[Laparoscopic cholecystectomy in patients with earlier laparotomy]

Previous abdominal surgery has been reported as a relative contraindication to laparoscopic cholecystectomy. A retrospective analysis of 356 laparoscopic cholecystectomies was undertaken to determine whether previous abdominal surgery led to increased morbidity. The results of 116 patients who had had previous abdominal surgery were compared with those of 240 patients without previous abdominal surgery. The rate of conversion to open operation was not increased. The operating time was a little increased. There were no increases in either minor or major postoperative complications in patients with previous abdominal surgery, and the in-hospital stay time was the same. The median recovery time was respectively ten versus eight days in patients with and without previous surgery. We conclude that previous abdominal surgery is not a contraindication to laparoscopic cholecystectomy.

A mathematical model for fibro-proliferative wound healing disorders

The normal process of dermal wound healing fails in some cases, due to fibro-proliferative disorders such as keloid and hypertrophic scars. These types of abnormal healing may be regarded as pathologically excessive responses to wounding in terms of fibroblastic cell profiles and their inflammatory growth-factor mediators. Biologically, these conditions are poorly understood and current medical treatments are thus unreliable. In this paper, the authors apply an existing deterministic mathematical model for fibroplasia and wound contraction in adult mammalian dermis (Olsen et al., J. theor. Biol. 177, 113-128, 1995) to investigate key clinical problems concerning these healing disorders. A caricature model is proposed which retains the fundamental cellular and chemical components of the full model, in order to analyse the spatiotemporal dynamics of the initiation, progression, cessation and regression of fibro-contractive diseases in relation to normal healing. This model accounts for fibroblastic cell migration, proliferation and death and growth-factor diffusion, production by cells and tissue removal/decay. Explicit results are obtained in terms of the model processes and parameters. The rate of cellular production of the chemical is shown to be critical to the development of a stable pathological state. Further, cessation and/or regression of the disease depend on appropriate spatiotemporally varying forms for this production rate, which can be understood in terms of the bistability of the normal dermal and pathological steady states-a central property of the model, which is evident from stability and bifurcation analyses. The work predicts novel, biologically realistic and testable pathogenic and control mechanisms, the understanding of which will lead toward more effective strategies for clinical therapy of fibro-proliferative disorders.

Field tolerance to fungal pathogens of Brassica napus constitutively expressing a chimeric chitinase gene

Constitutive overexpression of a protein involved in plant defense mechanisms to disease is one of the strategies proposed to increase plant tolerance to fungal pathogens. A hybrid endochitinase gene under a constitutive promoter was introduced by Agrobacterium-mediated transformation into a winter-type oilseed rape (Brassica napus var. oleifera) inbred line. Progeny from transformed plants was challenged using three different fungal pathogens (Cylindrosporium concentricum, Phoma lingam, Sclerotinia sclerotiorum) in field trials at two different geographical locations. These plants exhibited an increased tolerance to disease as compared with the nontransgenic parental plants.

Monoclonal antibodies against human immunodeficiency virus type 1 integrase: epitope mapping and differential effects on integrase activities in vitro

Human immunodeficiency virus type 1 (HIV-1) integrase (IN) catalyzes the integration of viral DNA into the host chromosome, an essential step in retroviral replication. As a tool to study the structure and function of this enzyme, monoclonal antibodies (MAbs) against HIV-1 IN were produced. Epitope mapping demonstrated that the 17 MAbs obtained could be divided into seven different groups, and the selection of MAbs representing these groups were tested for their effect on in vitro activities of IN. Four groups of MAbs recognized epitopes within the region of amino acids (aa) 1 to 16, 17 to 38, or 42 to 55 in and around the conserved HHCC motif near the N terminus of IN. MAbs binding to these epitopes inhibited end processing and DNA joining and either stimulated or had little effect on disintegration and reintegration activities of IN. Two MAbs binding to epitopes within the region of aa 56 to 102 in the central core or aa 186 to 250 in the C-terminal half of the protein showed only minor effects on the in vitro activities of IN. Three Mabs which recognized on epitope within the region of aa262 to 271 of HIV-1 IN cross-reacted with HIV-2 IN. MAbs binding to this epitope clearly inhibited end processing and DNA joining and stimulated or had little effect on disintegration. In contrast to the N-terminal-specific MAbs, these C-terminal-specific MAbs abolished reintegration activity of IN.

