Bilateral accessory flexor indicis muscle: A case study

Muscular variations within the upper extremities are common and widely documented. They can have a range of implications including nerve compression and misdiagnosis but are often silent. Our report herein describes a bilateral accessory muscle found in the forearm during routine cadaveric dissection. The muscle originates from the medial epicondyle of the humerus between the origins of the flexor digitorum superficialis and flexor carpi radialis muscles. The muscle is digastric, with the distal belly existing as the first lumbrical and the proximal serving as a supernumerary flexor. This functionally atavistic variation could prove clinically relevant for the purposes of donor muscle or tendon tissue as well as surgical complications and compressive neuropathies.

Background levels of body fluids and DNA on the shaft of the penis and associated underpants in the absence of sexual activity

This study examines the background of blood, saliva, semen and autosomal DNA on penile swabs and underpants from males in the absence of recent sexual activity. Based on the data collected by the AFSP Body Fluid Forum, the results of this study show that; there is a very low expectation of detecting blood on penile swabs and male underpants; a low expectation of detecting saliva on penile swabs and male underpants; and spermatozoa would be expected in less than a quarter of penile swabs and three quarters of male underpants. As none of the samples had detectable levels of DNA which were suitable for meaningful comparison that did not match the donor or their partner, the expectation of detecting a DNA profile from the cellular background on penile swabs or underpants from a male who has not been involved in recent sexual intercourse is very low. The results of this study are extremely informative when evaluating the significance of blood, saliva, semen and DNA detected on the penile swabs and underpants of males in cases of alleged sexual assault.

The relevance of false positive acid phosphatase reactions indicative of the presence of seminal fluid from oral and vaginal samples

The Body Fluid Forum of the Association of Forensic Science Providers recognised concerns raised by forensic practitioners regarding the lack of data to inform on the incidence of significant AP (Acid Phosphatase) reactions from vaginal and oral samples, i.e. those which might be misinterpreted as indicating the presence of semen. This is particularly relevant in the light of appeal court rulings regarding the need for data to support evaluations. This paper presents collaborative data on the nature and incidence of AP reactions from vaginal and oral swabs provided by donors. The results demonstrate that caution is required with mid to strong purple AP reactions from direct testing of oral swabs and with mid purple reactions from vaginal swabs. The use of a Bayesian approach to assist with the provision of opinions regarding the presence of seminal fluid is highlighted.

Polygenic Risk Scoring is an Effective Approach to Predict Those Individuals Most Likely to Decline Cognitively Due to Alzheimer's Disease

BACKGROUND

There is a clear need for simple and effective tests to identify individuals who are most likely to develop Alzheimer's Disease (AD) both for the purposes of clinical trial recruitment but also for improved management of patients who may be experiencing early pre-clinical symptoms or who have clinical concerns.

OBJECTIVES

To predict individuals at greatest risk of progression of cognitive impairment due to Alzheimer's Disease in individuals from the Alzheimer's Disease Neuroimaging Initiative (ADNI) using a polygenic risk scoring algorithm. To compare the performance of a PRS algorithm in predicting cognitive decline against that of using the pTau/Aß1-42 ratio CSF biomarker profile.

DESIGN

A longitudinal analysis of data from the Alzheimer's Disease Neuroimaging Initiative study conducted across over 50 sites in the US and Canada.

SETTING

Multi-center genetics study.

PARTICPANTS

515 subjects who upon entry to the study were diagnosed as cognitively normal or with mild cognitive impairment.

MEASUREMENTS

Use of genotyping and/or whole genome sequencing data to calculate polygenic risk scores and assess ability to predict subsequent cognitive decline as measured by CDR-SB and ADAS-Cog13 over 4 years.

RESULTS

The overall performance for predicting those individuals who would decline by at least 15 ADAS-Cog13 points from a baseline mild cognitive impairment in 4 years was 72.8% (CI:67.9-77.7) AUC increasing to 79.1% (CI: 75.6-82.6) when also including cognitively normal participants. Assessing mild cognitive impaired subjects only and using a threshold of greater than 0.6, the high genetic risk participant group declined, on average, by 1.4 points (CDR-SB) more than the low risk group over 4 years. The performance of the PRS algorithm tested was similar to that of the pTau/Aß1-42 ratio CSF biomarker profile in predicting cognitive decline.

