Ascending thoracic aortic aneurysm size at presentation and growth by diameter

AIM

To investigate the hypothesis that lung cancer screening allows for earlier identification of ascending thoracic aortic aneurysms (aTAAs) and that growth rates for aTAAs are greatest at larger sizes.

MATERIALS AND METHODS

This single referral centre retrospective study manually gathered computed tomography (CT) data from 732 patients presenting from July 2002 to August 2022. Five hundred and seventeen patients with aTAA >39 mm were identified to compare presenting diameter by year of presentation. Four hundred and thirty-two patients had CT examinations >3 months apart, allowing for growth analysis. Patients were separated by initial examination date (before or after 12/31/2013) for presenting size comparison. Patients were then divided into five groups based on aTAA diameter for growth rate analysis.

RESULTS

At identification, patients had a median aTAA diameter of 44 mm (IQR 41-47 mm). Patients with aTAAs identified prior to December 2013 (n=129) had an average aTAA diameter 1.7 mm larger than those identified later (n=388; p=0.003). The growth analysis showed an average growth rate of 0.1 mm/year (p<0.001) across the entire cohort. Patients with an aTAA diameter of ≥55 mm (n=12) grew the fastest at 1.9 mm/year (p<0.001). In the <40 mm group (n=43), the aTAAs expanded at 0.2 mm/year, faster than the 0.1 mm/year of the slowest expanding 45-49 mm group (n=130; p=0.04).

CONCLUSION

aTAA size at discovery was larger before lung cancer screening guidelines took effect in December 2013. The largest aTAAs expanded fastest, but growth rates were slowest in the medium-sized 45-49 mm diameter group.

Use of lumen-apposing metal stents in treating gastrojejunal anastomotic strictures in bariatric patients

BACKGROUND

Gastrojejunal strictures (GJS) are rare but significant adverse events following Roux-en-Y Gastric Bypass, with limited options for effective non-operative interventions. Lumen-apposing metal stents (LAMS) represent a new therapy for treatment of intestinal strictures, but the effectiveness in treating GJS is unknown. This study aims to evaluate the safety and effectiveness of LAMS in GJS.

METHODS

This is a prospective, observational study of patients with prior Roux-en-Y Gastric bypass who underwent LAMS placement for GJS. The primary outcome of interest is resolution of GJS following LAMS removal defined by toleration of bariatric diet after LAMS removal. Secondary outcomes include need for additional procedures, LAMS-related adverse events, and need for revisional surgery.

RESULTS

Twenty patients were enrolled. The cohort was 85% female with median age of 43. 65% had marginal ulcers associated with the GJS. Presenting symptoms included nausea and vomiting (50% of patients), dysphagia (50%), epigastric pain (20%), and failure to thrive (10%). Diameter of LAMS placed were 15 mm in 15 patients, 20 mm in 3 patients, and 10 mm in 2 patients. LAMS were placed for a median of 58 days (IQR 56-70). Twelve patients (60%) achieved resolution of GJS after LAMS removal. Of the eight patients without GJS resolution or with recurrence, seven (35%) required repeat placement of LAMS. One patient was lost to follow up. One perforation and two migrations occurred. Four patients required revisional surgery after LAMS removal.

CONCLUSION

LAMS placement is well-tolerated and effective with most patients achieving short-term symptom resolution and with few reported complications. While stricture resolution occurred in over half the patients, nearly 1/4th of patients required revisional surgery. More data is needed to predict who would benefit from LAMS versus surgical intervention.

Increased mortality in patients with alcohol-induced pancreatitis during the COVID-19 pandemic

Background

COVID-19 pandemic affected millions of people worldwide. Alcohol consumption increased during the pandemic, leading to rising numbers of cases of alcohol-related pancreatitis. We aimed to assess the mortality of alcohol-induced pancreatitis during the COVID-19 pandemic in the United States.

Methods

We analyzed the National Vital Statistical System's (NVSS) provisional multiple causes of death data, provided by the Centers for Disease Control and Prevention, to assess the mortality of alcohol-induced pancreatitis during the pandemic. Patients with alcohol-induced pancreatitis as a cause of death were analyzed between 2018 and 2021. Patient demographics such as age, sex, ethnicity, and location were studied.

Results

During 2018-2021, there were 2547 deaths from alcohol-induced pancreatitis. The total cases and age-adjusted rates of alcohol-induced pancreatitis per 100,000 were similar in 2018 (n=515) and 2019 (n=501) (crude rate=0.1). The number increased to 747 in 2020 and 784 in 2021 (crude rate=0.2). A statistically significant increase in mortality rates was noted in all age groups except 75-84. An increase in mortality in both males and females was noted (48% increase and 64% increase, respectively, P<0.001). The number of deaths increased in both Hispanics (59%, P<0.001) and non-Hispanics (48%, P<0.001).

Conclusions

Our analysis demonstrated a substantial increase in the mortality of patients with alcohol-induced pancreatitis during the first 2 years of the COVID-19 pandemic. The increase in alcohol consumption and the burden on mental health caused massive collateral damage to society. Urgent public health interventions are needed at state and national levels to prevent further rise in cases.

