The Hydrothermal Formation of Hydronium Alunite from Aqueous Al2(SO4)3 Solution and the Characterization of the Solid

Raman spectra have been measured for aqueous Al

Alcohol-induced free radicals in mice: direct toxicants or signaling molecules?

Tumor necrosis factor alpha (TNF-alpha) and free radicals are produced in early alcohol-induced liver injury. Recently, pathology caused by alcohol was blocked nearly completely in tumor necrosis factor alpha receptor 1 (TNF-R1) knockout mice. With this model, it is now possible to evaluate whether free radicals are directly toxic or act as redox regulators of TNF-alpha production. Specifically, if free radicals were directly toxic, a parallel decrease in free radicals and pathology in TNF-R1 knockout mice would be predicted. If they only affect TNF-alpha production, radicals would be expected to remain high while pathology is diminished. Accordingly, free radical production in TNF-R1 knockout mice was studied here. The enteral alcohol delivery model used mice lacking TNF-R1 (p55) and wild-type control C57Bl/6J mice. Animals received a liquid diet continuously with either ethanol or isocaloric maltose-dextrin as control for 4 weeks. Urine ethanol levels fluctuated from 10 to 500 mg/dL in a cyclic pattern in mice receiving ethanol. Ethanol elevated liver:body weight ratios, serum alanine transaminase (ALT) levels, and pathology scores in wild-type mice. These parameters were blunted nearly completely in TNF-R1 knockout mice. Ethanol treatment increased free radical production in wild-type mice compared with animals fed a high-fat control diet. There were no differences in intensity of free radical signals regardless of the presence or absence of TNF-R1; however, pathology differed markedly between these groups. These findings are consistent with the hypothesis that free radicals act as redox signals for TNF-alpha production and do not directly damage cells in early alcohol-induced hepatic injury.

Discrepancies in the detection and management of spontaneous pneumothorax: eight years after publication of guidelines

The British Thoracic Society (BTS) guidelines for the detection and management of spontaneous pneumothorax have been published for over eight years. The condition continues to be managed by surgical and medical staff, especially in DGH settings. This study evaluates any recognition and initial management discrepancies in a uncomplicated pneumothorax case and documents any deviancies from guidelines A study involving 112 staff was performed in a DGH. Results showed poor overall recognition of any published guidelines (32%) with only six staff correctly identifying BTS guidelines. There was no difference between medical and surgical or consultant and junior staff in the management strategy. A tendency to initially over-treat the condition with invasive chest drainage rather than aspiration was noted. Also, there was a tendency to underestimate the size of collapse using percentages. The need for greater appreciation of detection and management of this common condition remains extant and must be addressed aggressively.

Stability of human gallbladder bile: effect of freezing

In the present study, the stability of the most essential biliary parameters of human gallbladder bile at -18 degrees C was examined over several months. In 12 patients with gallstone disease (10 female, two male; 52.1+/-13.3 years of age), bile was obtained through fine needle puncture of the gallbladder under local anesthetic. The concentrations of total lipids, cholesterol, phospholipids and bile acids, and the cholesterol saturation index and crystal appearance time were determined before and after freezing over a mean period of 4.38+/-2.9 months. Gallbladder bile obtained by fine needle puncture has proved to be of excellent quality. The total lipid concentration was unchanged before (8.30+/-4.16 g/dL) and after freezing (9.16+/-4.54 g/dL, P=0.6027). The biliary cholesterol, phospholipids and bile acid concentrations, and cholesterol saturation index showed no statistically significant differences before and after freezing. A significant difference arises in the context of subdivision of the group to the nucleation time. Before freezing, most patients had a nucleation time between five and eight days, which shortened to between one and four days after thawing (P=0.0100). The authors conclude that, with the exception of the nucleation time, human gallbladder bile can be stored at -18 degrees C for four months with stability of major lipid components.

Influence of postweaning social isolation in the rat on brain development, conditioned behaviour and neurotransmission

There is substantial evidence that early life events influence brain development and subsequent adult behaviour and play an important role in the causation of certain psychiatric disorders including schizophrenia and depression. The underlying mechanism of the effects of these early environmental factors is still not understood. It is a challenge to attempt to model early environmental factors in animals to gain understanding of the basic mechanisms that underlie the long-term effects. This paper reviews the effects of rearing rats from weaning in social isolation and reports some recent results indicating hippocampal dysfunction. Isolation rearing in rats from weaning produces a range of persistent behavioural changes in the young adult, including hyperactivity in response to novelty and amphetamine and altered responses to conditioning. These are associated with alterations in the central aminergic neurotransmitter functions in the mesolimbic areas and other brain regions. Isolation-reared rats have enhanced presynaptic dopamine (DA) and 5-HT function in the nucleus accimbens (NAC) associated with decreased presynaptic 5-HT function in the frontal cortex and hippocampus. Isolation-reared rats have reduced presynaptic noradrenergic function in the hippocampus, but have enhanced presynaptic DA function in the amygdala. These neurochemical imbalances may contribute to the exaggerated response of the isolated rat to a novel stimulus or to stimuli predictive of danger, and isolation-induced behavioural changes. These changes have neuroanatomical correlates; changes which seem to parallel to a certain degree those seen in human schizophrenia. A greater understanding of the processes that underlie these changes should improve our knowledge of how environmental events may alter brain development and function, and play a role in the development of neuropsychiatric disorders.

Osteoporosis with low dose corticosteroids: contribution of underlying disease effects and discriminatory ability of ultrasound versus bone densitometry

OBJECTIVE

Corticosteroid use is associated with rapid bone loss, but the effect of low dose corticosteroids (CS) remains controversial and the extent to which increased fracture risk relates to quantitative effects, as reflected by change in bone mineral density (BMD), or to qualitative effects due to altered microarchitecture is unclear. Moreover the contribution of the underlying disease, for which CS are used, confounds the assessment of CS effects on bone. Our aim was to examine these effects of CS on bone.

METHODS

We measured BMD, quantitative ultrasound (US), and clinical and radiological disease indices in 76 patients with rheumatoid arthritis (RA) treated with or without low dose CS. Disease effects were quantitated using the Health Assessment Questionnaire and radiological scores.

RESULTS

BMD and US measures were significantly reduced in RA patients compared to age matched controls. Low dose CS use was associated with a further small but nonsignificant reduction in BMD, and US measures did not further discriminate CS effects on bone. Radiological score was an independent predictor of US measures, suggesting that in RA, calcaneal bone may reflect both systemic and local disease effects.

