Biomedical subjects

G E Besner

Publications and source records attributed to G E Besner.

At least 37 records · Page 2Linked to original sources

PubMed1997

Immunohistochemical localization of heparin-binding epidermal growth factor-like growth factor in normal skin and skin cancers.

Heparin-binding epidermal growth factor (EGF)-like growth factor is a 22-kDa glycoprotein that was originally identified as a secreted product of cultured human macrophages. Although the growth factor mRNA has been identified in various cells and tissues, the tissue distribution of the protein itself has rarely been demonstrated. In this study, the EGF-like growth factor was detected immunohistochemically in a variety of human skin samples by indirect immunofluorescence using a polyclonal rabbit antiserum raised against residues 26-41 of mature heparin-binding EGF. The keratinocytes of a variety of epithelium-derived structures demonstrated reproducible, specific staining for the EGF. In normal tissues, this staining was prominent in the basal cells of the epidermis and in the epithelial cells lining epidermal appendages such as hair follicles, sebaceous sweat glands and eccrine sweat glands. In addition, specific staining was detected in skin cancers derived from the basal epithelial cell layer, including basal and squamous cell carcinomas of the skin, with no staining detected in melanoma specimens. Immunoreactive heparin-binding EGF was characteristically associated with the surface of cells. With minor exceptions, the immunoreactive sites are identical to the known EGF receptor distribution in the skin, and suggest that keratinocyte-derived heparin-binding EGF may act in concert with other EGF family members in processes such as skin morphogenesis and wound repair, as well as in the development of skin cancers.

Amino Acid Sequence↗

PubMed1997

Brain heterotopia: choristoma of the back.

Heterotopic brain tissue, except in the head and neck region, is exceedingly rare. Mature neural tissue unexpectedly found in the subcutaneous tissues of the back of a toddler lacked an attachment to the central nervous system (CNS), and appeared to be unorganized glial tissue on pathologic evaluation. Appropriate clinical management of such lesions includes a suspicion of subcutaneous lesions near the CNS and evaluation to eliminate the presence of communication with the CNS, followed by surgical excision.

Back↗

PubMed1996

Characterization of the gene encoding murine heparin-binding epidermal growth factor-like growth factor.

The mouse gene (mHB-EGF) encoding heparin-binding epidermal growth factor-like growth factor was isolated from a mouse 129SVJ genomic library. DNA sequence analysis confirmed that the clone contained six exons (I-VI) and five introns (A-E), and spanned approx. 14 kb of DNA. PCR analysis showed that introns A-E of mHB-EGF are 203 bp, 2.5 kb, 5.5 kb, 825 bp and 272 bp in length, respectively. These results establish that mHB-EGF is similar in organization to human HB-EGF (hHB-EGF). However, DNA sequence analysis of introns A-E of mHB-EGF failed to show significant overall homology with those of hHB-EGF.

Amino Acid Sequence↗

PubMed1996

Production of glycosylated heparin-binding EGF-like growth factor in HeLa cells using vaccinia virus.

Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a 22-kDa, O-glycosylated protein. Because recombinant expression systems permitting a detailed analysis of the functional significance of HB-EGF glycosylation have not been described, a recombinant vaccinia virus designed to express HB-EGF was generated by homologous recombination of an intermediate plasmid vector carrying the HB-EGF cDNA and the genome of vaccinia virus and was used to infect HeLa cells. Production of immunoreactive HB-EGF was confirmed by immunofluorescence and radioimmunoprecipitation analysis. Furthermore, the expressed protein was shown to be a secreted, biologically active protein by radioreceptor and DNA synthesis assays of HeLa cell conditioned medium. The recombinant protein was purified from the conditioned medium using heparin-affinity fast protein liquid chromatography followed by C4 reverse-phase high-performance liquid chromatography (RP-HPLC). SDS-PAGE and Western blotting of the RP-HPLC-purified product showed an immunoreactive HB-EGF protein of approximately 22 kDa that was decreased to a 14-kDa protein by treatment with O-glycanase. Amino acid sequencing revealed an N-terminus that was characteristic of native, glycosylated HB-EGF. Interestingly, a Thr residue that is a putative site of O-linked glycosylation failed to be resolved. This system provides a valuable method for evaluating the role of glycosylation in HB-EGF function(s) as well as addressing other questions concerning HB-EGF structure-function relationships.

