Effects of (poly)phenols on circadian clock gene-mediated metabolic homeostasis in cultured mammalian cells: a scoping review

Metabolic homeostasis is regulated by circadian clocks. Disruption to our circadian clocks, by lifestyle behaviors such as timing of eating and sleeping, has been linked to increased rates of metabolic disorders. There is now considerable evidence that selected dietary (poly)phenols, including flavonoids, phenolic acids and tannins, may modulate both metabolic and circadian processes. This review evaluates the effects of (poly)phenols on circadian clock genes and linked metabolic homeostasis in vitro, and potential mechanisms of action, by critically evaluating the literature on mammalian cells. A systematic search was conducted to ensure full coverage of the literature, and identified 43 relevant studies addressing the effects of (poly)phenols on cellular circadian processes. Nobiletin and tangeretin, found in citrus, (-)-epigallocatechin-3-gallate from green tea, urolithin A, a gut microbial metabolite from ellagitannins in fruit, curcumin, bavachalcone, cinnamic acid and resveratrol at low micromolar concentrations all affect circadian molecular processes in multiple types of synchronized cells. Nobiletin emerges as a putative Retinoic acid-related Orphan Receptor (RORα/γ) agonist, leading to induction of the circadian regulator Brain and Muscle ARNT-Like 1 (BMAL1), and increased Period Circadian Regulator 2 (PER2) amplitude and period. These effects are clear despite substantial variations in the protocols employed, and this review suggests a methodological framework to help future study design in this emerging area of research.

Flavonoids and phenolic acids from sugarcane: Distribution in the plant, changes during processing, and potential benefits to industry and health

Sugarcane (Saccharum sp.) plants are grown in warmer climates throughout the world and processed to produce sugar as well as other useful byproducts such as molasses and bagasse. Sugarcane is rich in (poly)phenols, but there has been no attempt to critically evaluate the published information based on the use of suitable methodologies. The objective of this review is to evaluate the quantitative and qualitative (poly)phenolic profiles of individual parts of the sugarcane plant and its multiple industrial products, which will help develop new processes and uses for sugarcane (poly)phenols. The quantitative analysis involves the examination of extraction, concentration, and analytical techniques used in each study for each plant part and product. The qualitative analysis indicates the identification of various (poly)phenols throughout the sugarcane processing chain, using only compounds elucidated through robust analytical methodologies such as mass spectrometry or nuclear magnetic resonance. In conclusion, sugarcane (poly)phenols are predominantly flavonoids and phenolic acids. The main flavonoids, derivatives of apigenin, luteolin, and tricin, with a substantial proportion of C-glycosides, are consistently found across all phases of sugarcane processing. The principal phenolic acids reported throughout the process include chlorogenic acids, as well as ferulic and caffeic acids mostly observed after hydrolysis. The derivation of precise quantitative information across publications is impeded by inconsistencies in analytical methodologies. The presence of multiple (poly)phenols with potential benefits for industrial applications and for health suggests sugarcane could be a useful provider of valuable compounds for future use in research and industrial processes.

Maternal selenium dietary supplementation alters sociability and reinforcement learning deficits induced by in utero exposure to maternal immune activation in mice

