Histological observation

Length and size of CNTs seriously affect their cytotoxicities (Sato et al., 2005 Cui et al., 2007). CNTs of 825 nm in length caused stronger inflammation in human acute monocytic leukemia cell line THP-1 than CNTs of 220 nm in length, as shown in Fig. 9.5. However, histological observation as shown in Fig. 9.6, showed that no severe inflammatory response such as necrosis, white cells aggregates, etc. This result indirectly shows that CNTs can cause noninflammatory damage to local tissues. 

In the well-conducted, comprehensive 90-day studies, no treatment-related grossly or histologically observable lesions were found in the lungs, hearts, hematopoietic tissues, or in the skin or eyes of rats and mice dosed by gavage with isophorone (NTP 1986), rats treated with isophorone in the diet... 

Varner JA, Huie C, Horvath W, et al. 1993. Chronic A1F3 administration II. Selected histological observations. Neurosci Res Commun 13 99-104. 

Animals can also be sensitized to chromium compounds. Contact sensitivity was induced in mice by rubbing a solution of 1% potassium dichromate (0.35% chromium(VI)) 50 times on the shaved abdomens. Challenge with potassium dichromate on the ear resulted in significant induction of sensitivity, measured by ear thickness and histologically observed infiltration of nucleophilic leukocytes (Mor et al. 1988). 

Histological observation of shoots formed on internodal segments... 

Histological observations of adventitious shoot initials were performed by light mieroscopy and seanning electron microscopy (SEM) as follows. The internodal segments were fixed in Camoy s fluid... 

Fig. 25 Histological observations at 4 weeks (HE stain, 2x). (a) Negative control (high density polystyrene), (b) Positive control (polyurethane containing 0.75% zinc diethyldithiocaibamate), (c) PAMPS/PDMAAm gel, (d) PAMPS/PAAm gel, (e) BC/PDMAAm gel, (f) BC/gelatin gel. Scale bar is 1 mm. (Reproduced, with permission, from [108])...

In a study of 2-butoxyethanol acetate, Wistar rats and New Zealand white rabbits exposed to a saturated vapor-air mixture of approximately 400 ppm 2-butoxyethanol acetate for 4 hours, and then observed for 14 days after exposure, had no gross hepatic pathological lesions when the animals were sacrificed at the end of 2 weeks (Truhaut et al. 1979). In the same study, no gross or histologically observed hepatic lesions were noted in either rats or rabbits after intermittent exposure (5 days per week, 4 hours per day) to 400 ppm for 1 month or 100 ppm for 10 months. 

Schweikert H, Schnyder UW. 1972a. [Tar-induced acanthosis of the guinea pig nipple. I. Histological observations.] Arch Derm Forsch 243 31-38. (German). 

To answer the question whether heterotopically formed bone, induced by hydroxyapatite, oc- and [3-TCP and biphasic HAp/TCP (BCP), would disappear over time due to the absence of mechanical stresses and whether this heterotopically formed bone would give rise to uncontrolled growth, a long-time investigation over 2.5 years was conducted (Yuan et al., 2001). Porous hydroxyapatite ceramic (HAp), porous biphasic calcium phosphate ceramic (TCP/HAp, BCP), porous a-TCP ceramic and porous P-TCP ceramic were implanted in the dorsal muscles of dog with an observation time of 2.5 years. Histological observation, backscattered scanning electron microscopy observation and histomorphometric analysis were performed on thin non-decalcified sections of retrieved samples. Normal compact bone with bone marrow was found in... 

Negami S (1988) Histological observations on muscle tissue reactions to porous hydroxyapatite sintered bodies in rats. J Japan Orthop Assoc 62 85-94... 

Sarkar MR, Wachter N, Patka P, Kinzl L (2001) First histological observations on the incorporation of a novel calcium phosphate bone substitute material in human cancellous bone. J Biomed Mater Res 58 329-334... 

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