A new mutation of the glucose-6-phosphatase gene in a 4-year-old girl with oligosymptomatic glycogen storage disease type 1a

A 4-year-old German girl was diagnosed as having glycogen storage disease type la and showed no other marked symptoms except hepatomegaly. The glucose-6-phosphatase activity in the liver was approximately 1.5% to 5.0% of normal values, and molecular analysis revealed compound heterozygosity for R83C and the novel mutation N264K. This result indicates that there is a wide clinical variation of glucose-6-phosphatase deficiency. DNA analysis is helpful for confirmation of the diagnosis, as well as establishment of the genotype and phenotype correlation in glycogen storage disease type 1a.

Pinless external fixation. Indications and preliminary results in tibial shaft fractures

A major drawback of conventional fixator systems is the penetration of the fixator pins into the medullary canal. The pins create a direct link between the medullary cavity and the outer environment. The new AO pinless fixator bypasses this disadvantage by clamping its trocar points onto the outer cortex without penetrating it. Thus, exposure and consequent contamination of the medullary cavity does not occur. The clinical use of this easily manageable fixator with no drilling requirement is for tibial fractures in which the general and local conditions are poor or the infrastructure of the clinic is inadequate for primary internal stabilization or both. All options for a later conversion to internal fixation remain open. For highly unstable tibial shaft fractures, the pinless fixator can be applied as an additional, minimally invasive, external, locked system to increase the stability of intramedullary nail fixation. The pinless external fixator can be combined favorably with the standard AO tubular system and is a valuable addition to the existing fixator systems.

Establishment of a human placental endothelial cell line with extended life span after transfection with SV 40 T-antigens

Studies utilizing microvascular human endothelial cells are relatively few because of substantial difficulties in isolation and cultivation, respective limited proliferation capability and functional variation of primary cells. To facilitate the closer examination of capillary endothelial characteristics, we isolated microvascular endothelial cells from full-term placenta and transfected the cells via lipofection with pRNS-1, encoding for the small and large T-antigens of SV 40. One cell line, HPEC-A1, with a largely extended life span was isolated and kept in culture for up to 80 cumulative population doublings. The cell line HPEC-A1 expressed SV 40 T-antigens and exhibited endothelial characteristics identical to primary cells, such as the uptake of low density lipoprotein, binding of Ulex europaeus lectin I, and the expression of von Willebrand factor, thrombomodulin-alpha, VE-cadherin, and a set of integrins.

Fastest reduction of posttraumatic edema: continuous cryotherapy or intermittent impulse compression?

Sixty patients with foot or ankle trauma were randomized and treated in three groups. In intermittent impulse compression, an air pad under the foot was inflated every 20 seconds, thus activating the venous foot pump. In continuous cryotherapy, ice water circulates between the ice box and the cold pad. The ice water was changed once per day. In standard therapy, the injured extremity was treated with cool packs, which were changed 4 times per day. Beginning at admission, every 24 hours the circumference was measured around the ankle, midfoot, and forefoot. After 24 hours of treatment, there was a 47% reduction in swelling with the A-V impulse System, 33% with continuous cryotherapy, and 17% with cool packs. After 4 days of postoperative treatment, the A-V impulse System reduced the swelling by 74% versus 70% with continuous cryotherapy and 45% with cool packs. Both new methods are preferable to cool packs. Because of the better preoperative results, the A-V impulse System proved to be the most effective device.

Cerebellar atrophy and prognosis after temporal lobe resection

OBJECTIVE

Experimental data indicate inhibitory effects of the cerebellum on seizure activity. Structural damage such as cerebellar atrophy, which is a common finding in patients with chronic epilepsy, may reduce these effects.

METHODS

Outcome after temporal lobectomy was studied in 78 consecutive patients, with or without cerebellar atrophy diagnosed by MRI.

RESULTS

Thirty five patients (45%) showed cerebellar atrophy. At a mean follow up of 14.6 (range, 6-40) months, 50 patients (64%) had no postoperative seizures. In these patients, the frequency of cerebellar atrophy was significantly lower (34%) than in patients who relapsed (64%, p < 0.01). Occurrence of generalised tonic-clonic seizures (GTCS) within two years before surgery, occurrence of GTCS at any time preoperatively, long duration of epilepsy, and older age at surgery were also associated with recurrence of seizures. Multiple logistic regression analysis suggested occurrence of GTCS within two years before surgery and cerebellar atrophy as the main predictive indicators. When both factors were present, the percentage of patients remaining seizure free since surgery fell to 30%, compared with 60% when only GTCS were present, 78.6% when only cerebellar atrophy was present, and 87.5% when both factors were absent.

