Efficacy, Feasibility, and Safety of the X-Tack Endoscopic HeliX Tacking System: A Multicenter Experience

BACKGROUND AND AIMS

The application of endoscopic suturing has revolutionized defect closures. Conventional over-the-scope suturing necessitates removal of the scope, placement of the device, and reinsertion. A single channel, single sequence, through-the-scope suturing device has been developed to improve this process. This study aims to describe the efficacy, feasibility, and safety of a through-the-scope suturing device for gastrointestinal defect closure.

METHODS

This was a retrospective multicenter study involving 9 centers of consecutive adult patients who underwent suturing using the X-Tack Endoscopic HeliX Tacking System (Apollo Endosurgery). The primary outcomes were technical success and long-term clinical success. Secondary outcomes included adverse events, recurrence, and reintervention rates.

RESULTS

In all, 56 patients (mean age 53.8, 33 women) were included. Suturing indications included fistula repair (n=22), leak repair (n=7), polypectomy defect closure (n=12), peroral endoscopic myotomy (POEM) site closure (n=7), perforation repair (n=6), and ulcers (n=2). Patients were followed at a mean duration of 74 days. Overall technical and long-term clinical success rates were 92.9% and 75%, respectively. Both technical and clinical success rates were 100% for polypectomies, POEM-site closures, and ulcers. Success rates were lower for the repair of fistulas (95.5% technical, 54.5% clinical), leaks (57.1%, 28.6%), and perforations (100%, 66.7%). No immediate adverse events were noted.

CONCLUSION

This novel, through-the-scope endoscopic suturing system, is a safe and feasible method to repair defects that are ≤3 cm. The efficacy of this device may be better suited for superficial defects as opposed to full-thickness defects. Larger defects will need more sutures and probably a double closure technique to provide a reinforcement layer.

Infectious Colitis Associated With Ipilimumab Therapy

Ipilimumab is a monoclonal antibody against cytotoxic T lymphocyte-associated molecule-4 and is thought to promote anti-tumor activity by enhancing cell mediated immunity. It is one of the few therapies shown to improve overall survival in metastatic melanoma. Given its mechanism of action, the drug is associated with significant immune-related adverse events with the gastrointestinal system being commonly involved. Our patient is a 22-year-old female with stage IVA melanoma on ipilimumab therapy who presented with fever, diarrhea and abdominal pain. She gave a history of recent travel to a wedding where several other guests in attendance had also developed diarrheal illnesses. Her colonoscopy and pathology were consistent with ipilimumab-induced colitis. Her stool culture returned positive for Salmonella enteritides. She was treated with prednisone and ciprofloxacin with resolution of her symptoms. In our case, we describe ipilimumab-induced colitis where an infectious pathogen was identified with temporal relationship to symptoms and could be suggestive of a causal relationship.

Multiphoton fluorescence lifetime imaging shows spatial segregation of secondary metabolites in Eucalyptus secretory cavities

Multiphoton fluorescence lifetime imaging provides an excellent tool for imaging deep within plant tissues while providing a means to distinguish between fluorophores with high spatial and temporal resolution. Ideal candidates for the application of multiphoton fluorescence lifetime imaging to plants are the embedded secretory cavities found in numerous species because they house complex mixtures of secondary metabolites within extracellular lumina. Previous investigations of this type of structure have been restricted by the use of sectioned material resulting in the loss of lumen contents and often disorganization of the delicate secretory cells; thus it is not known if there is spatial segregation of secondary metabolites within these structures. In this paper, we apply multiphoton fluorescence lifetime imaging to investigate the spatial arrangement of metabolites within intact secretory cavities isolated from Eucalyptus polybractea R.T. Baker leaves. The secretory cavities of this species are abundant (up to 10 000 per leaf), large (up to 6 nL) and importantly house volatile essential oil rich in the monoterpene 1,8-cineole, together with an immiscible, non-volatile component comprised largely of autofluorescent oleuropeic acid glucose esters. We have been able to optically section into the lumina of secretory cavities to a depth of ∼80 μm, revealing a unique spatial organization of cavity metabolites whereby the non-volatile component forms a layer between the secretory cells lining the lumen and the essential oil. This finding could be indicative of a functional role of the non-volatile component in providing a protective region of low diffusivity between the secretory cells and potentially autotoxic essential oil.

Navigating transdermal diffusion with multiphoton fluorescence lifetime imaging

We demonstrate the potential of fluorescence lifetime imaging by time-correlated single-photon counting as a method for monitoring the transdermal diffusion pathway and diffusion rate of pharmaceuticals in human skin. The current application relies on observing subtle changes in the fluorescence lifetime of the intrinsic fluorophores present in the intracellular region between corneocytes of the stratum corneum. We have comprehensively characterized the measured fluorescence lifetimes from intracorneocyte junctions in three skin section types (dermatomed skin, epidermal membranes and stratum corneum) revealing statistically significant differences of the short lifetime component between each of the types, which we attribute to the sample preparation and imaging method. We show using epidermal membrane sections that application of a drug/solvent formulation consisting of ethinyl estradiol and spectroscopic grade ethanol to the surface gives rise to a slight but statistically significant shortening of the fluorescence lifetime of the long-lived emitting species present in the sample, from approximately 2.8 ns to 2.5 ns. The method may be useful for future studies where the kinetics and pathways of a variety of applied formulations could be investigated.

Cost-sharing strategies combining targeted public subsidies with private-sector delivery achieve high bednet coverage and reduced malaria transmission in Kilombero Valley, southern Tanzania

Background

Cost-sharing schemes incorporating modest targeted subsidies have promoted insecticide-treated nets (ITNs) for malaria prevention in the Kilombero Valley, southern Tanzania, since 1996. Here we evaluate resulting changes in bednet coverage and malaria transmission.