CONCLUSION

US did not appear to discriminate effects of low dose CS on bone better than BMD. However, underlying RA disease effects on bone are detectable by US. Quantitative US should be investigated for its utility in assessing disease activity or progress in RA.

Lack of response suppression follows repeated ventral tegmental cannabinoid administration: an in vitro electrophysiological study

Cannabinoid compounds have been reported to excite ventral tegmental neurons through activation of cannabinoid CB1 receptors. More recently, biochemical and whole-cell voltage-clamp studies carried out on CB1-transfected AtT20 cells have shown a rapid desensitization of these receptors following activation of protein kinase C by 4-alpha-phorbol. To investigate the possible physiological correlates of this phenomenon, we have studied the effects of repeated cannabinoid treatment on ventral tegmental area dopaminergic neuronal firing in vitro. Rat brain slices containing the ventral tegmental area were used for single-unit extracellular recordings. Only neurons meeting established electrophysiological and pharmacological criteria for dopaminergic neurons were used in the study (firing neurons were detected either using tungsten or glass microelectrodes). The high-affinity cannabinoid agonist HU210 produced a concentration-dependent increase in firing (1-15 microM; EC(50) approximately 7 microM). Initial HU210 exposure produced a significant increase in cell firing rate in the ventral tegmental area, with a maximum approximately 3.5-fold increase over pre-drug basal firing; a subsequent exposure to HU210 produced an approximately threefold increase over basal firing. Nevertheless, the duration and onset of excitation produced by the cannabinoid differed significantly between the first and second exposures; the first excitation lasted significantly longer than the second and required less time to reach a comparable change in firing rate. The increases in firing rate and the time to return to basal firing were not significantly different between exposures. Furthermore, the cannabinoid antagonist SR141716A completely prevented the HU210-induced excitation whilst having no effect on its own, thus indicating a CB1-receptor mediated mechanism for the observed increase in firing. Ventral tegmental area neurons are also excited by the GABA(A) receptor antagonist bicuculline. To assess the role of GABA in cannabinoid-mediated excitation, HU210 was added in the presence of bicuculline. HU210 did not affect the initial bicuculline-induced increase in firing, suggesting different sites of action for the two compounds. Our data fail to support previously reported findings using repeated cannabinoid administration and cell preparations. The maintained increase in DA drive elicited by the potent cannabinoid agonist HU210 in the in vitro ventral tegmental circuit could explain some of the behavioural properties of cannabinoids, such as the lack of tolerance for the psychotropic effects of marijuana seen in human users.

Predictors of response after laparoscopic splenectomy for immune thrombocytopenic purpura

BACKGROUND

Splenectomy has been shown to produce long term remission in patients with immune thrombocytopenic purpura (ITP). With the development of laparoscopic splenectomy, there is renewed interest in the surgical treatment of ITP. The aim of this study was to identify factors that are predictive of outcome after laparoscopic splenectomy for ITP.

METHODS

A case series of 67 consecutive patients with ITP undergoing laparoscopic splenectomy was reviewed. A positive response was defined as a postoperative platelet count greater than 150,000/ml requiring no maintenance medical therapy on follow-up evaluation. A chi-square test and a stepwise logistic regression analysis were performed for the following variables: age, gender, preoperative response to steroids, duration of disease, severity of preoperative bleeding, accessory spleens, and thrombocytosis on discharge.

RESULTS

At a median follow-up period of 38 months (range, 2-56 months), 52 patients (78%) had a positive response to laparoscopic splenectomy. Of the 15 patients (22%) who did not have a positive response, 11 were refractory and 4 relapsed. All relapses occurred in patients with a platelet count less than 150,000/microl at discharge. Patient age was the most significant predictive factor for success or failure of the operation. The median age of the responders (31 years; range, 19-71 years) was significantly lower than the median age of the nonresponders (49 years; range, 24-62; p < 0.001). Only 5.6% of those younger than 40 years did not have a positive response, compared with 42% of patients older than 40 years (p < 0.05). Patient age was significantly associated with outcome on univariable chi-square analysis (p = 0.001), and was the only significant factor on multivariable analysis (odds ratio, 2.65; 95% confidence interval, 1.71-4.1). Other significant predictors of outcome on univariable analysis were preoperative response to corticosteroids and platelet count on discharge.

CONCLUSIONS

A long-lasting response after splenectomy for ITP is more likely to occur in patients younger than 40 years of age. To avoid the long-term side effects of corticosteroid use, early surgical referral of younger patients with ITP should be considered.

Intraabdominal abscess rate after laparoscopic appendectomy

BACKGROUND

Studies suggest increased intraabdominal abscess (IA) rates following laparoscopic appendectomy (LA), especially for perforated appendicitis. Consequently, an open approach has been advocated. The aim of our study is to compare IA rates following LA performed by a laparoscopic surgery and a general surgical service within the same institution.

METHODS

Data of LA patients treated at Los Angeles County-University of Southern California (LAC-USC) Medical Center between March 1992 and June 1997 were reviewed. The main outcome measure was postoperative IA.

RESULTS

In all, 645 LA were reviewed. A total of 413 LA (285 acute, 61 gangrenous, 67 perforated appendicitis) were performed by three general surgical services (10 attendings). Ten abscesses occurred postoperatively (2.4%), 6 with perforated appendicitis. After the laparoscopic service was introduced, 232 standardized LA (126 acute, 46 gangrenous, 60 perforated) were performed by two attendings. One IA occurred (gangrenous appendicitis). The IA rate for perforated appendicitis was significantly lower on the laparoscopic service (P = 0.025). There was no difference in IA rates for acute and gangrenous appendicitis. There was no mortality in either group.

CONCLUSION

IA rate following LA for perforated appendicitis was significantly reduced on the laparoscopic service. Mastery of the learning curve and addition of specific surgical techniques explained this improved result. Therefore, laparoscopic appendectomy for complicated appendicitis may not be contraindicated, even for perforated appendicitis.

