Search Results - (Author, Cooperation:A. J. Millar)

2012-03-10

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Arabidopsis/genetics/*physiology ; Arabidopsis Proteins/chemistry/genetics/*metabolism ; Chromatin Immunoprecipitation ; *Circadian Clocks/genetics ; DNA-Binding Proteins/genetics/metabolism ; Darkness ; Dexamethasone/pharmacology ; Feedback, Physiological ; *Gene Expression Regulation, Plant ; Genes, Plant ; Light ; Photoperiod ; Plants, Genetically Modified ; Promoter Regions, Genetic ; RNA Interference ; Repressor Proteins/genetics/*metabolism ; Transcription Factors/chemistry/genetics/*metabolism ; Transcription, Genetic

2012-05-26

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Arabidopsis/genetics/growth & development/metabolism/*physiology ; Arabidopsis Proteins/chemistry/*genetics/*metabolism ; DNA-Binding Proteins/genetics/*metabolism ; Flowers/*growth & development ; Gene Expression Regulation, Plant ; Light ; Models, Biological ; Mutation ; *Photoperiod ; Plants, Genetically Modified ; Promoter Regions, Genetic ; Protein Binding ; Protein Interaction Domains and Motifs ; Protein Stability ; RNA, Messenger/genetics/metabolism ; RNA, Plant/genetics/metabolism ; Repressor Proteins/metabolism ; Transcription Factors/genetics/*metabolism ; Transcription, Genetic

2011-01-29

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Biomarkers/analysis ; Chlorophyta/drug effects/metabolism/*physiology ; Circadian Rhythm/*physiology ; Cycloheximide/pharmacology ; Deoxyadenosines/pharmacology ; Gene Expression Regulation/drug effects ; Oxidation-Reduction ; Peroxiredoxins/metabolism ; Protein Synthesis Inhibitors/pharmacology ; *Transcription, Genetic

2012-05-25

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Amino Acid Sequence ; Animals ; Archaea/metabolism ; Bacteria/metabolism ; Biomarkers/metabolism ; Catalytic Domain ; Circadian Clocks/genetics/physiology ; Circadian Rhythm/genetics/*physiology ; *Conserved Sequence ; Eukaryotic Cells/metabolism ; *Evolution, Molecular ; Feedback, Physiological ; Homeostasis ; Humans ; Models, Biological ; Molecular Sequence Data ; Oxidation-Reduction ; Peroxiredoxins/chemistry/*metabolism ; Phylogeny ; Prokaryotic Cells/metabolism ; Protein Biosynthesis ; Transcription, Genetic

1077-3118

AIP Digital Archive

Physics

We describe a direct-current superconducting quantum interference device (SQUID) first-order gradiometer fabricated from a single layer of YBa2Cu3O7 on a 30×10 mm2 bicrystal substrate. The device has a baseline of 13 mm and an intrinsic balance of ∼10−3. The gradient sensitivity at 77 K and 1 kHz is 50 fT/(cmHz) in magnetic shielding and 260 fT/(cmHz) when operated unshielded in our laboratory. An antiparallel two-SQUID coupling scheme is employed to optimize the device's balance to at least 3×10−5. © 1999 American Institute of Physics.

Electronic Resource

1077-3118

AIP Digital Archive

Physics

We describe a first-order gradiometric dc superconducting quantum interference device (SQUID) and its incorporation into a first-order directly coupled single-layer gradiometer. The gradiometric SQUIDs were fabricated from a single layer of YBa2Cu3O7, with a silicon dioxide insulating layer and a gold crossover structure. For several gradiometric SQUIDs, with estimated inductances of order 67 pH, we measured parasitic effective areas in the range 1–2 μm2, approximately two orders of magnitude lower than for conventional narrow linewidth SQUIDs of similar inductance. For a single-layer gradiometer incorporating a gradiometric SQUID, we measured a parasitic effective area of 95 μm2. We demonstrate that for this device, the SQUID itself makes a negligible contribution to the overall parasitic effective area. We show that the improved balance leads to better performance in an unshielded environment. © 2000 American Institute of Physics.

