Scrotal Lipoblastoma with Radiological and Histological Correlation

Lipoblastomas are rare benign mesenchymal tumors comprised primarily mature adipocytes, which are most commonly found in infants and children younger than 3 years. They are usually found in the extremities, trunk, head, neck, and retroperitoneum, although cases occurring in the scrotum have been reported. Due to its rarity, there is a relative paucity of literature describing its imaging and management. We present a rare case of a scrotal lipoblastoma, and discuss the current imaging strategies to differentiate this adipocytic tumor from other more common paratesticular masses, including aggressive neoplasms such as rhabdomyosarcomas. Knowledge of the radiological appearance of lipoblastoma can provide the correct diagnosis and prevent unnecessary orchiectomy.

Neonatal infratentorial subdural hematoma contributing to obstructive hydrocephalus in the setting of therapeutic cooling: A case report

BACKGROUND

Symptomatic neonatal subdural hematomas usually result from head trauma incurred during vaginal delivery, most commonly during instrument assistance. Symptomatic subdural hematomas are rare in C-section deliveries that were not preceded by assisted delivery techniques. Although the literature is inconclusive, another possible cause of subdural hematomas is therapeutic hypothermia.

CASE SUMMARY

We present a case of a term neonate who underwent therapeutic whole-body cooling for hypoxic ischemic encephalopathy following an emergent C-section delivery for prolonged decelerations. Head ultrasound on day of life 3 demonstrated a rounded mass in the posterior fossa. A follow-up brain magnetic resonance imaging confirmed hypoxic ischemic encephalopathy and clarified the subdural hematomas in the posterior fossa causing mass effect and obstructive hydrocephalus.

CONCLUSION

The aim of this report is to highlight the rarity and importance of mass-like subdural hematomas causing obstructive hydrocephalus, particularly in the setting of hypoxic ischemic encephalopathy and therapeutic whole-body cooling.

Neuroimaging for the Primary Care Provider: A Review of Modalities, Indications, and Pitfalls

When evaluating a child with a potential neurologic or neurodevelopmental disorder, identifying indications for imaging and the correct imaging modality to order can be challenging. This article provides an overview of computed tomography, MRI, ultrasonography, and radiography with an emphasis on indications for use, pitfalls to be avoided, and recent advances. A discussion of the appropriate use of ionizing radiation, intravenous contrast, and sedation is also provided.

Perspective: child abuse in the military

Child maltreatment is an unfortunate aspect of our society, afflicting civilian and military families alike. However, unlike their civilian counterparts, military families bear additional burdens inherent to military service that can exacerbate some of the root causes of child abuse. For this reason, the U.S. Department of Defense is committed to ensuring not only a highly disciplined and ready force, but also a healthy force - the foundation of which is healthy families. Therefore, understanding the military health care system, how it functions and how it collects data is a necessary first step in evaluating the efficacy of current programs and identifying opportunities for improvement. Moving beyond treatment and prevention, the military also boasts an independent judicial system designed to promote the dual interests of justice and good order as well as discipline in the armed forces, and this also contributes to a distinct culture. These two independent systems, often viewed as having diametrically opposed interests, can work together synergistically to promote the ultimate goal of fewer instances of child maltreatment in the military.

Fibromatosis colli leading to positional plagiocephaly with gross anatomical and sonographic correlation

Fibromatosis colli, also known as 'sternocleidomastoid tumour of infancy' or 'pseudotumour of infancy', is a rare condition involving fibrosis and swelling, or 'tumour' of the sternocleidomastoid muscle in newborns that typically occurs after a traumatic delivery. Although usually self-limited, fibromatosis colli can lead to congenital muscular torticollis and positional plagiocephaly due to uneven forces on the neonatal skull. Ultrasound is the diagnostic imaging modality of choice and can prevent additional imaging and unnecessary intervention.

Complex Pancreaticobiliary Maljunction with Pancreas Divisum and Obstructive Pseudocyst

Pancreaticobiliary maljunction (PBM) is the congenital junction of the bile and pancreatic ducts into a common channel located anatomically outside of the duodenal wall. The complex type (Type D) is the rarest type and occurs in conjunction with other pancreaticobiliary anomalies. We present a case of complex PBM with pancreas divisum presenting as acute pancreatitis and obstructive symptoms secondary to a pancreatic pseudocyst. Surgical management is discussed, as complex type PBM is most predisposed to post-operative complications.

Ipsilateral Medial and Lateral Discoid Menisci: A Rare Combination of Infrequent Anatomic Variants

A discoid meniscus is a thick, disk-shaped meniscus which is prone to tearing, degeneration, and loss of stability in the knee. A discoid meniscus most commonly affects the lateral meniscus, rarely the medial meniscus. Here, we present a case of an extremely rare medial and lateral discoid meniscus in the ipsilateral knee of a 10-year-old male. Ipsilateral medial and discoid menisci are incredibly rare and one must keep this entity in mind to avoid confusion while interpreting knee magnetic resonance imaging.

Rare case of atypical Dejerine syndrome in a child

Medial medullary syndrome (aka Dejerine syndrome) is a rare condition that develops following infarction of the medial medulla and is classically defined by the presence of Dejerine’s triad of contralateral weakness in upper and lower extremities, contralateral hemisensory loss of vibration and proprioception, and ipsilateral tongue weakness. It is typically caused by occlusion of the vertebral artery or one of its branches. We report the case of a 6-year-old girl who suffered a medial medullary infarction, and she was diagnosed with atypical Dejerine syndrome. Medial medullary infarct leading to atypical Dejerine syndrome has not been reported in this young of a patient in the literature to date.

Nonvisualization of the ovaries on pelvic ultrasound: does MRI add anything?

PURPOSE

The purpose of our study is to assess the utility of pelvic magnetic resonance imaging (MRI) in the event that either one or both ovaries are not visualized by pelvic ultrasound.

MATERIALS AND METHODS

This HIPAA-compliant retrospective study was approved by our local institutional review board and informed consent waived. 1926 pelvic MRI examinations between March 2007 and December 2011 were reviewed and included if a combined transabdominal and endovaginal pelvic ultrasound had been performed in the preceding 6 months with at least one ovary nonvisualized. Ovaries not visualized on pelvic ultrasound were assumed to be normal and compared with the pelvic MRI findings. MRI findings were categorized as concordant or discordant. Discordant findings were divided into malignant, non-malignant physiologic or non-malignant non-physiologic. The modified Wald, the "rule of thirds", and the binomial distribution probability tests were performed.

