Early COVID-19 pandemic modeling: Three compartmental model case studies from Texas, USA.

The novel coronavirus (SARS-CoV-2) emerged in late 2019 and spread globally in early 2020. Initial reports suggested the associated disease, COVID-19, produced rapid epidemic growth and caused high mortality. As the virus sparked local epidemics in new communities, health systems and policy makers were forced to make decisions with limited information about the spread of the disease. We developed a compartmental model to project COVID-19 healthcare demands that combined information regarding SARS-CoV-2 transmission dynamics from international reports with local COVID-19 hospital census data to support response efforts in three Metropolitan Statistical Areas (MSAs) in Texas, USA: Austin-Round Rock, Houston-The Woodlands-Sugar Land, and Beaumont-Port Arthur. Our model projects that strict stay-home orders and other social distancing measures could suppress the spread of the pandemic. Our capacity to provide rapid decision-support in response to emerging threats depends on access to data, validated modeling approaches, careful uncertainty quantification, and adequate computational resources.

Multi-element composition of soils of seasonal wetlands across North Dakota, USA.

The main goal of this study was to assess if the soils of wetlands of different condition varied in terms of element composition. The rationale was that compared to wetlands of good condition, wetlands of poor condition-which in the region have typically been disturbed by agricultural activities, are lower in biodiversity and have fewer native species-would have been altered in their physical and chemical soil characteristics. This in turn would have altered the element composition of the soils. The concentrations of about 50 elements in the topsoil of 43 seasonal wetlands of varying condition, as measured by plant community based assessments, across North Dakota were determined. Organic matter content of the soils increased as condition increased, and it was the most important variable explaining 40 % of variation in the concentrations of elements. This can be partly explained by binding of elements to organic matter (S, Se) and for most other elements (that bind mostly to the inorganic fraction) by displacement by organic matter. The biogeochemistry of S is further implicated in the distribution of Ca, most likely via formation of insoluble gypsum (calcium sulfate).

Cellular events of acute, resolving or progressive COVID-19 in SARS-CoV-2 infected non-human primates.

Understanding SARS-CoV-2 associated immune pathology is crucial to develop pan-effective vaccines and treatments. Here we investigate the immune events from the acute state up to four weeks post SARS-CoV-2 infection, in non-human primates (NHP) with heterogeneous pulmonary pathology. We show a robust migration of CD16 expressing monocytes to the lungs occurring during the acute phase, and we describe two subsets of interstitial macrophages (HLA-DR+CD206-): a transitional CD11c+CD16+ cell population directly associated with IL-6 levels in plasma, and a long-lasting CD11b+CD16+ cell population. Trafficking of monocytes is mediated by TARC (CCL17) and associates with viral load measured in bronchial brushes. We also describe associations between disease outcomes and high levels of cell infiltration in lungs including CD11b+CD16hi macrophages and CD11b+ neutrophils. Accumulation of macrophages is long-lasting and detectable even in animals with mild or no signs of disease. Interestingly, animals with anti-inflammatory responses including high IL-10:IL-6 and kynurenine to tryptophan ratios show less severe illness. Our results unravel cellular mechanisms of COVID-19 and suggest that NHP may be appropriate models to test immune therapies.

Glycosylation of thyroid-stimulating hormone in pituitary tumor cells: influence of high mannose oligosaccharide units on subunit aggregation, combination, and intracellular degradation.

We have studied the glycosylation of TSH in cell culture and have examined the influence of carbohydrate on subunit aggregation, intracellular degradation, and combination. Dispersed mouse thyrotropic tumor cells were labeled by pulse-chase methods with [35S]methionine and various 3H-labeled carbohydrates; cell lysates and media were precipitated with antisera to TSH alpha and TSH beta, and the products were analyzed by sodium dodecyl sulfate gradient gel electrophoresis without or with preexposure to Endoglycosidase (Endo) H. At early pulses, both intracellular alpha and beta were mainly composed of one Endo H-sensitive (high mannose) carbohydrate unit and a small amount of nonglycosylated forms; alpha only had the posttranslational addition of a second high mannose unit. With increasing chase times up to 18 h, intracellular subunits showed a slow but progressive increase in Endo H-resistant (complex) forms, and media subunits were completely resistant. Preincubation of cells with tunicamycin caused production of nonglycosylated subunits that showed a high degree of aggregation, especially after heating at 37 C under nonreducing conditions. Unlike glycosylated subunits, which were not degraded, nonglycosylated subunits were 50-65% degraded intracellularly before secretion; the degradation caused by tunicamycin was specific for TSH subunits and not noted for other 35S-labeled proteins. Incubation of various 35S-labeled alpha forms with excess unlabeled TSH beta showed high combining activity for intracellular alpha with two high mannose units, intermediate activity for media alpha with two complex units, and low activity for intracellular alpha with one high mannose unit or nonglycosylated media alpha. These data suggest that the initial glycosylation with high mannose carbohydrate units prevents intracellular aggregation and degradation of TSH subunits and enhances attainment of the conformation necessary for alpha- and beta-subunit combination.

