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C Parker

Publications and source records attributed to C Parker.

At least 127 records · Page 7Linked to original sources
PubMed1992

Physiological evidence for the possible existence of anhydrolevuglandin E2-like activity in extracts and media from uteri of rats.

Physiological evidence is presented for the possible existence of anhydrolevuglandin E2-like activity in extracts of uteri from diestrous rats and after treatment of adult rats with estradiol and progesterone. The extracts were able to inhibit contractions in rat uterine preparations stimulated by PGE2. Uteri of vaginal Stage 3 (metestrus) were quiescent and showed decreased responsiveness to PGE2 and PGF2 alpha. These uteri showed some contractility when incubation medium from diestrous uteri (Stage 5) were transferred to them and incubation medium from them inhibited the contractility of Stage 5 uteri. When incubation media were exchanged between contractile uteri from of stages other than Stage 3, there was no change in the contraction patterns. Taken together, we believe these data indicate that AnLGE2 may be a normal constituent of the rat uterus and is physiologically increased during Stage 3 (metestrus) of the estrous cycle.

Animals↗
PubMed1992

Modulators of intracellular Ca2+ and the calmodulin inhibitor W-7 alter the expression of metastasis-associated genes MTS1 and NM23 in metastatic variants of the B16 murine melanoma.

MTS1 is a metastasis-associated gene highly expressed in highly metastatic tumours. NM23 has been described as a putative metastasis suppressor gene. Here we show that thapsigargin (which raises intracellular calcium [Ca2+]i from intracellular stores) and verapamil (which blocks Ca2+ influx) both down-regulate MTS1 and NM23 gene expression in the poorly metastatic F1 and highly metastatic ML8 variants of the B16 murine melanoma without altering their metastatic behaviour. The data presented here suggest that Ca2+ released from intracellular stores could be functionally differentiated from influxed Ca2+ and could be activating different components of the Ca2+ signalling system. Many of the cellular responses to calcium are mediated through calmodulin. We have therefore further investigated the role of Ca2+ in the regulation of the MTS1 and NM23 genes using the calmodulin inhibitor W-7. Both these genes were down-regulated after treatment of the F1 and ML8 cell variants. We have shown previously that retinoic acid reduces lung colonization by the highly metastatic variant ML8 and that melanocyte stimulating hormone (MSH) enhances lung colonization by the poorly metastatic variant F1, with corresponding changes in the relative expression of NM23 and MTS1. Here we have found that verapamil and thapsigargin have no effect on lung colonization, possibly due to both genes being down-regulated. These data support the concept that NM23 and MTS1 gene expression is linked and that metastatic potential may be determined by their relative expression.

Animals↗
PubMed1992

Dynamic clearance: mathematical assessment of flow mechanics in prostatic resection.

The understanding of flow mechanics in endoscopy is poor. In prostatic surgery, emphasis has been placed on limiting the rise of intravesical pressure with little regard to the effect on flow mechanics and visibility. A model has been developed using dynamic clearance to compare different methods of prostatic resection. The results show that in a 0.95-cm glass urethra, continuous flow irrigation has slower clearance at all flow rates when compared with intermittent irrigation and suprapubic suction. Although intravesical pressure is important, attention should also be paid to flow dynamics and more emphasis should be placed on this when new instruments and fluid delivery systems are developed.

Endoscopy↗
PubMed1992

Flow visualization in uroendoscopy: the steal effect.

Balanced continuous flow resection has been offered as the best form of irrigation in uroendoscopy. Although it will keep the bladder pressure low, using flow visualization techniques it has been demonstrated that it does not fulfil the requirements of an irrigating fluid when used in a confined environment such as the prostatic urethra. The outflowing irrigating fluid has been shown to be taken directly from the inflowing jet ('steal effect') thereby reducing the effectiveness of the irrigating jet on the working area of the resectoscope.

Endoscopes↗
PubMed1992

Blue light emission from urological equipment. Can it damage the eyes?

