Biomedical subjects
Publications and source records attributed to C Griffiths.
Intravenous, oral, and topical formulations of acyclovir have been successful in treating genital herpes. We report on two patients who developed skin reactions while taking acyclovir, which resolved when treatment was stopped.
An education programme on AIDS has been established in West Glamorgan. It was designed to provide an information network amongst health authority staff which would reach as wide an audience as possible. The programme has been organised on a direct contact approach because of the limitations of other methods of disseminating information to large groups of people. The initial success of the programme has led to its extension among other interested groups in West Glamorgan such as the prison population, drug groups, and members of the gay community. The programme is to continue and be updated on a regular basis.
Twenty-two patients with nasal septal carcinoma have been treated at the University of Texas Medical Branch, Galveston, during the 18-year period from 1961 to 1979. Squamous cell carcinoma of the nasal septum was found in 18 patients (82%), with single instances of reticulum cell sarcoma, basal cell carcinoma, histiocytic lymphoma, and transitional cell carcinoma. One of the squamous cell carcinoma group had palpable cervical metastasis at diagnosis, with metastatic neck disease developing in eight patients from three to 25 months after treatment. Squamous cell carcinoma of the nasal septum is aggressive and often undertreated. Our experience suggests that patients with septal carcinoma of any size should be treated by wide surgical excision (via lateral rhinotomy) and irradiation to the primary site and neck. Control of the primary tumor was achieved in 17 of 18 patients, with neck control in ten patients. The five-year absolute survival rate for squamous cell carcinoma of the nasal septum was 66%.
Computer digitization of M-Mode echocardiograms has proved a valuable research tool in the study of left ventricular function. It can be applied in clinical practice if the reproducibility of the technique is known so that imprecision can be minimised. Five normal echocardiograms of average clinical quality were selected and four cycles from each echocardiogram were digitized on two occasions by four different digitizers using an 'Apple II' computer. The study design allowed the sources of imprecision to be identified by analysis of variance. Assessment of the clinically most useful digitized measurement, peak rate of change of diastolic left ventricular dimension (dD/dt), was imprecise with a large within-subject variance and a 95% confidence interval of +/- 6.5 cm s-1; too wide for clinical use. The replication component accounted for 90% of this variance, with cycle to cycle and between-digitizer variance components being much less important. This large replication component will be reduced simply by repeating digitization; for dD/dt repeating digitization four times would theoretically reduce the confidence interval to a useful value of +/- 3.6 cm s-1. The 95% confidence interval for a single digitised measurement of diastolic left ventricular minor dimension was +/- 0.32 cm, for diastolic posterior wall thickness +/- 0.23 cm, and for the isovolumic relaxation time (A2-MVO) +/- 27 ms. Replication was again the largest component of variance so that the biggest improvement in precision will come from simply repeating digitization. Digitization on a cheap microcomputer system can provide clinically useful information provided reproducibility and sources of imprecision are known with clinical, as opposed to research, echocardiograms and conditions.
The vestibular apparatus of the decerebrate rat was stimulated by tilting the head dorsally or ventrally, with or without an associated stimulation of neck afferents i.e. either the head alone, or the head and body together, was tilted. The effect of such conditions, upon short latency reflexes elicited in antagonistic jaw and hyoid muscles, was examined. Reflexes in the different jaw and hyoid muscles were affected differently when the head was tilted, whether or not neck movement was permitted. Variations in the pattern of response in different animals were explicable on the basis of the known variable recovery of neck reflexes opposing the influence of the vestibular afferents. Head position can therefore be an important but complex factor which may enhance or depress reflex activity differentially in the different masticatory muscles, at least in the experimental situation.
Mechanical stimulation of the oral cavity of the decerebrate rat induces rhythmic oral movements in some animals but not in others. Reasons for this difference were sought using electrical stimulation of the lip to elicit a variety of responses which were capable of accurate quantification. Neither the digastric reflex threshold, size of suprathreshold response nor the ability to generate rhythmic activity within the brainstem differed in the two groups. Depression of the digastric reflex by an electrical stimulus applied 30-150 ms previously was, however, significantly greater in those animals not showing rhythmic oral movements. It is suggested that the two groups differed in their ability to produce rhythmic oral movements because of differences in the level of stimulus related inhibition rather than any tonic effects on trigeminal neuronal activity.
