time, most cultures transformed after a similar number of passages (42-50). Treatment of the embryo cells with the alkylating agent nitrosomethylurea (NMU) or benzo(alpha)pyrene (BP) sometimes resulted in transformation after a shorter period in vitro than the controls (minimum 12 weeks) although some treated cultures took longer. Transformed cells produced transplantable fibrosarcomata in syngeneic hosts and those arising from NMU transformed cells were histologically different from those arising from spontaneously transformed cells. The significant of spontaneous transformation in in vitro rat cell transformation systems is discussed.

Animals↗
PubMed1975

Forecasting patient tray census for hospital food service.

Five computerized forecasting models were tested with data on daily patient tray demand in a large medical center food service, and results were compared with intuitive forecasts made by the food service supervisor. All five models gave more accurate results than the intuitive procedure; an adaptive exponential smoothing model was most accurate. The effects of model complexity and data storage requirements are discussed, and simple exponential smoothing is suggested for forecasting patient tray demand in this setting.

Computers↗