Electronic Resource

1432-1998

Springer Online Journal Archives 1860-2000

Medicine

Abstract Selective bronchial intubation and lavage under fluoroscopic control was performed in 10 surgical neonates and infants to clear lobar atelectasis, after standard physiotherapeutic techniques had failed. Full re-expansion of the lung was obtained in all cases. The indications and techniques of selective bronchial intubation and lavage are described. This manoeuvre can be recommended in early postoperative atelectasis in neonates and infants if non-invasive measures have failed.

Electronic Resource

1432-1998

Springer Online Journal Archives 1860-2000

Medicine

Abstract Pyogenic liver abscesses are not infrequent in some developing countries. Amoebic abscesses may also occur in endemic areas and differentiation may be difficult. The ultrasonic data of proven cases of both conditions were compared and we are now more more confident in predicting the aetiology of these lesions.

Electronic Resource

1437-9813

Neonatal tumours ; Neonatal malignancy ; Long-term follow-up ; Genetic ; Complications

Springer Online Journal Archives 1860-2000

Medicine

Abstract Sixty-six solid neoplasms occurring in neonates treated at the Red Cross Childrens Hospital over a 34-year period (1957–1991) were reviewed and recalled for long-term follow-up (mean 10.4 years). Associated congenital abnormalities were rare, but chromosomal abnormalities were detected in 3 patients, one of which was familial. Teratomatous germ-cell tumours predominated, followed by neuroblastomas and soft-tissue tumours; 23 had malignant morphologic appearances and 43 were morphologically non-malignant. Seventy-nine per cent presented within the 1st week of life, 41% of these within the first 24 h. Although most sacrococcygeal teratomatous germ-cell tumours were benign, malignancy was present in 2 patients (1 of these presented during the 1st week of life). A further 11 sacrococcygeal teratomas were found on light microscopy to include immature elements and had unpredictable clinical behaviour; 2 of these later metastasized despite adequate surgical clearance. All 4 patients with mesoblastic nephromas and 1 with a neonatal Wilm's tumour survived. In addition, 6 of the 10 patients with a neuroblastoma survived long-term. One of 3 patients with a rhabdomyosarcoma survived as well as 1 of 2 with a hepatoblastoma. Congenital fibrosarcomas, although morphologically aggressive, had an excellent outcome. Surgical excision was performed in all cases, and overall patient survival on long-term follow-up was 66% (44 patients). These survivors included 10 (41%) of those with malignant tumours and 24 (84%) with potentially malignant tumours. Metastatic spread or secondary tumours were shown to occur at variable stages, and early, frequent, and regular follow-up is recommended. Complications of extensive surgery resulted in 3 temporary and 2 long-term problems. Other adverse effects of therapy were observed in survivors of chemo- or radiation therapy, where poor growth was noted in 9 (82%), behavioural disturbances in 3 (27%), and intellectual impairment in 4 (36%).