Maternal immune activation (MIA) during pregnancy increases the risk for the unborn foetus to develop neurodevelopmental conditions such as autism spectrum disorder and schizophrenia later in life. MIA mouse models recapitulate behavioural and biological phenotypes relevant to both conditions, and are valuable models to test novel treatment approaches. Selenium (Se) has potent anti-inflammatory properties suggesting it may be an effective prophylactic treatment against MIA. The aim of this study was to determine if Se supplementation during pregnancy can prevent adverse effects of MIA on offspring brain and behaviour in a mouse model. Selenium was administered via drinking water (1.5 ppm) to pregnant dams from gestational day (GD) 9 to birth, and MIA was induced at GD17 using polyinosinic:polycytidylic acid (poly-I:C, 20 mg/kg via intraperitoneal injection). Foetal placenta and brain cytokine levels were assessed using a Luminex assay and brain elemental nutrients assessed using inductively coupled plasma- mass spectrometry. Adult offspring were behaviourally assessed using a reinforcement learning paradigm, the three-chamber sociability test and the open field test. MIA elevated placental IL-1β and IL-17, and Se supplementation successfully prevented this elevation. MIA caused an increase in foetal brain calcium, which was prevented by Se supplement. MIA caused in offspring a female-specific reduction in sociability, which was recovered by Se, and a male-specific reduction in social memory, which was not recovered by Se. Exposure to poly-I:C or selenium, but not both, reduced performance in the reinforcement learning task. Computational modelling indicated that this was predominantly due to increased exploratory behaviour, rather than reduced rate of learning the location of the food reward. This study demonstrates that while Se may be beneficial in ameliorating sociability deficits caused by MIA, it may have negative effects in other behavioural domains. Caution in the use of Se supplementation during pregnancy is therefore warranted.

Plasma measurements of the dual sugar test reveal carbohydrate immediately alleviates intestinal permeability caused by exertional heat stress

The aim of this set of randomised cross-over studies was to determine the impact of progressive heat exposure and carbohydrate or protein feeding during exertional stress on small intestine permeability using a dual sugar test. In our previous work, and typically in the field, recovery of lactulose and l-rhamnose is measured cumulatively in urine. This follow-up study exploits our novel high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) protocol to accurately quantify the sugars in plasma. Endurance-trained participants completed experimental trial A (ET-A; n = 8), consisting of 2 h running at 60%V ̇ O 2 max ${\dot V_{{{\mathrm{O}}_{\mathrm{2}}}{\mathrm{max}}}}$ in temperate, warm and hot ambient conditions, and/or experimental trial B (ET-B; n = 9), consisting of 2 h running at 60%V ̇ O 2 max ${\dot V_{{{\mathrm{O}}_{\mathrm{2}}}{\mathrm{max}}}}$ in the heat while consuming water, carbohydrate or protein. Blood samples were collected and plasma lactulose (L) and l-rhamnose (R) appearance, after dual sugar solution ingestion at 90 min of exercise, was quantified by HPAEC-PAD to measure plasma L/R and reveal new information about intestinal permeability immediately post-exercise and during recovery. In ET-A, plasma L/R increased immediately post-exercise in hot compared with temperate and warm conditions, while, in ET-B, carbohydrate alleviated this, and this information was otherwise missed when measuring urine L/R. Consuming carbohydrate or protein before and during exercise attenuated small intestine permeability throughout recovery from exertional heat stress. We recommend using the dual sugar test with quantification of plasma sugars by HPAEC-PAD at intervals to maximise intestinal permeability data collection in exercise gastroenterology research, as this gives additional information compared to urinary measurements. KEY POINTS: Intestinal permeability is typically assessed using a dual sugar test, by administering a drink containing non-metabolisable sugars (e.g. lactulose (L) and l-rhamnose (R)) that can enter the circulation by paracellular translocation when the epithelium is compromised, and are subsequently measured in urine. We demonstrate that our recently developed ion chromatography protocol can be used to accurately quantify the L/R ratio in plasma, and that measuring L/R in plasma collected at intervals during the post-exercise recovery period reveals novel acute response information compared to measuring 5-h cumulative urine L/R. We confirm that exercising in hot ambient conditions increases intestinal epithelial permeability immediately after exercise, while consuming carbohydrate or protein immediately before and during exercise attenuates this. We recommend using our dual sugar absorption test protocol to maximise intestinal epithelial permeability data collection in exercise gastroenterology research and beyond.

Optimization of 1,2,4-Triazole-Based p97 Inhibitors for the Treatment of Cancer

The AAA+ ATPase p97 (valosin-containing protein, VCP) is a master regulator of protein homeostasis and therefore represents a novel target for cancer therapy. Starting from a known allosteric inhibitor, NMS-873, we systematically optimized this scaffold, in particular, by applying a benzene-to-acetylene isosteric replacement strategy, specific incorporation of F, and eutomer/distomer identification, which led to compounds that exhibited nanomolar biochemical and cell-based potency. In cellular pharmacodynamic assays, robust effects on biomarkers of p97 inhibition and apoptosis, including increased levels of ubiquitinated proteins, CHOP and cleaved caspase 3, were observed. Compound (R)-29 (UPCDC-30766) represents the most potent allosteric inhibitor of p97 reported to date.

