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Biomedical subjects

J E Allen

Publications and source records attributed to J E Allen.

At least 19 recordsLinked to original sources
PubMed1992

Comparative analysis of successful and unsuccessful candidates for the pediatric surgical matching program.

Only one third of the applicants for training in pediatric surgery obtain a position through the pediatric surgery matching program. In order to identify factors that contribute to a successful outcome, we conducted a retrospective survey of all participants in the matching process for positions during the years 1983 to 1991. This survey was designed to identify characteristics associated with success in the match through comparison of successful and unsuccessful applicants. Significant factors associated with a successful match included: a greater incidence of residency-supported research (P = .012) with a greater number of publications (P = .003) and national presentations (P = .014), specifically at the annual meetings of the American Pediatric Surgical Association (P = .05) and the American Academy of Pediatrics (P = .05). In addition, successful candidates had more contact with (P = .004) and letters of recommendation from (P = .015) well-known pediatric surgeons involved in the general surgical residency program. This information should be invaluable to those counseling medical students and residents interested in a career in pediatric surgery.

Adult↗
PubMed1992

Pathophysiology of congenital diaphragmatic hernia II: the fetal lamb CDH model is surfactant deficient.

The high mortality for congenital diaphragmatic hernia (CDH) has been attributed to a combination of pulmonary hypoplasia and pulmonary hypertension. We hypothesize that a surfactant deficiency may in part be contributing to the pathophysiology of CDH. This study documents the functional, quantitative, and qualitative aspects of the surfactant status of the alveolar air-liquid interface and the type II pneumocyte in the fetal lamb CDH model. Ten lamb fetuses (gestational age, 80 days) had a CDH created via a left thoracotomy and then were allowed to continue in utero development until term. Three litter mates and three nonoperated time-dated fetuses served as controls. At term, pressure-volume curves were performed to measure pulmonary compliance and total lung capacity. Alveolar lavage was then performed to measure the quantitative and the qualitative aspects of pulmonary surfactant. Finally, isolation of type II pneumocytes allowed quantification of phospholipid synthesis. When compared with controls (N = 6), the CDH lambs (N = 5) had significantly smaller lungs (P = .009), decreased total lung capacity (P less than .001) and compliance (P less than .001), reduced total lavaged phospholipids (P = .006), and decreased percent phosphatidylcholine (P = .02). CDH lambs also had increased total lavaged proteins (P = .05) and higher minimum dynamic surface tension (P less than .001). A surfactant deficiency may be contributing to the pathophysiology of CDH. Surfactant replacement therapy in premature infants has been shown to improve lung compliance, decrease morbidity, and improve survival. Exogenous surfactant may also benefit infants with CDH.

Animals↗
PubMed1992

Immune specificity of murine T-cell lines to the major outer membrane protein of Chlamydia trachomatis.

The antigenically variant Chlamydia trachomatis major outer membrane protein (MOMP) is a target of antibody-mediated neutralization in vitro, and it is an important protein for designing a subunit vaccine. Knowledge of MOMP T-cell determinants will be essential to elicit rapid and strong immune responses following an encounter with infectious organisms. C. trachomatis-specific T-cell lines were derived from MOMP-immunized BALB/c mice and selected with intact organisms. We used these short-term T-cell lines to identify determinants of MOMP that could be recognized by T cells following processing of the intact organism. T-cell line proliferation in response to overlapping MOMP peptides showed that only a peptide encompassing the third variable segment (VS3) elicited a strong proliferative response. We further mapped determinants within the VS3 peptide and found that a sequence-conserved portion of the VS3 peptide elicited T-cell proliferation of T-cell lines from BALB/c mice. Thus, unlike the response to several MOMP peptides with unselected T cells, development of short-term T-cell lines with intact organisms restricted the repertoire of antigens capable of being recognized by MOMP-specific T cells.

Amino Acid Sequence↗
PubMed1992

Teicoplanin in the treatment of bone and joint infections. Teicoplanin Bone and Joint Cooperative Study Group, USA.