Enteral Stents for Malignant Gastric Outlet Obstruction: Low Reintervention Rates for Obstruction due to Pancreatic Adenocarcinoma Versus Other Etiologies

BACKGROUND AND AIM

Enteral stents (ES) have emerged as first-line therapy for the treatment of malignant gastric outlet obstruction (GOO). Stent occlusion arising from tissue ingrowth may require endoscopic or surgical reintervention. The objective of this study was to compare rates of reintervention following palliative ES for patients with GOO due to pancreatic adenocarcinoma (PDAC) versus other malignant etiologies.

METHODS

Patients who had undergone ES for palliation of malignant GOO between 2009 and 2018 were retrospectively identified and demographic, clinical, and procedural data were collected. Primary outcome was procedural reintervention for recurrent symptomatic GOO following ES placement.

RESULTS

Forty-three patients were included in the study cohort. 62.8% (27/43) of patients had PDAC while 37.2% (16/43) of patients had other malignant etiologies. 11.6% (5/43) of patients were alive at follow-up. Thirty-day and 90-day mortality rates were 22.8% and 70.7% for PDAC and 25% and 56.3% for other malignant etiologies, respectively. Seven patients required reintervention for symptomatic GOO: 14.3% (1/7) had PDAC and 85.7% (6/7) had GOO due to other malignancy (P < .01). Ninety-six percent (26/27) of patients with PDAC required no further intervention for GOO prior to death or end of follow-up. On multivariate analysis, patients with PDAC were significantly less likely to require reintervention than patients with other malignant etiologies (OR 0.064, 95% CI 0.01-0.60).

CONCLUSION

ES offer durable symptom palliation without requirement for reintervention for the overwhelming majority of patients with malignant GOO due to PDAC. Reintervention rates are higher following ES placement for GOO due to other malignant etiologies and future study may be needed to define the optimal palliative intervention for this group of patients.

Endoscopic plastic stent therapy for bile leaks following total vs subtotal cholecystectomy

Background and study aims  Plastic biliary stents are standard therapy for treatment of post-cholecystectomy bile leaks. An increasing proportion of patients now undergo subtotal cholecystectomy and are at perceived risk for high-grade bile leak. Data are limited regarding the optimal endoscopic therapy following subtotal cholecystectomy. The aim of this study was to compare outcomes of endoscopic plastic stent therapy for treatment of bile leak following total vs subtotal cholecystectomy. Patients and methods  A retrospective cohort of patients with bile leak following cholecystectomy and treated with biliary stent was identified from an institutional database. Primary outcome was defined as cholangiographic resolution of leak at follow-up endoscopic retrograde cholangiopancreatography (ERCP). Results  Sixty-one subjects met study inclusion criteria, 27 following total cholecystectomy and 34 following subtotal cholecystectomy. A single plastic biliary stent was placed in 87 % of subjects (53/61), while a fully covered self-expanding metal stent (FCSEMS) was placed in 13 % (8/61). Leak resolution was evident at first follow-up ERCP in 96 % of subjects (26/27) who had undergone total cholecystectomy and 91 % of subjects (31/34) who had undergone subtotal cholecystectomy ( P  = 0.25). Among subjects who had received a plastic stent at index ERCP, leak resolution was evident at first follow-up ERCP in 96 % (23/24) of those who had undergone total cholecystectomy and 90 % (26/29) of those who had undergone subtotal cholecystectomy ( P  = 0.62). Conclusions  High rates of leak resolution can be achieved with placement of a single plastic biliary stent for treatment of post-cholecystectomy bile leaks, including after subtotal cholecystectomy.

Preferencias de los granívoros con respecto al tamaño y la calidad de las bellotas en un bosque de Quercus en la zona centroseptentrional de México

Acorns of the species of the genus Quercus are highly appreciated by a diverse group of animals. It remains unclear whether the choice to move an acorn is related to the intrinsic characteristics of the fruit. In this work, we aimed to determine whether the size and quality of acorns (healthy or damaged) influenced their removal. We found that Q. affinis was the species with the largest acorns but the lowest removal rate, and Q. eduardii was the species with the smallest acorns but highest removal rates. Two groups of vertebrates carried out this removal, and this activity occurred at two clearly separate times. Jays Aphelocoma spp. carried out their activity during the day, and rodents Peromyscus spp. removed acorns at night. Size and quality only had a significant influence on the removal of Q. affinis. Our results suggest that absence of large animals could put the establishment of species with large acorns (such as Q. affinis) at risk.

The face of postural tachycardia syndrome - insights from a large cross-sectional online community-based survey

BACKGROUND

Patients with postural tachycardia syndrome (POTS) experience chronic symptoms of orthostatic intolerance. There are minimal data detailing the demographics, clinical features and clinical course of this condition. This online, community-based survey highlights patients' experience with POTS. It consists of the largest sample of POTS patients reported to date.

OBJECTIVES

To describe the demographics, past medical history, medications, treatments and diagnostic journey for patients living with POTS.

METHODS

Postural tachycardia syndrome patients completed an online, community-based, cross-sectional survey. Participants were excluded if they had not received a diagnosis of POTS from a physician. The questions focused on the patient experience and journey, rather than physiological responses.

