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The given text is a collection of letters published in the Maine Antique Digest. The letters cover a range of topics, including requests for collections of family and business letters, advertisements for antique dealers and auctions, corrections to previous articles, and reflections on the antiques industry. The letters express diverse perspectives and opinions, with some discussing specific items of historical importance and others addressing political and cultural issues. The letters provide insights into the world of antique collecting and offer readers a glimpse into the interests and concerns of those involved in the industry. [Extracted from the article]

Background:Prosthetic‐driven implant dentistry requires predictable procedures for alveolar ridge augmentation. The objective of this pilot study was to evaluate bone regeneration in mandibular, full‐thickness, alveolar ridge, saddle‐type defects following surgical implantation of recombinant human bone morphogenetic protein‐2 (rhBMP‐2) in a novel hyaluronan (HY) sponge carrier. This sponge was fabricated from auto‐crosslinked HY. Methods:Alveolar ridge defects (∼15 × 10 × 10 mm), 2 per jaw quadrant, were surgically prepared in each of 3 young adult American fox hounds. Four defects were immediately implanted with rhBMP‐2/HY. Three defects were implanted with rhBMP‐2 in an absorbable collagen sponge (ACS) carrier (positive control). The rhBMP‐2 solution (1.5 ml at 0.2 mg/ml) was soak‐loaded onto the HY and ACS sponges. Three defects were implanted with HY sponges soak‐loaded with buffer without rhBMP‐2 (negative control), while 2 defects served as surgical controls. The animals were euthanized at 12 weeks postsurgery for histometric analysis. Results:Clinically, alveolar ridge defects receiving rhBMP‐2/ACS exhibited a slight supracrestal expansion, while defects receiving rhBMP‐2/HY were filled to contour. In contrast, the HY and surgical controls exhibited ridge collapse. rhBMP‐2/HY‐treated defects exhibited a dense bone quality without radiolucent regions observed in defects treated with rhBMP‐2/ACS. The histometric analysis showed 100% bone fill for the rhBMP‐2/ACS defects and 94%, 58%, and 65% bone fill for the rhBMP‐2/HY, HY, and surgical control defects, respectively. Conclusions:The conclusions are based on data from 2 of 3 animals in the study. In one animal, no response to rhBMP‐2 was observed with either carrier, and the animal may have been a non‐responder of unknown nature. With this limitation, the observations herein suggest that: 1) HY supports significant bone induction by rhBMP‐2; 2) the rhBMP‐2–induced bone assumes qualities of the immediate resident bone; 3) HY alone exhibits no apparent osteoconductive potential; and 4) HY appears to resorb within a 12‐week healing interval in the absence or presence of rhBMP‐2. Thus, HY appears to be a suitable candidate carrier for rhBMP‐2. J Periodontol 2001;72:651‐658.

Background:This investigation is one of a series of projects seeking to ascertain whether hyaluronic acid (HA) is therapeutically effective in tissue regeneration procedures. The rationale for these investigations is to test the hypothesis that HA can serve as a bioabsorbable carrier for other substrates as well as itself actively promote the regeneration of tissue. Methods:In this paper, we report on the bacteriostatic and bactericidal properties of 3 molecular weight formulations of recombinant HA (low, 141 kD; medium, 757 kD; and high, 1,300 kD) on selected oral and non‐oral microorganisms in the planktonic phase. Three concentrations of each HA formulation were screened, 0.5, 1.0, and 2.0 mg/ml, using a standard broth culture assay. Results:Recombinant HA exerted varied bacteriostatic effects on all the bacterial strains tested depending on its molecular weight (MW) and concentration. The high concentrations of the medium MW HA had the greatest bacteriostatic effect, particularly on the Actinobacillus actinomycetemcomitans, Prevotella oris, Staphylococcus aureus, and Propionibacterium acnesstrains. The 1.0 mg/ml concentration of high MW HA had the greatest overall bacteriostatic effect, inhibiting the growth of all 6 bacterial strains tested. Among the bacterial strains studied, HA was found to have no bactericidal effects, regardless of concentration or molecular weight. Conclusions:The results of this study suggest that HA in the MW range of 1,300 kD may prove beneficial in minimizing bacterial contamination of surgical wounds when used in guided tissue regeneration surgery. J Periodontol 1999;70:370‐374.

