Design Characteristics for the Tissue Engineering of Cartilaginous Tissues

Tissues like the temporomandibular joint (TMJ) disc and the knee meniscus are often mistakenly viewed as a tantamount to hyaline cartilage, largely due to the absence of a comprehensive understanding of the distinguishing properties of cartilaginous tissues. Because of this confusion, fibrocartilaginous tissue engineering attempts may not be based on suitable experimental designs. Fibrocartilaginous tissues are markedly different than hyaline cartilage; however, the dearth of knowledge related to their cellular and biochemical composition, as well as their biomechanical characteristics, is stunning. Hyaline articular cartilage is exclusively composed of chondrocytes that produce primarily type II collagen, whereas the TMJ disc and the knee meniscus have a mixed cell population of fibroblasts and cells similar to chondrocytes, which predominantly secrete type I collagen. Additionally, fibrocartilaginous tissues have a low glycosaminoglycan content, a low compressive modulus, and a high tensile modulus when compared to hyaline cartilage. Therefore, it is crucial for fibrocartilaginous tissue engineering attempts to be tissue-specific, utilizing the knowledge of the distinct and unique properties of these tissues. At the same time, advances and insights related to the science and engineering aspect of hyaline cartilage regeneration must be carefully considered for the in vitro engineering of fibrocartilaginous tissues.     

Site of bone density measurement may affect therapy decision

Summary The purpose of this study was to determine whether bone mineral density (BMD) measurements at the lumbar spine and femoral neck provided comparable information to women planning to use that knowledge to help them make a decision about hormone replacement therapy. Eighty-eight healthy Caucasian women, aged 44–59 and within 0 to 5 years of menopause, participated in the study. BMD measurements were performed at the lumbar spine (L1-L4) and the femoral neck by dual energy X-ray absorptiometry (DXA). Criteria suggested by the National Osteoporosis Foundation were used to categorize women as at risk for osteoporosis, bone density more than one standard deviation (SD) below the young adult mean, or as low risk, bone density at or above this level. The re that 46 women would be classified into the low risk category on the basis of spinal BMD alone. However, 28 of these 46 women would fall into the at risk category when the femoral neck BMD was measured. Sixty-one percent of women informed they were at low risk on the basis of spinal BMD would be considered at risk based on femoral neck BMD. When femoral neck BMD was used as the primary risk indicator, 14% of the women classified as low risk would be at risk if spinal BMD were added. These results suggest that both lumbar spine and proximal femur measurements should be made when women are using bone density measurements as an aid in deciding whether or not to use hormone therapy in their postmenopausal years.     

膝骨关节病的关节镜诊断治疗

目的 通过对79例84膝骨关节病的关节镜诊断治疗回顾性总结,探讨高效率、创伤小、疗效佳的方法。方法 采用关节镜微创技术,结合术前检查对膝骨关节病分为：软骨破坏型,滑膜类型,游离体型及半月板型,依此施行有针对性,局限化手术治疗。结果 69膝得到6mo-3a的随访,按膝关节综合评分表评分,优20％,良59％,可和差21％。结论 该方法具有创伤小、康复快、并发症少等优点,在病损严重的病例,全膝置换或截骨术是进一步提高总体疗效的适宜选择。     

CT scanning and arthroscopic evaluation of patellofemoral malalignment

Ｐａｔｉｅｎｔｓｗｉｔｈｐｅｒｉｐａｔｅｌｌａｒｐａｉｎｆｒｅｑｕｅｎｔｌｙｈａｖｅｕｎｄｅｒｌｙｉｎｇｐａｔｅｌｌｏｆｅｍｏｒａｌｍａｌａｌｉｇｎｍｅｎｔ Ｅａｒｌｙｄｉａｇｎｏｓｉｓ,ｈｏｗｅｖｅｒ,ｍａｙｂｅｄｉｆｆｉｃｕｌｔｂｅｃａｕｓｅｏｆａｐｏｏｒｃｏｒｒｅｌａｔｉｏｎｂｅｔｗｅｅｎｔｈｅｐａｔｈｏｌｏｇｉｃａｌｃｈａｎｇｅｓｏｆｔｒａｃｋｉｎｇａｂｎｏｒｍａｌｉｔｉｅｓａｎｄｔｒａｄｉｔｉｏｎａｌｒａｄｉｏｇｒａｐｈｉｃｖｉｅｗｓ Ｉｎａｄｄｉｔｉｏｎ ,ｒａｄｉｏｇｒａｐｈｉｃｅｘａｍ…     