RESULTS

The final analysis included 4835 participants. POTS predominantly affects white (93%) females (94%) of childbearing age, with approximately half developing symptoms in adolescence (mode 14 years). POTS is a chronic multisystem disorder involving a broad array of symptoms, with many patients diagnosed with comorbidities in addition to POTS. POTS patients often experience lengthy delays [median (interquartile range) 24 (6-72) months] and misdiagnosis, but the diagnostic delay is improving. POTS patients can present with a myriad of symptoms most commonly including lightheadedness (99%), tachycardia (97%), presyncope (94%), headache (94%) and difficulty concentrating (94%).

CONCLUSIONS

These data provide important insights into the background, clinical features and diagnostic journey of patients suffering from POTS. These data should serve as an essential step for moving forward with future studies aimed at early and accurate diagnoses of these patients leading to appropriate treatments for their symptoms.

Histologic Analysis of Endoscopic Ultrasound-Guided Through the Needle Microforceps Biopsies Accurately Identifies Mucinous Pancreas Cysts

BACKGROUND & AIMS

It is a challenge to accurately assess pancreatic cystic lesions (PCLs) and determine their risk. We compared the yield of tissue acquired with endoscopic ultrasound (EUS)-guided microforceps (through the needle tissue biopsy [TTNB]) with that of samples collected by EUS-guided fine-needle-aspiration (EUS-FNA), and the accuracy of analyses of each sample type in the diagnosis of mucinous PCLs.

METHODS

We performed a prospective open-label study of 114 consecutive adults (56.1% women; mean age, 64.2 y) undergoing EUS-FNA evaluation of PCLs (mean size, 35 mm) at 7 centers, from June 20, 2016, through August 31, 2018. Samples were collected from each cyst by FNA and microforceps; samples collected by FNA were analyzed by cytology and samples collected by TTNB were analyzed by histology. Acquisition yield was defined as the percentage of specimens collected that were adequate for cytologic or histologic analysis. Diagnoses of mucinous cysts were made based on identification of pancreatic mucinous epithelium by cytology analysis of FNA samples or histologic analysis of TTNB samples. Surgical specimens were used as the reference standard when available.

RESULTS

The EUS-guided microforceps were successfully inserted into 97.4% (111 of 114) of PCLs. Tissue acquisition yield was significantly higher with TTNB (95 of 114; 83.3%) than FNA (43 of 114; 37.7%) (P < .001). Sixty-one PCLs were determined to be mucinous based on TTNB analysis (53.5%) vs 11 with FNA analysis (9.6%) (P < .001). Among PCLs categorized as equivocal, based on the level of carcinoembryonic antigen, TTNB analysis found 50% (41 of 82) to be mucinous and FNA analysis found 8.5% (7 of 82) to be mucinous (P < .001). Findings from analyses of samples collected by TTNB were 100% concordant with findings from histologic analysis of surgical specimens (14 of 14), whereas only 3 of 14 findings from analysis of samples collected by FNA were in agreement with findings from surgical specimens (21.4%) (P < .001). Four of 5 mucinous PCLs with advanced neoplasia (80%) were detected with TTNB compared with none with FNA (P = .04). Self-limited intracystic bleeding occurred in 7 patients (6.1%), and acute pancreatitis in 6 patients (5.3%).

CONCLUSIONS

In a multicenter prospective study of patients undergoing EUS-FNA for evaluation of PCLs, we found TTNB collection of tissues for histologic analysis to be safe and feasible, with an acquisition yield of 83.3%. Histologic analysis of samples collected by TTNB identified a larger proportion of mucinous PCLs compared with cytologic analysis of samples collected by FNA-even among samples categorized as equivocal, based on the level of carcinoembryonic antigen. More samples collected by TTNB than FNA were found to have advanced neoplasia. Clinicaltrials.gov no: NCT02979509.

Mucinous cystic neoplasm diagnosed by EUS-guided microforceps biopsy

Background and study aims  Mucinous cystic neoplasms (MCNs) of the pancreas have malignant potential. Current methods for diagnosing MCNs are inadequate. The aim of this case series is to present a novel method for establishing the diagnosis of MCNs. Clinical information from three patients seen at our institution was collected for a case series presentation. Patients were selected retrospectively based on diagnostic results. Three patients were diagnosed with MCNs based on histopathology obtained via microforceps biopsy. Evolving tissue acquisition techniques, such as microforceps intracystic biopsy, have improved the diagnostic yield of endoscopic ultrasound (EUS).

Competence in Endoscopic Ultrasound and Endoscopic Retrograde Cholangiopancreatography, From Training Through Independent Practice

BACKGROUND & AIMS

It is unclear whether participation in competency-based fellowship programs for endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) results in high-quality care in independent practice. We measured quality indicator (QI) adherence during the first year of independent practice among physicians who completed endoscopic training with a systematic assessment of competence.

METHODS

We performed a prospective multicenter cohort study of invited participants from 62 training programs. In phase 1, 24 advanced endoscopy trainees (AETs), from 20 programs, were assessed using a validated competence assessment tool. We used a comprehensive data collection and reporting system to create learning curves using cumulative sum analysis that were shared with AETs and trainers quarterly. In phase 2, participating AETs entered data into a database pertaining to every EUS and ERCP examination during their first year of independent practice, anchored by key QIs.

