Molecular and cell biologic aspects of erythropoiesis in long-term bone marrow cultures

In long-term marrow cultures, proliferation and differentiation of hemopoietic stem cells occurs for several months. Normally, only the most primitive erythroid progenitor cells are produced (the BFU-E). Following treatment with anemic mouse serum (AMS) or normal mouse serum plus erythropoietin, the BFU-E mature into CFU-E, which then go to produce mature nonnucleated red cells. This development is associated with the production of adult type hemoglobin. Furthermore, erythropoiesis and granulopoiesis occur in association with discrete cellular elements of the adherent cell layer in the long-term culture. Following treatment with AMS, erythropoiesis is enhanced while granulopoiesis is depressed, with no apparent competition at the stem cell or progenitor cell level.     

Evidence of a Strong Association Between Frequency of Self-Monitoring of Blood Glucose and Hemoglobin A1c Levels in T1D Exchange Clinic Registry Participants

OBJECTIVE

Despite substantial evidence of the benefit of frequent self-monitoring of blood glucose (SMBG) in type 1 diabetes, certain insurers limit the number of test strips that they will provide. The large database of the T1D Exchange clinic registry provided an opportunity to evaluate the relationship between the number of SMBG measurements per day and HbA_1c levels across a wide age range of children and adults.

RESEARCH DESIGN AND METHODS

The analysis included 20,555 participants in the T1D Exchange clinic registry with type 1 diabetes ≥1 year and not using a continuous glucose monitor (11,641 younger than age 18 years and 8,914 18 years old or older). General linear models were used to assess the association between the number of SMBG measurements and HbA_1c levels after adjusting for potential confounding variables.

RESULTS

A higher number of SMBG measurements per day were associated with non-Hispanic white race, insurance coverage, higher household income, and use of an insulin pump for insulin delivery (P < 0.001 for each factor). After adjusting for these factors, a higher number of SMBG measurements per day was strongly associated with a lower HbA_1c level (adjusted P < 0.001), with the association being present in all age-groups and in both insulin pump and injection users.

CONCLUSIONS

There is a strong association between higher SMBG frequency and lower HbA_1c levels. It is important for insurers to consider that reducing restrictions on the number of test strips provided per month may lead to improved glycemic control for some patients with type 1 diabetes.The advent in the 1980s of meters for self-monitoring of blood glucose (SMBG) has had a substantial impact on the management of type 1 diabetes (1). Several studies have demonstrated a strong correlation between frequency of SMBG and glycemic control (2–5). However, acceptance of the value of frequent SMBG has not been universal and many insurers limit the number of test strips that they will provide to four to six strips per day. In the past year, the Washington State Healthcare Authority questioned whether sufficient evidence is available to justify unlimited coverage of SMBG test strips for patients with type 1 diabetes (6).The large database of the T1D Exchange clinic registry provided an opportunity to evaluate the relationship between the number of SMBG measurements per day and HbA_1c across a wide age range of children and adults, and to evaluate factors associated with the number of SMBG measurements per day.     

Is the prevalence of pre-eclampsia affected by HIV/AIDS? A retrospective case–control study

Objective

To evaluate the rate of HIV/AIDS (and CD₄ levels) in women with pre-eclampsia compared to that of a control group.

Methods

This was a retrospective case–control study in a tertiary and regional hospital in South Africa. We reviewed the hospital records of women who had delivered in these hospitals between 1 January 2008 and 30 June 2010. The records of women with pre-eclampsia during the study period were analysed. Their HIV infection rate was compared to that of a control group consisting of normotensive healthy pregnant women.

Results

Among 492 cases of pre-eclampsia, 130 (26.4%) were HIV infected. In the control group, 183/500 (36.6%) were HIV infected (p = 0.001, OR = 0.62, 95% CI: 0.47–0.82). After adjustment to match the difference in maternal age and parity, the rate of HIV/AIDS was lower in the pre-eclamptic group than in the control group (p = 0.005, OR = 0.658).

Conclusion

The rate of HIV/AIDS was significantly lower in women with pre-eclampsia than in normotensive healthy pregnant women.     

Rotator cuff sonography: a reassessment

This study is both a retrospective and prospective evaluation of the clinical usefulness of shoulder sonography. Ninety-eight patients suspected of having rotator cuff tears underwent sonography of both shoulders. Sixty-two patients underwent double-contrast arthrography performed on the same day as sonography, and 38 patients underwent surgery after sonography. A comparison of the results from ultrasound and arthrography, using published diagnostic criteria, demonstrated a sensitivity of 75% and a specificity of 43% for detection of a rotator cuff tear. In this study, use of more restricted criteria, a subset of the published criteria, yielded a sensitivity of 68% and a specificity of 90%. A comparison of sonography with surgery, using this study's criteria, demonstrated a sensitivity of 57% and a specificity of 76%. This report shows that shoulder sonography is less reliable than previously reported and appears to have a very limited role in the evaluation of rotator cuff injuries.     

Organization of intrinsic connections in owl monkey area MT

Area MT (middle temporal) is a well-defined visual representation common to all primates, which shows a clear selectivity to the analysis of visual motion. In the present study we examined the architecture of the intrinsic connections in area MT in an attempt to reveal its organizing principles and its potential relationship to the functional domains in area MT. Intrinsic connections were studied by placing small injections of the tracer biocytin in area MT of seven adult owl monkeys (Aotus nancymae). The injections were targeted at well-defined orientation domains revealed using optical imaging of intrinsic signals. The distribution of axons labeled by these injections was related both to the cytochrome oxidase histochemistry and to the layout of functional domains in area MT and surrounding tissue. Tracer injections in the superficial layers of area MT produced a complex network of extrinsic and intrinsic axonal connections. Clear instances of extrinsic connections were observed between area MT proper and the MT crescent situated postero-medially to it. The intrinsic connections were laterally spread and organized in patch-like clusters with an average distance from injection center to the furthest patch of 1.8 +/- 0.55 mm (+/-SD, n = 9). The overall axonal distribution tended to be anisotropic, i.e. the patches were distributed within an elongated ellipse [average anisotropy ratio: 1.86 +/- 0.66 (+/-SD)] and were asymmetrically distributed about either side of the injection site [average asymmetry ratio: 2.3 +/- 0.7 (+/-SD)]. Finally, there was a tendency for the intrinsic connections to connect to functional domains of similar orientation preference in area MT. However, this tendency varied substantially between individual cases. The highly specific nature of MT lateral connections puts clear constraints on models of surround influences in the receptive fields of MT neurons.      

4-S-(5-酰氨基-1,3,4-噻二唑-2-基)-4-脱氧-4′-去甲基表鬼臼毒素衍生物的合成与抗肿瘤活性

基于在4′-去甲基表鬼臼毒素母核C₄位上联结含有杂原子的芳香环取代基,以此考察其结构与活性关系的设想,设计并合成了10个标题化合物。体外L₁₂₁₀白血病细胞与KB细胞生长抑制试验结果表明,这类化合物有较强的抗肿瘤活性。其中化合物SIPI-92-1772,1774,1775,1776,1777与1779的活性超过临床用药依托泊甙。其余化合物活性与依托泊甙相当或略低。