Estimating development rate and thermal requirements of Bactericera cockerelli (Hemiptera: Triozidae) reared on potato and tomato by using linear and nonlinear models.

The temperature-dependent development of tomato psyllid (also called potato psyllid), Bactericera cockerelli (Sulc), was studied in the laboratory at seven constant temperatures (8, 10, 15, 20, 23, 27, and 31°C), 50-60% RH, and a photoperiod of 16:8 (L:D) h on leaves of whole potato (Solanum tuberosum L.) and tomato (Solanum lycopersicum L.) plants. Developmental time in days for immature stages and total development (egg to adult) on both host species were inversely proportional to temperature between 8 and 27°C but increased at 31°C. One linear and two nonlinear models were fitted to the data. The lower developmental thresholds, calculated using the linear model for egg, total nymph, and total development (from oviposition to adult emergence) were 7.9, 4.2, and 7.1°C (reared on potato) and 7.2, 5.3, and 7.5°C (reared on tomato), respectively. The thermal constant (K) for total development was 358 (reared on potato), and 368 (reared on tomato) degree-days (DD). Two nonlinear models, Briere and Lactin, fit the data well as measured by goodness-of-fit criteria, the residual sum of square (RSS) and Akaike information criterion (AIC). Temperature threshold parameters for these nonlinear models (T(0), T(opt), and T(max)) were estimated for eggs, total nymphal stages, and total development time (egg to adult). The Briere model is highly recommended for the description of temperature-dependent development of tomato psyllid. Results from this study will provide basic information on the biology of tomato psyllid and have potential for the development of predictive models of the seasonal progress of this invasive pest.

An interspecific comparison of foraging range and nest density of four bumblebee (Bombus) species.

Bumblebees are major pollinators of crops and wildflowers in northern temperate regions. Knowledge of their ecology is vital for the design of effective management and conservation strategies but key aspects remain poorly understood. Here we employed microsatellite markers to estimate and compare foraging range and nest density among four UK species: Bombus terrestris, Bombus pascuorum, Bombus lapidarius, and Bombus pratorum. Workers were sampled along a 1.5-km linear transect across arable farmland. Eight or nine polymorphic microsatellite markers were then used to identify putative sisters. In accordance with previous studies, minimum estimated maximum foraging range was greatest for B. terrestris (758 m) and least for B. pascuorum (449 m). The estimate for B. lapidarius was similar to B. pascuorum (450 m), while that of B. pratorum was intermediate (674 m). Since the area of forage available to bees increases as the square of foraging range, these differences correspond to a threefold variation in the area used by bumblebee nests of different species. Possible explanations for these differences are discussed. Estimates for nest density at the times of sampling were 29, 68, 117, and 26/km2 for B. terrestris, B. pascuorum, B. lapidarius and B. pratorum, respectively. These data suggest that even among the most common British bumblebee species, significant differences in fundamental aspects of their ecology exist, a finding that should be reflected in management and conservation strategies.

Expression of Ki-67 and cytokeratin 20 in hyperplastic polyps of the colorectum.

AIMS: To study the expression of Ki-67 and cytokeratin 20 (CK20) in a group of hyperplastic polyps (including a group with "atypical" features) with the aim of determining whether upper crypt Ki-67 staining and lower crypt CK20 staining correlated with these atypical features, as assessed by light microscopy. METHODS: Fifty seven formalin fixed, paraffin wax embedded hyperplastic colorectal polyps from 53 patients were selected on histological grounds; these comprised 26 typical polyps and 31 with atypical features, which included nuclear hyperchromatism, basal crowding, and increased mitotic activity. These polyps were examined using a standard immunohistochemical method with antibodies against CK20 and Ki-67. Comparisons were made with normal mucosa, adenomatous polyps, and carcinomas. RESULTS: Of the 26 typical polyps, 17 showed the usual pattern of lower crypt Ki-67 and upper crypt CK20 staining; one with upper crypt Ki-67 staining but normal surface CK20 staining; seven with Ki-67 confined to the lower half of crypts but with scattered lower crypt CK20; and one with both upper crypt Ki-67 staining, together with scattered CK20 basal staining. Of the 31 polyps with atypical features, 11 showed the usual staining pattern of lower crypt Ki-67 staining and surface staining with CK20; two showed Ki-67 staining extending into the upper half of crypts, but with a normal surface staining with CK20; 14 showed Ki-67 confined to the lower half of crypts, but scattered lower crypt staining with CK20; and four showed upper crypt Ki-67 staining together with scattered CK20 lower crypt staining. CONCLUSIONS: The normal pattern of lower crypt Ki-67 and upper crypt CK20 was seen in 28 of the 57 hyperplastic polyps and, in general, this corresponded with standard light microscopic appearances. Twenty one of the 57 polyps showed lower crypt mosaic CK20 staining, which in general corresponded with basal abnormalities on light microscopy, although seven specimens had normal appearances. Two smaller subsets emerged, one showing upper crypt Ki-67 staining in the presence of normal CK20 expression (three cases) and another in which a combination of lower crypt CK20 and upper crypt Ki-67 expression was seen (five cases). This last pattern was similar to that of neoplastic polyps and raises the possibility that a subgroup of hyperplastic polyps exists that may be a variant with malignant potential. Further studies with markers of mismatch repair genes and K-ras mutations may help to clarify this issue.