CONCLUSIONS

Cerebellar atrophy shown by MRI was a frequent finding in surgically treated patients with temporal lobe epilepsy. The presence of cerebellar atrophy seems to worsen the prognosis after temporal lobe resection.

Sulfide-quinone reductase from Rhodobacter capsulatus. Purification, cloning, and expression

A sulfide-quinone oxidoreductase (SQR, EC 1.8.5.'.) has been purified to homogeneity from chromatophores of the non-sulfur purple bacterium Rhodobacter capsulatus DSM 155. It is composed of a single polypeptide with an apparent molecular mass of about 55 kDa, exhibiting absorption and fluorescence spectra typical for a flavoprotein and similar to the SQR from the cyanobacterium Oscillatoria limnetica. From N-terminal and tryptic peptide sequences of the pure protein a genomic DNA clone was obtained by polymerase chain reaction amplification. Its sequence contains an open reading frame of 1275 base pairs (EMBL nucleotide sequence data base, accession no. X97478X97478) encoding the SQR of R. capsulatus. The deduced polypeptide consists of 425 amino acid residues with a molecular mass of 47 kDa and a net charge of +9. The high similarity (72%)/identity (48%) between the N termini of the cyanobacterial and the bacterial enzyme was confirmed and extended. Both enzymes exhibit the FAD/NAD(P) binding betaalphabeta-fold (Wierenga, R. K., Terpstra, P., and Hol, W. G. S. (1986) J. Mol. Biol. 187, 101-107). The complete sequence of the SQR from R. capsulatus shows further similarity to flavoproteins, in particular glutathione reductase and lipoamide dehydrogenase. The cloned sqr was expressed in Escherichia coli in a functional form.

Cerebellar atrophy decreases the threshold of carbamazepine toxicity in patients with chronic focal epilepsy

BACKGROUND

Cerebellar atrophy (CA) is a frequent finding in patients with chronic epilepsy. Since gaze-evoked nystagmus, dizziness, and ataxia are some of the typical adverse effects (AEs) of the dose-dependent toxicity of carbamazepine, preexisting CA could possible explain in part the interindividual variation in the tolerance of high serum concentrations of carbamazepine.

OBJECTIVE

To determine whether CA reduces the threshold for overdose symptoms with carbamazepine in patients with chronic focal epilepsy in a prospective study.

DESIGN

Cohort study.

SETTING

A fourth-level epilepsy center to which patients were referred.

PATIENTS

Twenty-six consecutive patients with chronic focal epilepsy were prospectively studied while they were receiving high-dose monotherapy with carbamazepine. Patients were slowly titrated to doses at which the first toxic AEs of carbamazepine occurred. The determination of multiple serum levels was carried out, together with an evaluation of toxicity that comprised a standardized neurologic examination, a questionnaire for AEs, and posturography.

MAIN OUTCOME MEASURES

Serum concentrations of carbamazepine at the occurrence of the first dose-dependent AEs were related to the presence or absence of CA in magnetic resonance imaging studies as rated by 2 independent and blinded neuroradiologists.

RESULTS

In 9 patients (35%), magnetic resonance imaging scans revealed moderate (n = 7) or severe (n = 2) CA. In these patients, gaze-evoked nystagmus (P = .001, log rank test), dizziness (P = .008), and ataxia of stance as measured by posturography (P = .02) occurred at significantly lower serum concentrations of carbamazepine compared with patients without CA. This was also found for the first individually observed AE (P = .03).

CONCLUSION

Cerebellar atrophy occurs in a considerable percentage of patients with chronic focal epilepsy and obviously increases the susceptibility for cerebellar AEs of carbamazepine.

