Disulfide bond structure determination and biochemical analysis of glycoprotein C from herpes simplex virus

A biochemical analysis of glycoprotein C (gC of herpes simplex virus was undertaken to further characterize the structure of the glycoprotein and to determine its disulfide bond arrangement. We used three recombinant forms of gC, gC1(457t), gC1(delta33-123t), and gC2(426t), each truncated prior to the transmembrane region. The proteins were expressed and secreted by using a baculovirus expression system and have been shown to bind to monoclonal antibodies which recognize discontinuous epitopes and to complement component C3b in a dose-dependent manner. We confirmed the N-terminal residues of each mature protein by Edman degradation and confirmed the internal deletion in gC1(delta33-123t). The molecular weight and extent of glycosylation of gC1 (457t), gC1(delta33-123t), and gC2(426t) were determined by treating each protein with endoglycosidases and then subjecting it to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and mass spectrometric analysis. The data indicate that eight to nine of the predicted N-linked oligosaccharide sites on gC1(457t) are occupied by glycans of approximately 1,000 Da. In addition, O-linked oligosaccharides are present on gC1(457t), primarily localized to the N-terminal region (amino acids [aa] 33 to 123) of the protein. gC2(426t) contains N-linked oligosaccharides, but no O-linked oligosaccharides were detected. To determine the disulfide bond arrangement of the eight cysteines of gC1(457t),the protein was cleaved with cyanogen bromide. SDS-PAGE analysis followed by Edman degradation identified three cysteine-containing fragments which are not connected by disulfide linkages. Chemical modification of cysteines combined with matrix-assisted laser desorption ionization mass spectrometry identified disulfide bonds between cysteine 1 (aa 127) and cysteine 2 (aa 144) and between cysteine 3 (aa 286) and cysteine 4 (aa 347). Further proteolysis of the cyanogen bromide-generated fragment containing cysteine 5 through cysteine 8, combined with mass spectrometry and Edman degradation, showed that disulfide bonds link cysteine 5 (aa 386) to cysteine 8 (aa 442) and cysteine 6 (aa 390) to cysteine 7 (aa 419). A similar disulfide bond arrangement is postulated to exist in gC homologs from other herpesviruses.     

Extraocular muscle involvement in sarcoidosis

BACKGROUND: Sarcoidosis is a granulomatous inflammatory disease that may have a variety of ocular and orbital manifestations. The most common ocular manifestation is uveitis, and the most common orbital manifestation is dacryoadenitis. Extraocular muscle involvement in sarcoidosis has rarely been reported. The authors report a case of sarcoidosis involving the extraocular muscles of a 15-year-old boy with bilateral, painful, external ophthalmoplegia and enlargement of all extraocular muscles on computed tomography (CT) scan. RESULTS: Lateral rectus muscle biopsy and transbronchial lung biopsy showed noncaseating granulomas characteristic of sarcoidosis. Cultures and serologic studies excluded fungal and mycobacterial diseases. Treatment with oral corticosteroids improved symptoms and signs. CONCLUSIONS: The authors report the first case of sarcoidosis in a patient with symptomatic extraocular muscle involvement, and only the third case in which extraocular muscle involvement has been shown histologically.     

An autosomal genomic scan for loci linked to prediabetic phenotypes in Pima Indians

Type 2 diabetes mellitus is a common chronic disease that is thought to have a substantial genetic basis. Identification of the genes responsible has been hampered by the complex nature of the syndrome. Abnormalities in insulin secretion and insulin action predict the development of type 2 diabetes and are, themselves, highly heritable traits. Since fewer genes may contribute to these precursors of type 2 diabetes than to the overall syndrome, such genes may be easier to identify. We, therefore, undertook an autosomal genomic scan to identify loci linked to prediabetic traits in Pima Indians, a population with a high prevalence of type 2 diabetes. 363 nondiabetic Pima Indians were genotyped at 516 polymorphic microsatellite markers on all 22 autosomes. Linkage analyses were performed using three methods (single-marker, nonparametric multipoint [MAPMAKER/SIBS], and variance components multipoint). These analyses provided evidence for linkage at several chromosomal regions, including 3q21-24 linked to fasting plasma insulin concentration and in vivo insulin action, 4p15-q12 linked to fasting plasma insulin concentration, 9q21 linked to 2-h insulin concentration during oral glucose tolerance testing, and 22q12-13 linked to fasting plasma glucose concentration. These results suggest loci that may harbor genes contributing to type 2 diabetes in Pima Indians. None of the linkages exceeded a LOD score of 3.6 (a 5% probability of occurring in a genome-wide scan). These findings must, therefore, be considered tentative until extended in this population or replicated in others.     