A systematic review of the inhibitory effect of extracts from edible parts of nuts on α-glucosidase activity

An elevated postprandial glycaemic response is a risk factor for developing type 2 diabetes mellitus (T2DM). Inhibition of digestive enzymes, including membrane-bound brush-border α-glucosidases, leads to slowed carbohydrate digestion and absorption, and reduced postprandial glycaemia. Nuts are eaten widely around the world, and have the potential to inhibit α-glucosidases through their content of polyphenols and other bioactive compounds. We set out to conduct a systematic literature review exploring the inhibitory effect of extracts from edible parts of various nuts on α-glucosidase activity in vitro to ensure, as far as possible, that no papers were missed. After an initial screening, 38 studies were reviewed in full, of which 15 were suitable for the present systematic review. Notably, no studies were found which tested the inhibitory potential of nut extracts against human α-glucosidases. Two studies showed that extracts from almonds and hazelnuts inhibited rat α-glucosidase activity, but the remaining papers reported data on the yeast α-glucosidase enzyme. Where yeast and rat enzymes can be compared, it is clear that nut extracts inhibit yeast α-glucosidase more strongly than mammalian α-glucosidase, which may lead to over-estimation when predicting effects in vivo when using data from the yeast enzyme. In contrast, acarbose is a stronger inhibitor of mammalian α-glucosidase compared to the yeast enzyme. Thus, although the present review indicates that extracts from nuts inhibit yeast α-glucosidase, this cannot be extrapolated to humans in vivo. There is some evidence that extracts from almonds and hazelnuts inhibit rat α-glucosidase, but no information on human enzyme sources. Since most work has been published on the yeast enzyme, future work in vitro must utilise mammalian, and preferably human, α-glucosidases in order to be relevant to human health and disease. This systematic review was registered at INPLASY as INPLASY202280061.

Measuring key human carbohydrate digestive enzyme activities using high-performance anion-exchange chromatography with pulsed amperometric detection

Carbohydrate digestion in the mammalian gastrointestinal tract is catalyzed by α-amylases and α-glucosidases to produce monosaccharides for absorption. Inhibition of these enzymes is the major activity of the drugs acarbose and miglitol, which are used to manage diabetes. Furthermore, delaying carbohydrate digestion via inhibition of α-amylases and α-glucosidases is an effective strategy to blunt blood glucose spikes, a major risk factor for developing metabolic diseases. Here, we present an in vitro protocol developed to accurately and specifically assess the activity of α-amylases and α-glucosidases, including sucrase, maltase and isomaltase. The assay is especially suitable for measuring inhibition by compounds, drugs and extracts, with minimal interference from impurities or endogenous components, because the substrates and digestive products in the enzyme activity assays are quantified directly by high-performance anion-exchange chromatography with pulsed amperometric detection (HPAE-PAD). Multiple enzyme sources can be used, but here we present the protocol using commercially available human α-amylase to assess starch hydrolysis with maltoheptaose as the substrate, and with brush border sucrase-isomaltase (with maltase, sucrase and isomaltase activities) derived from differentiated human intestinal Caco-2(/TC7) cells to assess hydrolysis of disaccharides. The wet-lab assay takes ~2-5 h depending on the number of samples, and the HPAE-PAD analysis takes 35 min per sample. A full dataset therefore takes 1-3 d and allows detection of subtle changes in enzyme activity with high sensitivity and reliability.