Isolation and cultivation of endothelial cells derived from human placenta

Endothelial cells were isolated from human full-term placenta by perfusion with trypsin solution via the umbilical cord vein. Human placental endothelial cells (HPEC) were successfully grown and kept in culture. HPEC exhibited endothelial characteristics as judged by morphology of confluent monolayers, staining with low density lipoprotein, binding of Ulex europaeus I lectin, and immunostaining against von Willebrand factor, alpha-thrombomodulin, VE-cadherin and a series of integrins. Different growth requirements and particular morphological characteristics indicated the different vascular origin of HUVEC and HPEC.

[Bioavailability of two verapamil formulations following repeated administration in steady-state conditions. An open, two-period, crossover study]

The relative bioavailability of a new formulation of verapamil (CAS 52-53-9, Veramex 40) in comparison to a standard formulation was investigated in an open two-period cross-over study in 16 healthy volunteers under steady state conditions of 7 days duration each. For the estimation of verapamil a selective HPLC-method was used with fluorescence detection after direct injection and enrichment by column switching enabling a simultaneous separation and analysis of verapamil and N-norverapamil. The bioavailability was estimated using areas under the concentration-time curves (AUC), maximum serum concentrations (Cmax) and peak-trough fluctuation (PTF). Bioequivalence was tested calculating the 90% confidence intervals (ANOVAlog). The mean verapamil plasma profile after the test substance was up to 1.5 h slightly lower than the corresponding curve after the reference substance, thereafter slightly higher plasma levels up to 7 h were observed after the test substance. The individual plasma profiles had a similar variance, and hardly any difference was discernible between the two drugs. A similar behaviour was also seen for N-norverapamil. A mean relative bioavailability of 101% was observed after the test substance both for verapamil and N-norverapamil. The mean maximum plasma concentrations for verapamil and N-norverapamil were 50.0 and 49.7 ng/ml, respectively. After the standard formulation the corresponding values were 50.4 and 50.3 ng/ml. The mean PTF-values for verapamil and N-norverapamil were 178 and 76.6% after the test substance and 182 and 79.6% after the standard formulation, respectively. The 90% confidence intervals for AUC, Cmax and PTF for verapamil and N-norverapamil are completely within the accepted range of 80 to 125% for AUC, Cmax and PTF. Therefore bioequivalence between both formulations can be stated.

The vascular endothelial cell specific membrane antigen HECMA 112 is immunochemically indistinguishable from vascular VE-cadherin

The human endothelial membrane antigens HECMA 112 and VE-cadherin were immunochemically compared. The antibodies 1.3.1 against HECMA 112 and 7B4 against VE-cadherin recognized the same protein in extracts of tissue as well as of cells. The antigen HECMA 112 was immunoprecipitated by anti-VE-Cadherin antibody 7B4.

[Current status of therapy of subtrochanteric femoral fractures]

Operative treatment of subtrochanteric femur fractures is demanding. The implants available follow different biomechanical and surgical principles. Extramedullary implants like the condylar blade plate and the dynamic condylar screw require subtle surgical and indirect reduction techniques. Intramedullary implants like intramedullary hip screws and interlocking nails are biomechanically advantageous. In contrast to the extramedullary implants these fixations can stand postoperative weight-bearing. The different operative techniques for the fixation of subtrochanteric fractures are presented and evaluated. Current trends in treatment rationales are outlined.

Reduction of cytochromes with menaquinol and sulfide in membranes from green sulfur bacteria

Reduction of cytochromes in chlorosome-free membranes of Chlorobia was studied anaerobically, with an LED array spectrophotometer. For Chlorobium tepidum these membranes contained 0.2 moles cytochrome per mole of bacteriochlorophyll a. The observed change upon complete reduction of oxidized membranes with dithionite could be satisfactorily fitted with three cytochrome components having absorption peaks at 553 (cyt c), 558 and 563 nm (cyt b), in relative amounts of 5:1:2. About 20% of total cytochrome 553 were reducible by ascorbate. Menaquinol reduced all of the 553-component, and this reduction was sensitive to stigmatellin, NQNO and antimycin A. The reduction was insensitive to KCN. However, it was transient at low concentrations of menaquinol in the absence of KCN, but permanent in its presence, demonstrating that electron transport into an oxidation pool was blocked. The 563-component was only slightly reduced by menaquinol unless NQNO or antimycin were present. The stimulation of cytochrome 563-reduction by these inhibitors was more pronounced in the presence of ferricyanide. This phenomenon reflects 'oxidant-induced reduction' of cytochrome b and demonstrates that a Q-cycle is operative in Chlorobia. Also, sulfide fully reduced cytochrome 553, but more slowly than menaquinol. KCN inhibited in this case, as did stigmatellin, NQNO and antimycin A. NQNO was a better inhibitor than antimycin A. Cytochrome 563 again was hardly reduced unless antimycin A was added. The effect was more difficult to observe with NQNO. This supports the conclusion that sulfide oxidation proceeds via the quinone pool and the cytochrome bc-complex in green sulfur bacteria.

