Design of Potent and Proteolytically Stable Biaryl-Stapled GLP-1R/GIPR Peptide Dual Agonists

Recent clinical trials have revealed that the chimeric peptide hormones simultaneously activating glucagon-like peptide-1 receptor (GLP-1R) and glucose-dependent insulinotropic polypeptide receptor (GIPR) demonstrate superior efficacy in glycemic control and body weight reduction, better than those activating the GLP-1R alone. However, the linear peptide-based GLP-1R/GIPR dual agonists are susceptible to proteolytic cleavage by common digestive enzymes present in the gastrointestinal tract and thus not suitable for oral administration. Here, we report the design and synthesis of biaryl-stapled peptides, with and without fatty diacid attachment, that showed potent GLP-1R/GIPR dual agonist activities. Compared to a linear peptide dual agonist and semaglutide, the biaryl-stapled peptides displayed drastically improved proteolytic stability against the common digestive enzymes. Furthermore, two stapled peptides showed excellent efficacy in an oral glucose tolerance test in mice, owing to their potent receptor activity in vitro and good pharmacokinetics exposure upon subcutaneous injection. By exploring a more comprehensive set of biaryl staplers, we expect that this stapling method could facilitate the design of the stapled peptide-based dual agonists suitable for oral administration.

Early experience utilizing bivalirudin as anticoagulation in extracorporeal membrane oxygen in coronavirus disease 2019

Background

Extracorporeal membrane oxygenation (ECMO) is utilized as rescue therapy in patients diagnosed with coronavirus disease 2019 (COVID-19) with refractory respiratory or cardiogenic failure. Systemic anticoagulation with heparin remains the initial choice for thromboembolism prophylaxis in ECMO-treated patients. However, heparin carries the risk of severe complications, such as heparin-induced thrombocytopenia (HIT), and acquired antithrombin deficiency. Bivalirudin has been suggested as an alternative anticoagulant since it neither requires anti-thrombin III monitoring nor triggers HIT.

Purpose

There is very limited data on the utilization of bivalirudin in patients with COVID-19 treated with ECMO. We report the clinical safety and efficacy of using bivalirudin at our institution.

Methods

We retrospectively reviewed 17 patients diagnosed with COVID-19, who were treated with ECMO from 7/31/2020 to 12/20/2020. All patients received bivalirudin for thromboprophylaxis while on ECMO support.

Results

The mean age of our study cohort was forty-five years. Thirteen patients (76.4%) were of either Hispanic or African American descent. Of the seventeen patients, six (35.3%) patients developed deep venous thrombosis and one (5.9%) patient developed pulmonary embolism. Two (11.8%) patients developed a clotted circuit that required exchange. Fifteen (88.2%) patients had hemorrhage requiring transfusion with the gastrointestinal tract as the most common bleeding site. Nine (52.9%) patients developed thrombocytopenia. Six (35.3%) patients were discharged home or to a long-term acute care center; eleven (64.7%) patients died. The average length of stay was thirty-seven days.

Conclusion

In our small case series, the rates of complications and mortality remained high while using bivalirudin as anticoagulation of choice in patients diagnosed with COVID-19 and treated with ECMO. Further studies are needed to investigate the optimal anticoagulant in this population.

Funding Acknowledgement

Type of funding sources: None.

Unsymmetrical 1,1-Bisboryl Species: Valuable Building Blocks in Synthesis

Unsymmetrical 1,1-bis(boryl)alkanes and alkenes are organo-bismetallic equivalents, which are synthetically important because they allow for sequential selective transformations of C–B bonds. We reviewed the synthesis and chemical reactivity of 1,1-bis(boryl)alkanes and alkenes to provide information for the synthetic community. In the first part of this review, we disclose the synthesis and chemical reactivity of unsymmetrical 1,1-bisborylalkanes. In the second part, we describe the synthesis and chemical reactivity of unsymmetrical 1,1-bis(boryl)alkenes.

α-Borylalkyl radicals: their distinctive reactivity in modern organic synthesis

Organoborons are extremely important for synthetic organic chemistry; they can serve as advanced intermediates for a variety of transformations. Such a well-known transformation involves the loss of the boron moiety, creating alkyl radicals. Although these originally developed protocols for alkyl radical generation remain in active use today, in recent years their α-boryl carbon-centred radicals have been joined by a new array of radical generation strategies that offer a unique reactivity to forge a wider diversity of organoborons that often operate under mild and benign conditions. Herein, we will highlight the stability and reactivity of α-borylalkyl radicals and their remarkably recent advances in order to further utilise them for C-C and C-heteroatom bond formation. Their use for this purpose has been reported over the last decade in an attempt to guide the synthetic community. Various transition-metal and metal-free methods for their generation are presented, and more advanced photoredox approaches are discussed, mainly for the period of 2009-2019.

