Impact of Data Presentation on Physician Performance Utilizing Artificial Intelligence-Based Computer-Aided Diagnosis and Decision Support Systems

Ultrasound (US) is a valuable imaging modality used to detect primary breast malignancy. However, radiologists have a limited ability to distinguish between benign and malignant lesions on US, leading to false-positive and false-negative results, which limit the positive predictive value of lesions sent for biopsy (PPV3) and specificity. A recent study demonstrated that incorporating an AI-based decision support (DS) system into US image analysis could help improve US diagnostic performance. While the DS system is promising, its efficacy in terms of its impact also needs to be measured when integrated into existing clinical workflows. The current study evaluates workflow schemas for DS integration and its impact on diagnostic accuracy. The impact on two different reading methodologies, sequential and independent, was assessed. This study demonstrates significant accuracy differences between the two workflow schemas as measured by area under the receiver operating curve (AUC), as well as inter-operator variability differences as measured by Kendall’s tau-b. This evaluation has practical implications on the utilization of such technologies in diagnostic environments as compared to previous studies.

Characterization of on-target adverse events caused by TRK inhibitor therapy

BACKGROUND

The tropomyosin receptor kinase (TRK) pathway controls appetite, balance, and pain sensitivity. While these functions are reflected in the on-target adverse events (AEs) observed with TRK inhibition, these AEs remain under-recognized, and pain upon drug withdrawal has not previously been reported. As TRK inhibitors are approved by multiple regulatory agencies for TRK or ROS1 fusion-positive cancers, characterizing these AEs and corresponding management strategies is crucial.

PATIENTS AND METHODS

Patients with advanced or unresectable solid tumors treated with a TRK inhibitor were retrospectively identified in a search of clinical databases. Among these patients, the frequency, severity, duration, and management outcomes of AEs including weight gain, dizziness or ataxia, and withdrawal pain were characterized.

RESULTS

Ninety-six patients with 15 unique cancer histologies treated with a TRK inhibitor were identified. Weight gain was observed in 53% [95% confidence interval (CI), 43%-62%] of patients and increased with time on TRK inhibition. Pharmacologic intervention, most commonly with glucagon-like peptide 1 analogs or metformin, appeared to result in stabilization or loss of weight. Dizziness, with or without ataxia, was observed in 41% (95% CI, 31%-51%) of patients with a median time to onset of 2 weeks (range, 3 days to 16 months). TRK inhibitor dose reduction was the most effective intervention for dizziness. Pain upon temporary or permanent TRK inhibitor discontinuation was observed in 35% (95% CI, 24%-46%) of patients; this was more common with longer TRK inhibitor use. TRK inhibitor reinitiation was the most effective intervention for withdrawal pain.

CONCLUSIONS

TRK inhibition-related AEs including weight gain, dizziness, and withdrawal pain occur in a substantial proportion of patients receiving TRK inhibitors. This safety profile is unique relative to other anticancer therapies and warrants careful monitoring. These on-target toxicities are manageable with pharmacologic intervention and dose modification.

Presence of peroxisomal membrane proteins in liver and fibroblasts from patients with the Zellweger syndrome and related disorders: evidence for the existence of peroxisomal ghosts

The presence and intracellular localization of peroxisomal integral membrane proteins (PMP) were investigated in liver and cultured skin fibroblasts from control subjects and patients with the Zellweger syndrome and related disorders in which peroxisomes are virtually absent. Immunoblotting experiments showed that 22, 36 and 69 kDa PMPs were present and were confined to the membranous fraction both in the control liver and in the livers from the Zellweger patients. The 22 and 36 kDa PMPs were present in significantly lower amounts in the patients' livers than in the control liver. A reduced amount of the 69 kDa PMP was found in liver from one Zellweger but not in liver from another. The subcellular localization in fibroblasts of catalase and the 69 kDa PMP was studied by indirect immunofluorescence. A characteristic punctate fluorescence was seen in control cells incubated with either anti-(catalase) or with anti-(69 kDa PMP). Incubation of mutant cells with anti-(catalase) resulted in a diffuse fluorescence, whereas with anti-(69 kDa PMP) fluorescent particles were visualized which, in some cell lines, were larger and fewer in number than in control cells. Cryosections of control and mutant cells were examined by electron microscopy using immunogold labeling. Control cells contained small structures consisting of a single membrane enclosing a homogeneous matrix; the membranes reacted with anti-(69 kDa PMP) and the matrix with anti-(catalase). The mutant cell lines contained spherical or ellipsoidal structures whose membranes reacted with anti-(69 kDa PMP); no labeling was observed with anti-(catalase). We conclude that peroxisomal ghosts, the membranes of which contain the 69 kDa PMP, are present in peroxisome-deficient cell lines from all complementation groups studied so far.