Pharmacological examination of contractile responses of the guinea-pig isolated ileum produced by mu-opioid receptor antagonists in the presence of, and following exposure to, morphine

We have assessed the potential of several mu-opioid receptor antagonists to elicit a response in the guinea-pig isolated ileum in the presence of, and following overnight exposure to, morphine. Naloxone, D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH(2) (CTOP), (-)-5, 9alpha-diethyl-2-(3-furyl-methyl)-2'-hydroxy-6,7-benzomorphan (MR2266), but not D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH(2) (CTAP), produced a transient inhibition of electrically-evoked contractions of the guinea-pig ileum. The effect of 1 microM CTOP, but not that to MR2266, was inhibited by 1 microM somatostatin. Naloxone (0.3 microM), CTOP (3 microM), CTAP (3 microM) and MR2266 (0.3 microM) antagonized the inhibitory effect of morphine on electrically-evoked contractions of the guinea-pig to a similar degree and, following 60 min exposure to morphine, produced non-sustained contractions. The response to 3 microM CTOP was significantly smaller than that to 3 microM CTAP. None of the antagonists produced a response in the absence of morphine. Following overnight exposure of the ileum to 0.3 microM morphine (4 degrees C), and repeated washing to remove the agonist, all four antagonists elicited non-sustained contractions. However, the responses to 3 microM CTOP and 0.3 microM MR2266 were significantly smaller than those elicited by 0.3 microM naloxone and 3 microM CTAP. Somatostatin (1 microM) significantly reduced naloxone-induced contractions, but not those to CTAP. While all four mu-opioid antagonists elicited contractions in the presence of, and following prolonged exposure to, morphine, differences between them were noted which may be a consequence of non-opioid actions.

Endoscopic valvuloplasty for GERD

BACKGROUND

The transoral, endoscopic route has been suggested as a possible approach for the correction of severe gastroesophageal reflux. Such a procedure would involve no mobilization of the cardia or other structures. The optimal placement, number, and configuration of sutures remains undefined.

METHODS

With the use of a previously developed endoscopic sewing machine, this study was undertaken in baboons with two suture arrangements immediately below the lower esophageal sphincter. A linear arrangement (group I) and a circular arrangement (group II) were compared. During the 6 months after the procedure, the animals were evaluated using manometry, fluoroscopic barium swallow, upper gastrointestinal endoscopy, and a pressure volume test.

RESULTS

A significant increase in lower esophageal sphincter length was demonstrated only in group II (p = 0. 010). A significant increase in lower esophageal sphincter pressure was demonstrated only in group I animals (p = 0.008). The abdominal length increased in group I (p = 0.004) and group II (p = 0.004). The yield pressure and yield volume did not differ significantly from those measured previously in control animals. No evidence of reflux, stricture formation, esophagitis, or other pathology was noted.

CONCLUSIONS

Some manometric parameters associated with gastroesophageal reflux are altered by the endoscopic placement of sutures below the gastroesophageal junction, with no associated serious complications.

The effect of imputation of exposure estimates on the association between fine particulate matter and mortality

PURPOSE: The Harvard Six Cities Study (HSCS) found a small but significant association between daily PM2.5 and daily mortality count. The HSCS findings have been used as the basis for new EPA regulations, requiring lower levels of PM2.5. We feel that there are unresolved issues regarding the HSCS that should be fully evaluated prior to its findings being used as the basis of new regulation, including how the extent and method of imputing exposure data affect the association with daily mortality counts.METHODS: We examined the association between PM2.5 levels and daily mortality count, comparing the results from the HSCS methods with results based on an alternate imputation method, and with non-missing data.RESULTS: Overall, approximately 30% of the data points used in the HSCS were imputed. The method of imputation affected the association between particulate matter and mortality to a substantial degree in most of the cities. When the model using the HSCS method was compared to the model using the alternate method, in two areas the coefficients decreased substantially and lost significance. In two areas they changed little; in one area it rose substantially and became significant; and in one area it declined substantially but remained significant. When compared to the model based on the non-missing data, somewhat different patterns were observed. In both comparisons there were some large changes in the magnitude of the effect, but these were not consistent with the model used.CONCLUSIONS: We are concerned about the degree of data imputation and the effect that the method of imputation has on the association between particulate matter levels and mortality. In the case of the HSCS it appears that the imputed data are more strongly associated with the outcome than other methods of imputation and than the non-missing data. The reasons for these observations are not readily apparent, but the differences in effect should be explored and explained.

UV-induced inhibition of transcription involves repression of transcription initiation and phosphorylation of RNA polymerase II

Cells from patients with Cockayne syndrome (CS) are hypersensitive to DNA-damaging agents and are unable to restore damage-inhibited RNA synthesis. On the basis of repair kinetics of different types of lesions in transcriptionally active genes, we hypothesized previously that impaired transcription in CS cells is a consequence of defective transcription initiation after DNA damage induction. Here, we investigated the effect of UV irradiation on transcription by using an in vitro transcription system that allowed uncoupling of initiation from elongation events. Nuclear extracts prepared from UV-irradiated or mock-treated normal human and CS cells were assayed for transcription activity on an undamaged beta-globin template. Transcription activity in nuclear extracts closely mimicked kinetics of transcription in intact cells: extracts from normal cells prepared 1 h after UV exposure showed a strongly reduced activity, whereas transcription activity was fully restored in extracts prepared 6 h after treatment. Extracts from CS cells exhibited reduced transcription activity at any time after UV exposure. Reduced transcription activity in extracts coincided with a strong reduction of RNA polymerase II (RNAPII) containing hypophosphorylated C-terminal domain, the form of RNAPII known to be recruited to the initiation complex. These results suggest that inhibition of transcription after UV irradiation is at least partially caused by repression of transcription initiation and not solely by blocked elongation at sites of lesions. Generation of hypophosphorylated RNAPII after DNA damage appears to play a crucial role in restoration of transcription. CS proteins may be required for this process in a yet unknown way.

Multi-neuronal recordings reveal a differential effect of thapsigargin on bicuculline- or gabazine-induced epileptiform excitability in rat hippocampal neuronal networks

The present study was performed to investigate the effects of depleting intracellular Ca(2+) stores on bicuculline- or gabazine-induced epileptiform excitability. Studies were performed on monolayer rat hippocampal neuronal networks utilising a system that allowed simultaneous multiple extracellular single-unit recordings of neuronal activity. Hippocampal neuronal networks were prepared from enzymatically dissociated hippocampi from 18-day-old fetal Wistar rats. The cells were cultured in Neurobasal medium with B27 serum-free supplements directly onto the surface of planar multiple microelectrode arrays with a central recording array of 64 (4 x 16) indium-tin thin-film recording electrodes. All cells recorded at 21 days-in-vitro exhibited spontaneous discharge activity with firing rates between 0.3-30.7 Hz. gamma-aminobutyric acid (GABA) produced a concentration-dependent decrease in firing (EC(50)=9.1 microM) which could be blocked by pre-application of bicuculline methobromide (10 microM). Addition of the GABA(A)-receptor antagonists gabazine (10 microM) or bicuculline (10 microM) resulted in the rapid generation of synchronised bursting within all the cells recorded. Bicuculline exhibited heterogeneity of action on firing rate, whereas gabazine always increased firing. Pre-incubation with thapsigargin, which depletes intracellular calcium stores, resulted in a decrease in the amount of neuronal excitation produced by bicuculline, but not by gabazine, suggesting that bicuculline-induced neuronal excitation requires release of Ca(2+) from intracellular stores.