Shih, C. and G. W. Bernard. Neurogenic substance P stimulates osteogenesis in vitro Peptides 18(2) 323–326, 1997.—Previous studies have shown that there is colocalization of substance P (SP) and calcitonin gene-related peptitde (CGRP)-immunoreactive nerve fibers in bone, periosteum and bone marrow. Because SP may also possibly play a role in bone formation, we decided to test whether it has an osteogenic stimulating effect on developing bone in vitro. To this end, 0.4, 4 and 40 μg/ml of SP in BGJb medium was added daily to 3 million light density (LD) bone marrow white cells which were separated by Ficoll-Paque density gradient separation then seeded onto a previously prepared fibroblast feeder layer in Petri dishes. Seven days after adding SP, in the control without SP there were 2 bone colonies; with 0.4 μg of SP there were 3 colonies; with 4 μg there were 5 μg colonies; with 40 μg there were 7 colonies. In addition, there was an increase in the size of bone colonies in the SP-added group. The results indicated that SP had a dose-related osteogenic stimulating effect. The increase in the number and size of bone colonies by SP was probably caused by stimulating stem cell mitosis, osteoprogenitor cell differentiation or osteoblastic activity.

The kitchen appliance known as the "radar oven" generates heat quickly in materials containing water. Protoplasm exposed to the irradiation can thus be denatured. The amount of heat generated is a function of the time of exposure and the intensity of the irradiation, and the size and specific heat of the tissue or organism being irradiated. But docs such heating have applicabiity to histological technique? One of four carcas temperaturea (approximately 60°, 70°, 77°, and 85 C) was generated in anaesthetized, adult hairless mice of both sexes. "Control" animals were not irradiated. Specimens of liver, kidney, lung, and (from males) testis were taken from the five groups; the tissue spedmens were dehydrated in tetrahydrofuran, embedded in paraffin, sectioned at 9 μm, and stained with hematoxylin and eosin. The preparations were suitable for histological examination. Each organ had an optimum temperature for histological fixation under the conditions of this experiment: liver, ∼70°; kidney, ∼77°; lung, ∼77°; and testis, ∼85 C. Heat fixation by microwave irradiation also shows some applicability to electron microscopical studies and to investigations of the blood vascular arrangements of organs.

This article has discussed most of the modalities currently in use for the filling of bony defects. No one modality or combination of methods or materials has yet surfaced as the definitive means of treatment for filling these defects.

The purpose of this in vitro studywas to determine whether there were differences in the number and size of osteogenic and hemopoietic colonies derived from bone marrow stem cells of aged and young adult male Sprague‐Dawley rats. Using a Ficoll‐Paque gradient, stem cells were harvested from aged male rats 18 to 22 months old and young adult males 55 days of age. Single cell suspensions from the red marrow of the long bones were cultured 14 days in vitro and subsequent colonies were assessed by light microscopy for number and size. A computerized histomorphometric linear measuring system was utilized to assess colony area in square millimeters. The results clearly show that young animals have a statistically significant increased cellular potential for osteogenic and hemopoietic colony formation. Cultures from aged animals showed an average formation of 0.45 ± 0.6863 osteogenic colonies while those from younger animals had an average of 3.6 ± 2.3523 osteogenic colonies per 3 million cells plated. Hemopoietic colonies from aged animal cell cultures numbered 5.25 ± 2.2449 while those from the young animals averaged 8.23 ± 3.3601 per 3 million cells plated. The difference in size of the osteogenic and hemopoietic colonies between age groups was not statistically significant. The area of osteogenic colonies derived from aged animals measured 0.1244 ± 0.0891 mm2, while those derived from the young animals averaged 0.1276 ± 0.0518 mm2. Hemopoietic colonies from the aged cells measured 0.0759 ± 0.0514 mm2, while hemopoietic colonies from the young animal cells measured 0.06010 ± 0.0180 mm2. The results of this study may have implications for consideration in the cellular healing aspects of aged versus young individuals. J Periodontol 1996;67:184–196.