Freiberg's infraction of the second metatarsal head with formation of multiple loose bodies

Freiberg's infraction is an osteonecrotic disease process that most often involves the head of the second metatarsal. Establishing a diagnosis can be difficult early in the disease course, mimicking such pathologic processes as stress fracture, septic joint infection, tumors, metatarsalgia, various arthritic diseases, etc. A review of the literature reveals many treatment options and many theories of its etiology. The clinical signs and symptoms, review of the etiologies, radiographic presentation, and conservative and surgical treatments of this disease are presented. A case history and treatment summary of a patient afflicted with Freiberg's infarction involving the second metatarsophalangeal joint of the right foot is presented. Treatment consisted of evacuation of multiple loose bodies from the joint, resection arthroplasty of the diseased joint, and insertion of a total joint prosthesis.

CONTROL OF ANTHOCYANIN SYNTHESIS IN PETUNIA HYBRIDA BY MULTIPLE ALLELIC SERIES OF THE GENES An1 AND An2

A mutable allele of the An1 locus in Petunia hybrida has given rise to a multiple series of stable derivative alleles. Anthocyanin concentration in mature flowers of these mutants (an1  +/p/an1) decreases from the wild-type red to the recessive white in a continuous series. Anthocyanin composition changes regularly: the ratio of peonidin to cyanidin is 3.5 for an an1  +/+/an1 and 1.2 for an an1  +/p5/an1 mutant. Analysis of anthocyanins during flower development indicates that these differences in composition are due to the specific state of the An1 locus and not to anthocyanin concentration. Anthocyanin concentration in flowers of the allelic series for An1 correlates with the activity of the enzymes UDP-glucose: flavonoid-3-O-glucosyltransferase and SAM: anthocyanin-3′-O-methyltransferase. The same correlations were found for members of a comparable allelic series at the An2 locus. The possibility that the correlation between the enzyme activities is due to the occurrence of a multienzyme complex is discussed.

Incorporation of [3H]Uridine and [3H]Thymidine During the Phase of Nucleolar Multiplication in Xenopus Laevis Oögenesis: A High-Resolution Autoradiographic Study

The nucleoli of the premeiotic, pachytene and young diplotene (A, B, C, up to 100µm diameter) oocytes are heavily labelled after 7 h of [3H]uridine incorporation, which is in good agreement with the hypothesis that nucleolar multiplication occurs throughout all these early stages of oogenesis. The total labelling of the nucleolar, nuclear and cytoplasmic volumes has been calculated from the uridine high-resolution autoradiograms and the estimated amounts are discussed. The chromatin of several premeiotic oocytes and the cap of all the pachytene oocytes are strongly labelled after 7 h of [3H]thymidine incorporation. We did not find any thymidine incorporation in the young A, B or C diplotene oocytes.

Evolution of the Nucleoli During Oogenesis in Xenopus Laevis Studied by Electron Microscopy

Xenopus laevis tadpoles and toads were killed at several ages. The structure of the nuclei of the germinal cells has been observed by light and electron microscopes. We distinguish 11 successive stages in nucleolar structure: (1) a single, essentially granular nucleolus in the oogonium (10 µm diameter), (2) a reticulated nucleolus in the leptotene oocyte, (3) fragmentation of this nucleolus into a few smaller nucleoli, (4) multiple tiny nucleoli appearing in the cap of the pachytene oocyte, (5) enrichment in the fibrillar constituent of these intra-cap nucleoli, (6) grouped spherical nucleoli, with well segregated granular and fibrillar constituents, as the disintegration of the cap is going on (diplotene A oocyte, 30 µm diameter), (7) dispersion of those nucleoli in the nuclear sap (diplotene B oocyte, 50 µm diameter), (8) formation of long, ribboned nucleoli with multiple DNA-rich spots (diplotene C oocyte, 100 µm diameter), (9) fragmentation of the nucleolar ribbons into multiple spherical nucleoli with excentric fibrillar core and granular cortex (diplotene D oocyte, 150 µm diameter), (10) multiple purely fibrillar nucleoli (diplotene E oocyte, between 150 and 400 µm diameter), and (11) multiple classical nucleoli with concentric fibrillar core and granular cortex (diplotene F oocyte, between 400 and 1000 µm diameter).

