ABSTRACT
In vitro porcine arteries and veins have been welded end-to-end using either a 808 nm diode laser combined with an indocyanine green enhanced albumin solder, or with a continuous-wave (cw) Ho:YAG laser without biological solder. The vascular stumps were approached to each other over a coronary dilatation catheter in order to obtain a precise alignment and good coaptation. Standard histology revealed for both welding techniques lateral tissue damage between 2 and 3 mm caused by laser-induced heat. Good solder attachment to the tissue was observed by the use of a scanning electron microscope. The vessels soldered with the 808 nm diode laser using albumin solder showed considerably higher tensile strength (1 N compared to 0.3 N) than vessels welded exclusively by Ho:YAG laser radiation. In contrast, leaking pressure (350 +/- 200 mmHg) and bursting pressure (457 +/- 200 mmHg) were found to be independent of the welding technique used. This study demonstrates that fast (total welding time about 2-5 min), stable and tight microvascular anastomosis can be achieved with the use of a dye-enhanced albumin laser soldering technique and an ancillary coronary dilatation catheter.
Subject(s)
Anastomosis, Surgical/methods , Laser Coagulation/instrumentation , Saphenous Vein/surgery , Tibial Arteries/surgery , Animals , Serum Albumin, Bovine/therapeutic use , SwineABSTRACT
BACKGROUND AND OBJECTIVE: The surgical treatment of full-thickness cartilage defects in the knee joint remains a therapeutic challenge. Recently, new techniques for articular cartilage transplantation, such as mosaicplasty, have become available for cartilage repair. The long-term success of these techniques, however, depends not only on the chondrocyte viability but also on a lateral integration of the implant. The goal of this study was to evaluate the feasibility of cartilage welding by using albumin solder that was dye-enhanced to allow coagulation with 808-nm laser diode irradiation. STUDY DESIGN/MATERIALS AND METHODS: Conventional histology of light microscopy was compared with a viability staining to precisely determine the extent of thermal damage after laser welding. Indocyanine green (ICG) enhanced albumin solder (25% albumin, 0.5% HA, 0.1% ICG) was used for articular cartilage welding. For coagulation, the solder was irradiated through the cartilage implant by 808-nm laser light and the tensile strength of the weld was measured. RESULTS: Viability staining revealed a thermal damage of typically 500 m in depth at an irradiance of approximately 10 W/cm(2) for 8 seconds, whereas conventional histologies showed only half of the extent found by the viability test. Heat-bath investigations revealed a threshold temperature of minimum 54 degrees C for thermal damage of chondrocytes. Efficient cartilage bonding was obtained by using bovine albumin solder as adhesive. Maximum tensile strength of more than 10 N/cm(2) was achieved. CONCLUSIONS: Viability tests revealed that the thermal damage is much greater (up to twice) than expected after light microscopic characterization. This study shows the feasibility to strongly laser weld cartilage on cartilage by use of a dye-enhanced albumin solder. Possibilities to reduce the range of damage are suggested.
Subject(s)
Cartilage, Articular/surgery , Chondrocytes/physiology , Laser Therapy/methods , Animals , Cattle , Cell Survival , Chondrocytes/radiation effects , Feasibility Studies , Indocyanine Green/pharmacology , Tensile StrengthABSTRACT
BACKGROUND: The application of lasers in orthopaedic surgery is increasing. However, some investigators have reported that osteonecrosis may occur after laser meniscectomy. The objective of the present study was to evaluate the effect of laser wavelength and energy on cartilage injury in an ex vivo model. METHODS: Fresh bovine articular cartilage was exposed to either holmium:yttrium-aluminum-garnet (Ho:YAG) or erbium:YAG-laser (Er:YAG) irradiation. Both lasers were operated in a free-running mode and at a pulse-repetition rate of 8 Hz. The effect of laser treatment at several energy levels (Er:YAG at 100 and 150 mJ and Ho:YAG at 500 and 800 mJ) was examined. For each light source and energy level, ten cartilage samples were assessed by conventional histological analysis and by confocal microscopy. Thermal damage was assessed by determining cell viability. RESULTS: The extent of thermal damage demonstrated by confocal microscopy was much greater than that demonstrated by histological analysis. The extent of thermal injury after Ho:YAG-laser irradiation was much greater than that after Er:YAG-laser irradiation, which was associated with almost no damage. In addition, the ablation depth was greater after treatment with the Er:YAG laser than after treatment with the Ho:YAG laser. CONCLUSIONS: In the present study, histological analysis underestimated thermal damage after laser irradiation. In addition, our findings highlighted problems associated with use of high-power settings of Ho:YAG lasers during arthroscopic surgery.