Amino Acid Sequence↗

PubMed1996

Small bowel injury in children after blunt abdominal trauma: is diagnostic delay important?

OBJECTIVE: To assess the incidence and consequences of small bowel injury (SBI) in children suffering blunt abdominal trauma managed with the intent to treat nonoperatively. DESIGN: Retrospective chart review. MATERIALS AND METHODS: A total of 168 consecutive hemodynamically stable children admitted to a Level I pediatric trauma center during a 24-month period. RESULTS: Nine of 168 children (5%) sustained SBI: three underwent early (< 4 hours) operation for recognized SBI (identified on computed tomographic scan); and six had delayed (36 +/- 16 hours) operation for missed SBI (not identified on computed tomographic scan). Increased temperature and heart rate, or decreased urine output at 24 hours suggested occult SBI. The hospital course was unaltered by delayed diagnosis. Fifty-seven percent of the children (95) suffered intra-abdominal injury; 10% required laparotomy for SBI (9) or solid organ injury (7); 90% (152) were discharged without laparotomy. CONCLUSIONS: SBI is uncommon in children suffering blunt abdominal trauma. The diagnosis can be made using clinical and radiographic findings. Limited diagnostic delay does not seem to affect outcome. We conclude that clinical diagnosis of SBI is safe, permits the nonoperative treatment of most blunt abdominal injuries, and reduces the risk of unnecessary laparotomy associated with alternate approaches.

Abdominal Injuries↗

PubMed1996

Production of heparin-binding epidermal growth factor-like growth factor (HB-EGF) at sites of thermal injury in pediatric patients.

Fluids that accumulate at wound sites may be an important reservoir of growth factors that promote the normal wound healing response. The presence of heparin-binding growth factors was studied in burn wound fluid (BWF) from 45 pediatric patients who had sustained partial thickness burns. One of the growth factors present was similar to platelet-derived growth factor (PDGF) based on its heparin affinity, inhibition of bioactivity by a PDGF antiserum, and detection in a PDGF-AB enzyme-linked immunosorbent assay. A second growth factor was identified as heparin-binding epidermal growth factor-like growth factor (HB-EGF) based on its heparin affinity, competition with 125I-labeled epidermal growth factor (EGF) for EGF receptor binding, and recognition in biological assays and Western blots by two HB-EGF antisera. Amino acid sequence analysis of one form of this second growth factor verified its identity as an N-terminally truncated form of HB-EGF. Immunohistochemical analysis of partial thickness burns demonstrated the presence of HB-EGF in the advancing epithelial margin, islands of regenerating epithelium within the burn wound, and in the duct and proximal tubules of eccrine sweat glands. HB-EGF in the surface epithelium of burn wounds was uniformally distributed, whereas it was restricted to the basal epithelium in nonburned skin. These data support a role for PDGF and HB-EGF in burn wound healing and suggest that the response to injury includes deposition of HB-EGF and PDGF into blister fluid and a redistribution of HB-EGF in the surface epithelium near the wound site.

Adolescent↗

PubMed1996

Identification of a duplicated undescended testicle (polyorchia): an unexpected benefit of laparoscopic localization.