Flavonoids as Human Intestinal α-Glucosidase Inhibitors

Certain flavonoids can influence glucose metabolism by inhibiting enzymes involved in carbohydrate digestion and suppressing intestinal glucose absorption. In this study, four structurally-related flavonols (quercetin, kaempferol, quercetagetin and galangin) were evaluated individually for their ability to inhibit human α-glucosidases (sucrase, maltase and isomaltase), and were compared with the antidiabetic drug acarbose and the flavan-3-ol(−)-epigallocatechin-3-gallate (EGCG). Cell-free extracts from human intestinal Caco-2/TC7 cells were used as the enzyme source and products were quantified chromatographically with high accuracy, precision and sensitivity. Acarbose inhibited sucrase, maltase and isomaltase with IC₅₀ values of 1.65, 13.9 and 39.1 µM, respectively. A similar inhibition pattern, but with comparatively higher values, was observed with EGCG. Of the flavonols, quercetagetin was the strongest inhibitor of α-glucosidases, with inhibition constants approaching those of acarbose, followed by galangin and kaempferol, while the weakest were quercetin and EGCG. The varied inhibitory effects of flavonols against human α-glucosidases depend on their structures, the enzyme source and substrates employed. The flavonols were more effective than EGCG, but less so than acarbose, and so may be useful in regulating sugar digestion and postprandial glycaemia without the side effects associated with acarbose treatment.

The Ability of Quercetin and Ferulic Acid to Lower Stored Fat is Dependent on the Metabolic Background of Human Adipocytes

SCOPE

Dietary flavonoids and phenolic acids can modulate lipid metabolism, but effects on mature human adipocytes are not well characterized.

MATERIALS AND METHODS

Human adipocytes are differentiated, and contain accumulated lipids, mimicking white adipocytes. They are then cultured either under conditions of actively synthesizing and accumulating additional lipids through lipogenesis ("ongoing lipogenic state") or under conditions of maintaining but not increasing stored lipids ("lipid storage state"). Total lipid, lipidomic and transcriptomics analyses are employed to assess changes after treatment with quercetin and/or ferulic acid.

RESULTS

In the "lipid storage state," a longer-term treatment (3 doses over 72 h) with low concentrations of quercetin and ferulic acid together significantly lowered stored lipid content, modified lipid composition, and modulated genes related to lipid metabolism with a strong implication of peroxisome proliferator-activated receptor (PPARα)/retinoid X receptor (RXRα) involvement. In the "ongoing lipogenic state," the effect of quercetin and ferulic acid is markedly different, with fewer changes in gene expression and lipid composition, and no detectable involvement of PPARα/RXRα, with a tenfold higher concentration required to attenuate stored lipid content.

CONCLUSIONS

Multiple low-dose treatment of quercetin and ferulic acid modulates lipid metabolism in adipocytes, but the effect is dramatically dependent on the metabolic state of the cell.

The effect of quercetin on endothelial cells is modified by heterocellular interactions

Single cell-type models are useful for determining mechanisms, but in vivo, cell-cell interactions are important, and neighbouring cells can impact endothelial cell function. Quercetin can attenuate endothelial dysfunction by modulating vascular tone and reducing inflammation. We determined the effect of quercetin on a co-culture between Human Umbilical Vein Endothelial Cells (HUVEC) and human HepG2 hepatic cells or human LHCN-M2 muscle cells. Heme oxygenase-1 (HO-1) mRNA and protein were decreased, pyruvate dehydrogenase kinase (PDK) 4 and glucose transporter (GLUT) 3 mRNA increased, and GLUT1 protein decreased in HUVEC when cultured with HepG2. GLUT transporters, but not the other targets, were similarly regulated in co-culture with muscle cells. Some but not all of the effects were mediated by lactate and transforming growth factor β1. Quercetin added apically to the endothelial cells upregulated HO-1 and downregulated PDK4 both in monoculture and in co-culture, but the total PDK4 levels were higher in the presence of HepG2 cells. In the absence of general permeability changes, glucose transport across the endothelial monolayer was elevated in the presence of HepG2 cells, however this effect was moderated by quercetin applied on the apical side of the endothelial cells. At lower glucose concentration, apical quercetin also promoted glucose uptake in HepG2 cells. Co-culturing HUVEC with the HepG2 cells showed capacity to modulate quercetin-elicited changes in endothelial gene transcription and glucose transport.

