Search PubMed⌕ Search

Biomedical subjects

R Sanders

Publications and source records attributed to R Sanders.

At least 55 records · Page 3Linked to original sources
PubMed2000

Percutaneous fixation of proximal humeral fractures.

The purpose of the current study is to evaluate the technique of closed reduction and percutaneous pinning of proximal humeral fractures and to determine whether this technique provides enough stability to permit early active range of motion and subsequent fracture healing. Fractures were classified according to Neer et al and were included if the surgical or anatomic neck were angulated greater than 45 degrees, separation between fragments was greater than 1 cm, or the greater tuberosity was displaced more than 0.5 cm. There were 21 Type II, 16 Type III, and four Type IV fractures. Fractures were pinned using distally threaded Dynamic Hip Screw guide pins, 2-mm Kirschner wires, or 2.5-mm distally threaded Schantz pins. Patients were evaluated for union rates and motion. Assessment was made using the Modified American Shoulder and Elbow Surgeons Form. Thirty-six patients with 37 fractures were available for review with followup averaging 40 months (range, 12-68 months). All patients with Neer Type IV fractures did not respond to fixation and three had avascular necrosis develop, irrespective of the type of pin used. In the remaining 33 patients with Neer Type II and Type III fractures, a union rate of 94% was observed at an average of 2.6 months. All patients had good functional results. In the current series, there were no failures using Schantz pins. There was a 20% failure rate with Dynamic Hip Screw pins (2% if the patients with Type IV fractures were excluded) and a 100% failure rate with Kirschner wires. Stable fixation with early motion and subsequently good results can be obtained using percutaneous fixation in patients with Type II and Type III fractures; however, terminally threaded pins must be used and smooth Kirschner wires must be avoided. Percutaneous fixation cannot be recommended in patients with Type IV fractures.

Adult↗
PubMed2000

Treatment of femoral shaft fracture using unreamed interlocked nails.

OBJECTIVE: To evaluate healing rates of femoral shaft fractures treated with interlocked nails inserted without reaming. STUDY DESIGN: Review of prospectively collected data. SETTING: Level I trauma center. METHODS: From the trauma registry, 159 patients with 164 femoral shaft fractures were identified who had been treated from March 1993 through December 1995 with femoral nails inserted without reaming in either an antergrade or retrograde manner. Fractures were classified according to the AO/OTA method. Patients were followed for a minimum of one year with clinical and radiographic examinations. RESULTS: One hundred twenty-one patients with 125 fractures were available for review. Average follow-up was 18.3 months (range 12 to 59 months). One hundred sixteen of the 125 fractures (93 percent) healed after the index procedure. Type A fractures healed at an average of 3.8 months (range 2 to 8 months), Type B fractures at 4.8 months (range 2 to 16 months), and Type C fractures at 6.2 months (range 3 to 12 months). There were no increases in complication rates or differences in ranges of knee and hip motion as compared with other published series. Overall, there was no difference in the length of time to union between antegrade or retrograde nailings, and the healing rates for the two methods showed only a small statistical difference. CONCLUSIONS: The use of femoral nails inserted in an unreamed manner in this series produced healing rates comparable with historic standards using reamed insertion. Smaller diameter nails inserted without reaming did not compromise fracture management and produced no increase in complication rates. The causes for delayed union or nonunion appear to be multifactorial, and secondary procedures should be considered if fractures have demonstrated little or no healing by three months.

Adolescent↗
PubMed2000

Magnesium levels in critically ill patients. What should we measure?

We studied the relation between ionized magnesium, total magnesium, and albumin levels in serum of 115 critically ill patients and the role of extracellular and intracellular magnesium in outcome prediction. Levels of serum total and ionized magnesium, serum albumin, and magnesium in mononuclear blood cells and erythrocytes were measured and the APACHE II score and 1-month mortality recorded. Of all patients, 51.3% had a serum total magnesium concentration below the reference range. In 71% of these hypomagnesemic patients, a normal serum ionized magnesium concentration was measured. None of the patients had an intracellular magnesium concentration below the reference limit. Except for serum total and ionized magnesium, none of the magnesium parameters correlated significantly with each other. A significantly negative correlation was found between serum albumin and the fraction ionized magnesium. There was no association between low extracellular or intracellular magnesium and clinical outcome. The observation of hypomagnesemia in critically ill patients depends on which magnesium fraction is measured. The lack of correlation with clinical outcome suggests hypomagnesemia to be merely an epiphenomenon. Reliable concentrations of serum ionized magnesium can be obtained only by direct measurement and not by calculation from serum total magnesium and albumin.

