Identification of novel and known mutations in the genes for keratin 5 and 14 in Danish patients with epidermolysis bullosa simplex: correlation between genotype and phenotype

Epidermolysis bullosa simplex (EBS) is a group of autosomal dominant inherited skin diseases caused by mutations in either the keratin 5 (K5) or the keratin 14 (K14) genes and characterized by development of intraepidermal skin blisters. The three major subtypes of EBS are Weber-Cockayne, Koebner, and Dowling-Meara, of which the Dowling-Meara form is the most severe. We have investigated five large Danish families with EBS and two sporadic patients with the Dowling-Meara form of EBS. In the sporadic Dowling-Meara EBS patients, a novel K14 mutation (N123S) and a previously published K5 mutation (N176S) were identified, respectively. A novel K14 mutation (K116N) was found in three seemingly unrelated families, whereas another family harbored a different novel K14 mutation (L143P). The last family harbored a novel K5 mutation (L325P). The identified mutations were not present in more than 100 normal chromosomes. Six polymorphisms were identified in the K14 gene and their frequencies were determined in normal controls. These polymorphisms were used to show that the K14 K116N mutation was located in chromosomes with the same haplotype in all three families, suggesting a common ancestor. We observed a strict genotype-phenotype correlation in the investigated patients as the same mutation always resulted in a similar phenotype in all individuals with the mutation, but our results also show that it is not possible to predict the EBS phenotype merely by the location (i.e., head, rod, or linker domains) of a mutation. The nature of the amino acid substitution must also be taken into account.

Molecular cytogenetic detection of 9q34 breakpoints associated with nail patella syndrome

The nail patella syndrome (NPS1) is an autosomal dominant disorder characterised by dysplasia of the finger nails and skeletal abnormalities. NPS1 has been mapped to 9q34, to a 1 cM interval between D9S315 and the adenylate kinase gene (AK1). We have mapped the breakpoints within the candidate NPS1 region in two unrelated patients with balanced translocations. One patient [46,XY,t(1;9)(q32.1;q34)] was detected during a systematic survey of old cytogenetic files in Denmark and southern Sweden. The other patient [46,XY,t(9;17)(q34.1;q25)] was reported previously. D9S315 and AK1 were used to isolate YACs, from which endclones were used to isolate PACs. Two overlapping PAC clones span the 9q34 breakpoints in both patients, suggesting that NPS1 is caused by haploinsufficiency due to truncation or otherwise inactivation of a gene at or in the vicinity of the breakpoints.

Necrosis of the femoral head after kidney transplantation

We reviewed the medical records of 750 patients (445 men, 305 women), who had received a kidney transplant during the period 1968-1995, for any sign of necrosis of the femoral head. For post-operative immunosuppression, 374 patients had received high-dose corticosteroids (average 12.5 g during the first year post-operatively), while 376 patients had received low-dose corticosteroids (average 6.5 g during the first year post-operatively) and cyclosporin A. Survival curves according to Kaplan and Meier (J Am Stat Ass 1958: 53: 457-481) were constructed. In the high-dose steroid group, 42/374 patients (11.2%) developed femoral head necrosis, at an average of 26.2 months post-transplantation. In the low-dose steroid group, only 19/376 (5.1%) patients developed this complication, at an average of 20.5 months post-transplantation. This difference in numbers of femoral head necroses was highly significant (p < 0.005). We conclude that steroid doses should be minimized whenever feasible in post-transplant immunosuppression therapy.