Teicoplanin is a new glycopeptide antibiotic with activity against Gram-positive bacteria, including methicillin-resistant organisms. Teicoplanin is administered once daily, either intravenously or intramuscularly. Teicoplanin was given once daily, intravenously or intramuscularly, in the treatment of hospitalized or ambulatory patients with Gram-positive bone or joint infections. A total of 90/98 patients were evaluated for efficacy; 41 had acute osteomyelitis, 41 had chronic osteomyelitis, and 8 had septic arthritis. At the end of therapy, 37 acute osteomyelitis patients were cured/improved with a 90% cure rate at 6-month follow-up; 2 relapsed and 1 failed. At the end of therapy 30 chronic osteomyelitis patients were cured/improved with an 88% cure rate at 6-month follow-up; 2 relapsed and 1 failed. 100% of the septic arthritis patients were cured at the end of therapy and at 1-month follow-up. The most common bacterial isolates cultured from bone were S. aureus (39 isolates), S. epidermidis (11 isolates), other coagulase-negative staphylococci (20 isolates), enterococci (6 isolates), and other streptococcal species (20 isolates). The most common bacterial isolates cultured from joint fluid were S. aureus (6 isolates) and S. epidermidis (2 isolates). All patients tolerated the intramuscular or intravenous routes of administration well. Adverse reactions were mild and most cases did not require discontinuation of therapy. The majority of therapy was administered on an outpatient basis. Teicoplanin was safe, effective, convenient and relatively well tolerated in patients with acute or chronic osteomyelitis or septic arthritis.

Acute Disease↗
PubMed1991

A single peptide from the major outer membrane protein of Chlamydia trachomatis elicits T cell help for the production of antibodies to protective determinants.

The protective immune response to infection with Chlamydia trachomatis is associated with antibody reactivity to serovar-specific determinants on the major outer membrane protein (MOMP). Because this immunity is T cell dependent, it is essential to define those Th cell determinants that promote natural boosting of the protective antibody response. The gene for MOMP of serovar B was separated into nine overlapping fragments that represent the five C and four V regions. These fragments were expressed as fusion peptides with GST and used to identify the regions of the MOMP that contain T cell determinants recognized in BALB/c mice. We identified peptides that elicit a T cell response to Chlamydia by immunizing mice with the fusion peptides and testing the proliferative response of T cells in vitro to intact organism. For analysis of determinants seen after infection, animals were inoculated with live organism and the T cell proliferative response to each fusion peptide was measured in vitro. In contrast to proliferative analysis in which several regions of the MOMP elicited T cell responses, functional analysis demonstrated that a single fusion peptide, containing V segment three, elicited T cell help in vivo for the production of high titered antisera, specific for protective determinants on the MOMP.

Animals↗
PubMed1991

Constitutional extra chromosomal element in a family with Wilms' tumor.

We report the presence of an extra chromosomal element in a family with Wilms' tumor (WT). This family has three children, two of whom were affected. One son, the proband, had bilateral and one daughter had unilateral WT. The first child, the father, and the mother did not have WT. The son with bilateral WT had a ring chromosome (R) both in the lymphocytes as well as in the kidney tissue. The size of the ring varied considerably from cell to cell. The daughter with unilateral WT had an abnormal clone containing a small chromosomal ring (r) in phytohemagglutinin (PHA)-stimulated and Epstein-Barr virus (EBV)-transformed lymphocytes. The mother had a karyotype similar to that of the daughter with WT. We hypothesize that the proband's ring chromosome could be the amplified form of the r inherited from the mother. Chromosome 11 was cytogenetically normal in all the cells examined of the affected children and the unaffected mother. In situ hybridization with a centromere-specific DNA cocktail indicated dispersed centromeric DNA both in r and R.

Adult↗
PubMed1991

Familial Hirschsprung's disease: report of autosomal dominant and probable recessive X-linked kindreds.

Multifactorial sex-modified inheritance has been proposed as the model of transmission in familial Hirschsprung's disease (HD). A review of two separate kindreds suggests that aganglionosis may be inherited as an X-linked recessive or an autosomal dominant trait. Chromosomal anomalies and other syndromes, including G6PD deficiency, may occur with familial HD. Recurrence risk counseling for family members depends on accurate pedigree analysis and a comprehensive understanding of the genetic factors involved.

Female↗
PubMed1991

Enhanced resection and improved survival in murine neuroblastoma (C1300-NB) after preoperative immunotherapy.