The multiplication of the nucleoli in Xenopus laevis may occur successively (a) by the fragmentation of the single oogonium nucleolus at the leptotene stage, (b) by de novo formation of nucleolar bodies inside the cap at the pachytene stage, and (c) by the growth of those nucleoli lying free in the nucleolar sap at the early diplotene stage. They evolve into nucleolar ribbons which later on fragment into spherical bodies.

Four successive phases during the growth of an oocyte can be distinguished with respect to the ribosomal system. (I) The first phase is characterized by the nucleolar DNA amplification. (II) During the second phase, the multiplication of the nucleoli is going on. Ribosomes are present in the cytoplasm and the rate of cellular growth is very high. (III) During the third phase, the synthesis of rRNAs seem to be repressed while the synthesis of heterogenous small RNAs is going on. Ribosomes are no longer visible in the cytoplasm. The nucleoli are purely fibrillar. The rate of cell growth is lower than in the preceding phase. (IV) During the fourth ( = Duryee lampbrush stages 3-6), or vitellogenic phase, rRNAs are actively synthesized and numerous ribosomes appear in the cytoplasm. The nucleoli have the classical structure and the rate of growth is about the same as during phase III.

Etude des ribosomes et du glycogène des gastrules de Xenopus laevis par cytochimie ultrastructurale

Les travaux de J. Brachet et de ses collaborateurs sur le rôle des acides nucléiques dans le développement embryonnaire des Amphibiens ont eu pour hypothèses directrices, ces dernières années (Brachet, 1965, 1967 a, b, 1968), que les synthèses protéiniques spécifiques des différentes étapes de la morphogénèse se feraient dans le cytoplasme au niveau des polyribosomes. Les RNA messagers de ces organites existeraient dans l'œuf sous des formes stables qui se démasqueraient au moment de la maturation et assureraient les synthèses protéiniques pendant la segmentation; à partir de la gastrulation, ils seraient synthétisés au contact de DNA chromosomiaux déréprimés de façon différentielle par les territoires cytoplasmiques où ils se trouvent. Au gradient ribosomial animal-végétatif de l'œuf indivis se superposerait ainsi dans les gastrules un gradient polysomial dorso-ventral, ce double gradient étant l'équivalent biochimique des gradients morphogénétiques des embryologistes. Cette conception s'appuie actuellement sur un très grand nombre d'expériences faites à l'aide de techniques biochimiques et autoradiographiques (Brachet, 1967b).

Ultrastructure et cytochimie ultrastructurale de la vésicule germinative et du cytoplasme périnucléaire de l'oocyte mûr de Xenopus laevis

Les oocytes et les œufs de Batraciens constituent, depuis longtemps, un matérial de choix pour les embryologistes. Au cours de ces dernières années, les phénomènes initiaux du développement embryonnaire ont été étudiés avec toute la précision que permettent les techniques biochimiques et cytochimiques actuelles. En particulier, l'étude de la maturation des oocytes de Batraciens a été reprise par plusieurs auteurs depuis que ce phénomène peut être obtenu in vitro (Dettlaff, Nikitina & Stroeva, 1964; Dettlaff, 1966; Brachet, 1965 a, b, 1967; Smith, Ecker & Subtelny, 1966). Brachet a mis en évidence l'apparition, au cours de la maturation, de grains Feulgen-positifs distincts des chromosomes, dans le sue nucléaire de Rana, de Xenopus et de Bufo ainsi que dans le cytoplasme périnucléaire des oocytes de Bufo. Ces grains se rassemblent dans le cytoplasme cortical, puis ils disparaissent (Brachet, 1965 a).

Laurence-Moon-Bardet-Biedl syndrome and polydactyly

Lawrence-Moon-Bardet-Biedl Syndrome (LMBBS) is a rare disorder that presents most commonly with five cardinal features including polydactyly. A review of LMBBS and a case report is presented. The practitioner should be aware that polydactyly may be one manifestation of a genetic syndrome.