Polyorchidism is an uncommon anomaly resulting from transverse division of the embryonic genital ridge. Up to 50 percent of cases are associated with cryptorchidism. The present case describes a 6-year-old boy who was referred for evaluation of an undescended right testicle. Examination revealed compensatory hypertrophy of the left testis (2 cm length; 2 cc volume; volume twice normal for age). These measurements were consistent with the presence of monorchidism rather than cryptorchidism. Laparoscopy was performed to confirm the absence of the nonpalpable testicle and to localize any testicular remnants. Laparoscopic findings included a hypoplastic testicle at the mid lumbar it level (abdominal testis) and a second hypoplastic testicle just distal to the internal inguinal ring (inguinal testis). Both measured no more than 1 cm in greatest diameter and were excised laparoscopically. Histologic examination revealed two immature tests, with the abdominal testis demonstrating atrophy. It is well recognized that laparoscopy the high undescended testicle, or identification of testicular remnants. In addition, nonpalpable testicle assists in localization of the undescended testicle or identification of the testicular remnants. In addition,laparoscopic high ligation and division of the gonadal vessels can be performed in cases of the high undescended testicle. Moreover, as demonstrated here, laparoscopy may also allow identification of polyorchia, especially in cases where the proximal testicle is intraabdominal. Inguinal exploration alone may result in failure to recognize a higher duplicated gonad. Failure to recognize and excise the duplicated, potentially dysplastic testicle may place the child at risk for subsequent malignant degeneration.

Child↗

PubMed1995

Intraoperative detection and resection of occult neuroblastoma: a technique exploiting somatostatin receptor expression.

Tumor cell expression of specific high-affinity somatostatin receptors has been associated with a favorable prognosis in children with neuroblastoma. The purpose of this study was (1) to document intraoperatively the in vivo binding of the somatostatin analogue 125I-tyr3-octreotide to high-affinity somatostatin receptors expressed on human neuroblastoma, using a hand-held gamma detector; (2) to determine whether gamma-probe detection of radioligand binding to tumor receptors could identify occult malignancy; and (3) to determine the safety and biodistribution of 125I-tyr3-octreotide in children. Six children with stage III or IV neuroblastoma received an intravenous injection of 125I-tyr3-octreotide and underwent operative exploration using gamma-probe detection of radioligand binding to tumor somatostatin receptors. Tissue that demonstrated in vivo binding of 125I-tyr3-octreotide, or that was suspicious for tumor, was extirpated and analyzed by histopathology, immunohistochemistry, and microautoradiography. The biodistribution of 125I-tyr3-octreotide was recorded intraoperatively over time. Tumor tissue from each child also was assayed in vitro for somatostatin receptor expression by competitive binding studies using 125I-tyr3-octreotide. In vivo binding of 125I-tyr3-octreotide to malignant tissue was documented in the five children with a known tumor burden. Seventeen sites of radioreceptor binding were amenable to resection. Histopathological analysis confirmed neuroblastoma in 15 of these specimens. Four of the 15 proven tumor foci were occult malignancies. Every site of histologically proven neuroblastoma demonstrated in vivo binding of 125I-tyr3-octreotide. Five of seven sites histologically negative for neuroblastoma also were negative for in vivo radioreceptor binding. Microautoradiography confirmed in vivo binding of 125I-tyr3-octreotide to tumor cells. Uptake of 125I-tyr3-octreotide in abdominal organs occurred within 15 minutes of injection, was highest in the liver and gallbladder, and decreased over 24 hours. The conclusions were as follows. (1) 125I-tyr3-octreotide binds, in vivo, to somatostatin receptors on neuroblastoma, with 100% sensitivity and 71% specificity. (2) Occult neuroblastoma is found through gamma-probe detection of radioligand binding to receptors. (2) The biodistribution of 125I-tyr3-octreotide reflects the hepatobiliary clearance of this radionuclide. (4) Radioreceptor-guided surgery may safely provide more complete operative staging and cytoreduction of neuroblastoma.

Biomarkers, Tumor↗

PubMed1995

Unique protein expression by the TBJ clonal derivative of C1300 murine neuroblastoma.

