Familial co-segregation and the emerging role of long-read sequencing to re-classify variants of uncertain significance in inherited retinal diseases

Phasing genetic variants is essential in determining those that are potentially disease-causing. In autosomal recessive inherited retinal diseases (IRDs), reclassification of variants of uncertain significance (VUS) can provide a genetic diagnosis in indeterminate compound heterozygote cases. We report four cases in which familial co-segregation demonstrated a VUS resided in trans to a known pathogenic variant, which in concert with other supporting criteria, led to the reclassification of the VUS to likely pathogenic, thereby providing a genetic diagnosis in each case. We also demonstrate in a simplex patient without access to family members for co-segregation analysis that targeted long-read sequencing can provide haplotagged variant calling. This can elucidate if variants reside in trans and provide phase of genetic variants from the proband alone without parental testing. This emerging method can alleviate the bottleneck of haplotype analysis in cases where genetic testing of family members is unfeasible to provide a complete genetic diagnosis.

Targeted adaptive long-read sequencing for discovery of complex phased variants in inherited retinal disease patients

Inherited retinal degenerations (IRDs) are a heterogeneous group of predominantly monogenic disorders with over 300 causative genes identified. Short-read exome sequencing is commonly used to genotypically diagnose patients with clinical features of IRDs, however, in up to 30% of patients with autosomal recessive IRDs, one or no disease-causing variants are identified. Furthermore, chromosomal maps cannot be reconstructed for allelic variant discovery with short-reads. Long-read genome sequencing can provide complete coverage of disease loci and a targeted approach can focus sequencing bandwidth to a genomic region of interest to provide increased depth and haplotype reconstruction to uncover cases of missing heritability. We demonstrate that targeted adaptive long-read sequencing on the Oxford Nanopore Technologies (ONT) platform of the USH2A gene from three probands in a family with the most common cause of the syndromic IRD, Usher Syndrome, resulted in greater than 12-fold target gene sequencing enrichment on average. This focused depth of sequencing allowed for haplotype reconstruction and phased variant identification. We further show that variants obtained from the haplotype-aware genotyping pipeline can be heuristically ranked to focus on potential pathogenic candidates without a priori knowledge of the disease-causing variants. Moreover, consideration of the variants unique to targeted long-read sequencing that are not covered by short-read technology demonstrated higher precision and F1 scores for variant discovery by long-read sequencing. This work establishes that targeted adaptive long-read sequencing can generate targeted, chromosome-phased data sets for identification of coding and non-coding disease-causing alleles in IRDs and can be applicable to other Mendelian diseases.

Targeted long-read sequencing allows for rapid identification of pathogenic disease-causing variants in retinoblastoma

BACKGROUND

Identification of disease-causing variants of the retinoblastoma gene (RB1), the predominant cause of retinoblastoma, is challenging. Targeted long-read genome sequencing offers a novel approach to resolve the diverse range of pathogenic variants in RB1 and provides haplotype information rapidly.

MATERIALS AND METHODS

Genomic DNA was isolated from a venipuncture blood draw of a retinoblastoma patient. Whole genome sequencing (WGS) was carried out using the short-read Ilumina platform. WGS and targeted sequencing of RB1 was accomplished using the long-read Oxford Nanopore Technologies (ONT) platform. Deep-learning frameworks allowed haplotagging, variant calling, and variant annotation of both short- and long-read data.

RESULTS

Targeted long-read sequencing of the RB1 gene allowed for enhanced depth of read coverage for discovery of rare variants and haplotype analysis. A duplication leading to a frameshift and early termination in RB1 was identified as the most deleterious variant by all sequencing methods, with long-read technology providing additional information of methylation signal and haplotype information. More importantly, there was greater than 98% concordance of RB1 variants identified between short-read and targeted long-read sequencing modalities.

CONCLUSIONS

Targeted long-read technology allows for focused sequencing effort for variant discovery. Application of this for the first time in a retinoblastoma patient allowed haplotagged variant identification and demonstrated excellent concordance with benchmark short-read sequencing. The added benefit of targeted long-read sequencing to resolve disease-causing genomic variation in RB1 rapidly from a blood draw will provide a more definitive diagnosis of heritable RB and guide management decisions for patients and their families.

Machine Learning Prediction of Adenovirus D8 Conjunctivitis Complications From Viral Whole-Genome Sequence

Objective

To obtain complete DNA sequences of adenoviral (AdV) D8 genome from patients with conjunctivitis and determine the relation of sequence variation to clinical outcomes.

Design

This study is a post hoc analysis of banked conjunctival swab samples from the BAYnovation Study, a previously conducted, randomized controlled clinical trial for AdV conjunctivitis.

Participants

Ninety-six patients with AdV D8-positive conjunctivitis who received placebo treatment in the BAYnovation Study were included in the study.

Methods

DNA from conjunctival swabs was purified and subjected to whole-genome viral DNA sequencing. Adenovirus D8 variants were identified and correlated with clinical outcomes, including 2 machine learning methods.

Main Outcome Measures

Viral DNA sequence and development of subepithelial infiltrates (SEIs) were the main outcome measures.

