STYLE (NCT03449173) a phase II Trial of Sunitinib in patients with type B3 Thymoma or Thymic Carcinoma in second and further lines

BACKGROUND

Thymic malignancies are rare tumors with few therapeutic options. The STYLE trial was aimed to evaluate activity and safety of sunitinib in advanced/recurrent type B3 thymoma (T) and thymic carcinoma (TC).

METHODS

In this multicenter Simon 2 stages phase II trial, patients with pretreated T/TC were enrolled in two cohorts and assessed separately. Sunitinib was administered 50mg daily for 4-weeks, followed by a 2-week rest period (schedule 4/2), until disease progression or unacceptable toxicity. The primary endpoint was objectives response rate (ORR). Progression free survival (PFS), overall survival (OS), disease control rate (DCR) and safety were secondary endpoints.

RESULTS

From 03/2017 to 01/2022, 12 T and 32 TC patients were enrolled. At stage 1 ORR was 0% (90%CI 0.0-22.1) in T and 16.7% (90%CI 3.1-43.8) in TC, so T cohort was closed. At stage 2, the primary endpoint was met for TC with ORR of 21.7% (90%CI 9.0%-40.4%). In the ITT analysis DCR was 91.7% (95%CI 61.5%-99.8%) in Ts and 89.3% (95%CI 71.8%-97.7%) in TCs. mPFS was 7.7 months (95%CI 2.4-45.5) in Ts, 8.8 (95%CI 5.3-11.1) in TCs; mOS was 47.9 months (95%CI 4.5-not reached) in Ts, and 27.8 (95%CI 13.2-53.2) in TCs. Adverse events (AEs) occurred in 91.7% T and 93.5% TCs. Grade ≥3 treatment-related AEs were reported in 25.0% T and 51.6% TC.

CONCLUSIONS

This trial confirms the activity of sunitinib in TC patients, supporting its use as second line treatment.

Towards texture accurate slice interpolation of medical images using PixelMiner

Quantitative image analysis models are used for medical imaging tasks such as registration, classification, object detection, and segmentation. For these models to be capable of making accurate predictions, they need valid and precise information. We propose PixelMiner, a convolution-based deep-learning model for interpolating computed tomography (CT) imaging slices. PixelMiner was designed to produce texture-accurate slice interpolations by trading off pixel accuracy for texture accuracy. PixelMiner was trained on a dataset of 7829 CT scans and validated using an external dataset. We demonstrated the model's effectiveness by using the structural similarity index (SSIM), peak signal to noise ratio (PSNR), and the root mean squared error (RMSE) of extracted texture features. Additionally, we developed and used a new metric, the mean squared mapped feature error (MSMFE). The performance of PixelMiner was compared to four other interpolation methods: (tri-)linear, (tri-)cubic, windowed sinc (WS), and nearest neighbor (NN). PixelMiner produced texture with a significantly lowest average texture error compared to all other methods with a normalized root mean squared error (NRMSE) of 0.11 (p < .01), and the significantly highest reproducibility with a concordance correlation coefficient (CCC) ≥ 0.85 (p < .01). PixelMiner was not only shown to better preserve features but was also validated using an ablation study by removing auto-regression from the model and was shown to improve segmentations on interpolated slices.

PEOPLE (NCT03447678), a first-line phase II pembrolizumab trial, in negative and low PD-L1 advanced NSCLC: clinical outcomes and association with circulating immune biomarkers

BACKGROUND

The PEOPLE trial aimed to identify new immune biomarkers in negative and low programmed death-ligand 1 (PD-L1) (0%-49%) advanced non-small-cell lung cancer (aNSCLC) patients treated with first-line pembrolizumab. Here we report the main outcomes and the circulating immune biomarkers analysis.