Electronic Resource

1437-9813

Key words Conjoined twins ; Evaluation ; Surgical separation

Springer Online Journal Archives 1860-2000

Medicine

Abstract  This paper records our experience in the management of 25 sets of conjoined twins seen over a 32 year period (1964 – 1996). The twins were classified into 14 complete and symmetrical sets and 11 incomplete or heteropagus. The 14 symmetrical sets included 9 thoracopagus, 2 ischiopagus, 1 craniopagus and 1 omphalopagus twins. In the incomplete heteropagus group there was 1 ischiopagus, one twin being anencepahlic, 2 dipygus, 5 parasitic, 2 fetus-in-fetu and I cranial and caudal. The management is detailed case by case. Overall 10 of 14 symmetrical sets underwent attempts at separation with 16 surviving the procedure, but there were 3 late deaths. In the incomplete group 10 of 11 were operated on with 9 survivors. The importance of a multi-disciplinary approach, the extensive investigations required pre-operatively to define areas of organ and bony conjuction, congenital anomalies of each twin and surgical teamwork is emphasized. Specific problems encountered were indentified. In thoracopagus twins the hearts were of paramount importance as conjuction was usually fatal, being associated with major congenital defects. The greater the extent of thoracic cage fusion the greater the chance of associated severe anomaly. Skin expansion to assist coverage of the defects after separation was of great assistance, as was the use of collagen coated vicryl. Evaluation of the liver and pancreatico-biliary systems with isotope excretion scanning was crucial to pre-operative planning. Where there was fusion of the duodenum a single pancreatico-biliary system could be expected and prior strategies for separation and Roux-en-Y enteric drainage of both pancreatic and biliary secretion should be planned. Gastro-oesophageal reflux led to considerable morbidity in both twins of a thoraco-omphalopagus set. In ischiopagus and dipygus conjoined twins bilateral posterior iliac osteotomies were an essential component to anatomic reconstruction of the pelvic ring and wound closure. Also in this group, due to the frequency and extent of shared genital, urinary and ano-rectal structures, long-term morbidity was expected and a component of this might be due to spinal cord tethering, or as in one of our cases, a progressive hydrosyringomyelia. Timing of separation was ideally set at between 5 and 9 months with 6 to 8 weeks of prior tissue expansion but earlier operation was frequently required because of cardio-respiratory problems or organ failure in one twin. In most cases the goal of obtaining separate, independant and intact individuals was achieved.

Electronic Resource

1437-9813

Key words Burns ; Inhalation injury ; Children

Springer Online Journal Archives 1860-2000

Medicine

Abstract Survival from serious burns in children has improved substantially in recent years. Mortality is predominantly determined by the total body surface area burned and the often unrecognised inhalation injury. A retrospective review of 4,451 consecutive children with thermal injuries over a 10-year period was undertaken to determine the incidence, clinical presentation, and pathology of inhalation injury and its contribution to morbidity and mortality. Inhalation burns were diagnosed clinically and confirmed endoscopically and post-mortem in 97 (2.2%) children; 77 sustained fire burns (mean age 4 years) and 20 hot-water burns (mean age 18 months). The Moylan classification stratified them into upper-airway burns in 59 children, major–airway burns in 29, and parenchymal burns in 44. Major-airway burns were always seen in conjunction with either upper-airway or parenchymal injury. Stridor and acute progressive respiratory distress were the two main symptoms, the onset of which was occasionally delayed for up to 72 h. Endoscopy was most helpful in confirming the diagnosis and determining airway management. Endotracheal intubation was needed in more than 50% of children, usually for less than 5 days, and was converted to tracheostomy in only 6. Persistent laryngeal and tracheal damage was identified in 4. Secondary pneumonia occurred in 41.5% of children with fire burns and 55% with hot-water burns. Extensive surface burns, parenchymal injury, and secondary pneumonia all contributed to the significant mortality. Post-mortem findings corroborated clinical and endoscopic evidence. This study suggests that inhalation burns were often not recognised, could present late, and usually had significant consequences. Early clinical diagnosis, supported by endoscopic findings and appropriate management, is essential if the high morbidity and mortality amongst these children is to be improved.

Electronic Resource

1437-9813

Malrotation ; Midgut volvulus ; Children

Springer Online Journal Archives 1860-2000

Medicine

Abstract 137 cases of malrotation and midgut volvulus seen over a 28-year period are reviewed to emphasize the patterns of clinical presentation. Although 62% presented as neonates, 20% were over 1 year of age. Vomiting was the sympton of paramount importance in 97% but was not initially bile-stained in 20%. Sixteen percent had diarrhea as a major symptom. Abdominal pain occurred in 96% of patients over 1 year of age. Clinical signs were not apparent in most cases until gut infarction had occurred. Radiographic examination of the abdomen was considered normal in more than 20%. Barium meal was the contrast examination with most accuracy and should be diagnostic if correctly interpreted. The significant mortality (19%) in all age groups was invariably related to delay in presentation or diagnosis.

