Biomedical subjects

R Ford

Publications and source records attributed to R Ford.

At least 37 records · Page 2Linked to original sources

PubMed2001

Measurements of the rare decay K(L) --> e(+)e(-)e(+)e(-).

We observe 441 K(L)-->e(+)e(-)e(+)e(-) candidate events with a background of 4.2 events and measure B(K(L)-->e(+)e(-)e(+)e(-)) = [3.72+/-0.18(stat)+/-0.23(syst)]x10(-8) in the KTeV/E799II experiment at Fermilab. Using the distribution of the angle between the planes of the e(+)e(-) pairs, we measure the CP parameters beta(CP) = -0.23+/-0.09(stat)+/-0.02(syst) and gamma(CP) = -0.09+/-0.09(stat)+/-0.02(syst). We also present the first detailed study of the e(+)e(-) invariant mass spectrum in this decay mode.

Journal Article↗

PubMed2001

Measurement of the branching ratio and asymmetry of the decay Xi degrees -->Sigma degrees gamma.

We have studied the rare weak radiative hyperon decay Xi degrees -->Sigma degrees gamma in the KTeV experiment at Fermilab. We have identified 4045 signal events over a background of 804 events. The dominant Xi degrees -->Lambdapi degrees decay, which was used for normalization, is the only important background source. An analysis of the acceptance of both modes yields a branching ratio of B(Xi degrees -->Sigma degrees gamma)/B(Xi degrees -->Lambdapi degrees ) = (3.34+/-0.05+/-0.09)x10(-3). By analyzing the final state decay distributions, we have also determined that the Sigma degrees emission asymmetry parameter for this decay is alpha(XiSigma) = -0.63+/-0.09.

Journal Article↗

PubMed2001

Study of the K(0)(L) --> pi(+)pi(-)gamma Direct Emission Vertex.

We have performed studies of the K(0)(L)-->pi(+)pi(-)gamma direct emission ( DE) and inner Bremsstrahlung ( IB) vertices, based on data collected by KTeV during the 1996 Fermilab fixed target run. We find a(1)/a(2) = -0.737+/-0.034 GeV2 for the DE form-factor parameter in the rho-propagator parametrization, and report on fits of the form factor to linear and quadratic functions as well. We concurrently measure gamma(K(0)(L)-->pi(+)pi(-)gamma,E(*)(gamma)>20 MeV)/gamma(K(0)(L)-->pi(+)pi(-)) = (20.8+/-0.3)x10(-3), and a K(0)(L)-->pi(+)pi(-)gamma DE/(DE+IB) branching ratio of 0.683+/-0.011.

Journal Article↗

PubMed2001

Search for the decay KL --> pi(0)e+e-.

We report on a search for the decay KL-->pi(0)e+e- carried out by the KTeV/E799 experiment at Fermilab. This decay is expected to have a significant CP violating contribution and the measurement of its branching ratio could support the Cabibbo-Kobayashi-Maskawa mechanism for CP violation or could point to new physics. Two events were observed in the 1997 data with an expected background of 1.06+/-0.41 events, and we set an upper limit B(KL-->pi(0)e+e-)<5.1 x 10(-10) at the 90% confidence level.

Journal Article↗

PubMed2001

Maintaining contact with people with severe mental illness: 5-year follow-up of assertive outreach.