Advanced neuroblastoma treated with standard chemotherapy has a poor prognosis. Combination immunotherapy for murine neuroblastoma with retinyl palmitate, low-dose cyclophosphamide, and interleukin-2 resulted in increased survival, impaired tumor growth, easier surgical resection, and increased class I expression or tumor cells. Preoperative immunotherapy may be useful in treatment of advanced human neuroblastoma.

Animals↗
PubMed1991

Early cortical tactile-evoked potentials, laterality and schizophrenia.

No significant difference in the lateralisation of tactile-evoked potentials was found when a tactile stimulus was applied to the index finger of 14 schizophrenic patients and 14 age- and sex-matched controls. The early tactile responses, recorded from contralateral and ipsilateral parietal scalp electrodes, were compared. Our results differ from previously reported results.

Adult↗
PubMed1990

National standards for the licensure of nursing home administrators: what should be sought?

In recent years a national debate has focused on the licensure of nursing home administrators. Congress mandated licensure goals in 1970, but recently has considered eliminating the requirement that states license nursing home administrators. Data showing trends during 1977-1987 in education, internship, professional examinations, and reciprocity requirements are evaluated in this paper, and three recommendations for national standards are made.

Health Facility Administrators↗
PubMed1990

Cysteine-rich outer membrane proteins of Chlamydia trachomatis display compensatory sequence changes between biovariants.

Two cysteine-rich proteins of Chlamydia trachomatis are essential structural components of the unique outer membrane of the infectious elementary body. These 58,000 (outer membrane protein 2; OMP2) and 15,000 (OMP3) proteins also differ structurally and chemically between biovariants that differ in invasive capability. We have identified the gene for OMP3 and sequenced both trachoma and lymphogranuloma venereum (LGV) omp3 genes. We have previously sequenced omp2 from the LGV biovar and now describe the omp2 sequence for a trachoma biovariant. Amino acid sequence differences between biovariants were few but, significantly, these changes have altered the charge of both OMP2 and OMP3 such that the net charge of each protein differs between biovariants. These compensatory charge alterations have implications for the outer membrane organization of these proteins. In addition, examination of the OMP3 sequence suggests that OMP3 may be a lipoprotein.

Amino Acid Sequence↗
PubMed1989

The role of pediatric surgery in the medical school curriculum.

In most medical schools, exposure to pediatric surgery is presented as a subspecialty elective. We have offered it as an integral part of the surgical clerkship for 10 years in the belief that it provides an excellent educational environment. To confirm this concept, the quizzes (Q), final examinations (FE), and grades of students assigned to the pediatric surgical service were prospectively studied. All students (N = 139) in the surgical clerkship entered the study. Thirty-two students were randomly selected and assigned to the surgical service of a major pediatric hospital (P-Surg) for 50% of their clerkship. The other students (N = 107) were assigned to a variety of adult surgical services (G-Surg) and served as the control group. All students attended the same seminars, used the same educational materials, were examined with the same test items, and were evaluated by the same oral examiners. Test items were electronically scored and the database was analyzed on an IBM computer. The statistical analysis was performed using a Student's t test and chi 2 analysis. There was no significant difference in the demonstrated cognitive performance and grades awarded to the two groups of students. We conclude that a pediatric surgical service provides an atmosphere that is educationally comparable to the adult general surgical service.

Curriculum↗
PubMed1989

Immune consequences of nonoperative treatment of splenic trauma in the rat model.

To investigate the immunologic consequences of non-operative management of splenic injury, three parameters were studied: survival following pneumococcal sepsis, clearance of blood-borne bacteria, following Hemophilus influenzae challenge, and antibody response to type III pneumococcal capsular polysaccharide. Two hundred twenty-five Sprague-Dawley rats were divided into three groups and subjected either to a splenectomy, a sham operation, or standard blunt trauma. A significant increase in mortality was noted in the splenectomized group as compared with both the traumatized and control groups when challenged with Streptococcus pneumoniae. In both the control and trauma groups, H influenzae cleared significantly within 18 hours. Blood-borne bacteria persisted at the same level for 72 hours in the splenectomized animals. Four and 11 days later, the antibody level in both traumatized and control groups was higher than in the splenectomized subjects (P less than .001). There was no difference in the serum antibody level between the control and trauma groups at four days. However, at 11 days the trauma group showed a significant decrease in the antibody level (P less than .05). It can be concluded that following spontaneously-healing splenic trauma in the rat model, survival, bacterial clearance, and antibody response were all superior to that observed in the splenectomized subjects. In addition, the healed splenic disruption did not impair clearance of blood-borne encapsulated bacteria.

