Search PubMed⌕ Search

Biomedical subjects

R Sanders

Publications and source records attributed to R Sanders.

At least 109 records · Page 6Linked to original sources
PubMed1997

A theoretical framework for evaluating the sensitivity of surveillance for detecting wild poliovirus: II. Factors affecting detection sensitivity in a population with circulating wild poliovirus.

A basic framework for describing sensitivity of surveillance to detect poliovirus is extended from individuals to general populations (population sensitivity). Using the mathematical formulations for population sensitivity, the theoretical behavior of surveillance sensitivity under various conditions is analyzed. As a region nears the elimination of poliovirus, population sensitivity falls to a value lower than the case-to-infection ratio, regardless of the system proficiency. Also, a second stool specimen makes a substantial contribution to population sensitivity only in regions with relatively low specimen sensitivity and then only over a narrow range of population infection incidence. Estimates of the mean numbers of infected and uninfected acute flaccid paralysis cases investigated in a season are derived. These may serve as additional indicators of system operation but require the collection of 2 specimens per case.

Feces↗
PubMed1997

The experience of countries in the Western Pacific Region in conducting national immunization days for poliomyelitis eradication.

Experience with national immunization days (NIDs) in six countries of the Western Pacific Region has shown that political support at all levels, detailed logistics plans, strategies appropriate to the local situation, and simple social mobilization messages have been key factors in the success of NIDs. Conventional strategies that may apply to conducting routine Expanded Programme on Immunization vaccinations do not necessarily apply to NIDs, in which the maximum number of children must be immunized in 1 or 2 days. Setting up temporary immunization posts at sites convenient to the local situation, moving the posts once or twice during the course of a day, and using volunteers to staff them are among many of the adaptations used successfully. Coverage figures published immediately after an NID can be misleading because of uncertainty about the true denominator. The true measure of the success of NIDs is in surveillance for wild poliovirus after the event.

Asia, Southeastern↗
PubMed1997

Strengthening routine immunization services in the Western Pacific through the eradication of poliomyelitis.

Infant immunization coverage in the Western Pacific Region of the World Health Organization was reviewed to evaluate the impact of polio eradication activities on routine immunization services. The trend in bacille Calmette-Guérin (one dose; BCG), diphtheria-tetanus toxoids-pertussis (three doses; DTP3), and measles (one dose) vaccination rates was analyzed from the beginning of eradication activities in 1990 to 1994 in the five polio-endemic countries that conducted supplementary oral polio vaccine immunization. In China and the Philippines, coverage for each antigen remained at or above 90% and 85%, respectively, while in Vietnam, coverage for all three antigens rose from 85% to 95%. BCG, DTP3, and measles vaccine coverage more than doubled in the People's Democratic Republic of Lao and increased by >30% in the Kingdom of Cambodia during the same period.

Asia, Southeastern↗
PubMed1997

Neuropathy in non-freezing cold injury (trench foot).

Non-freezing cold injury (trench foot) is characterized, in severe cases, by peripheral nerve damage and tissue necrosis. Controversy exists regarding the susceptibility of nerve fibre populations to injury as well as the mechanism of injury. Clinical and histological studies (n = 2) were conducted in a 40-year-old man with severe non-freezing cold injury in both feet. Clinical sensory tests, including two-point discrimination and pressure, vibration and thermal thresholds, indicated damage to large and small diameter nerves. On immunohistochemical assessment, terminal cutaneous nerve fibres within the plantar skin stained much less than in a normal control whereas staining to von Willebrand factor pointed to increased vascularity in all areas. The results indicate that all nerve populations (myelinated and unmyelinated) were damaged, possibly in a cycle of ischaemia and reperfusion.

Adult↗
PubMed1996

The balance of prevention, investigation, and treatment in the management of child protection services.

The planning, development, and review of child protection services and policies (management) is vitally important and yet to date has received very little consideration. This paper explores the balance between three components of child protection policy: prevention, investigation, and treatment. As part of a review of the management of child protection services in Wales, the authors examined the effectiveness of Area Child Protection Committees (ACPCs), which are multidisciplinary forums responsible for the local provision of child protection services. Thirty-eight (of 171) representatives were interviewed. The balance of the three components (prevention, investigation, and treatment) in policy making was explored. Overall, there was a substantial emphasis on investigation procedures, with very little consideration of prevention strategies, and treatment services virtually ignored. Treatment was described as a "gap" in the service consideration of ACPCs. The authors consider ways to shift the balance so that treatment and prevention services can be given more priority within a comprehensive child protection service.

