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Biomedical subjects

H Patterson

Publications and source records attributed to H Patterson.

At least 19 recordsLinked to original sources
PubMed2004

Emergency department intubation of trauma patients with undiagnosed cervical spine injury.

OBJECTIVES: Some trauma patients have an undiagnosed cervical spine injury but require immediate airway control. This paper reports an emergency department's (ED) experience with these patients. In particular, is there a worse neurological outcome? METHODS: A retrospective study over 6.5 years, based on prospectively collected data from the Royal Perth Hospital trauma registry. Patients with a cervical spine injury were identified and clinical data were abstracted. The primary outcome measure was evidence of exacerbation of cervical spine injury as a result of intubation by ED medical staff. RESULTS: 308 patients (1.9%) of the 15 747 trauma patients were intubated by ED medical staff. Thirty seven (12%) were subsequently verified to have a cervical spine injury, of which 36 were managed with orotracheal intubation. Twenty five (69%) survived to have a meaningful post-intubation neurological examination. Fourteen (56%) of these 25 patients had an unstable cervical spine injury. Ninety per cent of all ED intubations were by ED medical staff. No worsening of neurological outcomes occurred. CONCLUSIONS: Every ninth trauma patient that this ED intubates has a cervical spine injury. Intubation by ED medical staff did not worsen neurological outcome. In the controlled setting of an ED staffed by senior practitioners, patients with undiagnosed cervical spine injury can be safely intubated.

Accidents, Traffic↗
PubMed2001

Combination carboplatin and radiotherapy in the management of stage II testicular seminoma: comparison with radiotherapy treatment alone.

PURPOSE: To assess the results of treatment in 33 patients with stage IIA/B seminoma who were treated with carboplatin and radiotherapy (RT) between January 1989 and December 1996. PATIENTS AND METHODS: Thirty patients received single course single agent carboplatin (400 mg/m2 or area under curve (AUC 7), two patients received two courses carboplatin, and one patient received single course carboplatin and etoposide, all 4-6 weeks prior to infra-diaphragmatic RT. Results were retrospectively compared with those obtained for 80 patients treated from 1970 to 1998 with radiotherapy alone. RESULTS: There was minimal toxicity associated with the use of carboplatin prior to RT. With a median follow-up of 4 years (range 2-70 months) 2/33 patients treated with chemotherapy and RT have relapsed, 5-year relapse free survival (RFS) = 96.9% (95% confidence interval (CI) 72.9-99.4%), and one patient has died of progressive disease, 5-year overall survival (OS) = 96.7%. With a median follow-up of 11.2 years (range 6 months to 25.8 years) 15/80 patients treated with RT alone have relapsed, 5-year RFS = 80.7% (95% CI 70.1-87.9%), including 13/61 patients treated with infra-diaphragmatic RT, 5-year RFS = 77.9%, and 2/19 treated with additional supra-diaphragmatic RT, 5-year RFS = 89.5% (P = 0.277). Eleven out of 80 patients have died, 5-year OS = 94.7%. For stage IIA, 1/14 patients treated with chemotherapy and RT have relapsed, 5-year RFS = 92.3%, compared with 5/34 treated with infra-diaphragmatic RT alone 5-year, RFS = 84.9% (P = 0.527). For stage IIB, 1/19 patients relapsed (at 69 months) following chemotherapy and RT (5-year RFS = 100%), whereas 8/27 relapsed following infra-diaphragmatic RT alone, 5-year RFS = 69.4% (P = 0.0595). CONCLUSION: Infradiaphragmatic RT alone cures the majority of patients with stage II seminoma, but the relapse rate remains high particularly for patients with stage IIB disease. As compared with historical controls, carboplatin with RT appears to reduce the relapse rate in stage II seminoma with minimal additional toxicity and the results approach statistical significance for stage IIB patients. Confirmation would require a phase III randomized comparison.

Adult↗
PubMed1999

Avascular necrosis in patients treated with BEP chemotherapy for testicular tumours.

Avascular necrosis (AVN) is known to occur after combination chemotherapy for lymphomas and leukaemias that includes high dose corticosteroids, but it has been reported rarely in patients with solid tumours. We describe five recent cases in young men with testicular tumours (three of which were of good prognosis), who had been treated with chemotherapy using dexamethasone as an antiemetic. Dexamethasone is a low cost and effective antiemetic, but it may be responsible for inducing AVN in patients receiving chemotherapy for solid tumours. A prospective survey of the frequency of AVN is justified to quantify the extent of the problem.

Adult↗
PubMed1999

Radiotoxicity of bismuth-213 bound to membranes of monolayer and spheroid cultures of tumor cells.