Methods

Bednets were sold through local agents at fixed prices representing a 34% subsidy relative to full delivery cost. A further targeted subsidy of 15% was provided to vulnerable groups through discount vouchers delivered through antenatal clinics and regular immunizations. Continuous entomological surveys (2,376 trap nights) were conducted from October 2001 to September 2003 in 25 randomly-selected population clusters of a demographic surveillance system which monitored net coverage.

Results

Mean net usage of 75% (11,982/16,086) across all age groups was achieved but now-obsolete technologies available at the time resulted in low insecticide treatment rates. Malaria transmission remained intense but was substantially reduced: Compared with an exceptionally high historical mean EIR of 1481, even non-users of nets were protected (EIR [fold reduction] = 349 infectious bites per person per year [×4]), while the average resident (244 [×6]), users of typical nets (210 [×7]) and users of insecticidal nets (105 [×14]) enjoyed increasing benefits.

Conclusion

Despite low net treatment levels, community-level protection was equivalent to the personal protection of an ITN. Greater gains for net users and non-users are predicted if more expensive long-lasting ITN technologies can be similarly promoted with correspondingly augmented subsidies. Cost sharing strategies represent an important option for national programmes lacking adequate financing to fully subsidize comprehensive ITN coverage.

[Prevalence, genetic diversity and multiplicity of Plasmodium falciparum infection in school children in central Cote d'Ivoire]

A study was carried out in the village of Taabo, located in the vicinity of a large man-made lake in central Côte d'Ivoire. The objectives were (i) to determine the level of prevalence, genetic diversity and multiplicity of Plasmodiumfakiparum infection in schoolchildren and (ii) to compare the diagnostic performance of light microscopy and polymerase chain reaction (PCR). A total of 424 schoolchildren ranging in age from 5 to 15 years underwent diagnostic testing using both light microscopy of blood smears and PCR. Multiplicity of P. falciparum infection was investigated in 196 children (46.2%). The prevalence of malaria was 54.7% based on light microscopy and 83.9% based on PCR. Genotyping based on polymorphism in the length of the restriction fragment of the gene encoding the merozoite surface protein-2 (msp2) showed that 86.5% of cases involved multiple infection with a geometric mean of 3.87 genotypes per positive child. There was a strong positive correlation between multipcity of infection and parasite density in the 56-year old age group. A total of 50 genotypes including six observed for the first time were identified and classified into families with similar-sized sequence groups: 26 x FC27 (52%) and 24 x 3D7 (48%). In comparison with PCR, the sensitivity and specificity of light microscopy for diagnosis of P. falciparum was 81.3% and 88.2% respectively. Data are discussed in the light of similar studies carried out in sub-Saharan Africa and elsewhere. These findings can serve as a basis for monitoring the longterm effect of major water resource management projects on the prevalence, genetic diversity and multiplicity of P. falciparum infection.

Code of practice for food handler activities

BACKGROUND

The food industry regulates various aspects of food handler activities, according to legislation and customer expectations. The purpose of this paper is to provide a code of practice which delineates a set of working standards for food handler hygiene, handwashing, use of protective equipment, wearing of jewellery and body piercing.

METHODS

The code was developed by a working group of occupational physicians with expertise in both food manufacturing and retail, using a risk assessment approach. Views were also obtained from other occupational physicians working within the food industry and the relevant regulatory bodies. The final version of the code (available in full as Supplementary data in Occupational Medicine Online) therefore represents a broad consensus of opinion.

CONCLUSION

The code of practice represents a set of minimum standards for food handler suitability and activities, based on a practical assessment of risk, for application in food businesses. It aims to provide useful working advice to food businesses of all sizes.

The Child Dental Control Assessment (CDCA) in youth: reliability, validity and cross-cultural differences

AIM

The Child Dental Control Assessment (CDCA) measures children's preferred control strategies in the dental situation. Three studies are reported, assessing aspects of this instrument in youths from the USA, Japan and Australia. In particular, measurements were made as to the reliability and validity of this instrument in this age group in the three cultures, as well as comparing some results across cultures.

STUDY DESIGN

These studies used a questionnaire design.

METHODS

Questionnaires (including the CDCA and other measures) were given to youths aged 11-15 in the three cultures. In one culture, youths received the questionnaire twice, to compute test-retest reliability.

RESULTS

The measure's reliability and validity were similar to those of other measures. The CDCA behaves similarly to the Revised Iowa Dental Control Index (R-IDCI). Youths in all three cultures showed similar responses, although the Japanese were less likely to endorse items.

STATISTICS

Internal reliability of the scale ranged from 0.74 to 0.85. Test- retest reliability was 0.74. Participants in the High Desire/Low Predicted classification on the R-IDCI scored higher on the CDCA (t (73) = 2.9, p < .01). In the Japanese and Australian samples the correlation between CDCA and dental fear was 0.29-0.33 (p < .001). The Australian and USA samples scored significantly higher than the Japanese sample (overall F(2,1544) = 383.98, p < .001, followed by Tukey's HSD, p < .001).

CONCLUSIONS

These results provide evidence for the reliability and validity of the CDCA in youth. It appears to measure the discrepancy between Desired and Predicted Control identified in the Revised Iowa Dental Control Index (R-IDCI). Responses of the youth in all three cultures were similar, indicating common dental control preferences for individuals of this age. However, consistent with cultural values, Japanese youth were less likely to endorse the control strategies. These results underline the need to develop culturally-specific, as well as situationally-specific control measures.

