Biomedical subjects
Publications and source records attributed to P Heath.
This paper describes a case of spinal tuberculosis diagnosed at 29 weeks' gestation in a primigravid Indian woman. The report illustrates the primary problems in suspecting disease, recognizing the diverse clinical presentations and initiating investigations to confirm the diagnosis. In most cases, M. tuberculosis, once recognized and appropriately treated, should result in an excellent prognosis.
The slow progression of diabetic retinopathy makes it difficult to assess the effects of intervention therapy. There is thus a need for surrogate markers of visual change in diabetes. Colour vision tests and electroretinography (ERG) may be useful in this regard; yet little is known of their relative performance in the assessment of visual dysfunction in diabetes. The aim of the present study was to compare colour discrimination (100 hue test) and ERG indices (oscillatory potentials (OP) and pattern ERG (PERG)) in the evaluation of aretinopathic IDDM patients. Colour discrimination was abnormal in 10 aretinopathic IDDM patients when compared with nine age matched controls; mean square root 100 hue error scores were 10.38 (SD 2.89) versus 4.77 (1.87) respectively, p < 0.01. OP implicit times of the ERG were also abnormal; for example, for right eye, mean OP1 implicit time for diabetics versus OP1 implicit time for controls was 20.1 (2.0) versus 18.6 (1.4) ms, p = 0.03. Comparison of the two techniques suggested that the 100 hue test was more sensitive and more specific than ERG OP implicit times in the detection of diabetic visual dysfunction in these patients.
The human aldose reductase (AR) gene has been mapped to chromosome 7 using the polymerase chain reaction to specifically amplify the human AR sequence in hamster/human hybrid DNA and also in mouse/human monochromosome hybrids. The assignment to chromosome 7 was confirmed by in situ hybridisation to human metaphase chromosomes using a novel, rapid hybridisation, method giving a regional localisation at 7q35.
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Recently there has been an expansion of day surgery in Britain. However, it is difficult to prove that surgical treatment on a day case basis actually saves money. This paper discusses the development of a new costing strategy which suggests that costs could be reduced by a planned programme of day surgery. These results have obvious significance for the National Health Service.
The efficiency of the National Health Service (NHS) is currently under scrutiny and the problems faced by the surgical services include a shortage of financial resources, fewer beds, poor nursing recruitment and rising waiting lists. During 1984-1988 a purpose built, separate 12-bedded day surgery unit at Addenbrooke's Hospital, Cambridge operated upon 13,000 patients, with a readmission rate of less than 1%. Senior medical staff are involved and the overall surgical waiting list has been reduced by 40.9%. Nurse recruitment has been excellent, and the community medical and nursing services have not been overburdened. The results detailed in this paper suggest that day surgery deserves special consideration as one acceptable solution to some of the current NHS problems.
The perinatal mortality of 613 children who were born to women with diabetes mellitus who attended the Diabetic Clinic of The Royal Women's Hospital between 1970 and 1985 was 4.5%. In 399 children who were born to mothers with pre-existing diabetes (95% of whom were insulin-dependent) the over-all perinatal mortality was 7.5%. In successive five-year periods, perinatal mortality in this group declined from 12.2% to 3.9% (1981-1985). In 214 children who were born to mothers with gestational diabetes, the perinatal loss was 1.4%. Between 1970 and 1985, the fetal loss that was attributed to poor control of diabetes declined; however, the prevalence of congenital abnormalities remained unchanged and these were the major cause of fetal loss in 1981-1985. Other high-risk categories that were identified included obstetric complications, particularly that of pre-eclampsia. Neonatal complications had little effect on the eventual outcome, but respiratory distress, macrosomia, hypoglycaemia, jaundice, polycythaemia, hypocalcaemia and hypomagnesaemia were documented frequently and required specialized assessment. The causes of the improvement in the outcome of pregnancy in women with pre-existing diabetes appear to be multifactorial and due to team management in a specialized unit. A reduction in the increased prevalence of major congenital abnormalities is the major challenge for the future.
