Fluoroscopically guided transcervical fallopian tube recanalization of post-sterilization reversal mid-tubal obstructions

PURPOSE

To assess the technical success and early outcome of fluoroscopically guided transcervical fallopian tube recanalization (FTR) in mid-tubal occlusion following sterilization reversal surgery.

METHODS

From July 1995 to January 1998, patients with greater than 12 months secondary infertility underwent hysterosalpingography (HSG). FTR was performed in proximal or mid-tubal occlusion. Cases of FTR in mid-tubal occlusion were included in this study. Technical success (defined as complete tubal patency) using a standard guidewire and hydrophilic glidewire, the number of patients with at least one patent tube, and the intrauterine and ectopic pregnancy rates were determined.

RESULTS

Twenty-six infertile patients with previous sterilization reversal underwent HSG. Eight of 26 (31%) patients (mean age 32 years, range 23-37 years), had attempted FTR for mid-tubal occlusion at the site of surgical anastomosis. Fourteen tubes were attempted as there were two previous salpingectomies. Technical success was achieved in eight of 14 (57%) tubes attempted, resulting in five of eight (62%) patients having at least one patent tube. At follow-up (mean 18 months, range 12-28 months) in these five patients there was one intrauterine pregnancy. There were no ectopic pregnancies.

CONCLUSIONS

FTR in mid-tubal obstruction in infertile patients following sterilization reversal surgery is technically feasible and may result in intrauterine pregnancy. In this small group there was a lower technical success rate and lower pregnancy rate than in unselected proximal tubal occlusion.

Mitogen-activated protein kinase is involved in N-methyl-D-aspartate receptor regulation of amyloid precursor protein cleavage

Glutamate is the principal excitatory neurotransmitter in the mammalian brain. Several lines of evidence suggest that glutamatergic hypoactivity exists in the Alzheimer's disease brain, where it may contribute to both brain amyloid burden and cognitive dysfunction. Although metabotropic glutamate receptors have been shown to alter cleavage of the amyloid precursor protein, little attention has been paid to the role of N-methyl-D-aspartate receptors in this process. We now report that activation of N-methyl-D-aspartate receptors in transiently transfected human embryonic kidney 293 cells increases production of the soluble amyloid precursor protein derivative. Moreover, using both pharmacological and gene transfer techniques, we show that this effect is largely due to activation of the mitogen-activated protein kinase cascade, specifically the pathway leading to activation of extracellular signal-regulated protein kinase but not other mitogen-activated protein kinases. These observations further our understanding of the pathways that regulate amyloid precursor protein cleavage, and buttress the notion that regulation of amyloid precursor protein cleavage is critically dependent upon the mitogen-activated protein kinase cascade.

Effectiveness and acceptability of a newly designed hip protector: a pilot study

Hip fracture has a significant economic and personal cost, involving hospital admission and functional impairment for elderly people. To assess the benefit of using a newly designed hip protector (new material and new design) to prevent fracture in a realistic setting, a randomised intervention-control design was used to trial the effectiveness of pads worn by high falls risk residents (n=71) in nursing home for 9 months. 40 residents were in the intervention group and 31 were in the control group. A profile of falls, including time of day, and orientation was obtained to demonstrate the potential effectiveness of the protectors for injury prevention. Acceptance of the hip protector was also surveyed amongst nursing home staff and residents. One hundred and one falls and six fractures occurred in the control group. In contrast, one hundred and ninety one falls and three fractures occurred in the hip protector (pads) group. The three fractures in the protector wearing group occurred when pads were not in place. This was extrapolated as 1 in every 16.8 falls and 1 in every 63.7 falls resulting in fracture in the two groups, respectively. The relative risk of fracture was 0.264 (95% CI=0.073-0.959) when the fracture incidence rate in the intervention group (three fractures per 191 falls) was compared to the control group (six fractures per 101 falls). This is a statistically significant result and implies that this newly designed hip protector is effective in preventing hip fracture. The majority of falls occurred during the day, which was when protectors were worn in this study, but the data on orientation was incomplete, with direction unknown in 74% of falls. Compliance was an issue, which was interpreted as only 50.3% of falls recorded with protectors in place. Dementia was identified as the explanation for this as the pads were often removed by these residents who comprised the majority of participants. Perception of low risk was the primary barrier to residents accepting the intervention. Comfort of protectors was not a significant concern for staff or residents, and only staff described appearance as an issue. In conclusion, the newly designed hip protector is protective against fractures in a realistic setting. Compliance and acceptance of the protectors will ultimately determine the viability of this prophylaxis.