Monoclonal antibody 13A to murine CD44 was used to bind the alpha-particle emitter 213Bi to cell surfaces of cultured EMT-6 or Line 1 tumor cells. Data on kinetics and saturation of binding, cell shape and nuclear size were used to calculate the absorbed dose to the nuclei. Treatment of monolayer cells with [213Bi]MAb 13A produced a classical exponential survival curve with no apparent shoulder. Microdosimetry analyses indicated that 1.4-1.7 Gy produced a 37% surviving fraction (D0). Multicellular spheroids were shown to bind [213Bi]MAb 13A mainly on the outer cell layer. Relatively small amounts of activity added to the spheroids resulted in relatively large absorbed doses. The result was that 3-6-fold less added radioisotope was necessary to kill similar fractions of cells in spheroids than in monolayer cells. These data are consistent with the interpretation that the alpha particles from a single 213Bi atom bound to one cell can penetrate and kill adjacent cells. Flow cytometry was used to sort cells originating from the periphery or from the interior of spheroids. Cells from the outside of the [213Bi]MAb 13A exposed spheroids had a lower surviving fraction per administered activity than cells from the interior. Cells were killed efficiently in spheroids up to 20-30 cells in diameter. The data support the hypothesis that alpha-particle emitters should be very efficient at killing cells in micrometastases of solid tumors.

Alpha Particles↗
PubMed1998

Head movement in normal subjects during simulated brain imaging.

OBJECTIVE: Videotape images of 30 volunteers were used to classify and measure head movements that may occur during brain imaging. METHODS: A simple videotape setup was designed to record simultaneously the lateral and vertex views of the subject's head. Volunteer subjects were positioned for brain imaging and their heads were videotaped for 2 hr. Head movement was identified and measured. RESULTS: All subjects demonstrated angular movement within the transaxial plane (rotation of the head). There was angular movement in the sagittal plane and translation of the transaxial plane. There was no movement of the coronal plane, nor was there any translational movement of the sagittal plane. CONCLUSION: The most dominant head movement was rotation. The effects of other factors such as height, weight, age, smoking habits, and caffeine and alcohol intake could not be determined with this sample size.

Adolescent↗
PubMed1995

Analysis of alternans in late potentials. Correlations between epicardial and body surface recordings.

The methodical performance of the signal-averaged electrocardiogram is strongly influenced by the beat-to-beat reproducibility of late potentials (LPs). Especially at higher heart rates, epicardial recordings from infarct regions show progressive beat-to-beat prolongations with alternating conduction block. To analyze the influence of beat-to-beat-alternans of LPs on the signal-averaging process, epicardial and body surface recordings were studied at different heart rates and extrastimulation. Epicardial and body surface recordings were obtained from dogs with 4-day postligation of the left anterior descending coronary artery (Harris model). Body surface potentials were averaged in different modes to a final noise level of 0.3 microV (rms) and digitally bandpass filtered (40-250 Hz). Modulation of the heart rate was performed by atrial or His-bundle pacing and by atrial premature extrastimulation. Pacing up to heart rates close to 180 beats/min produced no significant changes in the duration of LPs in epicardial and averaged body surface recordings; however, at higher pacing rates, considerable prolongation of LPs with different patterns in the epicardial leads was observed. In these cases, averaging of all beats revealed only a slight prolongation of LPs, as seen from the body surface. Selective averaging of beats with prolonged epicardial LPs showed the prolongation or absence of LPs, as seen in the epicardial recordings. Similar observations were made using an atrial extrastimulation technique, whereby the average of the premature beats was compared to the average of all normal sinus beats. Selective beat averaging of body surface potentials can unmask the prolongation of LPs due to atrial pacing or extrastimulation, as seen in recordings from the infarcted epicardium. The evidence of this modulation of LPs may improve the positive predictive value of the signal-averaged electrocardiogram.

Action Potentials↗
PubMed1994

Abnormalities of the p53 MDM2 and DCC genes in human leiomyosarcomas.

In this study we have screened a series of 29 primary leiomyosarcomas for abnormalities of both the p53 gene and the MDM2 gene, which encodes a p53-associated protein. SSCP (single-strand conformation polymorphism) analysis and direct sequencing of polymerase chain reaction (PCR)-amplified DNA were used to establish that 6/29 tumours possessed point mutations of the p53 gene. Using a monoclonal antibody that recognises the p53 protein in immunohistochemical staining experiments, we observed overexpression of the p53 protein in five of the six tumours containing point mutations in the p53 gene. Southern analysis of tumour DNA revealed that 2/29 tumours demonstrated amplification of the MDM2 gene. When considered together, these results indicate that alterations in both the p53 gene and MDM2 gene are important in the development of a significant minority of leiomyosarcomas. In addition, we have demonstrated a significant association between the presence of abnormalities of the p53 gene or MDM2 genes in leiomyosarcomas and a more advanced clinicopathological stage (P = 0.03). We have also examined the role of the DCC tumour-suppressor gene in the development of human soft-tissue tumours in a variety of histological types. Except for evidence of a rearrangement in a single leiomyosarcoma cell line, SK-UT-1, we have found no direct evidence to support a role for mutation of the gene in the development of human soft-tissue tumours.