RESULTS

255 pelvic ultrasounds met inclusion criteria with 364 ovaries not visualized. 0 malignancies were detected on MRI. 6.9% (25/364) of nonvisualized ovaries had non-malignant discordant findings on MRI: 5.2% (19/364) physiologic, 1.6% (6/364) non-physiologic. Physiologic findings included: 16 functional cysts and 3 hemorrhagic cysts. Non-physiologic findings included: 3 cysts in post-menopausal women, 1 hydrosalpinx, and 2 broad ligament fibroids. The theoretical risk of detecting an ovarian carcinoma on pelvic MRI when an ovary is not visualized on ultrasound ranges from 0 to 1.3%.

CONCLUSION

If an ovary is not visualized on pelvic ultrasound, it can be assumed to be without carcinoma and MRI rarely adds additional information.

Genome-wide prediction of age at puberty and reproductive longevity in sows

Traditional selection for sow reproductive longevity is ineffective due to low heritability and late expression of the trait. Incorporation of DNA markers into selection programs is potentially a more practical approach for improving sow lifetime productivity. Using a resource population of crossbred gilts, we explored pleiotropic sources of variation that influence age at puberty and reproductive longevity. Of the traits recorded before breeding, only age at puberty significantly affected the probability that females would produce a first parity litter. The genetic variance explained by 1-Mb windows of the sow genome, compared across traits, uncovered regions that influence both age at puberty and lifetime number of parities. Allelic variants of SNPs located on SSC5 (27-28 Mb), SSC8 (36-37 Mb) and SSC12 (1.2-2 Mb) exhibited additive effects and were associated with both early expression of puberty and a greater than average number of lifetime parities. Combined analysis of these SNPs showed that an increase in the number of favorable alleles had positive impact on reproductive longevity, increasing number of parities by up to 1.36. The region located on SSC5 harbors non-synonymous alleles in the arginine vasopressin receptor 1A (AVPR1A) gene, a G-protein-coupled receptor associated with social and reproductive behaviors in voles and humans and a candidate for the observed effects. This region is characterized by high levels of linkage disequilibrium in different lines and could be exploited in marker-assisted selection programs across populations to increase sow reproductive longevity.

Changes in brain network activity during working memory tasks: a magnetoencephalography study

In this study, we elucidate the changes in neural oscillatory processes that are induced by simple working memory tasks. A group of eight subjects took part in modified versions of the N-back and Sternberg working memory paradigms. Magnetoencephalography (MEG) data were recorded, and subsequently processed using beamformer based source imaging methodology. Our study shows statistically significant increases in θ oscillations during both N-back and Sternberg tasks. These oscillations were shown to originate in the medial frontal cortex, and further to scale with memory load. We have also shown that increases in θ oscillations are accompanied by decreases in β and γ band oscillations at the same spatial coordinate. These decreases were most prominent in the 20-40 Hz frequency range, although spectral analysis showed that γ band power decrease extends up to at least 80 Hz. β/γ Power decrease also scales with memory load. Whilst θ increases were predominately observed in the medial frontal cortex, β/γ decreases were associated with other brain areas, including nodes of the default mode network (for the N-back task) and areas associated with language processing (for the Sternberg task). These observations are in agreement with intracranial EEG and fMRI studies. Finally, we have shown an intimate relationship between changes in β/γ band oscillatory power at spatially separate network nodes, implying that activity in these nodes is not reflective of uni-modal task driven changes in spatially separate brain regions, but rather represents correlated network activity. The utility of MEG as a non-invasive means to measure neural oscillatory modulation has been demonstrated and future studies employing this technology have the potential to gain a better understanding of neural oscillatory processes, their relationship to functional and effective connectivity, and their correspondence to BOLD fMRI.

Occurrence of microalbuminuria in young people with Type 1 diabetes: importance of age and diabetes duration

AIMS

To determine the occurrence of microalbuminuria in young people with Type 1 diabetes mellitus followed prospectively for 2 years and to relate the presence of persistent elevations in urinary albumin excretion (UAE) to age, diabetes duration, puberty and other factors.

METHODS

During a 2 year period, random urine samples were obtained from 471 patients, aged 8-18 years (mean +/-sd 12.9 +/- 2.3 years) with Type 1 diabetes duration 5.6 +/- 3.0 years, as part of routine clinical care. Urine albumin and creatinine concentrations were measured in 1310 samples (median, 3 samples per patient) and the albumin:creatinine ratio was calculated (in micrograms albumin per milligram creatinine). Height, weight, blood pressure (BP), glycated haemoglobin (HbA(1c)), blood glucose monitoring frequency and Tanner staging were collected from patients' medical records.

RESULTS

Twenty-three per cent of patients had one or more sample with elevated UAE (> or =20 microg/mg) and 9.3% had persistent elevations (> or =2 samples > or =20 microg/mg). Those with and without persistent microalbuminuria did not differ significantly in age, diabetes duration, z-score for body mass index, pubertal status or BP percentile. Ten per cent of children <13 years old and 9% of children > or =13 years old had persistent microalbuminuria. Persistent microalbuminuria was significantly associated with diabetes duration only in older children (duration 0.5-3 years, 4%; 4-6 years, 8%; > or =7 years, 14%; P = 0.02, trend test). Mean HbA(1c) over the 2 years was 8.7 +/- 1.2%. In a logistic regression model, mean HbA(1c) was the only significant predictor of persistent microalbuminuria (odds ratio 1.3, 95% confidence interval 1.0-1.6, P = 0.05).

CONCLUSIONS

Microalbuminuria in older children with Type 1 diabetes is likely to be clinically significant. In younger children, it may reflect functional, reversible renal changes. Longitudinal analysis is needed to confirm the probable transient nature of microalbuminuria in young patients with Type 1 diabetes.

Fine mapping of genetic susceptibility to polycystic ovary syndrome on chromosome 19p13.2 and tests for regulatory activity

CONTEXT

Little is known about genes that contribute to polycystic ovary syndrome (PCOS). We previously found linkage and association of PCOS with the dinucleotide marker D19S884 in two independent sets of families; allele 8 of D19S884 confers increased risk.

OBJECTIVE/DESIGN

The objectives of the study were: 1) use the transmission/disequilibrium test (TDT) to assess linkage and association between PCOS and D19S884 (and nearby markers) in a third set of families; and 2) test D19S884 and surrounding DNA sequence for in vitro regulatory activity in lymphoblastoid cell lines (LCLs) and granulosa cells.

SETTING/SUBJECTS

We studied 98 new families with a PCOS proband, father, mother, and other available offspring. We analyzed data from these families separately and in combination with data obtained previously.

INTERVENTIONS

Interventions were venipuncture.

MAIN OUTCOME MEASURES

Measures were transmission frequencies and in vitro functional studies.