RESULTS

By the end of training, most AETs had achieved overall technical competence (EUS 91.7%, ERCP 73.9%) and cognitive competence (EUS 91.7%, ERCP 94.1%). In phase 2 of the study, 22 AETs (91.6%) participated and completed a median of 136 EUS examinations per AET and 116 ERCP examinations per AET. Most AETs met the performance thresholds for QIs in EUS (including 94.4% diagnostic rate of adequate samples and 83.8% diagnostic yield of malignancy in pancreatic masses) and ERCP (94.9% overall cannulation rate).

CONCLUSIONS

In this prospective multicenter study, we found that although competence cannot be confirmed for all AETs at the end of training, most meet QI thresholds for EUS and ERCP at the end of their first year of independent practice. This finding affirms the effectiveness of training programs. Clinicaltrials.gov ID NCT02509416.

Oral bisphosphonate prescription and non-adherence at 12 months in patients with hip fractures treated in an acute geriatric unit

A poorer functional status at the time of fracture is a predictor of non-adherence to oral bisphosphonates initiated after a hip fracture, and suggests further opportunities for optimization of secondary fracture prevention in this high-risk population.

INTRODUCTION

Low adherence to treatment is a problem in post-fracture secondary prevention. We aimed to analyze the prognostic factors (related and predictive) associated with non-adherence to oral bisphosphonate prescription for hip fracture due to bone fragility (HFBF) 12 months after discharge from an acute geriatric unit.

METHODS

Prospective study of bivariate data analyzing related and multivariate factors predicting non-adherence of oral bisphosphonates at 12 months after treatment for HFBF. The statistical study was performed with SPSS 19.0.0.

RESULTS

We attended 368 patients with HFBF. At discharge, oral bisphosphonates were prescribed to 226 (61.42%) patients. At 12 months, we followed up 160 (70.7%) patients, 104 (65%) of whom had non-adherence to oral bisphosphonates. Bivariate analysis (adherent vs. non-adherent): age (83.79 ± 5.82 vs. 85.78 ± 5.80, p = .029); Lawton and Brody Index (4.29 ± 3.40 vs. 2.67 ± 3.31, p = .004); baseline Barthel Index (BI) (85.89 ± 21.99 vs. 74.18 ± 26.70) (p = .004); BI at admission (18.84 ± 10.00 vs. 14.47 ± 11.71, p = .004); BI at discharge (34.20 ± 15.40 vs. 27.45 ± 16.71, p = .011); baseline Functional Ambulation Classification (5.66 ± 0.98 vs. 5.43 ± 0.99, p = .025). Multivariate analysis: BI 0.980 (0.965-0.995, p = .007). Discriminatory capacity of the AUC model (± 95% CI): 0.634 (0.545-0.722).

CONCLUSIONS

At 12 months, there was low adherence to treatment with oral bisphosphonates in our model. A lower BI prior to treatment is a predictive factor for non-adherence treatment with oral bisphosphonate.

Migraine in the Andes and Headache at Sea Level

In Cerro de Pasco (CP), Peru (altitude 4338 m) 24% of men have migraine with aura. We studied 30 men. Twenty CP natives, examined in CP, were rated using a chronic mountain sickness (CMS) score to separate controls (10) from those with CMS (10), a maladaptation syndrome in natives to altitude which includes severe, recurring headache. We collected white cells in CP and, from the same men, within 1 h of arrival in Lima (150 m above sea level). Ten normal US men volunteered white cells for comparison. After RNA extraction we assessed gene expression by reverse transcription-polymerase chain reaction. Low ATP1A1 subunit of the ATPase gene mRNA expression in CP was correlated with headache ( P = 0.002), acral paraesthesias ( P = 0.004) and CMS score ( P < 0.001). ATP1A1 subunit expression was increased in all Andeans in Lima ( P < 0.001). There were no differences between Andean controls in Lima and US controls. Manipulation of Na+/K+ATPase could offer relief for migraineurs at sea level.

Low-energy vibrational spectra of flexible diphenyl molecules: biphenyl, diphenylmethane, bibenzyl and 2-, 3- and 4-phenyltoluene

Gas phase spectra of six bi-phenyl molecules are reported allowing an accurate determination of their active low-frequency vibrational modes.

Cannulation time is a more accurate measure of cannulation difficulty in endoscopic retrograde cholangiopancreatography than the number of attempts

BACKGROUND

Cannulation of the common bile duct (CBD) is the initial and sometime challenging step in endoscopic retrograde cholangiopancreatography (ERCP) procedure. Endoscopists often use cannulation attempts and cannulation time to grade cannulation difficulty, but a standard system has yet to be established. The objective of this study was to compare cannulation times with numbers of cannulation attempts, as measures of cannulation difficulty.

METHODS

We conducted a prospective study in a tertiary referral center, enrolling 58 patients who were undergoing ERCP for a variety of indications. Cannulation time and the number of cannulation attempts were recorded for each patient. A subset of 14 ERCPs had two observers assessing attempts at cannulation. Cannulation time, number of attempts and inter-observer variability in assessment of attempts were compared and studied.

