Premature cardiovascular disease in chronic renal failure

There is a remarkable lack of reliable information about the determinants of risk of cardiovascular disease (CVD) among patients with chronic renal failure. Indeed, such patients have often been deliberately excluded from randomised trials of treatments of CVD, perhaps because of concerns about drug safety. But the absolute risk of CVD among them may be large, so the potential absolute benefits of treatments may also be large, and may well exceed any increased hazards. Hence, as well as further investigation of the underlying mechanisms of cardiac disease, it would be helpful to have some large-scale randomised trials in a wide range of renal patients of interventions (such as cholesterol-lowering drugs, antihypertensives, aspirin, B-vitamins, and antioxidant vitamins) that are of proven or suspected benefit in other settings. If safe and effective treatments can be identified, and started early in the natural history of renal failure, the exceptionally high risk of CVD experienced by these patients could be decreased before and after end-stage renal failure has occurred.

Recognized globe perforation during strabismus surgery: incidence, risk factors, and sequelae

BACKGROUND

Inadvertent perforation of the globe is a well-recognized complication of extraocular muscle surgery. We evaluated the incidence, risk factors, and sequelae of this complication at our institution.

METHODS

Medical records of patients who underwent extraocular muscle surgery at King Khaled Eye Specialist Hospital, Saudi Arabia, between September 1983 and April 1997, were reviewed for the occurrence of globe perforation. We documented preoperative visual acuity and refraction, surgical procedure, how the perforation occurred, and immediate management, as well as the sequelae of the perforation, its management, and final outcome.

RESULTS

Recognized perforations occurred in 15 of 4886 procedures, for an overall incidence rate of 3/1000. Perforations were 3 times more common in myopic eyes (>-6.00 D, P =.05) and 2 times more common in eyes with previous extraocular muscle surgery. Perforations occurred during muscle reattachment (5 cases), placement of traction sutures at the limbus (4 cases with transient hyphema), muscle disinsertion (3 cases), and placement of sutures at the muscle insertion before disinsertion (3 cases). One patient had a large scleral laceration with uveal prolapse, necessitating scleral patch graft at the time of surgery, and later had retinal detachment surgery with loss of 2 lines of visual acuity. Endophthalmitis, cataract, glaucoma, and phthisis bulbi were not encountered in our review.

CONCLUSION

The current incidence of globe perforation is low and only rarely associated with serious sequelae.

CPT-EIA assays for the detection of vancomycin resistant vanA and vanB genes in enterococci

Cycling Probe Technology (CPT) was combined with a colorimetric enzyme-immuno assay (EIA) to develop two assays for the detection of vanA and vanB genes in vancomycin resistant enterococci (VRE). The CPT-EIA assay employs a gene-specific fluorescein labeled DNA-RNA-DNA probe that gets cleaved within the probe : target duplex. The cleaved DNA probe fragments dissociate from the target, making it available for further cycling. Following the separation of cleaved probe fragments, anti-fluorescein-horseradish peroxidase antibodies are used for the detection of uncleaved probes. The two CPT-EIA assays were used to screen a collection of 440 clinical isolates (Modrusan et al., 1999). All of the 154 VanA and 131 VanB isolates were correctly identified in the vanA and vanB CPT-EIA, respectively. The VanA and VanB isolates were differentiated from vancomycin sensitive enterococci (VSE) and also from the VanC isolates. In addition, an accurate VRE detection in the CPT-EIA assay was shown with cultures grown on eight different media.

Nurse management of patients with minor illnesses in general practice: multicentre, randomised controlled trial

OBJECTIVE

To assess the acceptability and safety of a minor illness service led by practice nurses in general practice.

DESIGN

Multicentre, randomised controlled trial.

SETTING

5 general practices in south east London and Kent representing semi-rural, suburban, and urban settings.

PARTICIPANTS

1815 patients requesting and offered same day appointments by receptionists.

INTERVENTION

Patients were assigned to treatment by either a specially trained nurse or a general practitioner. Patients seen by a nurse were referred to a general practitioner when appropriate.