Enantioselective Synthesis of Cyclohexadienone Containing Spiroketals via DyKat Ketalization/oxa-Michael Addition Cascade

An oxidative dearomatization of phenol followed by a dynamic kinetic (DyKat) ketalization/oxa-Michael addition cascade using cinchona alkaloid-based chiral bifunctional amino-squaramide catalysts is reported. A broad array of sterically hindered [5,5]-spiroketals attached to a cyclohexadienone moiety in spiro-fashion is synthesized in an enantiopure form. Further, the methodology was optimized and extended to the corresponding benzannulated [5,5]-spiroketals attached to a cyclohexadienone moiety in spiro-fashion. In general, good yields and excellent diastereoselectivies and enantioselectivities (up to 20:1 dr and up to 99% ee) were obtained.

Nitrile-assisted oxidation over oxidative-annulation: Pd-catalyzed α,β-dehydrogenation of α-cinnamyl β-keto nitriles

A palladium-catalyzed oxidation reaction is disclosed where the nitrile functionality on the substrate simply changes the course of the reaction. Our previous finding showed that using the Pd(ii)-catalyst in the presence of benzoquinone as an oxidant, 2-cinnamyl-1,3-dicarbonyls provides functionalized furans via oxidative cyclization. When a nitrile group is replaced with one of the carbonyl functionalities of the same substrate, the oxidative cyclization was completely suppressed; instead, the oxidation at the α,β-position occurred to provide α,β,γ,δ-diene containing β-keto nitriles.

Catalyst-free Synthesis of 6-Hydroxy Indoles via the Condensation of Carboxymethyl Cyclohexadienones and Amines

An efficient catalyst-free synthesis of 6-hydroxy indoles from carboxymethyl cyclohexadienones and primary amines has been developed. The aza-Michael addition of the in situ formed enamine, generated through the condensation of carboxymethyl unit of the substrates with an external amine, to cyclohexadienone moiety followed by rearomatization reaction to provide such indoles. Anilines, aliphatic amines, α-chiral aliphatic amines, or even ammonia were used as amine counterpart. Some of the cyclohexadienones gave 6-amino indoles instead of 6-hydroxy indoles using the Re₂O₇ catalyst. Various post methodological transformations were performed to explore the synthetic utility of the synthesized hydroxy indoles.

Seasonal characteristics of water-soluble inorganic ions and carbonaceous aerosols in total suspended particulate matter at a rural semi-arid site, Kadapa (India)

To better understand the sources as well as characterization of regional aerosols at a rural semi-arid region Kadapa (India), size-resolved composition of atmospheric particulate matter (PM) mass concentrations was sampled and analysed. This was carried out by using the Anderson low-pressure impactor for a period of 2 years during March 2013-February 2015. Also, the variations of organic carbon (OC), elemental carbon (EC) and water-soluble inorganic ion components (WSICs) present in total suspended particulate matter (TSPM) were studied over the measurement site. From the statistical analysis, the PM mass concentration showed a higher abundance of coarse mode particles than the fine mode during pre-monsoon season. In contrast, fine mode particles in the PM concentration showed dominance over coarse mode particle contribution during the winter. During the post-monsoon season, the percentage contributions of coarse and fine fractions were equal, whereas during the monsoon, coarse mode fraction was approximately 26 % higher than the fine mode. This distinct feature in the case of fine mode particles during the studied period is mainly attributed to large-scale anthropogenic activities and regional prevailing meteorological conditions. Further, the potential sources of PM have been identified qualitatively by using the ratios of certain ions. A high sulphate (SO₄) concentration at the measurement site was observed during the studied period which is caused by the nearby/surrounding mining activity. Carbon fractions (OC and EC) were also analysed from the TSPM, and the results indicated (OC/EC ratio of ~4.2) the formation of a secondary organic aerosol. At last, the cluster backward trajectory analyses were also performed at Kadapa for different seasons to reveal the origin of sources from long-range transport during the study period.

