[Reliable fixation of cochlear implant electrode mountings in children and adults--initial experiences with a new titanium clip]

BACKGROUND

There is a reported 1% incidence of delayed migration of extrusions of the electrode arrays out of the cochlea.

METHODS

A titanium clip to fix the electrode array of the MED EL Combi 40 Cochlear Implant System is described. The clip is designed and shaped in a double U configuration. The clip material allows easy adaption to the individual anatomical situation. The clip is fixed to a bony bridge at the incus bar and fixes the electrode in a plane parallel to the chorda facial angle. It is closed around the electrode similarly to a stapes piston around the incus. Additional tests which examined the possible risk of damaging the electrode carrier and clinical findings are described.

RESULTS

The clip was used in 23 cases with a follow-up period up to 1 year. No signs for dislocation of the electrode were found. In one revision case the clip was covered with a thin mucosal layer. The electrode array showed no signs of damage. Intraoperative findings confirmed the experimental tests on the electrode fixation.

CONCLUSION

The titanium clip facilitates safe and quick fixation of the electrode array and prevents dislocation. its flexibility and shape minimizes the risk of damage.

Severe testotoxicosis phenotype associated with Asp578-->Tyr mutation of the lutrophin/choriogonadotrophin receptor gene

Testotoxicosis is a form of male precocious puberty caused by heterogeneous activating mutations in the gene for the lutrophin/choriogonadotrophin receptor (LHR). A patient with an unusually early and severe presentation of testotoxicosis, including profound Leydig cell hyperplasia, was found to have a sporadic mutation encoding Asp578-->Tyr. The severe testotoxicosis phenotype appears to be related to the strongly activating nature of the Tyr substitution.

Prognostic significance of molecular alterations in human pancreatic carcinoma--an immunohistological study

BACKGROUND

During the last decade, many molecular alterations have been described for pancreatic carcinomas. However, the clinical and prognostic value of these alterations has been discussed and is controversial.

METHODS

An immunohistochemical study was performed in 82 cases of adenocarcinoma of the pancreas. Using specific antibodies, expression of EGF, EGF-receptor, cERB-B2, p53, p21CIP1, cyclin-D1, BCL-2, CD95 and KI67 was evaluated.

RESULTS

Overexpression of the different molecules was found in 44-69% of the pancreatic carcinomas. With regard to clinico-pathological features, p53 positivity was more frequently found in advanced and undifferentiated tumours (P<0.05), EGF overexpression was significantly more frequent in advanced tumours (P<0.05) and CD95 overexpression was observed to a greater extent in undifferentiated tumours (P<0.05). Besides cyclin-D1, none of the molecules tested was of prognostic significance. Patients whose tumours expressed cyclin-DI lived significantly shorter than patients with cyclin-D1-negative tumours. However, in subgroup analyses of patients with the same tumour stage or tumour grade, even cyclin-D1. expression had no prognostic significance.

CONCLUSION

These results demonstrate that the prognostic significance of the molecules tested here is low. Nevertheless, with regard to tumorigenesis and tumour biology of pancreatic carcinoma, determination of molecular alterations could provide important information about pancreatic cancer.

Autoimmune thyrotoxicosis developed during growth hormone (GH) treatment of an adult with childhood onset GH-deficiency. A causal relationship?

Thyroid hyperfunction during growth hormone (GH) therapy has not been reported previously. We report a case of a 33-year-old female who developed autoimmune thyrotoxicosis during treatment with GH and with normalization of the thyroid function after discontinuation of GH therapy. After rechallenge with GH she again developed thyrotoxicosis, this time with presence of thyroid autoantibodies and without normalization of the thyroid function after stopping the GH treatment. Several possibilities for a causal relationship between GH therapy and development of autoimmune thyrotoxicosis are proposed.

