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Biomedical subjects

R Howell

Publications and source records attributed to R Howell.

At least 19 recordsLinked to original sources
PubMed2005

The further development and validation of the Liverpool Oral Rehabilitation Questionnaire: a cross-sectional survey of patients attending for oral rehabilitation and general dental practice.

BACKGROUND: Since the first version of the Liverpool Oral Rehabilitation Questionnaire (LORQ) was first published in 2004, the questionnaire has been modified to include more detail on chewing and appearance, and also details of denture, dental and implant status. AIM: The aim of this study is to report the ongoing development and validation of the LORQ version3. METHODS: A postal survey of the LORQv3 and OHIP-14 questionnaires was performed in April 2004 of 164 patients who had attended the oral rehabilitation clinic from February 2000. In addition The LORQv3 was administered to 349 patients attending six General Dental Practices, based in Liverpool, attending for routine care. RESULTS: Patients attending GDP scored appreciably better on most items in the LORQv3. The questionnaire discriminated between cancer and non-cancer oral rehabilitation patients in items such as swallowing, chewing, trismus, drooling and food clearance. There was no significant difference between rehabilitation groups for any of the seven OHIP-14 domains. The LORQv3 demonstrated good criterion validity when compared to the OHIP-14 with social items in the LORQv3 correlating well with items of the OHIP-14. Conversely various LORQv3 items did not have strong correlates within the OHIP-14 thus endorsing the additional items in the LORQv3.

Adolescent↗
PubMed2005

Trends in head and neck microvascular reconstructive surgery in Liverpool (1992-2001).

Microvascular reconstructive techniques in head and neck surgery are well established, but we are now entering an era of modification exemplified by perforator and free style free flaps. We present a review of the database introduced into the unit in 1992 over a 10-year period, during which time 977 patients with malignant disease were operated on and 620 defects were reconstructed with free flaps. There were 358 radial forearm flaps, 78 composite radial forearm flaps, 84 iliac crest flaps, 43 fibular flaps, 24 from the scapula, 26 from the latissimus dorsi, 4 from the rectus abdominis, and 3 from the lateral arm. The main changes over this time have been the use of more bulky flaps for larger resections of the tongue and the preference for iliac crest flaps over those from the fibula and forearm for composite reconstructions. Improving reliability of tissue transfer remains an important aim, and further development of reliable objective methods of monitoring of flaps is required.

Anastomosis, Surgical↗
PubMed2005

Survey of oral rehabilitation in a consecutive series of 130 patients treated by primary resection for oral and oropharyngeal squamous cell carcinoma.

The purpose of this study was to investigate the use of oral rehabilitation in a group of patients who had primary resection of oral and oropharyngeal squamous cell carcinoma. Of 132 consecutive patients operated on for previously untreated disease between January 1995 and June 1997, 130 were recruited. The University of Washington Quality of Life questionnaire was completed on the day before operation at 6 and 12 months, and at last review. A larger similar dataset was used to predict survival. Twenty-eight patients (22%) were seen by the oral rehabilitation team. The median (IQR) time from operation to start of treatment was 12 months (6-21). The median (IQR) time from beginning to end of rehabilitation was 14 months (5-49). Patients with larger tumours (P=0.06) and patients who were edentulous with dentures in the maxilla (P=0.07) were most likely to be seen for oral rehabilitation.

Aged↗
PubMed2005

Inherited pericentric inversion (X)(p11.4q11.2) associated with delayed puberty and obesity in two brothers.

We report two brothers with hypogonadotropic hypogonadism (HH), obesity and short stature associated with a maternally inherited pericentric inversion (X)(p11.4q11.2). On the basis that either breakpoint might disrupt a gene whose function is critical to normal sexual development we mapped the chromosomal breakpoints using two-colour fluorescent in situ hybridisation (FISH). The position of both the Xp11.4 and Xq11.2 breakpoints was refined using a panel of ordered BAC clones. No known genes were shown to map to the breakpoint regions. While we cannot entirely exclude the possibility that association between the clinical and cytogenetic phenotypes in the family is coincidental, it is possible that the inversion is responsible for HH through alternative molecular mechanisms such as position effects.