Gene therapy for haemophilia

Progress toward the development of a gene therapy protocol for the treatment of haemophilia has been substantial. Recent achievements include high level clotting factor expression in mice, dogs, and monkeys as well as phenotypic correction in both mouse and canine models of haemophilia. Studies using adenoviral vectors have contributed to much of the recent success. However, the repertoire of gene transfer vehicles being applied to the development of gene therapy strategies for haemophilia has expanded. In particular, encouraging data has been generated from studies using recombinant adeno-associated virus vectors. Progress toward human clinical trials has been inhibited by host immune responses to treatment which can limit the duration of therapy and prevent readministration. Several strategies have demonstrated the feasibility of circumventing host immune responses, but more effective, clinically applicable procedures remain to be developed. While direct in vivo gene therapy strategies have generated significant progress, the results from ex vivo strategies have not been as encouraging.

Incidence of occupational skin conditions in a food manufacturing company: results of a health surveillance programme

BACKGROUND

The food industry has been associated with a high risk of work-related skin problems. Aim To examine the incidence of work-related skin conditions and the likely causative agents in a single large food company.

METHOD

Analysis of a health surveillance programme, conducted over a 7 year period, in a food company with 21 000 employees working in diverse manufacturing processes.

RESULTS

The mean incidence of skin conditions, taking all of the different food manufacturing operations together, was 1310 per million employees per annum. The mean incidence was greatest in the manufacturing sector whose operations involved chilled or frozen product (3180 per million employees per annum). Most of the cases reported (184/192 = 96%) were due to primary irritant dermatitis. The two commonest suspected causes of the dermatitis were contact with ingredients and hand washing. Taken together, these factors accounted for 58% of all cases. Although the wearing of gloves is often considered necessary to prevent dermatitis from exposure to ingredients and to lessen the need for hand washing, this factor itself was responsible for 9% of all cases.

CONCLUSION

Analysis of a company health surveillance scheme showed the average incidence of work-related skin problems to be lower than previously reported in the food industry.

Preventing baker's asthma: an alternative strategy

BACKGROUND

Although baker's asthma has attracted considerable research interest over the last 30 years, success in its prevention has been slow to achieve. This paper describes the results of an alternative preventive strategy, based on an observation that the excess of sensitization in bread bakers is largely due to IgE-mediated allergy to fungal amylase, contained in bread improvers. The practical application of the strategy has been to limit bread improver exposures to <1 mg/m3 [8 h time-weighted average (TWA)], whilst exposures to all other ingredients, including flour, have been limited to <10 mg/m3 (8 h TWA).

METHOD

The paper describes the findings of in-house respiratory health surveillance and dust sampling programmes, from a UK food company whose primary interests are milling and baking, over the period following the introduction of the strategy to target the reduction in bread improver exposure.

RESULTS

Over the 10 year period of surveillance, the incidence of symptomatic sensitization in the bread baking sector (2240 per million employees per annum) was greater than for the other flour-using groups (330 per million employees per annum), despite broadly similar total inhalable dust exposures. There was an overall reduction in the incidence of new cases of symptomatic sensitization, from 2085 per million employees per year in the first 5 years of the surveillance programme, to 405 per million employees per year in the subsequent 5 years.

CONCLUSION

The strategy of targeting bread improver exposure is an effective approach for the prevention of new cases of symptomatic sensitization in bread bakeries.

Head and neck injuries in fatal motorcycle collisions as determined by detailed autopsy

Detailed layer-by-layer autopsy of the head and neck was performed on a prospective series of 73 fatally injured motorcyclists in order to identify occult injuries, particularly soft tissue neck injuries such as hemorrhage of vertebral and carotid arteries. The fatal cases were gathered as part of a larger study of 1,082 on-scene in-depth motorcycle crash investigations in Thailand. Detailed neck dissection was done on nearly all fatal cases. Injuries were coded using the 1990 revision of the Abbreviated Injury Scale (AIS 90) and an Injury Severity Score (ISS) was determined for each case. Additional AIS codes are proposed for neck injuries that were often identified during the detailed autopsy procedures, but which are not listed explicitly among existing AIS codes. Helmet use was determined based on analysis of injury patterns and helmet damage with consideration also given to witness statements. Both helmeted and unhelmeted motorcyclists showed a high frequency of occult neck injuries such as hemorrhages in the carotid sheath or surrounding the vertebral arteries, phrenic nerve, or brachial plexus. These soft tissue neck injuries sometimes accompanied more obvious injuries to cervical vertebrae or spinal cord, but about one-third of riders had no obvious injury to suggest the presence of occult neck injury. Twenty-eight motorcyclists had been wearing a helmet at the start of the collision sequence, but only nine helmets remained in place through the entire collision event. Helmeted riders showed more severe somatic (below-the-neck) injuries than unhelmeted riders, suggesting helmeted riders are less likely to die in low-threat accidents with somatic injuries below AIS-3. The most significant finding of this study was the identification of serious internal neck injuries despite the absence of external physical evidence of trauma to the neck. Virtually all riders with significant head injuries showed some of these soft tissue neck injuries. Approximately one-third of the critically injured riders who survived at least a few hours before death showed serious occult soft tissue neck injuries.

Head and neck injuries in fatal motorcycle collisions as determined by detailed autopsy

Detailed layer-by-layer autopsy of the head and neck was performed on a series of seventy-three fatally injured motorcyclists in order to identify occult soft tissue injuries such as subluxation of the cervical spine or hemorrhage of vertebral or internal carotid arteries. The fatal cases were gathered as part of a larger study of 1082 on-scene in-depth motorcycle crash investigations in Thailand. Injuries were coded using the 1990 Abbreviated Injury Scale (AIS 90) and an Injury Severity Score (ISS) was determined for each case. Twenty-eight motorcyclists had been wearing a helmet at the start of the collision sequence, but only nine helmets remained in place through the entire collision event. Both helmeted and unhelmeted motorcyclists showed a high frequency of neck injuries such as hemorrhages in the carotid sheath compressing the vagus nerve, hemorrhages surrounding the phrenic nerves or the brachial plexus, or hemorrhages surrounding the vertebral arteries. The most significant finding of this study was the identification of serious internal neck injuries even when there was no external physical evidence of trauma to the neck. Virtually all riders with significant head injuries showed some of these soft tissue neck injuries. This may be important for trauma physicians, who are presented with critically injured motorcyclists with complex multiple trauma, which may include occult soft tissue neck injuries.