Cations, Divalent↗
PubMed2000

Three-dimensional analysis of the child cleft face.

OBJECTIVE: This study examined the facial surfaces of cleft children and unaffected children aged 8-11 years with the aim of identifying and assessing differences in their facial surface morphology. The investigation was carried out using an Optical Surface Scanner, an instrument that utilizes laser light to construct and archive a three-dimensional image of the face suitable for linear measurement and direct surface comparisons. DESIGN, SETTING, AND PATIENTS: Thirty-nine cleft lip and palate (CLP) patients and 25 unaffected subjects were voluntarily recruited from two southeast England hospitals. A range of linear facial measurements was compared. Three-dimensional differences between the cleft subgroups and the control group were visualized by superimposition of averaged cleft scans over the averaged control group images. RESULTS: Statistically significant dimensional differences (p < or = .05) in interocular width, nose base widths, mouth widths, and nose base/mouth width ratios were found between the cleft group and the control group. Qualitative differences over the whole of the face were readily demonstrated between the groups by superimposition. Face width and submandibular area depth differed consistently between the groups, the cleft face appearing narrower with a deeper submandibular area. CONCLUSION: Significant differences exist between the facial surface morphology of CLP patients and control subjects.

Analysis of Variance↗
PubMed2000

An investigation of the dentition of parents of children with cleft lip and palate.

OBJECTIVE: The aim of this investigation was to identify whether any dental features in parents of children with cleft lip and palate can be useful as predictors of clefting. METHODS: The dentition of 28 pairs of parents of children with complete unilateral (17) and bilateral (11) cleft lip and palate and 21 pairs of parents of noncleft children were evaluated. Clinical and radiographic examinations were carried out to identify abnormalities of tooth number and morphology. Study cast assessment was undertaken to evaluate incisor relationship, overjet, overbite, intercanine widths, and mesiodistal widths of individual teeth, and these data were subjected to statistical analysis. RESULTS: The prevalence of abnormalities of tooth number in parents of cleft children was similar to those reported elsewhere for general populations. In parents of children with unilateral clefts, there was no tooth-size asymmetry between teeth on the side corresponding to the child's cleft and noncleft sides, respectively. No differences were found in tooth widths and intercanine widths between parents of children with unilateral clefts and parents of children with bilateral clefts. The incisor relationship, overjet, overbite, and intercanine widths were found not to differ statistically between the parents of cleft children and parents of noncleft children. CONCLUSIONS: No predictors of clefting could be identified in the dentition of parents of children with cleft lip and palate.

Adult↗
PubMed2000

The influence of learning styles on collaborative performances of allied health students in a clinical exercise.

With the increasing emphasis on interdisciplinary practice, there is a need to recognize factors that promote effective interdisciplinary teams. The influence of individual learning-style preference on collaborative performance was examined in 78 occupational and physical therapy students in a neuroscience course. They were randomly assigned in pairs to one of three subsets based upon their Kolb Learning Style Inventory scores (active experimenters vs reflective observers). The students viewed a videotape of a quadriplegic patient's physical examination and completed a collaborative exercise that required performance skills on all levels of Bloom's taxonomy of learning. Analysis of variance revealed no significant difference among learning-style subset pairs in performance (F2, 36 = 0.43, p > 0.05), but the exercise's overall grade correlated with the average of the pair's highest individual scores on two prior written exams (r = 0.631, p < 0.05), suggesting that background knowledge may predict performance better than learning styles do. It is suggested that differences in information-processing styles as measured by the Kolb inventory do not affect interdisciplinary team performance.

Adult↗
PubMed1999

Fibre type specificity of haem oxygenase-1 induction in rat skeletal muscle.