Localization of neurotrophins and their high-affinity receptors during human enteric nervous system development

BACKGROUND & AIMS

Interactions of neurotrophins with the appropriate trk receptors result in growth and maturational alterations in nervous system cells during development. The aim of this study was to examine whether similar interactions could be involved in human enteric nervous system (ENS) survival or differentiation as well.

METHODS

Immunocytochemical detection of TrkA, TrkB, and TrkC, as well as the ligands neurotrophin 3 (NT-3) and brain-derived neurotrophic factor (BDNF), was accomplished on normal human fetal and postnatal intestine.

RESULTS

Neither neurotrophins nor their receptors were identified in immature postmigrational ENS progenitors at 7 weeks' fetal developmental age; however, TrkC and TrkA were specifically localized to developing ENS cells after 19 developmental weeks. From infancy through adulthood, TrkA and TrkB immunoreactivities were localized to both enteric ganglion cells and glia, whereas TrkC was localized exclusively to enteric ganglion cells. In postnatal intestine, BDNF immunoreactivity was primarily localized to enteric ganglion cells, with NT-3 localized to enteric plexuses, intermuscular basal lamina, and along or between circular and longitudinal smooth muscle cells.

CONCLUSIONS

These data indicate that neurotrophic influences may be involved in ENS development and survival, with potential importance in functional differentiation disorders of the intestinal ENS.

Characterization of the DNA-binding activity of HIV-1 integrase using a filter binding assay

Based on the selective binding of proteins and DNA to distinct filter materials a double-layered dot blot radio assay was developed to evaluate the binding of DNA to HIV-1 integrase. In this assay the DNA-binding was found to be independent of Mn2+ concentration, inhibited by concentrations of Mg2+ above 5 mM, abolished by zinc chelation and inhibited by monoclonal antibodies reacting with either the N-terminal or C-terminal regions of integrase. Atomic absorption spectroscopy revealed the molar ratio between integrase and zinc to be close to 1. It is concluded that both the N-terminal and the C-terminal regions of integrase are involved in DNA-binding and that the reported double-layered dot blot radio assay is well suited for further characterization of the integrase.

Rehbein's anterior resection in Hirschsprung's disease, using a circular stapler

The results of 30 patients with Hirschsprung's disease, operated by Rehbein's anterior resection, have been evaluated. In 26 children the anastomosis was constructed with a circular stapler (Ethicon Proximate ILS) and in 4 it was handsutured. When a stapler was used, technical problems in 4, with a defect in the rings of bowel after firing the instrument, necessitated reinforcing sutures. The level of the anastomosis was significantly lower in the children in which a stapler was used. Eight children were operated by dorsal myectomy (DRM) prior to and 4 after anterior resection. The children with DRM prior to anterior resection had a significantly lower requirement for postoperative dilations. Early postoperative complications included 3.3% mortality, 6.7% enterocolitis, 3.3% anastomotic insufficiency, 3.3% early ileus and 10.0% wound infection. Three patients (10.0%) were operated for postoperative anastomotic stricture, one requiring anastomotic revision and two requiring DRM. At follow-up two children (7.4%) reported constipation with regular requirement for enemas and two (7.4%) reported daily encopresis. Twenty-three patients had 1-5 bowel movements per day and 4 patients had more than 5. In our experience the use of a circular stapler makes it possible to perform a lower anastomosis. We believe that this technique gives a wider and more elastic anastomosis and is technically less difficult to handle than a handsutured anastomosis.