MAIN OUTCOME MEASURES

The general satisfaction of the patients as measured by the consultation satisfaction questionnaire. Other outcome measures included the length of the consultation, number of prescriptions written, rates of referral to general practitioners, patient's reported health status, patient's anticipated behaviour in seeking health care in future, and number of patients who returned to the surgery, visits to accident and emergency, and out of hours calls to doctors.

RESULTS

Patients were very satisfied with both nurses and doctors, but they were significantly more satisfied with their consultations with nurses (mean (SD) score of satisfaction 78.6 (16. 0) of 100 points for nurses v 76.4 (17.8) for doctors; 95% confidence interval for difference between means -4.07 to -0.38). Consultations with nurses took about 10 minutes compared with about 8 minutes for consultations with doctors. Nurses and doctors wrote prescriptions for a similar proportion of patients (nurses 481/736 (65.4%) v doctors 518/816 (63.5%)). 577/790 (73%) patients seen by nurses were managed without any input from doctors.

CONCLUSION

Practice nurses seem to offer an effective service for patients with minor illnesses who request same day appointments.

The 'chef's hat' appearance of the femoral head in cleidocranial dysplasia

Cleidocranial dysplasia (CCD) is inherited as an autosomal dominant disorder characterised by failure of membranous ossification. The condition is due to a mutation of the cbfa1 gene on chromosome 6 which has a role in the development of osteoblasts from the mesenchymal cells. In their growing years, these patients have an unusual shape of the femoral head reminiscent of a 'chef's hat'. In order to confirm the consistency of this sign, we have reviewed the radiographs of 28 patients with CCD. All except three had this appearance. The sign was also seen in patients with coxa vara associated with a variety of other conditions. The chef's hat sign may occur secondary to the particular mechanical environment created by coxa vara as well as abnormal cellular function in patients with CCD. Although coxa vara has some influence on the shape of the femoral head, it is not entirely responsible for its morphology since it was present in only six of the 28 patients with CCD.

The ‘chef’s hat’ appearance of the femoral head in cleidocranial dysplasia

Cleidocranial dysplasia (CCD) is inherited as an autosomal dominant disorder characterised by failure of membranous ossification. The condition is due to a mutation of the cbfa1 gene on chromosome 6 which has a role in the development of osteoblasts from the mesenchymal cells. In their growing years, these patients have an unusual shape of the femoral head reminiscent of a ‘chef’s hat’. In order to confirm the consistency of this sign, we have reviewed the radiographs of 28 patients with CCD. All except three had this appearance. The sign was also seen in patients with coxa vara associated with a variety of other conditions. The chef’s hat sign may occur secondary to the particular mechanical environment created by coxa vara as well as abnormal cellular function in patients with CCD. Although coxa vara has some influence on the shape of the femoral head, it is not entirely responsible for its morphology since it was present in only six of the 28 patients with CCD.

A comparison of methods currently used in clinical practice to estimate familial breast cancer risks

BACKGROUND

With the identification of genes predisposing to hereditary breast cancer, the accurate and consistent estimation of a woman's risk of developing breast cancer based on her family history is of paramount importance if national service guidelines are to be developed.

PATIENTS AND METHODS

The residual lifetime risk of developing breast cancer was estimated for 200 women attending a breast cancer genetic assessment clinic by three different methods currently in use in the UK. Risks were computed on the basis of the Cancer and Steroid Hormone (CASH) study data and were classified as 'low/moderate' (<20%) or 'high' (>20%). These risk categories are representative of those currently used to allocate surveillance and genetic testing. Risks were then compared to estimates derived by other methods used in current clinical practice, including those of Houlston and Murday.

RESULTS

The CASH data-based method ascribed 27% to the high risk category, as compared to 53% for the combined Houlston and Murday methods. A method based on the number of affected relatives alone ascribed only 14% to the high risk category. Overall, 108 (54%) women were placed in the same risk category by all three methods.