University of Kentucky community-based field experience: program description

Community-based field experiences (CBFE) provide students with exemplary experiential learning opportunities. The purposes of this paper are to describe the University of Kentucky College of Dentistry (UKCD) CBFE and report the results of a two-year, self-report survey that assessed the primary course goal, students' perceptions of change in knowledge and skills related to nineteen areas of patient care (n = 90, 100% return rate), and their overall rating of the program. Knowledge and skill data were analyzed using the non-parametric binomial test for comparing proportions. A significant (.05 level) majority of students reported increases in knowledge in all areas to which they were exposed. Descriptive frequencies summarizing the results of the total CBFE experience indicate that the majority of students felt it was a positive experience. The CBFE continues to be a meaningful element in the UKCD curriculum as it provides students with a relevant, authentic educational experience.

Functionalized iminium salt systems for catalytic asymmetric epoxidation

A range of dihydroisoquinolinium salts containing alcohol, ether, and acetal functionalities in the nitrogen substituent has been prepared and tested as asymmetric epoxidation catalysts, providing ee's of up to ca. 60%.

Type A gamma-aminobutyric acid (GABAA) receptor subunits and benzodiazepine binding: significance to clinical syndromes and their treatment

Gamma (gamma)-aminobutyric acid (GABA) acting via GABAA receptors is the brain's major inhibitory neurotransmitter system and exerts a crucial role in regulating brain excitability. A number of drugs interact with binding sites on GABAA receptors, and these include benzodiazepines, anticonvulsants, anaesthetics and neurosteroids (e.g. the progesterone metabolite pregnalone). GABAA receptors comprise five subunits (19 are known currently), and are classified into three major groups (alpha, beta and gamma) and several minor ones. The subunit make-up of a receptor, particularly its alpha-subunit content, determines its pharmacological characteristics. Thus, receptors that include an alpha1 subunit have a benzodiazepine (BZ) type I (BZ[I]) pharmacology and bind zolpidem and CL218,872 with high affinity, whilst receptors with alpha2, alpha3 or alpha5 subunits have a BZ type II (BZ[II]) pharmacology and bind these drugs with low affinity. In contrast to receptors that contain alpha4 and alpha6 subunits, which are diazepam-insensitive, both BZ(I) and -(II) bind diazepam and other benzodiazepines. The ligand selectivity of receptor subunits assists in their characterisation. Using immunochemical and ligand-binding techniques, the subunit composition of GABAA receptors has been shown to exhibit a degree of brain regional specificity. GABAA receptors are of great clinical significance in several disorders, including epilepsy, anxiety and alcoholism. In addition to treating epilepsy with drugs that target GABAA and BZ binding sites, epileptic lesions can be localised presurgically using radiolabelled BZ ligands. BZs are used commonly to treat anxiety, and studies suggest that BZ antagonists and inverse agonists (which induce the opposite effect to agonists at receptors) may be useful in alcohol rehabilitation.

Pancreatic cancer presenting as bleeding gastric varices

Given the extremely poor prognosis of pancreatic adenocarcinoma, early diagnosis is crucial; however, clinical signs and symptoms of the disease are neither sensitive nor specific. In the two cases described, previously undiagnosed pancreatic cancers initially presented with upper gastrointestinal tract hemorrhage. Endoscopic surveys to identify the origin of the bleeding revealed gastric varices secondarily attributed to splenic vein thrombosis. Upon further investigation, the splenic vein occlusions were found to be caused by pancreatic tumors. A review of the incidence, pathogenesis, diagnostic modalities, and implications of splenic vein occlusion is included.

Child mortality and malaria transmission intensity in Africa

The desirability of controlling malaria transmission in the areas of highest endemicity of Plasmodium falciparum has long been debated. Most recently, it has been claimed that rates of malaria morbidity are no higher in areas of very high transmission in Africa than they are in places with lower inoculation rates. We now review the literature on the relationship of morbidity and mortality to malaria transmission intensity, and have linked published child mortality and malaria transmission rates to examine how age-specific mortality actually varies with the inoculation rate of P. falciparum.

Immunohistochemical analysis of anaplastic lymphoma kinase expression in deep soft tissue calcifying fibrous pseudotumor: evidence of a late sclerosing stage of inflammatory myofibroblastic tumor?

Calcifying fibrous pseudotumor (CFT) is a rare benign soft tissue lesion composed of dense hyalinized fibrous tissue containing bland spindle-shaped cells admixed with a lymphoplasmacytic infiltrate and foci of dystrophic and often psammomatous calcifications. It has been suggested that CFT represents a late sclerosing stage of inflammatory myofibroblastic tumor (IMT). Recently, clonal cytogenetic abnormalities involving the anaplastic lymphoma kinase (ALK) gene on chromosome 2p have been identified in IMT, particularly those arising in deep soft tissue sites. We evaluated seven cases of deep soft tissue CFT diagnosed at the Cleveland Clinic Foundation and the University of Florida with available paraffin-embedded blocks using a monoclonal antibody to ALK (Dako, Carpenteria, CA) and a modified avidin-biotin complex method. The cohort included six women and one man with a median age at diagnosis of 43 years (range, 26 to 67 years). Sites of CFT included mesentery (3), peritoneum (1), omentum (1), serosa of small bowel (1), and anterior mediastinum (1). Immunohistochemically, only one case showed focal staining for ALK. The remaining six cases were negative, with appropriate positive and negative control staining. In conclusion, unlike IMT, CFT in deep soft tissue locations rarely expresses ALK by immunohistochemistry, suggesting that CFT is a different clinicopathologic entity than IMT, as opposed to representing a "burned out" IMT. Ann Diagn Pathol 5:10-14, 2001.