Adolescent↗
PubMed2004

The Liverpool Oral Rehabilitation Questionnaire: a pilot study.

There are several validated health-related quality of life (HRQOL) questionnaires designed to record patient-derived outcomes in head and neck cancer. None deals specifically with oral rehabilitation. The aim of this study was to pilot a new questionnaire, the Liverpool Oral Rehabilitation Questionnaire (LORQ). The questionnaire consists of 25 items about oral function and denture satisfaction. A four-point Likert scale is used. Sixty-one consecutive patients attending oral rehabilitation clinics completed the LORQ in combination with the University of Washington Head and Neck questionnaire version 3 (UW-QOL) and European Organisation for Research and Treatment of Cancer H and N quality of life questionnaire (EORTC H and N 35). Forty-two patients received questionnaires at baseline, whereas the rest were provided with the questionnaires at various stages of oral rehabilitation. For each item on the questionnaire, a full range of possible responses were given by patients. Kappa coefficients of agreement for test-retest data indicated moderate to very good agreement between repeat questionnaires. There were significant correlations (P < 0.001) between items in the LORQ and those in the UW-QOL and EORTC HN questionnaires. The LORQ also identified differences in responses between non-cancer and cancer groups of patients undergoing oral rehabilitation. This study of the LORQ is encouraging, although data on its responsiveness over time and to intervention is awaited.

Atrophy↗
PubMed2000

Characterization of fusion burn time in exploding deuterium cluster plasmas

Exploiting the energetic interaction of intense femtosecond laser pulses with deuterium clusters, it is possible to create conditions in which nuclear fusion results from explosions of these clusters. We have conducted high-resolution neutron time-of-flight spectroscopy on these plasmas and show that they yield fast bursts of nearly monochromatic fusion neutrons with temporal duration as short as a few hundred picoseconds. Such a short, nearly pointlike source now opens up the unique possibility of using these bright neutron pulses, either as a pump or a probe, to conduct ultrafast studies with neutrons.

Journal Article↗
PubMed1999

Relationship of arithmetic problem solving and reflective-impulsive cognitive styles in third-grade students.

Different individuals approach mathematical problems in a variety of ways, with these different approaches also reflected in over-all cognitive styles. This investigation had two purposes, first, to determine whether good and poor arithmetic problem solvers differ substantially in cognitive style, and second, to determine whether the students, after training in techniques of solving arithmetic problems, improve their performance with no significant change in cognitive style. A total of 98 third graders participated (mean age 8.1 yr.; 50 boys, 48 girls). The Matching Familiar Figure Test was used to classify the students by cognitive style as either Reflective or Impulsive. Students also were given training with different problem-solving exercises for different arithmetic problems. The training program in problem-solving strategies did not improve performance on arithmetic problems for Reflective students; however, Impulsive students' performance did improve after training.

Child↗
PubMed1998

99mTc-labelled SM3 in the preoperative evaluation of axillary lymph nodes and primary breast cancer with change detection statistical processing as an aid to tumour detection.

The extent of primary surgery for breast cancer could be tailored to the patient if previous information on the presence or absence of lymph node involvement could be reliably determined. Prospective radioimmunoscintigraphy in 29 patients with primary breast cancer that was found on screening has been undertaken with 555 MBq (15 mCi) 99mTc SM3, an Imperial Cancer Research Fund (ICRF) murine monoclonal antibody, 0.5 mg with images at 10 min and 22 h, and analysis using a change detection algorithm. Sites of significant change between the early and later images were displayed as a map of probabilities. Image-positive and -negative axillary lymph nodes were compared by histology in the 28 evaluable patients. The correct identification of the presence or absence of node involvement, even if impalpable, has been shown in 24 out of 28 patients (29 lymph node groups). Sensitivity was 90% (nine out of ten), specificity 84% (16 out of 19) and accuracy 86%. These results encourage further assessment of this technique.

