The earliest events in BRAF-mutant colorectal cancer: exome sequencing of sessile serrated lesions with a tiny focus dysplasia or cancer reveals recurring mutations in two distinct progression pathways.

Around 15-30% of colorectal cancers (CRC) develop from sessile serrated lesions (SSLs). After many years of indolent growth, SSLs can develop dysplasia and rapidly progress to CRC through events that are only partially understood. We studied molecular events at the very early stages of progression of SSLs via the MLH1-proficient and deficient pathways to CRC. We collected a cohort of rare SSLs with a small focus (<10 mm) of dysplasia or cancer from the pathology archives of three hospitals. Whole-exome sequencing was performed on DNA from nonprogressed and progressed components of each SSL. Putative somatic driver mutations were identified in known cancer genes that were differentially mutated in the progressed component. All analyses were stratified by MLH1 proficiency. Forty-five lesions with a focus dysplasia or cancer were included, of which 22 (49%) were MLH1-deficient. Lesions had a median diameter of 10 mm (interquartile range [IQR] 8-15), while the progressed component had a median diameter of 3.5 mm (IQR 1.75-4.75). Tumor mutational burden (TMB) was high in MLH1-deficient lesions (23.9 mutations per MB) as compared to MLH1-proficient lesions (6.3 mutations per MB). We identified 34 recurrently mutated genes in MLH1-deficient lesions. Most prominently, ACVR2A and RNF43 were affected in 18/22 lesions, with mutations clustered in three hotspots. Most lesions with RNF43 mutations had concurrent mutations in ZNRF3. In MLH1-proficient lesions APC (10/23 lesions) and TP53 (6/23 lesions) were recurrently mutated. Our results show that the mutational burden is exceptionally high even in the earliest MLH1-deficient lesions. We demonstrate that hotspot mutations in ACVR2A and in the RNF43/ZNRF3 complex are extremely common in the early progression of SSLs along the MLH1-deficient serrated pathway, while APC and TP53 mutations are early events in the the MLH1-proficient pathway. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

[Cutaneous granulomatous reactions at botulinum neurotoxin A injection sites: First manifestation of systemic sarcoidosis]. / Granulomatöse Hautveränderungen an Botulinumtoxin-A-Injektionsstellen : Erstmanifestation einer systemischen Sarkoidose.

CASE REPORT: We report a case of granulomatous skin reaction after injection of an unknown botulinum neurotoxin (BoNT) A preparation. Four years after occurrence of skin lesions, systemic sarcoidosis became manifest. CONCLUSION: In addition to injection trauma, the BoNT A preparation may have acted as an immunogenic stimulus leading to cutaneous manifestation of sarcoidosis.

Assessment of vision-related quality of life in patients with central retinal artery occlusion.

BACKGROUND: Central retinal artery occlusion (CRAO) is a major cause for severe visual impairment. Its effect on vision-related quality of life has not yet been determined. The purpose of the present study was thus to assess vision-related quality of life in patients with CRAO using the 39-item National Eye Institute Visual Function Questionnaire. METHODS: The case-control study comprised 26 patients with unilateral CRAO and a control group consisting of 26 control subjects, matched for age and sex. Vision-related quality of life was measured using the 39-item National Eye Institute Visual Function Questionnaire. RESULTS: After Bonferroni correction, the median 39-item National Eye Institute Visual Function Questionnaire composite score was significantly lower in patients with CRAO than in those in the control group (P(corr) < 0.001). Patients with CRAO showed significantly lower median scores in 9 of 12 subscales: general vision (P(corr) < 0.001), peripheral vision (P(corr) < 0.001), difficulties with near-vision activities (P(corr) < 0.001), difficulties with distance-vision activities (P(corr) < 0.001), role difficulties as a result of vision problems (P(corr) < 0.001), dependency on others because of vision problems (P(corr) < 0.001), limitations in social functioning because of vision problems (P(corr) < 0.001), mental health symptoms because of vision problems (P(corr) < 0.001), and general health (P(corr) = 0.008). CONCLUSION: Our data suggest that vision-related quality of life is reduced in patients with CRAO.