Scintigraphic evidence of adrenal cortical dysfunction in the polycystic ovary syndrome.

The polycystic ovary syndrome (PCO) is frequently associated with elevated plasma levels of adrenal androgens and/or abnormal adrenal androgen responses to hormonal stimulation and suppression. Because of the overlap in the output of hormones between the adrenal glands and the ovaries, we measured adrenal iodocholesterol accumulation as an index of adrenocortical function in 11 women with PCO confirmed by laparoscopy or culdoscopy. All patients had normal dexamethasone suppression of plasma cortisol or urinary 17-hydroxycorticosteroid excretion. 6 beta-[131I]Iodomethylnorcholesterol (NP-59) adrenal scintiscans showed bilateral and excessive adrenal cortical uptake in PCO patients [0.46 +/- 0.08% (+/- SE) of the administered dose compared to 0.21 +/- 0.01% in a group of normal women; P less than 0.05]. The elevation of adrenal cortical NP-59 uptake in PCO was quantitatively similar to that in women with ACTH-dependent Cushing's syndrome (0.64 +/- 0.11%; P greater than 0.1). These data support the presence of abnormal adrenal cortical function in patients with PCO. The adrenal dysfunction of PCO most likely represents abnormal control of adrenal androgen production/secretion.

The relationship of adrenal gland iodomethylnorcholesterol uptake to zona glomerulosa function in primary aldosteronism.

Dexamethasone suppression adrenal scintiscans were performed on 37 patients referred for evaluation of primary aldosteronism (PA). Twenty-one had aldosterone-secreting adrenal adenoma (AA) and 16 had bilateral adrenal hyperplasia (BAH). The diagnosis of either AA or BAH was confirmed by adrenalectomy in 19 of 21 subjects with AA and by adrenal venous sampling in 15 of 16 patients with BAH. Biochemical parameters of PA were found in each patient while on both high (150 meq Na) and low salt (10 meq Na) intakes. Urinary aldosterone excretion values were 49.7 +/- 10.2 (+/- SEM) micrograms/day (range, 11.2-103.9) and 44.2 +/- 12.1 micrograms/day (range, 14.3-128.0) in AA patients on high and low salt intakes, respectively. In BAH patients, urinary aldosterone values were 29.1 +/- 2.6 micrograms/day (range, 10.0-55.0) and 47.7 +/- 9.0 micrograms/day (range, 23.0-102.0) on high and low salt intakes, respectively. A semioperator-independent computer algorithm was used to calculate adrenal gland uptake of [131I]6 beta-iodomethyl-19-norcholesterol (NP-59) in PA patients and in 7 patients with essential hypertension. NP-59 adrenal uptake values were 0.20 +/- 0.02%/dose (range, 0.03-0.72), 0.28 +/- 0.04% (range, 0.10-0.65), and 0.14 +/- 0.02%/dose (range, 0.08-0.30) in AA, BAH, and essential hypertension, respectively. A significant correlation was found between adrenal gland uptake of NP-59 and urinary aldosterone excretion in AA (r = 0.93; P less than 0.001) and BAH (r = 0.6; P less than 0.01) patients. These data confirm that adrenal gland accumulation of NP-59 while on dexamethasone suppression can be used to characterize abnormal zona glomerulosa function in PA, in addition to localizing AA and differentiating AA from BAH.

Quantitative multiple sclerosis plaque assessment with magnetic resonance imaging. Its correlation with clinical parameters, evoked potentials, and intra-blood-brain barrier IgG synthesis.

