微小染色体维持蛋白与肿瘤的研究进展

微小染色体维持(MCM)蛋白家族是一类从太古代生物到高等真核生物广泛存在的高度保守的蛋白质。MCM蛋白与其他相关因子相互影响,共同在DNA复制、延长、转录及修复过程中发挥作用。MCM蛋白在细胞周期中异常高表达意味着细胞非典型增生甚至肿瘤的发生,提示MCM蛋白可作为增殖细胞的特殊标志物,在肿瘤的诊断、预后评价、临床治疗等方面具有广泛的应用前景。     

The influence of diabetes on short-term outcome following a prosthetic above-the-knee femoro-popliteal bypass

Objectives

To assess the influence of diabetes mellitus on early morbidity and mortality following a femoro-popliteal bypass.

Methods

Clinical data on patients subjected to a prosthetic above-the-knee femoro-popliteal bypass for atherothrombotic disease over a four-year period in the Durban Metropolitan Vascular Service were culled from a prospectively maintained computerised database. The patients were divided into two groups, diabetic and non-diabetic.

Results

Two hundred and seventeen patient records were analysed; 102 (47%) patients were diabetic and 115 (53%) non-diabetic. The mean age in the two groups was almost similar. Differences noted between the two groups were that there was a higher prevalence of males and cigarette smokers in the non-diabetic group and hypertension among the diabetics. The prevalence of ischaemic heart disease in the two groups was not statistically significant. The majority of patients in both groups presented with critical limb ischaemia.Overall, 208 (96%) of the patients had their procedures performed using loco regional anaesthesia. The incidence of superficial wound infection between the two groups was not statistically significant. Deep infection, which necessitated removal of the graft, and cardiovascular complications were significantly higher in the diabetics. Four patients (3.9%) in the diabetic group and only one (0.9%) in the non-diabetic group died.

Conclusion

Diabetes mellitus significantly increases the incidence of graft sepsis and cardiovascular morbidity in patients undergoing above-the-knee femoro-popliteal bypass.     

True T-cell chronic lymphocytic leukemia: a morphologic and immunophenotypic study of 25 cases [see comments]

We studied 25 T-cell chronic lymphocytic leukemia (T-CLL) cases collected over a 15-year period. Immunophenotypic analysis was performed in each case; 12 cases were evaluated by cytogenetics, and gene rearrangement studies were performed in 14 cases. The median age was 57 years with a male predominance (M:F, 15:10). The median presenting lymphocyte count was 36.3 x 10(9)/L (range, 3.9 to 438 x 10(9)/L). Fourteen patients (56%) had shotty adenopathy and ten (40%) had mild-to-moderate splenomegaly at presentation; four (16%) had erythematous skin lesions. The lymphocytes were predominantly small; some cases had a minor component of medium-sized cells (< 10%). The nuclear: cytoplasmic ratios were uniformly high with round to oval nuclei; however, a wide spectrum of nuclear outlines could be found, ranging from minimally to markedly convoluted. Nucleoli were either absent or small and inconspicuous. These lymphocytes did not have the morphology of prolymphocytes and did not contain cytoplasmic granules. Bone marrow infiltration was generally in an interstitial pattern; the degree of involvement ranged from 15% to 90%. Immunophenotyping showed that the lymphocytes were mature T-cells with a predominant CD4+ immunophenotype. Three cases displayed a CD8+ immunophenotype. The patients were treated with a variety of chemotherapeutic regimens with only a minimal response observed in two of 20 patients. We conclude that T-CLL is an uncommon chronic lymphoproliferative disorder (CLPD) that can be morphologically similar to B-CLL, is distinct from T- prolymphocytic leukemia, and has an aggressive clinical course that is refractory to therapy. It may also be difficult to distinguish T-CLL from other T-CLPD, especially the leukemic phase of peripheral T-cell lymphoma and some cases of Sezary syndrome.     