[Osteosynthesis of proximal femoral fractures with the modular interlocking system of unreamed AO femoral intramedullary nail. Initial clinical results]

The unreamed femoral nail system (UFN) features highly versatile proximal interlocking options for the treatment of a wide range of femoral fracture patterns and combinations. Besides standard interlocking modes for diaphyseal fractures, special interlocking options for subtrochanteric fractures and ipsilateral neck/shaft fractures are available. Two aiming arms can be attached to the insertion handle of the nail in a modular fashion. The standard aiming arm is designed for transverse static or dynamic locking. The special aiming arm permits spiral blade, 130 degrees, and miss-a-nail interlocking. From August 1992 to July 1994, in 10 out of 55 UFN implantations the special interlocking options were used. In 9 subtrochanteric fractures the spiral blade interlocking and in one ipsilateral neck/shaft fracture the miss-a-nail cancellous screw interlocking was applied. ASIF type A fractures with closed soft tissue damage prevailed. Fracture healing was uneventful and no implant complications or loss of reduction have been observed.

[The AO external clamp fixator. New techniques in external stabilization of tibial fractures]

A serious disadvantage of conventional external fixators is the opening of the medullary canal. This creates a direct communication between the canal and the exterior. The new pinless external fixator does not have this disadvantage. The clamps of the new fixator system do not penetrate cortical bone, they simply rest on the cortical surface. The clinical indications of this easily managed system are fractures of the tibial shaft in cases in which primary internal fixation is precluded either by precarious local or general conditions, or even by a lack of infrastructure. In such situations the pinless external fixator is an excellent device to achieve a good fracture stabilisation rapidly, while leaving open all subsequent alteration of treatment. In case of secondary change to an intramedullary nail the pinless fixator facilitates the procedure, because this fixator can be also used as an distractor during nailing. Furthermore this fixator can be combined with any intramedullary nail to increase the stability in case of very proximal or distal as well as highly instable shaft fractures. The clamps of the pinless external fixator set are used in combination with the standard AO fixator system.

Pinless calcaneus traction: a preliminary report

Calcaneus traction with a Steinmann-pin or K-wire inserted into the dorsal aspect of the calcaneus is a common temporary procedure in fractures of the lower leg when internal fixation has to be delayed. Infection due to this simple manoeuvre is rare, but is a very serious complication. In 1991, a so-called pinless external fixator was introduced in clinical trials, based on the idea of external fixation without transosseus pins, thus preserving local blood supply and lowering the risk of pin track infection. This pinless clamp also represents a handy tool for calcaneus traction. We have used this pinless clamp for calcaneus traction in 39 patients without any major problems or complications. Of these, 29 patients were scheduled for delayed internal fixation, and in 10 patients this clamp was used intraoperatively in closed tibial nailing for traction on the fracture table. Tips and tricks for the use of this pinless clamp, and its advantages and disadvantages are discussed.

[Clinical results with the limited contact DCP plate of titanium--a prospective study of 504 cases]

From the beginning of 1988 to July 1991, ten Swiss and German clinics undertook to document all cases of internal fixation using the titanium LC-DCP as part of a prospective multicenter study. The follow-up period was 14.2 months on average. The clinical results of 504 fixations were convincing. The follow-up rate was 72%. Of these, 95% healed without complication. The most frequent complication was delayed healing which occurred in 2.5% of cases. The infection rate was low (1.1%). A separate comparison of DCP fixations on the tibial shaft in 1984-1988 demonstrated the obvious biological compatibility of the new plate and shows that excellent results can be obtained using plate fixation.