Monitoring protein refolding induced by disulfide formation using capillary isoelectric focusing-electrospray ionization mass spectrometry

Rapid growth in the biotechnology industry has led to a dramatic increase in attention to the protein folding problem. Understanding protein-folding pathways is essential to the production of biopharmaceuticals since commercial production of recombinant proteins often requires a protein-refolding process for recovery of high yields. Protein folding coupled to the formation of disulfide bonds presents one of the simplest approaches to studying folding intermediates. On-line capillary isoelectric focusing-electrospray ionization mass spectrometry (CIEF-ESIMS) is demonstrated for kinetic studies of disulfide bond-induced protein refolding. Refolding intermediates of bovine pancreatic ribonuclease A, a model system for this study, are blocked at different stages by alkylating free thiols with iodoacetate. The alkylation reaction results in the introduction of charge (-1) and mass (59) differences for each alkylation site, providing the means for predictable separation and direct identification of refolding intermediates using CIEF-ESIMS. Besides the observation of refolding intermediates containing different numbers of disulfide bonds and even mixed disulfides, the two-dimensional resolving power of CIEF-ESIMS allows the determination of conformational heterogeneity among groups of refolding intermediates.

[Relevance of the 112-emergency calls among the clientele of the emergency department of the Herlev hospital admitting office]

It is a common view, shared by Emergency Department staff and ambulance crews, that a large number of patients unnecessarily use Emergency Service ambulances instead of transporting themselves to the hospital by other, more appropriate means. In this retrospective study, 528 consecutive Emergency Service calls to the Herlev Hospital Casualty/Emergency Department during a six week period were reviewed for relevance. Attention was solely aimed at the relevance of the use of Emergency Service ambulances in each case, but not on patient or health care providers' perception of urgency. All calls resulting in admission to hospital were pre-defined as being relevant. Seventeen point six percent of all calls were deemed irrelevant. Thirty-three percent of all calls not resulting in admission were deemed irrelevant. The results confirm Emergency Department health care providers' and ambulance crews' view that Emergency Service ambulances are used inappropriately by the public.

A placebo- and active-controlled randomized trial of prophylactic treatment of seasonal allergic rhinitis with mometasone furoate aqueous nasal spray

BACKGROUND

Topical nasal corticosteroids have become a mainstay of treatment for the symptoms of seasonal allergic rhinitis (SAR). It is likely that topical corticosteroids, by blocking an initial influx of inflammatory cells in the nasal mucosa induced by aeroallergens, may have a preventive effect on nasal allergy symptoms when administered before the pollen season.

OBJECTIVE

This study was designed to assess the efficacy and safety of an 8-week course of mometasone furoate nasal spray (MFNS), 200 micrograms once daily, in the treatment of SAR compared with beclomethasone dipropionate aqueous nasal spray (BDP), 168 micrograms twice daily, and placebo vehicle, when treatment is initiated before the anticipated onset of the ragweed season.

METHODS

Three hundred forty-nine patients with SAR to ragweed pollen from nine centers in the Northeast and Midwest of the United States were randomized to one of the three intranasal study medications (MFNS, 200 micrograms once daily, BDP, 168 micrograms twice daily, or placebo vehicle), starting 4 weeks before the estimated start of the ragweed season.

RESULTS

The proportion of "minimal symptom" days (total nasal symptom score < or = 2) was statistically significantly higher in both the MFNS and BDP groups when compared with the placebo vehicle group (p < 0.01). The two active treatment groups were not statistically significantly different from each other. MFNS and BDP displayed a similar safety profile that did not differ from placebo.

CONCLUSIONS

This suggests that MFNS, 200 micrograms (once daily), is a useful therapy in the prophylactic treatment of SAR.

Local recurrences in giant cell tumour of bone. Long-term follow up of 31 cases

We studied the value of histopathological grading in determining the prognosis of giant cell tumour (osteoclastoma) and the rate of local and distant recurrences in a consecutive series of 31 patients. We found that grading had no prognostic value. Eighteen patients were treated by intralesional curettage and 13 by wide excision. Ten patients (56%), who were all treated by curettage, had local recurrences, but none of the tumours with wide excision recurred (p < 0.05). Five (16%) had local recurrences as well as distant metastases, usually to the lungs. The recurrences developed later than an average of 12 years after primary treatment in 3 patients. Wide excision and life-long follow up should be considered in the management of these tumours.