PATIENTS AND METHODS

The primary endpoint of this phase II trial was the identification of immune biomarkers associated with progression-free survival (PFS). Overall survival (OS), objective response rate (ORR), disease control rate (DCR), duration of response (DoR) and safety were secondary endpoints. Absolute cell counts for 36 subsets belonging to innate and adaptive immunity were determined by multiparametric flow cytometry in peripheral blood at baseline and at first radiologic evaluation. An orthoblique principal components-based clustering approach and multivariable Cox regression model adjusted for clinical variables were used to analyze immune variables and their correlation with clinical endpoints.

RESULTS

From May 2018 to October 2020, 65 patients were enrolled. After a median follow-up of 26.4 months, the median PFS was 2.9 months [95% confidence interval (CI) 1.8-5.6 months] and median OS was 12.1 months (95% CI 8.7-17.1 months). The ORR was 21.5%, DCR was 47.7% and median DoR was 14.5 months (95% CI 6.4-24.9 months). Drug-related grade 3-4 adverse events were 9.2%. Higher T cell and natural killer (NK) cell count at baseline and at the first radiologic evaluation were associated with improved PFS, DCR and OS. On the contrary, higher myeloid cell count at baseline or at the first radiologic evaluation was significantly associated with worse OS and DCR.

CONCLUSIONS

Circulating immune biomarkers can contribute to predict outcomes in negative and low PD-L1 aNSCLC patients treated with first-line single-agent pembrolizumab.

POS0264 THE EMERGING ROLE OF MAGNETIC RESONANCE IMAGING IN INTERSTITIAL LUNG DISEASE IN SYSTEMIC SCLEROSIS: EVIDENCE FOR ULTRA SHORT TE AND COMPRESSED SENSING VIBE ACQUISITIONS AS PROMISING TOOLS FOR THE EVALUATION OF PARENCHYMAL ALTERATIONS

Background:

Interstitial lung disease (ILD) is a frequent complication and the major cause of death in Systemic sclerosis (SSc). Computed tomography (CT) is the gold standard imaging technique to assess ILD but is burdened by exposure to ionizing radiations that limits its use for the follow-up. MRI sequences with Ultra Short Echo Time (UTE) are promising for ILD.

Objectives:

We tested two MRI sequences, UTE Spiral VIBE and Compressing Sensing (CS) VIBE, in SSc-ILD, in comparison to chest CT.

Methods:

SSc patients with suspected-ascertained ILD were evaluated for undergoing CT-MRI examinations in the same day. Two radiologists visually scored the extent of ground glass opacities (GGO), reticulations, honeycombing and consolidations on CT-MRI. The sum of alteration was assumed as ILD extent. A quantitative texture analysis (qCT) was also performed on CT. Cohen’s k was adopted for interreader concordance in ILD detection. MRI sensitivity and specificity in ILD detection were evaluated. Lin’s concordance was adopted to compare extent analysis between readers and between CT (visual and qCT analysis) and MRI sequences.

Results:

54 patients performed both CT and MRI. MRI interreader concordance was moderate in ILD detection, while ILD and GGO extent analysis showed good or very good concordance. UTE Spiral VIBE had a sensitivity and specificity in ILD detection of 95.8% and 77.8%, while alterations extent analysis obtained a very good concordance with CT for ILD and GGO. CS VIBE showed a sensitivity and specificity in ILD detection of 46.7% and 95.0%, but a slight or fair concordance with CT in all alterations’ extent analysis.

Conclusion:

MRI UTE Spiral VIBE sequences are helpful in the evaluation of SSc-ILD. Larger cohorts of patients will be needed to confirm that MRI may be useful in clinical practice, reducing the radiological load of chest CT

References:

[1]Romei C, Turturici L, Tavanti L, et al. The use of chest magnetic resonance imaging in interstitial lung disease: a systematic review. Eur Respir Rev. 2018;27(150):180062. Doi:10.1183/16000617.0062-2018

[2]Miller GW, Mugler JP, Sá RC, Altes TA, Prisk GK, Hopkins SR. Advances in functional and structural imaging of the human lung using proton MRI. NMR Biomed. 2014;27(12):1542-1556. doi:10.1002/nbm.3156

