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Biomedical subjects

D Ring

Publications and source records attributed to D Ring.

At least 55 records · Page 3Linked to original sources
PubMed1996

Operative fixation of Monteggia fractures in children.

We reviewed 36 consecutive patients with Monteggia fracture-dislocations of the forearm; 28 had been treated within 24 hours and 8 had been referred a week or more after the initial injury with persisting or recurrent dislocation of the proximal radio-ulnar joint after treatment elsewhere. We treated 15 of the 16 complete fractures and 3 of the 11 incomplete fractures of the ulna by operative fixation. All the early fractures and six of the eight late referrals had good or excellent results. The two poor results were in patients with malalignment and dislocation of the radial head persisting for at least two weeks before definitive treatment. A good outcome after a Monteggia injury in a child requires early diagnosis and prompt, stable, anatomical reduction of the ulnar fracture. In our experience, selective operative fixation of unstable fractures provides reliable reduction and causes few complications.

Adolescent↗
PubMed1996

Management of fractures and dislocations of the elbow in children.

Elbow injuries are common in children. The keys to a good outcome include timely, accurate characterization of the injury, stable anatomic reduction, utilization of closed treatment methods whenever possible and limited soft tissue dissection when operative treatment is required. Awareness of the developmental physeal anatomy of the elbow, common injury patterns and potential complications are essential in the management of these injuries. This review presents a practical approach to the management of elbow traumatic injury in the child, providing guidelines for evaluation and treatment for the less common pediatric elbow injuries.

Child↗
PubMed1995

Vertebral osteomyelitis after blunt traumatic esophageal rupture.

STUDY DESIGN: This is a report of a case. OBJECTIVE: To document the occurrence and characteristics of vertebral osteomyelitis after blunt traumatic esophageal perforation. SUMMARY OF BACKGROUND DATA: Vertebral osteomyelitis in association with esophageal rupture has been reported after penetrating, but not blunt traumatic injuries. METHODS: All of the listed authors were involved in the care of this patient. All medical records, laboratory and radiologic investigations, and related literature were reviewed. RESULTS: The mixture of oral aerobic and anaerobic organisms inoculated into vertebral bone after blunt traumatic esophageal perforation caused a rapidly destructive vertebral osteomyelitis reminiscent of bite-wound injuries of the hand. CONCLUSIONS: Awareness of the occurrence of blunt traumatic esophageal perforation and the associated risk of vertebral osteomyelitis may lead to earlier detection and treatment of these infections.

Esophagus↗
PubMed1995

The complications and difficulties of management of nonunion in the severely obese.

Operative fixation of 22 nonunited fractures was undertaken in 21 obese patients. Eleven patients were women and 10 were men, with an average age of 46.3 years (range 25-74). The average body mass index in this group of patients was 37.9 kg/m2 (range 33.2-57.1). Two patients were classified as morbidly obese and 19 as severely obese. The management of these patients proved to be fraught with difficulties related to their obesity. There were a number of occurrences believed to be related to poorly protective positioning and prolonged ischemic pressure under the patient's body weight during the administration of anesthetic, including a peroneal compartment syndrome, a gluteal compartment syndrome with sciatic nerve palsy, bilateral brachial plexus stretch injuries, an anterior interosseous nerve palsy, and the postoperative development of a patch of scalp alopecia. There were two wound separations and no episodes of thromboembolic disease. Sixteen nonunited fractures healed after the index procedure at an average time to healing of 5.6 months (range 2-14). Five nonunited fractures required a second procedure to gain union [average total time to healing 17 months (range 10-31)]. A single fracture remains ununited. Awareness of the unique technical demands and operative and anesthetic risks encountered when undertaking an operative procedure in a severely obese patient is imperative for the safe and successful treatment of orthopaedic surgical problems in these patients.

Adult↗
PubMed1994

Vertebral artery location in relation to the vertebral body as determined by two-dimensional computed tomography evaluation.

