Retroviral transduction and expression of the human alkyltransferase cDNA provides nitrosourea resistance to hematopoietic cells

Myelosuppression is the dose-limiting toxicity for nitrosourea chemotherapy. This toxicity predominantly involves modification of the O6 position of guanine with an alkyl moiety. The enzyme responsible for repair of O6-alkylguanine adducts, O6-alkylguanine-DNA alkyltransferase (alkyltransferase), is expressed at low levels in bone marrow (BM) cells. High alkyltransferase expression prevents the cytotoxicity and carcinogenicity of nitrosoureas in several transgenic and in vitro gene transfer models. We used gene transfer using a novel myeloproliferative sarcoma virus (MPSV) based retrovirus (vM5MGMT) to express the human alkyltransferase cDNA (MGMT) in human and murine hematopoietic cells. Transduced K562 cells had very high levels of alkyltransferase expression and significantly increased resistance to 1,3-bis (2- chloroethyl) nitrosourea (BCNU) as compared with untransduced K562 cells. Primary murine BM progenitors showed a high transduction efficiency with vM5MGMT and have increased BCNU resistance in vitro. After BM transplantation with vM5MGMT-transduced BM cells and BCNU treatment of these mice, BM, spleen and thymus had a 10- to 40-fold increase in alkyltransferase expression that persisted for at least 23 weeks posttransplantation. Progenitor cells procured from mice expressing high levels of alkyltransferase also had increased resistance to BCNU. Thus, an MPSV-based retroviral vector transduces mouse and human hematopoietic cells at high efficiency and results in high levels of gene expression both in vitro and in vivo. Overexpression of the alkyltransferase protein may protect hematopoietic progenitors from nitrosourea-induced myelosuppression.     

大肠癌免疫组化表达与临床病理的关系

目的:探讨大肠癌CEA、P53、nm23、Ki-67、MRP免疫组化表达特点和相互关系,及其与临床病理的关系．方法:回顾性分析2003-01／2006-07我院收治的73例大肠癌患者的临床病理及随访资料,并对其石蜡标本采用免疫组化SP染色法检测CEA、P53、nm23、Ki-67、MRP,分析其免疫组化特点及其与临床病理之间的关系．结果:CEA、P53、nm23、Ki-67、MRP在大肠癌中的阳性表达率依次为82．2％、68．5％、75.3％、84．9％和64．4％．CEA、MRP与大肠癌患者的各因素无统计学差异．P53、Ki-67和nm23与肿瘤的Dukes分期和淋巴结转移有关, P53、Ki-67在Dukes C、D期的阳性表达率(依次为82．8％和100％1明显高于Dukes A、B期者(59．1％和75．0％)(P<0．05),而nm23在Dukes C、D期的阳性表达率(58．6％)明显低于Dukes A、B期者(86．4％)(P<0．05)．CEA与nm23的表达呈明显的负相关(r=-0．296,P=0．011),而P53和Ki-67表达之间呈现明显的正相关(r= 0．308,P=0．008),其他各指标间的表达无相关性．nm23、P53和Ki-67与预后因素关系明显,nm23在生存期≥3 a患者的阳性表达率(92．9%)高于生存期<3 a者(71．2％)(P<0．05),而P53和Ki-67在生存期≥3 a患者的阳性表达率(依次为42．9％和64.3％)明显低于生存期<3 a者(74．6％和89．8％)(P<0．05)．结论:P53、Ki-67和nm23的表达与大肠癌的侵袭转移和预后密切相关．CEA可能是大肠癌的侵袭转移的促进因素．MRP所引起的耐药机制是一个相对独立的机制．CEA、P53、nm23、Ki-67可作为判断大肠癌恶性程度、侵袭转移以及预后的指标．     

Poikilocytic hereditary elliptocytosis associated with spectrin Alexandria: an alpha I/50b Kd variant that is caused by a single amino acid deletion

Hereditary elliptocytosis (HE) is a heterogeneous disorder of red blood cells frequently associated with abnormal limited tryptic digestion of the alpha I domain of spectrin and impaired spectrin dimer self- association. We studied two related individuals with poikilocytic hereditary elliptocytosis (HE) of different severity. Limited tryptic digestion of spectrin from these individuals showed the presence of a variant alpha I/50b Kd peptide at the expense of the normal alpha I/80 Kd peptide. Amino acid sequence analysis of the abnormal peptide showed that the proteolytic cleavage occurred after the arginine at position 470 of the alpha spectrin chain. Spectrin from these patients had an impaired ability to undergo self-association, as evidenced by increased amounts of spectrin dimers in 4 degrees C extracts of erythrocyte membrane from affected individuals. The polymerase chain reaction was used to study the DNA sequence of the alpha spectrin gene encoding the region of the alpha spectrin chain surrounding the abnormal proteolytic cleavage site. We detected the in-frame deletion of the trinucleotide CAT, encoding histidine 469, two amino acid residues to the N-terminal side of the abnormal proteolytic cleavage site between residues 470 and 471. Similar to many other defects of spectrin associated with HE, this deletion occurs in helix three of repeat 5 of the proposed triple helical model of spectrin repeats.     