RESULTS

The first result we found was that in the 98 new families, the TDT was significant for allele 8 of D19S884 (P = 0.043). In the total collection of 465 families, the TDT evidence is very strong (nominal P < 7 x 10(-5)). Results for all other genetic markers near D19S884 were nonsignificant after correction for multiple testing. The second result was that an approximately 800-bp fragment containing various alleles of D19S884 showed modest but reproducible promoter activity in LCLs. However, no allelic differences were detected. No activity of this fragment was detected in granulosa cells.

CONCLUSIONS

This is the second independent confirmation of linkage and association of D19S884 with PCOS. We found in addition that some sequence in the region of D19S884 confers in vitro promoter activity in LCLs.

Soil carbon dioxide partial pressure and dissolved inorganic carbonate chemistry under elevated carbon dioxide and ozone

Global emissions of atmospheric CO(2) and tropospheric O(3) are rising and expected to impact large areas of the Earth's forests. While CO(2) stimulates net primary production, O(3) reduces photosynthesis, altering plant C allocation and reducing ecosystem C storage. The effects of multiple air pollutants can alter belowground C allocation, leading to changes in the partial pressure of CO(2) (pCO(2)) in the soil , chemistry of dissolved inorganic carbonate (DIC) and the rate of mineral weathering. As this system represents a linkage between the long- and short-term C cycles and sequestration of atmospheric CO(2), changes in atmospheric chemistry that affect net primary production may alter the fate of C in these ecosystems. To date, little is known about the combined effects of elevated CO(2) and O(3) on the inorganic C cycle in forest systems. Free air CO(2) and O(3) enrichment (FACE) technology was used at the Aspen FACE project in Rhinelander, Wisconsin to understand how elevated atmospheric CO(2) and O(3) interact to alter pCO(2) and DIC concentrations in the soil. Ambient and elevated CO(2) levels were 360+/-16 and 542+/-81 microl l(-1), respectively; ambient and elevated O(3) levels were 33+/-14 and 49+/-24 nl l(-1), respectively. Measured concentrations of soil CO(2) and calculated concentrations of DIC increased over the growing season by 14 and 22%, respectively, under elevated atmospheric CO(2) and were unaffected by elevated tropospheric O(3). The increased concentration of DIC altered inorganic carbonate chemistry by increasing system total alkalinity by 210%, likely due to enhanced chemical weathering. The study also demonstrated the close coupling between the seasonal delta(13)C of soil pCO(2) and DIC, as a mixing model showed that new atmospheric CO(2) accounted for approximately 90% of the C leaving the system as DIC. This study illustrates the potential of using stable isotopic techniques and FACE technology to examine long- and short-term ecosystem C sequestration.

The biochemical basis for increased testosterone production in theca cells propagated from patients with polycystic ovary syndrome

Ovarian theca cells propagated from patients with polycystic ovary syndrome (PCOS) convert steroid precursors into T more efficiently than normal theca cells. To identify the basis for increased T production by PCOS theca cells, we examined type I-V 17 beta-hydroxysteroid dehydrogenase (17 beta HSD) isoform expression in long-term cultures of theca and granulosa cells isolated from normal and PCOS ovaries. RT-PCR analysis demonstrated that theca cells express type V 17 beta HSD a member of the aldo-keto reductase (AKR) superfamily (17 beta HSDV, AKR1C3), whereas expression of type I, II, and IV 17 beta HSD, which are members of the short-chain dehydrogenase/reductase superfamily, was limited to granulosa cells. Type III 17 beta HSD, the testicular isoform, was not detected in either granulosa or theca cells. Northern and real-time PCR analyses demonstrated that 17 beta HSDV transcripts were not significantly increased in PCOS theca cells compared with normal theca cells. RT-PCR analysis revealed that theca cells also express another AKR, 20 alpha HSD (AKR1C1). Both basal and forskolin-stimulated 20 alpha HSD mRNA levels were increased in PCOS theca cells compared with normal theca cells. However, 17 beta HSD enzyme activity per theca cell was not significantly increased in PCOS, suggesting that neither AKR1C3 nor AKR1C1 contributes to the formation of T in this condition. In contrast, 17 alpha-hydroxylase/C17,20 lyase and 3 beta HSD enzyme activities were elevated in PCOS theca cells, driving increased production of T precursors. These findings indicate that 1) increased T production in PCOS theca cells does not result from dysregulation of "androgenic" 17 beta HSD activity or altered expression of AKRs that may express 17 beta HSD activity; and 2) increased synthesis of T precursors is the primary factor driving enhanced T secretion in PCOS.

Interaction of estrogen receptors alpha and beta with estrogen response elements

To understand how estrogen-responsive genes are regulated, we compared the abilities of estrogen receptors (ERs) alpha and beta to bind to and activate transcription through the consensus vitellogenin A2 ERE and the imperfect pS2, vitellogenin B1, and oxytocin (OT) EREs. Transient transfection experiments demonstrated that ERalpha and ERbeta induced the highest levels of transcription with the A2 ERE, intermediate levels of transcription with the OT ERE, and low levels of transcription with the pS2 and B1 EREs. ERalpha and ERbeta had higher affinities for the A2 ERE than for any of the three imperfect EREs but similar affinities for the pS2, B1, and OT EREs in gel mobility shift assays. ERalpha had a higher affinity and was a more potent activator of transcription than ERbeta. Interestingly, protease sensitivity assays demonstrated that A2, pS2, B1, and OT EREs induced distinct changes in ERalpha and ERbeta conformation thereby providing different functional surfaces for interaction with regulatory proteins involved in control of estrogen-responsive genes.

Allosteric modulation of estrogen receptor conformation by different estrogen response elements

Estrogen-regulated gene expression is dependent on interaction of the estrogen receptor (ER) with the estrogen response element (ERE). We assessed the ability of the ER to activate transcription of reporter plasmids containing either the consensus vitellogenin A2 ERE or the imperfect pS2, vitellogenin B1, or oxytocin (OT) ERE. The A2 ERE was the most potent activator of transcription. The OT ERE was significantly more effective in activating transcription than either the pS2 or B1 ERE. In deoxyribonuclease I (DNase I) footprinting experiments, MCF-7 proteins protected A2 and OT EREs more effectively than the pS2 and B1 EREs. Limited protease digestion of the A2, pS2, B1, or OT ERE-bound receptor with V8 protease or proteinase K produced distinct cleavage products demonstrating that individual ERE sequences induce specific changes in ER conformation. Receptor interaction domains of glucocorticoid receptor interacting protein 1 and steroid receptor coactivator 1 bound effectively to the A2, pS2, B1, and OT ERE-bound receptor and significantly stabilized the receptor-DNA interaction. Similar levels of the full-length p160 protein amplified in breast cancer 1 were recruited from HeLa nuclear extracts by the A2, pS2, B1, and OT ERE-bound receptors. In contrast, significantly less transcriptional intermediary factor 2 was recruited by the B1 ERE-bound receptor than by the A2 ERE-bound receptor. These studies suggest that allosteric modulation of ER conformation by individual ERE sequences influences the recruitment of specific coactivator proteins and leads to differential expression of genes containing divergent ERE sequences.