STUDY DESIGN: This study analyzed the precise two-dimensional location of the vertebral artery within cervical vertebrae as determined by measurements obtained from axial computed tomographic images of the cervical spine. OBJECTIVE: To determine the margin of safety necessary to avoid vertebral artery laceration during central decompression and lateral nerve root decompression for cervical spinal stenosis. SUMMARY OF BACKGROUND DATA: Laceration of the vertebral artery is a rare but potentially catastrophic complication of anterior decompressive surgery of the cervical spine. METHODS: The mean, standard deviation, and 95% confidence interval of the mean of measurements localizing the vertebral artery within the vertebral body were calculated from 50 transaxial computed tomography images of each of the second through sixth cervical vertebrae. RESULTS: Both the mean interforaminal distance (from 25.90 +/- 1.89 mm at C3 to 29.30 +/- 2.70 mm at C6) and the average distance of the posterior border of the foramen transversarium from the ventral border of the spinal canal (from 2.16 +/- 1.18 mm at C3 to 3.53 +/- 1.56 mm at C6) increased from C3 to C6. CONCLUSIONS: According to our measurements, the risk of vertebral artery laceration is greater at more cephalad vertebrae during lateral extension of central decompressive procedures and lateral nerve root decompression. Because of the variability of these parameters between individuals, accurate individual preoperative localization of the vertebral arteries is recommended.

Adolescent↗
PubMed1994

Kinetic parameters of the translocation of bacteriophage T4 gene 41 protein helicase on single-stranded DNA.

The bacteriophage T4 gene 41 helicase protein (gp41) carries a single-stranded DNA-dependent ATPase activity that is essential to its helicase activity. This ATPase activity can be stimulated by a wide variety of single-stranded DNA cofactors, including homo-oligomers and homopolymers 8 to approximately 10,000 nucleotide residues in length, and by natural single-stranded DNA, such as bacteriophage M13 DNA. The steady-state ATPase activity of gp41 on single-stranded homopolymeric cofactors is dependent on the length of the cofactor, in that the kinetic parameters Vmax and K(act) (or KmDNA) have a characteristic length dependence. Vmax values for different DNA lengths show a hyperbolic dependence on DNA length, while K(act) values are independent of DNA lengths exceeding approximately 20 nucleotide residues. Use of the detailed theoretical analysis developed in the preceding paper reveals that: (1) these results support the earlier proposal that gp41 translocates on single-stranded DNA in an ATP-dependent manner; (2) translocation is undirectional; (3) translocation is processive to an extent that depends on the base composition of the DNA employed, with the average distance translocated per binding event ranging from 60 to 700 nucleotide residues; and (4) the detailed translocation mechanism of gp41 includes an obligatory slow step before or after the ATP-driven translocation process. Defined lengths of natural and homopolymer single-stranded DNA have also been created as gaps of known length distribution between clusters of gene 32 protein (gp32) bound along long single-stranded DNA molecules. ATPase data obtained with cofactors of this type also show unidirectional ATP-driven translocation of gp41 on both natural and homopolymeric single-stranded DNA. Direct binding studies of gp41 to short dT oligomers reveal two further features of the interaction of gp41 to single-stranded DNA: (1) nucleoside triphosphate binding is necessary for the formation of stable gp41-ssDNA complexes; and (2) the DNA binding site size of gp41 is between 12 and 20 nucleotide residues per protein monomer. Possible translocation mechanisms for gp41 are discussed within the context of these results.

Adenosine Triphosphatases↗
PubMed1994

Acute calcific retropharyngeal tendinitis. Clinical presentation and pathological characterization.

Acute calcific retropharyngeal tendinitis is an underrecognized cause of pain and stiffness in the neck associated with odynophagia and retropharyngeal soft-tissue swelling. We report on five patients in whom an initial misdiagnosis of this entity as a retropharyngeal or nasopharyngeal abscess, a neoplasm, or a fracture-dislocation of the cervical spine led to interventions such as admission to the hospital and parenteral administration of antibiotics. An open biopsy was performed in one patient because of a suspected neoplasm. Evaluation of the tissue specimen with routine and polarized light microscopy, scanning electron microscopy, and energy-dispersive spectrometry demonstrated a foreign-body inflammatory response to deposited crystals of hydroxyapatite. In all five patients, the correct diagnosis was established only after retrospective review of the radiographic studies by a physician who was familiar with acute calcific retropharyngeal tendinitis. The computed tomographic findings of acute calcific retropharyngeal tendinitis are distinctive and consist of prevertebral calcification localized to the insertion of an edematous tendon of the longus colli muscle. Symptomatic relief was provided with anti-inflammatory and analgesic medications. The symptoms resolved, without sequelae, within one to two weeks for all of the patients. We hope that an increased awareness of hydroxyapatite deposition in the tendon of the longus colli muscle will result in improved early diagnosis of acute calcific retropharyngeal tendinitis.