Bioassay-guided investigation of the Tanzanian plant Pyrenacantha kaurabassana for potential anti-HIV-active compounds.

Two new anti-HIV xanthones, 6,7,11-trihydroxy-10-methoxy-9-(7-methoxy-3-methyl-1-oxoisochroman-5-yl)-2-methyl-12-oxo-12H-benzo[b]xanthene-4-carboxylic acid (1) and 6,7-dihydroxy-10,11-dimethoxy-9-(7-methoxy-3-methyl-1-oxoisochroman-5-yl)-2-methyl-12-oxo-12H-benzo[b]xanthene-4-carboxylic acid (2), and a new hexadecahydrochrysen-3-ol (3) were isolated from the tubers of Pyrenacantha kaurabassana. Compounds 1 and 2 showed moderate anti-HIV activity when tested in the deCIPhR assay on HIV virus type NL4-3, with IC50 values of 21 and 2 µg/mL, respectively.

A uterine leiomyoma in which a leiomyosarcoma with osteoclast-like giant cells and a metastasis of a ductal breast carcinoma are present.

Leiomyosarcoma of the uterus is a rare tumor, and the presence of osteoclast-like giant cells in this tumor is even rarer. A leiomyosarcoma arising in a leiomyoma is also quite unique. Breast cancer metastasizing to the uterus is seldom seen as well. A 70-year-old woman presented with metastasized breast cancer to the bones. An evaluation of the computed tomographic scan was made, which showed an enlarged uterus with a tumor. The tumor was a leiomyoma in which a leiomyosarcoma with osteoclast-like giant cells as well as a metastasis of a ductal breast carcinoma was present. To our knowledge, this is the first report of a leiomyosarcoma containing osteoclast-like giant cells, present in a leiomyoma, in a uterus also containing a ductal breast cancer metastasis present in the leiomyoma and myometrium.

Detection of a milk factor that facilitates folate uptake by intestinal cells.

Folate binding proteins in milk were tested for their effect on folate absorption. The uptake of bound folate by isolated mucosal cells from the rat small intestine was twice that of free folate and differed from it in being more effective with progression down the small intestine, in not being affected by glucose or Dilantin, in having a higher pH optimum, and in being affected by calcium concentration. This milk factor may enhance folate absorption in infants, whose risk of folate deficiency is high.

In vitro myelosuppression and immunosuppression by ethanol.

Concentrations of ethanol similar to those in the blood of intoxicated patients suppressed phytohemagglutinin- or streptolysin O-induced lymphocyte transformation, and inhibited bone marrow granulocyte colony growth in soft agar. Inhibition of lymphocyte transformation and granulocyte colony growth occurred despite the presence of large concentrations of folate and other vitamins. These in vitro findings may relate to in vivo effects of ethanol on myeloid and lymphoid tissue.

Malabsorption of hemoglobin iron in pernicious anemia: correction with intrinsic factor--containing substances.

Hemoglobin iron absorption in patients with treated prenicious anemia (PA) and concomitant iron deficiency was low compared to absorption in patients with iron deficiency alone. Crude and purified hog intrinsic factor (IF) concentrates doubled the absorption of hemoglobin iron in these patients as did normal (neutralized depepsinized) human gastric juice. Hemoglobin iron absorption was not significantly enhanced by PA gastric juice. Absorption of heme iron, like that of hemoglobin iron, was enhanced by normal neutralized depepsinized gastric juice. No enhancement of hemoglobin iron absorption by these substances was obtained in the normal or iron-deficient non-PA control subjects. Preincubation of the hog IF concentrate with antisera to IF significantly reduced the enhancement of hemoglobin iron absorption due to the concentrate. In vitro studies suggest that heme complexes with a substance present in IF-containing materials. Whether a gastric glycoprotein similar to IF serves as an intestinal transport factor for heme, similar to transport of vitamin B(12), or whether normal gastric juice acts by another mechanism cannot be determined at this time.

Defective DNA synthesis in human megaloblastic bone marrow: effects of homocysteine and methionine.