Pharmacological comparison of the effect of ibogaine and 18-methoxycoronaridine on isolated smooth muscle from the rat and guinea-pig

Ibogaine and 18-methoxycoronaridine are naturally occurring alkaloids reported to possess antiaddictive properties in several models of drug dependence. We have examined their effect at mu-opioid receptors regulating neurogenic contractions of several smooth muscle preparations and also against spontaneous contractions of the rat isolated portal vein. Ibogaine (pIC(50) 5.28) and 18-methoxycoronaridine (pIC(50) 5.05) caused a concentration-dependent inhibition of cholinergic contractions of the guinea-pig ileum which was not affected by the opioid receptor antagonist naloxone (1 microM). In the rat isolated vas deferens ibogaine and 18-methoxycoronaridine caused a concentration-dependent enhancement of purinergic contractions. Both agents (30 microM) caused a 3 - 5 fold rightward displacement of DAMGO-induced inhibition of purinergic contractions, but similar effects were observed for ibogaine against alpha(2)-adrenoceptor-mediated inhibition of neurogenic responses. In the guinea-pig isolated bladder both ibogaine (10 microM) and 18-methoxycoronaridine (10 microM) caused a 2 fold increase in the purinergic component of neurogenic contractions without significantly altering cholinergic contractions or responses to exogenous ATP. In contrast, ibogaine (1 - 30 microM), but not 18-methoxycoronaridine, caused a concentration-dependent enhancement of spontaneous contractions of the rat isolated portal vein. In summary, while ibogaine and 18-methoxycoronaridine modulated electrically-evoked contractions in the three preparations examined, we have no evidence for a selective interaction with pre-junctional mu-opioid receptors. The pronounced enhancement of purinergic contractions produced by both agents is a novel finding and worthy of further investigation.

Enhancement of the migration of metastatic human breast cancer cells by phosphatidic acid

Phosphatidic acid (PA), lysophosphatidic acid (LPA), and sphingosine 1-phosphate (SPP) are naturally occurring phospholipids which induce a variety of effects as extracellular messengers. In this study, we compared the effects of these phospholipid signaling molecules on the migration of invasive and noninvasive breast cancer cell lines, an index of the metastatic potential of these cells. As previously demonstrated, invasive MDA-MB-231 breast cancer cells exhibited increased constitutive (nonstimulated) migration in comparison to poorly invasive MCF-7 cells. Phosphatidic acid employed at nanomolar concentrations markedly potentiated migration of the invasive cells but had no effect on migration of either the noninvasive MCF-7 cells or nonneoplastic human epithelial cells. Lysophosphatidic acid and sphingosine 1-phosphate inhibited both the directed (chemotactic) and random (chemokinetic) migration of MDA-MB-231 cells. Experiments were undertaken to characterize the signaling pathway involved in constitutive and PA-stimulated migration of MDA-MB-231 cells. The tyrosine kinase inhibitors staurosporine and genistein inhibited constitutive and PA-induced migration in a dose-dependent manner, consistent with a role for tyrosine phosphorylation in the migratory response. In addition, the phosphatidylinositol (PI) 3' kinase inhibitors wortmannin and LY294002 strongly inhibited both the constitutive and PA-stimulated migration of the invasive breast cancer cells, indicating that PI-3' kinase plays an important role in the metastatic migration of breast cancer cells. Finally, PA-induced migration of MDA-MB-231 was markedly attenuated by pretreatment of cells with Clostridium difficile Toxin B, pertussis toxin and suramin, implying a role for a Gi receptor-dependent process involving activation of the small GTP-binding protein Rho. Since an enhanced ability to migrate heightens the metastatic potential of cells within solid tumors, our results suggest that the metastatic capabilities of breast cancer cells may be enhanced by a receptor-driven cellular process initiated by phosphatidic acid or related lipid phosphate messengers.

Electrophysiological effects of opioid receptor activation on Syrian hamster suprachiasmatic nucleus neurones in vitro

Entrainment of the dominant circadian pacemaker localised to the hypothalamic suprachiasmatic nuclei (SCN) is mediated partially via the indirect retino-geniculo-hypothalamic projection to the SCN, which is presumed to utilise enkephalin and other neurotransmitters, to modulate circadian rhythmicity. In the present study, we have investigated electrophysiologically the currently unknown functional effects of enkephalin, and another opioid receptor agonist morphine, on hamster SCN neuronal activity in vitro. Basal or N-methyl-D-aspartate-evoked firing rates of SCN neurones were generally unresponsive (86%) to the opioid receptor agonists leucine-enkephalin, methionine-enkephalin, or morphine. Washout of the enkephalins or morphine resulted in a rebound excitatory response ("withdrawal activation") in 39% of neurones tested. Withdrawal activation was also elicited by administration of the opioid receptor antagonist naloxone, following pre-exposure to morphine, in 59% of neurones tested. These withdrawal responses were blocked or attenuated by the alpha2-adrenoceptor agonist clonidine, results which suggest a functional interaction exists between opioid receptors and alpha2-adrenoceptors in the SCN. Our observations show that opioid receptor agonists are largely devoid of actions on normal hamster SCN circadian pacemaker activity, while the occurrence of withdrawal responses may have implications on circadian function during withdrawal from opiate abuse.

[The physiopathological basis for Zenker's diverticulum]

Disorders of the pharyngoesophageal phase of swallowing, including Zenker's diverticulum, result from alterations of the neuromuscular events involved in chewing, initiation of swallowing, and propulsion of the material from the oropharynx into the cervical esophagus. Although a number of mechanisms have been postulated to explain the genesis of Zenker's divertcula, including sphincter incoordination, swallowing against a closed UES, failed UES relaxation, and a hypertensive spastic upper sphincter, recent evidence suggests that the pathophysiology of Zenker's diverticula involves altered compliance of the cricopharyngeal segment. Manometric relaxation may occur in the absence of anatomic opening. Incoordination is uncommon. Altered compliance is detectable with specialized cricopharyngeal manometric recording as impaired sphincter opening or a raised intrabolus pressure. Both return to normal following diverticulectomy and cricopharyngeal myotomy.