Clinical outcomes after aortic valve replacement with the Toronto stentless porcine valve

BACKGROUND

Hemodynamic benefits of the Toronto stentless porcine valve have been documented. Clinical well-being and freedom from major valve-related events have been less well defined.

METHODS

A total of 447 patients were prospectively followed for up to 8 years (1,745.2 valve years total, 3.9 valve years/patient). The patient demographics included 66% men, mean age 65 years, New York Heart Association functional class III-IV 55%, concomitant coronary artery bypass grafting 41%.

RESULTS

We found that 83.7% of patients were in New York Heart Association functional class I and 80.8% had 0 to 1+ aortic insufficiency. Mean gradient at 6 years (n = 75) was 4.4 mm Hg and mean effective orifice area (EOA) 2.4 cm2. Late adverse event rates per patient per year were: embolism 1.0%, endocarditis 0.4%, thrombosis 0%, structural deterioration 0.2%, explant 0.3%, and valve-related death 0.6%. Freedom from valve-related death at 6 years was 95.8%; from cardiac death 96.3%. Freedom from endocarditis was 98.4%, from embolism 93.9%, from structural deterioration 97.4%, and freedom from explant 98.1%. For patients older than 60 years, freedom from structural deterioration was 100%.

CONCLUSIONS

These results confirm satisfactory clinical outcomes after aortic valve replacement with the Toronto stentless porcine valve, with a low incidence of valve-related adverse events as long as 96 months after valve replacement.

Trial of labour after four Caesarean sections: a case report and literature review

We present the case of a woman who requested trial of labour following four Caesarean sections and achieved a vaginal birth. We discuss the recent legal rulings pertaining to patient consent in respect to Caesarean section and published data on outcomes following trial of labour after more than 1 Caesarean section.

Regulation of the estrogen-responsive pS2 gene in MCF-7 human breast cancer cells

To understand how hormones and antihormones regulate transcription of estrogen-responsive genes, in vivo footprinting was used to examine the endogenous pS2 gene in MCF-7 cells. While the consensus pS2 estrogen response element (ERE) half site was protected in the absence of hormone, both the consensus and imperfect ERE half sites were protected in the presence of estrogen. 4-Hydroxytamoxifen and ICI 182,780 elicited distinct footprinting patterns, which differed from those observed with vehicle- or with estrogen-treated cells suggesting that the partial agonist/antagonist and antagonist properties of 4-hydroxytamoxifen or ICI 182,780, respectively, may be partially explained by modulation of protein-DNA interactions. Footprinting patterns in and around the TATA and CAAT sequences were identical in the presence and in the absence of estrogen suggesting that the basal promoter is accessible and poised for transcription even in the absence of hormone. In vitro DNase I footprinting experiments demonstrated that the estrogen receptor bound to the pS2 ERE and that adjacent nucleotides were protected by MCF-7 nuclear proteins. These findings indicate that transcription of the pS2 gene is modulated by alterations in protein binding to multiple sites upstream of the basal promoter, but not by changes in protein-DNA interactions in the basal promoter.

Review article: one-week clarithromycin triple therapy regimens for eradication of Helicobacter pylori

BACKGROUND

One-week triple therapies have been endorsed as the treatment regimens of choice for eradication of Helicobacter pylori infection. Those that include clarithromycin appear to be the most effective.

AIM

To review reports of triple therapies that include clarithromycin.

METHODS

Reports were identified from the literature to May 1998. The variation between study designs prevents a formal meta-analysis. A measure of the relative efficacies of regimens has, however, been gained by comparison and by pooling of intention-to-treat eradication rates.

RESULTS

One hundred and ninety-two studies were identified which included 264 treatment arms of a 1-week triple therapy composed of clarithromycin with amoxycillin or a nitroimidazole (metronidazole or tinidazole), and either ranitidine bismuth citrate or a proton pump inhibitor (omeprazole, lansoprazole or pantoprazole). From reports of these studies, an intention-to-treat H. pylori eradication rate could be determined from 210 treatment arms of 151 studies.

CONCLUSIONS

There is little to choose between the efficacies of 1-week clarithromycin-based triple therapy eradication regimens. However, those comprising clarithromycin, a nitroimidazole and either ranitidine bismuth citrate or a high dose of omeprazole are, in general, the most effective. Against antibiotic-resistant strains of H. pylori, regimens including ranitidine bismuth citrate may be more effective than those including a proton pump inhibitor.

The high mobility group protein 1 enhances binding of the estrogen receptor DNA binding domain to the estrogen response element

We have examined the ability of the high-mobility group protein 1 (HMG1) to alter binding of the estrogen receptor DNA-binding domain (DBD) to the estrogen response element (ERE). HMG1 dramatically enhanced binding of purified, bacterially expressed DBD to the consensus vitellogenin A2 ERE in a dose-dependent manner. The ability of HMG1 to stabilize the DBD-ERE complex resulted in part from a decrease in the dissociation rate of the DBD from the ERE. Antibody supershift experiments demonstrated that HMG1 was also capable of forming a ternary complex with the ERE-bound DBD in the presence of HMG1-specific antibody. HMG1 did not substantially affect DBD-ERE contacts as assessed by methylation interference assays, nor did it alter the ability of the DBD to induce distortion in ERE-containing DNA fragments. Because HMG1 dramatically enhanced estrogen receptor DBD binding to the ERE, and the DBD is the most highly conserved region among the nuclear receptor superfamily members, HMG1 may function to enhance binding of other nuclear receptors to their respective response elements and act in concert with coactivator proteins to regulate expression of hormone-responsive genes.

Estrogen response elements function as allosteric modulators of estrogen receptor conformation

The estrogen receptor (ER) is a ligand-dependent transcription factor that regulates the expression of estrogen-responsive genes. ER-mediated transcriptional changes are brought about by interaction of the ER with the estrogen response element (ERE). In this study, we examined the interaction of the Xenopus laevis ER DNA binding domain (DBD) and the intact ER with the X. laevis vitellogenin A2 ERE and the human pS2 ERE. Using gel mobility shift, DNase I footprinting, and methylation interference assays, we demonstrated that the DBD bound only as a dimer to the A2 ERE. However, the DBD bound as a monomer to the consensus pS2 ERE half site at lower DBD concentrations and then as a homodimer to the consensus and imperfect pS2 ERE half site at higher DBD concentrations. Antibody supershift experiments carried out with partially purified, yeast-expressed full-length ER demonstrated that three ER-specific antibodies interacted differentially with A2 and pS2 ERE-bound ER, indicating that receptor epitopes were differentially exposed. Furthermore, partial digestion of the A2 and pS2 ERE-bound ER with chymotrypsin or trypsin produced distinct protease cleavage patterns. Taken together, these data provide evidence that differential interaction of the DBD with the A2 and pS2 EREs brings about global changes in ER conformation. The conformational changes in ER induced by individual ERE sequences could lead to association of the receptor with different transcription factors and assist in the differential modulation of estrogen-responsive genes in target cells.

