Right atrial myxoma mistaken for recurrent pulmonary thromboembolism

A 69 year old man was admitted for investigation of right sided pleuritic chest pain and dyspnoea, both of which began suddenly four days before admission. Acute pulmonary embolism was diagnosed. Six months after discharge while on warfarin he died. Necropsy found a 50 mm diameter myxoid tumour arising on the right atrial side of the interatrial septum. This lesion may have been discovered earlier by echocardiography although there were no clear indications for this investigation. Presentation was that of recurrent pulmonary embolism with no obvious source or cause of thrombosis. Patients who are thought to have idiopathic pulmonary embolism should undergo early echocardiography to exclude the rare but treatable diseases of the right heart that may be responsible

Keywords: atrial myxoma     

Everyday memory following traumatic brain injury

Residual memory deficits may represent a problem to the everyday functioning of a large number of people, including those who have sustained traumatic brain injury (TBI). The present exploratory study sought to investigate the interrelationships between subjective memory reports, performance on traditional memory tests, and performance on tests of prospective memory. These interrelationships were contrasted between a group of 24 adults who had sustained TBI and a group of 24 matched control subjects. Prospective memory was hypothesized to be indicative of everyday memory functioning. The results provided preliminary evidence that prospective memory tests are sensitive to TBIrelated neurological impairment and, in comparison to traditional tests, may be better indicators of functional memory capacity. This pattern was particularly true for control subjects, possibly because TBI subjects had difficulties in evaluating their memory functioning.     

A specific and sensitive radioimmunoassay for rat C-peptide

A sensitive and specific radioimmunoassay for rat serum C-peptide (RCP) has been developed and validated using a guinea pig anti-rat C-peptide antibody to synthetic rat C-peptide. Negligible crossreactivity (<0.01%) to human proinsulin was observed, whereas human insulin, human pancreatic polypeptide (hPP), porcine insulin, porcine C-peptide, bovine insulin, rat insulin, porcine-PP, and glucagon, respectively, did not produce measurable displacement of RCP tracer. Human C-peptide even in a supraphysiological concentration range crossreacted poorly (<0.1%). The sensitivity limit of the assay calculated at ±3 standard deviations was 24.2pM (0.07 ng/mL). RCP standard concentrations ranged from 25–1600pM. The intraassay-and between assay-coefficient of variations (CV) were 3.5–6.1% and 4.1–9.5%, respectively. The mean percentage recovery of RCP added to rat serum samples was 100.8±2%. Serum volume dilution from 25 to 100 μL did not significantly alter the expected RCP level. Migration of rat serum C-peptide and that of synthetic RCP were identical in a Sephadex G-50 chromatographic analysis. The mean fasting and postprandial plasma RCP levels in normal rats were 102±15pM and 485±75pM, respectively. RCP levels following intravenous glucose tolerance test in diabetic and nondiabetic rats were consistent with expected patterns. In conclusion, we have developed and validated a rat C-peptide assay that is sensitive, simple, and specific for RCP in serum. The assay provides a reliable tool for studies of diabetes using rodent animal models.     

Intracellular Na+ measurements in smooth muscle using SBFI – changes in [Na+], Ca2+ and force in normal and Na+-loaded ureter

 Our understanding of the control and effects of intracellular [Na⁺] ([Na⁺]_i) in intact smooth muscle is limited by the lack of data concerning [Na⁺]_i. The initial aim of this work was therefore to investigate the suitability of using the Na⁺-sensitive fluorophore SBFI in intact smooth muscle. We find this to be a good method for measuring [Na⁺]_i in ureteric smooth muscle. Resting [Na⁺]_i was found to be around 10 mM and rose to 25 mM when the Na⁺-K⁺-ATPase was inhibited by ouabain. This relatively low [Na⁺]_i in the absence of Na⁺-K⁺-ATPase suggests that other cellular processes, such as Na⁺-Ca²⁺ exchange, play a role in maintaining [Na⁺]_i under these conditions. Simultaneous measurements of [Na⁺]_i or [Ca²⁺] _i and force showed that Na⁺-Ca²⁺ exchange can play a functional role in ureteric smooth muscle. We found that the greater the driving force for Na⁺ exit and hence Ca²⁺ entry, the larger the contraction. In addition the Na⁺-Ca²⁺ exchanger activity under these conditions was found to be pH sensitive: acidification reduced the contraction and concomitant changes in [Ca²⁺] and [Na⁺]_i. We conclude that SBFI is a useful method for monitoring [Na] in smooth muscle and that Na⁺-Ca²⁺ exchange may play a functional role in the ureter. Received: 26 August 1997 / Received after revision: 27 October 1997 / Accepted: 28 October 1997     

Cloning and expression of a Streptococcus sanguis surface antigen that interacts with a human salivary agglutinin.

Human saliva contains a high-molecular-weight glycoprotein (agglutinin) which binds to specific streptococci in a calcium-dependent reaction leading to the formation of bacterial aggregates. We report the cloning of a gene encoding a surface antigen from Streptococcus sanguis M5 and show that the expressed protein inhibits agglutinin-mediated aggregation and specifically binds the salivary agglutinin in a calcium-dependent fashion. Clones isolated from the immunological screening of S. sanguis M5 genomic libraries with polyclonal antibodies against whole cells were assayed for the ability to compete with S. sanguis for agglutinin. One clone, pSSP-5, expressed antigens of 165 and 130 kilodaltons (kDa) possessing this activity. A 3-kilobase-pair (kbp) insert fragment from this clone was used to screen a genomic library in lambda EMBL3 which resulted in the isolation of clone SSP-5A. This clone contained an insert of 17 kb and expressed proteins of 170 to 205 kDa that reacted with the anti-S. sanguis antibodies. Subcloning of a 5.3-kbp EcoRI-BamHI fragment from SSP-5A produced pEB-5, which expressed streptococcal components that were indistinguishable from SSP-5A. The streptococcal antigen was purified by gel permeation and ion exchange chromatography and shown to potently compete with S. sanguis M5 cells for agglutinin. The antigen also bound purified salivary agglutinin in the presence of 1 mM CaCl2. This binding was inhibited by EDTA. Both the SSP-5 antigen and a 205-kDa protein in surface protein extracts from S. sanguis M5 cross-reacted with antibodies directed against antigen B from S. mutans and SpaA from S. sobrinus 6715. These results indicate that a 205-kDa surface protein that is antigenically related to SpaA and antigen B is involved in the binding of salivary agglutinin to S. sanguis M5.     