Microstimulation of movements from cerebellar-receiving, but not pallidal-receiving areas of the macaque thalamus under ketamine anaesthesia

The motor thalamic areas receiving input from the globus pallidus (VA) and the cerebellar nuclei (VL) appear to have different roles in the generation and guidance of movements. In order to further test these differences, we used electrical stimulation to map the ventro-anterior and ventro-lateral nuclei of the thalamus in three ketamine anaesthetised monkeys. Movements were readily evoked from VL at currents of down to 10 microA. The movements were typically multijoint, and stimulation could evoke arm and trunk or arm and facial movement at the same current threshold. Evoked arm movements often involved multiple joints, with or without finger movements. Facial movements included the lips, tongue, jaw, eyebrows and, occasionally, the eyes. The thalamic map was topographic, but complex with at least two separate regions related to arm movement. Very few sites within the VA could stimulate movement, even at high currents. We therefore suggest that the cerebellar projections to motor regions of the cortex, which pass through the VL thalamic nuclei, have a different relationship and are closer to movement execution than the projections from basal ganglia via the ventro-anterior nucleus.

Treatment of a malignant esophageal perforation with a prototype conical Wallstent

A 60-year-old man with a malignant esophageal perforation could not be treated by conventional covered metallic stents because the upper esophagus was dilated. The perforation was eventually closed by deployment of a prototype, conical covered Wallstent.

Computed tomography and positron emission tomography in the pre-operative staging of oesophageal carcinoma

Because patients with carcinoma of the oesophagus usually present with advanced disease and surgery has a high mortality with cure in less than 10% of patients, pre-operative staging to select appropriate patients is necessary. Computed tomography (CT) plays an important role in staging but has well recognized limitations. Positron emission tomography (PET) which provides physiological information may therefore be a better alternative.

OBJECTIVE

To compare the findings of CT and positron emission tomography (PET) with 2-[18fluorine]-fluoro-2-deoxy-D-glucose (FDG) in the pre-operative staging of oesophageal carcinoma.

MATERIALS AND METHODS

Twenty-five patients with biopsy proven oesophageal cancer had pre-operative staging using CT and FDG-PET. The studies were read independently and full histological confirmation was obtained in 19 patients. Four parameters were studied: the primary tumour, peri-oesophageal lymph nodes, liver metastases and left gastric lymph nodes.

RESULTS

PET visualized all primary tumours; CT missed one. CT identified 4/8 patients with involved peri-oesophageal nodes and PET 3/8. CT identified 5/9 patients with left gastric adenopathy and PET 1/9. PET visualized a liver metastasis missed on CT and appeared to be better in assessing residual tumour. PET did identify distant metastases not seen on CT in seven patients.

CONCLUSIONS

The two techniques are both effective in showing the primary tumour and about equally sensitive in the demonstration of peri-oesophageal nodes. PET is probably more sensitive than CT for the detection of distant metastases.

Selective potentiation by ouabain of naloxone-induced withdrawal contractions of isolated guinea-pig ileum following acute exposure to morphine

1. Ouabain, an inhibitor of Na+/K+ ATPase induces the release of acetylcholine from central and myenteric cholinergic neurones principally due to partial depolarization of the cell membrane. The effect of ouabain has been examined on neurogenic contractions in the guinea-pig ileum arising from either electrical field stimulation or from naloxone in morphine-exposed preparations. 2. Guinea-pig isolated ileum preparations were stimulated transmurally (0.1 Hz, 0.3 ms, 200 mA) to elicit contractions of the myenteric plexus-longitudinal smooth muscle. 3. Incubation with morphine (0.3 microM, 60 min) was followed by naloxone (1 microM) which produced withdrawal contractions in 16/26 preparations (median of 10.7 [2.2-40.0]% of a maximal contracture to KCl (60 mM)). 4. In parallel experiments, ouabain (1 microM) was added to the tissue before exposure to morphine (0.3 microM, 60 min). Naloxone (1 microM) subsequently displayed a withdrawal contraction in all 26/26 tissues (57.9 [30.5-151.7]% of a maximal contracture to KCl (60 mM). 5. Ouabain neither affected the concentration-dependent contractions of guinea-pig ileum produced by carbachol nor the inhibition of electrically-evoked contraction produced by morphine (0.3 microM). 6. The muscarinic antagonist atropine (0.1 microM) antagonized control naloxone withdrawal responses. The atropine resistant component, evident in ouabain-treated tissues, was blocked by SR140333((S)1-[2-[3-(3,4-dichlorophenyl)-1-(3-isopropoxyphenyla cetyl)piperidin-3-yl]ethyl]-4-phenyl-1-azoniabicyclo[2.2. 2]-octane, chloride), a substance P antagonist. 7. Clonidine (alpha2-adrenoceptor agonist) inhibited electrically-evoked contractions. Exposure to the alpha2-adrenoceptor antagonist RX811059 (2-(2-ethoxy-1,4-benzodioxan-2-yl)-2-imidazoline), resulted in a contracture which was not significantly enhanced by ouabain (1 microM). 8. Ouabain selectively potentiates the naloxone-induced withdrawal contraction following acute exposure to morphine the major components of which are mediated by both acetylcholine and substance P.

Physical map of human 6p21.2-6p21.3: region flanking the centromeric end of the major histocompatibility complex

We have physically mapped and cloned a 2.5-Mb chromosomal segment flanking the centromeric end of the major histocompatibility complex (MHC). We characterized in detail 27 YACs, 144 cosmids, 51 PACs, and 5 BACs, which will facilitate the complete genomic sequencing of this region of chromosome 6. The contig contains the genes encoding CSBP, p21, HSU09564 serine kinase, ZNF76, TCP-11, RPS10, HMGI(Y), BAK, and the human homolog of Tctex-7 (HSET). The GLO1 gene was mapped further centromeric in the 6p21.2-6p21.1 region toward TCTE-1. The gene order of the GLO1-HMGI(Y) segment in respect to the centromere is similar to the gene order in the mouse t-chromosome distal inversion, indicating that there is conservation in gene content but not gene order between humans and mice in this region. The close linkage of the BAK and CSBP genes to the MHC is of interest because of their possible involvement in autoimmune disease.