Breakfasts of lentils or wholemeal bread of identical carbohydrate content were taken by seven healthy volunteers. The lentils produced a significant 71% (p less than 0.001) reduction in the blood glucose area and flattened the plasma insulin and gastric inhibitory polypeptide responses by comparison with the bread. In addition, the lentil breakfast was followed by a significantly flatter blood glucose response to the standard bread lunch which followed 4 h later (by 38%, p less than 0.01). The blood glucose pattern was mimicked by feeding the bread breakfast slowly over the 4 h before lunch. Giving a bread breakfast containing a quarter of the carbohydrate reduced the breakfast glucose profile but resulted in a significantly impaired blood glucose response to lunch (168% of control, p less than 0.01). These results, together with breath hydrogen studies, performed on a separate group of four volunteers, indicate that the flattened response to lentils is not due to carbohydrate malabsorption. Slow release or "lente" carbohydrate foods such as lentils may form a useful part of the diets of those with impaired carbohydrate tolerance.
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Rats decerebrated at different ages (4 days to greater than 100 days) were tested for a rhythmic reflex 'suckling' response and for a simple digastric reflex. The ease with which the 'suckling' response could be elicited decreased with increasing age; the time course of this change approximated to that of changing characteristics of the digastric reflex. The mean latency of the simple reflex response decreased non-linearly from 70 msec in the 4 day postpartum animal to 5 msec in the adult animal; the duration of the response also decreased from 25 msec to 10 msec but this change took place mainly between 8 and 15 days postpartum. The latency of the digastric response also shortened in animals decerebrated on day 4 and kept for 2 days. It was concluded that the observed changes in the digastric reflex occurred independently of encephalic structures.
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A double blind crossover trial was carried out to assess the effect of povidone iodine on plaque accumulation in vivo and to measure the total salivary aerobes and anaerobes throughout the study. When compared to the placebo preparation, povidone iodine was without effect on plaque accumulation in all the subjects and there was a progressive increase in plaque throughout the 10-day periods. A 30 to 40 % overall reduction in aerobes and anaerobes occurred with the active preparation which was significant. There appears to be no indication for the use of povidone iodine as an adjunct to oral hygiene or in the treatment of chronic gingivitis.
According to cell cycle synchrony principles, bleomycin was infused for 48 hours, followed by a dose of either methotrexate or hydroxyurea after a 24-hour rest, in 36 adult patients with disseminated carcinoma. In this preliminary study, a 59% response rate was noted among patients with epidermoid carcinoma of the head and neck. Four of four patients with transitional cell carcinoma of bladder and one patient with hypernephroma also responded. No responses were noted among five patients with epidermoid carcinoma of the lung. The length of response ranged from 1 to 8 months (median, 2 months). Seventy-seven percent of the responders had extensive prior radiotherapy. The first patient treated had fatal sepsis with leukopenia, which prompted a widening of the treatment interval. Subsequently, toxicity was mainly mild or absent, the moderate or severe toxicity was primarily neutropenia, which was reversible. The use of low-dose bleomycin infusion is safe and may play a role in cancer therapy in combination with other agents specific for certain tumors. The length of infusion should be determined by the cell cycle of the tumor, if its potential synchronizing capabilities are to be exploited.
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The finished sequence of human chromosome 20 comprises 59,187,298 base pairs (bp) and represents 99.4% of the euchromatic DNA. A single contig of 26 megabases (Mb) spans the entire short arm, and five contigs separated by gaps totalling 320 kb span the long arm of this metacentric chromosome. An additional 234,339 bp of sequence has been determined within the pericentromeric region of the long arm. We annotated 727 genes and 168 pseudogenes in the sequence. About 64% of these genes have a 5' and a 3' untranslated region and a complete open reading frame. Comparative analysis of the sequence of chromosome 20 to whole-genome shotgun-sequence data of two other vertebrates, the mouse Mus musculus and the puffer fish Tetraodon nigroviridis, provides an independent measure of the efficiency of gene annotation, and indicates that this analysis may account for more than 95% of all coding exons and almost all genes.