CONCLUSION

Calculating polygenic risk scores offers a simple and effective way, using DNA extracted from a simple mouth swab, to select mild cognitively impaired patients who are most likely to decline cognitively over the next four years.

DNA transfer through nonintimate social contact

The UK and Ireland Association of Forensic Science Providers' (AFSP) Body Fluid Forum (BFF) set out to assist in the interpretation of sexual offence cases where semen is absent on vaginal swabs but female DNA is present on penile swabs or male underwear, and the issue to be addressed is whether or not sexual intercourse occurred. This study aims to investigate the frequency and amount of female DNA transferred to the penis and underwear of males following staged nonintimate social contact with females and to compare the findings with the amount of female DNA transferred to the penis and subsequently to the underwear of a male who had engaged in unprotected sexual intercourse with a female. In this study, no matching female DNA was detected on the inside front of the 44 items of male underwear used in this research following staged contact of a nonintimate nature and subsequent secondary transfer to the penis. After sexual intercourse, full profiles matching the female participant were found on the inside front of the males underwear with maximum peak heights in the range between 1898 and 3157 rfu. It was possible to demonstrate that DNA can occasionally transfer to the waistband and outside front of underwear worn by a male following staged nonintimate social contact. Data obtained in this study suggest that a matching female DNA profile below a peak height of 1000 rfu on the waistband of a male's underwear might be explained by nonintimate social contact with secondary transfer of female DNA from the male's hands.

CD44 functions in Wnt signaling by regulating LRP6 localization and activation

Wnt reception at the membrane is complex and not fully understood. CD44 is a major Wnt target gene in the intestine and is essential for Wnt-induced tumor progression in colorectal cancer. Here we show that CD44 acts as a positive regulator of the Wnt receptor complex. Downregulation of CD44 expression decreases, whereas CD44 overexpression increases Wnt activity in a concentration-dependent manner. Epistasis experiments place CD44 function at the level of the Wnt receptor LRP6. Mechanistically, CD44 physically associates with LRP6 upon Wnt treatment and modulates LRP6 membrane localization. Moreover, CD44 regulates Wnt signaling in the developing brain of Xenopus laevis embryos as shown by a decreased expression of Wnt targets tcf-4 and en-2 in CD44 morphants.

Evaluation of the effect of orally administered acid suppressants on intragastric pH in cats

Background

Acid suppressant drugs are a mainstay of treatment for cats with gastrointestinal erosion and ulceration. However, clinical studies have not been performed to compare the efficacy of commonly PO administered acid suppressants in cats.

Hypothesis/Objectives

To compare the effect of PO administered famotidine, fractionated omeprazole tablet (fOT), and omeprazole reformulated paste (ORP) on intragastric pH in cats. We hypothesized that both omeprazole formulations would be superior to famotidine and placebo.

Animals

Six healthy adult DSH colony cats.

Methods

Utilizing a randomized, 4‐way crossover design, cats received 0.88–1.26 mg/kg PO q12h fOT, ORP, famotidine, and placebo (lactose capsules). Intragastric pH monitoring was used to continuously record intragastric pH for 96 hours beginning on day 4 of treatment. Plasma omeprazole concentrations at steady state (day 7) were determined by high performance liquid chromatography (HPLC) with ultraviolet detection. Mean percentage time that intragastric pH was ≥3 and ≥4 were compared among groups using ANOVA with a posthoc Tukey‐Kramer test (α = 0.05).

Results

The mean percentage time ± SD that intragastric pH was ≥3 was 68.4 ± 35.0% for fOT, 73.9 ± 23.2% for ORP, 42.8 ± 18.6% for famotidine, and 16.0 ± 14.2% for placebo. Mean ± SD plasma omeprazole concentrations were similar in cats receiving fOT compared to those receiving ORP and in a range associated with acid suppression reported in other studies.

Conclusions and Clinical Importance

These results suggest that both omeprazole formulations provide superior acid suppression in cats compared to famotidine or placebo. Fractionated enteric‐coated OT is an effective acid suppressant despite disruption of the enteric coating.

Esophageal impedance baselines in infants before and after placebo and proton pump inhibitor therapy

BACKGROUND

Esophageal impedance monitoring records changes in conductivity. During esophageal rest, impedance baseline values may represent mucosal integrity. The aim of this study was to assess the influence of acid suppression on impedance baselines in a placebo-controlled setting.

