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Biomedical subjects

D Daniel

Publications and source records attributed to D Daniel.

At least 19 recordsLinked to original sources
PubMed1991

Structure of (+/-)-3-benzyloxy-2,3,3a,7a-tetrahydrobenzo[b]thiophen-5 (4H)-one 1,1-dioxide.

C15H16O4S, (1), Mr = 292.35, orthorhombic, Pbca, a = 5.9496 (10), b = 11.483 (3), c = 40.262 (7) A, V = 2750.7 (10) A3, Z = 8, Dx = 1.41 g cm-3, mu = 2.340 cm-1, Mo K alpha radiation, lambda = 0.7107 A, F(000) = 1232, T = 198 K, R = 0.0451 for 1703 reflections [Fo greater than or equal to 4 sigma (Fo)]. The two rings are cis-fused with the ring junction torsion angles being -38.2 (3) degrees for C3--C3a--C7a--S1 and -38.4 (4) degrees for C4--C3a--C7a--C7. The thiophene ring assumes the envelope conformation [C3a is 0.590 (3) A from the plane through S1, C2, C3 and C7a] while the cyclohexanone moiety is in the sofa conformation [C3a is 0.530 (3) A from the plane through C4, C5, C6, C7 and C7a].

Crystallization↗
PubMed1990

Structures of two diastereomers of the tetrahydrobenzothiophene moiety of breynolide.

(1) (+/-)-3-Triisopropylsiloxy-2,3,3a,7a-tetrahydrobenzo[b]thiophen -5(4H)-one 1,1-dioxide, C17H30O4SSi, Mr = 358.57, triclinic, P1, a = 7.4383 (14), b = 8.1000 (15), c = 16.895 (3) A, alpha = 80.202 (14), beta = 88.800 (15), gamma = 76.231 (14) degrees, V = 974.0 (3) A3, Z = 2, Dx = 1.22 g cm-3, Mo K alpha, lambda = 0.7107 A, mu = 2.339 cm-1, F(000) = 388, T = 298 K, R = 0.0436 for 3086 reflections [F0 greater than or equal to 4 sigma(F0)]. (2) (+/-)-3-tert-Butyldiphenylsiloxy-2,3,3a,7a-tetrahydrobenzo[b]th iophen- 5(4H)-one 1,1-dioxide, C24H28O4SSi, Mr = 440.63, triclinic, P1, a = 9.113 (2), b = 11.020 (2), c = 12.551 (3) A, alpha = 74.01 (2), beta = 70.83 (2), gamma = 88.70 (2) degrees, V = 1141.4 (4) A3, Z = 2, Dx = 1.28 g cm-3, Mo K alpha, lambda = 0.7107 A, mu = 2.125 cm-1, F(000) = 468, T = 298 K, R = 0.0424 for 4262 reflections [F0 greater than or equal to 4 sigma(F0)]. The two rings are cis-fused with the cyclohexenone ring in the sofa conformation and the tetrahydrothiophene ring in the half-chair conformation for both (1) and (2). However, the bulky siloxy groups assume different orientations in the two compounds. In (1), the triisopropylsiloxy group is equatorial and close intramolecular contacts between H2A and H4B [2.29 (3) A], O11 and C4 [2.934 (3) A] and O9 and C7 [2.979 (3) A] are observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Chemical Phenomena↗
PubMed1989

Structure of a functionalized tetrahydrobenzothiophene.

(+-)-4-(tert-Butyldimethylsiloxy)-3a,4,7,7a-tetrahydrobenzo[b] thiophen -3(2H)-one 1,1-dioxide, C14H24O4SSi, Mr = 316.49, monoclinic, P2(1)/n, a = 7.1431 (7), b = 19.643 (2), c = 12.528 (1) A, beta = 104.810 (8) degrees, V = 1699.4-(3) A3, Z = 4, Dx = 1.24 g cm-3, Mo K alpha radiation, lambda = 0.71073 A, mu = 2.597 cm-1, F(000) = 680, T = 298 K, R = 0.0566 for 2733 reflections [Fo greater than or equal to 4o-(fo)]. The two rings are cisfused with the cyclohexene ring in the half-chair conformation while the thiophene moiety has the envelope conformation. The endocyclic bond angles of the cyclohexene ring are enlarged, especially at the bridgehead C atoms, C3a and C7a, which have angles 116.0 (2) and 116.8 (2)o, respectively. There are several close intramolecular contacts: C3...O11 2.614 (3), O10...O11 3.137 (3), O10...C7 3.073 (4) A. Adjacent molecules related by 1-x, 1-y, 2-z stack so that the carbonyl O and C atoms of one molecule lie directly over the carbonyl C and O atoms of the second molecule. The C...O distance is 3.023 (3) A in this intermolecular interaction.

Organosilicon Compounds↗
PubMed1989

EEG asymmetries may be affected by cranial and brain parenchymal asymmetries.