In B(12) deficiency, inadequate DNA synthesis seems due in large measure to a block of tetrahydrofolic acid (THFA) regeneration from 5-methyl THFA (via homocysteine transmethylation). In support of the above, homocysteine appears to facilitate and methionine to reduce de novo DNA synthesis. This was measured by the ability of deoxyuridine to suppress thymidine-(3)H uptake into DNA in human bone marrow cultures. The homocysteine effect in B(12)-deficient marrow supports the possibility that there is in man an additional B(12)-independent pathway for regeneration of THFA by methylation of homocysteine to form methionine. Among possible explanations for the methionine effect is end-product inhibition of the homocysteine transmethylase reaction, resulting in further accumulation of 5-methyl THFA. Homocysteine transmethylation may play an important role in the regulation of THFA availability and de novo DNA synthesis. In vitro and in vivo evidence suggests that methionine may be useful to potentiate and homocysteine to reduce methotrexate action.

Release of vitamin B12--binding protein by human leukocytes in vitro.

Human granulocytes (G) contain a vitamin B(12)-binding protein (B(12)BP). There is evidence that chronic myelogenous leukemia leukocytes (CMLL) may synthesize B(12)BP. Our prior studies suggested that intact, living intravascular G synthesize and release such protein into extracellular compartments in vivo. In the present study, CMLL were incubated in Trisbuffered Hank's basal salt solution (pH 7.2) containing 0.1% human serum albumin to study release of B(12)BP into the medium. B(12)BP was released continuously and in increasing amounts over a 5 hr period at 37 degrees C; this release was inhibited almost completely when the cells were incubated at 4 degrees C and by about half as much in the presence of N-ethylmaleimide (1 mmole/liter). Cycloheximide (50 mug/ml) had no effect on the release of B(12)BP but significantly inhibited incorporation of leucine-(3)H into leukocyte protein. G incubated with 20 mg/ml of compound 48/80, an experimental histamine-releasing agent, had a 6-fold increase in release of B(12)BP over a 2 hr period. Subcellular fractionation studies of human granulocytes demonstrate that most of the B(12)BP is associated with the granular (20,000 g) layer with an excellent correlation observed between its subcellular distribution and that of acid phosphatase.These findings suggest that the release of B(12)BP from G is mediated by an active process and provide further evidence that granulocytes are secretory as well as phagocytic cells.

Studies on derivation of transcobalamin 3 from granulocytes. Enhancement by lithium and elimination by fluoride of in vitro increments in vitamin B12-binding capacity.

Unsaturated vitamin B(12)-binding capacity (UBBC) of human serum is not reproducibly measurable because it increases variably in vitro in relation to time, temperature, and, in the case of plasma, anticoagulant present before removal of cells. This variable increase proved to be due to variable release in vitro of transcobalamin III (TC III) from granulocytes. UBBC increase was greatest (up to fourfold normal levels) in the presence of lithium, which is the heparin salt used in many laboratories doing UBBC studies. In vitro increase was least when blood was collected in EDTA at 0 degrees C and immediately centrifuges at 0 degrees C (T(0) sample); results equivalent to T(0) were obtained at room temperature even after several hours delay when 47 mM fluoride was present; either cold temperature or 47 mM fluoride appeared to prevent TC III release from granulocytes. The measured levels of the three transcobalamins with T(0) methods of collection, which presumably reflect most closely the in vivo circulating levels, suggest that TC I and TC III in normal plasms are of the same order of magnitude and together normally comprise less than 10% of the UBBC. Approximately 90% of the UBBC content of sonicates of peripheral blood granulocytes and of bone marrow aspirates of normal individuals appears to be TC III, with the rest being TC I. Thus, normal myelocytes, like normal granulocytes, appear to contain mainly TC III. No TC II was present in any of the sonicates. The general practice in most laboratories has been to determine serum UBBC. Because in vitro increments of up to 119% were found to occur in serum, this practice should be replaced by collection using methods that prevent such increments. Blood collected in EDTA-47 mM NaF had a stable, reproducible UBBC with no significant in vitro increment with time.EDTA-NaF UBBC was 640+/-168 (range 380-921 pg B(12) bound/ml plasma) for 12 normal adult men and 809+/-232 (range 505-1208) for normal adult women. It presumably approximates circulating UBBC and is substantially below the serum UBBC mean of 935+/-262 (range 611-1506 for the same 12 men) and 1273+/-355 (range 811-2306 for the same 10 women).