New options in Helicobacter pylori eradication: efficacy, resistance and synergy

The eradication of Helicobacter pylori has become the focus of much attention since the first attempts at developing effective therapies some 10 years ago. This review focuses on ranitidine bismuth citrate (RBC), the first new drug to be introduced for use in the eradication of H. pylori. RBC when combined with clarithromycin gives consistently high eradication rates (above 80% intention-to-treat assessment in double-blind, international studies) as a simple dual therapy for 14 days or when combined with two antibiotics as a triple therapy for 7 days. RBC enhances the in vitro killing of H. pylori by antibiotics, such as clarithromycin, metronidazole or tetracycline, in a synergistic manner. This effect is seen even when the H. pylori strains are 'resistant' to the antibiotics. Such a synergistic effect probably explains the increased efficacy of RBC-clarithromycin dual therapies compared with clarithromycin dosed with acid-suppressive agents such as H2-receptor antagonists or proton-pump inhibitors.

Colorectal epithelial cell proliferative kinetics and risk factors for colon cancer in sporadic adenoma patients

Colorectal epithelial cell proliferative kinetics are altered in patients at increased risk for colon cancer: proliferation rates [labeling index (LI)] are higher and there is a shift of the proliferative zone from one confined to the lower 60% of the colonic crypt to one that includes the entire crypt (higher phi(h)). To assess factors associated with LI and phi(h), we performed a cross-sectional analysis using baseline rectal mucosal biopsies from sporadic adenoma patients participating in a chemoprevention trial. Biopsies (taken without preparatory cleansing) were taken 10 cm above the level of the anus, and proliferation was assessed by detection of endogenous S-phase-associated proliferating cell nuclear antigen by immunohistochemical methods. High-quality, scorable biopsies were obtained for 115 patients, and using analysis of covariance and multiple linear regression, the LI and phi(h) were evaluated in relation to diet and other lifestyle factors, demographics, anthropometrics, family history of colon cancer, and polyp history. Statistically significant findings included the following: (a) The LI for those in the upper versus the lowest tertile of vegetable and fruit consumption was, proportionately, 35% lower (3.4% versus 5.3%; P < 0.001); for vitamin supplement users versus nonusers, it was 36% lower (3.3 versus 5.2%; P < 0.001); for recurrent versus incident polyp patients, it was 36% higher (6.2 versus 4.0%; P < 0.001); and for those with rectal polyps only versus those with colon polyps only, it was 28% higher (6.0 versus 4.3%; P = 0.05); and (b) the phi(h) for those in the upper versus the lowest tertile of sucrose consumption was, proportionately, 48% higher (7.1% versus 3.7%; P = 0.01). These results indicate that (a) colorectal epithelial cell proliferation rates are higher in recurrent adenoma patients than in incident adenoma patients and in patients with rectal adenomas only versus those with colon adenomas only, but they are lower in patients with higher intakes of vegetables and fruit and in those who take vitamin/mineral supplements, and (b) the distribution of proliferating cells is shifted toward more inclusion of the upper 40% of the crypt in patients with higher intakes of sucrose. The pattern of positive, negative, and null associations of potential risk factors with cell proliferation is similar to that commonly found with colonic neoplasms.

Calcium and colorectal epithelial cell proliferation in ulcerative colitis

In persons at higher risk for colon cancer (e.g., those with sporadic adenoma or ulcerative colitis), compared to those at lower risk, colonic epithelial cell proliferation kinetics are altered. We have shown previously that calcium supplementation appears to normalize the distribution of proliferating cells without affecting the proliferation rate in the colorectal mucosa of sporadic adenoma patients. In a pilot randomized, double-blind, placebo-controlled, clinical trial conducted concurrently with our previously published sporadic adenoma trial, we tested whether calcium supplementation can also modulate cell proliferation kinetics in patients with ulcerative colitis. Ulcerative colitis patients (n = 31) were randomized to placebo or 2.0 g of supplemental calcium daily. Colorectal epithelial cell proliferation was determined by immunohistochemical detection of proliferating cell nuclear antigen labeling of cells in "nonprep" rectal biopsies taken at randomization and after 2 months treatment. All biopsies were scored by one reviewer. Differences in mean follow-up minus baseline labeling index (LI; the proportion of colon crypt epithelial cells that were labeled) and in the phi(h) (proportion of labeled cells that were in the upper 40% of the crypts) were compared with analysis of covariance. Pill-taking adherence was 97%. Biopsy-scoring reliability was high (r = 0.89). The pooled baseline LI and phi(h) were 6.3% and 5.6%, respectively. The LI in the calcium group decreased by 0.5% (proportionately, 3%) more than in the placebo group (P = 0.91). Similarly, the phi(h) in the calcium group decreased by 0.3% (proportionately, 10%) more than in the placebo group (P = 0.85). This pilot study does not suggest that 2.0 g of calcium as calcium carbonate daily can substantially normalize either the rate or distribution of proliferating cells over a 2-month period in the colon crypts of patients with ulcerative colitis; a more definitive answer to the question of whether calcium may be effective would require a study with a larger sample size and/or other study design modifications.

Clarithromycin dual therapy regimens for eradication of Helicobacter pylori: a review

BACKGROUND

Peptic ulcer disease can be cured by eradication of Helicobacter pylori during treatment to heal the ulcer. Dual therapy regimens were among the first to be granted approval for use. Reports of dual therapies including clarithromycin as the sole antibiotic are reviewed.

METHODS

Reports were identified from literature up to May 1997. Information reviewed included patient population, medical diagnosis, trial design, eradication regimens, and H. pylori eradication rates. The great diversity between studies limits formal meta-analysis but a measure of relative efficacy has been obtained by comparison of eradication rates derived by clearly defined methods and by pooling data.

RESULTS

Seventy-five reports of trials with 104 dual therapy treatment arms were reviewed. H. pylori eradication rates reported with ranitidine bismuth citrate plus clarithromycin range from 70-96% with a pooled observed rate of 85%. With omeprazole plus clarithromycin, reported eradication rates range from 27-90% with the pooled reported rate being 66%. Few data are available with either lansoprazole or ranitidine hydrochloride plus clarithromycin.

