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Biomedical subjects

C M James

Publications and source records attributed to C M James.

31 records · Page 2Linked to original sources
PubMed1994

Sequence analysis of a 3.5 Kb EcoRI fragment from the left arm of Saccharomyces cerevisiae chromosome XI reveals the location of the MBR1 gene and a sequence related to a GTPase-activating protein.

We present the DNA sequence analysis of a region covering a 3.5 kb EcoRI fragment from the left arm of chromosome XI from Saccharomyces cerevisiae. This region contains five open reading frames (ORFs) which code for proteins of greater than 100 amino acids. ORF YKL425 codes for the previously sequenced Mbr1 (Valens et al., 1991; Daignan-Fornier et al., 1993) which participates in mitochondrial biogenesis. YKL424 has identity with a GTPase-activating protein of higher eukaryotes. The three remaining ORFs have no identity to known proteins within the databases screened and are not assigned ORF numbers as they are completely contained with ORFs YKL424 and YKL425.

Amino Acid Sequence↗
PubMed1994

Late-onset Huntington's disease: a clinical and molecular study.

Using the Huntington's disease register for South Wales, a total of 86 affected individuals were identified living in the counties of Mid Glamorgan, South Glamorgan and Gwent, giving a point prevalence rate for Huntington's Disease in South East Wales of 6.2/100,000. Only four (4.7%) of these individuals developed their symptoms after the age of 60 years. A subsequent retrospective search of the register identified a total of 33 individuals with clinical evidence of Huntington's disease and whose age of onset of symptoms occurred between the ages of 60 and 77 years. In this group the median time for disease duration from the onset of symptoms was 13 years (range 0.5-25 years), with survival up to age 86 years recorded. Initial symptoms of Huntington's disease included disturbance of gait in 32 individuals; 31 had involuntary movements, and 20 had abnormality of speech. Major psychiatric symptoms were present in only six cases; but approximately a third (ten cases) had symptoms related to impaired cognitive function. Molecular analysis was possible on ten individuals in the series. The expanded CAG repeat sequence in the Huntington's disease gene was found in all cases, with a narrow range of 36-38 repeats, representing the smallest repeats seen in our Huntington's disease group. Our study suggests that Huntington's disease in elderly people causes predominantly motor disturbance at onset with relatively mild disability and a favourable outlook for both independent living and for life expectancy. However, the potential for under-diagnosis in this age group may have considerable genetic consequences, with transmission of the disorder to numerous descendants by the time its hereditary nature is recognized.

Aged↗
PubMed1994

Motor neurone disease--a study of prevalence and disability.

We conducted a point prevalence study of motor neurone disease in the counties of South Glamorgan, Mid Glamorgan and Gwent, whose combined population is estimated at 1,394,400. A total of 56 patients were identified, giving a point prevalence for motor neurone disease in this area of 4.02/100,000 on 22/06/92. These cases were reclassified according to the World Federation of Neurology criteria for amyotrophic lateral sclerosis following a further clinical assessment, when disability was also evaluated (in 49 cases). Seven patients were reclassified on review of their medical records alone. Overall, 38 were classified as either definite or probable cases, which gave a point prevalence of 2.73/100,000. Of these patients, 94% (46/49) were living at home, 43% (21/49) scored 15 or less on the Barthel index, 65% (32/49) had some degree of mobility impairment, and 20% (10/49) were wheelchair-dependent. Swallowing speed was reduced (< 10 ml/s) in 67% (33/49), with three requiring feeding through a percutaneous gastrostomy tube. Vital capacity was < 70% of predicted value for age, sex and height in 67% (29/43). One patient was receiving domiciliary ventilation. These results give a quantitative indication of the dependency in a population of patients with motor neurone disease.

Aged↗
PubMed1993

Cloning and sequence analysis of the coat protein gene of barley mild mosaic virus.

The sequence of the 3' 1462nts of RNA-1 of a UK isolate of the fungal-transmitted virus barley mild mosaic (BaMMV) has been determined. An open reading frame encoding the coat protein gene was identified within this region using amino acid sequence information obtained by cyanogen bromide cleavage of virus particles. The amino acid sequence of the full-length coat protein was deduced from the nucleotide sequence. Amino acid sequence comparisons revealed highest homology to the coat protein of barley yellow mosaic virus. In addition, a significant, but limited, number of the amino acid residues that are conserved between aphid-transmitted potyviruses were also conserved between BaMMV and potyviruses.

Amino Acid Sequence↗
PubMed1992

Expression of a single lignin peroxidase-encoding gene in Phanerochaete chrysosporium strain ME446.

A previously described linked set of lignin peroxidase-encoding genes (Lpo) from Phanerochaete chrysosporium (P.c.) ME446 is not expressed under standard growth conditions for ligninolytic activity. However, a single unlinked Lpo gene, not previously described in P.c. strain ME446, is expressed. The transcription start points of this gene are mapped and the gene is assigned to a genetic linkage group by the use of restriction-site polymorphism segregation analysis. No transcripts from Lpo-related genes, including that normally expressed in ME446, could be detected within RNA extracted from three nonligninolytic mutant strains, but a hyper-ligninolytic strain showed an increased level of Lpo expression. This increase is due to expression of additional Lpo genes, rather than to an increased level of transcription from the normally expressed sequence.

Base Sequence↗
PubMed1991

Duplex sonography in splenomegaly.