Occupational skin conditions in the food industry

The study presents the findings of a questionnaire survey of skin conditions in a selective sample of the UK food industry, covering companies who employ occupational physicians. The mean incidence of skin conditions in food manufacturing operations was 2103 per million employees per annum. The mean incidence in retail or catering organizations was 1414 per million employees per annum.

Treatment of SW620 cells with Tomudex and oxaliplatin induces changes in 2-deoxy-D-glucose incorporation associated with modifications in glucose transport

Many studies suggest that changes in the uptake of the glucose analog FDG after therapy, compared with pretreatment uptake, predicts tumor response to therapy. However, clinical interpretation is compromised by a limited understanding of the effect of therapy on FDG and 2-deoxy-D-glucose (DG) uptake at the tumor cell level.

METHODS

Uptake of 2-deoxy-D-[1-(3)H]glucose (3H-DG) by SW620 colonic tumor cells was measured before and 8, 16, 24, and 48 h after treatment with the novel platinum drug oxaliplatin and the novel thymidylate synthase inhibitor Tomudex. Glucose transport was determined by measuring the initial rate of uptake of the nearly nonmetabolized glucose analog 3-O-methyl-D-[1-(3)H]glucose (3H-OMG). The effect of these drugs on cell cycle kinetics was determined using flow cytometry.

RESULTS

Treatment of SW620 cells with oxaliplatin was found to decrease uptake of 3H-DG after up to 24 h, but uptake returned to control levels after longer treatment. The initial decrease in 3H-DG incorporation was associated with a lower rate of glucose transport. Treatment of cells with Tomudex induced an increase in 3H-DG uptake that depended on treatment duration. Both glucose transport and the volume of distribution of 3H-OMG were higher in Tomudex-treated cells than in control cells. Flow cytometry showed that oxaliplatin induced a G2 and M arrest, whereas a buildup of cells in the S phase was associated with Tomudex treatment. Both treatments induced apoptosis in SW620 cells.

CONCLUSION

Changes in uptake of DG by SW620 colonic tumor cells responding to therapy is specific to the drug type. Modulation of glucose transport was associated with changes in 3H-DG uptake.

Identification of candidate endothelial cell autoantigens in systemic lupus erythematosus using a molecular cloning strategy: a role for ribosomal P protein P0 as an endothelial cell autoantigen

OBJECTIVE

To attempt to characterize the diversity and nature of antigens recognized by anti-endothelial cell antibodies (AECA) in patients with systemic lupus erythematosus (SLE) using a molecular cloning strategy.

METHODS

AECA in sera of 15 SLE patients were measured by ELISA and Western blot analysis was used to examine the diversity of autoantigen targets in two clinically active patients. A human umbilical vein endothelial cell cDNA expression library was immunoscreened with sera from these two patients to identify their autoantigen targets. An anti-ribosomal P peptide antibody ELISA was used to assess the clinical significance of anti-ribosomal P protein antibodies in the sera of one patient.

RESULTS

Significantly higher AECA levels were found in five patients with active disease and nephritis than in five patients with clinically inactive disease. Sera from two clinically active patients were found to recognize distinct spectra of autoantigens. The candidate autoantigens that were identified included (1) endothelial cell-specific plasminogen activator inhibitor; (2) the classical lupus antigen, i.e. ribosomal P protein P0; and (3) proteins never before described as putative autoantigens in SLE, including ribosomal protein L6, elongation factor 1alpha, adenyl cyclase-associated protein, DNA replication licensing factor, profilin II and the novel proteins HEAPLA 1 and HEAPLA 2 (human endothelial associated putative lupus autoantigens 1 and 2). In one patient, antibodies against ribosomal P protein P0 were predominant and levels of these antibodies correlated with total AECA levels, anti-DNA antibody titres, overall clinical score and renal disease in a longitudinal study.

CONCLUSIONS

A panel of candidate endothelial autoantigens in SLE, which includes previously described autoantigens and novel targets, has been identified by a molecular cloning strategy. This novel molecular approach could also be applied to the identification of autoantigens in other autoimmune vascular diseases.

[Prognosis in Guillain-Barre syndrome assessed by clinical and neurophysiological features]

The Guillain-Barrés' syndrome (GBS) is an acute inflammatory demyelinating polyradiculoneuropathy with a relatively low incidence and a relatively good prognosis. Patients with the axonal form of GBS often have a worse prognosis. Eleven patients who were unable to walk were analyzed clinically and with nerve conduction studies in the acute illness and at a follow-up 9-54 months. The first nerve conduction study characterized seven patients with demyelinating GBS and four with axonal GBS. At follow-up nine patients had no or minor symptoms and two had moderate symptoms. There was accordance between clinical and neurophysiological findings. Patients with axonal GBS had a worse prognosis. The incidence on the island of Fyn was 1.4 per 100,000.