CONCLUSION

High H. pylori eradication rates derived by consistent and clearly defined methods have been seen with ranitidine bismuth citrate plus clarithromycin. Lower and more variable rates are reported with clarithromycin and either a proton pump inhibitor or a histamine H2-receptor antagonist.

Equilibrium binding of estrogen receptor with DNA using fluorescence anisotropy

Interaction of estrogen receptor (ER) with DNA sequences known as estrogen response elements (ERE) is required for estrogen regulation of the expression of target genes. To characterize the affinity and specificity of ER interaction with ERE sequences in vitro under equilibrium conditions, fluorescence anisotropy assays were performed using recombinant, purified ER and a fluorescein-labeled 35-base pair oligonucleotide bearing an idealized palindromic ERE. In buffer containing 100 mM KCl, the baculovirus-expressed, purified human ER bound with similar affinity to the consensus ERE and a mutant ERE with a single base pair change per half-site. Above 225 mM KCl, ER exhibited discrimination between the consensus and mutated ERE targets. Between 225 and 275 mM KCl, binding to the consensus ERE was independent of salt concentration and occurred with an equilibrium dissociation constant (Kd) of 1.8 +/- 0.6 nM, whereas binding to the mutant ERE was not detected at ER concentrations below 100 nM under the same conditions. At 300 mM KCl, the Kd for the consensus ERE increased approximately 25-fold, suggesting complex salt concentration dependence. Both estrogen-occupied and unoccupied ER bound to the consensus ERE sequence with similar affinity, indicating that estrogen affects ER activity at a step other than DNA binding. Unlike the full-length ER, the recombinant DNA binding domain of ER did not discriminate between the consensus and mutated ERE sequences even at buffer salt concentrations greater than 200 mM NaCl, suggesting that ER sequences outside the DNA binding domain may be important in promoting specific binding.

Methodological findings and considerations in measuring colorectal epithelial cell proliferation in humans

The methodological issues for measuring colorectal epithelial cell proliferation, an intermediate end point for studies of colon neoplasia, in epidemiological studies are deceptively numerous and complex, with few methodological data available. Accordingly, during our experience with measuring colorectal epithelial cell proliferation from nearly 500 participants attending over 1300 study visits over a 6-year period, we recorded data on a variety of measurement variations. Methods investigated included rectal biopsy technique, general histological and labeling procedures [including the tritiated thymidine, 5-bromodeoxyuridine (BrdUrd), and the proliferating cell nuclear antigen (PCNA) immunohistochemical techniques used to label S-phase cells in colonic crypts in rectal biopsy specimens], biopsy scoring procedures, and summary scoring methods. Findings include that the PCNA technique was the simplest, most economical, and least time-consuming. The BrdUrd labeling failure rate was 15% versus < 1% for PCNA. The percentage of labeled cells (labeling index) was highest using PCNA in biopsies processed without prior incubation, intermediate using PCNA in biopsies processed with prior incubation as for BrdUrd, and lowest using BrdUrd. The percentage of labeled cells that were in the upper 40% of the crypt (phi h) was higher using BrdUrd than PCNA; visit-to-visit correlations were higher using PCNA (r = 0.51 versus 0.35), and visit-to-visit variability was lower and between-person variability was higher using PCNA. Intra- and inter-rater reliabilities for the techniques were comparable (PCNA intra-rater r = 0.93, inter-rater r = 0.92). The PCNA technique, compared to the BrdUrd technique, is more feasible and reliable, provides a more accurate estimate of the labeling index, and cell proliferation measures determined with PCNA have statistical properties that are generally more favorable for detecting differences in clinical trials. Thus, the PCNA technique may be preferable to techniques requiring incubation of biopsies. Other methodological findings lead us to recommend that, for larger studies measuring colorectal epithelial cell proliferation on outpatient rectal biopsies, biopsies should be taken 10 cm above the anus using a flexible, preferably jumbo cup, endoscopic forceps through a rigid sigmoidoscope, and histological sections should be 3 microns thick taken 50 microns apart.

Ranitidine bismuth citrate plus clarithromycin for the eradication of H. pylori

Reported observed intention-to-treat eradication rates for ranitidine bismuth citrate plus clarithromycin for 14 days range from 70-86% in studies from the USA and 82-96% in multinational studies carried out primarily in Europe. Two double-blind head-to-head comparisons with omeprazole plus clarithromycin or amoxycillin have shown that ranitidine bismuth citrate plus clarithromycin gives considerably higher eradication rates than the omeprazole based regimens. Ongoing studies will define the efficacy of shorter duration dual therapies and provide further data on two antibiotics with ranitidine bismuth citrate. The possibility that ranitidine bismuth citrate may help in the eradication of resistant organisms and even in the prevention of primary resistance requires further work to expand the preliminary in vitro observations. In the meantime, it can be concluded that ranitidine bismuth citrate, when used in conjunction with clarithromycin for 14 days, is an effective therapy for the eradication of H. pylori.

The safety of ranitidine in over a decade of use

BACKGROUND

Ranitidine hydrochloride (Zantac) is one of the most extensively studied and widely used drugs of all time. This has provided an excellent opportunity to define its safety profile.

METHODS

Data from 189 controlled clinical trials in which more than 26,000 patients received daily doses of ranitidine for 4 weeks or more were reviewed. More than 80% of patients were treated with up to 300 mg ranitidine daily; the remaining patients received doses of up to 1200 mg daily. Eighty-seven trials were placebo controlled. Analyses of post-marketing surveillance and a database of all spontaneously reported adverse events were also evaluated.

RESULTS

Overall in the clinical trial programme adverse events were reported by 20% of those receiving ranitidine compared with 27% of those receiving placebo. The pattern of events was similar in all treatment groups with no evidence of dose-related toxicity in regimens encompassing an eightfold range of therapeutic doses. Similarly in a programme of studies designed to evaluate a dose of ranitidine of 75 mg for non-prescription (over-the-counter) use in the treatment of heartburn, ranitidine was not associated with an adverse event profile distinct from that of placebo. Analysis of spontaneously reported adverse event data allowed identification of rare idiosyncratic events.

CONCLUSIONS

Review of data from a large population of controlled clinical trials with analyses of postmarketing surveillance studies and spontaneously reported adverse events confirmed the excellent safety profile of ranitidine.