The use of a thrombus-specific ultrasound contrast agent to detect thrombus in arteriovenous fistulae

RATIONALE AND OBJECTIVES

To evaluate the use of a new thrombus-specific ultrasound contrast agent, MRX-408, in the ultrasonic detection of thrombus in arteriovenous (AV) fistulae.

METHODS

Six purpose-bred mongrels with two AV fistulae each were imaged with gray-scale ultrasound 7 weeks after graft implantation before and after the intravenous bolus injection of MRX-408 (a GPIIb receptor-targeted ultrasound contrast agent). Pre- and postcontrast videotaped segments were randomized and reviewed by four radiologists blinded to the presence of thrombus in the grafts.

RESULTS

After the use of MRX-408, there was improved visualization of thrombus within the grafts (P < 0.0001). This was due to the enhancement of the thrombus (P < 0.0001). The improved visualization and contrast enhancement were more marked in the grafts that contained thrombus nonhyperechoic to surrounding soft tissues.

CONCLUSIONS

MRX-408 demonstrated better visualization of thrombus within AV fistulae. This was shown in both patent and occluded grafts. These results are encouraging and suggest that this contrast agent merits further development.

Some clinical factors contributing to the development of the diabetic foot

Clinical neurological studies, blood pressure measurements and some haematological investigations were performed on a random sample of forty-four patients, at the Diabetes Out-Patient Clinic of the University Hospital of the West Indies (UHWI), to examine some of the factors that predispose to the development of the diabetic foot. Our results revealed that 86% of the patients had elevated glycosylated haemoglobin (HbA1 > 9.0%), 82% had clinical signs of peripheral sensory neuropathy, 29% had signs of autonomic neuropathy in addition to peripheral sensory neuropathy. Sixty-one per cent (61%) of the patients had ankle/arm systolic blood pressure ratio less than 1.0 and were diagnosed as having peripheral vascular disease (PVD). The group with neuropathy was found to have a significantly lower diastolic blood pressure (p < 0.0005) than the group without neuropathy. We believe that hyperglycaemia-induced vasodilation (indicated by a lower diastolic blood pressure) in a significant number of diabetics resulted in compensatory shunting of blood from the deeper tissues, including nerves, to the periphery. The resulting endoneural hypoxia could be responsible for the unusually high incidence of peripheral sensory neuropathy detected in this sample of diabetic patients. Metabolic factors may also play a role.

Surfactant protein A binds to the fusion glycoprotein of respiratory syncytial virus and neutralizes virion infectivity

Collectins are a family of calcium-dependent collagenous lectins that appear to be important in innate host defense. We investigated the ability of three human collectins, namely, lung surfactant proteins A (SP-A) and D (SP-D) and the serum mannose-binding protein (MBP), to bind to the surface glycoproteins of respiratory syncytial virus (RSV). SP-A was shown to bind to the F (fusion) glycoprotein but not to the viral G (attachment) glycoprotein, and binding was completely abrogated in the presence of EDTA. Neither SP-D nor MBP bound to either glycoprotein. SP-A also neutralized RSV in a calcium dependent fashion. These results support a role for SP-A in the defense of infants against infection with RSV and indicate a possible mechanism for its protective activity.