双极人工股骨头置换术治疗高龄股骨颈骨折

目的 通过对６６例７０岁以上老年人股骨颈骨折临床分析,探讨其手术可行性、术式选择。方法 回顾分析患者的术前并存症、术前准备、术式选择、麻醉方式、术中情况、术后处理及随诊情况。结果 本组无术中死亡病例,平均住院２８天,平均随访２６个月。良好率６３．６％。结论 ７０岁以上老人股骨颈骨折行双极股骨头置换术治疗是可行的。     

Differential roles of neurokinin 1 and neurokinin 2 receptors in the development and maintenance of heat hyperalgesia induced by acute inflammation

1. Following induction of acute inflammation by intraarticular injection of kaolin and carrageenan into the knee joint in rats, there was a significant decrease in the withdrawal latency to radiant heat applied to the paw (i.e. heat hyperalgesia), an increased joint circumference and increased joint temperature.
2. A neurokinin₁ (NK₁) receptor antagonist (CP-99,994, 10 mM) had no effect on the paw withdrawal latency when it was administered spinally through a microdialysis fibre before the induction of inflammation. Pretreatment with a NK₂ receptor antagonist (SR48968, 1 mM) administered spinally through the microdialysis fibre prevented the heat hyperalgesia from developing in the early stages of the inflammation.
3. Post-treatment through the microdialysis fibre with the NK₁ receptor antagonist (0.0110 mM) was effective in reversing the heat hyperalgesia. In contrast, post-treatment spinally with the NK₂ receptor antagonist (0.011 mM) had no effect on the heat hyperalgesia. The inactive stereoisomers of the NK₁ receptor antagonist, CP100,263, or the NK₂ receptor antagonist, SR48965, administered at the same doses, had no effect on the joint inflammation or the heat hyperalgesia.
4. Pretreatment systemically with the NK₁ receptor antagonist (30 mg kg⁻¹) had no effect on the heat hyperalgesia or pain-related behaviour ratings where 0 is none and 5 is non weight bearing and complete avoidance of limb contact. Pretreatment with a NK₂ receptor antagonist (10 mg kg⁻¹) systemically prevented the heat hyperalgesia and pain-related behaviour ratings from developing in the early stages of the inflammation. The inactive stereoisomers of NK₁ receptor antagonist, CP100,263, or the NK₂ receptor antagonist, SR48965, administered at the same doses, had no effect on the joint inflammation or the heat hyperalgesia.
5. Post-treatment systemically with either the NK₁ (0.130 mg kg⁻¹) or the NK₂ (0.110 mg kg⁻¹) receptor antagonist resulted in a dose-dependent reversal of the heat hyperalgesia. Pain-related behaviour ratings were reduced by post-treatment only with the NK₁ receptor antagonist. The inactive stereoisomers of the NK₁ receptor antagonist, CP100,263, or the NK₂ receptor antagonist, SR48965, administered at the same doses, had no effect on the behavioural responses.
6. Direct pretreatment of the knee joint with either the NK₁ (30 mg) or the NK₂ (10 mg) receptor antagonist prevented the heat hyperalgesia from developing without affecting joint swelling. The inactive stereoisomers of the NK₁ receptor antagonist, CP100,263, or the NK₂ receptor antagonist, SR48965, administered at the same doses, had no effect on the joint inflammation or the heat hyperalgesia.
7. There appears to be a differential role for the spinal tachykinin receptors in the development and maintenance of the heat hyperalgesia associated with acute joint inflammation. The NK₂ receptors appear to be activated early in the development of the heat hyperalgesia and NK₁ receptors are involved in the maintenance of the heat hyperalgesia.
8. Peripherally, both NK₁ and NK₂ receptors are involved in the development of heat hyperalgesia and pain-related behaviour ratings induced by acute inflammation.