The human spleen; a histological study in splenectomy specimens embedded in methylmethacrylate

In a series of 316 surgically removed spleens, a histological and supportive immunohistological study was performed on methylmethacrylate sections. The structure of the human white and red pulp differs from the rat spleen in many respects, e.g. the human lacks the marginal sinus and the architecture of the periarteriolar lymph sheath seen in the rat. In man, the lymphoid compartment is in both white and red pulps. In the white pulp separate periarteriolar T-cell areas contain a large lymph-vessel plexus, which was reconstructed in serial sections. The circulation in the red pulp is discussed. The area between the red and white pulp, the perifollicular zone, is not the equivalent of the marginal sinus in the rat. Its anatomy in man suggests that it is an area formed from red pulp during the expansion of new follicles. The micro-anatomy was analysed in 119 controls. In cases of traumatic rupture the white pulp showed evidence of stimulation. A pathognomonic histological picture was not found in idiopathic thrombocytopenic purpura. In haemolytic anaemia the pulp cords were engorged by erythrocytes accompanied by a decreased B/T cell ratio in autoimmune haemolytic anaemia and by an increased B/T cell ratio in congenital spherocytosis.     

A multinational study of the factorial structure and other characteristics of the Dartmouth COOP Functional Health Assessment Charts/WONCA

BACKGROUND: The 'Dartmouth COOP Functional Health Assessment Charts/WONCA' constitute a relatively new derived instrument for assessing health status that is specifically intended for use in primary care on a world-wide basis. It needs further validation in its special area of use. OBJECTIVES: Over a range of countries, social backgrounds and case mixes, our aim was (i) to examine the factorial structure of the instrument; (ii) to explore how well it was understood; (iii) to check its acceptability; and (iv) to assess the value of the pictures on the charts. METHODS: The charts themselves, accompanied by a short questionnaire about the charts, were administered to 1719 patients at eight varied types of treatment centre in Canada, Japan, Nepal and Spain. The responses to the instrument were subjected to standard factor analysis and a special Q-type principal components analysis. The responses to direct questions about the charts were compared with the answers to open-ended questions. RESULTS: Factor analysis suggested a shared factorial pattern for all sites, with the first two factors accounting for 88.5% of the variability in correlations between the charts across the sites. The individual questions were understood by most patients, but a substantial minority did not appear to grasp the underlying purpose of the instrument. The instrument was well accepted. The pictures were considered to be helpful by most respondents, especially those at the Nepal sites. The variability in the scores for the individual charts across sites was less than expected and not always in the expected direction. CONCLUSIONS: The COOP/WONCA system continues to show promise, but needs more validation.      

Mechanism of the pulmonary vasoconstrictor action of digoxin in the dog

The pulmonary vascular effects of a subarrhythmic dose of digoxin (60 micrograms/kg i.v.) were examined in the canine in situ perfused lung. Digoxin produced an increase in pulmonary vascular resistance (66.1%) and pulmonary arterial pressure (8.2 mm Hg) at 70 min after injection in the constant-flow, blood-perfused lung preparation. The digoxin-treated group exhibited higher plasma levels of norepinephrine compared with control dogs. The pulmonary vasoconstrictor response to digoxin was abolished by prior treatment with the alpha-adrenergic antagonists phenoxybenzamine and phentolamine. This vasoconstriction does not involve inhibition of synthesis or action of vasodilator prostaglandins by digoxin, as pretreatment with indomethacin did not attenuate, and even tended to increase, the pressor response to digoxin. The response was prevented by prior treatment with blockers of nonneuronal uptake of catecholamines normetanephrine and hydrocortisone, but not with cocaine, a blocker of neuronal uptake. In the lung preparation perfused with Krebs buffer solution, digoxin failed to produce vasoconstriction when administered intravenously (60 micrograms/kg) or in the perfusate at a concentration of 8 ng/ml, the blood level at the peak of the pressor response. Sodium-pump activity (ouabain-sensitive 86Rb+ uptake) of intralobular pulmonary arteries excised after 90 min of exposure to digoxin was the same as activity in arteries from control dogs. In conclusion, digoxin produces a pulmonary vasoconstriction through an alpha-adrenergic mechanism. Since the pressor response was observed only in the blood-perfused lung, blood-borne catecholamines are apparently involved.