BACKGROUND: Assertive outreach is a central strand of Government mental health policy in England. Are different long-term models of mental health care which include assertive outreach associated with different service user outcomes and cost? METHOD: We conducted a multi-site 5-year follow-up study of people with severe mental illness. From 0 to 18 months all three sites had Intensive Case Management (ICM) teams practising assertive outreach. From 18 to 60 months one team sustained ICM, one team merged and another was disbanded. All 131 original ICM team clients were the study participants. Outcome was measured in terms of sustained engagement with statutory mental health services, psychiatric symptoms, social functioning, resource use and cost. RESULTS: All 120 live participants were traced. Only four people had no service contact; when contacted by a researcher they appeared to be coping well. No incidents of serious violence were discovered. No differences existed between teams in the mean total symptom or total social functioning change scores at follow-up, after controlling for baseline differences. No differences existed in mean cost between teams during the first 18 months. Mean (standard deviation) annualised costs varied considerably in the 18-60 month period: sustained team Pound Sterling13,734 (10,820); integrated team Pound Sterling11,037 (13,603); disbanded team Pound Sterling5,742 (7,007) (F=4.4, 105 df, p=0.015). CONCLUSION: Continued specialist assertive outreach service models have higher costs than non-specialist services for no apparent benefit. In the long term new assertive outreach services should have procedures in place to transfer people to lower intensity and lower cost care.

Case Management↗

PubMed2001

Comparison of tissue injury between laparosonic coagulating shears and electrosurgical scissors in the sheep model.

STUDY OBJECTIVE: To compare laparosonic coagulating shears (LCS), which use ultrasonic energy, and unipolar diathermy scissors with respect to depth of tissue injury. DESIGN: Prospective observational study (Canadian Task Force classification I). SETTING: A reproduced surgical setting. SUBJECTS: An anesthetized sheep. INTERVENTION: We laparoscopically harvested uterine horn and bowel tissue. MEASUREMENTS AND MAIN RESULTS: Tissue was transected while hemostasis was maintained. Two pathologists examined tissue independently, and each was blinded as to the instrument used for harvesting. Clinical characteristics and tissue injury created by the instruments were compared. CONCLUSION: Subjectively, LCS appeared to produce less smoke plume than diathermy scissors. It also produced greater tissue damage than unipolar electrosurgery on settings of 35 W cut and 30 W coagulate.

Animals↗

PubMed2001

Laparoscopic presacral neurectomy: a review.

Dysmenorrhea can be a severe and debilitating symptom in many women. Although most women may find adequate relief of symptoms from pharmacological approaches, there remain a few with resistant pain. Presacral neurectomy, although technically challenging, may be offered after other approaches are unsuccessful. The operation is now performed increasingly by the laparoscopic approach, which has revived this operation in some centers. The anatomy, technique, and indications as well as a review of the literature supporting this operation are reviewed. The potential complications of this operation are discussed also.

Autonomic Denervation↗

PubMed2001

Deeply infiltrating endometriosis: implications, diagnosis, and management.

Deeply infiltrating endometriosis was described in the early part of the last century. Only recently, has there become a greater awareness and understanding of this form of endometriosis aided in part by advances in laparoscopic surgical technology in techniques. The clinical implications of the disease as well as diagnosis and current management are reviewed.

Endometriosis↗

PubMed2001

Laparoscopic presacral neurectomy - retrospective series.

A retrospective audit of medical records was conducted for one surgeon (AL). All patients who underwent laparoscopic presacral neurectomy for severe midline dysmenorrhoea were identified. Details of the preoperative symptoms, clinical findings and operative records were studied. Improvement of dysmenorrhoea was assessed according to a pain scale. Twelve patients who had a laparoscopic presacral neurectomy performed were identified. Eight patients reported significant improvement of symptoms, with a further two reporting mild improvement. Two patients failed to show any improvement of symptoms. We believe that the role of laparoscopic presacral neurectomy should be limited to patients with severe midline dysmenorrhoea not responding to the medical therapy. It may be a supplementary procedure to laparoscopic resection of endometriosis or adhesiolysis.

Adult↗

PubMed2001

Long-term facilitation in obstructive sleep apnea patients during NREM sleep.