Contractile activity of the uterus prior to labor alters the temporal organization of spontaneous motor activity in the fetal sheep

Contractile activity of the uterus before the onset of labor (uterine contractures) has been described in a number of species and provides a powerful source of repeated stimulation for the fetus throughout much of gestation. To understand how fetal behavior responds to this dynamic aspect of the intrauterine environment, we investigated the effects of uterine contractures on the temporal organization of spontaneous motor activity in the fetal sheep during the last fifth of gestation. Eleven fetuses were instrumented on 113-116 days of gestation (dGA). Electromyogram (EMG) activity was recorded from flexor and extensor muscles in the fetal forelimbs and hindlimbs, and from the uterus. Pooled limb EMG activity from 2300 hr to 0700 hr on 118, 125, 132, and 139 dGA before, during, and after uterine contractures was spectral analyzed to detect and quantify the cyclic organization in fetal motor activity. There was strong evidence of cyclic organization in fetal motor activity (CM) at each gestational age, similar to what has been described in the fetal rat and human. There was no evidence of developmental changes in the baseline spectral measures of CM. The most prominent feature of the response of CM to uterine contractures was a transient decrease in irregularity at 118-132 dGA. The strength of CM increased during contractures at 125 and 132 dGA, and a slight acceleration of CM during contractures was detected at 118 and 139 dGA. The results demonstrate that the stimulation associated with contractures influences an important source of complexity in early behavioral organization. The results are consistent with speculation by others that uterine contractures might induce transient cerebral hypoxemia in the fetus, and suggest that conditions established in the first few minutes of sustained uterine activity constitute the effective perturbation of CM.

The Safety of Ranitidine Bismuth Citrate in Controlled Clinical Studies

Ranitidine bismuth citrate (Pylorid, Tritec) is a novel drug which heals peptic ulcers and when co-prescribed with either clarithromycin or amoxycillin eradicatesHelicobacter pylori. In controlled clinical studies it was well-tolerated when given alone or when co-prescribed with either antibiotic. Data from 20 clinical studies are reported in this analysis of safety with almost 5000 patients having received ranitidine bismuth citrate (200, 400, or 800 mg twice daily). The incidence of adverse events reported with this new drug, either alone or with an antibiotic, was not different from or lower than in patients given placebo and was independent of the dose of ranitidine bismuth citrate tested. Most commonly reported events (>1% of patients) were upper respiratory tract infection, constipation, diarrhoea, nausea and vomiting, dizziness, and headache, the latter being the only event reported by >2% of patients who received ranitidine bismuth citrate alone. Adverse events considered by the clinical investigator to be adverse reactions occurred with a similar frequency amongst patients given ranitidine bismuth citrate (8%), ranitidine hydrochloride (6%), or placebo (6%). The incidence of adverse reactions was greater when co-prescribed with amoxycillin (11%) or clarithromycin (20%) although it was not different from that noted with the antibiotics alone. Serious adverse events were reported in similar proportions of patients given placebo, ranitidine bismuth citrate alone or with an antibiotic, and ranitidine hydrochloride (range: <1-2%). The safety profile of ranitidine bismuth citrate was thus comparable to that of ranitidine hydrochloride (Zantac), a drug with a well-established record of safety in clinical use.

Review article: safety of bismuth in the treatment of gastrointestinal diseases

Bismuth preparations are commonly used to treat a variety of gastrointestinal disorders, including peptic ulcers and dyspepsia. The safety profile of currently approved bismuth preparations, such as tripotassium dicitrato bismuthate (De-Nol), bismuth subsalicylate (Pepto-Bismol) and ranitidine bismuth citrate (Pylorid, Tritec), is excellent. Adverse reactions to these agents are mild, transient and infrequent, and reports of serious adverse reactions are rare. This, in part, reflects the low systemic bioavailability of bismuth from these medicines: less than 1% of the bismuth dose administered is absorbed. During repeated dosing with ranitidine bismuth citrate 200, 400 or 800 mg b.d. trough plasma bismuth concentrations remain well below 50 micrograms/L. After 4 weeks of treatment median concentrations of 3.4 micrograms/L or less were reported amongst 1210 duodenal ulcer patients receiving this new chemical entity, while mean concentrations of 5.1 micrograms/L (plasma) and 12.3 micrograms/L (blood) have been reported in two studies of patients receiving tripotassium dicitrato bismuthate 120 mg q.d.s. for 4 weeks. Transient peak plasma bismuth concentrations greater than 50 micrograms/L are observed 30-60 min after dosing with tripotassium dicitrato bismuthate in some patients, but are not associated with any toxic effects. After discontinuation of treatment with bismuth preparations its excretion in urine may continue for up to 3 months, by which time blood bismuth concentrations have declined to pretreatment values.

Qualitative cues in the discrimination of affine-transformed minimal patterns

An important factor in judging whether two retinal images arise from the same object viewed from different positions may be the presence of certain properties or cues that are 'qualitative invariants' with respect to the natural transformations, particularly affine transformations, associated with changes in viewpoint. To test whether observers use certain affine qualitative cues such as concavity, convexity, collinearity, and parallelism of the image elements, a 'same-different' discrimination experiment was carried out with planar patterns that were defined by four points either connected by straight line segments (line patterns) or marked by dots (dot patterns). The first three points of each pattern were generated randomly; the fourth point fell on their diagonal bisector. According to the position of that point, the patterns were concave, triangular (three points being collinear), convex, or parallel sided. In a 'same' trial, an affine transformation was applied to one of two identical patterns; in a 'different' trial, the affine transformation was applied after the point lying on the diagonal bisector was perturbed a short, fixed distance along the bisector, inwards for one pattern and outwards for the other. Observers' ability to discriminate 'same' from 'different' pairs of patterns depended strongly on the position of the fourth, displaced, point: performance varied rapidly when the position of the displaced point was such that the patterns were nearly triangular or nearly parallel sided, consistent with observers using the hypothesised qualitative cues. The experimental data were fitted with a simple probabilistic model of discrimination performance that used a combination of these qualitative cues and a single quantitative cue.

Evidence of type 2 herpes simplex infection in human coronary arteries at the time of coronary artery bypass surgery

OBJECTIVE

To examine histologically biopsies from the coronary arteries of patients undergoing coronary artery bypass grafting (CABG) for evidence of herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) antigen and to correlate the incidence with pathological and clinical data.

DESIGN

Sequential patients undergoing CABG in whom adequate tissue could be obtained for histology.

SETTING

University teaching hospital.

PATIENTS

Forty-six patients were enrolled. Thirty-one provided sufficient tissue and clinical information for the analysis.

METHODS

Biopsy material was collected in the operating room and prepared immediately for histology and electron microscopy. Slides were prepared by staining with hematoxylin and eosin, Masson trichrome, avidin biotin complex immunoperoxidase for HSV-1 and HSV-2 protein and specific DNA probes for HSV-1 and HSV-2 by hybridization. Clinical data were obtained in structured interviews.