The expression of the inducible haem oxygenase (HO-1) gene was examined in different skeletal muscles. Rats were treated with haemin and a time course of HO-1 mRNA expression was determined in soleus and extensor digitorum longus (EDL) muscles. Fibre type composition and tissue myoglobin content were also measured. We found that HO-1 mRNA expression markedly increased in soleus (type I fibres) muscle but was only slightly affected in EDL (type II fibres). HO-1 expression directly correlated with both percentage of red fibres and tissue myoglobin. These data demonstrate that HO-1 gene expression follows a fibre type-specific pattern which might indicate an important role for this protein in the maintenance of skeletal muscle function.

Adenosine Triphosphatases↗
PubMed1999

Child abuse fatalities and cases of extreme concern: lessons from reviews.

OBJECTIVE: The study was commissioned by the Welsh Office to pull together lessons from all reports on cases involving either a child abuse fatality or serious child protection concern ("Part 8 Reviews") since the introduction of the Children Act 1989. METHOD: Twenty-one such reports were identified and subjected to a content analysis to extract practice issues. RESULTS: From 19 reports (excluding Reviews concerning adult sexual abusers), the authors identify seven practice themes emerging from that analysis which are related to those identified in previous studies and to six previously undertaken British overviews of child abuse fatalities. The themes are assessment, interagency communications, responsibility, number of professionals involved, role of general practitioners, insufficient training for pediatricians/radiologists, and parental choice. CONCLUSIONS: British child protection agencies are attempting to address apparently conflicting policy objectives. On the one hand they are required to ensure the protection of the most vulnerable children within the child protection system. At the same time they are also being encouraged to adopt a "lighter touch" in child protection work. The authors conclude that the seven themes may provide some indicators as to how these conflicting objectives may be reconciled.

Adult↗
PubMed1999

Mining the Swedish clinical archives to develop pharmacogenomic tests.

Eurona Medical is a Swedish company that develops diagnostic tests to predict response to drugs or treatment. Sweden offers unparalleled retrospective clinical data resources, with epidemiological registers and collections of tissue samples built up over decades. Efficient pharmacogenomic research can be performed using these registers and sample collections in collaboration with experienced medical researchers. Eurona's tests are based on Genetic Signatures, groups of polymorphic, polygenic genomic positions linked to and therefore predictive of drug response. These are elucidated from complex data sets using unique applications of multivariate and combinatorial statistics and a multigenic approach. The company develops tests applicable to current medical practice and is preparing to launch its first within the hypertension field. Quality control (including ISO9001 certification) and clinical regulatory compliance are applied throughout all programs to produce data that can be directly translated into clinical tests.

Archives↗
PubMed1999

The physical demands of Olympic yacht racing.

The primary purpose of this study was to quantify the up wards forces of the feet on the hiking strap and the forces in the mainsheet of four Olympic classes of racing dinghies (Europe, Laser. Finn and 470) during realistic on-water sailing in varying wind conditions. The secondary aim of the study was to measure the joint angles adopted by the sailors and boat heel angles. The tertiary aim was to identify events and sailing conditions associated with large or patterned force production. Forces in the hiking strap and mainsheet of four classes of Olympic sailing dinghies were measured on eleven New Zealand sailors during simulated on-water racing in a range of wind conditions. Up-wind hiking strap forces reached an average of 73-87% of predicted maximal voluntary contraction (pred MVC), with peak forces exceeding 100% pred MVC. Mainsheet forces reached 25-35% pred MVC, with peak forces reaching 40-50% pred MVC. Off-wind hiking strap and mainsheet forces were considerably lower than up-wind forces. Ankle and hip joint angles increased and knee joint angles decreased with increasing wind speed during up-wind sailing. Large forces occurred in the hiking strap and mainsheet when boats reached the tops of wave during up-wind sailing in high wind speeds and when a gust of wind hit the boat. During off-wind sailing large forces were observed in the mainsheet when surfing down waves. It is recommended that the intensities and joint angles found in this study be used as a basis for the development of class specific off-water physical conditioning programmes.

Biomechanical Phenomena↗
PubMed1999

Hair removal using the ruby laser: clinical efficacy in Fitzpatrick skin types I-V and histological changes in epidermal melanocytes.

