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Biomedical subjects

G Sattler

Publications and source records attributed to G Sattler.

At least 19 recordsLinked to original sources

[Tumescent technique for local anesthesia. Use and prospectives of aa new anesthetic method].

The tumescent technique for local anesthesia (TLA) involves the infiltration of the subcutaneous fatty tissue with a large volume of a diluted local anesthetic. This large added volume increases the tension in the tissue, creating more favorable conditions for the action of the analgesic and for dermatological operative measures. Originally developed for use in the area of liposuction, TLA has since proved to have advantages over other forms of analgesia in numerous other dermatological indications. Overall, TLA is an effective and practical analgesic technique associated with comparatively few side effects that has been shown to be very useful in surgery of the skin.

Adipose Tissue

Tumescent liposuction in Germany: history and new trends and techniques.

Due to the developments and changes of tumescent solution, infiltration technique, and cannulas, we perform tumescent liposuction today using up to 6-8 l tumescent solution. Total aspirate measures up to 9 l, pure fat aspired up to 5 l. Tumescent liposuction of extended areas can still be done as an outpatient procedure. The condition of patients intra- and postoperatively as well as results has improved and the predictability of outcome is more certain.

Germany

Effect of chronic administration of mestranol, tamoxifen, and toremifene on hepatic ploidy in rats.

The nonsteroidal antiestrogen tamoxifen increases the incidence of rat liver cancer through a variety of mechanisms. To compare the effects of tamoxifen (TAM) and a structurally similar analog toremifene (TOR) on rat liver, we determined the ploidy distribution for hepatocytes isolated from rats treated for 18 months with these antiestrogens or the estrogenic compound mestranol (MS). Female Sprague-Dawley rats were subjected to a 70% partial hepatectomy and administered the solvent, trioctanoin, or diethylnitrosamine (10 mg DEN/kg). After a 2-week recovery from the surgery, the rats were administered a basal diet or one containing TAM (250 or 500 ppm), TOR (250, 500, or 750 ppm), or MS (0.2 ppm) for 18 months. Pathologic changes in the liver were examined in the 15-22 rats per treatment group at the 18-month time point. An increased incidence of hepatocellular carcinomas (HCC) was detected in the 500 ppm TAM group, but not with the other treatments that did not include DEN. Both TOR and TAM promoted formation of DEN-initiated HCCs. At sacrifice, four to five rats per group were perfused and the hepatocytes isolated and cultured. Karyotypic analysis was performed on colcemid-blocked cells after 2 days in culture. The hepatic ploidy distribution was characterized in Giemsa-stained metaphase spreads. These studies indicated that chronic treatment with TAM alone resulted in a shift from tetraploid to diploid, as was also observed for rats treated once with DEN. TOR and MS alone did not cause this change in hepatic ploidy at the doses examined. A shift toward an increased content of diploid hepatocytes occurred in all rats treated once with DEN followed by TAM, TOR, or MS. These results indicate that tamoxifen administration results in a shift toward growth of diploid hepatocytes, thus contributing to its carcinogenic action in the rat liver.

Animals

[Tumescence local anesthesia. Improvement of local anesthesia methods for surgical dermatology].

The tumescent technique of local anesthesia was developed by J. Klein ten years ago to facilitate liposuction surgery. Tumescent anesthesia not only became the standard technique for liposuction, but proved to be of great value for other surgical problems in dermatology. Meanwhile, several noncosmetic uses for tumescent anesthesia were pioneered by dermatologic surgeons. This first review of the tumescent technique in German literature will focus on its specific advantages and disadvantages when applied in different fields of dermatologic surgery. Our own experience will be discussed, as well as future developments.

Anesthesia, Local

Specific chromosomal changes in albumin simian virus 40 T antigen transgenic rat liver neoplasms.

Hepatocytes isolated from 3-month-old female rats bearing the albumin promoter/enhancer SV40 T antigen construct as a transgene demonstrated a 20% aneuploidy rate and a significant duplication of chromosome 1. Other chromosome changes were observed but were not statistically significant. At this time in the development of hepatic lesions, only a relatively small number of microscopic altered hepatic foci could be noted. By contrast, hepatocytes isolated from the age-matched nontransgenic controls demonstrated only 1% aneuploidy. One hundred % of the metaphase spreads isolated from hepatocellular neoplasms in transgenic rats were aneuploid. Although there were many random changes, 70% of the neoplastic cells demonstrated an amplification of all or portions of chromosome 1q. Only 2% of the neoplastic cells had both a trisomy and a duplication. The smallest region of chromosome 1 that was duplicated was that between bands q3.7 and q4.3. A loss of chromosome 3 was detected in 50% of the neoplasms, as well as a loss of chromosome 6 in 72% of the neoplastic cells. The carcinomas with the highest proliferation rate had also lost at least one copy of chromosome 15 in 70% of the cells. The loss of chromosomes 3, 6, and 15 indicates that these regions may harbor one or more tumor suppressor genes. The amplification of a specific region of chromosome 1 is thus the first karyotypic alteration that can be identified in hepatocytes from livers from which hepatic neoplasms will arise. This indicates that expression or repression of one or more genes in this region may confer a growth advantage to preneoplastic hepatocytes, facilitating their transit to the neoplastic state in the stage of progression. Changes in chromosomes 3, 6, and 15 that occur subsequent to duplication of the q3.7-q4.3 region of chromosome 1 are changes possibly reflecting alteration of tumor suppressor genes with further enhancement of neoplastic growth.

