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Biomedical subjects

J E Freeman

Publications and source records attributed to J E Freeman.

At least 37 records · Page 2Linked to original sources
PubMed1993

Surgical techniques in partial anomalous pulmonary veins to the superior vena cava.

Over a 12-year period, 40 patients underwent repair of partial anomalous pulmonary veins (PAPV) draining to the superior vena cava (SVC) proximal to the sinus node. Mean age was 6 +/- 2 years. In all patients, the SVC was cannulated superior to the PAPV, which were baffled with pericardium to left atrium. Six patients had associated defects repaired. In 18 patients (group I), an incision was made at the crest of the right atrial appendage (RAA) and extended upward through the sinus node and to the SVC. After rerouting of the PAPV, the SVC was enlarged using the RAA (atriocavoplasty). In 17 patients (group II), rerouting of the PAPV was accomplished through a right atriotomy. Superior vena caval enlargement was not done. Drainage of the PAPV was close to the right atrium in 14 patients (low) and to the azygos vein (high) in 3. In 5 patients (group III), an incision was made on the SVC and RAA sparing the sinus node. After rerouting of the PAPV, the RAA was anastomosed to the SVC (end to side), providing another outlet for SVC flow. There was no early or late death. Two patients (10%) in group I had late sinus bradycardia. Obstruction of the SVC and PAPV developed in 1 patient in group II with high drainage. Intermittent complete heart block developed in 1 patient in group III who also had ventricular septal defect repair. We conclude that atriocavoplasty is effective for rerouting of the PAPV and enlarging the SVC, but may predispose to sinus node disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Right ventricle-to-aorta conduit in pulmonary atresia with intact ventricular septum and coronary sinusoids.

A 20-month-old girl with pulmonary atresia, intact ventricular septum, and ventriculocoronary connections underwent successful interposition of a right ventricle-to-aorta conduit and Fontan operation. The patient initially had a modified Blalock-Taussig shunt at birth and subsequently a bidirectional Glenn shunt at 8 months of age. After Fontan and right ventricle-to-aorta conduit placement, the suprasystemic right ventricular pressure dropped to systemic levels without causing myocardial injury. Additionally, the right ventricular cavity enlarged. We believe that the use of a right ventricle-to-aorta conduit should provide a valuable alternative and improve the outlook of certain patients with pulmonary atresia, intact ventricular septum, and ventriculocoronary connections.

Cardiac Surgical Procedures↗
PubMed1993

Obligatory Glenn shunt in fenestrated Fontan.

Five high-risk patients undergoing the Fontan operation required large fenestration (1 cm) because of high central venous pressure and low cardiac output. Because of major arterial desaturation, obligatory Glenn shunts were performed. Three patients had pulmonary atresia, 1 had tricuspid atresia 1-B, and the fifth had single ventricle with subaortic stenosis. The age ranged from 16 to 40 months (mean age, 25 +/- 9 months) and weight from 7.9 to 14.6 kg (mean weight, 11 +/- 2 kg). One patient had single and 3 had bilateral subclavian pulmonary artery shunts. The fifth patient had pulmonary artery banding and coarctation repair followed by an aortopulmonary window and central shunt. The first 2 patients repeatedly had to go back on cardiopulmonary bypass for a larger fenestration and subsequently had an obligatory Glenn shunt because of arterial desaturation. The last 3 patients had planned obligatory Glenn shunt and large fenestration. The first patient died on the second postoperative day of a combination of prolonged operation, repeated cardiopulmonary bypass, and periods of hemodynamic instability. Three patients had closure of the adjustable fenestration under local anesthesia at 4, 5, and 8 weeks postoperatively. The last patient is awaiting closure. We believe that in certain high-risk patients, a large fenestration combined with an obligatory Glenn shunt should be considered to minimize repeated cardiopulmonary bypass and urgent tightening or closure of fenestration in the immediate postoperative period.

Arteriovenous Shunt, Surgical↗
PubMed1992

cDNA sequence, deduced amino acid sequence, predicted gene structure and chemical regulation of mouse Cyp2e1.