Columnar-integrated aerosol optical properties and classification of different aerosol types over the semi-arid region, Anantapur, Andhra Pradesh

This study presents a characterization of aerosol columnar properties measured at a semi-arid station Anantapur in the southern part of India during the period from October 2012 to September 2013. Aerosol optical depth (AOD) and Angstrom exponent (α) have been retrieved from Microtops II Sunphotometer over the observation site. The results show that a pronounced spectral and monthly variability in the optical properties of aerosols is mainly due to anthropogenic sources. The results show that the spectral curvature can effectively be used as a tool for aerosol type discrimination, since the fine-mode aerosols exhibit negative curvature, while the coarse-mode particles are positive. The classification of aerosols is also proposed by using the values of AOD at 500 nm and Angstrom exponent values (α(380-870)) by applying threshold values obtained from the frequency distribution of AOD. The results of the analysis were identified by four individual components (anthropogenic/biomass burning, coarse/dust, coarse/marine, clean continental) of different origin and compositions. The most frequent situations observed over the site are that due to the anthropogenic/biomass burning situations which account for about 45.37%, followed by coarse/dust (43.64%), clean continental (7.2%) and coarse/marine (3.82%) during summer. The identification of the aerosol source type and the modification processes are analyzed by using the Gobbi et al. (2007) classification scheme based on the measured scattering properties (α, dα) derived from the Microtops II Sunphotometer.

Inferring wavelength dependence of AOD and Ångström exponent over a sub-tropical station in South Africa using AERONET data: influence of meteorology, long-range transport and curvature effect

Aerosol optical properties over a southern sub-tropical site Skukuza, South Africa were studied to determine the variability of the aerosol characteristics using CIMEL Sunphotometer data as part of the AErosol RObotic NETwork (AERONET) from December 2005 to November 2006. Aerosol optical depth (AOD), Ångström exponent (α), and columnar water vapor (CWV) data were collected, analyzed, and compiled. Participating in this network provided a unique opportunity for understanding the sources of aerosols affecting the atmosphere of South Africa (SA) and the regional radiation budget. The meteorological patterns significantly (p<0.05) influenced the amount and size distribution of the aerosols. Results showed that seasonal variation of AOD at 500 nm (AOD500) over the observation site were characterized by low values (0.10-0.13) in autumn, moderate values (0.14-0.16) in summer and winter seasons, and high to very high values (0.18-0.40) during the spring, with an overall mean value of 0.18±0.12. Ångström exponent α(440-870), varied from 0.5 to 2.89, with significant (p<0.0001) seasonal variability. CWV showed a strong annual cycle with maximum values in the summer and autumn seasons. The relationship between AOD, Ångström exponent (α), and CWV showed a strong dependence (p<0.0001) of α on AOD and CWV, while there was no significant correlation between AOD and CWV. Investigation of the adequacy of the simple use of the spectral AOD and Ångström exponent data was used in deriving the curvature (a2) showed to obtain information for determining the aerosol-particle size. The negative a2 values are characterized by aerosol-size dominated by fine-mode (0.1-1 μm), while the positive curvatures indicate abundance of coarse particles (>1 μm). Trajectory cluster analyses revealed that the air masses during the autumn and winter seasons have longer advection pathways, passing over the ocean and continent. This is reflected in the aerosol properties that are derived from the ocean, desert, and anthropogenic activities that include biomass burning and industrial pollution.

Screening for maternal coeliac disease as a potential risk factor for orofacial clefts--a pilot study

There is increasing evidence that dietary folic acid deficiency in utero may increase the risk of developing the 'cleft lip with or without cleft palate' (CL±P) variant of orofacial cleft. Coeliac disease is a common cause of folic acid malabsorption, and in the majority of cases remains undiagnosed. This pilot study assessed the seroprevalence of undiagnosed coeliac disease in a cohort of mothers of infants with CL±P in the Hyderabad area of India. The seroprevalence of coeliac disease of 1.15% (95% confidence interval 0.37-2.66%) was little different from the expected figure based on published population studies, making a clinically significant association unlikely.