CONCLUSIONS

This study demonstrates that there is a significant degree of variability between methods currently used to estimate breast cancer risk which has serious implications for individual patient management, service provision and multicentre studies evaluating the benefits of genetic testing for breast cancer susceptibility.

Detection of vancomycin resistant genes vanA and vanB by cycling probe technology

Cycling Probe Technology (CPT) has been used to develop gene-based assays for detection of vancomycin resistance genes vanA and vanB in enterococci (VRE). Cycling Probe Technology utilizes a chimeric DNA-RNA-DNA probe that is cleaved by the enzyme RNase H when hybridized to its complementary DNA target. Conversion of full-length probe into the cleaved probe fragments is the basis for detection and quantification of the CPT reaction. Two gene-specific probes, each one unique to either the vanA or vanB gene, were utilized for development of vanA and vanB CPT assays, respectively. Both vanA and vanB CPT assays were used to determine the presence or absence of the corresponding gene in 440 clinical enterococcal isolates. The presence of vanA and vanB gene sequences was detected in 154 and 131 isolates, respectively. Phenotypic characterization of all isolates was determined through interpretation of conventional susceptibility data obtained with the disk diffusion method. Comparison between disk diffusion characterization and CPT assays revealed 11 discrepant isolates. The identity of these isolates was resolved by polymerase chain reaction (PCR) which confirmed the vanA and vanB CPT assay data. Therefore, compared to conventional phenotyping, both the vanA and vanB CPT assays appeared superior for accurate identification of VanA and VanB isolates.

Atypical vitellins in ponerine ants (Formicidae: Hymenoptera)

Higher hymenopteran vitellogenin/vitellins have been characterized as containing one large apoprotein. We show that in the ant subfamily Ponerinae, species in the tribes Odontomachini, Platythyrini, and Amblyoponini, also have a vitellin with this simple structure, containing a single apoprotein of 180-190kDa. Species in tribes Ponerini and Ectatommini, however, have vitellins containing multiple subunits. The size and number of the subunits varies, with differences even among species within the same genus. This is the first report of diversity in vitellogenin structure in the higher Hymenoptera. Vitellin and vitellogenin in Harpegnathos saltator (Ponerini) contain two large subunits of about 165kDa and two small subunits of about 45 and 43kDa. N-terminal sequence analysis suggests that provitellogenin is cleaved at two different sites, producing two large and two small subunits differing slightly in size. Diversity of vitellin types in Ponerini and Ectatommini is similar to that found in the more primitive tenthredinoid sawflies (Hymenoptera, Symphyta), and may indicate polyphyly in the Ponerinae. Insect vitellogenins and yolk proteins show considerably more diversity than originally believed, and the possibility of the functional significance of these differences should be considered.

Peak expiratory flow rate control chart in asthma care: chart construction and use in asthma care

BACKGROUND

The home monitoring of peak expiratory flow rate (PEFR), although recommended in current asthma guidelines, remains seriously underutilized by both patients and physicians. Our assessment is that this is more a statement regarding the inability of current charting methods to fulfill the promises made for PEFR monitoring, rather than a commentary regarding the usefulness of peak expiratory flow rate monitoring per se. We have adapted the theory and charting tool of the discipline of statistical process control to the daily monitoring of PEFR in the care of patients with asthma. Statistical process control charts integrate the actual PEFR values and their day-to-day variation in a manner that permits more informed decision-making. This article introduces our adaptation of statistical process control theory and charts via three case presentations.

OBJECTIVE

Report our experience in the use of statistical process control theory and charting to the monitoring of peak expiratory flow in the care of patients with asthma.

METHODS

Discussion of methodology and case reports.

