[MRI evaluation of carpal tunnel morphology after carpal tunnel release by a retinaculum lengthening technique]

AIM

The benefits of maintaining the pulley function of the flexor retinaculum in carpal tunnel release by lengthening or reconstructing it have been described. Quantitative MR imaging was used to investigate the morphological changes after open carpal tunnel release by such a retinaculum lengthening technique.

METHOD

Ten patients had bilateral carpal tunnel MRI pre- and postoperatively. The MRI examinations were performed with a 1.5 Tesla imaging system and wrist coils. Carpal tunnel volume, carpal arch width, median nerve position and flexor tendon position in relation to the hamate-trapezial axis were recorded .

RESULTS

Like other methods of carpal tunnel release with complete division of the flexor retinaculum, the retinaculum lengthening technique showed a significant postoperative increase of carpal tunnel volume. Carpal arch width increased only slightly. There was a significant palmar displacement of the median nerve but not of the flexor tendons.

CONCLUSION

The findings support the hypothesis that maintenance of the pulley function of the retinaculum may lead to an early postoperative recovery of grip strength. In spite of some difficulties in application quantitative MR imaging may be a useful tool in evaluating the carpal tunnel morphology.

ZD9331 as Second- or Third-Line Therapy in Patients With Advanced Colorectal Cancer

This study investigated the efficacy and tolerability of ZD9331 as second- or third-line treatment for patients with advanced colorectal cancer (aCRC). One hundred patients were recruited to the study: 45 in group 1 (failed first-line 5-FU-based regimen) and 55 in group 2 (failed first-line 5-FU-based regimen and second-line irinotecan). Patients received ZD9331 as a 30-minute intravenous infusion on days 1 and 8 of a 3-week cycle, and treatment continued until disease progression (PD) or withdrawal. After a median of 4 cycles of treatment, there were no objective responses in group 1 (N = 37), 25 (67.6%) patients had a best overall response of stable disease (SD), and 12 (32.4%) had PD. After a median of 3 cycles of treatment, there were 2 (4.5%) partial responses in group 2 (N = 44), 21 (47.7%) patients had a best overall response of SD, 20 (45.4%) had PD, and 1 (2.3%) had clinical progression. At data cut-off, 59.5% and 77.3% of patients in groups 1 and 2, respectively, had PD. The main adverse events were neutropenia (69%), fatigue (53%), nausea (46%), and diarrhea (40%), and most (72.3%) were grade I/II. ZD9331 demonstrated minimal antitumor activity, and manageable toxicity, in the second- or third-line treatment of aCRC.

Priming with testosterone enhances stimulated growth hormone secretion in boys with delayed puberty

BACKGROUND AND OBJECTIVE

Tests for growth hormone (GH) deficiency are not always helpful in the differential diagnosis of physiological delay of growth and puberty and GH deficiency.

PATIENTS AND METHODS

To enhance diagnostic specificity, we used a single dose testosterone priming before repeating the arginine stimulation test in 26 boys with short stature and only early signs of puberty who failed to show an adequate response of serum GH in the first test.

RESULTS

77% (20/26 patients) increased their serum GH peak to more than 10 ng/ml, whereas six patients were still below this concentration.

CONCLUSION

We propose that testosterone priming is a useful tool to distinguish between physiological delay of growth and puberty and GH deficiency and should be included in the diagnostic procedure.

Medical students' perceptions of sexual health issues prior to a curriculum enhancement

The objectives were to compare first, second and third year medical students on self-perceived sexual health knowledge, comfort in addressing sexual health problems, and attitudes towards the importance of addressing sexual health issues with patients as part of a sexual health medical curriculum enhancement project. A paper-and-pencil questionnaire survey was designed and administered to first and second year medical students at the start of the fall semester, resulting in high participation rates for both years (98% and 86%, respectively). Third year students were surveyed through an on-line version of the questionnaire yielding a lower response rate (52%). Multivariate statistical analyses were used to compare knowledge, comfort and attitudes by year in medical school. Results were as follows: As might be expected, sexual health knowledge and comfort in addressing sexual health problems increased linearly from first to third year (P<0.01) for all questions. Unexpectedly, second year students had significantly higher scores on questions assessing attitudes towards the importance of addressing sexual health issues than either first or third year students (P<0.001). Female medical students reported that addressing sexual health issues with patients was significantly more important than did male medical students; however, male students reported higher levels of self-reported knowledge and comforting related to sexual health issues than did female students in a number of areas. In conclusion, knowledge gained from this survey was used to finalize the design of an enhanced, integrated curriculum on sexual health for medical students. Further investigation of gender differences related to training medical students in this area is suggested.

Short-term growth response to GH treatment and considerations upon the limits of short-term growth predictions

OBJECTIVES

To investigate the impact of short-term growth measurements on predicting the individual growth response to GH treatment, and to elucidate the possible reasons for the limited accuracy of current growth prediction models for GH-treated children.

METHODS

Short-term growth measurements by knemometry and stadiometer in 99 short, GH-treated children (27 girls, 72 boys), aged 10.3 +/- 2.3 years, from the Children's University Hospital, Leipzig, Germany.