In-vitro and in-vivo anti-inflammatory activity of Andrographis serpyllifolia (Rottl. Ex Vahl.) Wt

The study was aimed to evaluate the analgesic and anti-inflammatory activity (by both in-vitro and in-vivo) of both chloroform and methanol root extracts of Andrographis serpyllifolia (Rottl. Ex Vahl.) Wt. Methods used for the studies were In-vitro 5-Lipoxygenase inhibition assay and In-vivo measurement of rat paw edema and ear edema in rats, acetic acid induced writhing response and hot plate method in albino mice. Chloroform and methanolic extracts of A. serpyllifolia root have shown moderate potency in inhibiting 5-LOX and shown significant anti-inflammatory activity. Despite the IC50 values are little higher, anti-inflammatory efficacy of these extracts possibly due to other mechanisms apart of 5-LOX inhibition. However, In-vivo anti-inflammatory studies revealed that A. serpyllifolia methanolic extract has shown higher degree of efficacy when compared to the chloroform extract. In terms of analgesic activity in writhing test, methanolic extract has shown more efficacy than chloroform extract. Hence, it is important to isolate the active principles for further testing the anti-inflammatory efficacy.DOI: http://dx.doi.org/10.3329/icpj.v1i8.11250 International Current Pharmaceutical Journal 2012, 1(8): 199-204 

Size segregated mass concentration and size distribution of near surface aerosols over a tropical Indian semi-arid station, Anantapur: Impact of long range transport

Regular measurements of size segregated as well as total mass concentration and size distribution of near surface composite aerosols, made using a ten-channel Quartz Crystal Microbalance (QCM) cascade impactor during the period of September 2007-May 2008 are used to study the aerosol characteristics in association with the synoptic meteorology. The total mass concentration varied from 59.70+/-1.48 to 41.40+/-1.72 microg m(-3), out of which accumulation mode dominated by approximately 50%. On a synoptic scale, aerosol mass concentration in the accumulation (submicron) mode gradually increased from an average low value of approximately 26.92+/-1.53 microg m(-3) during the post monsoon season (September-November) to approximately 34.95+/-1.32 microg m(-3) during winter (December-February) and reaching a peak value of approximately 43.56+/-1.42 microg m(-3) during the summer season (March-May). On the contrary, mass concentration of aerosols in the coarse (supermicron) mode increased from approximately 9.23+/-1.25 microg m(-3)during post monsoon season to reach a comparatively high value of approximately 25.89+/-1.95 microg m(-3) during dry winter months and a low value of approximately 8.07+/-0.76 microg m(-3) during the summer season. Effective radius, a parameter important in determining optical (scattering) properties of aerosol size distribution, varied between 0.104+/-0.08 microm and 0.167+/-0.06 microm with a mean value of 0.143+/-0.01 microm. The fine mode is highly reduced during the post monsoon period and the large and coarse modes continue to remain high (replenished) so that their relative dominance increases. It can be seen that among the two parameters measured, correlation of total mass concentration with air temperature is positive (R(2)=0.82) compared with relative humidity (RH) (R(2)=0.75).

Temporal and spectral characteristics of aerosol optical depths in a semi-arid region of southern India

The spectral and temporal variations of aerosol optical depths (AOD) observed over Anantapur (a semi-arid region) located in the Southern part of India are investigated by analyzing the data obtained from a Multiwavelength Solar Radiometer (MWR) during January 2005-December 2006 (a total of 404 clear-sky observations) using the Langley technique. In this paper, we highlighted the studies on monthly, seasonal and spectral variations of aerosol optical depth and their implications. The results showed seasonal variation with higher values during pre-monsoon (March-May) and lower in the monsoon (June-November) season at all wavelengths. The pre-monsoon increase is found to be due to the high wind speed producing larger amounts of wind-driven dust particles. The post-monsoon (December-February) AOD values decrease more at higher wavelengths, indicating a general reduction in the number of bigger particles. Also during the post-monsoon, direction of winds in association with high or low pressure weather systems and the air brings more aerosol content to the region which is surrounded by a number of cement plants, lime kilns, slab polishing and brick making units. The quantity of AOD values in pre-monsoon is higher (low during post-monsoon) for wavelength, such as shortwave infrared (SWIR) or near infrared (NIR), which shows that coarse particles contribute more compare with the sub-micron particles. The composite aerosols near the surface follow suit with the share of the accumulation mode to the total mass concentration decreasing from approximately 70% to 30% from post-monsoon to pre-monsoon. Coarse mode particle loading observed to be high during pre-monsoon and accumulation mode particles observed to be high during post-monsoon. The backward trajectories at three representative altitudes with source point at the observing site indicate a possible transport from the outflow regions into Bay of Bengal, southern peninsular India and Arabian Sea. The temporal variations of AOD, Angstrom wavelength exponent and precipitable water content over Anantapur have also been compared with those reported from selected locations in India.

