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Biomedical subjects

R Alexander

Publications and source records attributed to R Alexander.

At least 19 recordsLinked to original sources
PubMed1995

Comparison of different methods of administering droperidol in patient-controlled analgesia in the prevention of postoperative nausea and vomiting.

We performed a double-blind, placebo-controlled study to evaluate the different methods of administering droperidol in patients using patient-controlled analgesia (PCA) with morphine. Eighty patients undergoing major orthopedic procedures received temazepam 0.2 mg/kg orally followed by induction of general anesthesia with propofol 2.5 mg/kg, fentanyl 2 micrograms/kg, and vecuronium 0.1 mg/kg. Anesthesia was maintained with nitrous oxide, oxygen, and enflurane. At the end of surgery, all patients received PCA with morphine (0.5 mg/mL, bolus dose 1 mg, and lockout interval 5 min. Before commencement of PCA, patients were randomized to receive droperidol 1.25 mg immediately and, in addition, droperidol 0.16 mg with each PCA dose (Group 1), droperidol 1.25 mg immediately (Group 2), droperidol 0.16 mg with each PCA dose (Group 3), and no droperidol (Group 4). Incidence of nausea and vomiting, request for rescue antiemetics, sedation score, and side effects were recorded every 4 h. Droperidol significantly reduced the incidence of postoperative nausea and vomiting (PONV) (P < 0.01) and request for rescue antiemetic (P < 0.01) compared to placebo. However, there was no difference in the incidence of PONV between droperidol given either as a single dose at the end of surgery (Group 2) or mixed in morphine PCA (Group 3). The addition of droperidol in PCA after an initial dose (Group 1) should be avoided, as it resulted in more sedation and no further reduction in the incidence of PONV compared to Groups 2 and 3.

Adolescent↗
PubMed1995

Overuse injuries in classical ballet.

Successful management of classical ballet dancers with overuse injuries requires an understanding of the art form, precise knowledge of anatomy and awareness of certain conditions. Turnout is the single most fundamental physical attribute in classical ballet and 'forcing turnout' frequently contributes to overuse injuries. Common presenting conditions arising from the foot and ankle include problems at the first metatarsophalangeal joint, second metatarsal stress fractures, flexor hallucis longus tendinitis and anterior and posterior ankle impingement syndromes. Persistent shin pain in dancers is often due to chronic compartment syndrome, stress fracture of the posteromedial or anterior tibia. Knee pain can arise from patellofemoral syndrome, patellar tendon insertional pathologies, or a combination of both. Hip and back problems are also prevalent in dancers. To speed injury recovery of dancers, it is important for the sports medicine team to cooperate fully. This permits the dancer to benefit from accurate diagnosis, technique correction where necessary, the full range of manual therapies to joint and soft tissue, appropriate strengthening programmes and maintenance of dance fitness during any time out of class with Pilates-based exercises and nutrition advice. Most overuse ballet conditions respond well to a combination of conservative therapies. Those dancers that do require surgical management still depend heavily on ballet-specific rehabilitation for a complete recovery.

Ankle Injuries↗
PubMed1994

A novel embryo-specific barley cDNA clone encodes a protein with homologies to bacterial glucose and ribitol dehydrogenase.

In order to analyze the genetic programme expressed during the early stages of embryogenesis a cDNA clone bank was constructed from desiccation-tolerant excised barley embryos 18 d after pollination (D. Bartels et al., 1988, Planta 175, 485-492). One of the selected cDNA clones pG31 encodes a transcript of 1300 nucleotides and a protein of 31 kDa, both are specifically expressed in developing embryos and are not detected in other tissues. The expression of the pG31 mRNA is not modulated by the plant hormone cis-abscisic acid but it ceases to be expressed in germinating embryos. The protein sequence deduced from the pG31 transcript shows substantial sequence homologies to bacterial glucose dehydrogenase and ribitol dehydrogenase. Biochemical analysis indicates that glucose dehydrogenase activity is present in protein extracts from embryos 18 d after pollination. This glucose dehydrogenase activity is inhibited by antiserum raised against the recombinant pG31 protein. These findings provide evidence for the discovery of a novel pathway in carbohydrate metabolism acting specifically during embryogenesis.

Amino Acid Sequence↗
PubMed1994

Early identification and treatment necessary to prevent malnutrition in children and adolescents with severe disabilities.

Children with severe developmental disabilities frequently have nutrition and growth problems that range from moderate to severe. Because of notable continuing medical concerns and lowered growth expectations, parents and physicians may fail to recognize gradual deterioration in nutritional status before severe medical complications occur. The two cases reported in this article illustrate the need for early identification and treatment to prevent the development of notable morbidity secondary to malnutrition. Children and adolescents who have growth parameters consistently below age norms require assessment and monitoring by a registered dietitian to detect feeding problems and intake changes and to provide early intervention to help prevent negative consequences (eg, dehydration, protein-energy malnutrition, decubitus ulcers, increased rate and duration of infections, and altered bowel motility). An initial assessment should consist of measurement of length or height, weight, triceps, and subcapsular skinfolds; dietary and feeding history and a review of medical history; and biochemical testing as indicated by the medical and dietary histories. Monitoring frequency, which is determined by age, severity of condition, and response to treatment, may vary from weekly to bimonthly.

Adolescent↗
PubMed1992

The synchronization of ventilation and locomotion in horses (Equus caballus).