Results

From initial sequencing of 80 AdV D8-positive samples, full adenoviral genome reconstructions were obtained for 71. A total of 630 single-nucleotide variants were identified, including 156 missense mutations. Sequence clustering revealed 3 previously unappreciated viral clades within the AdV D8 type. The likelihood of SEI development differed significantly between clades, ranging from 83% for Clade 1 to 46% for Clade 3. Genome-wide analysis of viral single-nucleotide polymorphisms failed to identify single-gene determinants of outcome. Two machine learning models were independently trained to predict clinical outcome using polymorphic sequences. Both machine learning models correctly predicted development of SEI outcomes in a newly sequenced validation set of 16 cases (P = 1.5 × 10^-5). Prediction was dependent on ensemble groups of polymorphisms across multiple genes.

Conclusions

Adenovirus D8 has ≥ 3 prevalent molecular substrains, which differ in propensity to result in SEIs. Development of SEIs can be accurately predicted from knowledge of full viral sequence. These results suggest that development of SEIs in AdV D8 conjunctivitis is largely attributable to pathologic viral sequence variants within the D8 type and establishes machine learning paradigms as a powerful technique for understanding viral pathogenicity.

Deep Metagenomic Sequencing for Endophthalmitis Pathogen Detection Using a Nanopore Platform

PURPOSE

To evaluate the utility of nanopore sequencing for identifying potential causative pathogens in endophthalmitis, comparing culture results against full-length 16S rRNA nanopore sequencing (16S Nanopore), whole genome nanopore sequencing (Nanopore WGS), and Illumina (Illumina WGS).

DESIGN

Cross-sectional diagnostic comparison.

METHODS

Patients with clinically suspected endophthalmitis underwent intraocular vitreous biopsy as per standard care. Clinical samples were cultured by conventional methods, together with full-length 16S rRNA and WGS using nanopore and Illumina sequencing platforms.

RESULTS

Of 23 patients (median age 68.5 years [range 47-88]; 14 males [61%]), 18 cases were culture-positive. Nanopore sequencing identified the same cultured organism in all of the culture-positive cases and identified potential pathogens in two culture-negative cases (40%). Nanopore WGS was able to additionally detect the presence of bacteriophages in three samples. The agreements at genus level between culture and 16S Nanopore, Nanopore WGS, and Illumina WGS were 75%, 100%, and 78%, respectively.

CONCLUSIONS

Whole genome sequencing has higher sensitivity and provides a viable alternative to culture and 16S sequencing for detecting potential pathogens in endophthalmitis. Moreover, WGS has the ability to detect other potential pathogens in culture-negative cases. Whilst Nanopore and Illumina WGS provide comparable data, nanopore sequencing provides potential for cost-effective point-of-care diagnostics.

Molecular and Clinical Characterization of Human Adenovirus E4-Associated Conjunctivitis

PURPOSE

To determine the characteristics of conjunctivitis associated with human adenovirus E4 (AdV E4).

METHODS

Samples and outcomes from 500 patients with conjunctivitis were obtained from the NVC-422 randomized controlled clinical trial comparing auriclosene to placebo. Molecular typing identified 36 cases associated with AdV E4. Signs and symptoms at presentation and at the day 18 endpoint were compared with the larger cohort of 262 subjects with conjunctivitis caused by due to AdV D8. Full viral genomes of 22 AdV E4 isolates were reconstructed.

RESULTS

AdV E4 was the most frequently identified adenoviral type in conjunctivitis cases from the United States. Signs and symptoms at presentation were comparable to those associated with AdV D8. Viral load at presentation was comparable between groups but resolution was more rapid in the AdV E4 group. Clinical signs were fully resolved by day 18 in 26 of 36 (72%) patients with AdV E4. Subepithelial infiltrates developed in 12 of 36 (33%) patients with AdV E4 compared with 98 of 215 (45%) patients with AdV D8 (P = .0001). One hundred twenty-four polymorphisms were observed among 22 whole viral genome sequences, which clustered into 3 clades. Patients in each clade developed subepithelial infiltrates. Neither single nucleotide polymorphism analysis nor machine learning approaches identified specific sequence features predictive of presenting signs or outcome.

CONCLUSIONS

AdV E4 conjunctivitis may be indistinguishable at presentation from AdV D8-associated disease. Resolution of viral load for AdV E4 appears more rapid than for AdV D8, and the risk for subepithelial infiltrates appears lower. Multiple substrains of AdV E4 are in circulation but all appeared equivalently pathogenic for conjunctivitis. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Hospitalization and mortality associated with SARS-CoV-2 viral clades in COVID-19

The COVID-19 epidemic of 2019-20 is due to the novel coronavirus SARS-CoV-2. Following first case description in December, 2019 this virus has infected over 10 million individuals and resulted in at least 500,000 deaths world-wide. The virus is undergoing rapid mutation, with two major clades of sequence variants emerging. This study sought to determine whether SARS-CoV-2 sequence variants are associated with differing outcomes among COVID-19 patients in a single medical system. Whole genome SARS-CoV-2 RNA sequence was obtained from isolates collected from patients registered in the University of Washington Medicine health system between March 1 and April 15, 2020. Demographic and baseline clinical characteristics of patients and their outcome data including their hospitalization and death were collected. Statistical and machine learning models were applied to determine if viral genetic variants were associated with specific outcomes of hospitalization or death. Full length SARS-CoV-2 sequence was obtained 190 subjects with clinical outcome data. 35 (18.4%) were hospitalized and 14 (7.4%) died from complications of infection. A total of 289 single nucleotide variants were identified. Clustering methods demonstrated two major viral clades, which could be readily distinguished by 12 polymorphisms in 5 genes. A trend toward higher rates of hospitalization of patients with Clade 2 infections was observed (p = 0.06, Fisher's exact). Machine learning models utilizing patient demographics and co-morbidities achieved area-under-the-curve (AUC) values of 0.93 for predicting hospitalization. Addition of viral clade or sequence information did not significantly improve models for outcome prediction. In summary, SARS-CoV-2 shows substantial sequence diversity in a community-based sample. Two dominant clades of virus are in circulation. Among patients sufficiently ill to warrant testing for virus, no significant difference in outcomes of hospitalization or death could be discerned between clades in this sample. Major risk factors for hospitalization and death for either major clade of virus include patient age and comorbid conditions.