Child↗
PubMed1996

Anatomic goals in the correction of female stress urinary incontinence.

The goal of stress incontinence surgery is to prevent opening of the urethra during increases in intra-abdominal pressure. Greater refinements in the understanding of the pathophysiology of incontinence and experience with newer treatments have extended surgical thinking beyond the familiar paradigm "to place the urethra in a high retropubic position." When incontinence is associated with vaginal hypermobility, vaginal support may be sufficient to restore continence if the suburethral vaginal wall is sufficiently strong, an evaluation which must often be made by physical examination alone. However, when the vaginal wall is weak, the urethra will require an alternative form of support, usually a sling. If the urethra is intrinsically deficient, vaginal support may not be sufficient to prevent opening during increased intra-abdominal pressure, and coaptation by sling obstruction or periurethral bulking injection may be required. Most laparoscopic approaches to stress incontinence use Burch's method, which offers excellent urethral stability provided the suburethral vaginal wall is strong. Newer insights into the relation between vaginal mobility and urethral closure are discussed, as well as anatomic aspects of the Burch suspension relevant to laparoscopic repair.

Female↗
PubMed1996

Ipsilateral fractures of the femur and tibia: treatment with retrograde femoral nailing and unreamed tibial nailing.

Between 1989 and 1995 a total of 47 patients with 50 fractures of the ipsilateral femoral and tibial shafts without significant articular involvement were treated at Tampa General Hospital. Within this group were 24 patients with 26 fractures who were treated with intramedullary fixation of both bones using a technique of retrograde insertion of a femoral nail and unreamed insertion of an interlocking tibial nail. Information concerning the injuries, treatments, and much of the follow-up was gleaned from a trauma registry. Five of the femoral fractures (19%) and 14 of the tibial fractures (54%) were open. Associated injuries were present in 18 of the 24 patients (75%) with injuries of the pelvis, other extremities, and head being most prevalent. The average Injury Severity Score was 14 (range 9-32). The femoral nails were placed either through the medial femoral condyle (n = 14) or the intercondylar notch of the distal femur (n = 12). Twenty patients with 22 extremities had sufficient follow-up at an average of 20 months (range 4-60) postinjury to be included in the review. One patient had died, and three were completely lost to follow-up. Both fractures in 14 extremities had healed or were healing uneventfully at final review. Seven of the tibiae and three of the femora had complications after initial hospitalization. Two patients developed problems in both bones. Three patients had electrical stimulation of a tibia fracture, one of which underwent simultaneous nail dynamization. A total of 18 additional operative procedures were necessary after the primary treatment in six problematic extremities. Thirteen additional operative procedures were required in five complicated tibiae (one nail dynamization, six debridement procedures, five bone grafts, and one muscle flap) after the initial hospitalization. Five additional operative procedures were required in the three complicated femora (two nail dynamizations, one bone graft, and two exchange nailing procedures). Functional results were good or excellent in 13 of the 20 patients (65%) and 15 of the 22 extremities (68%) available at final review. No significant knee problem related to the femoral nailing technique was identified. This method of treatment can be performed using a standard radiolucent table and a single medial parapatellar incision. It is expedient and allows other procedures to be performed simultaneously in this group of severely injured patients.

Adolescent↗
PubMed1996

Trabeculectomy in the second eye.

Trabeculectomy has a reported success rate of between 67-94%. Many studies have been performed on operative variables which may influence surgical outcome. Youth, pigmented race and anterior segment inflammation have been shown to be associated with trabeculectomy failure. Little is known of the surgical outcome of trabeculectomy in one eye in relation to its partner, when surgery is standardized and the above known adverse conditions to trabeculectomy success are absent. We therefore carried out a prospective study on 62 patients who underwent bilateral trabeculectomies. There was a significant failure rate amongst pairs of eyes (postoperative intraocular pressure > or = 21 mmHg), with the majority of failures occurring within 6 months of surgery. Failure appeared to be associated with a longer period from diagnosis of glaucoma to surgery, and the use of a wider variety and number of topical medications. All other trabeculectomy complications occurred more commonly in any single eye, than in any pairs of eyes.

Aged↗
PubMed1996

Calcaneal malunions: results of a prognostic computed tomography classification system.