CONCLUSION

This is the first report of the application of statistical process control (SPC) theory and charting to the home monitoring of peak expiratory flow rate and the clinical decision-making processes involved in the day-to-day care of patients with asthma. SPC charts integrate knowledge of actual serial PEFR measurements with knowledge of their associated serial variation. Our adaptation of this theory and its charting methodology results in a tool that loses nothing provided by the charting methods suggested in current guidelines and, at the same time, provides patient specific, statistically driven signals of significant change; facilitates identification of the reason(s) for the change in PEFR; predicts the range in which future function will occur; permits decision-making and care to be provided in an anticipatory manner; and, importantly, permits the early identification of the functionally at-risk patient. This report demonstrates that home monitoring of peak expiratory flow is a robust tool whose usefulness in the care of patients with asthma has been limited more by the paradigm in which we have required it be used than by any of the limitations of the measurement per se.

BRCA1 and BRCA2 in breast cancer families from Wales: moderate mutation frequency and two recurrent mutations in BRCA1

Mutations in the BRCA1/BRCA2 genes account for varying proportions of breast cancer families studied, and demonstrate considerable variation in mutational spectra coincident with ethnic and geographical diversity. We have screened for mutations in 17 families from Wales with two or more cases of breast cancer under age 50 and/or ovarian cancer. Eight out of 17 (47%) families had demonstrable mutations. Six out of 17 (35%) carried BRCA1 mutations and 2 out of 17 (12%) carried BRCA2 mutations. Two recurrent mutations in BRCA1 were identified, which appear to represent founder mutations in this population. These data support the existence of additional breast and ovarian cancer susceptibility genes.

Secondary posterior chamber intraocular lens implantation in children

BACKGROUND

Primary intraocular lens (IOL) implantation after cataract aspiration is a widely accepted means of correcting pediatric aphakia. However, little is available in the literature on secondary IOL implantation in children. We present our experience over the past 6 years.

METHODS

The charts of 57 aphakic children (61 eyes) who underwent secondary posterior chamber IOL implantation between January 1989 and April 1996 were reviewed. In general, these children were either intolerant of or noncompliant with their contact lenses. An attempt was made to correlate visual outcome with patient variables. Evaluation of the ciliary sulcus structure was made in selected patients by ultrasonographic biomicroscopy to reveal any changes resulting from the presence of the IOL haptic in the sulcus.

RESULTS

The age range at the time of surgery was 2 to 16 years (mean 8 y). Mean follow-up was 14 months (range 6 to 48 months). Forty-two percent of the patients had a best-corrected visual acuity of 20/40 or better and 78% saw better than 20/80. Posterior capsular opacification occurred in 10 eyes, 8 of which required neodymium:yttrium-aluminum-garnet laser capsulotomy. No major complications occurred. Ciliary sulcus evaluation by biomicroscopy did not reveal any significant ciliary body or scleral erosion. No changes were noted when the implanted sulcus was compared with the normal contralateral side.

CONCLUSION

Although follow-up was short, this review suggests that secondary posterior chamber IOL implantation is a safe alternative when other methods of correcting pediatric aphakia fail.

The Pseudomonas aeruginosa quorum-sensing signal molecule N-(3-oxododecanoyl)-L-homoserine lactone has immunomodulatory activity

Diverse gram-negative bacterial cells communicate with each other by using diffusible N-acyl homoserine lactone (AHL) signal molecules to coordinate gene expression with cell population density. Accumulation of AHLs above a threshold concentration renders the population "quorate," and the appropriate target gene is activated. In pathogenic bacteria, such as Pseudomonas aeruginosa, AHL-mediated quorum sensing is involved in the regulation of multiple virulence determinants. We therefore sought to determine whether the immune system is capable of responding to these bacterial signal molecules. Consequently the immunomodulatory properties of the AHLs N-(3-oxododecanoyl)-L-homoserine lactone (OdDHL) and N-(3-oxohexanoyl)-L-homoserine lactone (OHHL) were evaluated in murine and human leukocyte immunoassays in vitro. OdDHL, but not OHHL, inhibited lymphocyte proliferation and tumor necrosis factor alpha production by lipopolysaccharide-stimulated macrophages. Furthermore, OdDHL simultaneously and potently down-regulated the production of IL-12, a Th-1-supportive cytokine. At high concentrations (>7 x 10(-5) M) OdDHL inhibited antibody production by keyhole limpet hemocyanin-stimulated spleen cells, but at lower concentrations (<7 x 10(-5) M), antibody production was stimulated, apparently by increasing the proportion of the immunoglobulin G1 (IgG1) isotype. OdDHL also promoted IgE production by interleukin-4-stimulated human peripheral blood mononuclear cells. These data indicate that OdDHL may influence the Th-1-Th-2 balance in the infected host and suggest that, in addition to regulating the expression of virulence determinants, OdDHL may contribute to the pathogenesis of P. aeruginosa infections by functioning as a virulence determinant per se.