Blue light present in the visible spectrum at the lower wavelengths can cause damage to the retinas of monkeys and rats. In the present study the light sources and instrumentation available to the urologist were evaluated to see whether they posed a hazard. The light emitting directly from the sources, cables and telescopes was tested and these levels were found to be dangerous to the eye when compared with the safety limit recommended by the American Conference of Governmental Industrial Hygienists (ACGIH). When the light at the eyepiece of the telescopes which had been reflected off a surface was measured, the blue light levels did not appear to be harmful when compared with the ACGIH safety limit. The use of filters is discussed and the transmission of 2 types of filters shown. While the level of blue light emission from the eyepiece remains within the ACGIH level, there are no data on long-term exposure. The addition of a blue light filter may be beneficial until such time as videoendoscopy becomes the norm. The light from light sources should be protected by a shutter and more care taken with the emission from cables and telescopes.

Equipment Safety↗
PubMed1991

Communication of results of necropsies in north east Thames region.

OBJECTIVE: To evaluate the adequacy of reporting of results of necropsy to referring clinicians and to general practitioners. DESIGN: Questionnaire survey of referring clinicians and general practitioners of deceased patients in four districts in North East Thames region. Patients were selected by retrospective systematic sampling of 50 or more necropsy reports in each district. SETTING: One teaching hospital, one inner London district general hospital, and two outer London district general hospitals. PARTICIPANTS: 70 consultants and 146 general practitioners who were asked about 214 necropsy reports; coroners' reports were excluded. MAIN OUTCOME MEASURES: Time taken for dispatch of final reports after necropsy, consultants' recognition of the reports, general practitioners' recognition of the reports or of their findings, and consultants' recall of having discussed the findings with relatives. RESULTS: Only two hospitals dispatched final reports including histological findings (mean time to dispatch 144 days and 22 days respectively). 42 (60%) consultants and 83 (57%) general practitioners responded to the survey. The percentage of reports seen by consultants varied from 37% (n = 13) to 87% (n = 36); in all, only 47% (39/83) of general practitioners had been informed of the findings by any method. Consultants could recall having discussed findings with only 42% (47/112) of relatives. CONCLUSIONS: Communication of results of necropsies to hospital clinicians, general practitioners, and relatives is currently inadequate in these hospitals. IMPLICATIONS AND ACTION: A report of the macroscopic findings should be dispatched immediately after necropsy to clinicians and general practitioners; relatives should routinely be invited to discuss the necroscopic findings. One department has already altered its practice.

Autopsy↗
PubMed1991

Prognostic significance of the Karnofsky Performance Status score in patients with acute myocardial infarction: comparison with the left ventricular ejection fraction and the exercise treadmill test performance. The MILIS Study Group.

The prognostic significance of functional status has not been previously studied in the setting of acute myocardial infarction. We assessed the Karnofsky Performance Status (KPS) score, a simple functional status scale that is commonly used to categorize physical ability, in 849 patients with acute myocardial infarction who were enrolled in the Multicenter Investigation of the Limitation of Infarct Size (MILIS) study. We then compared the KPS score with other predictors of prognosis in these patients. In patients who presented with acute myocardial infarction, a lower KPS score (less than 8 on a scale of 1 to 10) 3 weeks before the index infarction was associated with a higher incidence of congestive heart failure, in-hospital cardiac arrest, and mortality during hospitalization, as compared with patients with KPS scores greater than or equal to 8 (each p less than 0.001). Cumulative 1-year and 4-year mortality rates were significantly higher in patients with KPS scores less than 8, as compared with patients with KPS scores greater than or equal to 8 (42.5% vs. 12.6% at 1 year and 61.6% vs 25.1% at 4 years, respectively; both p less than 0.001). The left ventricular ejection fraction on admission was significantly lower in patients with KPS scores less than 8, as compared with those with KPS scores greater than or equal to 8 (p less than 0.019). The cumulative mortality rate was equally well predicted by low KPS score and by left ventricular ejection fraction (both p less than 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Disability Evaluation↗
PubMed1991

Isolation and thermal stability studies of two novel serine proteinases from the fungus Tritirachium album Limber.