Chitosan, with a chemical structuresimilar to hyaluronic acid, has been implicated as a wound healing agent. The purpose of this research was to evaluate the effect of chitosan on Osteoblast differentiation and bone formation in vitro. Mesenchymal stem cells were harvested from fetal Swiss Webster mice calvariae prior to osteoblast differentiation and calcification (12 to 13 days in utero). Stem cells were seeded into 6‐well culture plates at a density of 350,000 cells per well. Using this model, it was possible to quantify the influence of chitosan on osteoprogenitor differentiation and osteogenesis. Experimental wells were pretreated with 200 μl chitosan (2 mg/ml in 0.2% acetic acid vehicle). Control wells were pretreated with 200 μl vehicle (0.2% acetic acid) or remained untreated. Cells were allowed to grow under optimal conditions for 14 days. Cell cultures were fixed with glutaraldehyde and stained with Von Kossa stain to identify bone forming colonies. Positive staining colonies were identified and counted under light microscopy. Histologic cross‐sections of representative positively stained colonies identified osteoblasts and confirmed bone formation. Examination of control wells revealed 3.6 ± 0.6 colonies per well while experimental wells revealed a significantly greater average of 6.2 ± 1.2 colonies per well (P≤ 0.01). Computer‐assisted image analysis of the average area of bone formed by control colonies was 0.34 ± 0.09 (relative units) while that of experimental colonies was 0.39 ± 0.06 (relative units) per average bone forming colony. The difference in mean size (control versus chitosan bone forming colony) was not statistically significant (P= 0.4691). The results of this in vitro experiment suggest that chitosan potentiates the differentiation of osteoprogenitor cells and may facilitate the formation of bone. J Periodontol 1996;67:1170–1175.

A study was made of the weight changes undergone by slices of rat liver, kidney, and other organs immersed in certain fixatives containing chromium. In some experiments the data could be interpreted as indirect measurements of the fixative's ‘effective’ osmotic pressure, or ‘tonicity’, a property which usually differs from the fluid's ‘total’ osmotic pressure. In the case of kidney slices exposed to aqueous potassium dichromate, the rapidly occurring and reproducible responses seem proportional to the fixative concentration; no clear-cut differences were observed with liver slices similarly exposed. Altering the concentration of chromic acid did not affect quantitatively or qualitatively the response patterns of either tissue. Responses of slices to combinations of dichromate and formalin suggest cumulative action of the two moieties. The response patterns to the latter fluids could be modified by the addition of ‘indifferent’ substances such as sucrose.

Compared to other muscular organs, there is very little collagen in the left ventricle of the heart. Only about 1% of the wet weight of the left ventricle is due to collagen (1) and most of this collagen is found in the coronary vessel walls and the valvular apparatus. Although there are only a few collagen fibers among the muscular fibers, it is generally assumed that these collagen fibers exert a large effect upon the passive (or diastolic) compliance of the musculature of the left ventricle (2).Experiments designed to test collagen's contribution to the mechanical properties of the left ventricle have yielded conflicting results. Rabbit hearts incubated in collagenase-containing solutions (1.5 mg/ml) were reported to have increased left ventricular distensibility (3). However, Grimm and White-horn (4) bathed beating hearts with solutions containing from 0.003 to 0.20 mg/ml collagenase and concluded that collagen was not responsible for any diastolic mechanical properties of the heart. Both these experiments were attempts to remove collagen in vitroand both may be criticized: the first cited used dead hearts; the second used levels of enzyme which might have been inadequate. The experimental protocols would have been improved had the collagen been altered in vivobeforehand. A metabolic disease known as “lathyrism” provides a means for altering the collagen beforehand. In many immature laboratory animals, lathyrism can be induced by feeding a lathyrogen such as beta-amino-proprionitrile (BAPN). Lathyritic collagen is weaker than normal and tissues become more extensible (5). The turkey poult is susceptible to lathyrism (6) and its heart is of a size convenient for experimental manipulation. If collagen is important in the passive distensibility characteristics of the left ventricle, and if cardiac collagen is as susceptible to the biochemical lesion as the collagen of other tissues, hearts of lathyritic poults should have markedly altered pre- and postmortem pressure-volume characteristics.

The article discusses the association of one's urge to create art with the development of an enlarged basal ganglia. It mentions that a swollen basal ganglia causes the urge to create art and treatments should be applied directly at the affected areas. The author details the methods of ultra sound vibration and radio therapy that can be used by therapists and medical professionals to shrink basal ganglia, thus controlling one's intense desire to create art.

Several blog posts are presented related to agricultural topics including difference between men and women in agriculture, estate planning and New Year's resolutions.

Presents letters to the editor referencing articles and topics discussed in previous issues. Reviews of two books about Anne Boleyn in the September 17, 2004 issue; Review of the first volume of Isaiah Berlin's letters in the September 3, 2004 issue; Review of "American Memory in Henry James," in September 24, 2004 issue; Others.