Responses to neuropeptide Y in adult hamster suprachiasmatic nucleus neurones in vitro

We investigated the effects of neuropeptide Y and related analogues on the extracellularly recorded spontaneous firing rate activity of adult Syrian hamster suprachiasmatic nucleus neurones in vitro. Sixty-seven neurones were tested with neuropeptide Y: 45% were suppressed, 4% were activated, and the remaining 51% were unresponsive. These responses were not blocked by the GABA receptor antagonist bicuculline, indicating that neuropeptide Y-evoked responses did not appear to be dependent on GABA(A) receptor activation. We tested the effects of the neuropeptide Y Y1 receptor agonist [Leu31, Pro34]neuropeptide Y and the neuropeptide Y Y2 receptor agonist neuropeptide Y-(13-36) on nine cells suppressed by neuropeptide Y in order to determine the receptor subtype(s) mediating the effects of neuropeptide Y. Four of nine cells were suppressed by [Leu31, Pro34]neuropeptide Y only, one of nine was suppressed by neuropeptide Y-(13-36) only, two of nine were suppressed by both compounds, while the remaining two cells did not respond to either compound. These data suggest that neuropeptide Y can modulate suprachiasmatic nucleus function directly, without recruitment of GABA(A) interneurones. Further, our results indicate that neuropeptide Y may act on more than one receptor subtype within the adult hamster suprachiasmatic nucleus.

A pilot study of needs assessment in acute psychiatric inpatients

The needs of acute psychiatric patients have been less studied than those of long-term patients. A pilot study of needs assessment using the MRC Needs for Care Assessment Schedule is reported in 35 consecutive acute inpatients who had been in hospital for 1 month or more. Unmet clinical needs included treatment of drug side effects and dangerous and socially embarrassing behaviour. Unmet social needs were widespread and included household shopping, cooking meals, occupation and money management. Although the MRC Needs for Care Assessment was found unsuitable for assessing needs in very acutely ill patients whose mental status was rapidly changing, we did find it a useful instrument in more stable acute patients, both on an individual basis and for identifying service underprovision.

A paracrine role for myoepithelial cell-derived FGF2 in the normal human breast

We have studied separated normal human breast epithelial and myoepithelial cells for the presence of basic fibroblast growth factor (FGF2) and its receptors, both low (heparan sulfate proteoglycans) and high affinity (FGFR1), and for the effects of FGF2 on the proliferation of both cell types. Our results indicate that these cells differ markedly in their synthesis and response to FGF2. We found, using PCR of purified cell populations, mRNA for FGF2 only in the myoepithelial cells, whereas immunostaining and Western blotting results demonstrated the presence of FGF2 protein in both epithelial and myoepithelial cells. FGF2 had no effect on the proliferation of myoepithelial cells, but it did maintain the survival of the separated epithelial cells in low serum and stimulate their growth in 5% and 10% FCS. Immunostainable FGFR1 was present in epithelial cells and, to a lesser extent, in myoepithelial cells. Low-affinity binding sites for FGF2 were synthesized by epithelial and myoepithelial cells, but myoepithelial cells possessed a greater proportion of higher-affinity heparan sulfate proteoglycans. These results indicate that myoepithelial cell-derived FGF2 may be an important paracrine factor controlling epithelial cell survival and growth in the normal human breast.

Mechanical effect of the Angelchik prosthesis on the competency of the gastric cardia: pathophysiologic implications and surgical perspectives

The Angelchik prosthesis appears to be effective in preventing gastroesophageal reflux, although its precise mechanism of action remains controversial. In a unique in vitro model, 10 freshly harvested canine esophagogastric specimens were tested for their ability to remain competent against challenges of intragastric pressure under controlled conditions of intra-abdominal pressure, longitudinal esophageal tension, lower esophageal sphincter pressure and overall length and circumference of the cardia (measure of gastric dilatation). Competency of the specimen was assessed by stepwise variation in the overall length of the sphincter, while keeping constant intraabdominal pressure (20 cm H2O), intragastric pressure (20 cm H2O), esophageal tension (physiologic), lower esophageal sphincter pressure (15 cm H2O) and degree of gastric dilatation (3 cm). With each specimen serving as its own control, the effect produced by the application of an Angelchik prosthesis was evaluated. Results consistently demonstrated that at any lower esophageal sphincter length the percent of competency was increased when the prosthesis was applied (P < 0.01). The findings indicate that the Angelchik prosthesis controls reflux by preventing unfolding of the lower esophageal sphincter when challenged by intragastric pressure.

The challenge of genuine power sharing in participatory research: the gap between theory and practice

Participatory research is often suggested as a strategy to overcome power imbalances between researchers and research "subjects" because it values equally the knowledge of each individual who participates in the project. However, there is little documentation of the dilemmas that may arise when a complex community service organization attempts to engage in participatory research. In our experience of a participatory research project with multiple partners, power imbalances arose from organizationally based perspectives that were unaccounted for in the participatory research literature, demonstrating that power is a complex and elusive factor in establishing equal relations.

Palliation of malignant dysphagia: an alternative to surgery

This paper presents the results of palliative treatment of 474 patients with malignant dysphagia. Laser produces good relief of symptoms but requires frequent repetition. Self-expanding metal stents provide one-off relief of dysphagia but do have complications. A randomised trial of laser versus covered and uncovered metal stents has demonstrated improved relief of dysphagia of stents over laser, but highlighted the problems at the cardia when stents are used. Chemotherapy in patients with advanced adenocarcinoma using epirubicin, cisplatin and 5-fluorouracil produces a response in two-thirds of cases, with relief of dysphagia and possible increase in survival. A treatment plan for palliation of patients with malignant dysphagia is presented.

Iso- or antiperistaltic anastomosis: does it matter?

To assess the importance of gastrojejunal anastomoses being performed in an isoperistaltic manner, 25 rats underwent solid and liquid gastric emptying studies before and at 1, 2, 3, 4, 8, 12 and 16 weeks after a Polya-type gastrectomy. No differences between the two anastomotic directions were evident, either in the deaths associated with post-operative gastric dilatation, or in the rates of solid and liquid gastric emptying following surgery.