Quercetin preserves redox status and stimulates mitochondrial function in metabolically-stressed HepG2 cells

Hyperglycemia augments formation of intracellular reactive oxygen species (ROS) with associated mitochondrial damage and increased risk of insulin resistance in type 2 diabetes. We examined whether quercetin could reverse chronic high glucose-induced oxidative stress and mitochondrial dysfunction. Following long-term high glucose treatment, complex I activity was significantly decreased in isolated mitochondria from HepG2 cells. Quercetin dose-dependently recovered complex I activity and lowered cellular ROS generation under both high and normal glucose conditions. Respirometry studies showed that quercetin could counteract the detrimental increase in inner mitochondrial membrane proton leakage resulting from high glucose while it increased oxidative respiration, despite a decrease in electron transfer system (ETS) capacity, and lower non-ETS oxygen consumption. A quercetin-stimulated increase in cellular NAD⁺/NADH was evident within 2 h and a two-fold increase in PGC-1α mRNA within 6 h, in both normal and high glucose conditions. A similar pattern was also found for the mRNA expression of the repulsive guidance molecule b (RGMB) and its long non-coding RNA (lncRNA) RGMB-AS1 with quercetin, indicating a potential change of the glycolytic phenotype and suppression of aberrant cellular growth which is characteristic of the HepG2 cells. Direct effects of quercetin on PGC-1α activity were minimal, as quercetin only weakly enhanced PGC-1α binding to PPARα in vitro at higher concentrations. Our results suggest that quercetin may protect mitochondrial function from high glucose-induced stress by increasing cellular NAD⁺/NADH and activation of PGC-1α-mediated pathways. Lower ROS in combination with improved complex I activity and ETS coupling efficiency under conditions of amplified oxidative stress could reinforce mitochondrial integrity and improve redox status, beneficial in certain metabolic diseases.

Gut microbiome catabolites as novel modulators of muscle cell glucose metabolism

The gut microbiome supplies essential metabolites such as short-chain fatty acids to skeletal muscle mitochondria, and the composition and activity of the microbiota is in turn affected by muscle fitness. To further our understanding of the complex interactions between the gut microbiome and muscle, we examined the effect of microbiota-derived phenolic metabolites on the ability of human muscle cells to take up and metabolize glucose. As a model, we used the differentiated human skeletal muscle myoblast line, LHCN-M2, which expresses typical muscle phenotypic markers. We initially tested a selected panel of parent phenolic compounds and microbial metabolites, and their respective phenolic conjugates, as found in blood. Several of the tested compounds increased glucose uptake and metabolism, notably in high glucose- and insulin-treated myotubes. One of the most effective was isovanillic acid 3 -O-sulfate (IVAS), a metabolite from the microbiome found in the blood, primarily derived from consumed cyanidin 3 -O-glucoside, a major compound in berry fruits. IVAS stimulated a dose-dependent increase in glucose transport through glucose transporter GLUT4- and PI3K-dependent mechanisms. IVAS also up-regulated GLUT1, GLUT4, and PI3K p85α protein, and increased phosphorylation of Akt. The stimulation of glucose uptake and metabolism by a unique microbiome metabolite provides a novel link among diet, gut microbiota, and skeletal muscle energy source utilization.-Houghton, M. J., Kerimi, A., Mouly, V., Tumova, S., Williamson, G. Gut microbiome catabolites as novel modulators of muscle cell glucose metabolism.

Lithium Enolates Derived from Weinreb Amides: Insights into Five-Membered Chelate Rings

Enolization of O-methyl hydroxamic acids (Weinreb amides) in tetrahydrofuran solution with lithium diisopropylamide affords predominantly tetrameric enolates. Aryl substituents on the enolates promote deaggregation. The aggregation states are assigned by using the method of continuous variation in conjunction with 6Li NMR spectroscopy. Decoalescence of the tetramer resonance below -100 °C shows considerable spectral complexity attributed to isomerism of the methoxy-based chelates. Density functional theory calculations were used to examine the consequences of the bite angle of five-membered chelates in cubic tetramers and resulting solvation numbers that were higher than anticipated.