Long-term effects of rainforest disturbance on the nutrient composition of throughfall, organic layer percolate and soil solution at Mt. Kilimanjaro.

At the lower parts of the forest belt at Mt. Kilimanjaro, selective logging has led to a mosaic of mature forest, old secondary forests ( approximately 60 years), and old clearings ( approximately 10 years) covered by shrub vegetation. These variations in the vegetation are reflected by differences in nutrient leaching from the canopy and in both amount and quality of litter reaching the ground, thereby also influencing mineralization rates and the composition of seepage water in litter percolate and soil solution. The aim of this study was to investigate how above- and belowground nutrient dynamics vary between regeneration stages, and if forest regeneration at the clearings is hampered by a deterioration of abiotic site conditions. K, Mg, Ca, Na and N compounds were analysed in rainfall, throughfall, organic layer percolate and the soil solution to a depth of 1.00 m at three clearings, three secondary forest and four mature forest sites. Element fluxes via throughfall showed only small variations among regeneration stages except for K and NO(3)-N. With 57-83 kg ha(-1) a(-1)and 2.6-4.1 kg ha(-1) a(-1) respectively, K and NO(3)-N fluxes via throughfall were significantly higher at the clearings than at the mature forest sites (32-37 and 0.7-1.0 kg ha(-1) a(-1) for K and NO(3)-N). In organic layer percolate and in soil solution at 0.15-m soil depth, concentrations of K, Mg, Ca and N were highest at the clearings. In the organic layer percolate, median K concentrations were e.g. 7.4 mg l(-1) for the clearings but only 1.4 mg l(-1) for the mature forests, and for NO(3)-N, median concentrations were 3.1 mg l(-1) for the clearings but only 0.92 mg l(-1) for the mature forest sites. Still, differences in annual means between clearings and mature forests were not always significant due to a high variability within the clearings. With the exception of NO(3)-N, belowground nutrient concentrations in secondary forests ranged between concentrations in mature forests and clearings. Vegetation type-specific differences decreased with increasing soil depths in the soil solution. Overall, the opening of the forest led to a higher spatial and seasonal variation of nutrient concentrations in the seepage water. These results suggest differences in both mineralization rates and in nutrient budgeting at different regeneration stages. Since nutrient availability was highest at the clearings and no compaction of the soil was observed, deterioration of soil properties did not seem to be the main reason for the impeded regeneration on the clearings.

Key science questions from the second conference on early Mars: geologic, hydrologic, and climatic evolution and the implications for life.

In October 2004, more than 130 terrestrial and planetary scientists met in Jackson Hole, WY, to discuss early Mars. The first billion years of martian geologic history is of particular interest because it is a period during which the planet was most active, after which a less dynamic period ensued that extends to the present day. The early activity left a fascinating geological record, which we are only beginning to unravel through direct observation and modeling. In considering this time period, questions outnumber answers, and one of the purposes of the meeting was to gather some of the best experts in the field to consider the current state of knowledge, ascertain which questions remain to be addressed, and identify the most promising approaches to addressing those questions. The purpose of this report is to document that discussion. Throughout the planet's first billion years, planetary-scale processes-including differentiation, hydrodynamic escape, volcanism, large impacts, erosion, and sedimentation-rapidly modified the atmosphere and crust. How did these processes operate, and what were their rates and interdependencies? The early environment was also characterized by both abundant liquid water and plentiful sources of energy, two of the most important conditions considered necessary for the origin of life. Where and when did the most habitable environments occur? Did life actually occupy them, and if so, has life persisted on Mars to the present? Our understanding of early Mars is critical to understanding how the planet we see today came to be.