Immunity to vaginal reinfection in female guinea pigs infected sexually with Chlamydia of guinea pig inclusion conjunctivitis.

Guinea pig boars were inoculated intraurethrally with the chlamydial agent of guinea pig inclusion conjunctivitis (GPIC). At the heights of their urethral infections, they were caged with sows in estrus. Whereas some of the sows had not been previously exposed to GPIC agent, others had received an intravaginal inoculation 5 to 8 weeks earlier. Those sows for which infected boars provided the first exposure were challenged by intravaginal inoculation 5 to 8 weeks later. Vaginal and conjunctival scrapings were taken regularly and stained for chlamydial inclusions. Titers of serum anti-GPIC antibodies and of vaginal secretory IgA anti-GPIC antibodies were determined by immunofluorescence. Our results show for the first time that a sexually acquired vaginal GPIC infection induces immunity to manual reinfection of the vagina. Because of the high incidence of secondary conjunctival infections among the vaginally infected sows, we could not provide a sound statistical basis for our tentative conclusion that manual infection of the vagina induces immunity to sexual reinfection. The results of our antibody titrations confirm previous work showing that vaginal GPIC infection induces formation of both serum antibody and vaginal secretory immunoglobulin A antibody.     

Developmental expression of FOG-1/CPEB protein and its control in the Caenorhabditis elegans hermaphrodite germ line.

The specification of a germ cell as sperm or oocyte and determination of cell number remain unsolved questions in developmental biology. This paper examines Caenorhabditis elegans FOG-1, a CPEB-related RNA-binding protein that controls the sperm fate. We find that abundant FOG-1 protein is observed transiently in germ cells just prior to their expression of an early sperm-differentiation marker. As the germline tissue elongates, abundant FOG-1 appears more and more distally as sperm become specified, but disappears when the germ line switches to oogenesis. This dynamic pattern is controlled by both globally acting and germline-specific sex-determining regulators. Importantly, the extent of FOG-1 expression corresponds roughly to sperm number in wild-type and mutants, altering sperm number. By contrast, three other key regulators of the sperm/oocyte decision do not similarly correspond to sperm number. We suggest that FOG-1 is precisely modulated in both time and space to specify sperm fate and control sperm number.     

Surgical sperm retrieval and intracytoplasmic sperm injection as treatment of obstructive azoospermia

Male genital tract obstructions may result from infections, previous inguinal and scrotal surgery (vasectomy) and congenital bilateral absence of the vas deferens (CBAVD). Microsurgery can sometimes be successful in treating the obstruction. In other cases and in cases of failed surgical intervention, the patient can be treated by microsurgical or percutaneous epididymal sperm aspiration (MESA, PESA) or testicular sperm extraction (TESE) and intracytoplasmic sperm injection (ICSI). We present the results of 39 ICSI procedures for obstructive azoospermia in 24 couples. The aetiology of the obstruction was failed microsurgery in 11 patients, CBAVD in nine and genital infections in four. Sperm retrieval was accomplished via MESA in four cases, PESA in 18 cases and via TESE in 11 cases. TESE was only applied when PESA failed to produce enough spermatozoa for simultaneous ICSI. In six patients, the ICSI procedure was performed with cryopreserved spermatozoa after an initial PESA procedure. Fertilization occurred in 47% of the metaphase II oocytes; embryo transfer was performed in 92% of procedures and resulted in a clinical pregnancy in 13/39 procedures. Ongoing pregnancy was achieved in 10/39 procedures. One pregnancy was terminated early after prenatal investigation showed a cytogenetic abnormality (47,XX+18, Edwards syndrome). The other nine pregnancies resulted in the live birth of 10 children, without any congenital abnormalities. Epididymal and testicular retrieved spermatozoa were successfully used for ICSI to treat obstructive azoospermia, and resulted in an ongoing pregnancy in 10 of 24 couples (41.6%) after 39 ICSI procedures, a success rate of 25.6% per treatment cycle and of 27.7% per embryo transfer.      

A locus for Bowen-Conradi syndrome maps to chromosome region 12p13.3

Bowen-Conradi syndrome (BCS) is a lethal autosomal recessive disorder with an estimated incidence of 1 in 355 live births in the Hutterite population. A few cases have been reported in other populations. Here, we report the results of a genome-wide scan and fine mapping of the BCS locus in Hutterite families. By linkage and haplotype analysis the BCS locus was mapped to a 3.5 cM segment (1.9 Mbp) in chromosome region 12p13.3 bounded by F8VWF and D12S397. When genealogical relationships among the families were taken into account in the linkage analysis, the evidence for linkage was stronger and the number of potentially linked regions was reduced to one. Under the assumption that all the Hutterite patients were identical by descent for a disease-causing mutation, haplotype analysis was used to infer likely historical recombinants and thereby narrow the candidate region to a chromosomal segment shared in common by all the affected children. This study also demonstrates that BCS and cerebro-oculo-facial-skeletal syndrome (COFS) are genetically distinct.