Outcomes associated with SARS-CoV-2 viral clades in COVID-19

Background The COVID-19 epidemic of 2019-20 is due to the novel coronavirus SARS-CoV-2. Following first case description in December, 2019 this virus has infected over 10 million individuals and resulted in at least 500,000 deaths world-wide. The virus is undergoing rapid mutation, with two major clades of sequence variants emerging. This study sought to determine whether SARS-CoV-2 sequence variants are associated with differing outcomes among COVID-19 patients in a single medical system. Methods Whole genome SARS-CoV-2 RNA sequence was obtained from isolates collected from patients registered in the University of Washington Medicine health system between March 1 and April 15, 2020. Demographic and baseline medical data along with outcomes of hospitalization and death were collected. Statistical and machine learning models were applied to determine if viral genetic variants were associated with specific outcomes of hospitalization or death. Findings Full length SARS-CoV-2 sequence was obtained 190 subjects with clinical outcome data. 35 (18.4%) were hospitalized and 14 (7.4%) died from complications of infection. A total of 289 single nucleotide variants were identified. Clustering methods demonstrated two major viral clades, which could be readily distinguished by 12 polymorphisms in 5 genes. A trend toward higher rates of hospitalization of patients with Clade 2 was observed (p=0.06). Machine learning models utilizing patient demographics and co-morbidities achieved area-under-the-curve (AUC) values of 0.93 for predicting hospitalization. Addition of viral clade or sequence information did not significantly improve models for outcome prediction. Conclusion SARS-CoV-2 shows substantial sequence diversity in a community-based sample. Two dominant clades of virus are in circulation. Among patients sufficiently ill to warrant testing for virus, no significant difference in outcomes of hospitalization or death could be discerned between clades in this sample. Major risk factors for hospitalization and death for either major clade of virus include patient age and comorbid conditions.

Prognostic Utility of Whole-Genome Sequencing and Polymerase Chain Reaction Tests of Ocular Fluids in Postprocedural Endophthalmitis

PURPOSE

To associate detection of potential pathogen DNA in endophthalmitis with clinical outcomes.

DESIGN

Prospective cohort study.

METHODS

Patients in whom endophthalmitis was diagnosed following an intraocular procedure were recruited. Clinical outcome data from baseline, week-1, month-1, and month-3 visits were collected. Intraocular biopsy samples were cultured by standard methods. Quantitative polymerase chain reaction (qPCR) was performed for specific pathogens and whole-genome sequencing (WGS).

RESULTS

A total of 50 patients (mean age 72 years old; 52% male) were enrolled. Twenty-four cases were culture-positive and 26 were culture-negative. WGS identified the cultured organism in 76% of culture-positive cases and identified potential pathogens in 33% of culture-negative cases. Month-1 and -3 visual acuities did not vary by pathogen-positive versus pathogen-negative cases as detected by either culture or WGS. Visual outcomes of Staphylococcus epidermidis endophthalmitis were no different than those of pathogen-negative cases, whereas the patients infected with other pathogens showed worse outcome. Higher baseline bacterial DNA loads of bacteria other than those of S epidermidis detected by WGS were associated with worse month-1 and -3 visual acuity, whereas the S epidermidis loads did not appear to influence outcomes. Torque teno virus (TTV) and Merkel cell polyomavirus (MCV) were detected by qPCR in 49% and 19% of cases, respectively. Presence of TTV at presentation was associated with a higher rate of secondary pars plana vitrectomy (P = .009) and retinal detachment (P = .022).

CONCLUSIONS

The presence and higher load of bacteria other than S epidermidis detected by WGS or DNA from TTV by qPCR in ocular fluids is associated with worse outcomes in post-procedure endophthalmitis.

In vivo pharmacological characterization of AC-3933, a benzodiazepine receptor partial inverse agonist for the treatment of Alzheimer's disease

GABAergic neurons are known to inhibit neural transduction and therefore negatively affect excitatory neural circuits in the brain. We have previously reported that 5-(3-methoxyphenyl)-3-(5-methyl-1,2,4-oxadiazol-3-yl)-1,6-naphthyridin-2(1H)-one (AC-3933), a partial inverse agonist for the benzodiazepine receptor (BzR), reverses GABAergic inhibitory effect on cholinergic neurons, and thus enhances acetylcholine release from these neurons in rat hippocampal slices. In this study, we evaluated AC-3933 potential for the treatment of Alzheimer's disease, a disorder characterized by progressive decline mainly in cholinergic function. Oral administration of AC-3933 (0.01-0.03mg/kg) resulted in the amelioration of scopolamine-induced amnesia, as well as a shift in electroencephalogram (EEG) relative power characteristic of pro-cognitive cholinergic activators, such as donepezil. In addition, treatment with AC-3933 even at the high dose of 100mg/kg p.o. produced no seizure or anxiety, two major adverse effects of BzR inverse agonists developed in the past. These findings indicate that AC-3933 with its low risk for side effects may be useful in the treatment of Alzheimer's disease.