Spectroscopic properties of Dy(3+) ions in NaF-B(2)O(3)-Al(2)O(3) glasses

This paper reports the optical properties of Dy(3+) in sodium fluoroborate glasses of the type XNaF.(89-X)B(2)O(3).10 Al(2)O(3).1Dy(2)O(3) (where X=8, 12, 16, 20 and 24). Judd-Ofelt intensity parameters (Omega(2), Omega(4), Omega(6)) are derived from the absorption spectra. The Judd-Ofelt theory has been applied to interpret the local environment of Dy(3+) ions and bond covalency of RE-O bond. These parameters have been used to calculate radiative transition probabilities (A(rad)), lifetimes (tau(R)) and branching ratios (beta(R)) for the excited level (4)F(9/2). The predicted values of tau(R) are compared with the measured values for (4)F(9/2) level for five glass compositions (Glass (A-E)). The stimulated emission cross-section sigma(lambda(P)) are also evaluated for the (4)F(9/2)-->(6)H(J) (J=11/2, 13/2, and 15/2) transitions.

Postoperative infection of laparoscopic surgery wound due to Mycobacterium chelonae

We report a case of postoperative wound infection due to Mycobacterium chelonae. A 35-year-old woman presented with multiple erythematous nodules, plaques and discharging sinuses over the abdomen, 45 days after she had undergone laparoscopic ovarian cystectomy. The seropurulent discharge from the wound showed acid-fast bacilli on Ziehl- Neelsen stain and culture yielded Mycobacterium chelonae. The patient responded to clarithromycin and doxycycline. The source of infection was probably contaminated water or disinfectant solution used for sterilization of laparoscopic instruments.

Study of genital lesions

A total of one hundred patients (75 males and 25 females) age ranged from 17-65 years with genital lesions attending the STD clinic of Bowring and LC Hospitals Bangalore constituted the study group. Based on clinical features, the study groups were classified as syphilis (39), chancroid (30), herpes genitalis (13), condylomato lato (9), LGV (7t condylomata acuminata (5), genital scabies (3), granuloma inguinole (2) and genital candidiasis (1). In 68% microbiological findings confirmed the clinical diagnosis. Of the 100 cases 13% and 2% were positive for HIV antibodies and HbsAg respectively.

Porous silicon based potentiometric triglyceride biosensor

A novel method for estimating triglycerides is reported. Porous silicon, prepared from p-type (100) crystalline silicon was thermally oxidized and used to immobilise lipase, an enzyme, which hydrolyses triglycerides resulting in the formation of fatty acids. This causes a change in the pH of the solution. Enzyme solution-oxidized porous silicon-crystalline silicon structure was used to detect changes in pH during the hydrolysis of tributyrin as a shift in the capacitance-voltage (C-V) characteristics. Detailed calibration of the sensor is included.

Epidemiology of symptomatic human rotaviruses in Bangalore and Mysore, India, from 1988 to 1994 as determined by electropherotype, subgroup and serotype analysis

Epidemiology of symptomatic rotaviruses from Bangalore and Mysore in Southern India was investigated. While serotype G3 predominated throughout the 7-year study period from 1988 to 1994 in Bangalore, serotype G1 was more predominant than serotype G3 in Mysore during 1993 and 1994. Serotype G2 strains were either not detected or infrequently observed in both the cities. However, several strains with subgroup I and 'short' RNA pattern that exhibited high reactivity with typing MAbs specific for serotype 2 as well as other serotypes were detected throughout the period. Among the nonserotypeable strains from both cities, several exhibited dual subgroup (SGI + II) or subgroup I specificity and 'long' RNA pattern indicating their probable animal origin. Notably, a gradual, yet highly significant reduction in rotavirus gastroenteritis, from 45.3% in 1988 to 1.8% during 1994, was observed in Bangalore in stark contrast to the consistently high (about 34%) incidence of asymptomatic infections among neonates by I321-like G10P11 type strains during the same period. Moreover, I321-like asymptomatic strains were not detected in children with diarrhea.