[3]Pinal-Fernandez I, Pineda-Sanchez V, Pallisa-Nuñez E, et al. Fast 1.5 T chest MRI for the assessment of interstitial lung disease extent secondary to systemic sclerosis. Clin Rheumatol. 2016;35(9):2339-2345. doi:10.1007/s10067-016-3267-0

[4]Ohno Y, Koyama H, Yoshikawa T, et al. Pulmonary high-resolution ultrashort TE MR imaging: Comparison with thin-section standard- and low-dose computed tomography for the assessment of pulmonary parenchyma diseases: Pulmonary MRI with UTE in Pulmonary Disease. J Magn Reson Imaging. 2016;43(2):512-532. doi:10.1002/jmri.25008

Disclosure of Interests:

None declared

KEAP1-driven co-mutations in lung adenocarcinoma unresponsive to immunotherapy despite high tumor mutational burden

BACKGROUND

Immune checkpoint inhibitors (ICIs) have demonstrated significant overall survival (OS) benefit in lung adenocarcinoma (LUAD). Nevertheless, a remarkable interpatient heterogeneity characterizes immunotherapy efficacy, regardless of programmed death-ligand 1 (PD-L1) expression and tumor mutational burden (TMB). KEAP1 mutations are associated with shorter survival in LUAD patients receiving chemotherapy. We hypothesized that the pattern of KEAP1 co-mutations and mutual exclusivity may identify LUAD patients unresponsive to immunotherapy.

PATIENTS AND METHODS

KEAP1 mutational co-occurrences and somatic interactions were studied in the whole MSKCC LUAD dataset. The impact of coexisting alterations on survival outcomes in ICI-treated LUAD patients was verified in the randomized phase II/III POPLAR/OAK trials (blood-based sequencing, bNGS cohort, N = 253). Three tissue-based sequencing studies (Rome, MSKCC and DFCI) were used for independent validation (tNGS cohort, N = 289). Immunogenomic features were analyzed using The Cancer Genome Atlas (TCGA) LUAD study.

RESULTS

On the basis of KEAP1 mutational co-occurrences, we identified four genes potentially associated with reduced efficacy of immunotherapy (KEAP1, PBRM1, SMARCA4 and STK11). Independent of the nature of co-occurring alterations, tumors with coexisting mutations (CoMut) had inferior survival as compared with single-mutant (SM) and wild-type (WT) tumors (bNGS cohort: CoMut versus SM log-rank P = 0.048, CoMut versus WT log-rank P < 0.001; tNGS cohort: CoMut versus SM log-rank P = 0.037, CoMut versus WT log-rank P = 0.006). The CoMut subset harbored higher TMB than the WT disease and the adverse significance of coexisting alterations was maintained in LUAD with high TMB. Significant immunogenomic differences were observed between the CoMut and WT groups in terms of core immune signatures, T-cell receptor repertoire, T helper cell signatures and immunomodulatory genes.

CONCLUSIONS

This study indicates that coexisting alterations in a limited set of genes characterize a subset of LUAD unresponsive to immunotherapy and with high TMB. An immune-cold microenvironment may account for the clinical course of the disease.

SAT0553 QUANTITATIVE ANALYSIS OF IMAGING FEATURES AT CHEST CT OF PULMONARY ARTERIAL AND VENOUS COMPONENTS IN SYSTEMIC SCLEROSIS-INTERSTITIAL LUNG DISEASE (SSc-ILD)

Background:

Interstitial lung disease (ILD) and pulmonary arterial hypertension carry a negative impact on SSc prognosis. Chest CT is the gold standard in assessing ILD and helps in evaluating associated vascular involvement.

Objectives:

As qualitative analysis of CT scans is limited by low reproducibility and time constraints, we aimed at evaluating parenchymal and vascular features in SSc-ILD by quantitative analysis (QA) of CT scans and testing the relationship with clinical-functional data.