Electronic Resource

1437-9813

Hirschsprung's disease ; Aganglionosis ; Intestinal atresia ; Myelomeningocoele

Springer Online Journal Archives 1860-2000

Medicine

Abstract Intestinal atresia associated with Hirschsprung's disease has been reported in only 26 cases (20 of small bowel and 6 of colon). Three additional patients are reported, two with associated myelomenigocoele. The significance of the myelomeningocoele and possible aetiological mechanisms of these associations are discussed with particular reference to the role of a vascular accident or the embryological failure of migration of nerve cells. The most likely cause is a volvulus proximal to the aganglionic bowel resulting in the associated atresia.

Electronic Resource

1437-9813

Lye ; Oesophageal strictures ; Colonic interposition

Springer Online Journal Archives 1860-2000

Medicine

Abstract In a series of 142 children treated for corrosive burns at the University of Cape Town teaching hospitals between 1957 and 1990, 55 developed strictures of the oesophagus. Prograde dilatations with or without a guiding trans-stricture string proved successful in 22 children while 33 had an oesophageal bypass procedure. The complications following dilatations, particularly the 10 perforations of the oesophagus, are reviewed. Three of these later responded successfully to further dilatations. Since 1969, a single-staged left colon interposition was employed as the procedure of choice. The operative technique of the left colon interposition is described and the early and late complications following the bypass procedures are detailed and discussed, stenosis and strictures at the upper anastomosis being the most significant.

Electronic Resource

1437-9813

Conjoined twins ; Evaluation ; Surgical separation

Springer Online Journal Archives 1860-2000

Medicine

Abstract This paper records our experience in the management of 25 sets of conjoined twins seen over a 32 year period (1964–1996). The twins were classified into 14 complete and symmetrical sets and 11 incomplete or heteropagus. The 14 symmetrical sets included 9 thoracopagus, 2 ischiopagus, I craniopagus and 1 omphalopagus twins. In the incomplete heteropagus group there was I ischiopagus, one twin being anencepahlic, 2 dipygus, 5 parasitic, 2 fetus-in-fetu and I cranial and caudal. The management is detailed case by case. Overall 10 of 14 symmetrical sets underwent attempts at separation with 16 surviving the procedure, but there were 3 late deaths. In the incomplete group 10 of 11 were operated on with 9 survivors. The importance of a multi-disciplinary approach, the extensive investigations required pre-operatively to define areas of organ and bony conjuction, congenital anomalies of each twin and surgical teamwork is emphasized. Specific problems encountered were indentified. In thoracopagus twins the hearts were of paramount importance as conjuction was usually fatal, being associated with major congenital defects. The greater the extent of thoracic cage fusion the greater the chance of associated severe anomaly. Skin expansion to assist coverage of the defects after separation was of great assistance, as was the use of collagen coated vicryl. Evaluation of the liver and pancreatico-biliary systems with isotope excretion scanning was crucial to pre-operative planning. Where there was fusion of the duodenum a single pancreatico-biliary system could be expected and prior strategies for separation and Rouxen-Y enteric drainage of both pancreatic and biliary secretion should be planned. Gastro-oesophageal reflux led to considerable morbidity in both twins of a thoraco-omphalopagus set. In ischiopagus and dipygus conjoined twins bilateral posterior iliac osteotomies were an essential component to anatomic reconstruction of the pelvic ring and wound closure. Also in this group, due to the frequency and extent of shared genital, urinary and ano-rectal structures, long-term morbidity was expected and a component of this might be due to spinal cord tethering, or as in one of our cases, a progressive hydrosyringomyelia. Timing of separation was ideally set at between 5 and 9 months with 6 to 8 weeks of prior tissue expansion but earlier operation was frequently required because of cardio-respiratory problems or organ failure in one twin. In most cases the goal of obtaining separate, independant and intact individuals was achieved.

Electronic Resource

1437-9813

Radiation enteritis ; Children

Springer Online Journal Archives 1860-2000

Medicine

Abstract Six children with intestinal radiation injury following cancer therapy are presented. The radiation dose varied from 3500 rads to 6600 rads. Symptoms of radiation enteritis took from 3 weeks to 3 years to develop. All patients received concomitant chemotherapy. Incomplete bowel obstruction was the most common presenting feature (four cases); five came to laparotomy. Simple adhesiolysis was successful in two cases; two children required more extensive surgical manoeuvres (small-bowel bypass and bowel resections). All are alive and well 4 to 13 years following therapy although five have other radiation effects. Radiation injury to the bowel and its management are discussed.