Trehalose-6-phosphate phosphatases from Arabidopsis thaliana: identification by functional complementation of the yeast tps2 mutant

It is currently thought that most flowering plants lack the capacity to synthesize trehalose, a common disaccharide of bacteria, fungi and invertebrates that appears to play a major role in desiccation tolerance. Attempts have therefore been made to render plants more drought-resistant by the expression of microbial genes for trehalose synthesis. It is demonstrated here that Arabidopsis thaliana itself possesses genes for at least one of the enzymes required for trehalose synthesis, trehalose-6-phosphate phosphatase. The yeast tps2 mutant, which lacks this enzyme, is heat-sensitive, and Arabidopsis cDNA able to complement this effect has been screened for. Half of the yeast transformants that grew at 38.6 degrees C were also able to produce trehalose. All of these expressed one of two Arabidopsis cDNA, either AtTPPA or AtTPPB, which are both homologous to the C-terminal part of the yeast TPS2 gene and other microbial trehalose-6-phosphate phosphatases. Yeast tps2 mutants expressing AtTPPA or AtTPPB contained trehalose-6-phosphate phosphatase activity that could be measured both in vivo and in vitro. The enzyme dephosphorylated trehalose-6-phosphate but not glucose-6-phosphate or sucrose-6-phosphate. Both genes are expressed in flowers and young developing tissue of Arabidopsis. The finding of these novel Arabidopsis genes for trehalose-6-phosphate phosphatase strongly indicates that a pathway for trehalose biosynthesis exists in plants.

Growth hormone treatment of short children born small-for-gestational-age: the Nordic Multicentre Trial

The aims of this study were to evaluate the efficacy and safety of different doses of growth hormone (GH) treatment in prepubertal short children born small-for-gestational-age (SGA). Forty-eight children born SGA from Sweden, Finland, Denmark and Norway were randomly allocated to three groups: a control group of 12 children received no treatment for 2 y, one group was treated with GH at 0.1 IU/kg/d (n=16), and one group was treated with GH at 0.2 IU/kg/d (n=20). In total 42 children completed 2 y of follow-up, and 24 children from the treated groups completed 3 y of treatment. Their mean (SD) age at the start of the study was 4.69 (1.61) y and their mean (SD) height was -3.16 (0.70) standard deviation scores (SDS). The children remained prepubertal during the course of the study. No catch-up growth was observed in the untreated group, but a clear dose-dependent growth response was found in the treated children. After the third year of treatment, the group receiving the higher dose of GH, achieved their target height. The major determinants of the growth response were the dose of GH used, the age at the start of treatment (the younger the child, the better the growth response) and the family-corrected individual height deficit (the higher the deficit, the better the growth response). Concentration of insulin-like growth factor-I (IGF-I) and IGF-binding protein-3 increased during treatment. An increase in insulin levels was found without negative effects on fasting glucose levels or glycosylated haemoglobin levels. GH treatment was well tolerated. In conclusion, short prepubertal children born SGA show a dose-dependent growth response to GH therapy, and their target height SDS can be achieved within 3 y of treatment given GH at 0.2 IU/kg/d. However, the long-term benefit of different regimens of GH treatment in children born SGA remains to be established.

[Schizophrenia-like symptoms in the Westphal-Strümpell variation of Wilson disease]

Wilson's disease is a rare, autosomal recessive disorder of copper metabolism due to low serum ceruloplasm, resulting in increased copper deposition, especially in the liver and basal ganglia in the brain. The pseudosclerotic type of Wilson's disease, also known as the Westphal-Strümpell form, is distinguished by positional tremor, ataxia and dysarthria as the main symptoms. We use the example of a 23-year-old patient whose neurological symptoms were preceded by a long history of a schizophrenic-like disorder. Clinical symptoms are presented. MRI, SPECT and PET images are illustrated. Therapy and outcome are discussed.