A new sensor for monitoring chest wall motion during high-frequency oscillatory ventilation

The recently developed technique of fibre optic respiratory plethysmography (FORP) has been modified to monitor the rapid, small amplitude movements of the chest wall during high-frequency oscillatory ventilation (HFOV). The FORP sensor is an expandable belt encircling the chest, in which is housed a fibre optic loop that alters its radius of curvature as a function of chest perimeter. These curvature changes cause variations in macrobending losses of light transmitted through the fibre, which are proportional to the chest perimeter. Dynamic measurement of transmitted light intensity can hence be used to monitor chest wall motion (CWM). For application to HFOV, the design of the FORP belt was altered to increase sensitivity and the materials were chosen to maximise macrobending effects induced by the CWM. FORP was tested in four piglets ventilated with HFOV, both in the normal and surfactant-deficient lung. Measurement of CWM was possible over the full range of tidal volumes and ventilation frequencies used during HFOV. In all cases, the measured frequency of the CWM fell within 3% of the applied ventilation frequency. In addition, the technique was sufficiently sensitive to detect changes in the amplitude of CWM in response to changes in applied tidal volume. It is anticipated that application of this new non-invasive measurement device will lead to an increased understanding of the dynamics of chest and abdominal wall motion during HFOV.

Expression and characterisation of the ovine respiratory syncytial virus (ORSV) G protein for use as a diagnostic reagent

Respiratory syncytial virus (RSV) causes severe lower respiratory tract infection in children and calves. Antibodies to ovine RSV (ORSV) are common in sheep, but the clinical disease is not well defined. There is no report of ORSV infection in Australian sheep although respiratory distress syndrome has been described. This discrepancy may be due to the lack of a suitable diagnostic test. In this report, we have characterised the ORSV G protein in an attempt to study its relatedness to human and bovine RSV (HRSV, BRSV) and for use in the development of a suitable diagnostic assay. Full length and a truncated variant of ORSV G protein were expressed in mammalian cells and the expressed proteins characterised by indirect immunofluorescence and radioimmunoprecipitation assays. Our results indicate that like HRSV, the ORSV G protein is heavily glycosylated. The expressed protein was membrane bound as well as secreted and could be purified from culture supernatants and may be suitable for use in development of a diagnostic assay.

Immunologic and virologic status after 14 to 18 years of infection with an attenuated strain of HIV-1. A report from the Sydney Blood Bank Cohort

BACKGROUND AND METHODS

The Sydney Blood Bank Cohort consists of a blood donor and eight transfusion recipients who were infected before 1985 with a strain of human immunodeficiency virus type 1 (HIV-1) with a deletion in the region in which the nef gene and the long terminal repeat overlap. Two recipients have died since 1994, at 77 and 83 years of age, of causes unrelated to HIV infection; one other recipient, who had systemic lupus erythematosus, died in 1987 at 22 years of age of causes possibly related to HIV. We present longitudinal immunologic and virologic data on the six surviving members and one deceased member of this cohort through September 30, 1998.

RESULTS

The five surviving recipients remain asymptomatic 14 to 18 years after HIV-1 infection without any antiretroviral therapy; however, the donor commenced therapy in February 1999. In three recipients plasma concentrations of HIV-1 RNA are undetectable (<200 copies per milliliter), and in two of these three the CD4 lymphocyte counts have declined by 9 and 30 cells per cubic millimeter per year (P=0.3 and P=0.5, respectively). The donor and two other recipients have median plasma concentrations of HIV-1 RNA of 645 to 2850 copies per milliliter; the concentration has increased in the donor (P<0.001). The CD4 lymphocyte counts in these three cohort members have declined by 16 to 73 cells per cubic millimeter per year (P<0.001). In the recipient who died after 12 years of infection, the median plasma concentration of HIV-1 RNA was 1400 copies per milliliter, with a decline in CD4 lymphocyte counts of 17 cells per cubic millimeter per year (P=0.2).

CONCLUSIONS

After prolonged infection with this attenuated strain of HIV-1, there is evidence of immunologic damage in three of the four subjects with detectable plasma HIV-1 RNA. The CD4 lymphocyte counts appear to be stable in the three subjects in whom plasma HIV-1 RNA remains undetectable.

Review of University of British Columbia Family Practice Resident Research Projects 1990-1997

BACKGROUND

Resident research projects can be an important component of building a strong and diversified research presence in family medicine. One of the requirements for graduation from the University of British Columbia (UBC) Family Practice Residency Program is that family practice residents complete a scholarly piece of work.