Adult↗
PubMed1998

Role of tensor fasciae latae in abdominal wall reconstruction.

The role of the tensor fasciae latae as autogenous tissue in reconstruction of abdominal wall defects is well established. The use of various forms of the tensor fasciae latae (free graft versus pedicled flap versus free flap) is determined by the characteristics of the defect. A review of abdominal wall reconstructions using tensor fasciae latae was completed to determine efficacy and establish guidelines for its use. Abdominal wall reconstructions from 1991 to 1994 using tensor fasciae latae were reviewed. Demographics, wound characteristics, and complications were evaluated. Twenty-seven patients with a mean follow-up of 23.6 months underwent abdominal wall reconstruction with the tensor fasciae latae: free grafts, 12; pedicled flaps, 9; and free flaps, 6. An average defect size of 14.4 x 13.1 cm was seen. Fourteen (52 percent) of the reconstructions were completed in contaminated or infected wounds. One recurrent enteric fistula was seen. Twelve (44 percent) of the patients had flap complications of which 50 percent involved partial flap necrosis. Donor site complications were seen in five patients (18 percent) and included a hematoma, seroma, and two cases of skin graft dehiscence along the edge of the wound. Tensor fasciae latae free grafts are an option for repair of abdominal hernias if abdominal soft tissue is adequate. Pedicled flaps may be used for defects of soft tissue and fascia but are limited by the arc of rotation and size of the defect. Tensor fasciae latae free flaps are versatile in orientation and may be used for supraumbilical defects. Tip necrosis is significant in both types of vascularized flaps.

Abdominal Muscles↗
PubMed1997

Elevated serum lipoprotein(a) levels in young women with endometriosis.

Elevated serum lipoprotein(a) [Lp(a)] levels increase the risk of cardiovascular disease if levels of low-density lipoproteins (LDLs) are also high. The biological function of Lp(a) is unknown, but plasma levels may be elevated in inflammatory disease. Endometriosis is a common gynecologic disorder in which endometrial tissue is found outside of the lining of the uterine cavity. There is an immune component to this condition whereby the number of peritoneal macrophages is increased and the level of prostanoids and cytokines in peritoneal fluid is elevated. In the present study, we measured serum lipid, lipoprotein, and apolipoprotein levels in 29 women with endometriosis and in 29 matched healthy controls. Fasting serum triglyceride and apolipoprotein (apo) Al levels were higher in women with endometriosis (+28.1%, P < .001, and +12.3%, P < .01, respectively), but there were no significant differences in LDL or high-density lipoprotein (HDL) cholesterol levels. Serum Lp(a) levels were fivefold higher (P < .01) in the patients (median, 15.0 mg/dL; range, 0.05 to 60.0) than in controls (median, 3.1 mg/dL; range, 0.05 to 57.2). The distribution of apo(a) isoforms was similar in the two groups, but in women with endometriosis the individual apo(a) isoforms tended to be associated with higher serum Lp(a) levels. Endometriosis may represent a relatively common condition in which to investigate the role of Lp(a) in human metabolism.

Adult↗
PubMed1997

The ability to form intrastrand tetraplexes is an evolutionarily conserved feature of the 3' end of L1 retrotransposons.

Mammalian genomes contain many thousands of members of a family of retrotransponsons known as L1 (or LINE-1) elements. These elements lack long terminal repeats (LTRs), and are thought to use a retroposition mechanism than differs from that of retroviruses and other LTR-containing retroelements. In order to define those regions of the L1 element that may be important for L1 retroposition, we examined the 3' untranslated regions (UTRs) of L1 elements from a diverse group of mammals. We show that while the 3' UTRs of L1 elements from different species share little if any sequence homology, they all contain a G-rich polypurine tract of variable length and sequence which can form one or more intrastrand tetraplexes. This conservation over the 100 Myr since the mammalian radiation suggests that either the G-rich motif itself or a conserved structure such as the tetraplex that can be formed by this motif is a significant structural feature of L1 elements and may play a role in their propagation.