Animals↗
PubMed1989

Changing susceptibility of Pseudomonas aeruginosa isolates from cystic fibrosis patients with the clinical use of newer antibiotics.

To detect a change in antibiotic susceptibility patterns in Pseudomonas aeruginosa isolates upon the introduction and clinical use of ciprofloxacin, aztreonam, and ceftazidime, MICs for clinical isolates collected before introduction of the antibiotics, during early clinical use, and later were determined for these and seven other antipseudomonal antibiotics. Concomitant resistance to two or more antibiotics was also studied. Over the three study periods, rates of susceptibility to 9 of the 10 antibiotics decreased. The largest decrease occurred with ceftazidime. Analysis of subsets of isolates from patients treated with ciprofloxacin or aztreonam also showed declining susceptibility to the latter but a stabilization of susceptibility to the former after an initial decline. Concomitant resistance within and among antibiotic classes was common.

Anti-Bacterial Agents↗
PubMed1989

Identification by sequence analysis of two-site posttranslational processing of the cysteine-rich outer membrane protein 2 of Chlamydia trachomatis serovar L2.

The 60,000-molecular-weight cysteine-rich outer membrane protein (OMP2) from Chlamydia trachomatis participates in the disulfide-mediated outer-membrane organization unique to this organism. In addition, this protein is a primary focus of the host immune response. We cloned and sequenced the gene for OMP2 from C. trachomatis serovar L2. A lambda gt11 recombinant that expressed an antigenic portion of this protein was selected by antibody screening and provided a probe for the selection in lambda 1059 of a clone containing the entire gene. DNA sequencing of this clone identified one open reading frame of 1,641 base pairs, starting with a methionine codon and coding for a polypeptide with a molecular weight of 58,792. Amino-terminal protein sequencing and analysis of the translated DNA sequence demonstrated that processing at alternate signal peptide cleavage sites accounts for the molecular-weight polymorphism of this protein. The mature proteins had a net positive charge and contained 24 cysteine residues.

Amino Acid Sequence↗
PubMed1988

Intramural hematoma of the duodenum.

Intramural duodenal hematoma in children is one of the least common injuries encountered. Because of the rarity of this problem, there has been little conformity of opinion as to the relative merits of operative vs nonoperative management. We reviewed 182 cases of this condition, of which 168 were taken from the English literature and 14 from our hospital. Pancreatitis was the most common associated intra-abdominal lesion (21%), while central nervous system, skeletal, and thoracic injuries (5%) accounted for the major extra-abdominal injuries. Hemophilia, von Willebrand's disease, and idiopathic thrombocytopenic purpura occurred in 7 cases and played a major role in the prognosis. Of these cases, 121 patients were treated surgically and 61 conservatively. The average hospitalization was 14 days for the surgical group and 11 days for the conservative group. There were 18 complications in the surgical group. It appears that most patients with intramural duodenal hematoma would respond well to conservative management. Surgery should be reserved for those cases that remain obstructed over seven to ten days or have evidence of perforation.

Adolescent↗
PubMed1988

Culturing and robotic harvesting of bone marrow, lymph nodes, peripheral blood, fibroblasts, and solid tumors with in situ techniques.

We have modified our in situ method for culturing amniocytes and have successfully used this new procedure to culture cells from bone marrow, lymph nodes, peripheral blood, fibroblasts, and solid tumors. We have been so satisfied with this method that we have used it in our routine practice for the past 2.5 years. A convenient feature of the in situ method is that the cultures can be processed with a commercially available robotic harvesting system (modified Tecan Robotic Sample Processor Model 505). This system also works well for in situ cultures of amniotic fluids. Robotic harvesting of in situ cultures provides a consistent and accurate procedure that saves about 10-15 minutes of technologist time per case.

Blood Cells↗