Repetitive hypoxia followed by persistently increased ventilatory motor output is referred to as long-term facilitation (LTF). LTF is activated during sleep after repetitive hypoxia in snorers. We hypothesized that LTF is activated in obstructive sleep apnea (OSA) patients. Eleven subjects with OSA (apnea/hypopnea index = 43.6 +/- 18.7/h) were included. Every subject had a baseline polysomnographic study on the appropriate continuous positive airway pressure (CPAP). CPAP was retitrated to eliminate apnea/hypopnea but to maintain inspiratory flow limitation (sham night). Each subject was studied on 2 separate nights. These two studies are separated by 1 mo of optimal nasal CPAP treatment for a minimum of 4-6 h/night. The device was capable of covert pressure monitoring. During night 1 (N1), study subjects used nasal CPAP at suboptimal pressure to have significant air flow limitation (>60% breaths) without apneas/hypopneas. After stable sleep was reached, we induced brief isocapnic hypoxia [inspired O(2) fraction (FI(O(2))) = 8%] (3 min) followed by 5 min of room air. This sequence was repeated 10 times. Measurements were obtained during control, hypoxia, and at 5, 20, and 40 min of recovery for ventilation, timing (n = 11), and supraglottic pressure (n = 6). Upper airway resistance (Rua) was calculated at peak inspiratory flow. During the recovery period, there was no change in minute ventilation (99 +/- 8% of control), despite decreased Rua to 58 +/- 24% of control (P < 0.05). There was a reduction in the ratio of inspiratory time to total time for a breath (duty cycle) (0.5 to 0.45, P < 0.05) but no effect on inspiratory time. During night 2 (N2), the protocol of N1 was repeated. N2 revealed no changes compared with N1 during the recovery period. In conclusion, 1) reduced Rua in the recovery period indicates LTF of upper airway dilators; 2) lack of hyperpnea in the recovery period suggests that thoracic pump muscles do not demonstrate LTF; 3) we speculate that LTF may temporarily stabilize respiration in OSA patients after repeated apneas/hypopneas; and 4) nasal CPAP did not alter the ability of OSA patients to elicit LTF at the thoracic pump muscle.

Adult↗

PubMed2001

Xrel3 is required for head development in Xenopus laevis.

The Rel/NF-kappa B gene family encodes a large group of transcriptional activators involved in myriad differentiation events, including embryonic development. We have shown previously that Xrel3, a Xenopus Rel/NF-kappa B-related gene, is expressed in the forebrain, dorsal aspect of the mid- and hindbrain, the otocysts and notochord of neurula and larval stage embryos. Overexpression of Xrel3 causes formation of embryonic tumours. We now show that Xrel3-induced tumours and animal caps from embryos injected with Xrel3 RNA express Otx2, Shh and Gli1. Heterodimerisation of a C-terminally deleted mutant of Xrel3 with wild-type Xrel3 inhibits in vitro binding of wild-type Xrel3 to Rel/NF-kappa B consensus DNA sequences. This dominant interference mutant disrupts Shh, Gli1 and Otx2 mRNA patterning and inhibits anterior development when expressed in the dorsal side of zygotes, which is rescued by co-injecting wild-type Xrel3 mRNA. In chick development, Rel activates Shh signalling, which is required for normal limb formation; Shh, Gli1 and Otx2 encode important neural patterning elements in vertebrates. The activation of these genes in tumours by Xrel3 overexpression and the inhibition of their expression and head development by a dominant interference mutant of Xrel3 indicates that Rel/NF-kappa B is required for activation of these genes and for anterior neural patterning in Xenopus.

Animals↗

PubMed2000

Search for the decay K(L) --> pi(0)&mgr;(+)&mgr;(-)

We report on a search for the decay K(L)-->pi(0)&mgr;(+)&mgr;(-) carried out as a part of the KTeV experiment at Fermilab. This decay is expected to have a significant CP violating contribution and a direct measurement will either support the Cabibbo-Kobayashi-Maskawa mechanism for CP violation or point to new physics. Two events were observed in the 1997 data with an expected background of 0.87+/-0.15 events, and we set an upper limit B(K(L)-->pi(0)&mgr;(+)&mgr;(-))<3. 8x10(-10) at the 90% confidence level.