Lithium Enolates Derived from Pyroglutaminol: Mechanism and Stereoselectivity of an Azaaldol Addition

A lithium enolate derived from an acetonide-protected pyroglutaminol undergoes a highly selective azaaldol addition with (E)-N-phenyl-1-[2-(trifluoromethyl)phenyl]methanimine. The selectivity is sensitive to tetrahydrofuran (THF) concentration, temperature, and the presence of excess lithium diisopropylamide base. Rate studies show that the observable tetrasolvated dimeric enolate undergoes reversible deaggregation, with the reaction proceeding via a disolvated-monomer-based transition structure. Limited stereochemical erosion stems from the intervention of a trisolvated-monomer-based pathway, which is suppressed at low THF concentrations and elevated temperature. Endofacial selectivity observed with excess lithium diisopropylamide (LDA) is traced to an intermediate dianion formed by subsequent lithiation of the monomeric azaaldol adduct, which is characterized as both a dilithio form and a trilithio dianion-LDA mixed aggregate.

Lithium Enolates Derived from Pyroglutaminol: Aggregation, Solvation, and Atropisomerism

Lithium enolates derived from protected pyroglutaminols were characterized by using (6)Li, (13)C, and (19)F NMR spectroscopies in conjunction with the method of continuous variations. Mixtures of tetrasolvated dimers and tetrasolvated tetramers in different proportions depend on the steric demands of the hemiaminal protecting group, tetrahydrofuran concentration, and the presence or absence of an α-fluoro moiety. The high steric demands of the substituted bicyclo[3.3.0] ring system promote dimers to an unusual extent and allow solvents and atropisomers in cubic tetramers to be observed in the slow-exchange limit. Pyridine used as a (6)Li chemical shift reagent proved useful in assigning solvation numbers.

Changes in the innervation of the mouse internal anal sphincter during aging

BACKGROUND

The innervation of the mouse internal anal sphincter (IAS) has been little studied, and how it changes during aging has not previously been investigated. The aim of this study was therefore to characterize the distribution and density of subtypes of nerve fibers in the IAS and underlying mucosa in 3-, 12- to 13-, 18- and 24- to 25-month-old male C57BL/6 mice.

METHODS

Nerve fibers were immunolabeled with antibodies against protein gene product 9.5 (PGP9.5), neuronal nitric oxide synthase (nNOS), vasoactive intestinal polypeptide (VIP), substance P (SP), calcitonin gene-related peptide (CGRP), and calretinin (CR). Immunoreactivity in nerve fibers in the circular muscle and mucosa was quantified using Image J software.

KEY RESULTS

In young adult (3 month) mice, nNOS-immunoreactive (IR) nerve fibers were densely distributed in the circular muscle, but relatively few in the mucosa; VIP-IR nerve fibers were abundant in the circular muscle and common in the mucosa; SP-IR nerve fibers were common in circular muscle and mucosa; CGRP- and CR-IR nerve fibers were dense in mucosa and sparse in circular muscle. The density of PGP9.5 immunoreactivity (IRY) was not significantly reduced with age, but a significant reduction in nNOS-IRY and SP-IRY with age was found in the IAS circular muscle. Neuronal nitric oxide synthase-, VIP-, and SP-IRY in the anal mucosa were significantly reduced with age. CGRP-IRY in both circular muscle and mucosa was increased in 18-month-old animals.

CONCLUSIONS & INFERENCES

The density of immunoreactivity of markers for some types of IAS nerve fibers decreases during aging, which may contribute to age-related ano-rectal dysfunction.

Talocalcaneal and subfibular impingement in symptomatic flatfoot in adults

BACKGROUND

Patients with symptomatic flatfoot deformity often present with pain in the lateral part of the hindfoot. The cause of this pain has not been clearly established. Impingement between the talus and the calcaneus or between the calcaneus and the fibula has been suggested as a cause but has not been documented.