     

Risk infection factors in the total hip replacement

Infection is a complication that occurs in a considerable percentage of hip prostheses replacements, being in many cases necessary to retire them, which generates important health and economical problems. Objectives: To know the distribution of infection and its risk factors in total hip replacement. Material and methods: A four year prospective study was developed in the rehabilitation and orthopedic center of La Paz Hospital. A total of 873 patients were included. Patients were controlled by means of active epidemiological surveillance until the day of discharge, listing up their characteristics at admission and risk factors during their stay. A multivariant study was carried out to determine risk factors. Results: Patients, average age was 63 years, 3.4% of them suffered from diabetes and there were no inmunocompromised patients. The percentage of wound infection during the four years was 6%, being reduced to 1.2% in the last year. The risk factors found in the multivariant study were: incorrect prophylaxis (OR: 3.85), wrong scaring (OR: 14.06), suffering more than one intervention (OR: 7.31) and a hospitalization period longer than 30 days (OR: 2.84). Conclusion: We think that special attention in the care of the surgical wound, as well as the correct use of prophylaxis, can significantly collaborate to the reduction of infection.     

Evolution of renal replacement therapy in East Germany from 1989 to 1992

Diminished availability of facilities for renal replacementtherapy is known to cause spuriously low acceptance and treatmentrates. In this context the evolution of renal replacement therapyin the former German Democratic Republic is a useful model tostudy and to quantify some of the relevant factors. We performed a survey in all dialysis units for adults in EastGermany (excluding East Berlin) by questionnaire, achievinga response rate of 97%. From December 1989 to December 1992the number of dialysis centres increased from 53 to 96 (+81%),reaching 6.7 centres p.m.p. Of these facilities, 45% were hospitalunits, 29% private units, and 26% dialysis units run by non-profithealth care organizations. The number of dialysis stations forregular dialysis treatment increased from 602 to 1276 (+112%),i.e. 89 stations p.m.p. In parallel, the number of chronic dialysispatients increased from 2127 to 3848 (+81%), i.e. 267 patientsp.m.p. A more detailed survey was carried out in Thüringen andpart of Sachsen, in a region covering 5 million inhabitants.The acceptance rate for chronic dialysis treatment has increasedfrom 49 to 107 patients p.m.p. (+115%). The average age of newpatients increased from 49 to 59 years, the proportion of patientsaged 65 years increased from 16 to 42% and the proportion ofdiabetics from 13 to 35%. Introduction of alternative treatmentmodalities became possible, with 2.3% of the patients receivinghaemofiltrations and 3% CAPD. The proportion of HBs-antigen-positivepatients decreased from 14.2% to 5%. At the end of 1989 in the former GDR (excluding East Berlin),773 patients and, at the end of 1992, 1153 patients were alivewith functioning renal transplants (+49%). The annual rate oftransplantations was 254 in 1989, and 283 in 1992 (+11%), i.e.18 transplantations p.m.p. (including East Berlin). At the end of 1989 2900 patients (193 p.m.p.), and at the endof 1992 5001 patients (347 p.m.p.), werealive on renal replacementtherapy (dialysis or functioning renal transplant) in East Germany,excluding East Berlin; this represents a 72% increase. The figures in East Germany are now almost equivalent to thosein West Germany regarding the number of admissions (incidence),whereas the number of patients on renal replacement therapyis still lower (prevalence).     

Early one-stage orthotopic jejunal pedicle-graft interposition in long-gap esophageal atresia

Since 1988, four children with long-gap esophageal atresia have undergone one-stage orthotopic jejunal pedicle-graft interposition at the age of 2 to 3 months. Obtaining enough jejunal length was no problem and major early complications did not occur. In one patient stenosis of the distal anastomosis was problematic and required corrective surgery. None of the patients demonstrated jejunitis as a result of gastroesophageal reflux. With follow-up periods of 12, 27, 46, and 60 months, all patients are doing well. It is concluded that the jejunum is a better esophageal substitute than is generally appreciated.