Following nonoperative treatment of calcaneal fractures, some patients may develop a disabling malunion with associated posttraumatic arthritis of the subtalar joint, impingement of the peroneal tendons, and hindfoot mal-alignment. We present a computed tomography classification system for calcaneal malunions which guides treatment and is of prognostic significance. A prospective study was performed using this classification system on a series of 26 malunions treated over a 45-month period. Three distinct types of malunions were identified: type I, lateral wall exostosis without subtalar arthrosis; type II, lateral wall exostosis with subtalar arthrosis; and type III, lateral wall exostosis, subtalar arthrosis, and a varus malunion. The surgical treatment was determined by a protocol based on the specific type of malunion encountered. Results were evaluated using the Maryland Foot Score. There were 18 excellent, 5 good, and 3 fair results. Although outcomes deteriorated as malunion complexity increased, significant clinical improvement as a result of reconstructive surgery was noted in even the worst types of malunion. This algorithm is consistent, prognostic, and useful for the orthopaedic surgeon presented with a symptomatic calcaneal malunion of one of these types.

Adult↗
PubMed1996

Ipsilateral fractures of the talus and calcaneus.

Nine ipsilateral fractures of the talus and calcaneus were treated at Tampa General Hospital between 1991 and 1994 and entered into the trauma registry of this level 1 trauma center. During this same period, a total of 78 talar fractures and 334 calcaneal fractures were entered into the registry. The patients who sustained this rare combined injury were studied retrospectively to characterize the fractures that occurred, examine the treatments instituted, and determine outcomes. Four patients had severe intra-articular damage of the subtalar joint surfaces and underwent either primary or delayed arthrodesis. This subgroup of patients was followed for an average of 39 months (range, 25-45 months), and all had excellent or good outcome as assessed by the Maryland Foot Score. Three patients had nondisplaced or avulsion-type fractures of both bones, which were treated with immobilization. These all healed well. One patient had a Hawkins type 2 talus fracture with an extra-articular avulsion fracture of the Achilles tendon. This patient did well with open reduction and internal fixation of both fractures. The final patient had a crushed lower extremity in association with her hindfoot injury, which resulted in primary below-knee amputation. In general, we believe each individual fracture in this combined injury can be addressed with standard treatment regimens.

Adult↗
PubMed1996

Hypospadias repair: the influence of postoperative care and a patient factor on surgical morbidity.

More than 200 surgical techniques have been advocated for hypospadias repair and perfection is still eluding us. The purpose of this paper is not to comment on a surgical technique, but to highlight the importance of postoperative care on the eventual surgical outcome. Two hundred six children undergoing primary hypospadias surgery from 1984 to 1994 at Mount Vernon Hospital were analyzed. The mean age of surgery was 3.8 years (range, 8 months-17 years) and our mean follow-up was 6.1 years. Various surgical techniques were used. During 1989, we changed our postoperative regime and patients were mobilized early (within 48 hours) compared to the strict-bed rest-till-catheter-out regime before 1988. This significantly reduced our fistula rate from 22% to 9.8% (chi squared p = 0.0016). Patient factors such as pulling on the catheter, urinary obstruction/blocked catheter, erections, straining due to constipation, and interference with dressings influence surgical outcome negatively. One of these patient factors was documented in all of our 33 patients who developed fistulas. In 6 patients (3.5%), a patient factor was present without any complication. This is highly significant statistically (chi squared p < 0.0001). The type of urinary diversion, period of urinary diversion, type of dressing, catheter size, and anesthetic regime did not influence outcome significantly.

Adolescent↗
PubMed1995

Quantitative pH imaging in cells using confocal fluorescence lifetime imaging microscopy.

The pH-sensitive probe carboxy SNAFL-1 can be used for imaging using ratiometric and fluorescence lifetime techniques. The former method suffers from the drawback that quantitative pH imaging in cells requires a time-consuming and cumbersome calibration procedure. In contrast, straightforward calibrations in buffer suffice for fluorescence lifetime imaging. This is illustrated here by a comparative study of the two techniques under different controlled conditions. The effect of probe concentration, protein concentration, and hydrophobicity, the contents of damaged cells and living cells on the emission ratio, and the fluorescence lifetime of carboxy SNAFL-1 were studied. The results clearly demonstrate that the fluorescence lifetime imaging technique is more convenient than the ratiometric method for pH determination.