Cell-phone based assistance for waterworks/sewage plant maintenance

Cell-phones are now incorporating the functions necessary for them to be used as mobile IT devices. In this paper, we present our results of the evaluation of cell-phones as the mobile IT device to assist workers in industrial plants. We use waterworks and sewage plants as examples. By employing techniques to squeeze the SCADA screen on CRT into a small cell-phone LCD, we have made it easier for a plant's field workers to access the information needed for effective maintenance, regardless of location. An idea to link SCADA information and the plant facility information on the cell-phone is also presented. Should an accident or emergency situation arise, these cell-phone-based IT systems can efficiently deliver the latest plant information, thus the worker out in the field can respond to and resolve the emergency.

Ganglion-associated ulnar tunnel syndrome treated by ultrasonographically assisted aspiration and splinting

We describe a case of ulnar nerve compression at the wrist due to a ganglion. This was treated by aspiration of the ganglion under ultrasonography and splinting because the patient was pregnant. The ulnar nerve palsy resolved completely and the ganglion disappeared. A follow-up ultrasonographic examination after 2 years showed no recurrence of the ganglion.

Development of ossification of the posterior longitudinal ligament of the cervical spine after atlanto-axial fusion

We report three cases of the development of ossification of the posterior longitudinal ligament (OPLL) after atlanto-axial fusion. This fusion should be recognized as a causative factor in the development of OPLL. The pathological mechanism is suggested to be increased mechanical stress.

One-portal technique of endoscopic fasciotomy: Chronic compartment syndrome of the lower leg

Many athletes complain of exercise-induced pain in the lower leg that can be caused by inflammatory diseases, peripheral nervous system disease, fatigue fracture, shin splint, and chronic compartment syndrome (CCS). CCS is the most typical exercise-induced condition and it often requires surgical decompression of the several compartments. There are already many techniques reported in the literature. Recently, an endoscopic technique for CCS was reported with which excellent results were achieved. We have modified it and developed a new technique for treating CCS of the lower leg. We report a case of CCS of the lower leg treated with 1-portal endoscopic fasciotomy. The technique helps to decrease damage to soft tissue and patients will immediately return to normal activities of daily living.

Defective infection of bovine herpesvirus 1 in non-permissive murine cells

The defective growth of bovine herpesvirus I (BHV-1) was analyzed in non-permissive murine embryo fibroblast, BALB/3T3 A31-1-1 (A31) cells. BHV-1 was able to attach and penetrate into A31 cells at similar levels that were seen in semi-permissive cells. Once penetrated into A31 cells, BHV-1 was efficiently transported to nuclei, but the onset of expression of immediate early (IE) protein and viral DNA replication was not observed. These data suggest that the viral replication of BHV-1 in A31 cells is arrested at the point prior to the expression of IE proteins.

Evaluation of a floating dosage form of nicardipine hydrochloride and hydroxypropylmethylcellulose acetate succinate prepared using a twin-screw extruder

A floating dosage form composed of nicardipine hydrochloride (NH) and hydroxypropylmethylcellulose acetate succinate (enteric polymer) was prepared using a twin-screw extruder. By adjusting the position of the high-pressure screw elements in the immediate vicinity of die outlet, and by controlling the barrel temperature, we were able to prepare a puffed dosage form with very small and uniform pores. It was found that the porosity and pore diameter could be controlled by the varying amount of calcium phosphate dihydrate. In the shaking test, the puffed dosage form was found to have excellent floating ability and mechanical strength in acid solution (JP First Fluid, pH 1.2). The dissolution profile of NH was controlled by the amount of wheat starch. In the dissolution test using JP Second Fluid (pH 6.8), rapid dissolution of NH and loss of buoyancy were observed. It was shown that the puffed dosage form, consisting of enteric polymer prepared using the twin-screw extruder, was very useful as a floating dosage form that was retained for a long period in the stomach.

Attachment and penetration properties of bovine herpesvirus 1 recombinants expressing pseudorabies virus glycoproteins gC and gB

OBJECTIVE

Bovine herpesvirus 1 (BHV-1) has a relatively narrow host cell range in vitro and in vivo when compared to pseudorabies virus (PrV). The aim of this study was to elucidate whether homologous glycoproteins gC and gB from PrV can function in a heterologous BHV-1 background and whether the expression of these PrV glycoproteins influences the in vitro host cell specificity of BHV-1.

METHODS

We constructed BHV-1 recombinants in which PrV gC and gB were expressed either individually or in combination, and examined their attachment and penetration properties in permissive Madin-Darby bovine kidney (MDBK), semipermissive hamster lung (HmLu-1) and nonpermissive murine embryo fibroblast (A31) cells.

RESULTS

Two BHV-1 recombinants which expressed PrV gC exhibited remarkable competence in virus attachment to cells. The expression of PrV gB improved the virus attachment only a little but penetration, especially into HmLu-1 and A31 cells, was enhanced.

CONCLUSIONS

These results indicate that PrV gC and gB can function in a BHV-1 environment and facilitate virus attachment and penetration by BHV-1.