Magnetic resonance imaging (MRI) of the cerebrum, cerebellum, brain stem, and upper cervical cord was performed in 62 individuals with clinically definite chronic, progressive multiple sclerosis (MS). The total area of MRI-demonstrated lesions was measured from film enlargements for each region using an interactive image analysis system. While the MRI was abnormal in 60 (97%) of 62 patients, the visual-evoked potentials in 51 (85%) of 60 patients, the brain stem auditory-evoked potentials (BAEPs) in 24 (46%) of 52 patients, and the somatosensory-evoked potentials (SSEPs) in 45 (89%) of 54 patients, an abnormal intra-blood-brain barrier (BBB) IgG synthesis rate, IgG oligoclonal bands, or both were found in all 62 patients. The total area of MRI abnormality in the cerebrum was significantly correlated only with the intra-BBB IgG synthesis rate, abnormal visual-evoked potentials, impaired performance on the Symbol Digit Modalities Test (SDMT), and one test of standing duration in the quantitative examination of neurologic function (QENF). The brain stem lesion area correlated with the Kurtzke expanded disability status scale and brain stem functional systems score, the ambulation index, abnormal BAEPs, and impaired performance on the SDMT as well as multiple tests of upper and lower extremity function in the QENF. The cerebellar lesion area correlated with impaired performance on the SDMT and primarily upper extremity testing in the QENF.(ABSTRACT TRUNCATED AT 250 WORDS)

Metaiodobenzylguanidine to map scintigraphically the adrenergic nervous system in man.

Metaiodobenzylguanidine (MIBG) localizes in adrenergic neurons; MIBG labeled with 123I then serves as an analog of norepinephrine, and concentrations of [123I]MIBG reflect sites of adrenergic neurons in organs. Movements of [123I]MIBG into and out of organs were measured by quantitative scintigraphy in man. We perturbed adrenergic neuron function in several ways, and [123I]MIBG concentrations in the heart were subsequently altered in patterns consistent with the concept that [123I]MIBG resides mostly in adrenergic neurons. Uptake of [123I]MIBG into the heart was inhibited by the tricyclic drug, imipramine, and this agent also accelerated the rate of loss of [123I]MIBG. Phenylpropanolamine, a sympathomimetic drug that acts by displacing norepinephrine from neurons, increased the rates of loss of [123I]MIBG from the heart. Exercise was followed by a movement of [123I]MIBG into blood and urine. Generalized autonomic neuropathies were associated with marked diminutions of [123I]MIBG uptake into the heart. We conclude that quantitative scintigraphy in patients will enable determinations of regional disturbances in integrity (by measuring uptake of [123I]MIBG) and function (by measuring rates of loss of [123I]MIBG) of the adrenergic nervous system in the heart.

Clinical significance of the solitary functioning adrenal gland.

To assess the compensatory functional and anatomic changes in the remaining adrenal cortex after unilateral adrenalectomy or in the unaffected adrenal in patients with unilateral adrenal destruction by neoplasm, 17 patients with a single, functioning adrenal gland and normal indices of adrenocortical function, nine after adrenalectomy and eight with a unilateral, destructive adrenal lesion were studied with 131I-6 beta-iodomethyl-19-norcholesterol (NP-59) scintigraphy and computed tomography. Adrenal masses with a mean (+/- s.d.) diameter of 2.8 +/- 1.0 cm; (range 1-4 cm; 95% confidence interval (Cl), 2.5-3.1 cm) were identified by computed tomography in seven of nine patients in the remaining adrenal cortex at variable times (6.1 +/- 5.9 y; range 0.5-19 y) after unilateral adrenalectomy. Mean (+/- s.e.m.) NP-59 uptake was elevated (p less than 0.01) in both adrenalectomy and adrenal destruction groups, mean uptake (+/- s.e.m.) was 0.32% +/- 0.04% administered dose (95% Cl, 0.24%-0.4% administered dose) as compared to normal (0.16% +/- 0.05% administered dose, 95% Cl, 0.06%-0.26% administered dose). The remaining adrenal cortex may be anatomically abnormal after unilateral adrenalectomy and demonstrate compensatory, increased NP-59 uptake in the presence of overall, normal adrenocortical function.

Portrayal of pheochromocytoma and normal human adrenal medulla by m-[123I]iodobenzylguanidine: concise communication.

The radiopharmaceutical m-[131I]iodobenzylguanidine (I-131 MIBG), which is readily taken up by adrenergic vesicles, produces scintigraphic images of pheochromocytomas in man but rarely visualizes normal adrenal glands. Iodine-123 has many potential advantages over I-131 as a radiolabel for MIBG, including shorter half-life, freedom from beta emissions, and increased gamma-camera efficiency. In this study, diagnostic doses of MIBG labeled with I-131 and I-123, with nearly equivalent radiation dosimetry, were compared as imaging agents in eight patients with known or suspected pheochromocytoma. Images of superior quality were obtained with I-123 MIBG, and lesions not visualized using I-131 MIBG were portrayed. In addition, the normal adrenal medullae were visualized on the I-123 MIBG scintigrams in six out of eight patients.

Iodine-123-4-amino-3-iodobenzylguanidine, a new sympathoadrenal imaging agent: comparison with iodine-123 metaiodobenzylguanidine.