Subject(s)
Cartilage, Articular/injuries , Lasers/adverse effects , Animals , Cattle , Knee Joint , Microscopy, ConfocalABSTRACT
Sibling sex ratio (the ratio of brothers to sisters) was calculated for 444 boys with gender identity disorder (or with behaviors consistent with this diagnosis). The probands were ascertained from several researchers with expertise with this disorder and from the English language case report literature between 1938 and 1995. Among the probands with at least one sibling (N = 333), the results showed that boys with gender identity disorder had a significant excess of brothers to sisters, 131.1:100, when compared with the expected secondary sex ratio of 106:100. The excess of brothers replicated a previous study by Blanchard, Zucker, Bradley, and Hume (1995), in which the sibling sex ratio was 140.6:100. Further analyses showed that the probands were born later relative to their brothers than they were relative to their sisters. These findings are amenable to several psychosocial and biological explanations, which require further investigation.
Subject(s)
Gender Identity , Psychosexual Development , Sex Ratio , Sexual Dysfunctions, Psychological/genetics , Sibling Relations , Child , Child, Preschool , Family Characteristics , Humans , MaleABSTRACT
In the course of a long-term study of 55 boys with early effeminate (cross-gender) behavior an effort was also made to ascertain the presence of sexual deviance in their parents, siblings, uncles, and aunts. For most of these groups of relatives, only one to three members in each group were found to be homosexual, equaling 4% male and 1% female for the total test population. Compared to similar studies, the results were not too different except in the case of the siblings of one study where the incidence was much higher. Some evidence is considered for the speculation of a nongenetic, congenital cause of homosexuality.
Subject(s)
Gender Identity , Homosexuality/psychology , Identification, Psychological , Adolescent , Child , Family , Follow-Up Studies , Humans , Male , Sex FactorsABSTRACT
This report continues the study of early effeminate behavior in boys. A previous article reported on the long term follow-up of 55 boys and the resulting outcome in homosexuality. In this paper an effort is made to explore further the nature of the connection between childhood effeminate behavior and adult homosexuality. Individual signs are discussed with regard to relevant aspects of their development. It is concluded that early effeminate behavior is not merely a forerunner of homosexuality in that it forecasts homosexuality, but that is is in fact the earliest stage of homosexuality itself.
Subject(s)
Gender Identity , Homosexuality , Identification, Psychological , Psychosexual Development , Adolescent , Adult , Child , Child, Preschool , Follow-Up Studies , Humans , Male , Social Adjustment , Transvestism/psychologySubject(s)
Homosexuality , Adolescent , Adult , Child , Child, Preschool , Gender Identity , Humans , Retrospective StudiesABSTRACT
This is a long term follow-up of 55 boys with early effeminate behavior. It was possible to determine the outcome in sexual orientation in 38 of the boys, which included homosexuality or variants of it in 35 (63.6 per cent) of the total of 55 and heterosexuality in three (5.5 per cent). In 10 boys the outcome was uncertain, and seven were lost to follow-up. An analysis of the uncertain cases suggests that the overall outcome in terms of homosexuality may prove to have been higher than 63.6 per cent. These results agree with those of previous prospective and retrospective studies, which are reviewed. From both types of such studies, the prospective ones starting out with instances of early effeminate behavior and the retrospective with cases of established homosexuality, the conclusion is ventured that all male homosexuality begins with early effeminate behavior. This has implications for future research on homosexuality.
Subject(s)
Child Behavior , Gender Identity , Homosexuality , Identification, Psychological , Adolescent , Adult , Age Factors , Child , Child, Preschool , Clothing , Follow-Up Studies , Humans , Male , Play and Playthings , Prospective Studies , Retrospective Studies , Sex Factors , Sexual BehaviorABSTRACT
Homosexuality in the male is commonly held to be the product of a specific family constellation consisting of a dominant mother and an ineffectual or hostile father. Prospective studies however, on boys with early effeminate behaviour, the majority of whom subsequently become homosexual, show that their closeness to the mother and distance from the father spring from their own needs. The physician should feel free to relieve parents of guilt for this condition.