METHODS

Impedance recordings from 40 infants (0-6 months) enrolled in randomized placebo-controlled trials of proton pump inhibitor (PPI) were retrospectively analyzed. Infants underwent 24 h pH-impedance monitoring prior to and after 2 weeks of double blind therapy with placebo or a PPI. Typical clinical signs of gastro-esophageal reflux (GER) were recorded and I-GERQ-R questionnaire was completed.

KEY RESULTS

Median (IQR) impedance baseline increased on PPI treatment (from 1217 (826-1514) to 1903 (1560-2194) Ω, P < 0.001) but not with placebo (from 1445 (1033-1791) to 1650 (1292-1983) Ω, P = 0.13). Baselines before treatment inversely correlate with the number of GER, acid GER, weakly acid GER, acid exposure, and symptoms. The change in baseline on treatment inversely correlates with acid exposure and acid GER. Patients with initial low baselines have no improved symptomatic response to treatment.

CONCLUSIONS & INFERENCES

Impedance baselines are influenced by GER and increase significantly more with PPI therapy than with placebo. Clinical impact of this observation remains undefined as targeting therapy at infants with low baselines does not improve symptomatic response to treatment.

Development of pharyngo-esophageal physiology during swallowing in the preterm infant

BACKGROUND

Poor feeding is a common cause of prolonged hospitalization of preterm infants. Pharyngeal and upper esophageal sphincter (UES) function of preterm infants has been technically difficult to assess and is therefore poorly characterized. The aim of this study was to assess the development of pharyngeal motility, UES function, and their coordination during nutritive swallowing in preterm infants.

METHODS

Development of swallowing was assessed in 18 preterm infants. High resolution manometry was performed at first oral feeding attempt (31-32 week) and then weekly for 4 weeks. Pharyngeal and UES pressure changes were characterized in 980 swallows.

KEY RESULTS

During swallowing, we observed an age-related increase in peak pharyngeal pressure at the laryngeal inlet (1 cm above UES) but an age-related decrease in the time required for the UES to fully relax to nadir. Analysis of the timing of proximal pharyngeal contractile peak and UES nadir showed that the UES was not fully relaxed when bolus propulsive forces were at their peak in the youngest infants.

CONCLUSIONS & INFERENCES

Results show developmental changes in infant swallow physiology that can be clearly linked to the effectiveness of nutritive swallowing. Most preterm infants demonstrated poor pharyngeal pressures at the laryngeal inlet coupled with poor coordination of pharyngeal propulsion with UES relaxation. These pressure patterns were less efficient than those demonstrated by older infants who were more adept at feeding. These observations may explain why infants under 34 weeks are physiologically unable to feed effectively and experience frequent choking and fatigue during feeding.

Pharyngeal flow interval: a novel impedance-based parameter correlating with aspiration

BACKGROUND

The role of pharyngeal impedance recording for assessing pharyngeal function is yet to be established. The aim of this study was to evaluate impedance flow interval, a novel parameter, in relation to bolus residue and the occurrence of aspiration. The effect of catheter configuration was also assessed.

METHODS

We studied 12 children (1.8-13.5years) with cerebral palsy, who were all referred for a videofluoroscopy due to suspected aspiration risk. Pharyngeal impedance patterns during bolus swallowing were recorded simultaneously with fluoroscopy. Two different catheter configurations were used: Catheter 1, 1.9mm diameter with 1cm electrodes and Catheter 2, 3.2mm diameter with 2cm electrodes. The flow interval was based on the objective assessment of impedance drop and recovery across multiple impedance segments and was correlated with fluoroscopic evidence of postswallow bolus residue and deglutitive aspiration.

KEY RESULTS

One hundred and thirty two liquid swallows were evaluated. Patient swallows with aspiration compared to those without aspiration had a longer flow interval (Cath 1 P=0.005; Cath 2 P<0.001). Patient swallows with residue had a longer flow interval, however this was only significant for swallows recorded using Catheter 2 (P=0.004). Multiple logistic regressions showed that higher flow interval was a better marker of the presence of aspiration [odds ratio (OR) 13.4 (3.0, 59.2); P<0.001] than the presence of residue [OR 3.8 (1.4, 10.3); P=0.01].