RESULTS

The degree of agreement between two the methods (cannulation times and number of cannulation attempts) was unacceptable. There were considerable discrepancies between attempt tallies from two observers but the mean difference was statistically insignificant.

CONCLUSION

The grade of cannulation difficulty for a given ERCP procedure may differ when different methods are used (total cannulation time vs number of attempts); thus, grading by different methods should not be used interchangeably. Cannulation time is a more objective and more accurate assessment tool for grading cannulation difficulty than the number of attempts to cannulate the papilla.

Detection of the AT1 and AT2 receptors of angiotensin II in malignant breast tumors and its correlation to cellular proliferation, hormonal profile and prognosis

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Background: Angiotensin II (ANG II) is the main effector peptide of the Renin-Angiotensin-Aldosterone System. ANG II has multiple physiologic effects and recent studies have demonstrated that is an angiogenic factor in non-tumoral experimental models. We demonstrated that malignant glioma cells express both receptors and the blockage of AT1 inhibits tumoral growth in vivo, and induces apoptosis. Studies on the ANG II receptors’ subtypes in adenocarcinoma of the breast in mice have demonstrated high expression of AT1; nevertheless, their expression in breast cancer hasn’t been studied. The objective of this study was to determine the presence of the ANG II receptors AT1 and AT2 in human breast cancer and their association to vascularity, cellular proliferation, hormone receptors; as well as to the disease free survival. Methods: Malignant breast tumors (n = 78) from patients who underwent surgery were collected between 2000 and 2004. Patients with neoadjuvant chemotherapy or radiotherapy were excluded. The AT1 and AT2 receptor expression was performed by RT-PCR and immunohistochemistry. The control samples were 8 breast fibromas. Results: The median age of patients was 54.7 years, the pathological stage included stage I (15.5%), II (65.5%) and III (18.9%). The patients underwent radical mastectomy in 61.4 % and conservative surgery in 39%. The median survival was 82 ± 5 months. AT1 and AT2 expression was found in 66% and 55%, respectively The coexpression of AT1 and AT2 receptors was positive-positive in 55% o and negative-negative in 16% of the tumors (p = 0.045). None of the benign tumors showed AT1 and AT2 expression (p = 0.01). The associated factors survival were stage (p = 0.03, log rank = 0.05) and differentiation grade. The AT1 receptor expression was associated with presence of estrogen receptors (p = 0.05), mitosis index (p = 0.05), cellular proliferation index (p = 0.01) and vascular density (p = 0.05). Conclusions: There is an important expression of the ANG II receptors AT1 and AT2 in breast cancer. AT1 and AT2 participate in cellular proliferation mechanisms of breast cancer and may play an important role in its biology, thus making them potential therapeutic targets.

No significant financial relationships to disclose.

Single nucleotide polymorphisms (SNPs) at CDH1 promoter region in familial gastric cancer

INTRODUCTION

Gastric cancer is the most frequent gastrointestinal malignancy in Mexico and the proportion of patients younger than 40 years is one of the highest reported in the world literature. Recently several families with familial diffuse gastric cancer have been identified at the National Institute of Medical Sciences and Nutrition. Germline mutations in the E-cadherin gene (CHD1) have been described that result in the development of diffuse hereditary gastric cancer in young patients.

METHODS

The complete coding sequence at exons 1 to 16 and the promoter region of CDH1 was amplified by polymerase chain reaction in peripheral blood samples of two patients with early onset familial diffuse gastric cancer.

RESULTS

No germline inactivating mutations of CHD1 were found on either patient. Single nucleotide polymorphisms -160 C->A were detected in the promoter region of CDH1 in both patients.

CONCLUSIONS

The polymorphism -160 C->A theoretically confers an increased risk of developing diffuse gastric cancer. The relatives of these patients may an increased risk of gastric cancer among other tumors. There is presently not enough evidence to consider the -160 C->A polymorphism an etiologic factor of diffuse gastric cancer in these patients since the frequency and type of genetic alterations of CDH1 are largely unknown in the Mexican population. It will be necessary to conduct epidemiologic studies in the Mexican population to determine the influence that genetic alterations have on the genesis of diffuse gastric carcinoma.

An ectopic adrenocorticotropic hormone syndrome caused by a sacrococcygeal chordoma: report of a case with a slow progression

OBJECTIVE

To report the first case of an ectopic adrenocorticotropic hormone (ACTH) syndrome caused by a sacrococcygeal chordoma.

METHODS

We present a case report with clinical, laboratory, and histologic details.

RESULTS

A 76-year-old man was admitted to the hospital because of urinary obstruction. Five years previously, a urethral mass had been detected, and transurethral prostatectomy had been performed. Annual computed tomographic (CT) scans showed no change in size of the mass. In 1995, skin hyperpigmentation, central obesity, and bilateral edema were noted. The patient was admitted to the hospital in July 1996. A CT scan of the abdomen revealed a large mass close to the sacrum and compressing the bladder and rectum. Cortisol measurements (AM and PM) were 309 and 271 ng/mL, respectively. The plasma ACTH concentration was extremely elevated (3,125 pg/mL). Although resection of the mass was attempted, complete resection was not possible because the tumor had infiltrated the sacrum. Plasma cortisol concentrations in samples obtained 7 and 8 days postoperatively were normal. Plasma ACTH was substantially decreased (180 pg/mL) but remained above normal. The histologic features of the tumor were compatible with a chordoma. Neoplastic cells stained positively for ACTH.