The aetiology of splenomegaly is seldom clear from either clinical or imaging assessment of the spleen. In the majority of cases sonographic assessment of the spleen produces a homogeneous enlargement of variable echodensity, but with very poor correlation with pathology. A study has been undertaken to assess the Doppler characteristics of the splenic artery in splenomegaly, excluding cases of portal hypertension in an attempt to provide further diagnostic information. Duplex assessment of 18 normal subjects and 10 patients with splenomegaly due to five different causes was undertaken. Analysis of waveform, peak frequency and pulsatility index were compared and failed to demonstrate any significant change. In the normal subject there is a broad systolic spectrum related to the tortuosity of the splenic artery, with persistence of forward flow throughout diastole, a reflection of the low peripheral resistance of the spleen. In splenomegaly the broad systolic spectrum is unchanged, since vessel tortuosity persists. Pathological and physiological assessment of the spleen in splenomegaly shows that a low resistance circulation persists, explaining maintenance of the diastolic flow pattern in splenomegaly. Increased blood flow to the spleen in splenomegaly occurs either as a result of an increase in vessel diameter or an increase in flow velocity, or a variable combination of the two which does not seem to be governed by specific pathology. An increase in peak frequency in some cases reflected some increase in flow velocity but provided no useful correlation. Analysis of the pulsatility index supported the above findings without adding further information.

Adolescent↗
PubMed1990

Sickle cell trait and military service.

In the community great efforts have been made to educate those with sickle cell trait that their condition is not a handicap and that they are fit to lead a normal life. It would be seen as a retrograde step for the Armed Forces to imply that they are in some way unfit for normal duties. The evidence presented demonstrates that with the exception of a small excess risk of sudden unexplained death during training there is no objection to recruiting those with sickle cell trait into the Royal Navy. At present those with sickle cell disorders are barred from service in the Royal Marine Commandos and from diving, submarine and aircrew service. On the basis of the evidence presented in this review a case can be made for allowing those with sickle cell trait to enter as aircrew in helicopters but not as pilots. In view of the requirements for military divers to operate in cold water under stressful conditions the exclusion of those with sickle cell trait is entirely justified. The overriding requirement must be the safety of both the affected individual and of others and the current regulations reflect this. Screening of all recruits and officer entrants in appropriate racial groups is not performed at present but would allow counselling and advice to be given to those affected by sickle cell trait at an early stage of their careers and the reasons for their exclusion from certain branches fully explained either by establishment Medical Officers or by the haematologist.(ABSTRACT TRUNCATED AT 250 WORDS)

Aerospace Medicine↗
PubMed1989

Sickle cell trait.

Explore the source record for details and available documents.

Anemia, Sickle Cell↗
PubMed1988

Plastid-localised seed acyl-carrier protein of Brassica napus is encoded by a distinct, nuclear multigene family.

Acyl-carrier protein (ACP) is a key component involved in the regulation of fatty acid biosynthesis in plants. cDNA clones encoding ACP from Brassica napus (oil seed rape) embryos have been isolated using oligonucleotide probes derived from heterologous ACPs. Analysis of the DNA sequence data, in conjunction with N-terminal amino acid sequence data, revealed ACP to be synthesized from nuclear DNA as a precursor containing a 51-amino-acid N-terminal extension. Immunocytochemical studies showed ACP to be localised solely within the plastids of B. napus seed tissue and it would therefore appear that the N-terminal extension functions as a transit peptide to direct ACP into these organelles. Analysis of several cDNA clones revealed sequence heterogeneity and thus evidence for an ACP multigene family. From ten cDNA clones, six unique genes, encoding five different mature ACP polypeptides, were identified. Northern blot hybridisation studies provide evidence that the seed and leaf forms of rape ACP are encoded by structurally distinct gene sets.

Acyl Carrier Protein↗
PubMed1987

Molecular cloning and sequence analysis of complementary DNA encoding rat mammary gland medium-chain S-acyl fatty acid synthetase thio ester hydrolase.

Poly(A)+ RNA from pregnant rat mammary glands was size-fractionated by sucrose gradient centrifugation, and fractions enriched in medium-chain S-acyl fatty acid synthetase thio ester hydrolase (MCH) were identified by in vitro translation and immunoprecipitation. A cDNA library was constructed, in pBR322, from enriched poly(A)+ RNA and screened with two oligonucleotide probes deduced from rat MCH amino acid sequence data. Cross-hybridizing clones were isolated and found to contain cDNA inserts ranging from approximately 1100 to 1550 base pairs (bp). A 1550-bp cDNA insert, from clone 43H09, was confirmed to encode MCH by hybrid-select translation/immunoprecipitation studies and by comparison of the amino acid sequence deduced from the DNA sequence of the clone to the amino acid sequence of the MCH peptides. Northern blot analysis revealed the size of the MCH mRNA to be 1500 nucleotides, and it is therefore concluded that the 1550-bp insert (including G X C tails) of clone 43H09 represents a full- or near-full-length copy of the MCH gene. The rat MCH sequence is the first reported sequence of a thioesterase from a mammalian source, but comparison of the deduced amino acid sequences of MCH and the recently published mallard duck medium-chain S-acyl fatty acid synthetase thioesterase reveals significant homology. In particular, a seven amino acid sequence containing the proposed active serine of the duck thioesterase is found to be perfectly conserved in rat MCH.

Amino Acid Sequence↗
PubMed1981

Simulation of a memory deficit on the Continuous Recognition Memory Test.

Simulation of a memory deficit on the Continuous Recognition Memory Test was studied, with 20 male and 20 female normal undergraduates assigned to each of two conditions. Simulation with prior test experience was studied by comparing performance following standard and then simulation instructions. A significant increase in false alarms was associated with a significant decrease in correct responses, d', c, and a slight decrease in hits. For studying simulation without prior test experience, the test was administered once with instructions to simulate. Performance was similar to simulation with test experience. Comparisons with the performance of closed head-injured patients were made.

Adult↗