Electronic Resource

1437-9813

Oesophagus ; Stricture ; Dilatation ; Children

Springer Online Journal Archives 1860-2000

Medicine

Abstract Very narrow oesophageal strictures, although visible on contrast examination, may not be amenable to safe prograde dilatation. A technique used in four recent cases where attempts at prograde dilatation had failed is described. The strictures were easily negotiated from below via a gastrostomy and the distal oesophagus using an Arrow Duoflex guide wire for subsequent string-guided dilatation. Access to the lower oesophagus was easily achieved using a Portex blue-line endotracheal tube. This method appears quick, safe, and reliable.

Electronic Resource

1437-9813

Vestibular fistula ; Fistula trasplant ; Posterior sagittal anorectoplasty

Springer Online Journal Archives 1860-2000

Medicine

Abstract Eleven females who had a posterior anal transfer (PAT) for a vestibular anus were reviewed in order to: (1) assess the long-term functional success of this operation clinically; (2) evaluate the anorectal manometry profile; and (3) assess defaecation by video proctography. The cosmetic appearance was excellent in all patients. Seven had a good result, 2 a fair result, and 2 a poor result when assessed clinically (Kelly score) in terms of constipation and soiling. The anorectal manometry profile remained within normal limits except in the 2 with a poor result who had diminished sensory awareness of stool in the rectum. PAT does not appear to damage the muscle-sphincter complex, and the children with a large rectum full of faeces seemed to behave like children with acquired megacolon and constipation. Video proctography showed normal defaecatory patterns in all patients. Patient selection is important for this procedure. When PAT was used as the initial treatment a good result was obtained; when it was used to relieve constipation following previous surgery the result was less satisfactory.

Electronic Resource

1437-9813

Meckel's diverticulum ; Diagnosis ; Technetium scan

Springer Online Journal Archives 1860-2000

Medicine

Abstract A retrospective study was conducted of our experience with sodium pertechnetate Tc99m scans for diagnosing suspected Meckel's diverticula. Seventy-seven cases scanned between 1979 and 1994 were reviewed. Eighty per cent of the group presented with bleeding per rectum, 12% with pain, and 6.5% with anaemia. Ten scans were positive with 7 true-positive and 3 false-positive. Of the 67 negative scans, 3 were false-negatives. There were six Meckel's diverticuli and four duplication cysts between the true-positive and false-negative groups. All presented with major gastrointestinal (GI) bleeding and gastric mucosa was identified on histology. The three false-positive cases had inappropriate laparotomies on the basis of scan results. The test sensitivity was 70% with a specificity of 95%, giving an overall accuracy of 92%. The Meckel's scan is a useful investigation for GI bleeding in children. Surgical intervention should be guided by the full clinical picture and the scan, rather than the scan result alone.

Electronic Resource

1437-9813

Key words Children ; Corrosive oesophageal stricture ; Indications for oesophageal replacement

Springer Online Journal Archives 1860-2000

Medicine

Abstract The accidental ingestion of corrosive agents is a major cause of oesophageal strictures in children. The mainstay of treatment is repeated dilatations. Despite this, a significant number of patients eventually require oesophageal bypass. We reviewed the records of all cases managed with this condition at the University of Cape Town teaching hospitals between 1976 and 1994. Dilatation therapy alone was successful in 14 out of 39 patients (41%). Morbidity of failed dilatation therapy included repeated hospital admissions over an average 11.5 months and 17 dilatations each. Oesophageal perforations occurred in 7 cases (18%). Early factors predictive of failure of conservative treatment were: delay in presentation of more than 1 month; severe pharyngo-oesophageal burns requiring a tracheostomy; oesophageal perforation; and a stricture longer than 5 cm on radiological assessment. The size of dilators accepted during early bougienage also correlated with eventual outcome. These criteria may be useful in predicting which patients will not respond to repeated dilatations. Early surgical intervention in such cases will prevent fruitless dilatations and related complications.

Electronic Resource