Epithelial healing in the second eye after corneal abrasion

Corneal epithelial healing velocity was determined in patients admitted to excimer laser photo refractive keratectomy, by daily video planimetry of the denuded area until complete healing. The epithelial healing process was followed in fellow eyes with regard to intervals between surgery of the two eyes of 1 to 10 weeks. In cases where the fellow eye was treated at one week after the first eye, the lesions healed significantly faster in the second eye as compared to patients with longer delay between the two operations.

[Traumatic total rupture of the musculus pectoralis major tendon]

Total or partial rupture of the major pectoral muscle is a rare lesion. Early treatment is recommended to regain full strength in the shoulder, but even without surgery 70 to 90% of original strength may be recovered within a year after trauma. We report a case in which a carpenter three months after total rupture of the major pectoral muscle tendon on the dominant side had spontaneously recovered sufficiently to perform his usual job. The diagnosis was visualized by MR imaging. The muscle strength was tested by use of a dynamometer.

The effect of age on the apparent clearance of felbamate: a retrospective analysis using nonlinear mixed-effects modeling

The effects of age on felbamate apparent clearance were examined through a retrospective analysis of plasma concentration data from 700 pediatric and adult epileptic patients (age range, 2-74 years) enrolled in six clinical studies. Patients received felbamate as monotherapy or in combination with either the antiepileptic drugs (AEDs) carbamazepine (CBZ), phenytoin (PHT), or valproate (VPA). Data were analyzed using a nonlinear mixed-effects pharmacostatistical modeling technique (NONMEM). Factors in the model included age, body weight, and concomitant AEDs. Apparent clearance was highest in the very young and decreased during the early teenage years, with minimal changes observed beyond 13 years. Mean apparent clearance values were approximately 40% higher in children (2-12 years) compared with those in adults (13-65 years). This pattern and its magnitude were consistent whether felbamate was administered alone or coadministered with CBZ, PHT, or VPA. The increase in clearance is minimal compared with other AEDs including PHT, CBZ, and phenobarbital. Enzyme-inducing AEDs (CBZ and PHT) increased felbamate apparent clearance by 32-38% relative to monotherapy, whereas coadministration with VPA had a minimal effect on felbamate apparent clearance. Dose/concentration linearity was observed at all ages during mono- or polytherapy. These findings suggest that felbamate dosing should be relatively uncomplicated in children relative to that in adults.

Precision of ultrasonic estimates of choroidal melanoma regression

BACKGROUND

Important prognostic information may be gained from knowledge of the volume and, over time, the change in volume of intraocular tumors such as choroidal melanomas.

METHODS

The precision and time consumption of three different ultrasonographic methods were evaluated. Seven choroidal melanomas were analysed after placement of a ruthenium plaque and again after tumor regression had occurred. Perpendicular ultrasound B-scans were printed and analysed by overlay grid counting or outline tracing of tumor structures to calculate the volume. These two methods, using only two perpendicular scans, were compared with a micro-computer-controlled ultrasonographic three-dimensional rotation scanning system, where each tumor was manually outlined in 20 revolving scan planes

RESULTS

The three-dimensional volume scanning method was the most precise, but also the most demanding in hardware and time consumption.

CONCLUSION

Increased precision and less observer-dependent estimation of shrinkage rate after radiotherapy is available at the cost of sophisticated equipment.

Exercise and reversed pupillary block in pigmentary glaucoma

PURPOSE/METHODS

The effect of exercise on the iris contour was investigated with ultrasound biomicroscopy in two patients with pigmentary glaucoma.

RESULTS/CONCLUSION

Ten minutes of bicycle exercise strikingly increased the iris concavity. After Nd:YAG laser iridotomy the iris remained plane after a repeated exercise test. We believe that exercise increased the ocular pulse, which augmented cyclic aqueous movements through the pupil. Combined with a reverse pupillary block, the resulting intermittent excessive iris concavity caused pigment dispersion.