Iodine-123-4-amino-3-iodobenzylguanidine ([123I]AIBG), an analog of 123I metaiodobenzylguanidine ([123I]MIBG), has an advantage in having a more rapid and simple synthesis. This, combined with animal data that suggested a greater affinity of the new radiopharmaceutical for the autonomic innervation of the myocardium led us to study the biodistribution of [123I]AIBG in three men with metastatic pheochromocytoma. In all instances, [123I]AIBG revealed the same metastatic deposits shown by [123I]MIBG. Iodine-123 AIBG uptake, however, was greater than [123I]MIBG in lung, gut, and spleen. These higher backgrounds may pose diagnostic problems in some cases.

Selective membrane toxicity of aminoglycoside antibiotics in membrane vesicles isolated from proximal renal tubules of the rat.

A considerable body of evidence suggests that the nephrotoxic potential of aminoglycoside antibiotics may be associated with the degree of membrane binding and subsequent membrane damage in the renal tubules. In this study, we isolated functional basolateral and luminal membrane vesicles from rat renal cortex, incubated each membrane type in the presence of 1 mM concentrations of either neomycin, netilmicin, gentamicin, hydroxygentamicin, or amikacin, and monitored the activities of the marker enzymes alkaline phosphatase (ALP) and lambda-glutamyltransferase (GGT) (luminal) or ouabain-sensitive Na+,K+-ATPase (basolateral) to determine if there were any selective drug-related alterations of enzyme activities. While none of the five aminoglycosides had any substantive effect upon enzyme activities of luminal vesicles, all five drugs inhibited the basolateral marker enzyme. Neomycin produced the greatest inhibition, hydroxygentamicin and amikacin the least, and gentamicin and netilmicin were intermediate in the inhibition of the enzyme. These results are in accordance with the known relative nephrotoxicity of these same drugs and indicate the usefulness of isolated renal membrane vesicles for in vitro toxicological studies of novel aminoglycosides.

Toxicity associated with high-dose cytosine arabinoside and total body irradiation as conditioning for allogeneic bone marrow transplantation.

Seventy-three patients with hematological cancers undergoing allogeneic bone marrow transplantation (BMT) were evaluated for event-free survival (EFS) and toxicity. All received 36 g/m2 cytosine arabinoside (HDA) and 1200 cGy fractionated total body irradiation (TBI). We assessed the association of EFS and toxicities with the following risk factors; age, gender, diagnosis, initial relapse risk and patient-donor histocompatibility. The EFS probability is 33% at 800 days post-BMT. Twenty-six patients (36%) died of toxicity within 100 days and 14 (19%) have relapsed. EFS was inversely associated with age (P < 0.0001) and initial relapse risk (P = 0.007). The risk of pulmonary (P = 0.023) and hepatic toxicity (P = 0.011) increased with age. Diagnosis other than acute lymphoblastic leukemia (ALL) was a risk factor (P = 0.015) for graft-versus-host disease (GVHD); and fewer ALL patients died from toxicity (P = 0.014). The probability of sepsis within 100 days post-BMT correlated (P = 0.007) with initial relapse risk. We conclude: (1) the lower EFS and greater pulmonary and hepatic toxicity associated with increasing age indicate a need for less toxic regimens that maintain high antileukemic efficacy for older patients; (2) the high GVHD and sepsis rates seen in certain categories of patients indicate a need for careful definition of eligibility criteria for this still highly toxic treatment.

The duration of non-rodent toxicity studies for pharmaceuticals. International Conference on Harmonication (ICH).

At the present time, there are no uniform standards for the duration of non-rodent chronic toxicity studies. The European Union (EU) requires a 6-month non-rodent study. In Japan, a 6-month study is sufficient for most, but not all, compounds. The U.S. Food and Drug Administration (FDA) maintains its standard duration of 12 months for non-rodents, with 6-month studies accepted for some clinical indications on a case-by-case basis. To achieve harmonization on the duration of non-rodent toxicity studies, each member regulatory region (EU, U.S., and Japan) of the International Conference on Harmonization (ICH) collected non-rodent studies with significant new toxicological findings that had occurred after 6 months. An ICH expert working group was organized that included representatives from the regulatory authorities of each ICH region, to jointly review all available case studies for the purpose of arriving at a consensus on the best duration time for non-rodent toxicity studies. Eighteen case studies were identified and evaluated (16 original cases plus 2 additional FDA cases); most of the toxicities identified fell into the following categories: (1) toxicities identified at 6 months; (2) toxicities observed at 12 months, which were absent or considered isolated and not noteworthy findings at 6 months; (3) drug-related deaths or morbidity that occurred between 6 and 12 months, with a pattern of toxicity that permitted the interpolation of findings to an intermediate interval between 6 and 12 months; and (4) a shift in the dose response for toxicity with increasing duration of drug exposure. Of the 18 cases evaluated, 11 supported a study-duration of 9-12 months, 4 supported a duration of 12 months, and the 3 remaining cases indicated that a 6-month study would be adequate. The working group concluded that there was sufficient evidence to support a harmonized 9-month duration for non-rodent toxicity studies, which would be applicable for most categories of pharmaceuticals.