Bovine herpesvirus 1 glycoprotein G is required for prevention of apoptosis and efficient viral growth in rabbit kidney cells

In rabbit kidney (RK13) cells, gG-negative BHV-1 exhibited significant defects in plaque formation and growth compared to that of gG-positive BHV-1. RK13 cells infected with gG-negative BHV-1 exhibited a distinctive CPE and contained a larger number of cells stained with trypan blue dye compared to those infected with gG-positive strains, suggesting that gG-negative BHV-1 inflicted more damage to the infected cells than gG-positive BHV-1. Apoptotic cell death was induced in RK13 cells infected with gG-negative BHV-1 within 8 h. In contrast, the onset of apoptosis in gG-positive BHV-1-infected RK13 cells was around 12-16 h postinfection. In the presence of caspase inhibitor Z-Asp-CH2-DCB, multiplication of gG-negative minus BHV-1 was significantly increased. These results demonstrate that BHV-1 gG is involved in stabilizing the cell structure, postponing apoptotic process, and efficient BHV-1 replication in infected RK13 cells.

Ultrasonography in the diagnosis of ulnar tunnel syndrome caused by an occult ganglion

We report a case of ulnar tunnel syndrome caused by an occult ganglion which was diagnosed preoperatively by ultrasonography.

Median nerve compression by a radially inserted palmaris longus tendon after release of the antebrachial fascia: A complication of carpal tunnel release

We describe a case that had recurrent median nerve compression after release of the antebrachial fascia in carpal tunnel release. The nerve was compressed by a palmaris longus tendon that was inserted radially into the thenar fascia. After decompression (detachment of the tendon) the patient had symptom relief. Release of the antebrachial fascia in the presence of this tendon variant carries a risk of median nerve compression by the tendon.

Attachment and penetration of canine herpesvirus 1 in non-permissive cells

Canine herpesvirus 1 (CHV-1) has a relatively narrow host cell range when compared to other alphaherpesviruses. The early events of CHV-1 infection in a permissive Madin-Darby canine kidney (MDCK) and non-permissive cell lines. In order to quantify attachment and penetration, were investigated quantitative competitive PCR (QCPCR) method was established for quantitation of CHV-1 DNA. In all non-permissive cells tested, no significant decrease in viral attachment was observed. When CHV-1 was treated with heparin, viral attachment to MDCK cells was reduced by 25% of the input CHV-1 attached to MDCK cells even in the presence of 50 microg/ml heparin. However, the attachment of CHV-1 to non-permissive cells was severely impaired by heparin treatment. In permissive MDCK cells, about 80% of attached CHV-1 penetrated into cells. However, only 4-10% of CHV-1 attached to non-permissive cells penetrated into cells. Our data indicated that CHV-1, like other herpesviruses, attached to permissive MDCK cells through two mechanisms: the first one is through the interaction mediated by heparan sulfate (HS) on the cell surface and the second involves unidentified viral component and the cellular receptor. In contrast, the non-permissive cells lacked the cellular receptor for the second attachment mechanism and the defect in viral penetration into non-permissive cell might be related to the lack of the cellular receptor.

Bovine herpesvirus 1 glycoprotein G is required for viral growth by cell-to-cell infection

The bovine herpesvirus 1 (BHV-1) US4 gene encodes glycoprotein G (gG), which is conserved in the majority of alphaherpesviruses. In order to identify the role of BHV-1 gG in the viral infection cycle, a gG minus BHV-1 mutant and its gG-positive revertant were constructed and their growth characteristics in Madin-Darby bovine kidney (MDBK) cells were compared. The gG minus mutant formed smaller plaques than the gG-positive BHV-1 in MDBK cells. When a monolayer culture of MDBK cells was infected with BHV-1 at a low multiplicity of infection and overlaid with semi-solid growth medium, under which adsorption of the mature virion released in the medium was inhibited, gG-positive BHV-1 multiplied, while the growth of the gG negative BHV-1 was severely inhibited. These data suggest that BHV-1 gG functions in direct cell-to-cell transmission mechanism of BHV-1 in tissue culture.

Insufficiency fracture of the femoral neck after intramedullary nailing

We report a patient with insufficiency fracture that occurred after intramedullary nailing for a subtrochanteric fracture. Intramedullary nailing is speculated to have increased the stress in the already osteoporotic subcapital region. It therefore should be recognized as a causative factor in insufficiency fracture of the femoral neck. Careful follow-up is needed for patients with this condition.

Histology of the transverse carpal ligament and flexor tenosynovium in idiopathic carpal tunnel syndrome

Histology of the transverse carpal ligament and flexor tenosynovium was investigated in 166 wrists from 130 patients with idiopathic carpal tunnel syndrome. Nine wrists from 9 controls were used for comparison. In the patients, 73.5% of the ligament and 56.0% of the tenosynovium showed normal histology. In the remaining specimens, the ligament showed mucoid change (17.5%), amyloid deposits (7.8%), inflammation (3.0%), and chondrometaplasia (2.4%), and the tenosynovium showed fibrosis (25.3%), edema (7.2%), inflammation (10.2%), amyloid deposits (8.4%), and vascular hypertrophy (4.8%). The majority of these changes were mild in degree and the pathophysiology did not appear to be meaningful. We conclude that in idiopathic carpal tunnel syndrome, the ligament and tenosynovium often show normal histology and there are no typical or consistent changes with which idiopathic carpal tunnel syndrome can be associated.