p53 expression in carcinoma of the cervix.

AIM: To assess overexpression of the proposed tumour suppressor gene product p53 using the mouse monoclonal antibody DO-7 in the three main subtypes of carcinoma of the uterine cervix and to evaluate its value as a prognostic indicator. METHODS: Eighty two cases of FIGO Stage IB/IIA uterine cervical carcinoma were studied retrospectively. The tumours had been previously typed into adenocarcinomas, squamous carcinomas and adenosquamous carcinomas after the tissue had been fixed in formalin and embedded in paraffin wax. p53 protein expression was assessed using a standard immunohistochemical technique and the findings were correlated with tumour type, lymph node status and clinical outcome. RESULTS: In total, the p53 gene product was overexpressed in 17.1% (14/82) of all carcinomas and also in areas of cervical intraepithelial neoplasia grade III adjacent to invasive squamous carcinoma. Where present, the normal epithelium was uniformly negative. No association was found between p53 overexpression and tumour subtype, lymph node status or clinical outcome. CONCLUSIONS: It seems unlikely that p53 analysis will be of value in determining prognosis in carcinoma of the uterine cervix.

Gastric tuberculosis presenting with massive hematemesis in association with acute myeloid leukemia.

This case report presents a patient with gastric tuberculosis, in remission from acute myeloid leukemia, who suffered a massive hematemesis, ultimately proving to be fatal. The literature of gastric tuberculosis is reviewed with particular reference to its clinical presentation and diagnosis.

Neuroendocrine differentiation in cervical carcinoma.

AIMS: To examine neuroendocrine differentiation, as shown by chromogranin A (CGA) expression, in cervical carcinomas. METHODS: Sixty seven cervical carcinomas were studied and were classified as adenocarcinomas, adenosquamous carcinomas or squamous cell carcinomas based on the assessment of haematoxylin and eosin staining and stains for mucin. Where features of glandular differentiation were identified, sections were also stained for evidence of intestinal type mucin. CGA immunostaining was done and the results were graded on a three point scale: 0, + (1-5% of cells positive) and ++ (> 5% of cells positive). These findings were then analysed with respect to lymph node status, tumour differentiation and clinical outcome. RESULTS: There were 32 adenocarcinomas, 18 adenosquamous carcinomas and 17 squamous cell carcinomas. Positive staining was seen in 14 (20.9%) cases, of which four were strongly positive. All but one case were either adenocarcinomas or adenosquamous carcinomas. There was a trend for CGA positivity to be related to intestinal differentiation but this failed to reach statistical significance. No correlation could be demonstrated between CGA staining and lymph node status, tumour differentiation and clinical outcome. CONCLUSIONS: Neuroendocrine differentiation is common in cervical carcinomas where there is evidence of glandular differentiation. Whilst the numbers in this study are relatively small, the presence of neuroendocrine cells in otherwise typical carcinomas does not seem to have any association with clinical behaviour.

Clear cell adenosquamous carcinoma of the cervix. An aggressive tumor associated with human papillomavirus-18.

BACKGROUND: It is well recognized that adenocarcinomas and adenosquamous carcinomas of the cervix are frequently associated with human papillomavirus (HPV)-16 or -18. However, few studies have investigated associations between histologic variants of these tumors and specific types of HPV. METHODS: Eleven cases of cervical adenosquamous carcinoma with an unusual histologic appearance were characterized using histochemical and immunohistochemical stains. Sections were tested for the presence of HPV DNA using the polymerase chain reaction (PCR) and type specific primers for HPV-16 and -18. Clinical outcome was determined from a chart review. RESULTS: All tumors were histologically characterized by the presence of sheets of cohesive cells with prominent cell borders and a vacuolated or clear cytoplasm containing large amounts of glycogen. All tumors had focal gland formation and stained positive with mucicarmine stain. Using PCR, HPV-18 DNA was identified in all cases. The youngest patient was 24 years old and the oldest 74 years (mean, 43 years). Eight (73%) of the 11 patients have developed recurrent disease with a mean follow-up until recurrence of 9.5 months (range, 3-22 months). Seven (64%) of the 11 patients have died of their cervical tumors. Of the five patients with Stage IB disease, three (60%) have died of their cervical tumors. CONCLUSIONS: A subset of invasive cervical adenosquamous carcinoma associated with HPV-18 that has a distinctive histologic appearance and an aggressive clinical course is described. The term "clear cell adenosquamous carcinoma" is proposed for this unique variant of invasive cervical carcinoma.

c-erbB-3 proto-oncogene expression in uterine cervical carcinoma.