Animals↗
PubMed1997

Management of the infected median sternotomy wound with muscle flaps. The Emory 20-year experience.

OBJECTIVE: The purpose of the study is to define those patient variables that contribute to morbidity and mortality of median sternotomy wound infection and the results of treatment by debridement and closure by muscle flaps. BACKGROUND: Infection of the median sternotomy wound after open heart surgery is a devastating complication associated with significant mortality. Twenty years ago, these wounds were treated with either open packing or antibiotic irrigation, with a mortality approaching 50% in some series. In 1975, the authors began treating these wounds with radical sternal debridement followed by closure using muscle or omental flaps. The mortality of sternal wound infection has dropped to < 10%. METHODS: The authors' total experience with 409 patients treated over 20 years is described in relation to flap choices, hospital days after sternal wound closure, and incidence rates of morbidity and mortality. One hundred eighty-six patients treated since January 1988 were studied to determine which patient variables had impact on rates of flap closure complications, recurrent sternal wound infection, or death. Variables included obesity, history of smoking, hypertension, diabetes, poststernotomy septicemia, internal mammary artery harvest, use of intra-aortic balloon pump, and perioperative myocardial infarction and were analyzed using chi square tests. Fisher's exact tests, and multivariable logistic regression analysis. RESULTS: The mortality rate over 20 years was 8.1% (33/49). Additional procedures for recurrent sternal wound infection were necessary in 5.1% of patients. Thirty-one patients (7.6%) required treatment for hematoma, and 11 patients (2.7%) required hernia repair. Among patients treated since 1988, variables strongly associated with mortality were septicemia (p < 0.00001), perioperative myocardial infarction (p = 0.006), and intra-aortic balloon pump (p = 0.0168). Factors associated with wound closure complications were intra-aortic balloon pump (p = 0.0287), hypertension (p = 0.0335), and history of smoking (p = 0.0741). Factors associated with recurrent infection were history of sternotomy (p = 0.008) and patients treated for sternal wound infection from 1988 to 1992 (p = 0.024). Mean hospital stay after sternal wound reconstruction declined from 18.6 days (1988-1992) to 12.4 days (1993-1996) (p = 0.005). To clarify management decisions of these difficult cases, a classification of sternal wound infection is presented. CONCLUSIONS: Using the principles of sternal wound debridement and early flap coverage, the authors have achieved a significant reduction in mortality after sternal wound infection and have reduced the mean hospital stay after sternal wound closure of these critically ill patients. Further reductions in mortality will depend on earlier detection of mediastinitis, before onset of septicemia, and ongoing improvements in the critical care of patients with multisystem organ failure.

Debridement↗
PubMed1996

Azole phenoxy hydroxyureas as selective and orally active inhibitors of 5-lipoxygenase.

Azole phenoxy hydroxyureas are a new class of 5-lipoxygenase (5-LO) inhibitors. Structure-activity relationship studies have demonstrated that electronegative substituents on the 2-phenyl portion of the oxazole tail increased the ex vivo potency of these inhibitors. Similar substitutions on the thiazole analogs had only minor contribution to the ex vivo activity. The trifluoromethyl-substituted oxazole 24 was the best compound of the oxazole series in both the ex vivo (6 h pretreated rats) and in vivo (3 h pretreated rats) RPAR assay with ED50 values of approximately 1 and 3.6 mg/kg, respectively, but was weakly active in the allergic guinea pig assay. Oxazole 50 was equally active in both the RPAR and guinea pig in vivo models and was similar to zileuton. The unsubstituted thiazole 52 was the best compound of the thiazole series, by inhibiting the leukotriene B4 biosynthesis in the RPAR assay (3 h pretreated rats) by 99%, at an oral dose of 10 mg/kg, and the bronchoconstriction in the allergic guinea pig by 50%, at an intravenous dose of 10 mg/kg. Oxazole 24 demonstrated high and selective 5-LO inhibitory activity in the in vitro assays, with IC50 values ranging from 0.08 microM in mouse macrophages to 0.8 microM in human peripheral monocytes to 1.2 microM in human whole blood. This activity was selective for 5-LO, as concentrations up to 15 microM in mouse macrophages did not affect prostaglandin formation. Oxazole 59 was the most active inhibitor in the human monocyte assay with an IC50 value of 7 nM.