Iatrogenic injury of the spinal accessory nerve. Results of repair

We reviewed the results of repair of the spinal accessory nerve in seven patients seen between September 1994 and January 1996. The nerve had been injured during biopsy of a cervical lymph node in six patients and during removal of a bullet in one. The average interval between the time of the injury and the repair of the nerve was eight months (range, three to fourteen months). An end-to-end repair of the nerve was performed in six patients, and a neurolysis was done in one. The average duration of follow-up was thirty-two months (range, twenty-four to thirty-nine months). Postoperatively, all seven patients had relief of pain and stiffness in the shoulder girdle. Manual muscle-testing revealed normal strength of the trapezius, which was comparable with that on the unaffected side. Four patients regained normal function of the shoulder. Three patients reported a stretching sensation or discomfort in the neck, periscapular discomfort, and fatigue of the extremity when lifting heavy objects or performing overhead activities. However, these residual symptoms were mild and tolerable and thus were different in nature from the preoperative pain and stiffness. Iatrogenic injury of the spinal accessory nerve should be suspected if a patient has pain or stiffness in the shoulder girdle and a history of a recent operation on the neck. The nerve should be explored if spontaneous recovery does not occur.

Distance between the median nerve and ulnar neurovascular bundle: clinical significance with ultrasonographically assisted carpal tunnel release

In ultrasonographically assisted carpal tunnel release, the zone of the transverse carpal ligament between the median nerve and ulnar neurovascular bundle is of significance because proximity of the cutting device to these structures depends on its width. In this study, we measured the width of the zone at 5 levels in 60 wrists from 54 patients with surgery-indicated idiopathic carpal tunnel syndrome. The width of the 5 levels ranged from 2.8 to 11.2 mm (mean, 7.1 mm) at the hook of the hamate, 3.0 to 12.5 mm (mean, 7.9 mm) at the distal one fourth of the carpal tunnel, 2.8 to 12.4 mm (mean, 8.0 mm) at the midsection of the tunnel, 1.5 to 13.0 mm (mean, 7.4 mm) at the proximal one fourth of the tunnel, and 5.3 to 17.2 mm (mean, 10.2 mm) at the wrist crease. These widths were not significantly correlated with radiographic measurements of the hand (cord of the radiocarpal joint arc, carpal height, third metacarpal, and hand length). We conclude that there is considerable variation of the width among individuals. Based on our clinical experience (3 wrists of 3 patients in this study), patients with a width of < or =3 mm at any level should be screened out preoperatively by wrist imaging. Our findings also may be of use to surgeons performing endoscopic carpal tunnel release.

Intraneural ganglion of the branchial plexus

We report a case of an intraneural ganglion of the brachial plexus. Excision relieved the symptoms.

Ultrasonographically assisted carpal tunnel release

An operative technique of carpal tunnel release using intraoperative ultrasonography is described. In this technique, "safe line" is defined in the transverse carpal ligament and the adjacent deep forearm fascia midway between the ulnar margin of the median nerve and the radial margin of the ulnar artery. After ultrasonographic design of a 1.0 to 1.5-cm skin incision along the safe line at the distal carpal tunnel, the distal ligament is released under direct vision. Proximal release is performed along this line under ultrasonographic monitoring using a device that consists of a basket punch and an outer metal tube. In a prospective randomized study, the outcomes were compared for carpal tunnel release using either this technique in 50 hands of 50 patients or conventional open release in 53 hands of 53 patients. Follow-up assessment at 3, 6, 13, 26, 52, and 104 weeks showed no significant difference with respect to numbness and paresthesias, static two-point discrimination, findings on Semmes-Weinstein monofilament testing, findings on manual muscle testing of the abductor pollicis brevis, and electrophysiologic findings. The ultrasonographic-release group had better outcomes regarding pain, tenderness of the scar, and key-pinch strength at 3, 6, and 13 weeks, and grip strength at 3 and 6 weeks after surgery. The scar was more aesthetic in this group. There were no complications with either technique.

[Autosomal dominant distal myopathy with rimmed vacuoles and cytoplasmic inclusions: report of a family]

We reported four patients with distal myopathy in the same family. Muscle weakness and atrophy started in the lower extremities, especially in the calf muscle, and it extended to the upper extremities and pelvic muscles to a variable extent. Facial and bulbar muscles were slightly involved in one case. The anterior tibial muscle tended to be better preserved than the calf muscle. Cardiac abnormalities were absent in any case. Serum creatine kinase activity was normal or mildly elevated. Skeletal muscle biopsies revealed myopathic process presenting rimmed vacuoles, eosinophilic cytoplasmic inclusions and/or subsarcolemmal mass. Ultrastructurally, cytoplasmic inclusions were composed of electron dense granular material and intermediate-sized filaments. There were membranous whorls and myelin-like figures which were the characteristic findings of rimmed vacuoles. Immunohistochemistry revealed accumulation of desmin, dystrophin and vimentin in the cytoplasm of degenerating muscle fibers and in the inclusion. In present patients, cardiac function was normal and the tibialis anterior muscle was relatively spared. These features were different from the autosomal dominant rimmed-vacuolar myopathy with desmin storage described in previous reports.

Osteoid osteoma of the radial diaphysis

We report a case of osteoid osteoma of the radial diaphysis. Excision of the nidus relieved pain.

Cubital tunnel syndrome caused by tophaceous gout

We report a case of cubital tunnel syndrome caused by tophaceous gout. The ulnar nerve was compressed by a tophus at the distal cubital tunnel. Surgical decompression relieved the symptoms.