Over-expression of epidermal growth factor receptor (EGFR) and c-erbB-2, in uterine cervical carcinomas, is associated with a worsened prognosis. A third member of this proto-oncogene family, c-erbB-3, has now been identified and its over-expression has been described in a variety of carcinomas. In this immunohistochemical study we have shown that c-erbB-3 is widely expressed in cervical carcinomas, but we have found no association between its over-expression and lymph node status or clinical outcome. In a similar study examining the expression of EGFR and c-erbB-2 it was possible to demonstrate an association between over-expression and a worse prognosis. We conclude, therefore, that it is unlikely that demonstration of c-erbB-3 over-expression will be of any value as a prognostic indicator in carcinoma of the uterine cervix.

Amyloid tumour of the colon.

A case of amyloid tumour of the colon and the first in association with a carcinoma is reported. A previously healthy 65 year old man presented with non-specific symptoms of lower abdominal pain and flatulence without rectal bleeding. A clinical diagnosis of diverticular disease was made and colonoscopy performed. Two lesions (one at 15 cm and the other at 30 cm from the anal margin) were found on endoscopy and removed. On histology, the lesion at 15 cm was a moderately differentiated adenocarcinoma and that at 30 cm contained amyloid. Further tests (standard tinctorial methods and immunohistochemistry) revealed the 30 cm lesion to be an amyloid tumour of the colon of AL (lambda) type. When biopsy of an atypical, large, solitary colorectal lesion reveals amyloid deposition, the possibility of an amyloid tumour should be considered and the lesion resected.

Proliferating cell nuclear antigen (PCNA) immunoreactivity in ovarian serous and mucinous neoplasms: diagnostic and prognostic value.

Sixty-two serous and mucinous ovarian tumors, an admixture of benign, borderline and malignant neoplasms, were immunostained for proliferating cell nuclear antigen (PCNA), with the monoclonal antibody PC10. The PC10 index, the proportion of cells showing nuclear positive staining, was calculated in each case. All the tumors showed positive immunoreactivity for PCNA. There was no overlap of PC10 counts between benign, borderline and malignant serous tumors but within the mucinous group of neoplasms there was considerable overlap between the counts for borderline and malignant tumors. There was no relationship between the PC10 index and the surgical stage of the malignant neoplasms and the index could not be correlated with patient death. Staining for PCNA does not, therefore, appear to be of any prognostic value in ovarian adenocarcinomas.

Prognostic value of epidermal growth factor receptor expression in cervical carcinoma.

AIMS: To investigate the pattern of epidermal growth factor receptor expression and its prognostic value in the three main types of cervical carcinoma. METHODS: 62 cases of stage IB/IIA cervical carcinoma, all with a minimum of five years of follow up, were studied. Representative sections were stained for mucin to permit accurate tumour typing and a standard avidin-biotin immunoperoxidase technique using the polyclonal antibody 12E was used to demonstrate the presence of epidermal growth factor receptor. RESULTS: A proportion of all three tumour types expressed epidermal growth factor receptor, it being most common in squamous cell carcinomas (50%). Overall, there was a correlation between epidermal growth factor expression and mortality. This was particularly obvious in the absence of lymph node metastases. When the individual tumour types were considered this association with prognosis was not demonstrable for squamous cell carcinomas or adenocarcinomas but was a very prominent feature of adenosquamous carcinomas. CONCLUSIONS: Immunohistochemical demonstration of epidermal growth factor receptor expression may be useful in identifying those patients with a poor prognosis, particularly those with adenosquamous carcinomas which have not metastasised to the regional lymph nodes.

Use of proliferation cell nuclear antigen immunoreactivity for distinguishing hydropic abortions from partial hydatidiform moles.