CONCLUSION

This report describes the first case of an ectopic ACTH syndrome caused by a sacrococcygeal chordoma. A slow progression of symptoms in an ectopic ACTH syndrome had been described only for carcinoid tumors. These data add a new entry to the list of neoplasms capable of causing this syndrome.

Cerebral vasoreactivity in Andeans and headache at sea level

Headache is common in Cerro de Pasco (CP), Peru (altitude 4338 m) and was present in all patients with chronic mountain sickness (CMS) in CP reported here. Forty-seven percent of inhabitants report headache. Twenty-four percent of men have migraine with aura, with an average of 65 attacks a year. We assessed vasoreactivity of the cerebral vessels to CO2 by rebreathing and to NO by the administration of isosorbite dinitrate (IDN), a nitric oxide (NO) donor, using transcranial Doppler ultrasound in the middle cerebral artery (MCA) in natives of CP, some of whom suffered from CMS. We repeated the measurements in Lima (altitude 150 m) in the same subjects within 24 h of arrival. Vasodilatation in the middle cerebral artery supply territory in response to CO2 and NO, both physiologic vasodilators, is defective in Andean natives at altitude and in the same subjects at sea level. Incapacitating migraine can occur with impaired cerebral vasoreactivity to physiologic vasodilators. We propose that susceptibility to migraine might depend in part on gene expression with consequent alterations of endothelial function.

Sleep-related hypoxaemia and excessive erythrocytosis in Andean high-altitude natives

To determine whether nocturnal hypoxaemia contributes to the excessive erythrocytosis (EE) in Andean natives, standard polysomnographies were performed in 10 patients with EE and in 10 controls (mean haematocrit 76.6 +/- 1.3% and 5.4 +/- 0.8%, respectively) living at an altitude of 4,380 m. In addition, the effect of O2 administration for 1 h prior to sleep, and the relationship between the hypoxic/hypercapnic ventilatory response and the apnoea/hypopnoea index (AHI) during sleep were studied. Awake arterial oxygen saturation (Sa,O2) was significantly lower in patients with EE than in controls (83.7 +/- 0.3% versus 85.6 +/- 0.4%). In both groups, the mean Sa,O2 significantly decreased during sleep (to 80.0 +/- 0.8% in EE and to 82.8 +/- 0.5% in controls). The mean Sa,O2 values remained significantly lower in patients with EE than in controls at all times of the night, and patients with EE spent significantly more time than the controls with an Sa,O2 of <80%. There were no differences between the two groups in the number and duration of the apnoeas/hypopnoeas. None of these variables were affected by O2 administration. In both groups the AHI positively correlated with the hypercapnic ventilatory response. Andean natives undergo minor respiratory disorders during sleep. The reduction in oxygen saturation found in subjects with excessive erythrocytosis was small, yet consistent and potentially important, as it remained below the threshold known for the increase in erythropoietin stimulation. This may be an important factor promoting erythropoiesis, but its relevance needs to be further explored.

Autonomic cardiovascular function in high-altitude Andean natives with chronic mountain sickness

We evaluated autonomic cardiovascular regulation in subjects with polycythemia and chronic mountain sickness (CMS) and tested the hypothesis that an increase in arterial oxygen saturation has a beneficial effect on arterial baroreflex sensitivity in these subjects. Ten Andean natives with a Hct >65% and 10 natives with a Hct <60%, all living permanently at an altitude of 4,300 m, were included in the study. Cardiovascular autonomic regulation was evaluated by spectral analysis of hemodynamic parameters, while subjects breathed spontaneously or frequency controlled at 0.1 and 0.25 Hz, respectively. The recordings were repeated after a 1-h administration of supplemental oxygen and after frequency-controlled breathing at 6 breaths/min for 1 h, respectively. Subjects with Hct >65% showed an increased incidence of CMS compared with subjects with Hct <60%. Spontaneous baroreflex sensitivity was significantly lower in subjects with high Hct compared with the control group. The effects of supplemental oxygen or modification of the breathing pattern on autonomic function were as follows: 1) heart rate decreased significantly after both maneuvers in both groups, and 2) spontaneous baroreflex sensitivity increased significantly in subjects with high Hct and did not differ from subjects with low Hct. Temporary slow-frequency breathing may provide a beneficial effect on the autonomic cardiovascular function in high-altitude natives with CMS.

