A study of the relationship between ambient lead and blood lead among lead battery workers

 Objective: To examine the relationship between ambient lead levels and blood lead levels and to explore the modifiers of the relationship between ambient lead and blood lead. Method: A cross-sectional study was conducted in two lead battery factories. Blood lead level and ambient lead concentration were measured for each participant concurrently. A structured questionnaire was administered to collect sociodemographic characteristics and occupational history. Design: Biological and personal environmental measurements of 219 lead-exposed workers were analyzed by both simple and multiple linear regression. A regression model was selected for interpretation. Results: A high correlation (r=0.62) between ambient lead (PbA) and blood lead (PbB) was observed. In addition, numerous factors, including age, sex, alcohol consumption, personal hygiene practice and type of lead exposure, were also found to influence blood lead levels. Although PbB was highly correlated with PbA, blood lead level may not be effectively lowered by reducing ambient lead level. Based on the regression coefficients, improvement of hygienic practice was more effective at lowering PbB than reducing ambient lead level. Good hygienic practice may be the preferential way to reduce lead exposure in current conditions. Conclusion: Education of correct work practice may be more important than engineering control in the developing countries to lower blood lead levels in lead battery factories. Received: 28 May 1996/Accepted: 30 August 1996     

非程控降温,—80℃冻存自体外周血干细胞的研究

目的：观察非程控降温、－80℃冻存的方法对自体外周血十细胞（APBSC）的保存效果。方法：以6％羟乙基淀粉（HES）、5％二甲基亚砜（DMSO）及4％人血白蛋白（ALB）的混合物为冷冻防护剂，将APBSC直接置于－80℃下保存，冻存前反复苏后测定APBSC的CFU－GM、BFU－E；观察移植后造血功能重建情况。结果：13例患者白细胞在十3～＋7天下降至（0．0～0．1）×10／L，白细胞（0．0～0．2）×109／L持续时间3～6天，于＋9～＋11天恢复至1．0X109／L以上．中性粒细胞绝对值（ANC）于＋9～＋11天达到0．5X109／L。血小板在＋3～＋7天下降至（2．0～21）×109／L，于＋8～＋15天恢复至20×109／L以上。CFU－GM、BFU－E回大率分别为76．5％、78．4％。结论：非程控降温、－80℃冻存是一简便、经济、有效的自体外周血于细胞保存方法。     

MRI诊断腰椎间盘术后粘连和突出复发

失败的下腰椎手术是个复杂的问题，由于其症状和体征不典型，单靠临床检查很难明确诊断，而脊髓造影和常规ＣＴ等检查也很难区别突出复发和硬膜外粘连。本文分析了３２例再手术患者ＭＲＩ图象，并与第二次手术所见对比，发现２７例ＭＲＩ诊断准确，３例假阳性，２例因信号缺失不能明确诊断。     

Calcification and ossification of chronic encapsulated intracerebral haematoma: case report.

We report a case of calcified chronic encapsulated intracerebral haematoma (ICH) in a 29-year-old female who presented with progressive left sided weakness and intermittent seizures since childhood. The preoperative magnetic resonance (MR) imaging of the head initially suggested that a partially thrombosed aneurysm or vascular malformation was present. However, no vascular stain was found on the digital subtraction angiography (DSA) of both the carotid and vertebral arteries. The excised mass was histologically diagnosed as a chronic ICH. We traced the patient's medical history and found that at the age of one she sustained a head injury after a fall. So far, to our knowledge, no case of epilepsy secondary to a calcified chronic encapsulated ICH occurring 28 years after head injury has been reported. Calcified chronic encapsulated ICH concomitant with new bone formation within is even rarer. The possible pathogenesis of this case is discussed.     