Methods:

We prospectively enrolled 80 patients who underwent PFTs and chest CT scan spirometry gated at TLC on the same day. Clinical, lung functional and diffusion data, as well as disability indexes were collected. CT images were analyzed by a computational platform for texture analysis of ILD patterns (CALIPER), through Imbio LTA. It quantified the extent of normal pattern (NP %), ground glass opacities (GG %), reticulation (RET %), honeycombing (HC %), total ILD extent (ILD EXT %) and hyperlucent (HL %). Low density areas, representing emphysematous area, were also quantified (LDA %). For lung vessel analysis, a software program developed by the Ludwig Boltzmann Institute for Lung Vascular Research was used. This software determined total, arterial, and venous vascular volumes (TV, AV, VV), and relative volumes (TV%, AV%, VV%), as well as density and number for total, arterial and venous vessels.

Results:

43/80 patients/CT scans were eligible for both software analyses, while 36/43 for arterial and venous separation. TV% and total vessel density were correlated positively with mRSS and negatively with %FVC (r=-0.537 and r=-0.382) and %TLC (r=-0.511 and r=-0.648), while vessel tortuosity correlated positively with %DLco. This was confirmed when separately analyzing arterial vessels, while VV% negatively correlated with %FVC, %TLC and %DLco. There was a positive correlation between %ILD patterns and %vascular volumes, being significant for TV%-AV%, total vessels and arterial density. Conversely, %ILD patterns were negatively correlated with VV and number of veins detected, despite positive correlation between VV% and ILD_EXT%. When clustering patients according to %FVC and %DLco with 80% normal cutoff, %FVC allowed clustering according to significantly different ILD patterns extents and vascular features, while %DLCO for vascular features only. Moreover, the consecutive addition of functional impairment and worsening of ILD (from both normal %FVC and %Dlco, to %DLco impairment only to both %FVC and %Dlco impairment), there was a significant increase in %TV, % AV and %VV, with the exception of decrease in %VV and venous density in patients with double impairment versus DLco single impairment.

Conclusion:

This is the first study showing in SSc a direct correlation between ILD and the increase in lung vascular volume, which is characterized by increase in arterial volume and density and reduction in venous volume and number. These results might be explained by the reduction of pulmonary volume due to fibrosis. However, also a para-physiological mechanism of redistribution of blood flow in lung areas, less involved by ILD, might be considered. Further studies on lung vessel quantification and distribution are ongoing.

Disclosure of Interests:

Cosimo Bruni Speakers bureau: Actelion, Eli Lilly, Mariaelena Occhipinti Consultant of: Imbio, Gianna Camiciottoli: None declared, Maurizio Bartolucci: None declared, Michael Pienn: None declared, Gemma Lepri: None declared, Alessio Fabbrizzi: None declared, Alessandra Tottoli: None declared, Giuglia Ciardi: None declared, Dilia Giuggioli: None declared, Giovanna CUOMO: None declared, Francesco Masini: None declared, Horst Olschewski: None declared, Federico Lavorini: None declared, Linda Calistri: None declared, Marco Matucci-Cerinic Grant/research support from: Actelion, MSD, Bristol-Myers Squibb, Speakers bureau: Acetelion, Lilly, Boehringer Ingelheim

OP0181 FUNCTIONAL CUT-OFFS TO DISTINGUISH PULMONARY VASCULAR AND PARENCHYMAL INVOLVEMENT IN SYSTEMIC SCLEROSIS (SSC): A QUANTITATIVE ANALYSIS OF IMAGING FEATURES AT CHEST COMPUTED TOMOGRAPHY (CT)

Background:

Interstitial lung disease (ILD) and pulmonary arterial hypertension represent the most frequent causes of morbidity and mortality in SSc, with chest CT representing the gold standard in ILD assessment, while FVC and DLco allow functional assessment.

Objectives:

As qualitative analysis of given chest CT scans is hampered by low reproducibility, we aimed to perform a quantitative analysis (QA) of CT scans able to investigate the parenchymal and vascular features in SSc-ILD and thus testing the relationship with clinical-functional data.