The cDNA encoding the mouse Cyp2e1 protein has been isolated and sequenced, and shown to share 92%, 79%, 80% and 79% sequence similarity over the coding region with rat, human, rabbit 1 and rabbit 2 CYP2E1 cDNA sequences respectively. The predicted Cyp2e1 protein contains 493 amino acids, with a molecular mass of 56781 Da. The protein contains many features common to other cytochrome P450s, including a potentially phosphorylatable serine residue at position 129 within a canonical cyclic AMP-dependent protein kinase site. Southern blot analysis of genomic DNA prepared from C57BL/6 and DBA/2N mice suggests the presence of only a single Cyp2e1 gene. The Cyp2e1 gene was isolated and its organization was established by PCR using oligonucleotides to its predicted intron/exon boundaries. These results showed that the mouse Cyp2e1 gene is approx. 11,000 bp in length and has a similar structure to the human and rat CYP2E1 genes. Cyp2e1 protein expression was studied in a variety of tissues and a sexual dimorphism in its levels in some tissues was noted. Acetone treatment induced the Cyp2e1 protein in all of the tissues studied in both sexes, but this Cyp2e1 protein induction was not accompanied by an increase in Cyp2e1 mRNA levels. Indeed, mRNA levels were seen to be decreased on treatment, suggesting that acetone administration affects either mRNA translation efficiency or protein stability. Of a wide range of drugs known to modify other cytochrome P450 levels only diethylnitrosamine had a significant effect on Cyp2e1, causing a decrease in protein levels.

Amino Acid Sequence↗
PubMed1992

Dipeptidase-C in Drosophila melanogaster: genetic, ontogenetic, and tissue-specific variation.

Dip-A, Dip-B, and Dip-C constitute structural genes for three peptidic enzymes in Drosophila melanogaster distinct from the leucine aminopeptidases. Their ontogenetic and tissue distributions of activities suggest the involvement of these enzymes in a general metabolic role, such as the regulation of amino acid and oligopeptide pools to make amino acids available for protein synthesis. Screening of chromosome substitution isogenic lines for DIP-C activity indicated that, like DIP-A and DIP-B, unlinked activity modifiers exist for Dip-C. The developmental profiles of dipeptidase activities are very similar, except in the pupal stage, during which DIP-C activity is markedly low compared to the other two enzymes. Intercorrelations of dipeptidase activities vary ontogenetically, which is consistent with the need for coordinate expression of these enzymes during certain developmental stages. Tissue-specific expression of dipeptidases in larvae and adults are also similar, although the relative levels of DIP-A activity differ from those of DIP-B and DIP-C in certain organs and body parts. Some of the differences among chromosome substitution lines for dipeptidase activities appear to be systemic, while others are developmental stage-specific and tissue-specific. Second- and third-chromosome variants for DIP-C activity differed in their tissue distribution. This is consistent with the presence of temporal and spatial variants in natural populations for other Drosophila enzymes.

Animals↗
PubMed1989

Orofacial and mandibular reconstruction with the iliac crest free flap: a review of 60 cases and a new method of classification.

Sixty vascularized iliac crest free-tissue transfers were used for oromandibular reconstruction, 46 as osteocutaneous and 14 as osseous flaps. Forty-one patients had preoperative radiotherapy, and 8 had failed previous attempts at reconstruction. Forty-nine of the 60 reconstructions were carried out primarily, most commonly following ablative surgery for radiorecurrent squamous carcinoma. Ages ranged from 19 to 85 years, and follow-up ranged from 2 months to 5 years. Flap survival was 95 percent. Eight-six percent of patients returned to their previous activities. There were 2 perioperative deaths, and 31 patients were alive at follow-up. Horizontal defects from 5 to 16 cm were reconstructed, and in 22 patients, both oral lining and skin coverage were replaced. Radiographic evidence of bone union was noted in 96 percent of synostoses, and clinical union was seen in all but one patient. One patient required bilateral hemimandibular reconstructions for sequential primaries at different operative sittings. Functional and cosmetic results were generally satisfactory and were excellent in bone-only reconstructions. Several surgical principles evolved to minimize bulk and eliminate the need for intermaxillary fixation or external fixation postoperatively. To improve results in large or more lateral through-and-through defects, an accessory pectoralis musculocutaneous flap proved advantageous. Cosmetic and functional results depend largely on three factors: the extent of the surgery, the leanness of the patient, and his or her position on the surgical learning curve.

Adult↗
PubMed1986

Techniques for measuring red cell, platelet, and WBC survival.