A number of serine proteinases are secreted into the culture medium when Tritirachium album Limber is supplied with protein as the only nitrogen source. From this population of proteinases, we have isolated two novel proteolytic enzymes, designated as proteinase R and T. We have compared the thermal stability of these two proteinases with that of subtilisin BPN' and proteinase K. Both of these proteinases were thermally stable in the absence of detergents in buffers of low (4.0) and high (10.0) pH. The thermal stability of proteinase T was not affected by the presence of 1.0% SDS either at pH 8.0 or 10.0 in contrast to proteinase R which became heat labile. At low pH, the presence of SDS was detrimental to the stability of all the proteinases.

Amino Acid Sequence↗
PubMed1991

Policy and implementation of user fees in Jamaican public hospitals.

User fees and other forms of copayment for health care are becoming of increasing interest to policymakers in developing countries. As indigenous populations continue to expand in response to current and historically high fertility, and government resources become constrained due to macroeconomic circumstances, publicly provided health care is being squeezed financially. Most developing countries have committed their governments to either providing for all health care or at least ensuring that all citizens have access to health care regardless of ability to pay. This has translated in most contexts into blanket coverage for the entire population financed and generally provided by the government. Recent periods of slow growth, high debt burdens and restricted spending on high recurrent cost sectors, such as health care under International Monetary Fund and other donor agreements have reduced many developing countries' budgets and often the real value of health expenditures. The costs of inputs (personnel, drugs and consumables), however, have not declined and quality or quantity have been necessarily reduced. At the same time, options for financial relief outside the tax system have become of increasing interest to financially constrained governments. User charges are straightforward, easily understood and can in theory be profitable in the short term. From a fairness perspective, they also charge those who actually use the health system. Their major drawback for policymakers is the potential for undermining equity in the health system.

Budgets↗
PubMed1991

Fluid delivery systems: high flow, low pressure, the key to safe resection.

The transurethral resection of the prostate (TURP) syndrome has been attributed to the effects of the excess absorption of irrigating fluid. Absorption may be reduced by preventing bladder distension using continuous irrigating resectoscopes or suprapubic trocar drainage. Pressure rises should be limited by the head of pressure in the fluid delivery systems. The flow pressure characteristics of two competing systems, Flowfusor (Kendall-McGaw) and Uromatic (Baxter), were evaluated. We have demonstrated that the Kendall-McGaw Flowfusor V4537 system provides adequate flow at a reduced head of pressure by virtue of the rigid container system and intrinsic negative pressure. The safety of TURPs is increased by reducing the risk of absorption.

Humans↗
PubMed1991

Beds or day case unit: your choice?

The aim of this study was to assess the amount of day case surgery and potential day case surgery being performed in the main theatre block of a District General Hospital, which had a thriving Day Case Unit. Our results revealed that as well as large numbers of potential day cases being performed as inpatients, many patients (both potential day cases and long-stay elective surgery patients) are spending a day(s) in hospital prior to the day of surgery. We believe that by performing all day case surgery in our Day Case Unit and by using the Day Case Unit to perform pre-admission screening on all surgical patients, a large number of bed days will become available. These beds may be used for elective or emergency admissions. Alternatively, cutting surgical beds will free monies which can be spent on the Day Case Unit.

Ambulatory Surgical Procedures↗
PubMed1991

Enhancing early breast cancer screening: an expanded role for mammography facilities is needed.

Registered mammography facilities in Connecticut were surveyed in 1988 to determine the capacity and scope of services provided to women. A total of 112 responses were analyzed. Early cancer screening service other than mammography are not routinely provided. Less than 50% of facilities offer instruction on breast self-exams or provide physical breast examinations in conjunction with mammograms. Only one in three facilities have mechanisms in place to notify women of their need for periodic screening. We conclude that efforts to expand the scope of screening services offered by mammography facilities may enhance our capacity to detect early breast cancer in women.

Breast Neoplasms↗