Methods:

We prospectively enrolled 80 patients who underwent PFTs and spirometry-gated chest CT scan at TLC on the same day. Clinical, lung functional and diffusion data, as well as disability indexes were collected. CT images were analyzed by a computational platform for texture analysis of ILD patterns (CALIPER) through Imbio LTA. It quantified the extent of normal lung (%N), ground-glass opacities (%GG), reticulation (%RET), honeycombing (%HC), hyperlucent (%HL), absolute (PVV, cm3) and normalized (PVV/LV, %) pulmonary vascular volumes. Cut-offs of normality for %FVC and %DLco of 80% and 70% were tested to differentiate parenchymal and vascular features.

Results:

73 patients/CT scans were eligible for both software analyses. CALIPER showed GG% as the most frequent radiological pattern (mean 5.5±10.4%). %FVC and % TLC negatively correlated with all ILD patterns, while %DLco with RET% only; PVV and PVV/LV negatively correlated with %FVC and %TLC, while %DLco with PVV/LV only. Positive correlations were found between all ILD patterns and vascular volumes (Table 1).

LV (cm3)%N%GG%RET%HC%HLPVV (cm3)% PVV/LVFVC%r.60-.19-.40-.34-.30.35-.26-.44p<.001-<.001.004.01.003.04<.001FEV1%r.58-.02-.38-.25-.24.23-.35-.49p<.001-.002.04.05-.004<.001FEV1/FVCr-.16.33.22.16.21-.35-.15-.08p-.02------TLC%r.71-.14-.42-.37-.48.40-.43-.64p<.001-.001.01<.001.002<.001<.02DLco%r.38-.05-.21-.31-.22.30-.21-.33p.01--.01---.006FVC/DLcor.03-.08-.06-.003-.09.08-.06-.08p--------

Cut-offs equal to 80 for %FVC and 70 for %DLco distinguished both parenchymal and vascular features, while 80 for %DLco characterized vascular features only. These results were confirmed also when patients were stratified according to absent/single/combined %FVC and %DLCO impairments with 80% cut-offs (Table 2).

FVC<80%FVC ≥80%pDLco<80%DLco ≥80%pDLco <70%DLco ≥70%p%N82.7 (9.6)86.2 (14.7)-86.6 (12.7)80.8 (15.8)-84.1 (13.9)86.4 (13.5)-%GG10.3 (8.9)2.4 (3.9)<.0015.0 (6.7)3.9 (6.9)-6.2 (7.5)2.4 (4.8).002%RET2.9 (2.9)0.8 (1.3)<.0011.6 (2.1)0.7 (0.9)-1.9 (2.4)0.6 (0.8).007%HC0.4 (0.6)0.1 (0.1)<.0010.2 (0.3)0.1 (0.1)-0.2 (0.4)0.05 (0.2).010%HL3.6 (6.8)8.9 (12.1)-5.4 (8.8)14.1 (15.4).0506.3 (10.1)9.2 (12.7)-PVV125.6 (39.1)90.9 (26.9)<.001101.9 (34.8)84.7 (19.4).016106.9 (38.3)87.5 (20.5).012PVV/LV3.8 (1.6)2.0 (0.7)<.0012.51 (1.3)1.7 (0.6).0022.76 (1.4)1.83 (0.6).001

Conclusion:

In SSc a cut-off at 80 for %DLco may help identifying vascular changes as automatically assessed on chest CT scan, without any underlying ILD. The 80% cut-off for %DLco may be proposed to identify isolated vascular involvement, while %FVC at 80% or %DLco at 70% to identify significant parenchymal involvement. These results need to be confirmed in larger multi-centric cohorts.

