Effects of tamoxifen on normal breast tissue histological composition: Results from a randomised six-arm placebo-controlled trial in healthy women

Tamoxifen prevents recurrence of breast cancer and is suggested for preventive risk-reducing therapy. Tamoxifen reduces mammographic density, a proxy for therapy response, but little is known about its effects in remodelling normal breast tissue. Our study, a substudy within the double-blinded dose-determination trial KARISMA, investigated tamoxifen-specific changes in breast tissue composition and histological markers in healthy women. We included 83 healthy women randomised to 6 months daily intake of 20, 10, 5, 2.5, 1 mg of tamoxifen or placebo. The groups were combined to “no dose” (0-1 mg), “low-dose” (2.5-5 mg) or “high-dose” (10-20 mg) of tamoxifen. Ultrasound-guided biopsies were collected before and after tamoxifen exposure. In each biopsy, epithelial, stromal and adipose tissues was quantified, and expression of epithelial and stromal Ki67, oestrogen receptor (ER) and progesterone receptor (PR) analysed. Mammographic density using STRATUS was measured at baseline and end-of-tamoxifen-exposure. We found that different doses of tamoxifen reduced mammographic density and glandular-epithelial area in premenopausal women and associated with reduced epithelium and increased adipose tissue. High-dose tamoxifen also decreased epithelial ER and PR expressions in premenopausal women. Premenopausal women with the greatest reduction in proliferation also had the greatest epithelial reduction. In postmenopausal women, high-dose tamoxifen decreased the epithelial area with no measurable density decrease. Tamoxifen at both low and high doses influences breast tissue composition and expression of histological markers in the normal breast. Our findings connect epithelial proliferation with tissue remodelling in premenopausal women and provide novel insights to understanding biological mechanisms of primary prevention with tamoxifen.     

Brain tissue microarrays in dementia research: White matter microvascular pathology in Alzheimer's disease

Tissue microarrays (TMA) consist of up to 1000 cylindrical tissue cores from different donor paraffin blocks relocated into one recipient block, allowing for efficient histopathological studies by fluorescence in situ hybridization, RNA in situ hybridization or immunohistochemistry. On the background of the increasing interest of the TMA technique in cancer research and the suggestion of its application also in studies of non‐neoplastic intracranial disorders, the technique was applied to pathologic white matter in AD brains. Eight cases with AD and concomitant white matter pathology were neuropathologically diagnosed on whole brain coronal slides. The TMA technique was used to grade severity of white matter pathology and to quantify small vessels with traditional staining and immunohistochemical markers. These measurements were compared with the whole brain neuropathological assessment. The technique produced good results with preserved tissue structures as confirmed by the whole brain evaluation. Severity of white matter pathology evaluated on the TMA cores correlated negatively with small vessel quantities, and statistically significant differences in vessel quantities paralleled different grades of white matter pathology. It is concluded that the TMA technique could be further utilized in studies of dementing disorders, and may have its advantages in large, clinically well‐characterized materials (e.g. in quantitative mapping of white matter changes).     

Tissue expression of the tumour associated antigen CA242 in benign and malignant pancreatic lesions. A comparison with CA 50 and CA 19-9

The expression of a novel tumour associated antigen CA 242, defined by the monoclonal antibody C 242, was studied by immunoperoxidase staining in formalin-fixed, paraffin-embedded tissue sections from normal pancreata, pancreata with pancreatitis and benign and malignant pancreatic neoplasms. The antigenic determinant of the C 242 antibody is a sialylated carbohydrate structure, related but chemically different from tumour marker antigens CA 19-9 and CA 50. Thirty-eight of 41 (93%) well to moderately differentiated ductal adenocarcinomas of the pancreas and all cystadenocarcinomas were positive for CA 242. The staining was most intense in the apical border of the cells, and in the intraluminal mucus. Only two out of seven poorly differentiated adenocarcinomas stained, and the number of positive cells was smaller than in well differentiated carcinomas. Only occasional cells were stained in one out of five anaplastic carcinomas. Part of large ducts were positive in 91% (21/23) specimens of chronic pancreatitis. In acute pancreatitis small terminal ducts, centro-acinar cells and some large ducts stained for CA 242. In normal pancreas only a few small terminal ducts were CA 242 positive. Carcinomas always stained more strongly for CA 242 than normal pancreatic tissue adjacent to the carcinoma. The results of CA 242 are compared with those of tumour marker antigens CA 50 and CA 19-9. Serum CA 242 levels were determined in 23 of the patients with pancreatic cancer using a fluoroimmunoassay. Fifteen (65%) patients had an elevated value. There was no clear-cut correlation between the serum levels and the immunohistochemical expression of the CA 242 antigen. The expression of CA 242 in pancreatic tissue resembles that of CA 50 and is similar to CA 19-9. The antigen is expressed in serum of many patients with pancreatic cancer and, therefore, is a potential candidate for a serum tumour marker.     