Effects of preinduction and intraoperative warming during major laparotomy

We have investigated the influence of active warming before and during operation on blood loss, transfusion requirements, duration of stay in the post-anaesthesia care unit (PACU) and perioperative costs in 40 patients undergoing major abdominal surgery. Patients were allocated randomly to one of two groups: in the study group (n = 20), patients were actively warmed using forced air for 30 min before induction of general anaesthesia and during anaesthesia. Passive protection against heat loss consisted of circulating water mattresses, blankets and fluid warming devices, and was used both in the active warming group and in the control group (n = 20). At the end of surgery the change in core temperature was significantly less in the group of actively warmed patients (0.5 (SD 0.8) degree C vs 1.5 (0.8) degree C; P < or = 0.01). Blood loss and transfusion requirements were less in the actively warmed patients, who had a shorter duration of stay in the PACU (94 (SD 42) min vs 217 (169) min; P < or = 0.01) and a 24% reduction in total anaesthetic costs.

[Postoperative results of stapes revision]

BACKGROUND

In this retrospective study indications, intraoperative findings, reconstruction techniques and postoperative hearing results in revision stapes surgery were evaluated.

PATIENTS

Between March 1988 and January 1996, 150 patients underwent stapes revision. Indications for surgery were the presence of conductive hearing loss (132), dizziness (12), sensorineural hearing loss (3), deafness (2), and tinnitus (1).

RESULTS

Intraoperative findings were lateral migration of the implant, regrowth of bone in the oval window niche, erosion of incus, cholesteatoma, and others. In most cases a new prosthesis (gold piston) was inserted between incus and vestibulum. In cases with incus erosion, a malleovestibulopexy was performed. Seventy-three percent of patients who underwent revision stapes surgery because of conductive hearing loss showed a hearing improvement of 20 dB or more. All patients who underwent revision stapes surgery because of dizziness reported an improvement of their symptoms postoperatively.

CONCLUSIONS

Revision stapes surgery should be approached by experienced surgeons, because the risk of severe sensorineural hearing loss is higher than at the time of primary stapedectomy. Informed consent is mandatory.

Humoral rejection after heart transplantation: reliability of intramyocardial electrogram recordings (IMEG) and myocardial biopsy

In recent years, as the importance of humoral-mediated rejection has increasingly become recognized, the fact that endomyocardial biopsies (BX) evaluated according to the criteria of the International Society for Heart and Lung Transplantation often produce false-negative results has become a matter of concern. To evaluate the reliability of measuring intramyocardial ECG amplitude (IMEG) and immunofluorescence evaluation (FITC-labeled anti-IgG/ IgM staining) of endomyocardial biopsies (IFM), heterotopic neck-heart transplantation (HTX) was performed on eight beagles previously sensitized through skin transplantations. After HTX, IMEG, echo, and donor-specific antibodies in serum (IgG, IgM) were determined daily and myocardial biopsies (IFM, BX) were performed once every 2 days. Accelerated (humoral) rejection occurred on the 5th (4th-5th) postoperative day and sensitivity of IMEG, IFM, and BX was 100%, 75%, and 12.5%, respectively. In each case rejection was recognized so early that it was possible to initiate therapy with "restitutio ad integrum". Our results show that, as opposed to endomyocardial biopsy (IFM, BX), IMEG diagnosis detected humoral-mediated rejection early and with high reliability.

Growth hormone treatment of children with Prader-Willi syndrome affects linear growth and body composition favourably

We have compared the growth and the body composition in children with Prader-Willi syndrome (PWS) with and without growth hormone treatment (recombinant GH 0.1 IU/kg/day) after a 1-y period. Twenty-nine prepubertal children with PWS, with mean body mass index (BMI) SDS of 2.2, and 10 (control) healthy obese children with mean BMI SDS of 5.6, underwent 24-h frequent blood sampling. Both PWS and control obese children had low and similar GH levels (0.7 microg/l +/- 0.4SD). Serum IGF-I levels, however, were significantly lower in children with PWS (-1.5SDS +/- 0.8SD vs -0.2SDS +/- 0.8SD). The 29 PWS children were randomized into 2 groups of 15 and 14 subjects for GH treatment and no treatment, respectively. Height velocity increased from -1.9SDS to + 6.0SDS in the treated group (p < 0.001) and decreased from -0.1SDS to -1.4SDS in the control PWS group during the study year. BMI decreased significantly for the treated group (+3.0SDS to +2.0SDS). Relative fat mass decreased significantly, while fat-free mass increased (p < 0.001) for the treated group. No significant changes were noticed in body composition in the control PWS group. In conclusion, the low spontaneous 24-h GH secretion, regardless of body weight, and the exceptional response to growth hormone treatment together with the finding of low IGF-I levels suggest that growth hormone deficiency is a common feature of PWS, as a result of hypothalamic dysfunction. Treatment with growth hormone is beneficial for the majority of PWS children.