The effects of femoral intramedullary reaming on pulmonary function in a sheep lung model

Two methods of intramedullary fixation of fractures of the middle of the femoral shaft were evaluated in a sheep model to determine the effect of femoral reaming on pulmonary function. The effect of a modified reamer was also studied. A second experiment with the same model was performed to evaluate the relationship between embolization and pulmonary dysfunction. This experiment involved two groups of sheep--those with normal lungs and those with contused lungs--divided into subgroups--those that had nailing with reaming and those that had nailing without reaming. Intracardiac ultrasound was used to measure the magnitude and duration of transvenous particulate embolization during the operations. Both experiments involved hemodynamic monitoring during and after the nailing. The pulmonary tissue was examined histologically after the animals were killed. The hemodynamic monitoring revealed only a transient increase in pulmonary vascular resistance in the animals that had femoral nailing with reaming in both experiments. The modified reamer had no effect on the pulmonary response. Histological analysis of pulmonary tissue demonstrated a significant increase in the number of fat emboli in both the animals that had nailing with reaming and the animals that had nailing without reaming compared with the control animals. Intravascular ultrasound revealed that the operative maneuver associated with the greatest number of emboli was opening of the intramedullary canal with the awl. The first two passes of the reamer produced more emboli and embolism of longer duration than did the later passes. Pulmonary confusion did not increase the risk of pulmonary dysfunction due to intramedullary nailing in this model.

Excursion and strain of the median nerve

Five fresh-frozen transthoracic cadaver specimens (ten upper extremities) were dissected in order to measure excursion and strain of the median nerve at the wrist and the elbow in association with different positions of the shoulder, elbow, wrist, and fingers. The relationships between motions of the joints and excursion and strain at the wrist and the elbow as well as between excursion and strain were also determined. When the wrist was moved from 60 degrees of extension to 65 degrees of flexion, the median nerve at the wrist underwent a mean total excursion of 19.6 millimeters (9.2 +/- 1.38 millimeters [mean and standard deviation] in extension and 10.4 +/- 1.50 millimeters in flexion). The change in strain was not measurable secondary to nerve-wrinkling. Motion of the fingers from hyperextension to full flexion caused a mean total excursion of 9.7 millimeters (6.3 +/- 1.31 millimeters in hyperextension and 3.4 +/- 1.04 millimeters in flexion) and a change in strain of 19.0 per cent. This change in strain became more pronounced when the wrist and the fingers moved in synergy. Such strain, if constant, has been shown to decrease microvascular perfusion and nerve conduction in rabbits. With motion of the shoulder, the mean total excursion of the median nerve at the elbow was 9.1 millimeters (4.4 +/- 1.64 millimeters in abduction and 4.7 +/- 1.81 millimeters in adduction) and the change in strain was 13.3 per cent. With motion of the elbow, the mean total excursion was 12.3 millimeters (12.3 +/- 4.20 millimeters in flexion and zero millimeters in the resting position) and the change in strain was not measurable because of the wrinkle effect in flexion. With motion of the wrist, the mean total excursion was 5.6 millimeters (4.3 +/- 1.95 millimeters in extension and 1.25 +/- 0.81 millimeters in flexion) and the change in strain was 14.8 per cent. With motion of the fingers, the mean total, excursion was 3.4 millimeters (2.6 +/- 1.13 millimeters in hyperextension and 0.80 +/- 0.92 millimeter in flexion) and the change in strain was 10.3 per cent. Motion of the wrist and the fingers induced profound excursion of the median nerve at the wrist, whereas motion of the shoulder and the elbow induced marked excursion of the median nerve at the elbow. These excursions were much more pronounced when a number of joints were moved in a composite manner. Any factor that might limit normal excursion, such as scarring, could induce strains that could adversely affect the function of the median nerve. The finding that the position and movement of the limb had a profound effect on excursion and strain of the median nerve at the wrist and the elbow may aid in the understanding of the pathophysiology of median-nerve neuropathy.