Animals↗
PubMed1995

Molecular cloning, characterization, and chromosomal localization of a human lymphoid tyrosine kinase related to murine Blk.

Triggering of Ag receptors on lymphocytes induces rapid phosphorylation of several receptor-associated protein tyrosine kinases (PTKs), implicating their role in controlling cellular growth and differentiation. In this study, we report the cloning of a human cDNA encoding a nonreceptor PTK with a calculated M(r) of about 58 kDa. The kinase has an overall amino acid identity of approximately 87% with the murine Blk. However, in the unique domain there is only 58% homology and an insertion of six amino acids in the N-terminal region. The nature of this insertion suggests a functional role in membrane attachment. Northern blot analysis showed expression in all stages of B cell development and in T cell lines. The message was not observed in the nonlymphoid tissues examined. In contrast, expression of murine blk in plasma cells and T lymphocytes has not been reported. Importantly, transcripts were seen in human embryonic liver as early as 7.5 wk of gestation before the rearrangement of Ig H chain locus. Furthermore, transcripts were detected in human thymocytes and not in mature T cells. Southern blot analysis revealed polymorphism of this gene in a Caucasian population but not in a Gambian population, indicating a recent origin of this polymorphism. The gene was localized to chromosome 8p22-23. The homology at the protein level suggests that this kinase may be the human homologue of murine Blk. Expression of BLK in immature T cells suggests that BLK may play an important role in thymopoiesis.

Amino Acid Sequence↗
PubMed1995

Treatment of fractures and dislocations of the thoracic and lumbar spine by fusion and Harrington instrumentation.

Thirty-three patients with fractures of the thoracolumbar spine were treated by fusion and Harrington instrumentation after early reduction and stabilisation by postural reduction or halo-bifemoral traction. The rod-long-fuse-short technique was used. Postoperatively, all patients were mobilised with an external support. The mean follow-up was 6 years (range 1-13 years). Twenty-eight patients were pain-free, three patients needed sporadic pain medication. One patient was not working due to pain in his leg. One patient had constant pain. Twenty-three patients returned to work. The mean kyphosis increased from 8 degrees postoperatively to 13 degrees at follow-up.

Adolescent↗
PubMed1995

Transplantation of keratinocytes in the treatment of wounds.

BACKGROUND: Keratinocyte grafting can be used to treat acute traumatic and chronic non-healing wounds. The keratinocyte sheets are fragile and clinical "take" is difficult to assess, especially as activated keratinocytes secrete many growth factors, which have effects on wound healing apart from take. We have developed animal models of grafting that allow us to examine factors influencing autologous keratinocyte graft take. Results show clearly that pretreatment of the wound bed with viable dermis greatly increases the take of keratinocyte grafts. DATA SOURCES: International literature. CONCLUSIONS: As a greater understanding of the complex interactions of cell and matrix evolve, so will potential therapeutic maneuvers, not just in the field of cultured keratinocyte grafts, but clearly in that of benign tumors, for example, keloids, and that of oncology. There is now overwhelming evidence of the requirement for a dermal substitute for cultured keratinocyte autografts, and the sheet complexity of the situation demands that this should approximate live human dermis as closely as possible. The stumbling blocks relate to avoiding the risks of viral transmission, tissue matching of host and donor, providing early epithelial cover, and improving delivery systems for fragile keratinocyte grafts.

Animals↗
PubMed1995

Intraoperative somatosensory evoked potential monitoring during acute pelvic fracture surgery.

Independent clinical neurological evaluation and intraoperative somatosensory evoked potential (SSEP) monitoring was performed on 30 vertically unstable hemipelvis fractures in 28 patients undergoing acute open reduction and internal fixation. Preoperative ipsilateral neurologic injury of the sciatic/lumbosacral plexus was noted in 15 of 30 fractures (50%). Significant unilateral SSEP changes occurred during manipulative reduction of two displaced sacroiliac joints and one sacral fracture. Because of the expeditious response of the surgical team, with release of traction/retraction, SSEP returned to baseline and no patient sustained an iatrogenic nerve injury or worsening of their preoperatie neurologic status. The incidence of postinjury lumbosacral plexopathy in unstable pelvic fractures is high (50%) when careful preoperative evaluation including SSEP is performed. The use of intraoperative SSEP monitoring is feasible in acute posterior pelvic fracture surgery and can help identify potential intraoperative iatrogenic lumbosacral neurological compromise.

Adolescent↗