Animals

Karyotypic changes in a multistage model of chemical hepatocarcinogenesis in the rat.

Karyotypic analysis of the stages of rat hepatocarcinogenesis has been facilitated by the development of an initiation-promotion-progression (IPP) protocol that permits separation and characterization of morphologically normal and altered hepatocytes in each of these three stages. The expression of the membrane antigen gamma-glutamyl transpeptidase (GGT) during the promotion and progression stages of rat hepatocarcinogenesis permits the isolation, culture, analysis, and comparison of hepatocytes in the two stages, which express this marker of carcinogenesis. Female rats were administered 10 mg diethylnitrosamine/kg at 5 days of age. One group of initiated rats was maintained on dietary phenobarbital admixed into a laboratory chow diet at 0.05% for 9 months after weaning (promotion protocol). This initiation-promotion (IP) group was compared with one subjected to the complete IPP protocol. The IPP group was initiated with diethylnitrosamine, maintained on phenobarbital for 6 months after weaning, and then subjected to a 70% partial hepatectomy and administered 100 mg ethylnitrosourea/kg 24 h later. These rats on the IPP protocol were then maintained on phenobarbital for an additional 3 months prior to sacrifice. At sacrifice, single hepatocyte suspensions were obtained and separated into populations of cells expressing or not expressing GGT. These hepatocyte populations were cultured separately and subjected to standard cytogenetic analysis. At least five animals per treatment and 100 metaphase spreads of good morphology per animal were examined. Although GGT- cells from the IP protocol were 80% tetraploid and 20% diploid, the GGT+ hepatocytes were greater than 90% diploid. The GGT+ cells from this protocol had a low rate of random aneuploidy (4.0 +/- 1.3%) compared with corresponding cells from the IPP protocol, but a higher level of background aneuploidy compared with GGT- cells from the IP protocol. The GGT+ hepatocytes from animals on the IPP protocol had a 35% incidence of aneuploidy. In addition, the GGT+ population had a 28 +/- 5% incidence of chromosomal breakage and a 17 +/- 5% incidence of chromosomal rearrangements. The primary nonrandom chromosomal changes observed in cells from the IPP protocol included duplication of all or part (1q37-43) of chromosome 1 and the loss of chromosomes 3p and/or 6q. These studies indicate that rat hepatocytes in the stage of promotion are euploid, whereas those in the stage of progression exhibit considerable genetic instability. The presence of multiple copies of chromosome 1 or a duplication of a region of this chromosome indicates that alteration of gene dosage for one or more of the genes present in this region is critical to the neoplastic conversion of rat hepatocytes, whereas the loss of all of 3p and the last light band of 6q may indicate the presence of tumor suppressor genes. Thus, the IP and IPP protocols coupled with the ability to isolate GGT+ and GGT- hepatocytes permit the differential cytogenetic characterization of the stages of promotion and progression in rat hepatocarcinogenesis.

Animals

Induction of hepatic aneuploidy in vivo by tamoxifen, toremifene and idoxifene in female Sprague-Dawley rats.

Since tamoxifen is efficacious for the prevention of second primary breast neoplasms in humans and has a low reported incidence of acute side effects, several structurally related compounds have been developed for the treatment of breast cancer including toremifene and idoxifene. We have compared the karyotypic alterations that occur after a single per os administration of 35 mg/kg of tamoxifen, toremifene or idoxifene to female Sprague-Dawley rats. One day following treatment, the rats were sacrificed and the hepatocytes isolated and cultured. After 47 h in culture, colcemid was added for 3 h prior to harvest of the hepatocytes for karyotypic evaluation. At least 100 metaphase spreads were examined for each of five rats per treatment. Toremifene resulted in aneuploidy in 50 +/- 7% of the cells examined and idoxifene induced a 57 +/- 4% aneuploidy compared with the 85 +/- 7% level induced by tamoxifen. Since the level of aneuploidy in solvent-treated rats was 3 +/- 3 %, the induction of aneuploidy in at least 50% of the cells from rats treated with tamoxifen, toremifene or idoxifene was highly significant. Analysis of electron micrographs of cultures treated with these antiestrogens demonstrated a range of phenotypes including multipolar spindles in toremifene-treated rats and condensed chromosomes in the presence of an intact nuclear envelope in occasional idoxifene-treated rat hepatocytes. The exclusion of chromosomes from the spindle apparatus and the lagging of some chromosomes on the metaphase plate correlate with the high rate of induction of aneuploidy in the rat liver as determined by karyotypic analysis of hepatocytes from rats treated with these triphenylethylenes.