Restricted motion of the median nerve in carpal tunnel syndrome

Motion of the median nerve was compared on an axial ultrasonographic image in the mid-carpal tunnel in 30 wrists of 15 women with bilateral idiopathic carpal tunnel syndrome and 30 wrists of 15 healthy women. During passive flexion and extension of the index finger, the control wrists had transverse sliding of the nerve beneath the flexor retinaculum (1.75 +/- 0.49 mm), which was regarded as a physiological phenomenon. In contrast, the wrists of patients with carpal tunnel syndrome had significantly less sliding (0.37 +/- 0.34 mm; P = 0.0001), which indicates that physiological motion of the nerve is restricted. This decrease in nerve mobility may be of significance in the pathophysiology of carpal tunnel syndrome.

Closed rupture of the flexor digitorum profundus tendon within the carpal tunnel

We report a case of a closed rupture within the carpal tunnel of the flexor digitorum profundus tendon of the little finger. There was no underlying pathology.

Unilateral carpal tunnel syndrome and space-occupying lesions

To assess the association between unilateral carpal tunnel syndrome and space-occupying lesions, 128 patients have been reviewed. They were divided into bilateral, subclinical (unilateral signs and symptoms, and bilateral slowing in the median nerve conduction) and unilateral carpal tunnel syndrome. Space-occupying lesions were investigated on the basis of physical examination and wrist imaging using plain radiographs and ultrasonograms. Of 20 patients with unilateral carpal tunnel syndrome, space-occupying lesions were found in seven (occult ganglion in five and occult calcified mass in two). In contrast, none of 89 patients with bilateral carpal tunnel syndrome and 19 with subclinical carpal tunnel syndrome had space-occupying lesions. We conclude that careful examination and wrist imaging on suspicion of local pathology, especially a space-occupying lesion, are needed when the condition is unilateral and the aetiology is not clear from the history and on physical examination.

Ultrasonography in the diagnosis of carpal tunnel syndrome caused by an occult ganglion

A case is reported of carpal tunnel syndrome caused by an occult ganglion which was diagnosed preoperatively by ultrasonography.

The use of ultrasonography in detection of synovitis in carpal tunnel syndrome

The findings of pre-operative ultrasonography of the carpal tunnel were compared with synovial histology in 50 surgically treated wrists with carpal tunnel syndrome. Eight wrists with a massive hypoechoic area (group 3) had synovitis. 28 with a minimal hypoechoic area (group 1) had no evidence of inflammation. 14 with a moderately increased hypoechoic area (group 2) consisted of three with synovitis, four with lymphocytic infiltration and seven without inflammation. Group 3 strongly indicates synovitis, in which case one should consider aetiology other than the idiopathic cause. Bilateral synovial thickening suggests carpal tunnel syndrome as the initial clinical picture of rheumatoid arthritis, and group 1 indicates idiopathic carpal tunnel syndrome provided that there are no primary causes.

Synergistic suppression of the clonogenicity of U937 leukemic cells by combinations of recombinant human interleukin 4 and granulocyte colony-stimulating factor

The actions and interactions of purified recombinant human (rh) interleukin 4 (IL-4) and granulocyte colony-stimulating factor (G-CSF) on the clonogenicity of human leukemic cell line U937 were studied in vitro. Parameters analyzed were the suppression of stem cell generation using sequential clonal cultures, alterations of surface antigen expression, and morphological changes. IL-4 alone (10 U/ml) and G-CSF alone (1000 U/ml) only slightly reduced colony numbers (80% +/- 7% and 87% +/- 7% of control colonies, respectively). However, IL-4 interacted synergistically with G-CSF to further reduce the colony number (46% +/- 8% of control colonies) and suppress the self-renewal ability (clonogenicity) of U937 cells. This synergistic effect was not eliminated by cultures containing neutralizing concentrations of anti-granulocyte-macrophage colony-stimulating factor (anti-GM-CSF), anti-interleukin 6 (anti-IL-6), anti-interferon-alpha (anti-IFN-alpha), anti-IFN-gamma, anti-transforming growth factor-beta (anti-TGF-beta) serum, and anti-tumor necrosis factor-alpha (anti-TNF-alpha) serum. The coexistence of IL-4 and G-CSF was required for at least 48 h to reveal the synergistic action as assessed by preincubation and delayed addition experiments. Combinations of IL-4 and G-CSF showed a significant increase in CD11b expression on U937 cells. This action was not observed with HL60, K562, ML-1, or KG-1 leukemic cell lines, and IL-4 did not show any synergistic suppression of clonogenicity of U937 leukemic cells in combination with other cytokines tested in this study. These results suggest that IL-4 in combination with G-CSF may have some capacity to synergistically suppress human leukemic cells of specific types with loss of clonogenicity.

Transverse sliding of the median nerve beneath the flexor retinaculum

Transverse sliding of the median nerve beneath the flexor retinaculum during active-resistant flexion of the fingers was sonographically demonstrated. Although it is a physiological phenomenon, it may cause mechanical nerve deformation in addition to longitudinal sliding when the nerve is subject to compression against the flexor retinaculum by tensed overlying flexor tendons.