Increased intake of calcium reverses vitamin B12 malabsorption induced by metformin.

OBJECTIVE: Of patients who are prescribed metformin, 10-30% have evidence of reduced vitamin B12 absorption. B12-intrinsic factor complex uptake by ileal cell surface receptors is known to be a process dependent on calcium availability Metformin affects calcium-dependent membrane action. The objective of this study was to determine the magnitude and mechanism of the reduction in serum vitamin B12 after metformin administration. RESEARCH DESIGN AND METHODS: A comparative study design was employed using 2 groups (metformin and control). A total of 21 patients with type 2 diabetes received sulfonylurea therapy; 14 of these 21 patients were switched to metformin. Monthly serum total vitamin B12 measurements and holotranscobalamin (holoTCII) (B12-TCII) were performed. After 3 months of metformin therapy, oral calcium supplementation was administered. RESULTS: Serial serum vitamin B12 determinations revealed a similar decline in vitamin B12 and holoTCII. Oral calcium supplementation reversed the metformin-induced serum holoTCII depression. CONCLUSIONS: Patients receiving metformin have diminished B12 absorption and low serum total vitamin B12 and TCII-B12 levels because of a calcium-dependent ileal membrane antagonism, an effect reversed with supplemental calcium.

Iron disorders can mimic anything, so always test for them.

Routinely measuring iron status is necessary because not only are about 6% of Americans in significant negative iron balance, but about 1% have iron overload. Serum ferritin is in equilibrium with body iron stores, and is the only blood test that measures them. Barring inflammation, each one ng (0.0179 pmol) ferritin/ml of serum indicates approximately 10 mg (0.179 mmol) of body iron stores. Very early Stage I positive balance is best recognized by measuring saturation of iron binding capacity. Conversely, serum ferritin best recognizes early (Stage I and II) negative balance. Deviations from normal are: 1. Both stages of iron depletion (i.e. low stores, no dysfunction). Negative iron balance Stage I is reduced iron absorption producing moderately depleted iron stores. Stage II is severely depleted stores, without dysfunction. These stages include over half of all cases of negative iron balance. Treated with iron, they never progress to dysfunction, i.e. to disease. 2. Both stages of iron deficiency. Deficiency is inadequate iron for normal function, i.e. dysfunction, disease. Negative balance Stage III is dysfunction without anemia; Stage IV is with anemia. 3. Positive iron balance: Stage I is a multi-year period without dysfunction. Supplements of iron and/or vitamin C promote progression to dysfunction (disease). Iron removal prevents progression. Stage II is iron overload disease, encompassing years of insidiously progressive damage to tissues and organs from iron overload. Iron removal arrests progression.

Nutritional anemias.

Folate, vitamin B12, and iron are the subjects of active biochemical and molecular research so that further understanding of their metabolism in health and in a wide variety of Inherited and acquired diseases can be achieved. The roles of folate and vitamin B12 in cardiovascular and neurologic diseases and in neural tube defects (NTDs) will be further explored in the next decade. The effects of prophylactic therapy and of food fortification with the vitamins on these diseases remain to be established. Iron deficiency is a public health problem in all countries and prevention or treatment, particularly in children in developing countries, are major goals. The increased recent understanding of iron metabolism and absorption may clarify the etiology of diseases of iron metabolism and of dietary iron overload. Improved iron chelation therapy for transfusion-dependent patients with refractory anemias will continue to be actively researched over the next decades.

Vitamin B-12: plant sources, requirements, and assay.

Vitamin B-12 is of singular interest in any discussion of vegetarian diets because this vitamin is not found in plant foods as are other vitamins. Many of the papers in the literature give values of vitamin B-12 in food that are false because as much as 80% of the activity by this method is due to inactive analogues of vitamin B-12.

Recommended dietary intakes (RDI) of folate in humans.

Extensive evidence is presented that 3 micrograms folate/kg (6.8 nmol/kg) body weight daily will not only maintain adequate folate nutriture but also a substantial reserve body pool in normal persons. Recommendations appropriate to this extensive evidence are presented.