Tamm-Horsfall glycoprotein in streptozotocin diabetic rats: a study of kidney in situ hybridization, immunohistochemistry, and urinary excretion

Tamm-Horsfall glycoprotein, present only in the kidney thick ascending limb of Henle's loop, was studied here in streptozotocin diabetic rats. Tamm-Horsfall glycoprotein mRNA in situ hybridization was performed on snap-frozen left kidneys; the right kidneys were perfusion-fixed with 4% paraformaldehyde and embedded either in paraffin, for Tamm-Horsfall glycoprotein immunohistochemistry, or in Epon for stereologic measurements. The length of the thick ascending limb of Henle's loop and the amount of glycogen were measured and the ultrastructure of the cells was evaluated. Urinary excretion of Tamm-Horsfall glycoprotein, calcium, magnesium and albumin was measured. After 10 and 50 days' duration of diabetes, kidney weight increased 20 and 41%, respectively and the length of the thick ascending limb of Henle's loop increased 28 and 56%, respectively, compared with controls. Substantial glycogen accumulations were present in the thick ascending limb of Henle's loop, and electron microscopy revealed a significant decrease in organelles and basolateral membranes. After 10 and 50 days' duration of diabetes, in situ hybridization of Tamm-Horsfall glycoprotein mRNA revealed a fourfold decrease, and the immunostaining for Tamm-Horsfall glycoprotein showed a threefold decrease as measured by densitometry. However, urinary Tamm-Horsfall glycoprotein excretion rate was increased fivefold and urinary concentration about twofold. Urinary calcium excretion increased three-fold and magnesium twofold, but urinary albumin excretion was not significantly increased. The increased amount of Tamm-Horsfall glycoprotein, calcium and magnesium in the urine in diabetes occurs here concomitant with severe cellular damage in the thick ascending limb of Henle's loop.

Healing velocity of corneal epithelium evaluated by computer. The effect of topical steroid

To objective determine the area of corneal abrasion, a video camera was connected to a slit-lamp. The videosignal was digitized and analyzed by a computer program. The maximal horizontal and vertical diameters were measured as well as the total abraded area. The algorithms of calculating healing velocity of corneal epithelium are discussed, and this system was tested on patients treated for myopia with a 193 nm ArF excimer laser. It was shown that topical steroid application did not impair corneal epithelial healing velocity.

Video controlled M-mode biometry

To increase the accuracy of intraocular lens power calculation, an interface between an ultrasonic A-scanning device and a personal computer was created, allowing for an on-line interpretation of the ultrasonogram in an M-mode fashion. On the same computer display, a video recording of the movements of the transducer probe relative to the eye was inserted to obtain simultaneous information on the external alignment of the transducer probe. The precision of the experimental set-up in the measurement of intraocular distances was compared with conventional A-scanning procedures run in automatic mode. The video controlled M-mode biometry was found easy to operate and to result in reproducible axial length determination: The median value of the standard deviation was found to be below 0.04 mm as compared to a value of about 0.10 mm with conventional equipment. We concluded that video controlled M-mode biometry has great potential in the endeavour to increase the accuracy of intraocular lens calculation.

In vitro measurement of corneal strain, thickness, and curvature using digital image processing