RESULTS

GH treatment significantly accelerated the mean height velocity (HV) from 4.3 +/- 1.0 to 8.1 +/- 1.8 cm/year during the first year of treatment, the average height standard deviation score (SDS) shifted by +0.52 SD. The variation in HV also increased, from S(2) = 1.0 before to S(2) = 3.4 cm(2)/year(2) during treatment. Lower leg length (LLL) velocity accelerated from 1.6 +/- 0.7 before treatment to 3.4 +/- 1.0 cm/year during the first 8 weeks of treatment. Four coefficients of correlation appeared clinically meaningful: (1) LLL velocity vs. body HV during the first year of GH treatment (r = 0.87), indicating that GH acts simultaneously on leg and rump growth; (2) early (first 8 weeks) LLL velocity vs. 1-year body HV during treatment, with r = 0.61 (R(2) = 0.38), indicating that 38% of the variation in HV during the first year of treatment is already predictable by an initial 8-week period of knemometry; (3) early (first 8 weeks) LLL velocity vs. 1-year LLL velocity during treatment, with r = 0.63 (R(2) = 0.39), and (4) early (first 8 weeks) LLL velocity vs. later LLL velocity, up to the end of the first year, with r = 0.53 (R(2) = 0.28) indicating that the early response on lower leg growth persists for at least 1 year of GH treatment.

CONCLUSIONS

(1) Thirty-eight percent of the variation in HV during the first year of GH treatment is predictable by an initial 8-week period of knemometry. This parallels early changes in biochemical markers of bone turnover after GH treatment. (2) There is evidence for a baseline variability in HV both in healthy children and in children with growth disorders that make growth prediction difficult.

Neurobehavioral and autonomic effects of hammock positioning in infants with very low birth weight

PURPOSE

This study was designed to determine whether supine positioning of infants born preterm in a hammock instead of the prone position affects their neuromuscular maturity, growth, and autonomic stability.

METHODS

Twenty healthy infants who were born premature with very low birth weight (VLBW) (<1500 g) were randomized into two groups. Subjects were pair-matched for weight (difference less than 100 g), gestational age (difference less than eight days), and postnatal age (difference less than eight days). Ten infants were placed supine in a hammock for three hours daily for ten consecutive days, and ten infants were maintained nested in the prone position. Neuromuscular maturity (based on three neurological parameters adopted from the Ballard examination), heart rate, respiratory rate, and weight gain (g/cal) were compared between the groups.

RESULTS

Compared with nested prone positioning, supine positioning in a hammock was associated with a higher neuromuscular maturity score (p < 0.003) and a more relaxed condition, as expressed by lower heart rate and respiratory rate (p < 0.05 and p < 0.01, respectively).

CONCLUSIONS

Maintaining infants who were born preterm with VLBW in the supine position in a hammock may positively affect their autonomic stability and neuromuscular maturity.

Kindling-induced overexpression of Homer 1A and its functional implications for epileptogenesis

Despite an extensive research on the molecular basis of epilepsy, the essential players in the epileptogenic process leading to epilepsy are not known. Gene expression analysis is one strategy to enhance our understanding of the genes contributing to the functional neuronal changes underlying epileptogenesis. In the present study, we used the novel MPSS (massively parallel signature sequencing) method for analysis of gene expression in the rat kindling model of temporal lobe epilepsy. Kindling by repeated electrical stimulation of the amygdala resulted in the differential expression of 264 genes in the hippocampus compared to sham controls. The most strongly induced gene was Homer 1A, an immediate early gene involved in the modulation of glutamate receptor function. The overexpression of Homer 1A in the hippocampus of kindled rats was confirmed by RT-PCR. In order to evaluate the functional implications of Homer 1A overexpression for kindling, we used transgenic mice that permanently overexpress Homer 1A. Immunohistochemical characterization of these mice showed a marked Homer 1A overexpression in glutamatergic neurons of the hippocampus. Kindling of Homer 1A overexpressing mice resulted in a retardation of seizure generalization compared to wild-type controls. The data demonstrate that kindling-induced epileptogenesis leads to a striking overexpression of Homer 1A in the hippocampus, which may represent an intrinsic antiepileptogenic and anticonvulsant mechanism in the course of epileptogenesis that counteracts progression of the disease.

Pelvic haemophilic pseudotumour: management of a patient with high level of inhibitors

Haemophilic pseudotumour (HP) is a rare but very serious complication of haemophilia. HP affects mainly patients with severe haemophilia and those who have developed antibodies to factor VIII or factor IX. We report on a 45-year-old man with haemophilia A and high titres of inhibitors who developed an extensive HP with progressive destruction of the right ilium over a period of 12 years. The different therapeutic options (conservative management by replacement therapy, surgical approach, radiotherapy, percutaneous evacuation with secondary refilled cavity and transcatheter arterial embolization) are reviewed.