Disclosure of Interests:

Cosimo Bruni Speakers bureau: Actelion, Eli Lilly, Mariaelena Occhipinti Consultant of: Imbio, Gianna Camiciottoli: None declared, Maurizio Bartolucci: None declared, Gemma Lepri: None declared, Alessio Fabbrizzi: None declared, Alessandra Tottoli: None declared, Anna Bassetto: None declared, Giuglia Ciardi: None declared, Dilia Giuggioli: None declared, Giovanna CUOMO: None declared, Francesco Masini: None declared, Federico Lavorini: None declared, Linda Calistri: None declared, Marco Matucci-Cerinic Grant/research support from: Actelion, MSD, Bristol-Myers Squibb, Speakers bureau: Acetelion, Lilly, Boehringer Ingelheim

Prevention by metformin of alterations induced by chronic exposure to high glucose in human islet beta cells is associated with preserved ATP/ADP ratio

AIM

We have explored whether the insulin secretory defects induced by glucotoxicity in human pancreatic islets could be prevented by metformin and investigated some of the possible mechanisms involved.

METHODS

Human pancreatic islets and INS-1E cells were cultured for 24h with or without high glucose (16.7mM) concentration in the presence or absence of therapeutical concentration of metformin and then glucose-stimulated insulin release, adenine nucleotide levels and mitochondrial complex I and II activities were measured. Islet ultrastructure was analyzed by electron microscopy.

RESULTS

Compared to control islets, human islets cultured with high glucose showed a reduced glucose-stimulated insulin secretion that was associated with lower ATP levels and a lower ATP/ADP ratio. These functional and biochemical defects were significantly prevented by the presence of metformin in the culture medium, that was also able to significantly inhibit the activity of mitochondrial complex I especially in beta cells exposed to high glucose. Ultrastructural observations showed that mitochondrial volume density was significantly increased in high glucose cultured islets. The critical involvement of mitochondria was further supported by the observation of remarkably swollen organelles with dispersed matrix and fragmented cristae. Metformin was able to efficiently prevent the appearance of all these ultrastructural alterations in human islets exposed to high glucose.

CONCLUSIONS

Our results show that the functional, biochemical and ultrastructural abnormalities observed in human islet cells exposed to glucotoxic condition can be significantly prevented by metformin, further highlighting a direct beneficial effect of this drug on the insulin secreting human pancreatic beta cells.

[Ocra Method: development of a new procedure for analysis of multiple tasks subject to infrequent rotation]

In the Ocra methods (Ocra index and Ocra Checklist), when computing the final indices (Ocra index or checklist score), in the case of more than one repetitive task a "traditional" procedure was already proposed, the results of which could be defined as "time-weighted average". This approach appears to be appropriate when considering rotations among tasks that are performed very frequently, for instance almost once every hour (or for shorter periods). However, when rotation among repetitive tasks is less frequent (i.e. once every 1 1/2 or more hours), the "time-weighted average" approach could result in an underestimation of the exposure level (as it practically flattens peaks of high exposures). For those scenarios an alternative approach based on the "most stressful task as minimum" might be more realistic. This latter approach has already been included in the NIOSH approach for multiple sequential lifting tasks and, given the recent availability in the Ocra method of more detailed duration multipliers (practically one different Du(M) for each different step of one hour of duration of the repetitive task), it is now possible to define a particular procedure to compute the complex Ocra Multitask Index (cOCRA) and the complex Checklist Score (cCHESCO) for the analysis of two or more repetitive tasks when rotations are infrequent (rotations every 1 1/2 hours or more). The result of this approach will be at least equal to the index of the most stressful task considered for its individual daily duration and at the most equal to the index of the most stressful task when it is (only theoretically) considered as lasting for the overall daily duration of all examined repetitive tasks. The procedure is based on the following formula: Complex Ocra Multitask Index = Ocra(1(Dum1) + (Delta ocra1xK) where 1,2,3,...,N = repetitive tasks ordered by ocra index values (1 = highest; N = lowest) computed considering respective real duration multipliers (Dum(i)). ocra1 = ocra index of task, considering Dum(1). Dum(i) = duration multiplier for task(i) real duration. Dum(tot) = duration multiplier for total duration of all repetitive tasks. delta ocra1 = highest ocra index among N tasks considering Dum(tot) (ocra(i max)) - ocra index of task1 considering Dum1. K = (ocra(1 max)*FT1) + (ocra(2 max)*FT2) + ... + (ocra (N)*FT(N)) over (ocra(i max)). ocral,Nm(1,N MAX) = index of tasks 1 to Ncons idering Dum,, (tot)7=Fr(i) c tion of Time (values from 0 to 1) of task; wi(i)h respect to the total repetitive time.

