Atypical Growth Pattern Research Articles

Can histopathologists reliably diagnose molar pregnancy?

To assess the degree of difficulty in diagnosing partial mole by analysing intraobserver and interobserver agreement among a group of pathologists for these diagnoses. Fifty mixed cases of partial mole, complete mole, and non-molar pregnancy were submitted to seven histopathologists, two of whom are expert gynaecological pathologists; the other five were district general hospital consultants, one of whom works in Australia. These participants gave each slide a firm diagnosis of either partial mole, complete mole, or non-molar pregnancy. Some 12 months later, the slides were recorded and again submitted for a second diagnostic round to assess intraobserver as well as interobserver agreement. Standard histological criteria for each diagnostic category were circulated with the slides. kappa statistics showed that complete mole could be reliably distinguished from non-molar pregnancy, but neither non-molar pregnancy nor complete mole could be easily differentiated from partial mole. In only 35 out of 50 cases was there agreement between five or more of the seven participants. Agreement between the expert gynaecological pathologists was no better than for others in the group. Interestingly, the intraobserver agreement for each pathologist was good to excellent. These results imply that the reported histological criteria are either not being applied consistently or that they are lacking in practical use. An atypical growth pattern of trophoblast, rather than the polar accentuation seen in normal first trimester pregnancies, seems to be the important diagnostic histological feature for partial mole. Ploidy studies might also help with problem cases.

Structure and growth of a high-level population ofCerastoderma edule(Lamellibranchiata)

The allometric relationships between shell length and shell breadth, shell height, shell weight, wet tissue weight and dry tissue weight are described for a population ofCerastoderma eduleliving at a high tidal level in the Dovey Estuary, West Wales. Seasonal fluctuations in standard animal values for shell weight and dry weight are interpreted in terms of the cycles of reproduction and food availability; the dangers associated with the use of wet weight in growth studies are demonstrated. The population structure is described using a combination of length-frequency and growth ring analyses and comprised nine year-classes with overlapping size ranges. The growth of the population was very slow and the relative growth rate was almost constant; associated with this slow, atypical growth pattern was considerable longevity and a small maximum size. The reasons for these characteristics are discussed.

Occurrence of focal three-dimensional proliferation in cultured human cells after prolonged infection with herpes simplex virus.

The occurrence of focal three-dimensional proliferation was observed in human conjunctiva cells in culture after prolonged infection with herpes simplex virus at 30 degrees C. and in KB cells infected with herpes virus at 37 degrees C. for several months in the presence of pooled human serum. This atypical growth pattern consisted of many discrete piles of cells 15 to 20 cells thick scattered over a monolayer of cells. Three-dimensional growth appeared only in the presence of 10 to 20 per cent of selected human sera. When horse serum was substituted for human serum growth was in an ordinary monolayer. The abnormal growth pattern of this cell line (C-4 line) has remained stable through continuous culture for over 2 years and was observed consistently in each of 25 clones isolated from the parent culture. Repeated tests for the presence of persisting infectious virus and for herpes virus antigen in the cells were negative. Comparison of the C-4 cell line with control conjunctiva cells revealed no significant difference in multiplication rate or in range of viral susceptibility, but the C-4 line was found to be more sensitive to ultraviolet irradiation.