[Witch ointments and aphrodisiacs. A contribution to the cultural history of nightshade plants]

The nightshades (solanaceae) were used as intoxicants since the ancient civilisations and are still in use today. Their alkaloids, atropine and scopolamine, were the major active substances of the ointments of witches, of medieval "anaesthetics", and of modern poisons for murder. In a medium dose-range the predominant symptoms are hallucinations and illusions. This explains the use of nightshades in fortune-telling and religious rituals. In higher doses the alkaloids produce coma and apnea. Scopolamine enjoyed a particular popularity as a poison for murder. In the 19th century the nightshade alkaloids were also in clinical use. This article focusses on the medical history of the psychosis due to intoxication with solanaceae.

Developmental arrest of germ cells in the pathogenesis of germ cell neoplasia

Clinical observations and epidemiological evidence suggest that important aetiopathological events that cause neoplastic transformation of the male germ cell may occur in fetal life or early infancy. The incidence of germ cell neoplasia is high in individuals with various disorders of gonadal development and sexual differentiation, such as gonadal dysgenesis or androgen insensitivity syndrome. Increased risk has also been noted in individuals with trisomy 21, idiopathic infertility and low birth weight. Infertility is sometimes associated with small aberrations of sex chromosomes (e.g. low frequency mosaicism XY/XO) which can also be found in patients with testicular cancer. The variety of conditions that predispose to testicular neoplasia and the rise in its incidence in many countries speaks for the influence of environmental factors which may affect genetically predisposed individuals. We hypothesise that if the development of the testis is disturbed or delayed, primordial germ cells or gonocytes undergo maturation delay or differentiation arrest which may render them susceptible to neoplastic transformation. Morphologically homogenous premalignant carcinoma in situ (CIS) cells have the potential to differentiate into a variety of histological forms of overt testicular tumours. Analysis of cell surface antigens expressed by CIS cells found in the vicinity of pure and mixed tumours demonstrates that CIS cells are phenotypically heterogeneous. Comparison of the phenotypes of CIS cells, primordial germ cells, human embryonal carcinoma cells and closely related primate embryonal stem cells reveals various similarities but also differences. We speculate that phenotypical heterogeneity of CIS cells may be associated with their potential to give rise to different tumour types, and may be related to the developmental stage of the early germ cell which has undergone malignant transformation.

Germ cell cancer and disorders of spermatogenesis: an environmental connection?

Why is there a small peak of germ cell tumours in the postnatal period and a major peak in young age, starting at puberty? And, paradoxically, small risk in old age, although spermatogenesis is a lifelong process? Why is this type of cancer more common in individuals with maldeveloped gonads, including undescended testis, gonadal dysgenesis and androgen insensitivity syndrome? Why has there, during the past 50 years, been a quite dramatic increase in testicular cancer in many developed countries? These are just a few of many questions concerning testicular cancer. However, the recent progress in research in the early stages of testicular cancer (carcinoma in situ testis (CIS)) allows us to begin to answer some of these questions. There is more and more evidence that the CIS cell is a gonocyte with stem cell potential, which explains why an adult man can develop a non-seminoma, which is a neoplastic caricature of embryonic growth. We consider the possibility that CIS cells may loose their stem cell potential with ageing. Along these lines, a seminoma is regarded a gonocytoma where the single gonocytes have little or no stem cell potential. The Sertoli and Leydig cells, which are activated postnatally and during and after puberty, may play a crucial role for both the development of the CIS gonocyte and progression of the neoplasm to invasiveness. The reported increase in testicular cancer is not the only sign that male reproductive health is at risk. There are reports that undescended testis and hypospadias have become more common. Also semen quality has deteriorated, at least in some countries. The epidemiological evidence suggests that environmental factors may play a role. Are the environmental hormone disrupters (e.g. DDT, PCB, nonylphenol, bisphenol A) to be blamed for the apparently synchronised deterioration in these aspects of male reproductive health?