Primary lymphocytes as predictors for species differences in cytotoxic drug sensitivity.

Several in vitro methods have been suggested to predict drug-induced haematotoxicity and species differences; the most commonly used being the clonogenic CFU-GM assay. The aim of the current study was to evaluate whether primary lymphocytes from peripheral blood, assayed with a short-term non-clonogenic assay, could be used to detect species differences in drug sensitivity, and offer an alternative to the CFU-GM assay. The effect of 17 different cytotoxic drugs on lymphocytes from human, dog, rat and mouse was evaluated. A higher sensitivity of human than mouse lymphocytes was seen for topotecan and for 3 of 5 antimetabolites tested. Clear species specificity was also seen for the proteasome inhibitor bortezomib where rodent cells were 50-300 times less sensitive than human cells. Good agreement between our data and published CFU-GM data was observed, suggesting that primary lymphocytes may be a useful model for species difference screening in drug development.     

Tarsal tunnel syndrome in runners.

Tarsal tunnel syndrome has only recently been noted to be a cause of foot and ankle pain in runners. The tarsal tunnel is located just posterior to the medial malleolus and may compress the posterior tibial nerve as it passes through it, producing numbness and paraesthesia in the foot. While the aetiology of this condition is frequently multifactorial, abnormal foot and ankle mechanics and excessive training tend to be the most commonly cited aetiological factors. Successful treatment of tarsal tunnel syndrome requires an accurate diagnosis by differentiating it from plantar fasciitis and Achilles tendinitis and then making proper biomechanical and training changes in the runner. Conservative treatment is generally successful, but occasionally surgical treatment is required to decompress the nerve.     

Tension leads to increased neutrophil accumulation and decreased laparotomy wound strength

Wound margin strength was measured immediately after and at 72 hours after median laparotomy in rats. The laparotomy wound was sutured with or without tension, and wound margin strength was measured as breaking strength with the sutures in situ. In wounds sutured without tension, no decrease in breaking strength was observed at 72 hours; in rats sutured with tension, breaking strength decreased by 77%, and in almost half of the animals the sutures cut through. There was markedly increased accumulation of neutrophil leukocytes around the sutures in the tension group, as indicated by increased tissue myeloperoxidase activity. The decrease in breaking strength was abolished by treatment with an inhibitor of the collagen-degrading proteinases of the neutrophils (the soybean trypsin inhibitor). Although the decrease in breaking strength should be due to collagenolysis, there were no changes in collagen content or solubility around the sutures, indicating that the changes in collagen were too delicate to be revealed by the methods used. We conclude that the decrease in breaking strength was caused by the neutrophils.     

A tobacco quit and win model in the Stockholm cancer prevention programme.

The main objective of the Stockholm Cancer Prevention Programme (SCPP) is to reduce cancer incidence and mortality among the 1.6 million inhabitants in Stockholm county by reducing risk factors particularly related to lifestyle. The objective of the SCPP's tobacco action programme is to reduce the number of adult daily users of tobacco (including oral snuff) to 20% by the year 2000. In 1988, a nationwide Quit and Win contest was conceived as part of this long-term programme. The contest recruited nearly 13,000 participants or 0.6% of the daily tobacco users in Sweden over the age of 16 years. More than 60% of the participants were recruited from Stockholm county. This corresponds to 1.9% of the daily tobacco users in Stockholm county compared with 0.3% in the rest of Sweden. The pharmacies and the public health services organizations were the principal distributors of contest entry forms. Sixty-two percent of the men and 59% of the women were tobacco free one month after the contest, and after 6 months the corresponding figures were 30 and 25%, respectively.     