AIMS: To determine whether the expression of proliferating cell nuclear antigen (PCNA) in villous cytotrophoblast could distinguish between placental tissue from a hydropic abortion and that from a partial hydatidiform mole. METHODS: Tissue from 18 partial hydatidiform moles, 15 hydropic abortions, five normal first trimester placentas and five normal full term placentas were immunostained for expression of PCNA, using the monoclonal antibody PC10. RESULTS: PCNA immunoreactivity was very much higher in the cytotrophoblast of normal first trimester placentas than in normal term placentas. Villous tissue from partial hydatidiform moles showed, on average, less immunoreactivity for PCNA than did villous tissue from hydropic abortions. CONCLUSIONS: Immunostaining for PCNA is of no value for differentiating between partial hydatidiform moles and hydropic abortions. The findings indicate that trophoblastic proliferation or hyperplasia is not a feature of partial hydatidiform moles.

Cathepsin-D expression in cervical carcinoma and its prognostic significance.

An immunohistochemical study was made of cathepsin-D protein expression in each of the three main types of uterine cervical carcinoma (squamous carcinoma, adenosquamous carcinoma and adenocarcinoma) with particular reference to lymph node status and prognosis. Of the 61 cases, 54.1% showed cytoplasmic staining in more than 2.5% of tumour cells counted. Cathepsin-D expression was significantly higher in adenocarcinoma (mean -3.128) than in squamous carcinoma and adenosquamous carcinoma (mean -3.709, p = 0.047 using logit transformation). Cathepsin-D had no prognostic value in any of the three tumour types. No relationship was found between cathepsin-D staining and lymph node status and there was no advantage in adding cathepsin-D values to lymph node status. These results suggest that immunostaining for cathepsin-D protein expression is unlikely to be of use as a prognostic marker.

Carcinoma of the cervix: an analysis of prognostic factors, treatment and patterns of failure following Wertheims hysterectomy.

A clinicopathologic analysis of 70 patients treated by radiotherapy and/or chemotherapy following primary radical surgery has been undertaken. Clinical stage at presentation was IB (58 patients) and IIA (12 patients). Thirty-five patients (50%) had squamous carcinoma, 23 (33%) had adenosquamous carcinoma, 9 (13%) had adenocarcinoma and 3 (4%) had an undifferentiated neoplasm. The reasons for further treatment were: (i) pelvic lymph node metastases (PLNM), 35 (50%); (ii) inadequate central clearance (ICC), 13 (18%); (iii) recurrent disease (RD), 17 (24%); (iv) others, 5 (8%) cases. Sixty-seven patients had radiotherapy, one of whom also received adjuvant chemotherapy, three patients had chemotherapy alone, and 12 patients received chemotherapy for recurrence following radiotherapy. The 5-year survival in the above referral groups were: (i) 66%; (ii) 62%; (iii) 12%. The site of relapse following treatment was primarily pelvic in groups 2 (ICC) and 3 (RD) and extrapelvic in group 1 (PLNM). Of the histologic parameters studied the only factor of statistical significance in predicting outcome in this group who are recognized to have a generally poor prognosis was the presence of parametrial extension (P = 0.0066). Six cases (9%) developed complications following therapy, lymphoedema being the most common (66%).

Prognostic value of c-erbB-2 expression in uterine cervical carcinoma.

AIMS: To study the pattern of expression and prognostic importance of c-erbB-2 protein in cervical carcinoma. METHODS: Sixty two cases of stage IB/IIA cervical carcinoma, representing the three main tumour types, were investigated immunohistochemically for the presence of c-erbB-2 protein expression, using a monoclonal antibody (CB11) to its internal domain. Follow up of at least five years' duration was available in all cases. RESULTS: Definite membrane staining was seen in 38.7% of cases. There was a strong correlation with poor survival (p less than 0.0001) particularly. For those with adenocarcinomas, this was the case when nodal metastases were present. In contrast, for squamous carcinomas and adenosquamous carcinomas, the association with a poor prognosis was most apparent in those patients without lymph node metastases. CONCLUSIONS: These findings raise the possibility that immunostaining for c-erbB-2 protein could be used as a prognostic marker and may help identify those patients for whom early adjuvant treatment might be beneficial.

Cervical carcinoma: a hazard model in early stage disease.

The 235 patients with stage IB/IIA cervical carcinoma treated by Wertheim's hysterectomy, as a primary procedure, at St Mary's Hospital, Manchester between 1975 and 1989 inclusive, form the basis of this study. Using Cox's regression model, four variables were shown to have independent prognostic significance. These were: (1) lymphatic permeation (adjacent to the tumor); (2) tumor volume; (3) being pregnant at diagnosis and (4) lymph node metastases. A heuristic model was formulated which was based upon these four factors and by using this information it was possible to separate the patients into four distinct prognostic groups. It is suggested that this model may prove useful in identifying those patients at a higher risk of dying of disease and who would benefit from early adjuvant systemic therapy.