Central precocious puberty in girls: internal genitalia before, during, and after treatment with long-acting gonadotropin-releasing hormone analogues

Pelvic ultrasonography was systematically performed on 33 girls with idiopathic central precocious puberty to investigate the impact of treatment with gonadotropin-releasing hormone analogues on female internal genitalia. All girls were treated with a long-acting gonadotropin-releasing hormone analogue (Decapeptyl Depot; Ferring Co., Copenhagen, Denmark) 75 micrograms/kg every 4 weeks. Before, during, and after treatment, pelvic ultrasonography was performed and ovarian and uterine volumes were calculated. The size of follicles > 5 mm were accurately measured. The results were related to a normative study of healthy Danish schoolgirls. Our data demonstrated that ovaries and uterus are enlarged in a significant number of girls (50%) with the diagnosis of central precocious puberty at the time of diagnosis. Median ovarian volume at time of diagnosis was 1.1 standard deviation scores (range -0.6 to 3.2 SD), median uterine volume was 1.8 standard deviation scores (range 0.0 to 3.5 SD). Within 3 months of treatment, both ovarian and uterine volumes decreased significantly (p < 0.01) to normal values appropriate for age. Median ovarian volume after 3 months of treatment was 0.0 SD (range -2.4 to 1.5 SD); median uterine volume was 0.7 SD (range -0.6 to 4.1 SD). Ovarian and uterine volume remained within normal range (< 2 standard deviation scores) after discontinuation of treatment. Follicles and macrocysts regressed during treatment. None of the girls' ovaries had a polycystic appearance during or after treatment with the gonadotropin-releasing hormone analogue. Our results confirmed pelvic ultrasonography as a reliable tool for investigation of internal genitalia in girls with precocious puberty and as a valid method for evaluation of the efficacy of treatment with gonadotropin-releasing hormone analogues. We suggest that repeated investigations be performed when evaluating treatment because the morphologic changes, including follicular maturation or regression, reflect ovarian stimulation or suppression. We found no evidence that girls with precocious puberty treated with long-acting gonadotropin-releasing hormone analogues have enlarged polycystic ovaries develop.

[Prognostic value of molecular biologogy and immunologic parameters in human pancreatic carcinoma]

In the present study we investigated the prognostic relevance of molecular and immunological changes in pancreatic carcinoma. 82 tissue specimens of adenocarcinoma of the pancreas were stained immunohistochemically with following factors: p53, p21WAF1, Cyklin D, EGF, EGF-R, cERB-B2, CD95, BCL-2 and Cathepsin D. We further determined the serum levels of sCD44, sCD44v6, neopterin and IL-2R. Except Cyclin D none of the immunohistochemically determined factors had prognostic significance. Interestingly all of the immunological serum parameters were of high prognostic significance. These data demonstrate the prognostic relevance of immunological parameters in human adenocarcinoma of the pancreas and could raise the possibility of an early immunological intervention in pancreatic cancer.

X-ray structure of motor and neck domains from rat brain kinesin

We have determined the X-ray structure of rat kinesin head and neck domains. The folding of the core motor domain resembles that of human kinesin reported recently [Kull, F. J., et al. (1996) Nature 380, 550-554]. Novel features of the structure include the N-terminal region, folded as a beta-strand, and the C-terminal transition from the motor to the rod domain, folded as two beta-strands plus an alpha-helix. This helix is the beginning of kinesin's neck responsible for dimerization of the motor complex and for force transduction. Although the folding of the motor domain core is similar to that of a domain of myosin (an actin-dependent motor), the position and angle of kinesin's neck are very different from those of myosin's stalk, suggesting that the two motors have different mechanisms of force transduction. The N- and C-terminal ends of the core motor, thought to be responsible for the directionality of the motors [Case, R. B., et al. (1997) Cell 90, 959-966], take the form of beta-strands attached to the central beta-sheet of the structure.