Abscess↗
PubMed1989

Differential induction by interferons of major histocompatibility complex-encoded and non-major histocompatibility complex-encoded antigens in human breast and ovarian carcinoma cell lines.

Treatment of cancer cells with interferons can modulate expression of cell surface antigens, particularly those of the major histocompatibility complex (MHC). To examine the effect of recombinant gamma- and alpha-interferons on expression of non-MHC antigens, murine monoclonal antibodies have been used to quantitate 14 distinct tumor-associated cell surface antigens from five breast cancer cell lines and five ovarian cancer cell lines using a live cell radioimmunoassay. Both Class I and Class II MHC antigens could be augmented or induced with gamma-interferon. Significantly increased expression of MHC antigens was observed in nine of 10 cell lines with induction indices as high as 11-fold. When 17 non-MHC epitopes were measured on 10 cell lines, minimal (1.3-2.7-fold) induction was observed in 10 of the 170 instances evaluated. Expression of only two epitopes, 2G3 and 735B11, was increased on more than one cell line. On six cell lines expression of non-MHC epitopes could not be increased. Consequently, among many different cell surface determinants, interferons produced a highly selective augmentation or induction of MHC antigens, whereas augmentation or induction of other tumor-associated antigens was apparently restricted to a few epitopes.

Antigens, Neoplasm↗
PubMed1989

Heterogeneity of antigen expression in benign and malignant breast and ovarian epithelial cells.

Expression of II distinct antigen families has been studied in normal and malignant epithelial cells from breast and ovary by avidin-biotin immunoperoxidase staining of frozen tissue sections. Each of the antigens was expressed in a fraction of the normal and malignant breast tissues from different individuals. Among breast and ovarian cancers, a similar fraction of tumors expressed each of the determinants. An epitope on a 42-kDa glycoprotein was expressed significantly more often by ovarian carcinomas than by benign ovarian epithelium. Several determinants on 66-, 240-kDa or high-molecular-weight proteins or glycoproteins were expressed significantly more often on benign breast epithelium than on normal ovarian epithelium. Substantial heterogeneity in antigen expression was observed among different tumor specimens. Each of 14 epithelial ovarian cancers expressed a distinctive combination of antigens. Among 18 breast cancers, 16 distinct antigenic phenotypes were observed. Interestingly, comparable heterogeneity was observed in the expression of epitopes on benign breast and ovarian epithelium, compatible with the possibility that the monoclonal reagents recognized polymorphic determinants. Substantial variations in antigen expression were also observed among cells within each neoplasm. However, when antibodies against 5 different determinants were used in combination, a majority of cells could be stained intensely in all 13 breast carcinomas tested and more than 95% of tumor cells could be stained in 10 of the 13.

Antigens, Neoplasm↗
PubMed1989

[Rectal examination during labor--tradition or compelling necessity?].

6,639 consecutive deliveries are followed up with respect to the course of puerperium. All these patients were examined during delivery vaginally. Febrile temperatures sub partu were to be stated in 1.1% and post partum in 2.0%. Subfebrile temperatures within the first 7 days of puerperium were to be seen in 7.0%, neonatal infections in 0.5%. The pro and contra of vaginal versus rectal investigation are discussed. The use of an emulsion containing chlorhexidine an antiseptic gliding substance is recommended for obstetrical examinations before and during labour.

Bacterial Infections↗
PubMed1989

[Ectopic pregnancy--still a challenge in gynecology. A contribution to diagnosis and therapy].

The diagnostic and therapeutic management in 80 cases with ectopic pregnancy is analysed. Only in 36 cases (45%) there was an accordance of installation diagnosis with the intraoperative status. 44 patients (55%) were suspicious to suffer from acute pelvic inflammatory disease, abortion or irregular uterine bleedings. Only in 28 cases (35%) the clinical symptomatology was so characteristic for ectopic pregnancy that operation had been performed without any other diagnostic procedures. In 34 cases (43%) a laparoscopy was necessary to get the correct diagnosis. In all the other 18 patients (22%) the indication for operation was made by punction of the cul-de-sac, curettage, and/or ultrasound. Because of an increased blood loss more than 500 ml an intra- or postoperative blood transfusion was necessary in about 1/3 of all treated patients. In 32% it was possible to preserve the fallopian tube. The corresponding operative procedure consisted of salpingotomy and manual expression of tubal pregnancy. Local vasoconstrictive acting substances are recommended. If there are hints at an ectopic pregnancy by histologic examination of tissue got by curettage quick and well-organized management is necessary to use the possibility of conservative operation-procedures. Histologic examination of all abortion tissue is requested.

