Relationships Among Rheological, Sensory Texture, and Swallowing Pressure Measurements of Hydrocolloid-Thickened Fluids

The objective of this study was to examine the relationships among three categories of measurements (rheological, sensory texture, and swallowing pressure) from fluids thickened to two different viscosities with 15 different hydrocolloids. Fluids at viscosities of 300 and 1500 cP (at 30 s(-1)) were targeted because these are the viscosities corresponding to the barium standards used in radiographic dysphagia diagnosis. Within the low viscosity (nectar) fluids (300 cP), the sensory properties thickness, stickiness, adhesiveness, mouth coating, and number of swallows were highly positively correlated with each other and highly positively correlated with the flow behavior index, n value (an indicator of shear-thinning behavior). Within the higher viscosity (thin honey) fluids (1500 cP), the sensory textures of adhesiveness, stickiness, mouth coating, and number of swallows correlated positively with rheological measures of n value. Swallowing pressures measured in the anterior oral cavity correlated negatively with the consistency coefficient k [shear stress/(shear rate) (n) ]. Samples that were more shear thinning (lower n values, higher k values) were generally perceived as less thick, with less adhesive properties (stickiness, adhesiveness, mouthcoating, and number of swallows). This information can be useful for selecting thickeners for people with dysphagia. A desirable thickener for many dysphagic patients would be one that allowed for a safe swallow by being viscous enough to reduce airway penetration, yet pleasant to drink, having the minimal perceived thickness and mouthcoating associated with greater shear thinning.

Chemotherapy affects the pattern of failure after shear loading of the proximal tibial growth plate

INTRODUCTION

Tibial bones are shorter and less resistant to shear forces after treatment with doxorubicin, methotrexate, or cisplatin. We investigated the pattern of failure after shear loading of the proximal tibial growth plate in rats treated with these chemotherapeutic agents.

MATERIALS AND METHODS

Male Wistar rats from the age of 4 weeks were given doxorubicin intravenously at 15 mg/m2 body surface area (BSA), methotrexate 60 mg/m2 BSA, or cisplatin 7.5 mg/m2 BSA. There was one nontreated control group fed ad libitum an d a diet control group for each drug-treated group. At the age of 13 weeks the tibial bones were dissected. The proximal growth plate was shear loaded to failure in the posteroanterior direction. The pattern of failure through the growth plate was examined.

RESULTS

In rats fed ad libitum the failure pattern ran mainly through the transitional zone between proliferating and hypertrophic chondrocytes, but the pattern of failure showed considerable variability. The pattern in rats treated with methotrexate or cisplatin and that in their diet controls were comparable. In rats treated with doxorubicin the fracture ran mainly through the trabecular zone.

CONCLUSIONS

Doxorubicin affects the pattern of failure after shear loading of the proximal tibial growth plate, but methotrexate and cisplatin do not. Special attention should be paid to epiphyseal injuries in children treated with doxorubicin.

Cannabis (hemp) positive skin tests and respiratory symptoms

BACKGROUND

We have noted several patients who had rhinitis and/or asthma symptoms when exposed to Cannabis plants in the summer months. Cannabis plants are common in the Midwest.

OBJECTIVES

To examine whether Cannabis might be a clinically important allergen, we determined Cannabis pollination patterns in the Omaha area for 5 years, the prevalence of skin test positivity, and the association with respiratory symptoms.

METHODS

Airborne Cannabis (and other weed) pollens were collected using a Rotorod air impactor, and pollen counts were done using a standardized protocol.

RESULTS

Measurable Cannabis pollen count was not recorded until the last 2 weeks of July. Peak pollination typically occurred during mid- to late-August, and comprised up to 36% of the total pollen counts. Cannabis pollen was not observed after mid-September. To determine the prevalence of skin test positivity, we added Cannabis to the multi-test routine skin test battery. Seventy-eight of 127 patients tested (61%) were skin test positive. Thirty of the 78 patients were randomly selected to determine if they had allergic rhinitis and/or asthma symptoms during the Cannabis pollination period. By history, 22 (73%) claimed respiratory symptoms in the July through September period. All 22 of these subjects were also skin test positive to weeds pollinating during the same period as Cannabis (ragweed, pigweed, cocklebur, Russian thistle, marsh elder, or kochia).