C1300 is a murine neuroblastoma that arose spontaneously in an A/JAX mouse, and from which a clone termed TBJ was subsequently derived. C1300 is a slowly growing and poorly metastasizing tumor, whereas TBJ shows early systemic metastasis as well as aggressive local growth. Compared with TBJ cells, C1300 cells are highly immunogenic and are sensitive to natural killer cells and cytotoxic lymphocytes. In vitro, TBJ cells were found to be more rounded and less adherent than C1300 cells. Because the underlying basis for the differences between C1300 and TBJ cells has not been fully elucidated, the authors used high-resolution two-dimensional gel electrophoresis (2-DE) to study comparative aspects of total protein expression by each cell line. Of the approximately 400 individual cellular proteins that could be resolved using this technique, two were found to be reproducibly and uniquely expressed by TBJ cells and not by C1300 cells. Both proteins were anionic (pl 5.0 to 5.2) as assessed by iso-electric focusing and had molecular weights of 76,000 and 82,000 as assessed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Silver staining of SDS-polyacrylamide gels showed that the levels of 82,000-M(r) protein (p82) were higher than those of the 76,000-M(r) protein (p76). A purification protocol allowing for the isolation of p82 from TBJ cell extracts was developed, which comprised preparative two-dimensional gel electrophoresis followed by reverse-phase high-performance liquid chromatography. Full molecular identification of p82 and p76 eventually may provide new leads in the study of the metastatic or antigenic properties of neuroblastoma.

Animals↗

PubMed1995

Penetrating neck trauma in children: a reappraisal.

The management of penetrating neck injuries in adults is controversial, with a trend toward selective neck exploration. These injuries are uncommon in children, and only limited information exists regarding their management. To assess the management of these injuries in the authors' geographic region, they reviewed the records of children with injuries penetrating the platysma muscle who were treated between 1980 and 1994. Forty-six children (aged 2 to 16 years) suffered a total of 55 penetrating neck injuries. The injuries were classified according to type and location. Fifty-two percent were caused by missiles, 30% by stab wounds, and 18% by dog bites. Fifty-eight percent of injuries were in zone II, 31% in zone I, and only 11% in zone III. The diagnostic workup, including arteriography, esophagography, or endoscopy, was performed preoperatively in 10 patients. Overall, 21 patients had exploration, and the rate of negative explorations was 48%. All cases explored for bleeding or a positive diagnostic workup result were found to have significant injury. On the other hand, all neck explorations performed solely because of injury to zone II were negative. The overall morbidity and mortality rates were 31% and 7%, respectively. A more selective approach, similar to that used for adult patients, emphasizing preoperative diagnostic evaluation, is recommended to decrease the rate of negative neck explorations among children.

Adolescent↗

PubMed1995

Purification of heparin-binding epidermal growth factor-like growth factor from pig uterine luminal flushings, and its production by endometrial tissues.

Pig uterine luminal flushings contain at least four heparin-binding growth factors (HBGF) that stimulate fibroblast [3H]thymidine incorporation. One of these factors, which appeared to be a relatively minor HBGF, was eluted from heparin affinity columns by 1.0 M NaCl and was found to compete with 125I-epidermal growth factor (EGF) for binding to an endometrial carcinoma cell line. This EGF receptor (EGF-R)-binding property was abolished by an antiserum to heparin-binding EGF-like growth factor (HB-EGF) that specifically blocks binding of HB-EGF to the EGF-R. Reverse-phase HPLC resulted in the purification of two EGF-R-binding activities correlated with 13,500 and 17,000 M(r) proteins that reacted with an antiserum raised against residues 9-26 of human HB-EGF. Uterine extracts also contained an EGF-R-binding factor that was eluted from heparin by 1.0 M NaCl and was antagonized by HB-EGF antiserum. Endometrial mRNA subjected to reverse transcriptase-polymerase chain reaction (RT-PCR) and nested PCR through the use of HB-EGF-specific primers yielded fragments of the predicted size. Cloning of the nested PCR product revealed a 380-bp porcine HB-EGF cDNA sequence that was 78-85% homologous to primate or rodent HB-EGF. HB-EGF was immunohistochemically localized primarily to the luminal epithelium in both pregnant and nonpregnant animals.

