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Biomedical subjects

F M Anderson

Publications and source records attributed to F M Anderson.

At least 19 recordsLinked to original sources
PubMed2000

Synthesis of new homochiral bispyrrolidines as potential DNA cross-linking antitumour agents.

We are seeking to develop more effective bifunctional alkylating agents as antitumour agents. We previously synthesized conformationally restricted nitrogen mustards containing one piperidine ring, then bispiperidine derivatives were designed and prepared with varying lengths of carbon chain between the two rings and structure-activity relationships in these systems were studied. A bispiperidine with the shortest bridge of two carbon atoms was the most reactive bifunctional alkylating agent. In order to extend this work and investigate the effects of a change in the size of the heterocyclic systems, new bispyrrolidine salts 17-23 with chloromethyl groups at the 2-positions and a bridge between the two nitrogen atoms of 2-8 carbon atoms were synthesized from L-proline so that only the LL-enantiomers were produced. The free bases were designed to be bifunctional alkylating agents via aziridinium ion formation with different distances between the two alkylating sites. All of the bispyrrolidines were efficient cross-linkers of naked DNA apart from those with three-carbon (18) and four-carbon (19) bridges, in contrast to the results with the bispiperidines. A piperazine derivative 24 with two potential alkylating sites was also shown to be an efficient cross-linker, as was an alicyclic compound 25 with six carbon atoms between the two alkylating sites. Compounds 26 and 30 with an extra carbon atom between the nitrogen and the leaving group were not cross-linkers, as expected if aziridinium ion formation is crucial for cross-linking ability. The preformed aziridine 27 with a further alkylating site was an efficient cross-linker. Compounds 28-29 with only one potential alkylating centre were not cross-linkers of DNA. None of the compounds, however, produced significant cytotoxicity in human tumour cells in vitro.

Amines↗
PubMed1992

Surgical face masks are effective in reducing bacterial contamination caused by dispersal from the upper airway.

We have studied the effectiveness of surgical face masks in reducing bacterial contamination of a surface, produced by dispersal of organisms from the upper airway. Twenty-five volunteers were asked to speak at blood agar plates positioned in close proximity to the mouth, initially whilst not wearing a face mask and then wearing a surgical face mask over the mouth and nose. A fresh face mask almost completely abolished bacterial contamination of agar plates 30 cm from the mouth. After 15 min there was an increase in the level of contamination which was statistically insignificant.

Adult↗
PubMed1991

Effects of work on reproductive and productive performance of crossbred dairy cows in the Ethiopian highlands.

An investigation was made at the International Livestock Centre for Africa (ILCA) into the possibility of using cows in land cultivation as a means of reducing the dependency of smallholder farmers in the Ethiopian highlands on draught oxen power, a resource which is in short supply during the peak of the cultivation season and usually leads to late planting and poor harvest. A total of 32 crossbred cows (1/2 Boran-1/2 Friesian) were used in an experiment to determine whether cows could be used to cultivate an average smallholder farm of 2.5 ha and to assess the effects of work on reproductive and productive performance; 16 served as a control group and were milked but not worked while the other 16 were milked in addition to providing draught power for cultivation. Draught cows were provided with extra feed and consumed 7% and 21% more hay and concentrate respectively than non-draught cows during a two-lactation cycle. After the end of the second lactation there were no significant differences between draught and non-draught animals for milk production (1,713 +/- 57.4 compared with [vs] 1,857 +/- 48.1 kg), lactation length (291 +/- 20.4 vs 277 +/- 18.0 days), calf birth weight (29.6 +/- 1.0 vs 29.3 +/- 1.0 kg), number of days open (77 +/- 14.1 vs 83 +/- 12.9), calving interval (355 +/- 14.5 vs 358 +/- 13.2 days), gestation length (278 +/- 1.6 vs 274 +/- 1.4 days) and number of services per conception (1.21 vs 1.64). The number of hours worked by each pair of crossbred cows was sufficient to cultivate the average smallholder farm of 2.5ha.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Influence of partial suckling of crossbred dairy cows on milk offtake and calf growth in the Ethiopian highlands.

The effects of implementing a restricted suckling regime with crossbred dairy cows have been examined in the Ethiopian highlands. Calves were allowed to suckle their dams for two minutes before each milking until weaning and this system was compared with the common practice of rearing by bucket feeding. Restricted suckling significantly increased calf growth rate to weaning, from 0.31 to 0.53 kg/d (P less than 0.01). No differences in calf growth post-weaning occurred, so that the 20 kg difference in liveweight that had been achieved by the restricted suckled calves by the time of weaning persisted until the calves were nine months old, when observations ceased. Total milk offtake was not significantly affected by treatment, although that obtained from the partially-suckled animals over their whole lactation exceeded that from the other treatment by 15%. Partial suckling delayed return to oestrus post partum but this was offset to some degree by fewer services per conception, hence calving interval was not significantly increased. Voluntary feed consumption was similarly unaffected and it is concluded that restricted suckling offers tangible advantages for adoption by smallholders using crossbred cows in dairy production systems.