The sequence of development of intestinal tissue injury after strangulation ischemia and reperfusion

Tissue injury at reperfusion has been reported after partial ischemia. However, previous attempts to demonstrate a component of injury caused by reperfusion after total ischemia have failed. This study was performed to evaluate the hypothesis that in such situations the extent of the tissue injury caused by ischemia itself prevented detection of a reperfusion component. Rats were subjected to near-total intestinal ischemia by means of a hydrostatic pressure clamp that produced preferential venous occlusion (strangulation) for periods from 1 to 90 minutes. Tissue injury was evaluated microscopically by a blinded examiner. Ischemic periods of 20 minutes or less did not induce detectable tissue injury. Longer durations of ischemia caused villous injury: the longer the period of ischemia, the more extensive the tissue injury. However, there was no exacerbation of injury seen after reperfusion, regardless of the duration of ischemia. In a separate series of rats, total arterial occlusion was employed without concomitant venous congestion. Such isolation arterial occlusion of 40 to 60 minutes' duration was followed by a statistically significant exacerbation of tissue injury at reperfusion. Thus total intestinal ischemia may be followed by reperfusion injury if there is no concomitant congestion and if ischemic injury is not too extensive.     

Liver metabolic effects of intestinal shock and naloxone treatment in the rat

The liver metabolic response of rats following a standardized intestinal shock, induced by applying a pressure of 120 cm water on the mesenteric vessels for 60 min, was studied. Immediately prior to the release of the pressure on the vessels saline or naloxone was given either as a single injection or as a continuous infusion. After the reperfusion of the intestine no early disturbances in liver metabolism were found as evidenced from the ATP, glucose and lactate levels in liver biopsies taken 15 min following reflow. Within 60 min of reflow reduction of ATP and increases of glucose and lactate levels occurred. There were no major hemodynamic or liver metabolic differences between saline- and naloxone-treated shocked rats. When saline or naloxone was given as a continuous infusion, the changes in liver metabolism were, however, less severe than those observed in the single injection situation pointing toward a non-specific effect of volume replacement rather than a blockade of opioid receptors. Hepatic hypoxia and/or cellular effects of "shock factors" could be mechanisms of pathophysiologic importance for the disturbed liver metabolism in this shock model.     

Dissecting karyotypic patterns in renal cell carcinoma: an analysis of the accumulated cytogenetic data

Molecular cytogenetic analysis frequently shows human papillomavirus (HPV) integration near translocation breakpoints in cervical cancer cells. We have recently described a cluster of HPV18 integrations in the distal end of the common fragile site FRA8C at 8q24 in primary cervical carcinoma samples. Chromosome band 8q24 contains the MYC gene (alias c-MYC), FRA8C, and FRA8D. The MYC gene is frequently deregulated--usually by translocation or amplification--in various tumor types. In the present study, we performed a molecular cytogenetic analysis of HPV18 integration patterns and the 8q24 translocation in a primary cervical carcinoma and in HeLa cells using combined binary ratio-fluorescence in situ hybridization. Our aim was to determine how the chromosomal breaks involved in these events relate physically to the MYC gene; whether they map to the FRA8C site, the FRA8D site, or both; and how they correlate with the occurrence of DNA flexibility domains. The 8q24 translocation breakpoints mapped between stretches of integrated HPV18 sequences in the distal end of FRA8C. This region contained DNA helix flexibility clusters, several of which mapped in the vicinity of HPV integration sites and translocation breakpoints in cervical carcinomas. DNA helix flexibility clusters were also found near known MYC translocation breakpoints in Burkitt lymphomas (BL), but most BL breakpoints mapped clearly outside FRA8C. Our data revealed that FRA8C is involved in HPV integration and chromosomal translocations in cervical carcinoma; however, this fragile site is not involved in classical MYC translocations in most BLs. In the context of the familial nature of cervical cancer, FRA8C may be considered a candidate susceptibility region for cervical carcinoma.