Biomechanical testing of the spine. Load-controlled versus displacement-controlled analysis

Mechanical testing of the spine can be carried out in either a load-controlled or a displacement-controlled manner. Each method requires certain assumptions and offers different advantages. Dr. W. Thomas Edwards believes that displacement-controlled testing most accurately reflects the in vivo environment, while Drs. Vijay Goel, David Wilder, and Malcolm Pope support the use of the load-controlled method as most logical and easily standardized.     

Transdural spinal cord herniation: imaging and clinical spectra

OBJECTIVE: Many diseases induce asymmetric delays in the visual pathway, resulting in a spontaneous Pulfrich phenomenon (PP). The PP is a visual stereoillusion that may cause difficulties in persons when traveling in cars, crossing the road, or playing ball games. The authors developed and tested a simple new bedside procedure to detect PP. DESIGN: A case series. PARTICIPANTS: Disease simulation in 2 normal subjects and 18 patients with optic neuritis (ON) was examined. Ninety normal subjects were studied to determine normal range of PP. INTERVENTION: The new test, called swinging pen test (SPT), is performed by oscillating a pen by hand. The SPT was compared to a gold standard, a mechanical pendulum (MP). MAIN OUTCOME MEASURES: The authors measured simulated PP in two normal subjects and PP in 18 patients with ON and 90 normal control subjects. The Pearson product-moment correlation (r) and the Spearman rank correlation (rs) between SPT and MP were calculated. RESULTS: The magnitudes of simulated PP determined with the SPT and the MP correlated well (r = 0.92, P < 0.005, and r = 0.96, P < 0.001). Correlation also was good in patients with ON (rs = 0.90, P < 0.05). The positive predictive value of the SPT was 100%, and the negative predictive value was 92%. The PP was absent in all control subjects testing with either pendulum. The normal range for PP varied from -1.40 to 1.52 msec. For the SPT, the intraobserver variability coefficient was 8.2%, and the interobserver variability coefficient was 10.5%. CONCLUSIONS: The authors believe that SPT will be of value to clinicians on bedside evaluation of motion stereopsis dysfunctions. The normal range of PP was approximately +/- -1.5 msec (approximately +/- -1.5 cm), corresponding to a 0.3-log unit neutral density filter).     

Reaction of the cardio-respiratory-system following acetylcholine inhalation and the dependency from the body position on anaesthetised dogs (author's transl)

The bronchomotoric reaction following ACH-aerosol in low concentrations is dependend on the position of the body on dogs. Up till one maximal reaction the increase of the airway resistance is always stronger in the lateral position. Nevertheless the breathing minute volume is constant. Concentration reaction curves will be shown. Arterial blood gases, heart rate, and pressure in the arteria femoralis were also measured. The different strongness of the reaction following ACH-inhalation will be caused by the predominantely unilateral ventilation of the animals in the lateral position.     

Rehabilitation after aortic valve replacement with autologous fascia lata: a sociomedical study

In a series of 50 patients who underwent aortic valve replacement with frame-supported fascia lata, 32 were seen for a combined medical and psychosocial examination 10 to 33 months postoperatively. The investigation included a psychometric test battery and an interview concerning the patient's social and psychological situation at the time of the operation and at follow-up. Twenty-seven patients had improved in their New York Heart Association Functional Classification at the time of follow-up. In most instances NYHA classification correlated well with the patients' subjective opinion on their recovery. Those who for various reasons were not able to return to work did not consider themselves recovered. The employment rate after operation was 66%. There is a great need for more information and support to families as well as for more intensive rehabilitation efforts, especially vocational, for the postoperative patient.