Fraley's Syndrome. A Nephron-Sparing Laparoscopic Surgical Procedure. Case Report

16-year-old girl with Fraley's syndrome, which caused right flank pain and urinary infection. The radiologic exam showed a distended calyx and an infundibular obstruction caused by compression of normal renal vessels. Retroperitoneal laparoscopic calycectomy and closure of infundibulum with calyx exclusion were performed.

Retroperitoneal Leiomyoma. Transperitoneal Laparoscopic Surgery

70-year-old woman with retroperitoneal mass lesion undergoing laparoscopic resection of the tumor.

The histological analysis revealed a leiomyoma, with positive immunostaging for estrogenic receptors.

The differential diagnosis is a key element: the pathologist should be able to recognize this type of lesion and to differentiate it from a retroperitoneal leiomyosarcoma.

[Multiple metachronous metastasis of adenocarcinoma of the kidneys in crossed ectopy with fusion]

The A.A. report the clinic history of patient that showed up their examination with multiple metachronous arose fifteen months ago after a widening nephrectomy, by adenocarcinoma of ectopic-crossed kidney with fusion. They resume the pathogenetic and therapeutics hypothesis; in agreement on the prognostic difficulty and on the variability line of conduct by the kidney adenocarcinoma.

Concentrations of 24,25-dihydroxyvitamin D and 25-hydroxyvitamin D in paired maternal-cord sera

Mean serum concentrations of 24,25-dihydroxyvitamin D (24,25(OH)2D) and 25-hydroxyvitamin D (25OHD), measured by competitive radioassays, were significantly higher in maternal serum than in cord serum of term infants in both black and white subjects. There were positive correlations between maternal and cord levels of both metabolites of vitamin D. Serum concentrations of 24,25(OH)2D and 25OHD were significantly lower in white pregnant subjects than in nonpregnant women. In utero levels of 24,25(OH)2D and 25OHD probably reflect maternal stores of these metabolites.

Prostaglandins and gastrointestinal function

Much work has been done and much remains to be done in defining the role of the prostaglandins in the physiology and pathophysiology of the gastrointestinal tract. The following statements summarize the current knowledge of the prostaglandins in human gastrointestinal function: 1. Prostaglandins of the E type have been isolated from human gastrointestinal tissue. They are naturally occurring 20 carbon hydroxy fatty acids synthesized and degraded in the same intestinal tissue by a 15-prostaglandin dehydrogenase. 2. Prostaglandins E2 and PGF2alpha have opposing, dose-related effects on the lower esophageal sphincter and lower two thirds of the esophagus. Sphincter pressure is decreased and esophageal contractions are inhibited by PGE2, whereas sphincter pressure is increased and esophageal contractions are induced by PGF2alpha. 3. Basal and stimulated gastric acid secretion is inhibited by PGE and its methyl analogues, but not by PGF, in a dose-related, nonselective manner. Oral administration of PGE methyl analogues may be an effective mode of therapy in peptic ulcer disease. 4. The prostaglandins reduce absorption and induce secretion of electrolytes and water in the jejunum and ileum but not in the colon. This secretory effect has been implicated in certain pathologic conditions. 5. The prostaglandins appear to be vasodilators of the hepatic circulation. Prostaglandin E contracts the gall bladder, relaxes the sphincter of Oddi and inhibits isosmotic fluid transport. 6. Pancreatic secretion and insulin release are inhibited by the prostaglandins in vivo and secretion is stimulated in vitro. The actual role of the prostaglandins in insulin release is not known.