The ruby laser is effective in removing unwanted body hair. The occurrence of cutaneous side-effects such as blistering, hypopigmentation and hyperpigmentation, however, remains problematic. These side-effects are more commonly seen in patients with dark coloured skin, which partly explains the relative scarcity of information on the efficacy of ruby laser hair removal in such patients. The mechanisms of the occurrence of these side-effects are also not known. It was the aim of this study to evaluate the efficacy of ruby laser-assisted hair removal in patients with Fitzpatrick skin type V in a retrospective clinical study and to evaluate the mechanism of post-treatment pigmentary change in a prospective clinical study. The percentage reduction in hair density in patients with skin type V was assessed after a variable period following treatment with the Chromos 694 Depilation Ruby Laser, and was compared with the results of those with skin types I-IV. To study the pigmentary change and melanocyte numbers after laser irradiation, ex-vivo scalp skin and serial patient biopsies were taken and stained with S-100, dopa oxidase and Masson-Fontana methods. Laser treatment reduced melanocyte numbers as measured by DOPA stain but not by S100. Laser treatment resulted in the clearance of pigment from the epidermis on histology. Ruby laser was shown to be effective in removing unwanted hair from patients with dark coloured skin, but with a higher incidence of cutaneous side-effects. The occurrence of hypopigmentation after laser irradiation was thought to be due to the suppression of melanogenesis in the epidermis rather than to destruction of the melanocytes.

Analysis of Variance↗
PubMed1999

Ruby laser-assisted hair removal reduces the coarseness of regrowing hairs: fallacy or fact?

There have been anecdotal reports that hairs that regrow after ruby laser-assisted hair removal are finer in appearance. If true, this phenomenon adds to the improved aesthetic effect of laser treatment of unwanted hair. It is the aim of this study to determine whether this phenomenon indeed occurs, and if so, assess its permanence and its mode of action. In this prospective clinical study, 71 patients with 94 treatment sites were treated with the Chromos 694 Depilation Ruby Laser. Hair diameter was measured pre-treatment, and at 3 and 7 months post-treatment. In addition, ex vivo scalp skin was used to assess if the ruby laser selectively damaged coarser hairs. Laser-treated and matched untreated skin samples were histologically assessed and the diameters of hair shafts (normal or obviously damaged) were measured. Results of this study were analysed using Kruskal-Wallis one-way analysis. There was no statistically significant difference between the hair diameter of non-lasered specimens and the hair diameter of the normal hair in lasered specimens. However, a statistically significant difference was seen between the hair diameter of non-lasered specimens and diameters of damaged hair in lasered specimens (P < 0.05). There was a statistically significant difference (P < 0.05) between pre-treatment and 3 month hair diameters, but no statistically significant difference was found between pre-treatment and 7 month hair diameters. In conclusion, ruby laser-assisted hair removal results in a temporary reduction in hair diameter of regrowing hair. This is not due to the selective targeting of larger hair follicles.

Adolescent↗
PubMed1999

Measurement of c-myc oncogene expression provides an accurate prognostic marker for acral lentiginous melanoma.

Acral lentiginous melanoma is a particularly aggressive tumour with a worse prognosis than other varieties of primary cutaneous melanoma. In order to study the biology of this disease, the activity of the c-myc oncogene was studied in tumours from 45 patients using flow cytometry. High levels of oncoprotein were found in all tumours and exceeded that documented in other varieties of cutaneous melanoma. Survival analysis with stratification of patients according to oncogene activity provided a useful prognostic marker with shorter disease free interval (Log-Rank test, chi 2 = 16.7, P < 0.0001) and overall survival (Log-Rank test, chi 2 = 8.9, P = 0.002) in tumours with high oncoprotein levels. Multivariate analysis revealed c-myc oncogene expression to be more accurate in predicting clinical outcome than all existing clinicopathological parameters including the Breslow depth (Cox's proportional hazards model, P = 0.0011). This study provides biological evidence to explain the aggressive behaviour of acral melanoma and supports the application of oncogene measurement as an accurate prognostic marker.

Adult↗
PubMed1999

A functional variant of lower lip reconstruction.

A functional variant of lower lip reconstruction is reported, in which a nasolabial skin flap was combined with upward transposition of the inferior part of the orbicularis oris muscle in a 'bucket-handle' fashion. The tongue was split to provide both an intraoral lining to the lip and a new vermilion.