Decreased adhesiveness and altered cellular distribution of fibronectin in fibroblasts from schizophrenic patients

Relative to those from normal subjects, cultured skin fibroblasts from schizophrenic patients have been found to show abnormal growth characteristics and morphology. This study compared skin fibroblasts from 10 drug-free schizophrenic patients and 10 normal control subjects on cell adhesiveness to the substratum. Relative to fibroblasts from normal controls, those from patients showed significantly decreased cell adhesiveness, with no overlap in distribution between the groups. Since fibronectin, a major cell surface molecule, is known to be involved in the fibroblast adhesion to substratum, its extracellular and intracellular distribution was determined by immunocytochemical analysis. Both extracellular and intracellular levels of fibronectin were significantly lower, and the distribution was altered in fibroblasts from the patients.

Exclusive asymptomatic neonatal infections by human rotavirus strains having subgroup I specificity and "long" RNA electropherotype

A large number of stool specimens, of healthy newborn infants, collected from various hospitals and clinics in Bangalore City, India, have been examined for the presence of asymptomatic rotaviral excretion. Out of 370 samples analysed during a three year period from 1988 to 1991, 133 specimens (36%) were positive for rotavirus RNA. All these asymptomatic neonatal strains, without exception, showed "long" RNA pattern, but subgroup I specificity. Serotype analysis by ELISA or by hybridization with serotype-specific probes indicated that these strains probably represent a new serotype in newborn children. We find an exclusive association of human rotaviruses having "long" RNA pattern and subgroup I specificity with asymptomatic neonatal infections in contrast to the earlier observations of association of such unusual strains with acute gastroenteritis in young children.

Multifocal Langerhans cell histiocytosis of the jaws: a case report

Langerhans cell histiocytosis is an uncommon disease that includes a spectrum of disorders in which there is an abnormal proliferation of Langerhans cells. This article describes a case of a benign form of multifocal Langerhans cell histiocytosis of the maxilla and mandible. The patient was followed for a period of 2 1/2 years, during which time there was spontaneous remission of some of the lesions.

The high rate of prevalence of CT-detected basal ganglia calcification in neuropsychiatric (CNS) brucellosis

Of 65 cases presenting with neuropsychiatric manifestations of brucellosis (CNS-brucellosis), 9(13.8%) had CT-detected basal ganglia calcification (BGC). Of these, 5 had meningitis and 4 had psychiatric manifestations as presenting features. The diagnosis of brucellosis was made by the finding of consistent history and physical findings and the presence of significantly elevated antibody titres and/or positive culture in the blood and/or CSF. In all the cases, BGC was in the form of punctate hyperdense non-enhancing shadows with average density 44.5-58.4 and maximum density 49-64HU. The calcification was unilateral in 3 cases, bilateral and symmetrical in 4 and bilateral but asymmetrical in 2. None of the cases had other predisposing conditions to BGC and in one of the cases did specific anti-brucella treatment effect a detectable change in the BGC. The finding of CT-detected BGC in patients coming from areas endemic for brucellosis should alert physicians to the possibility of underlying brucellar infection.

The endoscopic variety of duodenal villous adenoma - an experience with ten cases

Ten cases of villous adenoma of the duodenum among 8,754 endoscopic examinations of the upper gastrointestinal tract were found over a nine year period. The varied clinical manifestations included gastrointestinal bleeding in five cases, partial duodenal obstruction in four, and jaundice with common bile duct obstruction in two. In only two cases did radiological examination indicate the diagnosis of villous adenoma of the duodenum in all ten cases preoperatively but was negative for carcinoma in one. Due to improved diagnostic techniques villous adenoma of the duodenum is being diagnosed at an early stage, and with appropriate surgical treatment the survival rate for this group of patients should improve.

Duodenal polyps: diagnosis and management

Forty-five polyps were encountered at duodenoscopy between 1973 and 1978. Upper gastrointestinal x-rays were helpful in 25 patients, 13 of whom had duodenal polyps and 12 duodenal deformity or mass lesions. Polyps in 23 patients were larger than 1 cm in size. Biopsies were done in 38 patients; in 19 there was only normal duodenal mucosa or chronic inflammation. Eight adenomatous polyps, six villous adenomas, two Brunner's gland hyperplasia, two lipomas, and one carcinoid tumor were found. Surgery was performed in eight patients and endoscopic polypectomy in four. We conclude that 1) small duodenal polyps are frequently missed on upper gastrointestinal x-rays, but these are submucosal polyps of little significance; 2) in general, polyps cannot be differentiated endoscopically into tissue categories, but villous adenomas show some characteristic features which allow a dependable endoscopic diagnosis; 3) a villous adenoma warrants excision because of the high incidence of malignancy; and 4) pedunculated duodenal polyps can be removed safely with endoscopic snare excision.