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Biomedical subjects

T Hollingworth

Publications and source records attributed to T Hollingworth.

13 recordsLinked to original sources

Type-specific human papillomavirus DNA in abnormal smears as a predictor of high-grade cervical intraepithelial neoplasia.

Human papillomavirus (HPV) typing and quantitation by polymerase chain reaction was performed on exfoliated cells from 133 women referred for colposcopy because of an abnormal smear. High levels of HPV 16 correctly predicted cervical intraepithelial neoplasia (CIN) grade II-III in 93% of its occurrences, but only 59% of cases of CIN III were associated with high levels of this type. Eighty-four per cent of CIN III lesions contained high levels of at least one of HPV types 16, 18, 31, 33 and 35, but the other types were less specific for CIN III than HPV 16. Overall HPV testing compared favourably with cytology for predicting high-grade CIN lesions, but it would appear that some combination of the two modalities will produce better performance than either alone. In particular, HPV testing appears to be helpful in determining which women with mildly abnormal smears have high-grade underlying lesions in need of immediate referral for colposcopy.

Base Sequence↗

Elevated serum alpha fetoprotein and normal liquor alpha fetoprotein values in association with an abdominal pregnancy.

A case report is described in which abdominal pregnancy was misdiagnosed by ultrasound scanning as a pregnancy within a horn of a bicornuate uterus. Two serum alpha fetoprotein (SAFP) results were greatly elevated and an amniocentesis was performed, the liquor alpha fetoprotein (LAFP) and karyotype were normal. Elective Caesarean section was performed at 38 weeks for a persistent transverse lie and an abdominal pregnancy was found. The outcome was excellent for both the mother and child. This is the first reported case of amniocentesis and measurement of LAFP in an abdominal pregnancy and confirms abdominal pregnancy as a rare cause of an elevated SAFP.

Adult↗

Human papillomavirus type 16 in cervical smears as predictor of high-grade cervical intraepithelial neoplasia [corrected].

The management of women with mild to moderately dyskaryotic cervical smears would benefit from a non-invasive test that predicts which women have high-grade cervical intraepithelial neoplasia. Detection of human papillomavirus type 16 (HPV16) DNA in cervical smears may be such a test. With the polymerase chain reaction (PCR), we estimated the amount of HPV16 DNA in cervical smears from 85 women referred for colposcopy because of abnormal cytology. An intermediate or high amount of HPV16 DNA predicted the presence of high-grade cervical intraepithelial neoplasia in a subsequent biopsy in almost 90% of patients irrespective of the cytological grade of the referral smear. This technique may allow early identification of those women with low-grade cytological abnormalities who have high-grade underlying cervical disease.

DNA, Viral↗

The natural history of early cervical neoplasia and cervical human papillomavirus infection.

This article deals with the natural history of cervical human papillomavirus infection and precancer. It traces the development of the transformation zone and maturation of the normal squamous epithelium. Potential aetiological agents and a possible cofactor are briefly discussed. The natural history of premalignant disease and its relationship to invasive disease is also covered.

Cell Transformation, Viral↗

Foamy myocardial transformation of infancy: an inherited disease.

Five cases of foamy myocardial transformation of infancy, a condition which predominantly affects female children under 2 years of age and which causes cardiac arrhythmia or sudden death, are reported. Of these five cases, four occurred in two sets of siblings, suggesting a possible hereditary basis for the disease. As far as we know, no other familial cases have been reported. The other case was of focal disease of the myocardium, as opposed to the diffuse myocardial changes seen in the four familial cases.

Cardiomyopathies↗

Network analysis of dendritic fields of pyramidal cells in neocortex and Purkinje cells in the cerebellum of the rat.

The connectivity within the dendritic array of Purkinje cells in the cerebellum and pyramidal cells of the neocortex of the rat, stained by the Golgi-Cox method, has been quantified by the method of network analysis. Connectivity was characterized either by applying the system of Strahler ordering, which assigns a relative order of magnitude to each branch of the arborescence or by the identification of unique topological branching patterns within the tree. The former method has been used to define the entire dendritic array of the Purkinje cell and the apical system of neocortical pyramids. It has been shown that the relation between the numbers of branches of successive Strahler order in Purkinje cells form an inverse geometric series in which the highest order is unity and the ratio between successive orders approximates to 3. On the other hand, the apical dendrites of neocortical pyramids exhibit two bifurcation ratios, i.e. a ratio of 3 between low orders and a ratio of 4 between higher orders. A computer simulation technique was used to generate networks of a size comparable with the Purkinje cell networks and grown according to two hypotheses namely, a 'terminal growth model' in which additional segments were added randomly to the terminal branches only and a 'segmental growth model' in which additional segments were added randomly to any branch within the array including terminal branches. Subsequent ordering of the simulated trees revealed that the relation between the numbers of successive orders for networks generated according to the 'segmental model' tended towards an inverse geometric series with a ratio of 4 and that generated according to the 'terminal model' tended towards a ratio of 3. This result showed that the dendritic tree of Purkinje cells grow in a manner indistinguishable from a system adding branches to random terminal segments and that neocortical apical dendrites add their collateral branches to random segments of the apical shaft but that the collateral branches themselves grow by random terminal branching. The possibility that such conclusions may be influenced by loss of branches incurred by either a failure of impregnation, by sectioning, or by environmental influences was investigated by means of a computer technique...

Animals↗

Application of network analysis to the study of the branching patterns of dendritic fields.

The technique of network analysis has been used to define the connectivity and growth of networks generated by monochotomous, dichotomous, and trichotomous branching. The number of distinct topologic branching patterns exhibited by networks with a given number of pendant arcs is defined mathematically; when all types are represented, a complete pendant arc series is formed. The frequency of occurrence of topologic types in these series is unique for a given hypothesis of growth. The growth of the small dendritic arrays such as the basal dendritic fields of neocortical pyramids may be studied by comparing the actual frequency of topologic types with those computed according to given hypotheses. For larger dendritic networks such as those of Purkinje cells in the cerebellum it is only practicable to use the topologic types formed by the peripheral parts of the tree as a basis for comparison. Individual dendritic segments can be ordered sequentially to define their hierarchical arrangement; the frequency of orders in a given network always forms an inverse geometric series. The ratio between orders is called the "bifurcation ratio," and the relationship in a given large series between adjacent orders becomes stabilized to a fixed or "established" bifurcation ratio at the periphery of the tree only. This "established ratio" characterizes the pattern of growth of the network. In the proximal part of the tree the ratio between adjacent orders is unstable and accounts for the variability of the overall bifurcation ratio exhibited by different networks with the same fundamental growth pattern and for the deviation of the overall from the established bifurcation ratio. For a given size of network the overall bifurcation ratio may be similar regardless of the mode of growth. It is concluded that the precise definition of branching structures afforded by network analysis makes this technique well suited for the study of the connectivity, growth, and morphology of dendritic trees.

Computers↗