Biomedical subjects

B Fink

Publications and source records attributed to B Fink.

95 records · Page 6Linked to original sources

PubMedDate not supplied

Second to fourth digit ratio, body mass index, waist-to-hip ratio, and waist-to-chest ratio: their relationships in heterosexual men and women.

BACKGROUND: Prenatal sex steroids have been broadly discussed in terms of their possible effect on brain differentiation, whereas pubertal/adult sex hormones are thought to be the main regulators of sexually dimorphic physical features in males and females. Assessing prenatal steroid exposure has previously been difficult but evidence now suggests that finger length ratio may provide a 'window' into prenatal hormone exposure. The length of the second digit (the index finger) relative to the length of the fourth digit (the ring finger) is sexually dimorphic as males have a lower second to fourth digit ratio (2D:4D). The sexual dimorphism is determined as early as the 14th week of fetal life, and remains unchanged at puberty. There is evidence that sex differences in 2D:4D arise from in utero concentrations of sex steroids, with a low 2D:4D (male typical ratio) being positively related to prenatal testosterone, while a high 2D:4D (female typical ratio) is positively associated with prenatal oestrogen. AIM: The studied aimed to determine whether, and to what extent, adult sexually dimorphic physical traits, which are largely determined at puberty, relate to traits that are largely determined in utero. This work examined the relationship between three sexually dimorphic traits--body mass index (BMI), waist-to-hip ratio (WHR) and waist-to-chest ratio (WCR)--and digit ratio. PARTICIPANTS AND METHODS: BMI, WHR and WCR were assessed in 30 heterosexual male and 50 heterosexual female participants by recording their body height, weight, and measuring their waist, hip and chest circumference. Digit lengths of the second and fourth fingers were measured from photocopies of the ventral surface of the hand and by actual finger measurements. RESULTS: Digit ratio was found to be significantly lower in men than in women. Significant negative correlations were found between female's left and right hand 2D:4D, waist and hip circumference, and WCR. In males, BMI was found to be positively related to digit ratio but remained significant only for left hand 2D:4D. Generally, the relationships were stronger for females than for males. Although not all relationships were found to be significant, they were in accord with our predictions. CONCLUSION: In addition to an activational effect of sex hormones at puberty, the present data suggest an early organizational effect of sex hormones through the association between indices of female body shape, male BMI, and human finger length patterns.

Adult↗

PubMedDate not supplied

Behavior of tendons during lower-leg lengthening in dogs using the Ilizarov method.

Twenty-two dogs were provided with a circular fixator. Lengthening of the right lower leg by 2.5 cm was performed on 18 dogs 5 days after tibial osteotomy using a distraction rate of 0.5 mm, twice per day. Nine dogs with leg lengthening and two dogs of the control group without leg lengthening were sacrificed at the end of the distraction phase of 25 days and the remaining dogs after another 25 days. Post mortem, the tendons of the tibialis anterior, extensor digitorum longus, peroneus longus, and the Achilles tendon were taken from the operated-on right side and the left nonoperated-on control side and were analyzed histologically. The control group showed no histologic changes in the tendons of either side nor in those of the unlengthened left side of the operated-on dogs. Thirty-three tendons (41%) of dogs with leg lengthening were seen to have undergone histomorphological changes. An increase of the peritendinous connective tissue was seen, combined with chronic inflammatory cell infiltration in the tendons and/or the epitendinous tissues, edema, tendon fragmentation, necrosis, scarring of the tendons with dystrophic calcification and/or ossification, and broadening of the tenosynovial sheath. Furthermore, signs of histoneogenesis with growth in the tendons were found. Degenerative changes occurred far more often in the tendons of the ventral side of the lower leg and a slight pes equinus was regularly observed in the lengthened extremity. Therefore, pes equinus prevention and physiotherapy are important in the therapeutic use of lower-leg lengthening to minimize possible stress-induced damage of the ventral tendons.

Animals↗

PubMedDate not supplied

Behavior of blood vessels during lower-leg lengthening using the Ilizarov method.

Using a ring fixator, lengthening of the right lower leg by 2.5 cm at a distraction rate of 2 x 0.5 mm per day was performed in 24 beagle dogs. After a postoperative latency period of 5 days and a distraction phase of 25 days, half the dogs were killed (30-day group). The remaining half were killed after a second interval of 25 days (55-day group). After the experiment, the anterior tibialis artery and vein with their supporting vessels, as well as the lesser saphenous vein of both the lengthened right side and the control side were excised and examined histologically, histomorphometrically, and electron microcopically. No morphologic changes of the vascular walls and no increase of collagenous or elastic fibers could be found. The histomorphometric evaluations showed a significant increase in the number of vasa vasorum in the dogs of both the 30- and 55-day groups. No significant difference in thickness of the vascular wall, tunica media, and adventitia could be observed between the lengthened and the control side in both dog groups. It seems that blood vessels can adapt to continuous tension during callus distraction without suffering structural damage and are the least limiting factor concerning distraction speed, distraction rhythm, and distraction length during callus distraction.

Animals↗

PubMedDate not supplied

Time course of osteocalcin, bone-specific alkaline phosphatase, and C-terminal procollagen peptide during callus distraction.

This study involved 15 patients who were undergoing extremity lengthening by callus distraction. Blood samples and radiographs of the callus distraction segment were obtained before surgery, every 2 weeks during the distraction phase, and every 4 weeks between the end of distraction and removal of the fixator. A digital radiograph analysis system was used to determine the radiographic density of the callus distraction segments. In addition, the serum parameters osteocalcin, bone-specific alkaline phosphatase, and C-terminal procollagen peptide (PICP) were evaluated. The radiographic density was constant during the distraction phase, but increased logarithmically during the consolidation period. Similar kinetics were observed for osteocalcin, with an average coefficient of correlation between these two parameters of 0.66+/-0.15. PICP levels rose rapidly after surgery and increased further during the consolidation period. Serum levels of bone-specific alkaline phosphatase were not uniform between patients, and there was no correlation to the kinetics of radiographic density or the other serum parameters. The similarity between radiographic density and osteocalcin kinetics, as well as the rapid postoperative increase in PICP, imply that further information may be obtained about osteoneogenesis from the study of these two serum parameters.

Adolescent↗

PubMedDate not supplied

Shoulder arthrodesis in pediatric patients.

Shoulder arthrodesis was performed in 17 pediatric patients. Diagnoses included birth-related brachial plexus palsy (six patients), posttraumatic palsy (three patients), and residual paralysis after poliomyelitis (eight patients). The position of fusion was not as important as the stability gained by the patient. Excessive abduction or forward flexion should be avoided, however, because this can be cosmetically displeasing to patients.

Adolescent↗