Animals↗

PubMed1994

Absent intestinal musculature: anatomic evidence of an embryonic origin of the lesion.

Absent intestinal musculature is a rare entity of uncertain etiology. The diagnosis is confirmed histologically by segmental absence of the intestinal muscularis. The remaining layers of the bowel wall are completely intact, and notably absent are significant inflammation and hemorrhage. The authors report two cases of segmental absence of intestinal musculature presenting as perforations. There was gross or microscopic evidence of diverticula formation at sites of perforation and absent muscle. Based on the anatomic evidence in these specimens and a review of the surgical literature, we propose that the etiology is based on embryologic diverticuli.

Child, Preschool↗

PubMed1992

Structure of heparin-binding EGF-like growth factor. Multiple forms, primary structure, and glycosylation of the mature protein.

Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a newly described member of the epidermal growth factor (EGF) family that is mitogenic for BALB/c 3T3 cells, inhibits the binding of 125I-EGF to its receptor, and triggers autophosphorylation of the EGF receptor. HB-EGF was purified from the conditioned medium of U-937 cells using cation exchange, copper affinity, heparin affinity, and two rounds of C4 reversed phase liquid chromatography. The elution profile of the first round of C4 column chromatography contained four growth factor activity peaks with similar specific biological activities. N-terminal and tryptic fragment microsequencing demonstrated that these peaks contained different structural forms of the HB-EGF protein. Some of the differences in the various forms of HB-EGF were found to be due to N-terminal heterogeneity. Microsequencing of tryptic fragments indicated that the mature HB-EGF polypeptide can contain at least 86 of the 208 amino acids predicted by nucleotide sequence to be the HB-EGF precursor molecule. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis indicated that the various forms of HB-EGF have apparent molecular masses of 19-23 kDa. Further analysis of the most predominant form of HB-EGF found in U-937 cell conditioned medium indicated that it has a pI of 7.2-7.8 and is O-glycosylated.

3T3 Cells↗

PubMed1992

Pathophysiology of congenital diaphragmatic hernia. III: Exogenous surfactant therapy for the high-risk neonate with CDH.

Exogenous surfactant therapy (EST) in surfactant-deficient premature infants has been shown to improve lung compliance, decrease morbidity, and improve survival. Reports have demonstrated that newborns with congenital diaphragmatic hernia (CDH) have lung compliance, pressure-volume curves, and hyaline membrane formation resembling those changes seen in surfactant deficient premature newborns. We hypothesize that EST may also benefit infants with CDH. All high risk cases of prenatally diagnosed CDH at Children's Hospital of Buffalo from November 1988 to February 1991 were prospectively evaluated for EST. In those families who chose to participate, the surfactant preparation, Infasurf (100 mg/kg), was instilled into the newborn's lungs prior to the first breath. The remainder of the perinatal, neonatal, and surgical care was performed in a routine manner. Three high-risk prenatally diagnosed newborns with left CDH were treated with EST. All showed signs of decreased pulmonary compliance, but could still be adequately oxygenated and ventilated. Surgical correction was performed after stabilization and all required patch closures. Two of the three infants suffered no life-threatening episodes of pulmonary hypertension and all survived. These infants had many known indicators for poor outcome in CDH with an expected survival of less than 20%. We believe that EST in these neonates with CDH contributed to their survival with minimum morbidity. These results suggest that surfactant replacement for the high-risk neonate with CDH warrants further consideration and a randomized clinical trial is being planned.

Adult↗

PubMed1992

Recombinant human granulocyte colony-stimulating factor promotes wound healing in a patient with congenital neutropenia.

We report a patient with congenital neutropenia or Kostmann's Syndrome who suffered many complications after presenting with Clostridium septicum enterocolitis, including absence of wound healing. Because of several reports of the use of granulocyte colony-stimulating factor (G-CSF) in patients with various complications of neutropenia, we treated this patient with recombinant human (rh) G-CSF. We found that once rhG-CSF restored neutrophil counts to normal, progressive wound healing followed. Thus, rhG-CSF therapy may be useful in treating neutropenic patients with wound complications.