A consensus sequence for the human long interspersed repeated DNA element, L1Hs (LINE or KpnI sequence), is presented. The sequence contains two open reading frames (ORFs) which are homologous to ORFs in corresponding regions of L1 elements in other species. The L1Hs ORFs are separated by a small evolutionarily nonconserved region. The 5' end of the consensus contains frequent terminators in all three reading frames and has a relatively high GC content with numerous stretches of weak homology with AluI repeats. The 5' ORF extends for a minimum of 723 bp (241 codons). The 3' ORF is 3843 bp (1281 codons) and predicts a protein of 149 kD which has regions of weak homology to the polymerase domain of various reverse transcriptases. The 3' end of the consensus has a 208-bp nonconserved region followed by an adenine-rich end. The organization of the L1Hs consensus sequence resembles the structure of eukaryotic mRNAs except for the noncoding region between ORFs. However, due to base substitutions or truncation most elements appear incapable of producing mRNA that can be translated. Our observation that individual elements cluster into subfamilies on the basis of the presence or absence of blocks of sequence, or by the linkage of alternative bases at multiple positions, suggests that most L1 sequences were derived from a small number of structural genes. An estimate of the mammalian L1 substitution rate was derived and used to predict the age of individual human elements. From this it follows that the majority of human L1 sequences have been generated within the last 30 million years. The human elements studied here differ from each other, yet overall the L1Hs sequences demonstrate a pattern of species-specificity when compared to the L1 families of other mammals. Possible mechanisms that may account for the origin and evolution of the L1 family are discussed. These include pseudogene formation (retroposition), transposition, gene conversion, and RNA recombination.
A case is reported of a patient who experienced numerous episodes of transient global amnesia (TGA) during which anterograde amnesia was less prominent than usual, and who developed a permanent selective retrograde amnesia. On formal testing, he performed well on traditional verbal memory tests, but showed marked retrograde amnesia for verbal material, including items on a famous voices recognition test. He was administered a paired-associate learning test where the names of famous personalities for which he was amnesic were associated with incongruous activities (e.g. John Newcombe-singing). Our patient performed better on this task than a group of five matched control subjects. Our observations indicate that in the organization of human memory retrograde amnesia may be fractionated from anterograde amnesia and that in certain situations specific types of amnesia can produce a facilitation effect compared to the performance of control subjects.
Intrauterine growth retardation is a condition of chronic fetal compromise. The most accurate method of fetal assessment in this condition is by serial cardiotocography. In pregnancy associated with intrauterine growth retardation, abnormal cardiotocography with spontaneous decelerations may be an indicator of imminent fetal death in utero. Delivery should be effected immediately if the fetus is at a gestation where viability is probable.
Two fetal globin genes (G gamma and A gamma) from one chromosome of a lowland gorilla (Gorilla gorilla gorilla) have been sequenced and compared to three human loci (a G gamma-gene and two A gamma-alleles). A comparison of regions of local homology among these five sequences indicates that long after the duplication that produced the two nonallelic gamma-globin loci of catarrhine primates, about 35 million years (Myr) ago, at least one gene conversion event occurred between these loci. This conversion occurred not long before the ancestral divergence (about 6 Myr ago) of Homo and Gorilla. After this ancestral divergence, a minimum of three more gene conversion events occurred in the human lineage. Each human A gamma-allele shares specific sequence features with the gorilla A gamma-gene; one such distinctive allelic feature involves the simple repeated sequence in IVS 2. This suggests that early in the human lineage the A gamma-genes may have undergone a crossing-over event mediated by this simple repeated sequence. The DNA sequences from coding regions of both G gamma- and A gamma-loci, a comparison of 292 codons in the corresponding gorilla and human genes, show an unusually low evolutionary rate, with only two nonsilent differences and, surprisingly, not even one silent substitution. The two nonsynonymous substitutions observed predict a glycine at codon 73 and an arginine at codon 104 in the gorilla A gamma-sequence rather than aspartic acid and lysine, respectively, in human A gamma. Because only arginine has been found at position 104 in gamma-chains of Old World monkeys, it may represent the ancestral residue lost in gorilla and human G gamma-chains and in the human A gamma-chain. Possibly the arginine codon (AGG) was replaced by the lysine codon (AAG) in the G gamma-gene of a common ancestor of Homo and Gorilla and then was transferred to the A gamma-gene by subsequent conversions in the human lineage. DNA sequence conversions, similar to that attributed to the fetal gamma-globin genes, appear to be relatively frequent phenomena and, if widespread throughout the genome, may have profound evolutionary consequences.
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Pregnancy in 207 diabetic women managed at a diabetic antenatal unit over a six-year period (1970 to 1976) resulted in a perinatal mortality of 16 (7-8%). One hundred and fifty-nine women (70%) were receiving insulin before pregnancy and 20% had evidence of diabetic microangiopathy. Still birth was twice as frequent as neonatal death, and severe respiratory distress syndrome was uncommon, resulting in only one death. Bad control of diabetes was associated with a poor prognosis. This was contributed to be lack of cooperation, anxiety and poor knowledge of diabetes. The accurate assessment of gestation and maturity, the monitoring of fetal-placental function, careful blood glucose level control, and an understanding of neonatal physiology have contributed to a reduction in fetal mortality. Close cooperation between an obstetrician, physician and neonatal pediatrician experienced in the problems encountered in the management of pregnant diabetic women is essential if the best results are to be obtained.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.