Blood cell survival studies yield valuable information concerning production and destruction of cells circulating in the bloodstream. Methodologies for the measurement of red cell survival include nonisotopic methods such as differential agglutination and hemolysis. The isotopic label may be radioactive or, if not, will require availability of a mass spectrograph. These methods fall into two categories, one where red cells of all ages are labeled (51Cr, DFP32, etc.) and those employing a cohort label of newly formed cells (14C glycine, 75Se methionine, etc.). Interpretation of results for methodology employed and mechanism of destruction, random or by senescence, are discussed. A similar approach is presented for platelet and leukocyte survival studies. The inherent difficulties and complications of sequestration, storage, and margination of these cells are emphasized and discussed.

ABO Blood-Group System↗
PubMed1984

Use of sodium chromate Cr51 in diagnosing childhood idiopathic pulmonary hemosiderosis.

The diagnosis of idiopathic pulmonary hemosiderosis (IPH) may be elusive. A 6-year-old boy had microcytic hypochromic anemia and a hemolytic component. Hemosiderin-laden macrophages were not found in the gastric aspirate. He had no pulmonary signs or symptoms. Extensive hematologic and roentgenologic investigations failed to reveal the cause of the anemia. Quantitative serial scintigraphic scanning showed significant (35%) pulmonary sequestration of autologous erythrocytes labeled with sodium chromate Cr51. The half-life of the RBCs was moderately decreased (half-life, 15 days; normal, 25 to 35 days). An open-lung biopsy specimen confirmed the diagnosis of IPH. A diagnosis of IPH should be considered when children have iron deficiency anemia and pulmonary signs or symptoms. Organ sequestration studies may be helpful in equivocal cases.

Anemia, Hypochromic↗
PubMed1981

The use of four-drug combination chemotherapy (D.A.V.E.) in the treatment of advanced Wilms' tumour.

A study was begun in 1971 at St. Bartholomew's Hospital with a combination of 4 drugs, dactinomycin (actinomycin D), adriamycin, vincristine and Endoxan (cyclophosphamide) (D.A.V.E.), together with surgery and radiation, in the treatment of stage III and stage IV Wilms' tumour. Seventy-one percent of the children treated achieved complete response. The median survival from diagnosis was 19 months, and in those children achieving complete response the median disease-free survival has not yet been reached. Toxicity was not a serious problem. The study group is compared with a group of children treated at this hospital before 1971. There is an improved survival in the children treated with D.A.V.E. Children who have relapsed with stage I or stage II disease may also respond. This four-drug combination was well tolerated and effective, and confirms recent experience suggesting that intensive multiple-drug regimens may be curative even in advanced disease.

Adolescent↗
PubMed1978

Combination chemotherapy for acute lymphoblastic leukaemia in adults.

Fifty-one adults with acute lymphoblastic leukaemia were entered into a trial of intense initial chemotherapy and early "prophylaxis" of the central nervous system (CNS). Initial treatment with OPAL (Oncovin (vincristine), prednisolone, adriamycin (doxorubicin), and L-asparaginase (colaspase)) followed by craniospinal or cranial irradiation and intrathecal methotrexate produced remission in 36 patients (71%). Seventeen of these patients relapsed three to 18 months after the start of remission; the remainder had been in remission for 12 to 52 months by the end of the study. The predicted median duration of complete remission was 18.5 months. None of the four patients who initially had clinical evidence of CNS disease, three of whom also had leukaemic cells identical to those found in Burkitt's lymphoma, achieved remission. Those patients who initially had hepatomegaly or splenomegaly had a shorter remission than those without. The predicted median survival was 27 months in those who achieved complete remission, one month in those who did not, and 21 months overall. The addition of colaspase and doxorubicin to vincristine and prednisolone and the use of early CNS treatment clearly improved the remission rate among adults with acute lymphoblastic leukaemia, though the presence and length of remission was affected by the extent of disease at presentation. Burkitt-like leukaemia, which had a poor prognosis, is probably a separate disease and may benefit from a different therapeutic approach.

Adolescent↗
PubMed1976

Radiotherapy and adjuvant combination chemotherapy for childhood rhabdomyosarcoma.

The treatment of children with rhabdomyosarcoma by a combination of surgery, radiotherapy, and chemotherapy has resulted in an improved disease-free survival time. Of 11 children with regional disease eight (72%) remained well, with no evidence of disease, four to 36 months after diagnosis. Chemotherapy for one year with vincristine, actinomycin D, and cyclophosphamide was well tolerated during and after radical radiotherapy and surgery. The natural history of this malignancy has been altered in these patients when compared with that in a historical group of 17 children, only two of whom remain alive. There has been no serious short-term toxicity so far.

Child↗