A transcription unit for the Rieske FeS-protein and cytochrome b in Chlorobium limicola

A transcription unit petCB from Chlorobium limicola is described. The leading gene petC codes for a Rieske FeS-protein of 19.04 kDa with 181 amino acid residues. The following gene petB codes for a cytochrome b of 47.48 kDa with 428 amino acid residues. The transcription unit lacks a third gene pet-A for cytochrome c 1 or-f, which is found in the fbc-operons of gram-negative bacteria. In the derived amino acid sequence for the Rieske FeS-protein the four cysteines and the 2 histidines are conserved in the peptides binding the 2Fe2S-cluster, although the redox potential of the cluster is about 150 mV more negative in Chlorobium. The gene for cytochrome b includes the coding region for an N-terminal, positively charged extension which is typical for Chlorobium. The gene is not split into two parts for cytochrome b 6 and subunit IV. However, a fourteenth amino acid between the two histidines in the fourth, putative transmembrane helix, and the lack of an eighth transmembrane helix at the C-terminus, among other features, clearly resemble the cytochrome b 6 f-complexes. Therefore, the separation into b 6 f- and bc 1-type complexes during evolution must have occurred before the split of the gene.

Routine application of the pinless external fixator

One serious disadvantage of conventional fixator systems is the need to open the medullary space, hence creating a direct communication with the exterior. The new pinless external fixator does not have this major disadvantage, because the fixator clamps simply rest on the cortical bone without penetrating it. Clinically, this easily managed system is intended for fractures of the tibia in cases in which primary internal fixation is precluded either by precarious local or general conditions or by infrastructural problems. In such situations the new pinless fixator is an excellent device with which to achieve good stabilization of the fracture rapidly, while leaving open all options for subsequent alteration of treatment. If the surgeon decides to convert to locked intramedullary nailing, the pinless fixator facilitates the new approach, because it can be used as a distractor and makes it unnecessary to transfer the patient to a fracture table.

Documentation

In the period from 1. January to 31. December 1992, the new pinless external fixator was applied in eight European and North American clinics as part of a prospective multicentric study run by the AO/ASIF Documentation Centre. The aim of this study was to determine the indications, handling, and clinical results with the new fixator. The new pinless fixator was used 77 times on a total of 75 patients. The main indications were fresh tibial shaft fractures for which immediate definitive treatment was impossible. The majority of cases were secondarily stabilized with an unreamed tibial nail once the local and/or general condition of the patient had improved. In the remaining cases the pinless fixator was used for calcaneal and tibial head traction, segment transport and temporary stabilization in cases of tibial infection. Only after long-term application of the fixator was local infection at the pin site observed. There were no other complications. The new pinless fixator is a valuable addition in the treatment of fresh tibial fractures, in particular, in those cases which cannot be primarily treated due to contributing factors whether local or general.

Skier's thumb--the significance of bony injuries

In a retrospective study to determine the anatomic nature of injuries in thumbs that were treated surgically for either fracture or instability, we reviewed 63 consecutive patients with acute skier's thumb injury. Of the 63 thumbs, 25 (40%) had a fracture. Surgical exploration showed 2 fracture types: a fragment that was attached to the ulnar collateral ligament, and a fragment that was not attached to the ulnar collateral ligament. The 1st type, corresponding to true avulsion fracture of the ulnar collaternal ligament, was found in 8 cases; the same fracture type was seen in another 7 cases, with an isolated fragment that was not attached to the ligament. Such an isolated fragment was observed in 10 other cases in which the ulnar collateral ligament was completely disrupted. This type of bony fragmentation cannot be differentiated from a bony avulsion of the ulnar collateral ligament on routine films. Therefore, stress testing the injured thumb is mandatory even when bony avulsion fracture with minimal displacement is suspected from a radiograph, as indeed the fracture may not be a bony avulsion but may be a fragmentation of the ulnar volar aspect of the proximal phalanx associated with a complete disruption of the ulnar collateral ligament.

[Classification of proximal femoral fractures]

Based on the AO Classification of Fractures, the classification of fractures of the proximal femur will be explained. Especially the sub- and pertrochanteric fractures, as well as the fractures of the femoral neck will be considered. During the period from 1980-1989 26,126 fractures of the proximal femur were documented in the AO/ASIF Documentation Center. These fractures will be discussed regarding following aspects: dispersion of age and fractures, pre-existing systemic illnesses, general and local postoperative complications, choice of implant.