A mechanochemical model for adult dermal wound contraction and the permanence of the contracted tissue displacement profile

The healing of adult mammalian skin wounds involves a complex sequence of spatially and temporally coordinated processes. Wound contraction, by reducing the size of the injury, is an intrinsic component of full-thickness excisional dermal wound healing. The underlying biomechanics of wound contraction, however, are not fully understood, and little is known about the pathogenesis of severe medical conditions known as fibrocontractive diseases. The aim of this work is to investigate a deterministic mathematical model in order to obtain insight into the mechanistic relationships between wound contraction and associated normal and pathological healing processes. The model describes the essential roles of fibroblast and myofibroblast cells, a chemical growth factor and the extracellular matrix which includes type I collagen. The model results are qualitatively consistent with the biology of fibroplasia and wound contraction. It is shown that a contracted state evolves during a (long) transient phase of healing known as "proliferation", while collagen kinetics are fundamental to the considerably longer "remodelling" phase. Some quantitative results, notably on the evolution of wound contraction, compare favourably with experimental data. Application of the model to adult human dermal wound healing in vivo, with a greater understanding of the underlying biological mechanisms involved, may suggest strategies for controlling contraction and fibrocontractive diseases.

The wound healing process in surgical patients evaluated by the expanded polytetrafluoroethylene and the polyvinyl alcohol sponge: a comparison with special reference to intrapatient variability

The aim of this study was to compare two wound healing models in surgical patients with special reference to the intrapatient variability. Two pieces of expanded polytetrafluoroethylene tubing and one perforated silicone tube containing two polyvinyl alcohol sponges were subcutaneously inserted into 28 patients and were removed after 10 (9 to 11) days. The amount of hydroxy-l-proline in two segments of the same piece of expanded polytetrafluoroethylene tubing correlated significantly with each other. Similar results were found for proline. Proline content in each polyvinyl alcohol sponge correlated weakly with each other, whereas no correlation was found between hydroxy-l-proline content in the two polyvinyl alcohol sponges from the same patient. In addition, no correlation was found between leucine in the two adjacent polyvinyl alcohol sponges or between the hydroxy-l-proline/leucine ratio in these same sponges. No concordance could be detected between the averages of hydroxy-l-proline content in the two segments of expanded polytetrafluoroethylene tubing and the hydroxy-l-proline content in the two polyvinyl alcohol sponges from the same person, although an association between the averages of proline in the two pieces of expanded polytetrafluoroethylene tubing and proline content in the two polyvinyl alcohol sponges from the same individual was observed. The measurement error was greater for the polyvinyl alcohol sponges than for the expanded polytetrafluoroethylene tubing implants during the first 10 days after wounding. The expanded polytetrafluoroethylene tubing accumulated 2.5 times more hydroxy-l-proline per length unit than the polyvinyl alcohol sponge. We concluded that the expanded polytetrafluoroethylene implant rather than the polyvinyl alcohol implant is preferred for quantitation of subcutaneous collagen deposition in surgical patients because it accumulates more new tissue and has a lower variability.

Cellular death in neuroblastoma: in situ correlation of apoptosis and bcl-2 expression

Apoptosis is the selective physiologic deletion of cells that are no longer required. Over-expression of the bcl-2 proto-oncogene extends survival of neurons otherwise destined for apoptosis. The unique capacity of neuroblastoma (NB) to undergo spontaneous regression and the prognostic dichotomy of children with this malignancy led us to evaluate bcl-2 expression and apoptosis in NB. An in situ DNA nick-labeling technique to detect apoptotic cells, as well as immunohistochemistry and morphology, were utilized in a selection of NB tumor specimens and in the human fetal sympathetic nervous system. bcl-2 expression was present in all 28 NB tumors examined and in sympathetic ganglia of the human fetus. Measurement of overall bcl-2 expression and of extent of apoptosis correlated with favorable prognosis. In low-stage tumors, bcl-2 expression was most intense in poorly differentiated tumor cells adjacent to fibrovascular stroma. Cells distant from the stroma exhibited increasing degrees of chromaffin differentiation, with apoptosis most evident in bcl-2-negative neuroblasts adjacent to well-differentiated NB cells. The spatial distribution of bcl-2 expression, apoptosis and chromaffin differentiation in favorable-prognosis NB may provide insight into mechanisms of persistent tumor existence or regression.