Ventilatory and cardiovascular responses to hypoxia and exercise in Andean natives living at sea level

This study was designed to determine in subjects born at high altitude who move to sea level (HA-SL: born at 3500 m or above; n = 25) whether their cardiorespiratory responses to hypoxia and exercise are similar to those of sea level natives (SL,n = 25). The average age (39 +/- 7.3 yr), weight (72 +/- 7.3 kg), and height (1.71 +/- 0.01 m) did not differ between the SL and HA-SL subjects. All subjects were studied at rest or during exercise (60 W on cycle ergometer) while breathing room air (F(IO2) = 0.21 and P(B) = 760) or hypoxia (F(IO2) = 0.115 and PB = 760) in the following order: (1) normoxia at rest (NX-Rs), (2) hypoxia at rest (HX-Rs, 11.5% O(2)), hypoxia at exercise (HX-Ex), and normoxia at exercise (NX-Ex). Each period lasted 5 min. In absolute values, HA-SL showed significantly higher ventilation (V(E), L/min) during exercise in both normoxia and hypoxia and higher oxygen saturation (Sa(O2), %) during hypoxia both at rest and in exercise. They also had lower end-tidal CO(2) values (P(ETCO2), torr) at rest in both normoxia and hypoxia, but a higher P(ETCO2) in hypoxic exercise. Heart rate (HR, beats/min) was lower at rest in both normoxia and hypoxia, but higher in exercise. With acute hypoxia, Sa(O2) decreased less in the HA-SL than in the SL at rest (HA-SL, 9.2 +/- 0.8; SL, 12.0 +/- 0.82) and during exercise (HA-SL, 18.3 +/- 1.1; SL, 21.2 +/- 1.2). In conclusion, this study shows that HA-SL natives have increased ventilation and heart rate during exercise once their lifelong hypoxia is relieved.

Floral transcription factor AGAMOUS interacts in vitro with a leucine-rich repeat and an acid phosphatase protein complex

We are interested in identifying potential protein interactors of MADS domain transcription factors during Arabidopsis thaliana flower development. We based our biochemical search on a conserved motif in the MADS domain that includes putative phosphatase and phosphorylation sites that may mediate protein interactions. An affinity column with this motif and a few surrounding hypervariable amino acids derived from the AGAMOUS sequence was prepared and used to isolate potential interactors from floral crude extracts. Only two proteins were specifically bound to the affinity column. The first corresponds to a carpel specific storage protein, VSP1, that presents acid phosphatase activity, and the second is a novel leucine-rich repeat protein that we have named FLOR1. Coimmunoprecipitation, two-hybrid yeast, and affinity column assays show that the FLOR1-VSP1 complex interacts with AGAMOUS and that this transcription factor directly interacts with FLOR1. This is the first assay to show an interaction between plant MADS domain factors and non-MADS proteins.

Phytotoxic naphthopyranone derivatives from the coprophilous fungus Guanomyces polythrix

Reinvestigation of the fermentation broth and mycelium of the coprophilous fungus Guanomyces polythrix, grown in static conditions, led to the isolation of several phytotoxic compounds, including two new naphthopyranone derivatives, namely (2S, 3R)-5-hydroxy-6,8-dimethoxy-2,3-dimethyl-2,3-dihydro-4H-naphtho[2,3-b]-pyran-4-one and (2S, 3R)-5-hydroxy-6,8,10-trimethoxy-2,3-dimethyl-2,3-dihydro-4H-naphtho[2,3-b]-pyran-4-one. The structures of the new compounds were established by spectral and chiroptical methods. In addition, the structure of 8-hydroxy-6-methyl-9-oxo-9H-xanthene-1-carboxylic acid methyl ester was unambiguously determined by X-ray analysis. The isolates caused significant inhibition of radicle growth of two weed seedlings (Amaranthus hypochondriacus and Echinochloa crusgalli) and interacted with both spinach and bovine brain calmodulins.

Hematological parameters in high altitude residents living at 4,355, 4,660, and 5,500 meters above sea level

There have been a number of reports describing the hematological indicators of Andean residents living at altitudes above 4,000 m, but several confounding factors have made the published results difficult to interpret. To clear up the effect of hypoxia on hemoglobin concentration (Hb, g/dL), hematocrit (Hct, %) and red blood cell concentration (RBC, cells/microL), this publication describes and analyzes these variables in children, men, and women from three large and homogeneous populations living at 4,355 m (n = 151), 4,660 m (n = 400), and 5,500 m (n = 273) in the Southern Peruvian Andes. Hb, Hct, and RBC increase with age in men (p < 0.001), as well as in women (p < 0.001) at the three altitudes of the study. In children (boys and girls) living at 5,500, Hb increases 11% when compared with children living at 4,355 m, and in adults, Hb increases 9.6% when comparing the same altitudes. The maximum percentage increase in Hb with age was 5.6% at 5,500 m, in men and 3.2% at 4,355 m, in women. The average percentage of difference for the Hb concentration between adult men and women is 6.6% at 4,355 m, 9.8% at 4,660 m, and 11.6% at 5,500 m. The differences in Hb concentration between men and women can only be seen after puberty. Finally, Hb is higher in older than younger women, which confirms the role of menopause in the development of erythremia. The result of this analysis reinforces the notion that Hb and Hct seem to be stable and useful parameters for acclimatization only at moderate altitudes; with aging or with increasing altitude, they may become excessive and lose their efficiency to protect the venous oxygen pressure.

Phytotoxic compounds from the new coprophilous fungus guanomyces polythrix

Bioactivity-directed fractionation of the fermentation broth and mycelium of the coprophilous fungus Guanomyces polythrix led to the isolation of several phytotoxic compounds, including five new naphthopyranone derivatives (1-5). In addition, rubrofusarin B, emodin, citrinin, and 4-hydroxybenzoic acid methyl ester were obtained. The structures of the new compounds were established by spectral and chiroptical methods. The isolates caused significant inhibition of radicle growth of two weed seedlings (Amaranthus hypochondriacus and Echinochloa crusgalli) and interacted with both spinach and bovine brain calmodulins.