CONCLUSIONS & INFERENCES

We present novel findings suggesting that impedance measurement can detect alterations in flow characteristics of pharyngeal swallow that have the potential to predict to deglutitive aspiration risk.

Efficacy of oral famotidine and 2 omeprazole formulations for the control of intragastric pH in dogs

BACKGROUND

Little is known about the efficacy of commonly used acid suppressants on intragastric pH in dogs.

OBJECTIVE

To compare the effect of oral famotidine, 2 formulations of omeprazole, and placebo on intragastric pH in dogs with a catheter-free, continuous pH monitoring system.

ANIMALS

Six healthy adult mixed-breed colony dogs.

METHODS

Utilizing a randomized, 4-way cross over, open-label study, dogs were administered famotidine PO (1.0-1.3 mg/kg q12h), omeprazole tablet (1.5-2.6 mg/kg q24h), omeprazole reformulated paste (RP) (Gastrogard, 1.5-2.6 mg/kg q24h), and placebo for 7 days followed by a 10-day washout period. Radiotelemetric pH capsules were placed with gastroscopy assistance to continuously record intragastric pH for 4 days (days 4-7 of dosing). The percentage of time that intragastric pH was ≥3 and ≥4 was compared among treatment groups using repeated measures of analysis of variance. Tukey's Studentized range test was used to determine which groups were different with α= 0.05.

RESULTS

Mean ± SD percent time intragastric pH was ≥3 and ≥4 was 22 ± 8% and 14 ± 6% for famotidine, 63 ± 14% and 52 ± 17% for omeprazole tablet, 54 ± 17% and 44 ± 18% for omeprazole RP, and 6 ± 6% and 5 ± 5% for placebo. Both omeprazole formulations significantly increased intragastric pH compared with famotidine and placebo, but omeprazole tablet and RP was not significantly different from each other.

CONCLUSION

Oral omeprazole tablet and RP provide superior gastric acid suppression to famotidine, and should therefore be considered more effective for the treatment of acid related disorders in dogs.

Collagen type III alpha I is a gastro-oesophageal reflux disease susceptibility gene and a male risk factor for hiatus hernia

BACKGROUND AND OBJECTIVES

Gastro-oesophageal reflux disease (GORD) is a common gastrointestinal disorder with a genetic component. Our aim was to identify genetic factors associated with GORD.

PATIENTS AND METHODS

Four separate patient cohorts were analysed using a step-wise approach. (1) Whole genome linkage analysis was performed in 36 families. (2) Candidate genes were tested for GORD association in a trio cohort. (3) Genetic association was replicated in a case-control cohort. We also investigated genetic association to hiatus hernia (HH). (4) Protein expression was analysed in oesophageal biopsies.

RESULTS

A region on chromosome 2, containing collagen type III alpha 1 (COL3A1), was identified (LOD = 3.3) in families with dominant transmission of GORD, stratified for hiatus hernia (HH). COL3A1 showed significant association with GORD in an independent paediatric trio cohort (p(corr) = 0.003). The association was male specific (p(corr) = 0.018). The COL3A1 association was replicated in an independent adult case control cohort (p(corr) = 0.022). Moreover, male specific association to HH (p(corr) = 0.019) was found for a SNP not associated to GORD. Collagen type III protein was more abundant in oesophageal biopsies from male patients with GORD (p = 0.03).

CONCLUSION

COL3A1 is a disease-associated gene in both paediatric and adult GORD. Furthermore, we show that COL3A1 is genetically associated with HH in adult males. The GORD- and HH-associated alleles are different, indicating two separate mechanisms leading to disease. Our data provides new insight into GORD aetiology, identifying a connective tissue component and indicating a tissue remodelling mechanism in GORD. Our results implicate gender differences in the genetic risk for both for GORD and HH.

Characterization of intraluminal impedance patterns associated with gas reflux in healthy volunteers

Multichannel intraluminal impedance (MII) recording allows assessment of flow through the oesophagus and differentiation between liquid and gas contents. Existing MII criteria for recognition of gas gastro-oesophageal reflux (GOR) have not been validated during known gas GOR in humans.