Adolescent↗
PubMed1989

Effector characteristics of the IgG3 murine monoclonal antibody 113F1.

Successful immunotherapy with unconjugated murine monoclonal antibodies (MAbs) is likely to require antibodies with potent effector characteristics such as antibody-dependent cellular cytotoxicity (ADCC). The newly developed IgG3 isotype antibody, 113F1, binds to a target antigen present in high copy number on SK-Br-3 cell surfaces. 113F1 does not appear to participate in complement-mediated cytotoxicity, but is a potent mediator of ADCC by human monocytes directed against a variety of malignant cell lines expressing 113F1's target antigen. Although recombinant interleukin-2 (rIL-2) promotes nonspecific monocyte cytotoxicity, preincubation with this cytokine has no effect on monocyte ADCC in our system. 113F1 promotes ADCC by nonadherent cells expressing lymphokine-activated killer (LAK) activity following incubation of these cells in rIL-2. These latter effects are abrogated by Fc receptor blockade prior to addition of 113F1. 113F1 is a more potent mediator of ADCC by monocytes or LAK cells than is 17-1A, an extensively tested unconjugated murine IgG2a isotope MAb. These data suggest that unconjugated 113F1 MAb immunotherapy trials should investigate treatment with the MAb alone. In addition, 113F1 could be administered with rIL-2, either alone or supplemented with infusions of autologous LAK cells.

Animals↗
PubMed1988

[Preventive use of iron in pregnancy--a luxury or a necessity?].

In an exploratory study 128 healthy gravidae were given 0.114 g of iron daily from the 14th week of pregnancy until birth. Hematologically and clinically important parameters during pregnancy, birth, and puerperium were compared with an untreated control group of 115 gravidae. Following iron prophylaxis, hemoglobin concentration, hematocrit, and erythrocyte count were significantly higher at the time of birth; however, obstetrically significant parameters were unaffected. In view of the low incidence of anaemia during pregnancy and birth, as well as the completeness of the prenatal care system, general iron prophylaxis is unnecessary. High-risk pregnancies are an exception to this rule. The high incidence of anaemia early in puerperium justifies adequate, i.e., high-dose, oral iron therapy from the first day of the first week of confinement on wards.

Anemia, Hypochromic↗
PubMed1988

[The use of a double balloon catheter in the topical extra-amniotic administration of prostaglandin F2alpha gel in indicated labor induction and cervix incompetence].

Using a self-made double-balloon-catheter the instillation of 2.5 mg Prostaglandin F2 alpha into the extraovular chorio-decidual space was down 46 times in 42 late pregnant women. The indication was the unripe cervix uteri in case of urgent parturition. This method is more effective than the pericervical and endocervical application, respectively. Under continuous supervision using external CTG there were neither complications in fetus nor in the mother.

Catheterization↗
PubMed1988

[Postpartum curettage--is it always indicated?].

Within five years (1982-1986) there were in the Dept. Obstet. Gynec., Main Hospital of Suhl 382 curettements after 7,462 term deriveries (greater than 37. week of pregnancy). This is a frequency of 5.2%. Only in 25% there was a histologic confirmation of placental tissue. Discussion about possibilities to reduce the frequency of such curettements post partum without neglecting necessary interferences.

Chorionic Villi↗
PubMed1985

Evaluation of monoclonal antibodies for the development of breast cancer immunotoxins.

Eighty-five antibodies recognizing breast cancer-selective antigens were conjugated to ricin toxin A-chain using a disulfide linkage. The cytotoxicities of the resulting immunotoxins were determined on breast cancer cells and normal human fibroblasts. Twenty-four antibodies formed immunotoxins that were toxic to at least one breast cancer cell line at concentrations of 10 nM or less but were nontoxic to human fibroblast lines used as negative controls. Some of the breast tumor-selective immunotoxins were as toxic as a conjugate between monoclonal anti-transferrin receptor and ricin toxin A-chain (50% inhibition of cellular protein synthesis at approximately 0.1 nM). Another set of four immunotoxins were indiscriminately toxic to human breast tumor cell lines, two human fibroblast cell lines, and a human lymphoblastoid line. Several of the antibodies the toxin conjugates of which specifically killed breast cancer cell lines may be useful in cancer therapy, since they show a wide range of binding to individual breast tumors and cell lines and a limited range of binding to normal tissue types.

Antibodies, Monoclonal↗