Carbonic anhydrase activity in the red blood cells of sea level and high altitude natives

Red blood cell carbonic anhydrase (CA) activity has not been studied in high altitude natives. Because CA is an intraerythocytic enzyme and high altitude natives are polycythemic, it is important to know if the activity of CA per red cell volume is different from that of their sea level counterparts. Blood was collected from healthy subjects living in Lima (150m) and from twelve subjects from Cerro de Pasco (4330m), and hematocrit and carbonic anhydrase activity were measured. As expected, the high altitude natives had significantly higher hematocrits than the sea level controls (p = 0.0002). No difference in the CA activity per milliliter of red cells was found between the two populations. There was no correlation between the hematocrit and CA activity.

[Diagnosis of malignant and benign insulinoma. Experience of the National Institute of Nutrition]

INTRODUCTION

Insulinomas are uncommon tumors, their incidence is approximately one case for 1 million population per year.

OBJECTIVE

To expose our experience in the diagnosis of these tumors at the Instituto Nacional de la Nutrición Salvador Zubirán.

MATERIAL AND METHODS

All patients with histologic diagnosis of insulinoma were reviewed; the period was from 1959 to 1996. The methods used for diagnosis and localization as well as the clinical picture according to the benignity or malignity of the tumor were registered.

RESULTS

Eighteen patients were included, four of them with malignant tumors. In two patients islet cell tumors occurred in association with MEN type I, one of them benign and the other malignant. The mean age of patients with benign tumor was 38.2 +/- 13.5 years, in those with malignant tumors it was 51.5 +/- 16.2 years. The median period between symptoms and diagnosis was 34.4 +/- 15 months for benign tumors and 6 +/- 1.1 months for those with malignant tumors (p = 0.02). Patients with increasing weight had benign tumors. The 24 hours fasting test was not done in patients with malignant tumors because of the severity of hypoglycemia. The insulin/glucose ratio in patients with a malignant tumor was 5.2 +/- 4.7, while in patients with a benign tumor it was 1.82 +/- 1.7. The imaging studies showed that three patients with malignant tumors had hepatic metastasis and one had lymph node metastasis. The low accuracy of localization by radiological methods is due to the size of the tumor (> 2 cm).

CONCLUSIONS

Malignant insulinomas are more aggressive and the delay of diagnosis is shorter that in cases with benign tumors. Selective arteriography remains the best preoperative localization procedure.

Experimental studies on the effect of lidocaine on wound healing

Local anesthetics have several effects on wound healing. In experimental studies, procaine at high concentrations has been proved to retard healing in surgical wounds by diminishing the synthesis of mucopolysaccharides and hence probably collagen. Other studies have shown that lidocaine and bupivacaine inhibit collagen synthesis in fibroblast tissue cultures in rats. This study was designed to evaluate the effect of lidocaine on wound healing. An experimental, prospective, comparative, crossover and double-blind study was designed. Forty male guinea pigs, weighing 300 to 600 g, were randomly assigned to two groups. In control group A (20 animals), skin and subcutaneous tissue in a clean wound were incised and infiltrated with regular saline solution; in group B 20 animals were infiltrated with 1% lidocaine. All animals were sacrificed on day 8 and evaluated for breaking strength, number of collagen fibers by morphometry, and histologic examination of collagenization, edema, vascularity, and presence of acute and chronic inflammatory cells. The histopathologic appearance of tissues infiltrated with lidocaine did not vary consistently in relation to collagenization, edema, or acute and chronic inflammatory processes. The mean breaking strength between both groups was not statistically significant (p = 0.120). Important statistical differences were observed in vascularity (p < 0.003) and morphometric results (p < 0.001), where collagen was found in small amounts in the lidocaine group. The results of this study suggest that local infiltration of lidocaine produces significant histopathologic changes, but it does not substantially alter wound healing as there were no differences in the breaking strength of the wounds.

Atypical diffuse Lewy body disease with neuritic abnormalities

Dementia associated with cortical and subcortical Lewy bodies (LB's) is a distinct entity with variable clinico-pathological presentation. We present the case of a 49-year-old male with progressive dementia. At autopsy, the brain showed diffuse cortical atrophy and ubiquitin-positive LB's in the dentate gyrus, deep layers of the neocortex, basal ganglia, nucleus basalis and substantia nigra. Thioflavine S stains of the neocortex and hippocampus were negative for the presence of plaques and tangles. Anti-ubiquitin immunostaining revealed abundant dystrophic neurites, torpedo-like axons and abnormal neuritic processes in the molecular layer of the dentate gyrus, pyramidal cell layer in CA1, subiculum, deep layers of the neocortex, claustrum, caudate, putamen and globus pallidus. Relatively mild neuritic alterations were observed in the nucleus basalis of Meynert (NbM) and locus ceruleus. The presence of this unique type of axonal damage associated with Lewy body disease, in the absence of plaques and tangles, might suggest a divergent mechanism of neuritic injury in the wide spectrum of this disorder.