CONCLUSIONS

The strong association between skin test reactivity, respiratory symptoms, and pollination period suggests that Cannabis could be a clinically important aeroallergen for certain patients and should be further studied.

Cytoskeletal maturation in cultured hippocampal slices

We have studied the expression of genes for neuronal microtubule-associated proteins in organotypic hippocampal slice cultures using immunoblotting and polymerase chain reaction combined with reverse transcription on a single-slice basis. We found that for microtubule-associated protein 2 and tau the same developmental transition from embryonic to adult splice variants occurs in the cultures as has been described previously in intact brain. This finding indicates that the maturation profile of these proteins is not determined by extrinsic inputs but by a cell-autonomous programme or local factors within the hippocampus. Our study corroborates previous data for the maturation of hippocampal slice cultures and is also the first biochemical analysis on the level of the neuronal cytoskeleton of this widely used model system for the hippocampus.

Preprotachykinin-A gene expression occurs transiently in the developing rat endocrine pancreas and can be regulated in RINm5F cells

We have reported previously that the rat insulinoma cell lines, RINm5F and RINr1046-38, express the preprotachykinin(PPT)-A gene, which encodes the tachykinin peptides, substance P and neurokinin A. Because endocrine cells of the adult rat pancreas do not appear to express PPT-A, we investigated whether the gene is expressed by rat pancreatic endocrine cells during development. We used immunohistochemistry, employing different substance P and neurokinin A antibodies, to show that many endocrine cells of the fetal and neonatal rat pancreas synthesise these products of PPT-A gene expression. Colabeling experiments revealed that a significant number of both insulin-containing and non-insulin-containing cells express tachykinins. After postnatal day 20, the number of tachykinin-immunoreactive pancreatic islet cells declines and, as already reported, none were detected in the adult rat pancreas. The transient expression of PPT-A by the developing endocrine pancreas is a novel finding. Substance P and neurokinin A are known to have trophic actions and may serve as growth factors during pancreatic islet development. PPT-A gene expression by RINm5F and RINr1046-38 cells is further evidence that these cells resemble developing pancreatic endocrine cells. They are potentially valuable as unique models for studying the regulation of tachykinin biosynthesis. We provide evidence in this study, using quantitative PPT-A messenger RNA analysis, that PPT-A expression in RINm5F cells may be up-regulated by activation of protein kinase C, down-regulated by activation of glucocorticoid receptors, and is not significantly affected by changes in intracellular cAMP levels.

Characterisation of the expression and post-translational processing of the preprotachykinin-I gene and the regulated release of tachykinins by the RINm5F cell-line

Normal transcription and postranslational processing of the preprotachykinin (PPT)-I gene and regulated release of substance P and neurokinin A by the rat pancreatic endocrine cell-line, RINm5F, has been demonstrated, using radioimmunoassays (RIAs), reversed-phase (rp)HPLC and Northern blot analysis. This is the first stable cell-line found to express the PPT-I gene and provides an opportunity for investigating PPT-I gene expression and tachykinin biosynthesis. RIN5mF cells are a model for the pancreatic beta-cell, which is not known to exhibit PPT-I gene expression which may, therefore, be a feature of the transformed state of these cells. These data may imply that the tachykinins are important in pancreatic islet embryogenesis.

[Chronic immunoproliferative syndromes]

Immunoproliferative syndromes are etiologically unclear, rare diseases which involve polyclonal B- and/or T-cell proliferations and frequently develop into malignant non-Hodgkin-lymphoma. Typically, these diseases are characterized by lymphadenopathies, hepatosplenomegaly, general fatigue and autoimmune phenomena. Here we briefly outline 6 syndromes, two of which--the "pluripotential chronic immunoproliferative syndrome" (CPIS) and the "angioimmunoblastic lymphadenopathy" (AILD)--are discussed in more detail. We favor the notion that CPIS is a variant form of AILD clinically dominated by severe autoimmune hemolytic anemia. Both diseases share the high frequency of anti-cytoskeleton autoantibodies.