A video camera, a microscope, and a PC-based digital image processing board were assembled for in vitro studies of corneal biomechanics. Central tangential corneal strain was determined by placing pairs of tiny mercury droplets on the epithelial surface and on the endothelial surface of the cornea. A distance of 3.2 mm could be determined with a standard deviation of 1.2 micron. Central corneal radius of curvature was measured from digital traces of the corneal surface contour. The standard deviation on estimating the radius of an 8 mm steel sphere was 15 microns. Corneal thickness was measured by digital optical pachometry. The standard deviation on measuring a thickness of 1 mm was 4.6 microns. The corneal extensibility was investigated in a total of 10 enucleated human eyes with increased corneal hydration. Tension was applied by varying the intraocular pressure from 2 to 100 mmHg with a column of isotonic saline. The epithelial side corneal strain and the increase in corneal curvature were approximately 1% for a change in intraocular pressure from 2 to 100 mmHg. When a high intraocular pressure was kept constant for 2 h the corneal thickness, radius of curvature, and the epithelial side strain gradually decreased, whereas the endothelial side strain increased. The elastic and visco-elastic behaviour of the human cornea was found to be closely related to changes in corneal hydration. We found digital image processing useful for in vitro biomechanical studies of the cornea.

Prenatal diagnosis of medium-chain acyl-CoA dehydrogenase (MCAD) deficiency in a family with a previous fatal case of sudden unexpected death in childhood

Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency is a potentially fatal inherited disease with a carrier frequency of approximately 1:100 in most Caucasian populations. The disease is implicated in sudden unexpected death in childhood. A prevalent disease-causing point mutation (A985G) in the MCAD gene has been characterized, thus rendering diagnosis easy in the majority of cases. Since the clinical spectrum of MCAD deficiency ranges from death in the first days of life to an asymptomatic life, there are probably other genetic factors--in addition to MCAD mutations--involved in the expression of the disease. Thus, families who have experienced the death of a child from MCAD deficiency might have an increased risk of a seriously affected subsequent child. In such a family we have therefore performed a prenatal diagnosis on a chorionic villus sample by a highly specific and sensitive polymerase chain reaction (PCR) assay for the G985 mutation. The analysis was positive and resulted in abortion. We verified the diagnosis by direct analysis on blood spots and other tissue material from the aborted fetus and from family members.

Felbamate in the treatment of Lennox-Gastaut syndrome

Felbamate (FBM, Felbatol/Taloxa), a new antiepileptic drug (AED), was tested in a placebo-controlled add-on design in 73 patients with therapy refractory Lennox-Gastaut syndrome. Results of the efficacy analysis showed that FBM was statistically significantly more effective (p < 0.05) than placebo for four of five predefined efficacy variables. The total number of seizures, for example, decreased by 26% during treatment with FBM compared with an increase of 5% during placebo (p < 0.001). Retrospective analysis of percentage of patients with specific response rates confirmed results of the predefined efficacy variables. Approximately 50% of patients randomized to FBM obtained at least a 50% reduction in seizure frequency compared with about 15% receiving placebo. In addition, 12-month follow-up data in patients who completed the controlled part of the study confirmed the long-term efficacy of FBM. In general, FBM was well tolerated, with only gastrointestinal symptoms and somnolence seen more often with FBM compared with placebo. FBM is the first compound shown to be effective in a controlled study in patients with Lennox-Gastaut syndrome.

Gene transfer into cultured human epidermis and its transplantation onto immunodeficient mice: an experimental model for somatic gene therapy

To try epidermis as a target for somatic gene therapy we studied transfected primary human keratinocytes grown in culture and grafted onto athymic mice. We have developed a novel technique for grafting cultured epidermal sheets onto mice. First, the graft is placed on the dorsal muscle fascia underneath the mouse skin using the latter as a bandage. Secondly, the mouse skin above the graft is removed, which exposes the grafted skin to open air and thus stimulates terminal differentiation. A novel method for the discrimination between murine and human epidermal cells is also presented, employing in situ hybridization with human Alu repeated DNA sequences. During monolayer culture the keratinocytes were lipofected with the gene for human growth hormone in an Epstein-Barr virus-based expression vector. The cells were allowed to develop a multilayered tissue for 5 d, secreting human growth hormone into the medium at a daily rate of at least 50 ng/cm2 of tissue. The transfected tissues were then grafted onto mice. We detected human growth hormone at levels of up to 2.6 ng/ml in mouse serum for 4 d, but later no human growth hormone could be found, although the transplants survived for months. To investigate the fate of the transfected cells in the transplanted tissue, we labeled them with the beta-galactosidase reporter gene. The cells staining positive for X-gal were found exclusively in the most superficial differentiated layers at 7 d after transplantation. This may be the main reason why no human growth hormone is found in the mouse circulation at this time.