Mammalian hexokinases and their abnormal expression in cancer

The phosphorylation of glucose, a crucial step in cellular metabolism, is catalysed by hexokinases (HK), of which there are four (HKI-IV) in mammalian tissues. The brain HK, (HK1), like HKII and HKIII, has a molecular weight of approximately 100 kDa. HKII is insulin-sensitive and found in adipose and muscle cells. HKIV, also known as glucokinase, has a molecular weight of 50 kDa and is specific to liver and pancreas. Most brain HK is bound to mitochondria via porins, enabling coordination between glucose consumption and oxidation. Tumour cells are known to be highly glycolytic, and correspondingly increased expression of glycolytic enzymes, including HK, have been detected in resected tumours from patients with lung, gastrointestinal and breast cancer. In the latter group, further increases in HK activity were associated with metastatic disease. Some studies have demonstrated increased HK activity in renal tumours, and also have reported changes in the isoenzymic expression of HK. Experimental studies of the initiation and progression of liver tumours have demonstrated a shift in expression from that of HKIV to HKI and HKII, with increased HK binding to mitochondria and a > 100-fold increase in HK activity. However, studies using xenografts derived from gliomas found decreased HK activity corresponding with loss of chromosome 10, the carrier of the HKI gene. Compared with normal tissues, a number of mechanisms are associated with changes in HK activity seen in tumours of the liver and other sites, and these include HK gene dosage, increased transcription, modulation of HK promoter activity by a broader range of effectors, and increased mitochondrial binding of HK. Increased HK activity, together with increased glucose transport by tumour cells, has been exploited in cancer imaging using the positron-labelled glucose analogue (18F)fluoro-2-deoxy-D-glucose (FDG), which is transported into cells and then phosphorylated, but undergoes little further metabolism. Accumulated FDG then can be detected using positron emission tomography (PET).

Use of abdominal ultrasonography in the diagnosis of primary hyperaldosteronism in a cat

A 13-year-old castrated male cat was examined because of a 2-week history of weakness, cervical ventroflexion, and dysphagia. Clinicopathologic abnormalities included hypokalemia and high serum creatine kinase activity. Abdominal ultrasonography revealed a 15-mm spherical mass in the area of the left adrenal gland. Plasma aldosterone concentration was high, and plasma renin activity was low. Findings were diagnostic of primary hyperaldosteronism. The cat responded well to intravenous and oral potassium supplementation while in the hospital. The owner declined surgery; therefore, repeated follow-up abdominal ultrasonography was recommended. The cat did well clinically with medical management alone until day 334, when it was lost to follow-up.

Heritability and segregation analysis of immune responses to specific malaria antigens in Papua New Guinea

Familial patterns of inheritance of immune responses to specific Plasmodium falciparum antigens were studied in 214 adults in an area of Papua New Guinea highly endemic for malaria. Preliminary variance component analysis indicated familial aggregation in both humoral and cellular immune responses against the ring-infected erythrocyte surface antigen (RESA) and the FC27 allele of the Merozoite surface antigen 2 (MSA-2). Including a term for sharing houses in the models affected only the antibody response to RESA. Segregation analysis of the antibody responses against RESA indicated inheritance via a multifactorial model and analysis of the proliferation response suggested a possible recessive major gene. The best fitting models for the immune responses against MSA-2 (FC27) postulated dominant major gene inheritance. We found no significant associations between HLA class I or II alleles and these two antigens in this population. Although there was evidence of familial aggregation of antibody responses to MSA-2 (3D7), the segregation analysis failed to identify a mode of inheritance. There was little or no heritability of either humoral or cellular immune responses against the NANP repeats of the Circumsporozoite protein (NANP), the synthetic malaria vaccine SPf66, or a preparation of MSA-2 (3D7) from which the repetitive part was deleted (MSA-2 (d3D7)). Although it is often difficult to separate genetic effects from the effects of living in the same environment, it appears that some immune responses against certain malaria antigens may be partly influenced by genetic factors.

The influence of a workshop on dental students' perceptions about sexual harassment

The objective of this study was to determine the effects of a workshop on the sexual harassment perceptions of students at the University of Kentucky College of Dentistry. Responses to a twenty-six-item questionnaire were elicited from 147 first-through fourth-year students before and after they attended a two-hour sexual harassment workshop. Five questions explored students' personal experiences with sexual harassment; twenty-one questions addressed students' attitudes about sexual harassment. The repeated measures option of the SPSS General Linear Model statistical program was used to individually analyze the Likert-type scale response to the twenty-one attitude items for the following variables: gender, year in dental education, and whether respondents had been sexually harassed or had observed harassment of others. Workshop participation significantly changed some student attitudes about sexual harassment regardless of gender, year in dental education, or whether they had been harassed personally or had witnessed harassment of someone else (p < .05). There were also significant gender-related differences in the direction and magnitude of change in pre- versus post-workshop responses to several attitude items (p < .05). Workshop participants were better informed about and more sensitive to a wide range of sexual harassment issues. The workshop empowered students, especially females, to help create an environment that minimizes the probability of sexual harassment. This may be possible because, after the workshop, participants better understood institutional policies and procedures to handle complaints, including provisions for protection from retaliation if they do file a grievance. This knowledge and sensitivity may result in an environment that facilitates the education of beginning general practitioners who are competent, empathetic, and sensitive.

A survey of resident selection procedures in oral and maxillofacial surgery

PURPOSE

This study was conducted to analyze the current procedures used in oral and maxillofacial surgery resident selection, to compare these selection procedures with those used 2 decades ago, to determine whether any differences exist in the selection procedures between 4-year certificate programs and programs that offer formal medical education, and to provide criteria to assist in the counseling of dental students on the application process for oral and maxillofacial surgery residencies.

SUBJECTS AND METHODS

Questionnaires were sent to the 106 oral and maxillofacial surgery graduate training programs accredited by the American Dental Association. To provide for a more direct comparison to the study completed in 1976, the current questionnaire was developed, using the original survey as a model. It was divided into 5 sections: general information, information obtained from the formal application and letters of recommendation, the interview, the decision process, and a retrospective view of past decisions. The results were tabulated and the Pearson chi-square test was used to determine statistical significance when comparing the 4-year certificate programs to the programs that offer formal medical education.

RESULTS

Seventy-one responses (75.5%) from nonmilitary programs were returned and analyzed. Thirty-nine responses represented dual-degree (MD) programs. Factors that were considered very important when judging a candidate's written application included dental school class rank (76.1%), dental school basic science grades (70.4%), and dental school clinical grades (63.4%). Dual-degree programs placed a greater emphasis on predental basic science grades (P < .01) and dental national board scores (P < .05). When asked about prior resident selection, 86.7% of the respondents said they would select 80% of their former residents again. In addition, 89.9% of the respondents were satisfied with their current selection process.