Adult↗
PubMed1994

Postcopulatory, prezygotic isolation in flour beetles.

We report the existence of postmating but prezygotic reproductive isolation within flour beetles of the genus Tribolium. Specifically, when a female of either T. castaneum or T. freemani is paired simultaneously with both a conspecific and a heterospecific male, virtually all of the offspring are sired by the conspecific male. In contrast, when a female of either species is paired only with a heterospecific male, she produces near normal numbers of offspring. Mate choice experiments rule out the possibility that premating reproductive isolation accounts for this phenomenon. A number of different mechanisms could explain this phenomenon of postmating but prezygotic reproductive isolation.

Animals↗
PubMed1991

Detection of transforming genes by transfection of DNA from primary soft-tissue tumours.

A series of adult soft-tissue tumours were screened for the presence of activated oncogenes by transfecting tumour DNA into NIH3T3 mouse fibroblasts. In these studies an activated K-ras gene that contained a mutation at the second position of codon 12 (GGT----GAT) was found in a leiomyosarcoma. In addition, following transfection of DNA from a liposarcoma, we identified an activated gene that failed to hybridize to probes prepared from 10 known human oncogenes (K-ras, H-ras, N-ras, ret, met, trk, mas, dbl, raf and hst) that have previously been detected in DNA transfection experiments. BamHI-BamHI fragments of this activated gene of 3.5 and 8.5 kb were cloned from NIH3T3 secondary transfectants using a probe that detects the human alu family of highly repetitive DNA sequences. Repeat-free subclones of these BamHI fragments were used to map this gene to human chromosome 19 (p13.2-q13.3). Our studies also demonstrate that a subclone from one of the BamHI fragments detects a 3.0 kb transcript in primary and secondary transfectants.

3T3 Cells↗
PubMed1990

The submuscular aponeurotic system (SMAS): a histologic and comparative anatomy evaluation.

The submuscular aponeurotic system (SMAS) has been steeped in controversy. The goal of our anatomic study was to further clarify the existence of the SMAS. With an operating microscope, we performed dissections in 10 fresh cadaver heads (20 hemiheads) exposing the SMAS through a face lift incision. Through the operating microscope we were able to identify the SMAS and its relationship to other anatomic structures. Full-thickness longitudinal sections were obtained for routine histologic studies along various surgically relevant regions of the SMAS. In addition, dissections were accomplished with the operating microscope on 12 rhesus monkey fetuses ranging in age from a few weeks to 8 months. Data obtained from the fresh cadaver microdissections, topographic histology, and comparative anatomy revealed the presence of the SMAS as a distinct fibromuscular layer composed of the platysma muscle, parotid fascia, and fibromuscular layer covering the cheek.

Adipose Tissue↗
PubMed1990

Mutation of the p53 gene in human soft tissue sarcomas: association with abnormalities of the RB1 gene.

Soft tissue sarcomas have been examined for alterations in the p53 gene. In six sarcomas, loss or rearrangement of both alleles of this gene was detected while in a further seven sarcomas, point mutation or absence of transcription of the p53 gene was observed. Abnormalities of the p53 gene were found in several classes of soft tissue sarcoma, including leiomyosarcomas, rhabdomyosarcomas and malignant fibrous histiocytomas. Our studies also show that abnormalities of the RB1 suppressor gene and of the p53 gene frequently occur together. These results are consistent with the idea that the p53 gene is a tumour suppressor gene and indicate that coincident inactivation of more than one tumour suppressor gene may, in some cases, be required for tumour development.

Base Sequence↗
PubMed1975

Ultrastructure and adhesion properties of Ruminococcus albus.

Morphological studies have shown that cells of the anaerobic rumen bacterium Ruminococcus albus have electron-translucent granules of reserve carbohydrate in their cytoplasm, and that they have a polysaccharide "coat" layer external to their gram-negative cell wall. This coat layer, which stains specifically with ruthenium red, forms a compact mat of fibers adjacent to the cell, and fibrous elements also project as much as 0.6 mum from the cells. These radial fibers are clearly visualized by freeze-etching, and can be seen to extend throughout the extensive intercullular space in centrifuged pellets of these bacteria. Cells of R. albus adhere to cellulose fibers added to the culture medium, and the coat material is seen to mediate this adhesion in addition to its function in the general protection of these cells.

Anaerobiosis↗