AIMS

(i) Characterize MII patterns of known gas GOR and optimize criteria. (ii) Clarify interrelationships between magnitude of maximal impedance change, luminal diameter and electrode-mucosa contact. Ten healthy volunteers (six male, 21-37 years) were studied using an oesophageal MII-manometry catheter. After catheter placement, subjects were asked to drink 600 mL of carbonated soft drink. Recordings were made for 20 min and the protocol repeated. Reported belches confirmed manometrically (triggered by transient lower oesophageal sphincter relaxations) were included for analysis. Those episodes were compared against commonly used criteria. Another five subjects (three male, 26-52 years) underwent simultaneous MII and videofluoroscopy using the same protocol. Videofluoroscopic images were analyzed for luminal diameter and the presence of electrode-mucosa contact. All analyzed gas GOR episodes (n = 88) were associated with a pattern of impedance rise which was either retrograde (62.5%), synchronous (19.3%) or antegrade (18.2%). Depending on the exact criteria used, sensitivity ranged from 33% to 75%. A multivariate regression model including luminal diameter and the presence of electrode-mucosa contact as independent factors accounted for 53% of all variation in impedance changes. In conclusion, a significant number of gas GOR episodes does not meet criteria for their recognition. New criteria are proposed to include specific antegrade patterns of impedance rise. Luminal diameter and the extent of contact between the oesophageal mucosa and MII-electrodes influence the magnitude and patterning of impedance change.

Detection of treatable neonatal liver disease by expanded newborn screening

Two neonates were identified at age 48 h by expanded newborn screening, with abnormal methionine and tyrosine concentrations, which were confirmed on repeat samples. Evidence of previously unsuspected liver disease was found at recall, and there was radiological and biochemical evidence of severe liver disease with hepatic synthetic failure. After inborn errors of metabolism (IEMs) were excluded, both were considered to have neonatal haemochromatosis, on the basis of raised ferritin, iron saturation, and very high α-fetoprotein and confirmed by a mildly hyperferritinaemic sibling in the first case, and raised ferritin and iron saturation in the second. However, it was not feasible to obtain tissue confirmation as the requirement for early therapy precluded biopsy. The babies were treated with antioxidants and iron-chelating agents, and the coagulopathy and hypoalbuminaemia were corrected. Both made a complete recovery and remain well after follow-up. Newborn screening programmes could consider advising clinicians, when tyrosine and methionine values are elevated, that once IEMs are excluded liver disease from other causes must be sought. Neonatal haemochromatosis is an example of one such disease that is potentially treatable.

Yoghurts containing probiotics reduce disruption of the small intestinal barrier in methotrexate-treated rats

Small intestinal permeability was employed to assess the efficacy of commercially available yoghurts containing probiotics in a rat model of methotrexate (MTX)-induced mucositis. Male Sprague-Dawley rats were allocated to four groups (n = 8): MTX + water, MTX + cow's milk yoghurt (CY; fermented with Lactobacillus johnsonii), MTX + sheep's milk yoghurt (SY; containing Lactobacillus bulgaricus and Streptococcus thermophilus), and saline. Treatment gavage occurred twice daily for 7 days pre-MTX and 5 days post-MTX. Intestinal permeability was assessed on days -7, -1, 2, and 5 of the trial. Intestinal sections were collected at sacrifice for histological and biochemical analyses. Histology revealed that rats receiving CY and SY did not have a significantly damaged duodenum compared to controls. However, an improved small intestinal barrier function was evident, determined by a decreased lactulose/mannitol ratio. Probiotics containing SY and CY may be useful in preventing disruption to intestinal barrier function in MTX-induced mucositis.

A comparison of methods used in the UK and Ireland for the extraction and detection of semen on swabs and cloth samples

The recent formation of a United Kingdom and Irish working group, the Body Fluids Forum (BFF), highlighted the need to investigate different working practices prior to any inter-laboratory comparison work and identification of best practice. Various dilutions of semen were seeded onto swabs and cloth samples for each BFF member laboratory to test using their standard techniques. The results showed that the detection of acid phosphatase on swabs is best achieved using direct testing rather than on an extract from the swab. Extraction methods for spermatozoa require a balance to be achieved between using a sufficient volume of water to ensure optimal release and minimal volume to ensure a concentrated extract. PSA tests were investigated and found to be more sensitive than Choline. DNA profiles were obtained from samples in which no spermatozoa had been detected during microscopic examination.