METHODS

We examined the computed tomographic scans, performed with simulated weight-bearing, of nineteen adult patients with symptomatic flatfoot to determine the potential causes of pain in the lateral aspect of the foot. The scans were performed with use of a custom loading frame designed to simulate weight-bearing with the foot in a neutral position while a 75-N axial compressive load was applied. Four examiners independently examined the coronal images as well as sagittal plane reconstructions for direct (bone-on-bone contact) and indirect (subchondral sclerosis or cysts) evidence of (1) extra-articular contact between the talus and the calcaneus in the sinus tarsi and (2) contact between the calcaneus and the fibula. The data were compared with those from five scans of normal feet in neutral alignment.

RESULTS

Overall, the prevalence of sinus tarsi impingement was 92% and the prevalence of calcaneofibular impingement was 66% in the flatfoot group versus 0% and 5%, respectively, in the control group. The study patients who had calcaneofibular impingement also had sinus tarsi impingement. There was substantial agreement among the examiners as to whether impingement was present.

CONCLUSIONS

There appear to be two frequently occurring extra-articular sources of bone impingement in the lateral aspect of the hindfoot in adults with symptomatic severe flatfoot deformity. The impingement in the lateral aspect of the hindfoot may first occur within the sinus tarsi and then involve the calcaneofibular region. Cyst formation and/or sclerosis in this region that is visible on plain radiographs or on computed tomographic scans performed without weight-bearing should create suspicion of impingement.

Osteoma of the innominate bone with intraosseous and parosteal involvement

A case has been presented of a 47-year-old woman with a dense bony mass both within and on the surface of her right public ramus. This was discovered incidentally on plain radiographs of the pelvis. Besides osteoma, a differential diagnosis of parosteal osteosarcoma, ossifying parosteal lipoma, periostitis ossificans, osteochondroma with attenuated cartilage cap, and melorheostosis was considered. Histological evaluation of open biopsy samples showed typical findings of an osteoma. This is an unusual case of an osteoma with both parosteal and intraosseous involvement.

Pulmonary hypoplasia in mice homozygous for the cartilage matrix deficiency (cmd) gene: a model for human congenital disorder

As a potential model for the study of pulmonary hypoplasia in the lethal chondrodystrophies in man, lungs of day 18 mouse fetuses homozygous for cartilage matrix deficiency (cmd) were studied by biochemical, histological, and morphometric techniques. Wet and dry mutant lung weights were 30% less than corresponding normal lung weights. Total DNA and protein contents per whole mutant lung were decreased by 23% and 29%, respectively. An increased number of smaller-than-normal primary saccules were observed in histological sections of mutant lungs, which correspond to the difference in lung wet weight. The thoracic volume of mutants was decreased by an average of 38%. Amniotic fluid volume measurements indicated polyhydramnios in the mutant. The smaller-than-normal thoracic cavity observed in the cmd mutant, imposing a significant restriction on the developing lungs, is the most likely mechanism of pulmonary hypoplasia in this form of chondrodystrophy-confirming that reported for the cho mouse mutant.

Pulmonary hypoplasia in chondrodystrophic mice

Lungs of day-18 fetal mice with hereditary chondrodysplasia (cho) were examined histologically and biochemically for pulmonary hypoplasia. Compared with normal littermate controls, the mutant's lungs were smaller by 37 (wet weight) and 22% (dry weight). Total DNA and protein per whole lung were decreased by 13 and 19%, respectively. The significantly smaller-than-normal terminal sacs observed in histological sections of the mutant's lungs corresponded with the greater difference (37%) in lung wet weight. The developmental mechanism for this disorder was further explored by examining the volumes of thoracic cavity and amniotic fluid. The volume of the thoracic cavity of newborn mutants was less than half that of controls, suggesting that the pathogenetic mechanism for the hypoplastic lungs in chondrodysplastic mice includes thoracic dystrophy. Measurement of the amniotic fluid volume revealed polyhydramnios in the mutant, thereby ruling out oligohydramnios as a mechanism. The relevance of this study to human pulmonary hypoplasia in short-limb chondrodystrophy is discussed.