Journal Article↗

PubMed2000

Search for the weak decay of a lightly bound H0 dibaryon

We present results of a search for a new form of hadronic matter, a six-quark, dibaryon state called the H0, a state predicted to exist in several theoretical models. Analyzing data collected by experiment E799-II at Fermilab, we searched for the decay H0-->Lambdappi(-) and found no candidate events. We place an upper limit on [B(H0-->Lambdappi(-))dsigma(H)/dOmega]/(dsigma(Xi)/dOmega) and, in the context of published models, exclude the region of lightly bound mass states just below the LambdaLambda mass threshold, 2.194<M(H)<2.231 GeV/c(2), with lifetimes from approximately 5x10(-10) sec to approximately 1x10(-3) sec.

Journal Article↗

PubMed2000

Mental health. Facing hard truths.

A survey of 104 mental health units found that half did not have policies on treatment of detained patients from black and ethnic minority groups. Almost three-quarters had no policy for dealing with racial harassment of black and ethnic-minority patients. 11 percent of patients whose notes were examined had reported racial harassment.

Black or African American↗

PubMed2000

Observation of CP violation in K(L)-->pi(+)pi(-)e(+)e(-) decays

We report the first observation of a manifestly CP violating effect in the K(L)-->pi(+)pi(-)e(+)e(-) decay mode. A large asymmetry was observed in the distribution of these decays in the CP-odd and T-odd angle straight phi between the decay planes of the e(+)e(-) and pi(+)pi(-) pairs in the K(L) center of mass system. After acceptance corrections, the overall asymmetry is found to be [13.6+/-2. 5(stat)+/-1.2(syst)]%. This is the largest CP-violating effect yet observed when integrating over the entire phase space of a mode and the first such effect observed in an angular variable.

Journal Article↗

PubMed2000

Incisional hernia in a 5 mm laparoscopic port site incision.

Herniation of omentum or bowel through laparoscopic incision sites is uncommon. Herniations through 5 mm ports sites are very rare, with less than a handful described in the literature. Undoubtedly however, with the increasing interest.

Female↗

PubMed2000

The effect of the removal of the area postrema on insulin and IGF-1-induced cardiovascular and sympathetic nervous responses.

Previous studies have demonstrated that insulin and IGF-1 both increase lumbar sympathetic nerve activity (LSNA) and decrease mean arterial pressure (MAP). We hypothesized that the peripheral responses to insulin and IGF-1 are mediated, at least in part, via the central nervous system. In this study we determined the effects of the peripheral administration of both insulin and IGF-1 on cardiovascular dynamics and LSNA following removal of the area postrema (APX), a major site of blood-brain communication. Insulin infusion in normal rats decreased MAP but increased HR and LSNA. When insulin was infused in APX rats it also decreased the MAP but the MAP recovered rapidly and plateaued at a level equivalent to normals after 40 min. Insulin significantly increased the HR and LSNA in the APX rats compared to normals. However, when hypoglycemia was prevented by glucose infusion, the HR and LSNA responses to insulin in the APX rats were similar to normals. IGF-1 also decreased MAP and to a greater extent in the APX rats compared to normals but the increased LSNA in APX rats was equivalent to normals. The APX rats when compared to normals had a greater sensitivity to insulin-induced hypoglycemia while IGF-1 decreased the plasma glucose to a lesser degree in APX rats. We conclude that insulin and IGF-1 entry into the CNS at least via the area postrema does not contribute significantly to the hypotensive response and that the greater depressor response to IGF-1 is likely due to enhanced vascular sensitivity in APX rats. The increased HR and LSNA following insulin were likely mediated by an increased reflexive response to hypoglycemia.

Animals↗

PubMed1999

Mental health. As you don't like it.

The publication of the national service framework for mental health provides a good opportunity to review acute psychiatric services, which are unpopular with patients and understaffed. The framework recommends a balance of hospital beds, community provision and home care. Planning should usually cover one or more primary care groups.

Acute Disease↗