Ciné film and synchronized records of respiratory flow were obtained from Thoroughbred racehorses cantering on a treadmill at speeds of 9 and 11 m s-1. Horses and some other galloping and hopping mammals link their breathing and locomotion, taking exactly one breath per stride. Three theoretical mechanisms by which the movements of locomotion might drive ventilation are considered. (i) Flexion of the lumbosacral joint and the resulting forward sweep of the pelvis pushes the viscera against the diaphragm. However, back flexion lags behind ventilation at 11 m s-1 and could not exclusively drive ventilation at this speed. (ii) Loading of the thorax by the impact of the forelimbs with the ground might force air out of the lungs. If the respiratory system were damped sufficiently to perform as this mechanism requires, the work of driving ventilation would make up approximately 15% of the total work of running. In comparison with other estimates of the work of ventilation this seems improbably high. (iii) The observed phase relationship between displacements of the viscera, caused by the accelerations of the body during running, and respiratory airflow is not consistent with a tuned visceral piston mechanism driving breathing. Thus, it would seem likely that back flexion is likely to contribute towards driving ventilation but loading of the thorax and the visceral piston mechanism do not.

Animals↗
PubMed1992

The use of hepatobiliary scintigraphy in patients with acalculous biliary colic.

Twelve patients with biliary colic had no evidence of gallstones but underwent cholecystokinin-augmented hepatobiliary scintigraphy that revealed gallbladder ejection fractions of less than 35%. All 12 patients underwent cholecystectomy. Biliary colic was relieved in all patients at a mean postoperative follow-up of 2.5 years. The biliary colic in these patients was probably caused by abnormal gallbladder emptying, itself apparently produced by either cystic duct obstruction or abnormal motility. Biliary abnormality was seen at operation in most patients, and all patients had abnormalities of the gallbladder or cystic duct seen grossly or histologically. These abnormalities included cystic duct stenosis or adhesions, chronic inflammation, and cholesterolosis.

Adult↗
PubMed1990

Serial abuse in children who are shaken.

Serious injury can occur to children who are shaken, especially if the shaking is repeated or part of a pattern of abuse. Serial abuse in connection with children who are shaken and their siblings has important therapeutic and legal ramifications. From an ongoing study of child abuse and head trauma, 12 of 24 victims of shaking that resulted in intracranial injury were identified who had coexisting evidence of direct external trauma. Seventeen children (71%) had evidence of prior abuse, neglect, or both, including 8 who had multiple intracranial hemorrhages. Of the 21 families represented, 9 had more than one child, 3 (3%) of which had several siblings who had been victims of child abuse. Shaking of children usually is not an isolated event, as it frequently has been preceded by other types of abuse.

Brain Injuries↗
PubMed1990

Incidence of impact trauma with cranial injuries ascribed to shaking.

Shaking as a mechanism of severe brain injury in infants has been challenged on a theoretical basis as insufficient to explain the magnitude of observed injuries. Computed tomography and magnetic resonance imaging, developed since shaken baby syndrome was first described, are helpful in establishing whether external trauma occurred for infants thought to have been shaken. We compiled data from 24 infants initially diagnosed as having shaken baby syndrome, including physical examination, roentgenograms, computed tomography or magnetic resonance imaging, and autopsy (when applicable). Half of the patients showed no evidence of direct impact, and evidence of external trauma was not predictive of a fatal outcome. These findings indicate that shaking by itself is sufficient to cause severe or fatal intracranial injury and that the shaken baby syndrome reflects a spectrum of such child abuse injuries that may include direct trauma or only shaking.

Brain Injuries↗
PubMed1990

The validity of self-reported abstinence and quality sobriety following chemical dependency treatment.

The validity of self-reports from 171 former patients at a 28-day inpatient treatment program was examined by comparing self-report measures of abstinence and current life functioning with concurrent reports by significant others. Strong convergent validation was found, with 92% of significant others agreeing with the self-reports of the former clients. The "quality of sobriety" measures of familial, occupational, social, and emotional adjustment were studied and validated by the convergent validation technique. Discussed is the value of convergent validation in terms of both follow-up success rates and program evaluation. Methodological concerns and resulting limitations of the data are reviewed.

Adult↗
PubMed1990

Serial Munchausen syndrome by proxy.

Five cases of Munchausen syndrome by proxy (MSBP) are presented in which more than one child in the family was victimized. There was a high incidence of maternal psychiatric histories, marital difficulties, and Münchhausen syndrome in the mothers themselves. Seventy-one percent of the children in the families were known to be victims of MSBP; four of these children (31%) died. Multiple-child MSBP may reflect more significant maternal psychopathology than found in other cases of MSBP, or it may indicate the deteriorating consequences to the mother and other children in the family if this syndrome is not identified with the first child and effective interventions made.

Apnea↗
PubMed1990

Munchausen syndrome by proxy presenting as a developmental disability.

Munchausen syndrome by proxy (MSBP) is a form of child abuse in which a parent falsifies illness in a child by fabricating or producing symptoms and presenting the child for medical care while disclaiming knowledge as to the cause of the problem. This report presents the case history of a child diagnosed with MSBP who was portrayed as having multiple developmental disabilities by her mother. Three elements of the case are noteworthy. The emphasis by the mother on multiple developmental disabilities has not been reported. The complexity of this case is unusual and may reflect the complexity of the mother's psychopathology. The interdisciplinary team evaluation was instrumental in making the diagnosis.

Cerebral Palsy↗