Aneuploidy

Determinants of HIV risk among men who have homosexual sex and inject drugs.

Men with histories of both homosexual contact and injecting drug use (IDU) are at increased risk of HIV infection over men who have only one such risk. Despite this, their special needs and circumstances have been neglected by AIDS prevention programmes. A survey of a wide spectrum of homosexual male IDUs was carried out in Melbourne and Sydney in 1993 to inform the development of specific policy and programmes for HIV prevention in these subcultures. Of 169 men, self-reported HIV prevalence was 27%. Decreasing compliance with safe sex guidelines (as measured by numbers of casual partners, participation in anal intercourse and use of condoms) was associated with HIV seropositivity, increased age, and increased participation in sex work; having a regular male partner was not protective against unsafe sexual behaviour, no matter the length of the relationship. A substantial proportion (15%) reported inconsistent condom use during anal sex with more than two partners in the preceding month: they were slightly more likely to be engaging in sex work, less 'stable' and more likely to be HIV infected. Sexual risk was not strongly associated with unsafe injecting, which was in general safe. Men who both have homosexual sex and inject drugs are groups at high risk of HIV, more from unsafe sex than from shared injecting equipment; men who believed themselves to be HIV infected were continuing to have sex in such a way that would allow transmission. These are clearly groups in need of priority targeted interventions.

Adolescent

[Endoscopic venous surgery in postphlebitic syndrome].

Endoscopy of the subfascial space of the lower medial calf is able to demonstrate the morphological changes of perforators in patients with postthrombotic syndrome. Inspection of the subfascial space allows the differentiation of competent and incompetent perforators and a following complete dissection of only incompetent perforators. By means of this method more information about the texture of the fascia cruris can be achieved.

Endoscopes

[Endoscopic perforant vein revision. Current status].

Blind dissection of incompetent perforators is common practice for vein surgeons. Since many years some of them have been trying to do this endoscopically by means of the proctoscope or other endoscopes used for different purposes. At present, however, several surgeons are developing special instruments for this type of endoscopy. Lately some of these surgeons came together to work up their experiences and to study the probable future of the method. It permits the diagnosis and at the same time the treatment of incompetent perforators. It allows the healthy ones to be spared. All this can be done from a small incision distant to the site of the perforators where the skin often presents with trophic changes. However, general or regional anesthesia as well as the bloodless limb technique are prerequisites. As any endoscopy also this one has its specific dangers and complications and therefore has to be learned and performed carefully.

Angioscopes

[Wound management with split skin flaps--donor sites. Covering with the moist gel Geliperm].

In 23 patients, donor sites of split-thickness skin grafts were treated with Geliperm Hydrogel, a swellable polyacrylamide agar. Healing duration, toleration, exudation and pain were all noted during the daily change of dressing. In 22 of the 23 cases, good healing was obtained after an average of 12.3 days. We feel that Geliperm is excellently suitable for covering the donor sites of split-thickness skin grafts.

Acrylamides

Semiautomatic method for histomorphometry.

A semiautomatic measurement system for histomorphometry is presented. The system is based on a steppermotor-driven scanning stage which the operator controls via a digitizer. Movement in the scanning stage is carried out with respect to stationary cross-wires in the ocular of the microscopy. The system is connected to a PC-AT computer which utilizes the x- and y-coordinates of these movements for the calculation of the morphometric measurements. In addition, the system is supplemented by software for storage and analysis of measurement data.

Diagnosis, Computer-Assisted

[Covering circular skin defects using 4 rhombic transposition flaps].

Based on Limberg's principles concerning the design of local flaps, S. B. Jugo developed a new technique for the closure of circular skin defects: The defect is divided into 4 quadrants; then 4 symmetrical rhombic flaps are raised from the surrounding skin, all pointing in the same direction of rotation. The sides of each flap correspond to the radius of the skin defect and form an angle of 68 degrees. Finally, the flaps are rotated into the defect and sutured to each other. This technique is especially useful with large lesions of the trunk.

Aged

[Anterior tooth curvatures, tooth size and arch form].

In this study a possible relation between the morphological outline of the palatal concavity of upper incisors and that of the corresponding arch form was analysed. Our results showed that these two parameters seem to be independent variables of the masticatory system.

Dental Arch

Mathematical outline-analysis of eminence and fossa of the TMJ of Cercopithecus aethiops (Cercopithecidae, primates, Mammalia).

The contours of the eminence and the fossa of the temporomandibular joint (TMJ) of Cercopithecus aethiops, a monkey species, are analyzed in sagittal-vertical sections. The functionally relevant contours can be approximated by catenates for both the eminence as the protrusive guidance and the fossa as the retrusive guidance. This study reveals the more general character of the contour formula y = a cosh(x/a) - a. This may be true because all these catenates are similar to one another and since they can be found in the guiding contours of the components of the stomatognatic system in man as well as in Cercopithecus aethiops.

Animals