Adolescent↗

PubMed1992

Interaction of heparin-binding EGF-like growth factor (HB-EGF) with the epidermal growth factor receptor: modulation by heparin, heparinase, or synthetic heparin-binding HB-EGF fragments.

The binding of heparin-binding EGF-like growth factor (HB-EGF) to the epidermal growth factor (EGF) receptor of human endometrial carcinoma cells was compared to that of EGF using an 125I-EGF radioreceptor assay. The inhibitory effect of HB-EGF on 125I-EGF binding was reversed either in the presence of heparin (but not by chondroitin sulfate) or by pre-treating the cells with heparinase. These treatments did not affect the binding of EGF to its receptor. To map potential regions in the HB-EGF molecule that mediate its heparin-dependent interaction with the EGF receptor, HB-EGF peptides were synthesized that were non-homologous to EGF. Accordingly residues 20-25 and 36-41, but not residues 8-19, of HB-EGF were found to be (i) heparin-binding and (ii) modulators of HB-EGF (but not of EGF) binding to the EGF receptor.

Amino Acid Sequence↗

PubMed1991

Macrophages secrete a heparin-binding inhibitor of endothelial cell growth.

Macrophages may play an important role in the regulation of angiogenesis by secreting modulators of endothelial cells (EC) proliferation. To investigate this, human mononuclear cells were plated in culture, and the conditioned media of these cells were analyzed by heparin-Sepharose affinity chromatography. The fractions were tested for modulation of EC growth, as determined by endothelial cell number in proliferation assays. A single peak of EC growth-inhibitory activity was found to elute from heparin-Sepharose with 1.0 M NaCl. Secretion of this EC inhibitor persisted for many weeks in cell culture, at which point the cultures consisted of adherent macrophages only. This activity was therefore designated as macrophage-derived endothelial cell inhibitor (MD-ECI). Analysis using specific neutralizing antisera as well as comparative heparin affinity analysis showed that MD-ECI was distinct from the known EC inhibitors TGF-beta and TNF-alpha. MD-ECI inhibits basal EC growth as well as FGF-stimulated EC growth. Its effect on EC is dose-dependent, nontoxic, and reversible.

Binding, Competitive↗

PubMedDate not supplied

Acceleration of partial-thickness burn wound healing with topical application of heparin-binding EGF-like growth factor (HB-EGF).

Heparin-binding EGF-like growth factor has been identified in human burn-wound fluid and in the epithelial cells of excised human partial-thickness burns. In the present study, the effect of heparin-binding EGF-like growth factor on burn-wound healing was evaluated by incorporating purified, recombinant heparin-binding EGF-like growth factor into slow-release cholesterol-lecithin pellets that were applied topically to partial-thickness burns in mice. Both experimental (heparin-binding EGF-like growth factor-treated) and control (untreated) mice were sacrificed on days 3, 5, and 10 after burn. Total burn-wound area, histology, keratinocyte proliferation, and in situ hybridization analysis for transforming growth factor-alpha were determined for each wound. The mean wound area of the experimental group on day 5 after burn was 1.07 cm2, compared with 2.20 cm2 for controls (p=0.04). Cellular proliferation (as measured by immunohistochemical detection of 5-Bromo-2-deoxyuridine) on day 5 after burn in marginal keratinocytes and follicular epithelial cells was greater in the experimental group than in the control group. In situ hybridization showed up-regulation of transforming growth factor-alpha mRNA levels in experimental animals by day 5 after burn. Topical application of heparin-binding EGF-like growth factor significantly accelerates the reepithelialization of murine partial-thickness burns, increases keratinocyte proliferative activity, and enhances production of endogenous transforming growth factor-alpha mRNA.

Administration, Topical↗