Translocation (4;11) in acute myelogenous leukemia.

A child with acute myelogenous leukemia is presented. Cytogenetic analysis of her leukemic cells revealed a (4;11)(q12;q23) translocation. The slight difference in the breakpoint on chromosome #4 from previously reported cases of t(4;11) may account for the degree of myeloid differentiation expressed. Acute leukemia associated with t(4;11) is a unique subgroup that originates in an early myeloid stem cell and carries a poor prognosis.

Porous ceramics as bone graft substitutes in long bone defects: a biomechanical, histological, and radiographic analysis.

Three porous ceramic bone graft materials were compared with regard to their ability to heal a 2.5 cm defect created surgically in a bilateral canine radius model. The ceramic materials were analyzed at 12 and 24 weeks after surgery and included tricalcium phosphate, hydroxyapatite, and collagen hydroxyapatite, which contained a mixture of 35% tricalcium phosphate and 65% hydroxyapatite with added collagen. Each material was evaluated alone and with added bone marrow aspirate. All the implants were compared with a graft of autogenous cancellous bone in the contralateral radius. Biomechanical testing and radiographic evaluation revealed that the addition of bone marrow aspirate was essential for tricalcium phosphate and hydroxyapatite to achieve results comparable with those of cancellous bone. Collagen hydroxyapatite performed well without the addition of bone marrow, although the addition of marrow did have a positive effect. Further qualitative radiographic and histological analysis demonstrated that tricalcium phosphate was the only ceramic that showed any sign of degradation at 24 weeks. This observed degradation proved to be an important factor in evaluating radiographs because the radiodensity of collagen hydroxyapatite and hydroxyapatite interfered with the determination of radiographic union. At 24 weeks, tricalcium phosphate with bone marrow was the material that performed most like cancellous bone. In this study, the biomechanical and radiographic parameters of tricalcium phosphate with bone marrow were roughly comparable with those of cancellous bone at 12 and 24 weeks. Tricalcium phosphate was the only implant that showed significant evidence of degradation at 24 weeks by both histological and radiographic evaluations, and this degradation took place only after a degree of mechanical competence necessary for weight-bearing was achieved.

Staphylococcal scalded skin syndrome.

Staphylococcal scalded skin syndrome is a rarely reported superficial desquamating eruption found in patients who have otherwise toxic conditions. Its early recognition and treatment can be lifesaving. A case of staphylococcal scalded skin syndrome is reported in a patient with chronic liver failure.

Radionuclide cisternography in the preterm neonate.

A technique is presented for the bedside performance of radionuclide cisternography in the preterm neonate. Using a portable gamma camera, with a low energy, converging collimator, high quality diagnostic images were obtained in 31 infants, following the lumbar subarachnoid injection of 100 micro Ci In-111 DTPA. The technique is safe, and provides valuable information about CSF dynamics unavailable by any other method.

The role of time and size in ontogenetic allometry: II. An empirical study of human growth.

The changes in shape that occur as a consequence of size changes during the third trimester (22 to 36 weeks post conception) of human growth are examined for muscular, tendinous and skeletal measurements of the lower limb. Gestational age and weight were highly correlated, but not linear. Several models appear to have equivalent fits to these data. The skeletal measurements were linear with body weight, but did not follow the predictions of any biomechanical model. Femur length grows more quickly than body weight, as does femur diameter. The ratio of length to diameter is nearly one, suggesting that the relative shape of the femur does not change with weight. The weights of the two muscles examined were nonlinear as functions of age or weight; Gompertz models with different coefficients fits these data best. The lengths of the two tendons were linear with age, but tendon weights were best described by nonlinear Gompertz models. One difficulty of the Gompertz models stems from the lack of an upper asymptote in these data. The data fit the lower half of the curve, however the model predicts an asymptote beyond the range of data available. The relative patterns of growth, i.e. muscles growing faster than tendons, suggest hypotheses that need to be tested with a larger data set. These include growth of muscles relative to bones or tendons in other regions, e.g., the upper limb or the cranium, and an extension of the data in time.