CONCLUSIONS

The procedures used to select oral and maxillofacial surgery residents are relatively constant among programs. Although the dual-degree and 4-year certificate programs use the same criteria for resident selection, the dual-degree programs place greater emphasis on predental academic performance and on the results of the national dental boards. Criteria used 22 years ago to select residents are still applicable, but there has been a shift in the importance of some variables.

Assessment of different sources of variation in the antibody responses to specific malaria antigens in children in Papua New Guinea

BACKGROUND

A potential problem for malaria vaccine development and testing is between-host variation in antibody responses to specific malaria antigens. Previous work in adults in an area highly endemic for Plasmodium falciparum in Papua New Guinea found that genetic regulation partly explained heterogeneity in responsiveness. We have now assessed the relative contributions of environmental and genetic factors in total IgG responses to specific malaria antigens in children, and quantified temporal variation within individuals of total IgG responses.

METHODS

Total IgG responses against schizont extract, merozoite surface protein-1, merozoite surface protein-2, ring-infected erythrocyte surface antigen, and SPf66 were measured by ELISA. Variance component analysis was used to estimate the variation explained by genetic and environmental factors in these antibody responses. Intra- and inter-class correlations of antibody responses within relative pairs were estimated. We adjusted for age, P. falciparum density, sex and village differences either within or prior to the analysis.

RESULTS

For all malaria antigens, temporal variation in the total IgG response was the predominant source of variation. There was substantial familial aggregation of all IgG responses, but it remained unclear how much this clustering was attributable to genetic factors and how much to a common environment in the household. The remaining variance, which could not be explained by either of the above, was very small for most of the antigens.

CONCLUSIONS

Temporal variation and clustering of immune responses to specific malaria antigens need to be taken into account when planning, conducting and interpreting immuno-epidemiological and vaccine studies.

Facilitative glucose transporter expression in human cancer tissue

Glucose utilisation by cancer cells is greatly enhanced when compared with that by normal tissue. Glucose is taken up by cells and then phosphorylated to glucose-6-phosphate. Facilitative hexose uptake is achieved by five transmembrane transporters, termed glut1-5, which are protein products of their respective GLUT genes. Glut types differ in their kinetics, which are tailored to the requirements of the cell type they serve, although more than one glut may be expressed by a particular cell type. Herein are reviewed the results from approximately 30 studies which examined glut expression in human cancer tissue. These studies measured GLUT messenger RNA (mRNA) either using the reverse-transcriptase polymerase chain reaction or by Northern blot analysis, or detected glut proteins using the appropriate antibodies. Tumour tissue is frequently associated with the abnormal and/or over-expression of gluts, especially glut1. Some tumour cells express specific GLUT mRNA but not the respective protein. Some studies have reported associations between glut expression and proliferative indices, whilst others suggest that glut may be of prognostic significance, especially in lung cancer.

Deoxyglucose uptake by a head and neck squamous carcinoma: influence of changes in proliferative fraction

PURPOSE

Positron emission tomography, using the glucose analogue fluorodeoxy-D-glucose (FDG), is proving to be useful in the early response detection of head and neck tumors. Presently mechanisms underlying changes in FDG uptake after therapy are poorly understood. Response of tumors to therapy is often accompanied by a decrease in tumor cell proliferation. The purpose of this study was to assess whether or not changes in the uptake of deoxyglucose (DG) may reflect differences in proliferative fraction independent of other metabolic changes induced by using therapeutic agents.

METHODS AND MATERIALS

HN5 head and neck tumor cells were grown to different cell densities producing populations of cells with different proliferative indices without the need for exogenous agents to manipulate cell-cycle kinetics. (3)H-DG uptake, S-phase fraction (Spf), and lactate production were determined in each population of cells.

RESULTS

Large differences in Spf between populations of cells were associated with differences in DG incorporation. Lactate production was also found to correlate strongly with DG uptake.

CONCLUSION

Therapy-induced changes in FDG uptake by tumors may be partly due to changes in proliferation.

Optimized MR imaging for polyacrylamide gel dosimetry

Polyacrylamide gels are a powerful tool to measure radiation dose by quantifying the NMR T2 relaxation times of the irradiated gel. The exploitation of these radiation sensitive gels in clinical radiotherapy requires accurate mapping of T2 values. This paper describes the optimization strategy used to identify accurate and practical methods of measuring the range of T2 values typical of gel dosimeters (140-700 ms). The MR imaging techniques used to measure T2 values and the choice of image acquisition parameters are described. Four sequences are compared and the results are analysed in terms of accuracy, signal-to-noise ratio and acquisition time. A multiple spin echo sequence was found to yield the most accurate results (98.9%). Single spin echo sequences, such as Hahn spin echo and EPI spin echo, were found to measure gel T2 values with an accuracy of 90.1%. This paper reports the importance of careful selection and optimization of the MR imaging sequences for accurate and reliable polyacrylamide gel dosimetry.

Genetic analysis of IgG subclass responses against RESA and MSP2 of Plasmodium falciparum in adults in Papua New Guinea

Contributions of environmental and genetic factors to IgG subclass responses against Plasmodium falciparum antigens RESA and MSP2 were investigated among adults in a highly endemic area of Papua New Guinea. Heritabilities were estimated using variance component analysis. Familial aggregation of several responses was found, including IgG1, IgG2 and IgG3 responses against RESA, IgG1 and IgG3 responses against the 3D7 form of MSP2 and IgG1, IgG2 responses against the FC27 form of MSP2. Allowance for sharing of houses explained some of the non-genetic variance but not the familial aggregation. The variance of IgG3 responses against RESA and IgG1, IgG2 against MSP2 (FC27) was partly explained by sharing of HLA class II genotypes, although heritability was low. Segregation analyses indicated that any genetic regulation was more complex than governed by a single major gene. Such host genetic variation in responses to specific malaria antigens has implications for immuno-epidemiology and vaccine development.