The muscle-specific enolase is an early marker of human myogenesis

In higher vertebrates, the glycolytic enzyme enolase (2-phospho-D-glycerate hydrolase; EC 4.2.1.11) is active as a dimer formed from three different subunits, alpha, beta and gamma, encoded by separate genes. The expression of these genes is developmentally regulated in a tissue-specific manner. A shift occurs during development, from the unique embryonic isoform alphaalpha, towards specific isoforms in two tissues with high energy demands: alphagamma and gammagamma in the nervous system, alphabeta and betabeta in striated muscles. The alphaalpha remains widely distributed in adult tissues. Here we report the results of the first extensive study of beta enolase expression during human development. Indeed, the beta subunit is specifically expressed at early stages of human myogenesis. Immunocytochemical analyses demonstrated that it is first detected in the heart of 3-week-old embryos and in the myotomal compartment of somites from 4-week-old embryos. At this stage, the muscle-specific sarcomeric protein titin is expressed in this structure, which will give rise to all body skeletal muscles, but embryonic myosin heavy chain is not yet present. Analyses at the protein level show that, during human ontogenesis, myogenesis is accompanied by an increase in beta enolase expression and by a decrease in the expression of the two other alpha and gamma subunits. Furthermore, beta enolase subunit is expressed in proliferating myoblasts from both embryonic and post-natal muscles. In addition, clonal analysis of primary cell cultures, obtained from the leg muscle of a 7-week-old human embryo, revealed that the beta subunit is present in the dividing myoblasts of all four types, according to the classification of Edom-Vovard et al. [(1999) J Cell Sci 112: 191-199], but not in cells of the non-myogenic lineage. Myoblast fusion is accompanied by a large increase in beta enolase expression. Our results demonstrate that this muscle-specific isoform of a glycolytic enzyme (beta enolase) is among the earliest markers of myogenic differentiation in humans.

Gap junction proteins in inhibitory neurons of the adult barrel neocortex

Recent studies indicate that electrical coupling among cortical neurons may persist throughout development; electrophysiological recordings made in cortical slices from young rats reveal that numerous GABAergic neurons are electrically coupled. To determine whether these in vitro findings reflect an inhibitory neural circuit that could be functionally relevant in vivo in adult rodents, we sought to identify whether inhibitory, parvalbumin-containing neurons of the mature cortex express gap junction proteins. Immunohistochemistry was used to examine the laminar distribution of the gap junction-forming proteins connexin 32 (Cx32), connexin 36 (Cx36) and connexin 43 (Cx43) in the somatosensory cortex of the adult mouse. Double labeling immunofluorescence identified Cx32, Cx36 and Cx43 in cortical neurons that were immunoreactive (-ir) for the neuronal markers neurofilament 145 kDa and neuronal nuclei (NeuN). Parvalbumin-ir neurons throughout the cortical laminae were labeled with Cx32-ir, Cx36-ir and Cx43-ir. Stereological methods were used to quantify the extent of parvalbumin colocalization with connexins. Analysis indicated that approximately 40% of parvalbumin-ir neurons were double labeled with either Cx32-ir or Cx43-ir, and approximately 50% of parvalbumin-ir neurons were double labeled with Cx36. These findings establish an anatomical substrate for widespread electrical coupling of neurons in somatosensory cortex and suggest that gap junctions among inhibitory interneurons may persist into adulthood, providing an important mechanism for neuronal communication.

Computer-guided, population-based screening system for growth disorders (CrescNet) and on-line generation of normative data for growth and development

The mean age at which the diagnosis of growth disorders such as Turner's syndrome, growth hormone (GH) deficiency or true GH-dependent gigantism is established is still rather late in many countries around the world. In addition, the question of secular trends in a given population and the rate at which childhood obesity is increasing in industrialized countries make it mandatory to establish a time-adapted system to develop percentiles for body height, weight and body mass index (BMI) and also to develop a screening system for growth disorders. In 1998 we established a network, now involving more than 160 paediatric practices in Germany and seven paediatric endocrinology departments. Paediatricians record heights, weights and growth velocities of all children in their care and systematically feed the data into the database at our centre usually by mailing formatted, structured data tickets. Data are then continuously analysed at the centre and the paediatricians in the network are informed immediately about their individual patients' growth situations via phone or E-mail (feedback system). Regular annual conferences including structured reports, scientific presentations and discussion groups are organized for all participants at our centre. By May 2001, the data of 83,721 children and adolescents had been analysed. The mean values for height were 1-1.5 cm higher than the mean values in the German Synthetic Growth Curve, which serves as an internal standard. However, and most importantly, in comparison with the internal standard and historical normative data from Germany and Switzerland, there is a continuous increase in the 97th percentile for weight and BMI, while the third percentile remains unchanged. In addition, many children with short stature and tall stature due to a variety of endocrine disorders and genetic diseases which had not been diagnosed previously are now being identified. In conclusion, the databank allows for a continuous adaptation of normative curves based on a large number of children in a given population, i.e. eastern Germany. Secondly, the system allows for detection of pathological growth curves and is already serving to diagnose growth disorders in a defined population in a systematic way.