Animals↗
PubMed1999

Ruby laser-assisted hair removal: an ultrastructural evaluation of cutaneous damage.

Ruby laser-assisted hair removal is thought to act via selective photothermolysis of melanin in the hair follicles. Although initial clinical trials of permanent hair removal using ruby lasers are promising, the exact mechanisms of hair destruction and the potential damage to other structures of skin are not known. The aim of this study was to evaluate the cutaneous ultrastructural changes following ruby laser hair removal. Nineteen healthy Caucasian patients with dark (brown/black) hair were treated with the ruby laser and biopsies taken after 0, 2, 3, 5, 7, 14 and 21 days. Specimens were examined by light and electron microscopy. Laser-treated specimens showed widespread coagulation and charring of subcutaneous hair shafts. These obviously damaged follicles were randomly dispersed amongst intact follicles within the same treatment sites. Microscopic changes were also seen in the basal epidermis where melanin was concentrated, irrespective of any obvious macroscopic damage. A low level of inflammatory response seen up to 2 weeks after treatment always followed laser treatment. Suprabasal epidermal necrosis was only seen in patients with blister formation after treatment. Ruby laser irradiation results in selective damage to the hair follicles, with microscopic changes to the basal epidermis. The damage is probably compounded by the inflammatory response to the damaged hair. The normal appearance and distribution of collagen in the dermal layer supported the clinical evidence that laser-assisted hair removal, if performed correctly, does not lead to scar formation.

Biopsy↗
PubMed1999

Is Dupuytren's disease caused by an imbalance between proliferation and cell death?

Dupuytren's contracture shares certain properties with malignant tumours, characterized by proliferation and lack of apoptosis, which may be induced by the c-myc oncogene. Because of these similarities, the relationship between the c-myc oncogene expression, bcl-2 oncogene (anti-apoptotic gene) and proliferation was investigated in Dupuytren's disease. Proliferation was assessed by immunohistochemical staining of the mib-1 antibody. Results were compared with those from fibrosarcoma specimens, representing a related malignant tumour. Non-diseased fascia from Dupuytren patients and flexor retinaculum from patients undergoing carpal tunnel release without Dupuytren's disease were used as controls. Expression of c-myc was elevated in primary Dupuytren's disease and fibrosarcoma specimens, whilst recurrent Dupuytren's disease, non-diseased Dupuytren fascia and flexor retinaculum exhibited significantly lower levels. Neither bcl-2 nor mib-1 were detected in Dupuytren's disease, non-diseased fascia or flexor retinaculum, in contrast to fibrosarcoma. The imbalance between proliferation and apoptosis, producing malignant growth was thus confirmed for fibrosarcoma, but not for Dupuytren's disease.

Adult↗
PubMed1999

The effect of ruby laser light on ex vivo hair follicles: clinical implications.

Several clinical studies on the efficacy of ruby laser-assisted hair removal have reported that regrowth of hair after treatment is common. One of the reasons for the regrowth of hair is the incomplete destruction of germinative hair cells due to the insufficient penetration of the ruby laser in the skin. It was the aim of this study to estimate the extent of damage to the hair follicles after one ruby laser treatment and to determine whether the ruby laser destroyed the bulbs and the bulge regions of hair follicles. The extent of laser damage in hair shafts was determined by serial examination of six specimens of ex vivo scalp skin lasered with the Chromos 694 Depilation Ruby Laser at 14 J per square centimeter and 20 J per square centimeter. Another nine specimens of ex vivo scalp skin were similarly lasered, and monoclonal antibody LP2K was used to identify the bulge regions of the hair follicles using the immunoperoxidase technique. Damage to the bulge region was assessed from consecutive specimens, which were stained with hematoxylin-eosin stain. The mean depth of laser damage sustained by hair follicles was 1.34 mm (14 J per square centimeter) and 1.49 mm (20 J per square centimeter) underneath the skin surface. Most of the laser damage involved the bulge regions but fell short of the hair bulbs. The laser damage did not seem to extend far enough down the hair shafts to result in permanent hair destruction. The clinical implications of this finding are discussed.

Hair Follicle↗