Gastric emptying and the organization of antro-duodenal pressures in the critically ill

The motor dysfunctions underlying delayed gastric emptying (GE) in critical illness are poorly defined. Our aim was to characterize the relationship between antro-duodenal (AD) motility and GE in critically ill patients. AD pressures were recorded in 15 mechanically ventilated patients and 10 healthy volunteers for 2 h (i) during fasting, (ii) following an intragastric nutrient bolus with concurrent assessment of GE using the (13)C-octanoate breath test and (iii) during duodenal nutrient infusion. Propagated waves were characterized by length and direction of migration. Critical illness was associated with: (i) slower GE (GEC: 3.47 +/- 0.1 vs 2.99 +/- 0.2; P = 0.046), (ii) fewer antegrade (duodenal: 44%vs 83%, AD: 16%vs 83%; P < 0.001) and more retrograde (duodenal: 46%vs 12%, AD: 38%vs 4%; P < 0.001) waves, (iii) shorter wave propagation (duodenal: 4.7 +/- 0.3 vs 6.0 +/- 0.4 cm; AD: 7.7 +/- 0.6 vs 10.9 +/- 0.9 cm; P = 0.004) and (iv) a close correlation between GE with the percentage of propagated phase 3 waves that were antegrade (r = 0.914, P = 0.03) and retrograde (r = -0.95, P = 0.014). In critical illness, the organization of AD pressure waves is abnormal and associated with slow GE.

Evaluation of entomopathogenic fungus Metarhizium anisopliae against soil-dwelling stages of cabbage maggot (Diptera: Anthomyiidae) in glasshouse and field experiments and effect of fungicides on fungal activity

The effect of two isolates of the entomopathogenic fungus Metarhizium anisopliae (Metchnikoff) Sorokin (389.93 and 392.93) on root-feeding stages of cabbage root fly, Delia radicum (L.), was studied under glasshouse and field conditions. In glasshouse studies, the effect of drenching a suspension of conidia (concentration 1 x 10(8) m(-1), 40 ml per plant, applied on four occasions) onto the base of cabbage plants infested with D. radicum eggs was compared with mixing conidial suspension into compost modules (concentration 1 x 10(8) ml(-1), 25 ml per plant) used to raise seedlings. Drench application reduced the mean number of larvae and pupae recovered per plant by up to 90%, but the compost module treatment had no statistically significant effect. Both application methods reduced the emergence of adult flies from pupae by up to 92%. Most conidia applied as a drench application remained in the top 10-cm layer of compost. Applications of the fungicides iprodione and tebuconazole, which are used routinely on brassica crops, were compatible with using M. anisopliae 389.93 against D. radicum under glasshouse conditions, even though these fungicides were inhibitory to fungal growth on SDA medium. In a field experiment, drench applications of M. anisopliae 389.93 to the base of cauliflower plants at concentrations of 1 x 10(6) to 1 x 10(8) conidia ml(-1) did not control D. radicum populations, although up to 30% of larval cadavers recovered supported sporulating mycelium. Drench applications often exhibited considerable lateral movement on the soil surface before penetrating the ground, which may have reduced the amount of inoculum in contact with D. radicum larvae.

Laboratory evaluation of entomopathogenic fungi against larvae and adults of onion maggot (Diptera: Anthomyiidae)

Laboratory experiments were done to measure the susceptibility of larvae and adults of the onion maggot, Delia antiqua (Meigen) (Diptera: Muscidae: Anthomyiidae) to 27 isolates of entomopathogenic fungi from four genera [Beauveria Vuillemin, Lecanicillium (Petch) Zare & W. Gams, Metarhizium Sorokin, and Paecilomyces Bainier]. A novel bioassay was developed for D. antiqua larvae by using a diet based on mixed vegetable powder. When evaluated in a virulence screen, the fungal isolates caused less mortality of D. antiqua larvae than adults. Only three isolates caused > 50% mortality of larvae, whereas 12 isolates caused > 50% mortality of adults. Fungal species was a statistically significant factor affecting the mortality of larvae but not of adults. The fungal isolates causing the most mortality of larvae tended to belong to Metarhizium anisopliae (Metschnikoff) Sorokin. Two M. anisopliae isolates (389.93 and 392.93) were evaluated in dose-response bioassays. The median lethal concentrations of the isolates against larvae were 6.1 x 10(7) conidia ml(-1) for isolate 389.93 and 7.6 x 10(7) conidia ml(-1) for isolate 392.93. The emergence of adult flies from pupae was reduced at high concentrations of conidia (3.0 x 10(8) and 1.0 x 10(8) conidia ml(-1)). The median lethal concentrations of the isolates against adults were 1.7 x 10(7) and 4.0 x 10(7) conidia ml(-1), respectively. Some of the fungal isolates examined may have potential as biological control agents of larvae of D. antiqua and related species.