Orbitofrontal cortex neurons: role in olfactory and visual association learning

1. The orbitofrontal cortex is implicated in the rapid learning of new associations between visual stimuli and primary reinforcers such as taste. It is also the site of convergence of information from olfactory, gustatory, and visual modalities. To investigate the neuronal mechanisms underlying the formation of odor-taste associations, we made recordings from olfactory neurons in the orbitofrontal cortex during the performance of an olfactory discrimination task and its reversal in macaques. 2. It was found that 68% of odor-responsive neurons modified their responses after the changes in the taste reward associations of the odorants. Full reversal of the neuronal responses was seen in 25% of these neurons. Extinction of the differential neuronal responses after task reversal was seen in 43% of these neurons. 3. For comparison, visually responsive orbitofrontal neurons were tested during reversal of a visual discrimination task. Seventy-one percent of these visual cells showed rapid full reversal of the visual stimulus to which they responded, when the association of the visual with taste was reversed in the reversal task. 4. These demonstrate that of many orbitofrontal cortex olfactory neurons on the taste with which the odor is associated. 5. This modification is likely to be important for setting the motivational value of olfactory for feeding and other rewarded behavior. However, it is less complete, and much slower, than the modifications found or orbit frontal visual during visual-taste reversal. This relative inflexibility of olfactory responses is consistent with the need for some stability is odor-taste associations to facilitate the formation and perception of flavors.

Responses of neurons in the primate taste cortex to the glutamate ion and to inosine 5'-monophosphate

To investigate the neural encoding of glutamate taste in the primate, recordings were made from taste responsive neurons in the cortical taste areas in macaques. Most of the neurons were in the orbitofrontal cortex taste area, with a small number in adjacent taste areas. First, it was shown that single neurons that had their best responses to sodium glutamate also had good responses to glutamic acid. The correlation between the responses to these two tastants was higher than between any other pair of tastants, which included glucose (sweet), sodium chloride (salty), HCl (sour), and quinine HCl (bitter). Accordingly, the responsiveness to glutamic acid clustered with the response to monosodium glutamate in a cluster analysis with this set of stimuli, and glutamic acid was close to sodium glutamate in a space created by multidimensional scaling. Second, it was shown that the responses of these neurons to the nucleotide umami tastant inosine 5'-monophosphate were more correlated with their responses to monosodium glutamate than to any prototypical tastant. Third, concentration response curves showed that concentrations of monosodium glutamate as low as 0.001 M were just above threshold for some of these neurons. Fourth, neurons have not yet been found in this cortical region that showed synergism of monosodium glutamate and the nucleotide inosine 5'-monophosphate: it was shown that mixtures of 0.0001 M inosine 5'-monophosphate with different concentrations (0.001, 0.01, and 0.1 M) of monosodium glutamate did not have a greater effect than the monosodium glutamate alone. Fifth, some neurons in the orbitofrontal region, which responded to monosodium glutamate and other food tastes, decreased their responses after feeding with monosodium glutamate to behavioural satiety. In some cases this reduction was sensory-specific. These findings show that the taste neurons activated by monosodium glutamate can also be activated by other umami tastants, including glutamic acid and the nucleotide inosine 5'-monophosphate. The responses to these umami tastants were more similar to each other than to any of the other prototypical tastants, providing evidence that in this system umami is encoded differently from the other tastants. Moreover, the findings with these tastants provide additional evidence that the responses to monosodium glutamate are not due just to activation of a sodium taste channel.

Gallstone recurrence after successful dissolution therapy

After successful dissolution therapy of cholesterol gallbladder stones bile again becomes supersaturated and recurrent gallstones may develop. Three different postdissolution treatments [500 mg ursodeoxycholic acid (UDCA) per day (N = 14, group I), 100 mg aspirin per day (N = 14, group II) and diet (N = 15, group III) versus a control group (no treatment, N = 15, group IV) aimed at preventing recurrence of gallstones were investigated in a prospective, randomized study in 58 gallstone patients (33 female, 25 male) after complete stone clearance. Bile samples (prior to dissolution therapy and at stone recurrence) were investigated for biliary cholesterol (C), phospholipids (PL), total bile acid concentration (BA), cholesterol saturation index (CSI), total lipid concentration (TLC), total biliary protein concentration (TP), and nucleation time (NT). In group IV multiple gallstones tended to recur more often than solitary stones (66.7% vs 16.7%) whereas in groups I-III only solitary stones recurred. Recurrent gallbladder stones were detectable in 10 patients (eight patients in group IV and one each in groups I and II, respectively) within one year after dissolution and in two patients (one each in groups III and IV, respectively) after 15 months. Furthermore, the probability of stone recurrence was significantly higher in untreated patients as compared to treated patients. In nine (group IV) of 12 patients with recurrent stones NT, C, CSI, PL, BA, TLC, TP, and bile acid spectrum remained nearly unchanged as compared to their pretreatment values, whereas in three (groups I-III) of 12 cases a decrease in C, CSI, and TP was observed during therapy. However, in each of these three patients, initial and after-treatment TP was significantly higher and NT shorter as compared to groups I-IV. Furthermore, in these cases (N = 3) NT was prolonged, whereas no significant changes were found in PL, BA, TLC, and bile acid spectrum. Recurrence of gallstones, which seems to occur more likely in patients with multiple stones as compared to solitary stones, will happen in the early stage after stone clearance, again causing biliary pain. UDCA, aspirin or diet will reduce the probability for recurrent stones after complete gallstone dissolution.

Combined bile acid therapy is more effective on biliary lipids and dissolution rates than monotherapy after gallstone lithotripsy

BACKGROUND

Accurate sampling of gallbladder bile for biliary analysis is essential for determining any potential difference between combined bile acid therapy and monotherapy in gallstone patients.

METHODS

In 104 gallstone patients undergoing extracorporeal shock wave lithotripsy with following bile acid therapy [either chenodeoxycholic acid (500 mg/day) and ursodeoxycholic acid (500 mg/day), group I (n = 53), or ursodeoxycholic acid alone (1000 mg/day), group II (n = 51)], bile samples, obtained by direct fine needle puncture of the gallbladder, were investigated for biliary lipids, total biliary protein concentration, and nucleation time before and after 12 months of bile acid therapy.