Different distribution of endothelin receptor subtypes in pulmonary tissues revealed by the novel selective ligands BQ-123 and [Ala1,3,11,15]ET-1

We have demonstrated the different distribution of two distinct endothelin (ET) receptor subtypes in porcine pulmonary tissues using a radioligand binding assay. The clear differentiation of the subtypes was made possible by the discovery of two compounds, BQ-123 and [Ala1,3,11,15]ET-1 (4AlaET-1), that are highly selective for ETA and ETB receptors, respectively. In the bronchus and lung parenchyma, BQ-123 inhibited 65% and 30% of [125I]ET-1 binding on the sensitive sites, while 4AlaET-1 displaced 25% and 60%, respectively. The combination of the two compounds completely inhibited ET-1 binding in both tissues. An autoradiographic study of [125I]ET-1 binding using BQ-123 and 4AlaET-1 also supported the different localization of two ET receptor subtypes in pulmonary tissues. In particular, the blood vessels and bronchi are rich in ETA, but the lung parenchyma is rich in ETB.

Alteration of cell-associated heparan sulfate proteoglycan in tumor-bearing rats

Alteration of cell-associated heparan sulfate proteoglycan (HSPG) under tumor-bearing conditions was evaluated using microsomal membranes prepared from the liver of ascites Tawa sarcoma-bearing and age-matched control rats. Cell-associated HSPGs have been fractionated into two populations displaying different modes of membrane association; one is a NaCl-soluble HSPG and the other is recovered only after detergent treatment of the membranes. The former is thought to represent HSPG from the peripheral membrane and the latter, HSPG from the intercalated membrane. We extracted the cell-associated HSPGs from liver microsomal membranes with a NaCl solution followed by a deoxycholate (DCA) solution. Both were isolated by gel filtration and cetylpyridinium chloride precipitation. Glycosaminoglycans (GAGs) were isolated from the tumor cells and tumorous ascitic fluids by standard procedures. Using electrophoresis on a cellulose acetate membrane, it was confirmed that the cell-associated HSPGs contained no GAG chains other than HS, and that these HSPGs did not include PGs from tumor cells since hyaluronic acid predominates in tumor cells while chondroitin sulfate is present in ascitic fluids. The HSPG extracted with the DCA solution was markedly reduced under tumor-bearing conditions, with slight increase in the NaCl-soluble HSPG. The results suggests that this condition strongly influences the type of cell-associated HSPG related to the intracellular cytoskeleton.

Hereditary transmission of tetralogy of Fallot, cardiac hypertrophy, and anomalies of great vessels in WKY/NCrj rats

We examined 78 fetuses on d 21 of gestation (G21) and 83 neonates on d 2 after birth (A2), which were first generation offspring of WKY rats mated with normal Wistar rats (F1). In addition, we examined six groups of fetuses on d 19 of gestation (G19): 65 Wistar rats, 111 WKY rats, 85 F1, 100 F1 X F1, 92 F1 X Wistar, and 97 F1 X WKY progeny. In the F1 at G19, G21, and A2, there were abnormalities of the pulmonary valve, pulmonary outflow tract, architecture of muscle bundle, and pulmonary arterial branch, as well as hypoplastic ductus arteriosus and postnatal cardiac hypertrophy, similarly in males and females but at a lower incidence and to a lesser extent than in the WKY rats. Severe pulmonary valve dysplasia and ventricular septal defect with overriding of the aorta (tetralogy of Fallot), usually associated with a markedly small ductus, were not present or were very rare in the F1 and the F1 X Wistar but were present in the F1 X WKY and in the F1 X F1 less prevalently than in the WKY. The size of the ductus showed a continuous distribution in all of the six groups; there was a large skewing toward lower values in the WKY, the F1 X WKY, and the F1 X F1. These results suggest that cardiovascular anomalies of WKY rats are transmitted as autosomal recessive or incomplete autosomal dominant traits with an incomplete penetrance and variable expressivity or as polygenic traits. Chromosomal analysis of 31 WKY fetuses revealed no aberrations specifically related to the development of cardiovascular malformations.

Radial nerve entrapment by the lateral head of the triceps

A case of slowly progressive radial nerve entrapment of spontaneous onset is presented. Surgical exploration revealed compression of the radial nerve by a musculotendinous arch of the lateral head of the triceps. Relief of signs and symptoms did not ensue.

Two endothelin receptor subtypes in porcine arteries

Endothelin-1 (ET-1) and ET-3 caused constrictions of endothelium-denuded porcine coronary artery strips with different concentration-response curves: a typical sigmoidal curve to ET-1 and a two-phase sigmoidal curve to ET-3. Binding assays using a membrane preparation demonstrated different Bmax values for [125I]ET-1 and [125I]ET-3 binding. In addition, [125I]ET-1 binding was inhibited by ET-1 and ET-3 with different potencies (ET-1 greater than ET-3), while [125I]ET-3 binding was inhibited by both ETs equally. From these results, two distinct ET receptor subtypes were proposed in the artery; site 1 (selective to ET-1) and site 2 (equally sensitive to both ETs). However, only site 1 was identified on cultured arterial smooth muscle cells (VSMCs) by the binding assay, and this was confirmed since only ET-1 (not ET-3) caused a significant increase in the intracellular free Ca2+ concentration. Therefore, it seems likely that vasoconstriction is mediated via the binding of ET-1 to site 1 (VSMCs) and site 2 (non-VSMCs), or the binding of ET-3 to site 2 (non-VSMCs). Furthermore, site 2 was predominant in nonvascular tissues such as lung, kidney, and cerebellum, thereby suggesting that site 1 may exist in limited tissues such as VSMCs.