Animals↗
PubMed1990

Bone grafting for cranial reconstruction.

Precise reconstruction of defects of facial bones including the neurocranium is now possible with the use of CAD/CAM technology and biomaterials, such as OsteoMesh, combined with bone grafting.

Adult↗
PubMed1986

The volume of distribution of ceftazidime and albumin in normal, immature and infected bone.

The penetration of ceftazidime into bone was determined by measuring the volume of distribution of 14C-ceftazidime in infected and non-infected bone of adult mongrel dogs. The volume of distribution in non-infected cortical bone was 0.114 +/- 0.011 l/kg (mean +/- S.E.M.) and increased significantly in non-infected immature callus to 0.484 +/- 0.13 l/kg (P less than 0.05). In the presence of infection, the volume of distribution in non-infected cortical bone was 0.144 +/- 0.05 l/kg, and significantly higher in infected reactive cortical bone, 0.453 +/- 0.07 (P less than 0.05). We conclude that ceftazidime penetrates infected and non-infected bone and that this penetration is greater into immature bone.

Animals↗
PubMed1984

Extraction of ceftazidime in bone.

The extraction of ceftazidime has been measured in bone by means of the outflow dilution technique following injection into the perfused nutrient artery of the canine tibia. The instantaneous extraction was found to be 0.71 +/- 0.18 and the net extraction was 0.55 +/- 0.25 (mean +/- S.D. n = 5). The extraction of this antibiotic is relatively high and this experiment demonstrates the fact that antibiotics leave capillaries in bone and pass into the fluid spaces where they can act on pathogenic organisms.

Animals↗
PubMed1981

Treatment of coronal and metopic synostosis: 107 cases.

This paper presents a personal series of 107 children with synostosis, 53 unicoronal, 27 bicoronal, and 28 metopic cases (1 child had both metopic and bicoronal synostosis). In 16 patients, other vault sutures later closed partially, some requiring operation. All of the patients underwent surgical treatment without mortality or notable morbidity. Nineteen patients showed mild or moderate mental retardation; other defects included cleft palate, epicanthic folds, strabismus, and syndactyly. Three patients with unicoronal closure had a second operation about 5 years after the initial craniectomy, and 2 required a third procedure. Cranioplasty was done in 10 patients for persisting skull defects. The recent results have been satisfactory in most cases, probably because of more precise diagnosis and improved surgical techniques. It is concluded that craniofacial operations for synostosis should be as extensive as necessary, and if subsequent revision or cranioplasty is appropriate it should be done.

Child, Preschool↗
PubMed1979

Use of computerized tomography scanning in supratentorial arachnoid cysts. A report on 20 children and four adults.

Congenital supratentorial arachnoid cysts are large lesions that tend to cause severe distortion and compression of the brain, particularly in infants and children. Diagnosis of such cysts has often been delayed and uncertain in the past, but development of computerized tomography (CT) has greatly improved the ease and accuracy of their identification, helping to provide for earlier surgical treatment and better care of patients. The authors report 24 cases of congenital supratentorial arachnoid cysts, 18 of which were studied with CT scanning; this method proved very valuable in pre- and postoperative assessment in all cases, and far superior to other diagnostic methods.

Adult↗
PubMed1977

Anterior sacral meningocele. A presentation of three cases.

Anterior sacral meningoceles are congenital lesions that consist of a spinal fluid-filled sac in the pelvis communicating by a small neck with the spinal subarachnoid space through a defect in the sacrum. The three patients with this disorder presented here had characteristic symptoms snd physical findings: chronic constipation, a pelvic mass, and almost unmistakable roentgenographic changes, but diagnosis was delayed from 11 months to 21 years in all three. After prolonged and complicated treatment, the primary lesions have been surgically eradicated and function is generally satisfactory.

Child, Preschool↗
PubMed1975

Occult spinal dysraphism: a series of 73 cases.

The subject of occult spinal dysraphism or myelodysplasia is reviewed from standpoints of embryology, clinical manifestations, and treatment, and the management of 73 cases summarized. In general, these concealed lesions arise from developmental variants in the most distal part of the neural tube, a situation which may cause distortion or partial absence of neural tissues and also lead to damage from compression or traction. Lipomyelomeningocele and congenital dermal sinus are two exampled of the many types of such lesions, but some are more complicated and border-line myelomeningocele-like forms occur. Incontinence, deformity or weakness of the feet, impaired gait, and other difficulties may appear late and increase with growth. Surgical treatment is advised to reduce chances of delayed or progressive loss of function.

Adolescent↗