Respiratory symptoms and wheat flour exposure: a study of flour millers

The objective of this study was to determine the prevalence of respiratory symptoms and their relationship to sensitization to wheat flour allergens and fungal amylase, in a group of workers from the UK flour milling industry. A cross-sectional study was used to evaluate symptoms, using a structured interview technique, and sensitization, using skin prick test findings, from 679 employees in flour milling and packing operations at 18 flour mills. A total of 147 workers (147/679, 22%) described upper respiratory tract symptoms of some kind. In the majority (139/147, 95%) these symptoms were of an occasional or transitory nature and were related to short-term exposures to high levels of dust. Three individuals (3/679, 0.4%) were identified whose symptoms were thought to be the result of allergy to wheat flour. The prevalence of positive skin prick tests to wheat flour allergens and to fungal amylase was 1.2% (8/678) and 0.9% (6/678), respectively. Measurements of total inhalable dust exposure for personnel exposed to flour dust were taken at 10 of the sites (116 samples). For production personnel the levels were typically between 1 and 10 mg/m3 (8-h time weighted average), with a median of 6.2 mg/m3. Hygiene operatives had appreciably higher exposure than production personnel, with a median of 18.7 mg/m3. Overall, 43% (50/116) of all samples exceeded 10 mg/m3 (8-h time weighted average). The findings suggest that the risk of sensitization to wheat flour allergens from current dust exposures in flour mills is very low. Wheat allergy was responsible in only a small proportion of the total who had respiratory symptoms. The principal causation of symptoms experienced by the workforce was considered to be a non-specific irritant effect related to short-term exposures to high levels of total inhalable dust.

RWMODEL II: computer simulation of the Rescorla-Wagner model of Pavlovian conditioning

RWMODEL II simulates the Rescorla-Wagner model of Pavlovian conditioning. It is written in Delphi and runs under Windows 3.1 and Windows 95. The program was designed for novice and expert users and can be employed in teaching, as well as in research. It is user friendly and requires a minimal level of computer literacy but is sufficiently flexible to permit a wide range of simulations. It allows the display of empirical data, against which predictions from the model can be validated.

Usefulness of cytokeratin subsets for distinguishing monophasic synovial sarcoma from malignant peripheral nerve sheath tumor

Monophasic synovial sarcoma (MSS) and malignant peripheral nerve sheath tumor (MPNST) are spindle cell sarcomas with overlapping histologic features, and their immunophenotypes may overlap, since MPNSTs express S-100 protein in only 50% to 60% of cases and rarely express epithelial markers, whereas MSSs can express S-100 protein in up to 40% of cases. We immunostained 29 cases of MSS and 29 cases of MPNST with antibodies to AE1/AE3, CAM 5.2, epithelial membrane antigen (EMA), S-100 protein, and cytokeratin subsets 7 and 19. Inclusion criteria for MSS included a consistent histology with expression of at least 1 epithelial marker. Inclusion criteria for MPNST included a tumor with a consistent histology arising in a patient with neurofibromatosis type 1 and/or in a plexiform neurofibroma, or ultrastructural confirmation of clear-cut schwannian differentiation. By definition, all cases of MSS were positive for at least 1 epithelial marker. Ten cases showed focal S-100 protein immunoreactivity, and 26 cases stained for cytokeratins 7 and 19. Twenty-three cases stained for both antigens, whereas only 2 cases were negative for both cytokeratins. Twenty-two MPNSTs demonstrated immunoreactivity for S-100 protein, and 11 stained focally for AE1/AE3 or EMA. Two cases of MPNST stained for cytokeratin 7, and only 1 case stained for cytokeratin 19. No cases of MPNST stained for both cytokeratins. Antibodies to cytokeratins 7 and 19 are useful adjuncts for the separation of MSS from MPNST. The majority of MSSs stain for one or both of these antigens, whereas most MPNSTs, including those that are EMA- or AE1/AE3-positive, do not express these cytokeratin subsets.

Analysis of the latency-associated transcript/UL1-3.5 gene cluster promoter complex of pseudorabies virus

During latency, pseudorabies virus (PRV) DNA is preferentially retained in the neurons of the trigeminal ganglion and a spliced 8.5-kilobase poly-A RNA, designated large latency transcript (LLT), is synthesized. Because LLT is the only transcript made during the latent phase, the LLT promoter may be unique among all other PRV promoters that are active in productive infections. Organization of the PRV LLT promoter is quite complex because it coincides with the UL1-3.5 gene cluster promoter, but in the opposite orientation. By conventional designation, LLT is transcribed in the rightward direction while the UL1-3.5 gene cluster is transcribed in the leftward orientation. In this work, activities of the LLT promoter and the UL1-3.5 gene cluster promoter were investigated by transient reporter gene expression assay in cells of neuronal and non-neuronal origins. There are two TATA boxes in this region. We examined the promoter activities of the first TATA box with its 5' sequence (LAP1) and the second TATA box with its 5' sequence (LAP2). The UL1-3.5 promoter driven constructs gave no reporter gene activity in any of the experiments. Reporter gene activity was detected with LAP2 gene constructs, but not with LAP1 constructs, in both neuronal and non-neuronal cells. This is surprising because transcription of PRV LLT in vivo has been attributed to LAP1 and the initiation site was mapped downstream of the LAP1 TATA box and upstream of the LAP2 TATA box. Although LAP1 was not active in these experiments, there was a 3- to 10-fold enhancement of activity when LAP1 and LAP2 were placed in tandem.