Antro-pyloro-duodenal motor responses to gastric and duodenal nutrient in critically ill patients

BACKGROUND

Gastric emptying is frequently delayed in critical illness which compromises the success of nasogastric nutrition. The underlying motor dysfunctions are poorly defined.

AIMS

To characterise antro-pyloro-duodenal motility during fasting, and in response to gastric and duodenal nutrient, as well as to evaluate the relationship between gastric emptying and motility, in the critically ill.

SUBJECTS

Fifteen mechanically ventilated patients from a mixed intensive care unit; 10 healthy volunteers.

METHODS

Antro-pyloro-duodenal pressures were recorded during fasting, after intragastric administration (100 ml; 100 kcal), and during small intestinal infusion of liquid nutrient (6 hours; 1 kcal/min). Gastric emptying was measured using a (13)C octanoate breath test.

RESULTS

In healthy subjects, neither gastric nor small intestinal nutrient affected antro-pyloro-duodenal pressures. In patients, duodenal nutrient infusion reduced antral activity compared with both fasting and healthy subjects (0.03 (0-2.47) waves/min v 0.14 (0-2.2) fasting (p = 0.016); and v 0.33 (0-2.57)/min in healthy subjects (p = 0.005)). Basal pyloric pressure and the frequency of phasic pyloric pressure waves were increased in patients during duodenal nutrient infusion (3.12 (1.06) mm Hg; 0.98 (0.13)/min) compared with healthy subjects (-0.44 (1.25) mm Hg; p<0.02 after 120 minutes; 0.29 (0.15)/min; p = 0.0002) and with fasting (-0.06 (1.05) mm Hg; p<0.03 after 160 minutes; 0.49 (0.13)/min; (p = 0.0001). Gastric emptying was delayed in patients (gastric emptying coefficient 2.99 (0.2) v 3.47 (0.1); p = 0.015) and inversely related to the number of pyloric pressure waves (r = -0.563, p = 0.029).

CONCLUSIONS

Stimulation of pyloric and suppression of antral pressures by duodenal nutrient are enhanced in the critically ill and related to decreased gastric emptying.

Multipoint measurement of intragastric pH in healthy preterm infants

BACKGROUND

The diagnostic use of 24 hour oesophageal pH monitoring in infants is controversial because of the impact of feed buffering of gastric acidity.

AIM

To re-evaluate the effect of feeding on gastric pH and reflux using multipoint pH measurements.

SUBJECTS

Fifteen healthy premature infants fed every four hours.

METHODS

Oesophageal pH and intragastric pH at 3, 6, and 9 cm below the lower oesophageal sphincter were simultaneously measured using a four channel pH probe for four hours after bolus feeding. Parameters of pH were compared for the different levels within the stomach. During reflux episodes, the nadir pH was compared with intragastric pH at all levels.

RESULTS

The proximal stomach was more significantly buffered by feeding and slower to re-acidify postprandially than the mid and distal stomach (42.2% of the time at pH < 4 compared with 58.7% and 55.7% respectively). During 27 of 62 gastro-oesophageal reflux episodes, nadir oesophageal pH was lower than the pH of the proximal stomach but always equal to or higher than the pH of the distal stomach.

CONCLUSIONS

These data indicate that previous studies may have overestimated the effect of feeding on gastric acidity and reflux.

Pathophysiological mechanisms of gastroesophageal reflux disease in children

Gastroesophageal reflux (GER) is an extremely common pediatric problem, but only in the past few years have we developed a better understanding of its pathophysiology. This is related to the wider use of investigative tools such as flexible endoscopy, 24-hour pH monitoring, and more recently, micromanometric methods and noninvasive breath tests, which have been particularly useful in infants. This paper reviews our current understanding of the esophageal and gastric mechanisms contributing to the pathophysiology of GER. In this context, we also highlight areas where new therapeutic approaches may be beneficial.