RESULTS

Initially, a negative correlation was found between nucleation time and number of gallstones and between total biliary protein concentration and nucleation time (r = -0.52 and r = -0.49 in group I vs r = -0.56 and r = -0.51 in group II, p < 0.01 in each group). The correlation between total biliary protein concentration and nucleation time was also found after 12 months of bile acid treatment (r = -0.54 in group I vs r = -0.47 in group II, p < 0.01 in each group). In group I, the decrease in cholesterol saturation index, biliary cholesterol, cholic acid, deoxycholic acid, and total protein concentration was more pronounced than in group II (p < 0.01). The same effect was found concerning the prolongation of nucleation time (p < 0.01). Furthermore, dissolution rates were higher in group I compared with group II (80.4 vs 69.0%, p < 0.01).

CONCLUSION

In gallstone patients, combined therapy with urso- and chenodeoxycholic acid is superior to either ursodeoxycholic acid alone or biliary parameters in bile samples obtained by direct fine needle puncture of the gallbladder.

Solitary versus multiple gallstones: the importance of total biliary protein concentration and other factors

BACKGROUND

Nucleating and antinucleating factors play an important role in the pathogenesis of cholesterol crystal nucleation.

PATIENTS AND METHODS

In 88 gallstone patients (59 female, 29 male) bile was examined for total biliary protein and glycoprotein concentration, nucleation time and cholesterol saturation index. Gallstone density was measured by in vivo computed tomography.

RESULTS

Total biliary protein concentration was positively correlated with the number of gallstones (r = 0.84, p < 0.01) and higher in radiologically detectable isodense gallstones as compared to non-isodense stones (p < 0.01). A negative correlation between total biliary protein concentration, glycoprotein concentration and nucleation time was observed (r = -0.45, p < 0.01 and r = -0.49, p < 0.05). Nucleation time was significantly shorter in the case of multiple versus solitary stones (2.6 +/- 1.3 versus 8.5 +/- 3.0 days, p < 0.01). Cholesterol saturation index and biliary cholesterol concentration were similar in both cases, however a negative correlation between cholesterol saturation index and stone density (r = -0.79, p < 0.01) was found. No correlation was found between cholesterol saturation index and nucleation time (r = -0.04, p > 0.1), independent of gallstone number. None of the examined parameters was related to sex, age, weight or gallbladder function.

CONCLUSIONS

Multiple gallbladder stones seem to be associated with shorter nucleation time and higher biliary concentrations of total protein and glycoprotein than solitary stones.

Plastic-covered metallic endoprostheses in the management of oesophageal perforation in patients with oesophageal carcinoma

OBJECTIVE

To evaluate the role of plastic-covered self-expanding metallic endoprostheses in patients with oesophageal perforation occurring during endoscopically guided dilatation prior to laser treatment for malignant obstruction.

SUBJECTS AND METHODS

Six patients with oesophageal perforation following laser treatment for malignant obstruction were treated. Four patients received the polyurethane-covered Wallstent endoprosthesis (Schneider SA, Bulach, Switzerland) and two patients the barbed polyethylene-covered Gianturco stent (William Cook, Europe).

RESULTS

All patients had successful stent placement under intravenous sedation and fluoroscopic guidance with immediate relief of dysphagia and sealing of the perforation. Following the procedure all patients could eat either a normal diet or soft food and five patients were discharged within 3-4 days. None of the serious sequelae usually associated with oesophageal perforation were observed. Two patients required second overlapping stents to be inserted within 1 week because of minor migration of the initial endoprostheses. In one patient two stents were necessary because the carcinoma extended over 17 cm. Five patients died after stent insertion (mean survival time = 49 days, range 16-80; median survival time = 37 days, range 16-80) due to a general deterioration in their condition, although all could swallow normally until death. The remaining patient was well and tolerating a light diet at 1 month.

CONCLUSION

This technique is quick, safe and cost-effective and is now our preferred method of managing malignant oesophageal obstruction associated with perforation.

Agmatine recognizes alpha 2-adrenoceptor binding sites but neither activates nor inhibits alpha 2-adrenoceptors

It has been suggested that agmatine (decarboxylated arginine) is an endogenous clonidine-displacing substance (CDS) which recognizes alpha 2-adrenoceptor and non-adrenoceptor, imidazoline binding sites. We have examined the effect of agmatine at alpha 2-adrenoceptor binding sites and pre- and postjunctional alpha 2-adrenoceptors. Agmatine produced a concentration-dependent inhibition of 1 nmol/l 3H-clonidine binding to both rat (pKi-5.10 +/- 0.05) and bovine (pKi-4.77 +/- 0.38) cerebral cortex membranes. However, agmatine (0.1-100 microM) failed to activate pre-junctional alpha 2-adrenoceptors regulating transmitter release in the guinea-pig isolated ileum and rat isolated vas deferens, nor did it activate postjunctional alpha 2-adrenoceptors of the porcine isolated palmar lateral vein which mediate contraction or inhibition of forskolin-stimulated cyclic AMP formation. High concentrations of agmatine (10-30-fold the pKi at alpha 2-adrenoceptor binding sites) failed to influence alpha 2-adrenoceptor activation by either clonidine or UK-14304 (5-bromo-6-[2-imidazolin-2-ylamino]-quinoxaline bitartrate) in any of the peripheral preparations examined. Moreover, even in a preparation where an interaction with alpha 2-adrenoceptor binding sites on cell membranes can be demonstrated, the rat cerebral cortex, agmatine failed to inhibit forskolin-stimulated cyclic AMP in the intact tissue or affect the inhibition produced by the selective alpha 2-adrenoceptor agonist UK-14304. Agmatine was also devoid of agonist activity in two preparations, the rat isolated thoracic aorta and the rat isolated gastric fundus, in which CDS has been reported to produce non-adrenoceptor effects. Thus, we have confirmed that agmatine recognizes alpha 2-adrenoceptor binding sites and, therefore, is a CDS.(ABSTRACT TRUNCATED AT 250 WORDS)

Expression of pulmonary surfactant protein D in rat gastric mucosa

Gastric mucosa is protected from an acidic lumenal environment by an extracellular layer composed in part of phospholipids that are similar in composition to the phospholipids of lung surfactant. The function and metabolic processing of lung surfactant is regulated, in part, by surfactant specific proteins. We speculated that the gastric extracellular acid barrier might be regulated by such proteins. We demonstrate by RNA blot analysis, RT-PCR, and immunostaining and protein blot the synthesis of surfactant protein D (SP-D) in mucus-secreting cells of the gastric mucosa. SP-D protein and mRNA were not detected in the duodenum and the remainder of the gastrointestinal tract. We speculate that SP-D may participate in the regulation of secretion or assembly of the gastric acid barrier. Alternatively, SP-D may participate in gastric mucosal host defense.