4-Aminopyridine induces the release of neuropeptide Y (NPY) to produce an atropine- and tetrodotoxin-resistant contraction in rabbit isolated jejunum

4-Aminopyridine (4-AP) induced an atropine- and tetrodotoxin (TTX)-insensitive contraction (resistant contraction), in a concentration-dependent manner, in the isolated jejunum of rabbits. The failure of specific antagonists of histamine, serotonin and substance P to affect this resistant contraction ruled out the participation of histamine, serotonin and/or substance P. Antiserum against neuropeptide Y (NPY) reduced this resistant contraction in a concentration-dependent manner and inhibited the action of 4-AP totally at a high concentration (1.25% dilution) whereas normal serum lacked this ability. This suggested that the release of NPY was involved in this 4-AP-induced resistant contraction. Radioimmunoassay of NPY-like immunoreactivity in isolated synaptosomal preparations indicated that 4-AP possessed the ability to induce the release of NPY. However, guanethidine did not affect the actions of 4-AP, indicating that NPY is released mainly from non-adrenergic nerves. Our results indicate that 4-AP induces the release of NPY from non-adrenergic nerves to produce an atropine- and TTX-resistant contraction in the isolated jejunum of rabbits.     

Monokines produced by macrophages stimulate the growth of osteoblasts

We have previously reported that the J774A.1 macrophage-like tumor cell line produces two potent monokines which stimulate the growth of osteoblasts and chondrocytes. These growth factors, which have an affinity for heparin-agarose, have been termed HEP I (a 30 Kd PDGF-like molecule) and HEP II (an approximately 20 Kd molecule), respectively, based on their elution profile. Unlike HEP I, HEP II does not stimulate the growth of fibroblasts. Extensive biological and chromatographic studies disclosed that HEP II appears to be a unique bone cell mitogen unlike any known growth factor, including the FGFs, IL-1s, and TNFs, EGF, IGF-I and -II, TGF-beta, beta 2 microglobulin, G-CSF, CSF-1 and GM-CSF. To characterize more fully the effects of the macrophage-derived monokines on osteoblast growth and function, clones were derived from calvaria explant cultures. Two clones, SDFRC-2.05 and SDFRC-3, were developed and found to exhibit osteoblastic characteristics, including high levels of alkaline phosphatase, synthesis of type I but not type III collagen, and an increased intracellular cAMP production in response to PTH. The SDFRC-3 cells exhibited a polygonal morphology like that of the explant-derived cells while SDFRC-2.05 cells exhibited a more fibroblastic morphology. When tested on the explant cultures and clones, HEP I and HEP II were found to stimulate DNA synthesis and increase protein per culture, but decreased alkaline phosphatase activity. Clone SDFRC-3 was found to be more responsive to HEP II than clone SDFRC-2.05. Both monokines were found to be more potent mitogens for bone cells than TGF-beta. HEP II, but not HEP I or TGF-beta, induced a transformation of bone cells from a polygonal to a fibroblastic morphology, suggesting the induction of migration prior to proliferation. Thus, macrophages may be responsible not only for bone repair but also for ensuring the linkage of bone formation to resorption during physiological remodeling.     

The use of axial-pattern cutaneous and musculocutaneous flap transposition in the reconstruction of deep burns

From June 1979 to July 1987, 84 acute burned patients with localized deep wounds involving tendon, nerve, vessel, bone and joint were treated by utilising 26 types of island axial-pattern cutaneous or musculocutaneous flaps. All flaps survived completely with a primary healing rate of 91.4%. All patients were divided into 'urgent' (within 48 hours), 'early' (within 2 weeks), or 'infected' groups according to the time interval between the burn injury and the surgery conducted. The primary healing rates for each groups were 100%, 94%, and 86% respectively. No significant differences exist between the axial-pattern cutaneous flap and musculo-cutaneous groups. The measures for minimizing infection including thorough debridement, groups. The measures for minimizing infection including thorough debridement, avoiding of circulatory compromises of the flaps, effectively postoperative drainage, and the use of antibiotics were discussed. Four types of newly developed axial-pattern cutaneous flaps as well as a super-long latissimus dorsi-external oblique abdominis-rectus abdominis combined musculocutaneous flaps were presented.