Association of neurotrophin receptor expression and differentiation in human neuroblastoma

Interactions of the trk family of tyrosine kinase receptors with neurotrophins result in growth and maturational changes in neuronal cells. The continued progression, maturation, or regression of neuroblastoma, an embryonal, sympathetic nervous system-derived tumor of infants and children, might be governed by neurotrophic influences. Immunocytochemistry was utilized to evaluate TrkA, TrkB, and TrkC protein expression at the cellular level in the developing human fetal sympathetic nervous system and in a selection of neuroblastoma tumor specimens. TrkA and TrkC expression was identified in sympathetic ganglia and within the adrenal medulla, with intense TrkB expression restricted to paraganglia, of the normal developing human sympathetic nervous system. In neuroblastoma, pp140trkA expression correlated positively with favorable tumor stage (P = 0.0027) and favorable outcome (P = 0.026). No statistically significant correlation of TrkC expression with outcome was evident; however, both TrkA and TrkC expression was most apparent in tumor cells of increased differentiation. TrkB expression was primarily localized to cells within the fibrovascular tumor stroma. A model of neurotrophin receptor expression and neurotrophin reactivity with differentiation is proposed. The existence and spatial distribution of neurotrophin receptors in neuroblastoma lend supportive evidence that neurotrophic influences may be involved in tumor persistence or regression.

Self-cloning in filamentous fungi: application to the construction of endothiapepsin overproducers in Cryphonectria parasitica

The filamentous ascomycete fungus Cryphonectria parasitica naturally secretes endothiapepsin, an aspartic proteinase. It is cultured on a commercial scale as a source of the milk-clotting enzyme for cheese making. Our objective was to increase enzyme production of an industrial C. parasitica strain by a new technique of self-cloning; it consisted in the screening for transformants producing higher levels of endothiapepsin and having integrated only the DNA fragment of interest. Such genetically improved strains that are devoid of any foreign genes should be more readily acceptable for the production of food-grade enzymes.

Neurological dysfunction above cele level in children with spina bifida cystica: a prospective study to three years

The aim of this study was to characterize the neurological dysfunction above the cele level in children with spina bifida cystica. 22 neonates were investigated prospectively to a median age of three years. Before primary closure of the spinal malformation and at three and 18 months of age, MRI and inspection of vocal cord function were performed. The children were also assessed by a physical therapist at 12 and 24 months, 19 children had a Chiari malformation, 18 children developed neurological dysfunction above the cele level. Children with signs of isolated motor impairment stabilized or improved during the second year. Six children developed severe functional impairment of respiration, feeding and motor performance within the first three months of life. Severe neurological signs/symptoms were associated with myeloschisis, clinical signs of a tethered cord and recurrent periods of shunt dysfunction.

[Methods for measurement of wound extent]

Healing is a biologically complicated process, which is difficult to measure objectively. Several products and pharmaceuticals have been applied to the treatment of both acute and chronic wounds. There are, however, only few well-documented studies of the effect and many recommendations are based on casuistries, undocumented studies or in vitro studies. One of the most prominent problems has been the lack of exact measurements. This article describes the available clinical measurement parameters and discusses their strengths and weaknesses. The following methods of measurement are described: Wound surface area (WSA), wound area (WA), and volume (VOL). A stratification of wounds before measuring is suggested depending on aetiology and form (volume or surface wounds). The most sensitive measure for assessment of wound healing is recommended. From a clinical point of view the transition from a volume to surface wound is not distinct, and therefore WA is recommended as the most relevant measurement during wound healing.

On the frequency of chromosome exchanges in a control population measured by chromosome painting

