callus

[kal´us]

1. localized hyperplasia of the horny layer of the epidermis due to pressure or friction.

2. an unorganized network of woven bone formed about the ends of a broken bone; it is absorbed as repair is completed (provisional callus), and ultimately replaced by true bone (definitive callus).

A fracture with callus formation (arrow) is demonstrated corresponding to the base of the second metatarsal. From Thrall and Ziessman, 2001.

cal·lus

(kal'ŭs), Avoid substituting the adjective callous for this noun. Avoid substituting the nonword calloused for the past participle callused.

1. Synonym(s): callosity

2. A composite mass of tissue that forms at a fracture site to establish continuity between the bone ends; it is composed initially of uncallused fibrous tissue and cartilage, and ultimately of bone. Synonym(s): fracture callus

[L. hard skin]

Farlex Partner Medical Dictionary © Farlex 2012

callus

(kăl′əs)

n. pl. cal·luses

a. A localized thickening and enlargement of the horny layer of the skin. Also called callosity.

b. The hard bony tissue that develops around the ends of a fractured bone during healing.

intr.v. cal·lused, cal·lusing, cal·luses

To form or develop such hardened tissue. See Usage Note at callous.

callus

Botany
Undifferentiated plant tissue produced at wound edge, callus tissue can be grown in vitro and induced to differentiate by varying the ratio of the hormones auxin and cytokinin in the medium.

Dermatology
Callosity, tyloma—A focus of hyperkeratotic skin secondary to repeated friction or pressure.

Orthopaedics
A mass of indurated bony trabeculae and cartilage formed by osteoblasts early in healing fractures.

Podiatry
A focus of indurated hyperkeratotic skin with a smooth centre, which is usually avascular, caused by rubbing or pressure; typically seen on the plantar aspect beneath the metatarsal head, as well as on the heel and Achilles tendon.

Aetiology
Increased intermittent pressure on the skin; abnormal varus or valgus of foot leading to uneven weight distribution; local bone defect (plantar flexed ray, heel spur), long metatarsal, extrinsic pressure (improper footwear); surgical scars or lacerations.

Management
Trimming of the hyperkeratosis to the central core, soaking (e.g., epsom salts), and shaved regularly; to redistribute weight-bearing, a full-sole orthotic, footwear change and a metatarsal pad or hammer-toe crest pad if needed.

Prevention
Properly fitted shoes.

callus

Callosity, tyloma Dermatology Localized hyperkeratosis of skin 2º to repeated friction or pressure Orthopedics A mass of indurated bony trabeculae and cartilage formed by osteoblasts early in healing fractures

cal·lus

(kal'ŭs)

1. Synonym(s): callosity.

2. A composite mass of tissue that forms at a fracture site to establish continuity between the bone ends; it is composed initially of uncallused fibrous tissue and cartilage, and ultimately of bone.

Medical Dictionary for the Health Professions and Nursing © Farlex 2012

callus

1. A collection of partly calcified tissue, formed in the blood clot around the site of a healing fracture. Callus is readily visible on X-ray and indicates that healing is under way.

2. A skin thickening (see CALLOSITY).

Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005

callus

a mass of immature plant cells which can differentiate into mature tissues, depending upon the relative concentrations of plant growth hormones present. Callus can develop from EXPLANTS in laboratory tissue culture experiments but also occurs naturally at the end of cut or wounded surfaces of shoots and roots.

Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005

Callus

Thickened skin due to chronic rubbing or irritation.

Mentioned in: Lichen Simplex Chronicus

cal·lus

(kal'ŭs)

1. Synonym(s): callosity.

2. A composite mass of tissue that forms at a fracture site to establish continuity between the bone ends.

Medical Dictionary for the Dental Professions © Farlex 2012

Mentioned in

References in periodicals archive

People with nerve damage or poor blood circulation to the feet -- from diabetes or other medical conditions -- should see a foot doctor regularly and, if needed, have calluses trimmed, Andersen said.

Why Your Foot Calluses Might Be Good for You

The highest mean SV (%) was detected in calluses (n = 35) grown on medium supplemented by Au NPs (Mlo SV = 14.68 [+ or -] 0.98; Pme3 SV = 12.07 [+ or -] 0.87), while in calluses (n = 35) grown on medium supplemented by Ag NPs (Mlo SV = 12.01 [+ or -] 0.43; Pme3 SV = 10.04 [+ or -] 0.46) it was lower.

Case Study of Somaclonal Variation in Resistance Genes Mlo and Pme3 in Flaxseed (Linum usitatissimum L.) Induced by Nanoparticles

The distribution of plantar calluses varies across the metatarsal heads, with the second metatarsal head being the most common site, see Table 1.

Hyperkeratosis of the foot: part 2

When callogenic responses were studied in MS +2, 4- D [0.5 mg/l], the 2.0 mm sized calluses were separated and then sub-cultured in MS media with three combinations of BAP and 2, 4-D [1.0 mg/l BAP + 0.5 mg/l 2, 4- D; 1.5 mg/l BAP + 0.5 mg/l 2, 4- D; 2 mg/l BAP+ 1.0 mg/l 2, 4- D].

A study on callus induction of Ipomoea mauritiana: an Ayurvedic medicinal plant

It is explained by closed adjoint of the massive periosteal and parosteal calluses to the soft tissues, i.e.

Clinical features the diaphyseal refractures of the forearm in children

When 60-days-old calluses were shifted to the same medium containing various NaCl levels (0-160 mM), variation in callus morphology of both the cultivars was observed.

EFFECT OF NaCl STRESS ON CALLUS MORPHOLOGY AND GROWTH OF SUGARCANE CALLUS CULTURES (cv. SPF 234 AND cv. HSF 240)

The initial calluses were induced from internodes and leaves of two varieties, taken from vitroplants of four to five weeks of growth.

Effect of 2.4-D Phytohormone on neoformation of somaclonal variants in Solanum tuberosum L

It has been reported that high concentrations of cefotaxime, carbenicillin and augmentin, may reduce the regenerability of rice calluses, as they resemble auxins in their structure, and in combination with 2,4-dichlorophenoxyacetic acid (2,4-D) may cause loss in regeneration potential (Okkels and Pederson, 1988).

Antibioticos beta-lactamicos efectivos para eliminar el Agrobacterium tumefaciens en callos de arroz indica

Obvious pains like Socha's, or merely visible imperfections like black toenails or calluses, often indicate imbalances that can lead to injury.

What Your Feet Say About Your Health

The appearance of the calluses varied with all the three explant types and media.

Regeneracion de plantas a partir de cultivos de callos de Vitex trifolia (Lamiales: Lamiaceae): una planta medicinal potencial