Serum inhibin B in healthy pubertal and adolescent boys: relation to age, stage of puberty, and follicle-stimulating hormone, luteinizing hormone, testosterone, and estradiol levels

Inhibin B levels were measured in serum from 400 healthy Danish prepubertal, pubertal, and adolescent males, aged 6-20 yr, in a cross-sectional study using a recently developed immunoassay that is specific for inhibin B, the physiologically important inhibin form in men. In addition, serum levels of FSH, LH, testosterone, and estradiol levels were measured. Serum levels of inhibin B, FSH, LH, testosterone, and estradiol all increased significantly between stages I and II of puberty. From stage II of puberty the inhibin B level was relatively constant, whereas the FSH level continued to increase between stages II and III. From stage III of puberty the FSH level was also relatively constant, although there was a nonsignificant trend of slightly decreased FSH levels at pubertal stage V compared to stage IV. The levels of serum LH, testosterone, and estradiol increased progressively throughout puberty. In prepubertal boys younger than 9 yr, there were no correlation between inhibin B and the other three hormones. In prepubertal boys older than 9 yr, a significant positive correlation was observed between inhibin B and FSH, LH, and testosterone. However, at this pubertal stage, each hormone correlated strongly with age, and when the effect of age was taken into account, only the partial correlation between inhibin B and LH/testosterone remained statistically significant. At stage II of puberty, the positive partial correlation between inhibin B and LH/testosterone was still present. At stage III of puberty, an negative partial correlation between inhibin B and FSH, LH, and estradiol was present, whereas no correlation between inhibin B and testosterone could be observed from stage III onward. The negative correlation between inhibin B and FSH persisted from stage III of puberty onward, whereas the correlation between inhibin B and LH and between inhibin B and estradiol was nonsignificant at stages IV and V of puberty. In conclusion, in boys, serum inhibin B levels increase early in puberty; by pubertal stage II the adult level of inhibin B has been reached. The correlation of inhibin B to FSH, LH, and testosterone changes during pubertal development. Early puberty is characterized by a positive correlation between inhibin B and LH/testosterone, but no correlation to FSH. Late puberty (from stage III) is characterized by a negative correlation between inhibin B and FSH (which is maintained in adult men), a diminishing negative correlation between inhibin B and LH, and no correlation between inhibin B and testosterone, suggesting that developmental and maturational processes in the hypothalamic-pituitary-gonadal axis take place, leading to the establishment of the closed loop feedback regulation system operating in adult men. The positive correlation between inhibin B and LH/ testosterone at the time when serum inhibin B levels rise early in puberty suggests that Leydig cell factors may play an important role in the maturation and stimulation of Sertoli cells in the beginning of pubertal development.

Control system modification of an electromechanical pulsatile total artificial heart

A reliable control system is one of the most important characteristics of the electromechanical pulsatile total artificial heart (TAH). Obtaining an error-free procedure is essential for a successful in vivo implantation. To avoid any malfunction of the electrical control system, a modification of the previously designed controller was made to ensure stable pumping without the Hall effect sensor missensing. The installation position of the Hall effect sensor was changed from the top of the housing to the central piece with small magnets being installed in the stabilizer rods. The usage of the Hall effect sensor was chosen as an electrical switch. An in vitro one month running test of the TAH demonstrated adequate hydrodynamic performance with a completely error-free pumping characteristic. The total efficiency of the TAH was 12.6 +/- 1.4% at an 8 L/min outflow and 10.7 +/- 1.0% at a 6 L/min outflow condition.