Felbamate in the treatment of refractory partial-onset seizures

Felbamate (FBM) is a new antiepileptic drug (AED) that has been tested in open and controlled studies in patients with therapy-refractory partial-onset seizures. Proof of efficacy is based on results of five controlled studies (three with polytherapy and two with monotherapy). In two of the three polytherapy studies, a classic placebo crossover design was used. The third study used a novel design evaluating the efficacy of FBM in a placebo-controlled parallel design in patients completing an evaluation for epilepsy surgery. The primary efficacy variable in this study was the number of patients who experienced a fourth seizure before the end of the study. Forty-six percent of patients randomized to FBM stopped treatment prematurely because of a fourth seizure compared with 88% randomized to placebo. Two studies investigating the efficacy in monotherapy were performed. Both studies used an identical trial design comparing FBM with a low dosage of valproate (VPA). The efficacy of FBM was found to be superior to the low-dosage VPA for both studies. Open long-term follow-up studies have confirmed the long-term efficacy of FBM for up to 12 months. Overall, FBM was well tolerated in both poly- and monotherapy.

Correction of steroid sulfatase deficiency by gene transfer into basal cells of tissue-cultured epidermis from patients with recessive X-linked ichthyosis

To develop an experimental model for somatic gene therapy we have tried to correct the steroid sulfatase (STS) deficiency in tissue-cultured primary epidermal keratinocytes from patients suffering from recessive X-linked ichthyosis. An efficient Epstein-Barr virus-based vector was constructed, in which full-length steroid sulfatase cDNA is located between an SV40 early promotor and processing signals. After STS gene transfer into cultured basal cells from ichthyotic skin, the cells produce large amounts of enzymatically active steroid sulfatase protein. The subpopulation of transfected cells can be made to produce approximately 100 times more STS activity than normal keratinocytes. Keratinocytes from patients suffering from recessive X-linked ichthyosis display an abnormal phenotype when developing a multilayered tissue in culture: Initially an extensive burst of keratinization is observed, followed by rapid, premature shedding and degradation of most suprabasal cell layers, leaving a culture with hyperproliferative relatively immature keratinocytes. Transfection of these immature ichthyotic cells with the functional STS construct led to an increase in the amount of retained cell material in the culture medium, indicating an increased cell maturation. It is possible to genetically label individual transfected epidermal cells with a reporter gene. Cotransfection experiments with STS and reporter gene vectors show that the cohort of transfected cells had a tendency to develop less rapidly since they became overrepresented in the smaller size classes at the same time the total population was somewhat shifted toward higher cell sizes. We interpret these results as an indication that restoration of the enzymatic activity induces a more normal maturation of the transfected keratinocytes.

Application of molecular and cytogenetic techniques to the detection of a de novo unbalanced t(11q;21q) in a patient previously diagnosed as having monosomy 21

The occurrence of complete autosomal monosomy in man is extremely rare and generally considered to be incompatible with life. Since the introduction of banding techniques in human cytogenetics, several cases of presumptive monosomy for chromosome 21 have nevertheless been reported. However, it has been suggested that most, if not all, of these cases may represent unbalanced translocations or other structural aberrations resulting in only partial monosomy 21. Here we described a patient in whom full monosomy 21 was initially diagnosed by routine karyotyping. Re-examination with a combination of high resolution banding technique, chromosome painting and DNA polymorphism analysis demonstrated the presence of an unbalanced translocation between the long arms of chromosome 11 and 21, respectively. Consequently, the case was re-classified as a partial monosomy for the proximal long arm of chromosome 21.