METHODS

UBC family practice resident projects from 1990-1997 were reviewed and classified by methodology. A survey was sent to 251 former residents to determine 1) if their project was published, 2) if not, was there any interest in publication, and 3) what were the main reasons for not pursuing publication. Fifteen projects were selected as suitable for publication and were, with permission of the resident, submitted to medical journals.

RESULTS

Sixty-nine percent of the resident projects involved data collection and hypothesis testing, and 40% were cross-sectional, of which patient surveys were the most common method. A total of 190 former residents (71%) have responded to our survey. Seven percent of respondents stated that their project had been published, and 55% would have liked to have tried to publish their project. Of the 15 resident projects we submitted for publication, seven were accepted.

CONCLUSIONS

Family practice residents are capable of producing a wide variety of research projects. Only a minority of projects are being published despite the fact that the majority of residents are interested in pursuing publication. Greater assistance by faculty can increase publication of research projects.

A clinical approach to dental nutrition among the elderly: a description and discussion of geriatric dental nutrition

This paper describes the role of nutrition in dentistry, especially as it relates to elderly patients. The nutritional aspects are well understood, but seldom considered in treatment plan formulation and execution, even in an academic health setting. When dental school programs are shown to have clinical relevance to a target population and are faculty supported, they are most successful. This is the case at the University of Tennessee College of Dentistry in Memphis. The role of the Nutritionist focuses on the periodontal and dental aspects of geriatric patient exposure to disease causing agents in the diet. Nutritionist, dentist, student and patient all participate in a team effort to lower patient exposures and the development of a healthful diet. In this clinical approach to geriatric patient dental nutrition, all parties contribute to the success of the whole.

Respiratory syncytial virus G glycoprotein expressed using the Semliki Forest virus replicon is biologically active

The respiratory syncytial virus (RSV) G glycoprotein mediates attachment of RSV to cells via an unknown receptor. To study G glycoprotein function we have cloned two variants of the RSV G gene into a Semliki Forest virus (SFV) expression vector, a full length (rG) and soluble (srG) G glycoprotein variant. By immunofluorescence microscopy, rG was found to be predominantly membrane associated, while srG was mostly cytoplasmic. The rG (80-85 kDa) and srG (75-80 kDa) constructs produced heavily glycosylated proteins, however they were slightly smaller than the G glycoprotein expressed in RSV infected HEp-2 cells (85-90 kDa). The biological activity of purified srG was tested by its ability to bind to RSV permissive cells. Purified srG bound to HEp-2 cells and the amount bound increased linearly with the quantity added. Binding was not saturable with the small quantities of protein available. Binding of srG to HEp-2 cells was inhibited (67-68%) by MAb 30 and neutralising anti-G MAb 29. Nonpermissive SF9 insect cells bound 20-50 times less srG than HEp-2 cells. SFV expressed recombinant RSV G glycoprotein should be useful for studying interactions between the RSV G glycoprotein and cells.

Regulation of amyloid precursor protein cleavage

Multiple lines of evidence suggest that increased production and/or deposition of the beta-amyloid peptide, derived from the amyloid precursor protein, contributes to Alzheimer's disease. A growing list of neurotransmitters, growth factors, cytokines, and hormones have been shown to regulate amyloid precursor protein processing. Although traditionally thought to be mediated by activation of protein kinase C, recent data have implicated other signaling mechanisms in the regulation of this process. Moreover, novel mechanisms of regulation involving cholesterol-, apolipoprotein E-, and stress-activated pathways have been identified. As the phenotypic changes associated with Alzheimer's disease encompass many of these signaling systems, it is relevant to determine how altered cell signaling may be contributing to increasing brain amyloid burden. We review the myriad ways in which first messengers regulate amyloid precursor protein catabolism as well as the signal transduction cascades that give rise to these effects.

Hantavirus reservoir hosts associated with peridomestic habitats in Argentina

Five species of sigmodontine rodents have been identified in Argentina as the putative reservoirs of six circulating hantavirus genotypes. Two species of Oligoryzomys are associated with the genotypes causing hantavirus pulmonary syndrome, Oligoryzomys flavescens for Lechiguanas and O. longicaudatus for Andes and Oran genotypes. Reports of human cases of hantavirus pulmonary syndrome prompted rodent trapping (2,299 rodents of 32 species during 27,780 trap nights) at potential exposure sites in three disease-endemic areas. Antibody reactive to Sin Nombre virus was found in six species, including the known hantavirus reservoir species. Risk for peridomestic exposure to host species that carry recognized human pathogens was high in all three major disease-endemic areas.