First trimester aneuploidy screening using nuchal translucency, free beta human chorionic gonadotrophin and maternal age

Screening for aneuploidy using maternal age has a low detection rate and high false positive rate. Second trimester maternal serum screening increases trisomy 21 detection and decreases the false positive rate. First trimester screening would enable definitive diagnosis with chorionic villus sampling, and simple surgical termination of affected pregnancies would still be an option. Nuchal translucency (NT), free beta human chorionic gonadotrophin (f beta HCG) and maternal age were assessed in 302 patients before chorionic villus sampling. NT positively and f beta HCG negatively correlated with gestation, but neither correlated with maternal age nor with each other. Both NT and f beta HCG were increased in trisomy 21. NT was increased and f beta HCG was decreased in trisomy 18. Multivariate discriminant analysis enabled 87.5% detection of trisomy 21 in this high-risk population, for a 14% false positive rate. In a simulated normal population, using a risk cut-off of 1 in 250, 71% detection was achieved for a 7% false positive rate. The combination of NT, f beta HCG and maternal age is a simple, readily available and viable first trimester screening strategy.

Propylthiouracil-induced hepatotoxicity

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Management and outcome of pneumothoraces in patients infected with human immunodeficiency virus

To better understand the natural history, management, and outcome of pneumothoraces in HIV-infected patients, we reviewed hospital charts and chest radiographs of HIV-infected adults discharged from the University of Maryland Medical Center over a 6-year period. Sixty pneumothoraces occurred in 39 patients. Twenty-three pneumothoraces resulted from trauma and 37 were spontaneous. Thirty-two (86%) of the spontaneous pneumothoraces occurred in patients with Pneumocystis carinii pneumonia (PCP). Eight percent of the traumatic pneumothoraces in patients who did not have PCP resolved. Patients who had pneumothorax as well as PCP were more difficult to manage and had a poorer outcome (50% mortality) than those who did not have PCP (25% mortality).

The role of nourishment in oogenesis

Oogenesis in insects is typically a nutrient-limited process, triggered only if sufficient nourishment is available. This nourishment can be acquired during the larval or adult stage, depending on the insect. Timing of food intake will have major effects on mechanisms of hormonal control. When nourishment for eggs is taken primarily by adults, insufficient nutrition inhibits egg development through mechanisms such as inhibition of corpora allata, as seen in Orthoptera and Blattaria. In adult Diptera, lack of protein inhibits release of brain factors that produce reproductive competency or ovarian stimulation. Lepidoptera have been characterized as lacking substantial regulation of oogenesis because egg development is underway at emergence. Many species for which ecological data are available do not mobilize reserves carried over from the larval stage until they feed as adults. The endocrine mechanisms underlying these systems are poorly understood. In many insects, mating and activity can affect nutritional state and therefore oogenesis. Mating can stimulate oogenesis through mobilization of reserves or through nutritional contributions by males to females. Activity, especially flight, and oogenesis can compete for energy. The flight apparatus, especially the muscle, can also compete with oogenesis for protein. Social insects exhibit extreme specializations in oogenesis; females range in fertility from completely sterile to hyperfecund. Food flow within colonies is a major factor regulating fecundity. Finally, maternal nourishment is not needed for oogenesis in parasitoids and pseudoplacental viviparous insects, which produce eggs with little or no yolk. Virtually nothing is known about the endocrine regulation of oogenesis on these insects.