Establishing a children's orthopaedic hospital for Malawi: A review after 10 years

Background

BEIT CURE International Hospital (BCIH) opened in 2002 providing orthopaedic surgical services to children in Malawi. This study reviews the hospital''s progress 10 years after establishment of operational services. In addition we assess the impact of the hospital''s Malawi national clubfoot programme (MNCP) and influence on orthopaedic training.

Methods

All operative paediatric procedures performed by BCIH services in the 10th operative year were included. Data on clubfoot clinic locations and number of patients treated were obtained from the MNCP. BCIH records were reviewed to identify the number of healthcare professionals who have received training at the BCIH.

Results

609 new patients were operated on in the 10th year of hospital service. Patients were treated from all regions; however 60% came from Southern regions compared with the 48% in the 5th year. Clubfoot, burn contracture and angular lower limb deformities were the three most common pathologies treated surgically. In total BCIH managed 9,842 patients surgically over a 10-year period. BCIH helped to establish and co-ordinate the MNCP since 2007. At present the program has a total of 29 clinics, which have treated 5748 patients. Furthermore, BCIH has overseen the full or partial training of 5 orthopaedic surgeons and 82 orthopaedic clinical officers in Malawi.

Conclusion

The BCIH has improved the care of paediatric patients in a country that prior to its establishment had no dedicated paediatric orthopaedic service, treating almost 10,000 patients surgically and 6,000 patients in the MNCP. This service has remained consistent over a 10-year period despite times of global austerity. Whilst the type of training placement offered at BCIH has changed in the last 10 years, the priority placed on training has remained paramount. The strategic impact of long-term training commitments are now being realised, in particular by the addition of Orthopaedic surgeons serving the nation.     

Effects of instruction by practice assistants on inhaler technique and respiratory symptoms of patients. A controlled randomized videotaped intervention study

BACKGROUND: Many patients with asthma or chronic obstructive pulmonary diseaseuse their medication inhalers incorrectly. General practitioners,pharmacists and other health care providers do not always havethe opportunity to instruct patients in correct inhaler technique. OBJECTIVE: To find out whether the inhaler technique and respiratory symptomsof patients can be improved after instruction by practice assistants. METHODS: Single blind, randomized intervention study in which 48 patientswho had been using a dry powder inhaler for at least one monthtook part. Their inhaler technique was videotaped on two visitswith a two-week interval between visits. The inhaler techniqueon the videos was subsequently scored by two experts on ninecriteria. At both visits the patients completed a questionnaireabout their respiratory symptoms. After the first video, 25patients were randomly chosen to receive instruction from oneof six practice assistants who had followed a one evening courseabout inhaler instruction, and who had been issued an instruction-set. RESULTS: The patients who received instruction had a significantly greaterreduction in number of mistakes at the second visit than thepatients who did not (P = 0.01). The instructed patients alsoreported less dyspnoea at the second visit (P = 0.03). No effectof instruction was found on wheezing, cough and sputum production. CONCLUSION: The inhaler technique of patients can be improved significantlyby the instruction of patients by trained practice assistants,possibly resulting in less dyspnoea. Keywords. Administration-inhalation, obstructive lung diseases, airways symptoms, patient-education, general practice.     

Primary tuberculous nasal polypi—A case report

Primary tuberculous pathology in nasolpolypi is a rare condition. A case of bilateral ethmoidal polypi with tubercular lesion diagnosed on histopathologlcal examination is being reported and the available relevant literature has been reviewed.     

LOW BIRTH WEIGHT BABIES : INCIDENCE AND RISK FACTORS

In a prospective hospital based study, during the period from Jan 95 to Dec 96, 3100 consecutively delivered live newborns were studied for the incidence of low birth weight neonates and to evaluate the associated risk factors. One thousand fourteen newborns were classified as low birth weight babies. The incidence expressed per 1000 live births was 327 (32.7%). Of these, 815 (80.4%) were small for gestational age neonates and 199 (19.6%) were preterm neonates. Five hundred seventy small for gestational age neonates (70%) were weighing between 2001 to 2500 gms. Mothers belonging to the age group of 19-25 years delivered the maximum number of low birth weight babies (618/1014) and of these 82.8% were small for gestational age neonates. There were 48 neonates with low birth weight born to mothers below the age of 18 years. Primiparous mothers were found to contribute higher number of low birth weight neonates (414/1014). Spacing as a factor did not show any major difference. Two hundred sixty two low birth weight neonates were born to mothers with significant obstetrical problems such as pregnancy induced hypertension, bad obstetrical history and premature rupture of membranes. The incidence of 32.7% of low birth weight babies is high enough to ring alarm bells.     

猪脑钠素及其类似物的合成

以固相多肽合成方法合成了猪的二十六肽脑钠素(BNP)和它的一个类似物(Mpr⁴,D-Ala^6,13)-BNP(4-24)-NH₂,保护肽用HF裂解除去保护基、在碱性条件下空气氧化形成二硫桥后,粗产物经凝胶过滤和高效液相色谱分离纯化,均有与天然脑钠素相同的活性。合成肽相对于树脂初始取代量的产率分别为9.56%和11.03%。