Sexually dimorphic responses to neonatal basal forebrain lesions in mice: I. Behavior and neurochemistry

The nucleus basalis magnocellularis (nBM) provides the primary source of cholinergic input to the cortex. Neonatal lesions of the nBM produce transient reductions in cholinergic markers, persistent abnormalities in cortical morphology, and spatial navigation impairments in adult mice. The present study examined sex differences in the effects of an electrolytic nBM lesion on postnatal day 1 (PND 1) in mice on behavior and neurochemistry in adulthood. Mice were lesioned on PND 1 and tested at 8 weeks of age on a battery of behavioral tests including passive avoidance, cued and spatial tasks in the Morris water maze, simple and delayed nonmatch to sample versions of an odor discrimination task, and locomotor activity measurements. Following behavioral testing, mice were sacrificed for either morphological assessment or neurochemical analysis of a cholinergic marker or catecholamines. There were no lesion or sex differences in acquisition or retention of passive avoidance, performance of the odor discrimination tasks, or activity levels. Control mice showed a robust sex difference in performance of the spatial water maze task. The lesion produced a slight cued but more dramatic spatial navigation deficit in the water maze which affected only the male mice. Neurochemical analyses revealed no lesion-induced changes in either choline acetyltransferase activity or levels of norepinephrine or serotonin at the time of testing. The subsequent report shows a sex difference in lesion-induced changes in cortical morphology which suggests that sexually dimorphic cholinergic influences on cortical development are responsible for the behavioral deficits seen in this study.

Radiosensitive human tumour cell lines show misrepair of DNA termini

Physical measures of the rejoining of radiation-induced breaks in DNA strands are limited in terms of sensitivity and the fact that they do not assess the fidelity with which the rejoining occurs. In this report, transfection of cleaved plasmid has been used as a probe for repair in three radiosensitive tumour cell lines and shown them to have low repair fidelity compared with resistant cells. Errors in the repair of linear plasmid were found by Southern analysis, in keeping with the measured repair fidelity. Radiosensitive tumour cells showed few errors in the uptake and integration of circular plasmid, in contrast to ataxia-telangiectasia (A-T) cells. In the neuroblastoma HX142, the repair of blunt-ended linear plasmid was associated with deletions of > 1 kb; staggered-ended linear plasmid was repaired with small insertions and circular plasmid integration was intact in > 60% of the copies. The neuroblastoma SKN.SH, processed staggered-ended plasmid by insertions of a variety of sizes, but processed circular plasmid largely error-free. In contrast, A-T cells (AT5BIVA) had the same spectrum of errors irrespective of the form of plasmid transfected. Cell fusion between HX142 and AT5BIVA showed complementation to a resistant phenotype, suggesting that misrepair in the tumour cell did not result from somatic mutation in the ATM gene. In conclusion, radiosensitive tumours show evidence of misrepair of DNA termini, with a mechanism which is functionally and genetically distinct from that in A-T cells.

Coresistance to zidovudine and foscarnet is associated with multiple mutations in the human immunodeficiency virus type 1 reverse transcriptase

Human immunodeficiency virus type 1 (HIV-1) isolates obtained from a patient with AIDS were assessed for coresistance to foscarnet and zidovudine. An HIV-1 strain (AP20) coresistant to foscarnet and zidovudine was isolated after 20 months of continuous combination therapy. The reverse transcriptase (RT) gene of AP20 had 41 substitutions which were different from the HXB2-D sequence and 9 that were different from the sequence of its foscarnet-sensitive, zidovudine-resistant progenitor virus (AP6). Six of these mutations were nonpolymorphic (T39A, V108I, K166R, K219R, K223Q, and L228R). Both strains had the conventional mutations mediating zidovudine resistance. In vivo selection may result in HIV-1 strains that are coresistant to foscarnet and zidovudine, but coresistance appears to require a complex evolutionary path and multiple RT mutations.