The plagiocephaly index, an index that reflects an underlying anatomic asymmetry of the brain, was assessed in ten schizophrenic patients and its values were correlated with the lateral distribution of quantitatively evaluated EEG. The correlations between the index and alpha power at F7 were significant, positive for frontal asymmetry (frontal bulging) and negative for occipital flattening. We then studied ten normal subjects in an attempt to illuminate the contribution of several cephalic and cranial variables to the imbalance of alpha-afterdischarges (AD) of VEP recorded at O1-O2. The asymmetry index of AD was computed and correlated with asymmetries of CT-derived measures of occipital bone thickness, occipital lobe width, mastoid area, and sulcal asymmetry (the asymmetry of intraparietal sulcus location from the longitudinal fissure). With the exception of the sulcal variable all measures significantly covaried with alpha AD. These findings caution that it may be important to determine cranial and brain parenchymal asymmetries where brain laterality is pertinent to studies of EEG.

Adolescent↗
PubMed1988

Orientation of the cruciate ligament in the sagittal plane. A method of predicting its length-change with flexion.

We have studied the kinematics of the knee in the sagittal plane, using a four-bar linkage as model, and assuming that a "neutral fibre" in each ligament remains isometric throughout flexion. We devised a computer program to calculate the distance separating any pair of points, one on each bone, for various cruciate attachments at various angles of flexion. The parameters for the linkage in four cadaveric knees were obtained by marking the centre of attachment of the cruciate ligaments with tacks and taking lateral radiographs. The movements of the bones were then calculated, in the computer model, for various attachments of "replacement" ligament fibres, the distance between the attachment sites being plotted against the angle of flexion. It was then possible to define zones around the isometric attachment points within which changes in length would be predictable. Our results show that the position of the femoral sites of attachment of both anterior and posterior cruciate replacement was more critical than that of the tibial attachments.

Adult↗
PubMed1985

Radical wedge resection for ingrown toenail: long-term results.

This paper describes an operation for ingrown toenail that is simple, has a low recurrence rate, leaves patients with an intact, pain-free, cosmetically acceptable nail-bearing toe, and permits the wearing of normal shoes within a short period of time. Among the numerous techniques devised for the treatment of ingrown toenail, no other operation fulfills all of these criteria. It is usual to sacrifice appearance in the hope of cure. During the last 20 years we have adopted a radical wedge resection that has the advantage of resulting in permanent healing and a good-looking toe. After a first series of 67 cases thus treated without a single recurrence, the technique was used in a further series of 339 cases reported here.

Adolescent↗
PubMed1979

Reduction of neglected congenital dislocation of the hip in children over the age of six years.

Thirty-two neglected congenital dislocations of the hip in twenty-two children over the age of six years were treated by traction, open reduction and Chiari osteotomy. In five hips, where prolonged traction failed to bring the femoral heads into the vicinity of the acetabulum, a shortening subtrochanteric osteotomy of the femur was performed. The overall results were good and this regime of treatment is recommended.

Child↗
PubMed1977

Tissue toxicity of antiseptic solutions. A study of rabbit articular and periarticular tissues.

The gross, histologic, and biochemical effects of four commercially available antiseptic solutions on rabbit knee articular and periarticular connective tissues were investigated. Rabbit knee joints were injected with 2.0 cc of either Betadine prep solution, Betadine scrub solution, pHisohex or 3% hexachlorophene. The opposite knees were injected with sterile saline. All animals were injected three times at 48-hour intervals and sacrificed 10 days after the last injection. The solutions containing detergents, Betadine scrub, and pHisohex caused severe gross and histologic damage to articular cartilage, synovia, and muscle. The hexachlorophene loss solution caused moderate histologic damage, but caused articular cartilage ground substance. Betadine prep solution caused only minimal gross and histologic damage, without any biochemical evidence of articular cartilage damage. If antiseptic solutions are to be used in irrigating or packing joint injuries, the use of Betadine prep is recommended.

Animals↗
PubMed1977

Surgical correction of congenital dislocation of the hip in children aged two to six years.

We report on a consecutive series of 68 children, between the ages of two and six years, with 97 neglected dislocated hips. The standard treatment consisted of traction, open reduction and innominate osteotomy. The results were satisfactory in most cases and the number of complications decreased significantly with improved surgical techniques. Additional operations, such as femoral varisation derotation osteotomy or Colonna arthroplasty, were performed only in exceptional cases for the treatment of complications. The treatment of neglected congenital dislocation of the hip after the patient has begun walking is a difficult orthopedic problem and and uniformly good results cannot be expected. Open reduction and innominate osteotomy appear to be the best form of treatment in the age group studied.

Child↗
PubMed1976

Lavage of septic joints in rabbits: effects of chondrolysis.

Septic joints were produced in rabbits which were then treated with systemic procaine penicillin. One group of animals also had surgical lavage at four and seven days after bacterial inoculation. In the infected joints there was a significant loss of hexosamine by five days and of collagen by nine days. Lavage delayed the loss of collagen.

Animals↗
PubMed1975

Compartmental evaluation of osteoarthritis of the knee. A comparative study of available diagnostic modalities.

The distribution and severity of osteoarthritis were investigated in 56 knees by history and physical examination, assessment of knee function, radiography with and without weight-bearing, double-contrast arthrography, and 99mTc-polyphosphate bone imaging. Compartmental involvement (medial, lateral, patellofemoral) was graded independently by 2 or 3 observers for each modality and was correlated with that observed during arthroscopy or direct surgical inspection. The more involved compartments were graded abnormal by all methods. In the less involved compartments, the gamma camera image was most sensitive to pathology, followed by arthrography. The choice of surgical technique and the prognosis depend upon accurate preoperative knowledge of the extent of disease.

Adult↗