Sudden death due to a laryngeal cyst.

A 68-year-old woman died suddenly at home; her body was found in an armchair in a sitting position. Autopsy revealed a laryngeal cyst of a dilated secretory gland, located above the vocal cords, which obstructed the glottis, causing asphyxia. A review of the literature with forensic implications is given.

Bacterial endocarditis in a transplanted heart.

A 51-year-old man presented with an abscess in his sternotomy scar 33 months after orthotopic heart transplantation. After surgical drainage he developed a febrile illness which led to renal and pulmonary failure. Twenty-three days after the illness began, blood cultures grew Staphylococcus aureus and he died 11 days later. Post-mortem examination revealed acute bacterial endocarditis with dense colonies of gram-positive cocci on the mitral valve leaflets and microabscesses in the myocardium of the transplanted heart.

Bone changes in mice after prolonged continuous exposure to a high concentration of carbon monoxide.

Quantitative and qualitative pathological changes in mouse bones are described after continuous exposure to 0.24% v/v of carbon monoxide in air for periods of up to 180 days. Planimetric measurements of five bones (parietal bone, sternum, lumbar vertebrae, ribs and shafts of femurs) showed a considerable increase in the amount of bone tissue in all bones except the femurs. The greatest amount of new bone formation was found, in decreasing order, in the skull, ribs, lumbar vertebrae and sternal segments. The cortex of the femur shafts showed some thinning, although there was more trabecular bone in the metaphyses. At the same time an expansion of marrow cavities was found in ribs, parietal bones and femurs. Possible pathomechanisms responsible for the excessive bone formation are explored. It is suggested that an increased rate of blood flow through the bone and marrow tissues played an important role.

The cancer research campaign (King's/Cambridge trial for early breast cancer: clinico-pathological aspects.

Analysis of pathological data in the 10th year of follow-up of a multicentre trial of the management of operable breast cancer has confirmed the correlation of prognosis with tumour grade, tumour size and lymph-node status. For each factor examined there was no difference in survival between the 2 treatment groups ("watch policy" and radiotherapy) but patients in the WP group whose tumours were of Grade II or III or greater than 2 cm, or with lymph-node metastases, had a greater chance of local recurrence. Cellular reaction had no relationship with prognosis, except in patients with Grade III tumours. The clinical relevance and application of these results are discussed.

Effects of environmental temperature on haemopoietic stem cells in the tails of mice.

Using the endogenous spleen colony assay method of Till & McCulloch (1963), the numbers of haemopoietic stem cells present in the bone marrow in the tails of mice were estimated under different environmental temperatures. Compared to animals kept at 22--26 degrees C, mice transferred to an kept at 36.5 degrees C showed a doubling of colony-forming units in the tail in 1--4 weeks. Exposing them to 8 degrees C caused a significant depopulation to approximately one-third in 3--4 weeks. By transferring the mice from one temperature extreme to another these changes could be reversed. Tail marrow depleted of viable stem cells by X-irradiation was repopulated within approximately 3 weeks in animals kept at room temperature or above but this process was inhibited in the cold.

The effect of chemotherapy on occult metastases after surgical removal of a non-immunogenic mouse carcinoma.

A transplantable non-immunogenic murine carcinoma of spontaneous origin, WHT Carcinoma N-C (Hewitt), was used to assess the effectiveness of melphalan (Ml) and/or methotrexate (Mx) for treatment of occult metastatic disease following surgical excision of primary tumors. Early surgical excision alone cured 66% of mice; later excision gave no cures. Maximum sublethal doses of chemotherapy rarely cured mice of metastases but did extend their survival time by up to 66% as compared with mice subjected to excision only. The influence of excision and chemotherapy on the frequency of local recurrence or pulmonary metastasis is discussed. Extrapulmonary metastases were 2.5 times more frequent in long-term than in short-term survivors, independently of treatment.

Prostaglandins and breast cancer.

Malignant human breast tumours produced more prostaglandin-like material during homogenisation than did benign tumours or normal breast tissue. Greatest synthesis in vitro occurred with tumours associated with bone metastases, and the highest "basal" amounts tended to occur in tumours showing spread histologically. It is suggested that prostaglandins may play a part in tumour spread and growth in bone and that drugs which inhibit prostaglandin synthesis may be valuable therapeutic agents in cancer.

Adaptation of mice to carbon monoxide and the effect of splenectomy.

The adaptation of normal and splenectomized mice to increasing concentrations of carbon monoxide (CO) in air, and their subsequent long-term survival in it were studied. From the 10th day onwards the concentration of CO was maintained at 0.24%, which produced a carboxyhaemoglobin level of about 74% in the blood, and which was normally lethal within 24 h. However, the non-splenectomized mice survived in this envirment for an average of 47 days, but splenectomized moce survived for 101 days. During adaptation to CO there were marked increases in the haematocrit level and the concentration haemoglobin, a massive release of reticulocytes into the circulation, and increases in blood volume, spleen and heart weight. However, changes in the above haematological parameters were significantly less in splenectomized than in normal animals. These differences were attributed to the loss of the erythropoietic reservees of the spleen. In splenctomized mice which survived for over 90 days in CO there was histological evidence for the development of extramedullary erythropoiesis, as well as increased erythropoietic activity in the marrow of the tail vertebrae, which occurred earlier. Deaths were most frequently associated with massive internal haemorrhages in both groups of animals. This is discussed in relations to histological and haematological findings. Also in both groups, there was evidence that both hypertrophy and hyperplasia of heart muscle fibres occurred during adaptation to breathing CO.