Animals↗
PubMed1996

Breast cancer 99mTc SM3 radioimmunoscintigraphy.

99mTc SM3 radioimmunoscintigraphy is combined with kinetic analysis and probability mapping using a change detection algorithm to investigate axillary node involvement before primary surgery in patients with breast cancer. Whereas planar imaging was unsuccessful, axillary node involvement was correctly determined in 11 out of 13 patients 6 out of 7 true negatives and 5 out of 6 true positives down to 0.35 grams. A prospective study is underway.

Adult↗
PubMed1995

Gonadotropin-releasing hormone analogue (goserelin) plus hormone replacement therapy for the treatment of endometriosis: a randomized controlled trial.

OBJECTIVE: To determine whether treatment of endometriosis with a GnRH analogue (GnRH-a; goserelin) combined with continuous estrogen and progestogen hormone replacement therapy (HRT) would prevent the hypoestrogenic effects, including loss of bone density, while maintaining efficacy for treatment of endometriosis. DESIGN: Randomized controlled trial. PATIENTS: Fifty premenopausal women with laparoscopically diagnosed endometriosis (revised American Fertility Score for endometriosis implants equal to four or greater) and significant symptoms of dysmenorrhoea, dyspareunia, and other pelvic pain. INTERVENTION: Patients were randomized to receive either goserelin alone, 3.6 mg SC depot every 4 weeks for 24 weeks, or goserelin, 3.6 mg SC depot every 4 weeks for 24 weeks, plus HRT (25 micrograms transdermal 17 beta E2 daily and 5 mg medroxyprogesterone acetate orally daily) for 20 weeks commencing with the second goserelin injection. RESULTS: There was a significant reduction in the extent of pelvic endometriosis in both groups, with no difference between the groups. Both groups experienced an improvement in symptoms and signs, again with no difference between groups. Hypoestrogenic side effects of hot flushes and loss of libido were significantly less in the group that received HRT. The amount of bone mineral density loss was significantly less in the HRT group at the lumbar spine, although it was not prevented completely. CONCLUSION: The addition of HRT to GnRH-a for the treatment of endometriosis did not reduce the efficacy of treatment, and adverse hypoestrogenic effects were decreased, although not abolished.

Adult↗
PubMed1995

Effects of the pure anti-oestrogen ICI 182780 on oestrogen receptors, progesterone receptors and Ki67 antigen in human endometrium in vivo.

The new steroidal pure anti-oestrogen ICI 182780 was studied for the first time in pre-menopausal women. A total of 30 patients requiring hysterectomy for benign gynaecological disease were randomized to ICI 182780, 12 mg/day i.m. (n = 19) or no treatment (n = 11) for 7 days prior to surgery. Immunohistochemical measurements were made in the snap-frozen, resected endometrium for oestrogen receptors (ER), progesterone receptors (PgR) and Ki67, a nuclear antigen whose expression is closely related to proliferation. Five control patients ovulated prior to surgery and, as expected, the secretory endometria had lower Ki67 antigen concentrations than endometria had lower proliferative phase. The endometria from patients treated with ICI 182780 had reduced Ki67 compared with controls. This demonstration of reduced proliferative activity indicates that the pharmacological effectiveness of the treatment was maintained despite increased plasma oestradiol concentrations. In contrast to results from rodents, ICI 182780 did not markedly reduce ER expression, although there was significantly lower ER in the myometrial cells of the treated group. The lack of effect on PgR shows a dissociation between the drug's effect on this oestrogen-dependent protein and its effects on proliferation.

Adult↗