RESULTS

Sixty-one per cent of biopsies demonstrated evidence of inflammation, 45% were positive for antigen to HSV-2 and only one to HSV-1. Significant positive correlations were detected between inflammatory cells in the biopsy and a recent history of cold sores and between the presence of the infiltrate and positivity to HSV-2 antigen.

CONCLUSION

A correlation exists between HSV-2 infection and the inflammatory response associated with atherosclerosis.

Calcium and colorectal epithelial cell proliferation in sporadic adenoma patients: a randomized, double-blinded, placebo-controlled clinical trial

BACKGROUND

The kinetics of colorectal epithelial cell proliferation is altered in patients at increased risk for colon cancer. Calcium administration ameliorates such proliferative changes in rodents. Findings in preliminary clinical trials have suggested similar effects in humans.

PURPOSE

A randomized, double-blind, placebo-controlled, clinical trial was designed to determine whether calcium supplementation will reduce the colorectal epithelial cell proliferation rate and normalize the distribution of proliferating cells within colorectal crypts (i.e., shift the zone of proliferation from the entire crypt to the lower 60% of the crypt, which is thought to be the normal proliferative zone of the crypt) in patients with sporadic adenomas.

METHODS

Sporadic adenoma patients (n = 193) were treated with placebo (n = 66), 1.0 g calcium (n = 64), or 2.0 g calcium (n = 63) daily for 6 months. Rectal mucosa biopsy specimens were obtained at base line and at 1-, 2-, and 6-month follow-up. Cell proliferation was measured by detection of S-phase-associated proliferating cell nuclear antigen by immunohistochemical methods. The cell proliferation rate, called labeling index (LI), was calculated as the proportion of labeled cells in the crypts. The deviation of the proliferative zone from the normal location in the lower 60% of the crypt was calculated as the proportion of labeled cells in the upper 40% of the crypt, called distributional index (phi h). The effects of calcium treatment on the LI and phi h were expressed as relative effects--(calcium follow-up/calcium base line)/(placebo follow-up/placebo base line). Calculations and inference testing of the relative effects were accomplished using a repeated-measures mixed model on log-transformed LI and phi h values. All statistical tests were two-sided.

RESULTS

Scorable biopsy specimens were obtained on 170 patients at base line, 164 at 1 month, 161 at 2 months, and 163 at 6 months. The difference in the change in the LI between the combined calcium groups and the placebo group was insignificant, with a relative effect of calcium versus placebo of 0.97 (P = .87). However, for the phi h, the relative effect of calcium versus placebo was 0.50 (P = .05) in the combined calcium groups, 0.56 (P = .16) in the 1.0-g calcium group, and 0.44 (P = .05) in the 2.0-g calcium group.

CONCLUSIONS

Calcium supplementation normalizes the distribution of proliferating cells without affecting the proliferation rate in the colorectal mucosa of sporadic adenoma patients.

IMPLICATIONS

These results support further study of whether alterations in colon cell proliferative kinetics represent true intermediate steps in colon carcinogenesis that can be used to investigate the etiology and prevention of, and whether a higher calcium consumption can reduce the risk of, colon cancer.

Combination of ranitidine and cisapride in the treatment of reflux oesophagitis

OBJECTIVE

To compare the efficacy of treatment for 8 or 12 weeks with a combination of 150 mg ranitidine twice daily plus 20 mg cisapride twice daily with ranitidine 150 mg twice daily alone in patients with moderate-to-severe reflux oesophagitis.

DESIGN

A double-blind, randomized, parallel-group clinical trial.

SETTING

Forty-two out-patient centres in the UK, Germany, Ireland, Denmark and South Africa.

PATIENTS

A total of 344 symptomatic patients with endoscopically confirmed reflux oesophagitis (Hetzel grade 3 or 4) were randomly assigned to receive the study medication.

INTERVENTIONS

Patients underwent a follow-up endoscopy after 8 weeks' treatment. Healing was defined as Hetzel grade 0 or 1 upon endoscopy. Patients with unhealed oesophagitis continued their allocated treatment regimen for a further 4 weeks before undergoing a repeat endoscopy.

MAIN OUTCOME MEASURES

The primary efficacy analysis was based on a comparison of 12-week cumulative healing rates between the two groups.

RESULTS

A statistically significant difference (P = 0.015) in the cumulative healing rate was observed between patients given ranitidine plus cisapride (82%) and those given ranitidine alone (71%). Oesophagitis in patients who received the combination was twice as likely to heal as that in patients who received ranitidine alone.

CONCLUSION

A combination of 150 mg ranitidine twice daily and 20 mg cisapride twice daily is a safe and effective treatment for moderate-to-severe reflux oesophagitis and offers increased efficacy over ranitidine alone.

Stress-related mucosal disease. Pathophysiology, prevention, and treatment

The advent of gastrointestinal endoscopy has allowed us to follow the morphologic results of severe stress on the gastrointestinal mucosa. It has become clear, however, that the presence of mucosal abnormalities does not always correlate with the presence of overt bleeding, or with the effect of bleeding on the overall outcome of such patients. In fact, the incidence of severe gastrointestinal hemorrhage, secondary to stress-related mucosal disease, has been decreasing over the past decade, as the care of these critically ill patients has improved. In patients who do have overt hemorrhage, however, the mortality rate is extremely high. It therefore remains the duty of the clinician to identify patients who are at high risk of having overt hemorrhage, and ensure that they receive adequate prophylactic therapy.

Does ranitidine affect blood alcohol concentrations?

No interaction occurs between ranitidine and alcohol when alcohol 0.3 g/kg or more is taken by either fed or fasted subjects. Ranitidine is associated with small increases (2-4 mg/dl) in blood alcohol concentrations in subjects given alcohol 0.15 g/kg under specific experimental conditions. Mean peak blood alcohol concentrations nevertheless remain low (< 20 mg/dl) after the amount, which is equivalent to about 3 oz of wine or 1 oz of 80-proof liquor. Such changes also occur when alcohol is ingested after different types of foods, and are smaller than the increases when it is drunk on an empty compared with a full stomach. The pharmacokinetic effect seen with ranitidine is without apparent clinical or social significance.

Culicoides responses to 1-octen-3-ol and carbon dioxide in salt marshes near Sea Island, Georgia, U.S.A

The semiochemicals carbon dioxide (CO2) and 1-octen-3-ol (octenol) were evaluated as attractants at several release rates, alone and in combination, for the major coastal species of biting midges in Georgia: Culicoides furens, C. hollensis and C. melleus (Diptera: Ceratopogonidae). The data show that CO2 is an effective attractant for the females of all three species, but each has a different response pattern. In contrast, octenol was an effective attractant only for C.furens, either alone or in combination with CO2; octenol had a repellent effect on the other two species. The combination of octenol and CO2 had a synergistic effect on the collections of C.furens.