Chromosome painting has been shown to be a valid and rapid method for quantifying structural chromosome rearrangements in human lymphocytes. The method is particularly useful for detecting stable aberrations which are difficult and expensive to quantify with classical methods. The inherent stability of translocations has enabled them to be used as a biodosimeter for chronic and temporally displaced exposure to radiation. Translocations may also be useful for quantifying chronic exposure to other environmental agents which may result in an accumulation of cytogenetic damage with age. Most exposures are chronic and occur at low rates, and conventional cytogenetic methods such as dicentric analysis are not expected to be informative. To understand the extent to which age and lifestyle factors impact the frequency of stable aberrations, we have performed chromosome painting on metaphase-arrested lymphocytes cultured from 47 healthy adults ranging in age from 19 to 77 years, and from umbilical cord blood obtained from eight healthy full-term infants. All subjects had previously been screened to eliminate those who had received significant occupational or accidental exposure to radiation or chemicals, and none had received chemo- or radiotherapy. Due to the infrequent occurrence of stable aberrations in peripheral lymphocytes, we analyzed the equivalent of more than 1100 metaphase cells from each of these 55 people. An average of one cell in 130 (0.77%) was observed to have a translocation or a stable insertion. A significant relationship between stable aberrations and the square of the age is apparent (R2 = 0.69, Y = 0.0615 + 0.000304 age2; p < 0.00001). These results support the hypothesis that stable aberrations accumulate with time, and are likely to integrate adverse environmental exposure.

Activity of cyclosporins as resistance modifiers in primary cultures of human haematological and solid tumours

The semiautomated fluorimetric microculture cytotoxicity assay (FMCA) was used for evaluation of the ability of cyclosporin A (CsA) and its novel non-immunosuppressive derivative SDZ PSC 833 (PSC) to modify the response to doxorubicin or vincristine in vitro in different haematological and solid human tumour types. Primary cultures of 322 tumour samples were analysed. Both cyclosporins showed resistance-modifying activity in all haematological tumours tested, and in solid tumours activity was observed in ovarian carcinoma and childhood tumours. Little or no effect was found in the remaining tumour types, including breast, renal and adrenal cortical carcinomas and adult sarcomas. In most of the responsive cases the interaction between the modifier and the cytotoxic drug was synergistic. There was a tendency to higher activity in samples from previously treated patients, and an inverse relationship between degree of cytotoxic drug resistance and resistance-modifying activity was noted. No difference in potency between CsA and PSC could be discerned. The results indicate differential in vitro resistance-modifying activity of the cyclosporins depending on tumour type. The results also suggest that treatment with resistance modifiers should be considered also for primary therapy of drug-sensitive tumours. Drug resistance assays such as the FMCA may become useful in preclinical evaluation of resistance modifiers.

Sacrococcygeal teratoma in Sweden: a 10-year national retrospective study

Thirty-two children with sacrococcygeal teratoma have been treated during the last 10 years (1980 to 1989) in Sweden. A retrospective study was performed in four departments of pediatric surgery that treat sacrococcygeal teratomas in children from the whole of Sweden. Prenatal and perinatal histories were reviewed together with interval to diagnosis, Altman classification, histology, and serum alpha-fetoprotein. Details of surgical management +/- adjuvant chemotherapy and outcome of patients were also documented. In 8 patients the teratoma was diagnosed prenatally by ultrasonography and there was one postoperative death in this group. Multiagent chemotherapy was used in all but one of 11 patients with malignant teratomas (in 8 of them a cisplatin, bleomycin, vinblastine combination). Only one patient with a malignant tumor treated by single-agent chemotherapy died, 8 others were still alive and tumor-free after 1 to 9 years (mean time, 5.4 years). Two patients developed late relapses and were treated by surgical resection. Metastases occurred in five of the 11 malignant tumors, one at presentation and in four patients 10 to 29 months following surgery. All relapses had distant metastases as well as local disease. Serum alpha-fetoprotein was used in monitoring some of these patients.

Gastrin-releasing peptide stimulation of corticotropin secretion in male rats

Gastrin-releasing peptide (GRP; mammalian bombesin) may be involved in the neuroendocrine regulation of pituitary hormone secretion. We investigated the effect of GRP on ACTH secretion in conscious male rats. GRP (7-700 pmol) stimulated ACTH secretion dose-dependently after intracerebroventricular (icv) administration but had no effect after iv administration. GRP infused icv in a dose of 7 pmol, which alone increased ACTH 1.5-fold, potentiated the ACTH-releasing effect of arginine vasopressin (AVP; 80 pmol iv) and corticotropin-releasing hormone (CRH; 100 pmol iv). A higher dose of GRP (70 pmol icv), which stimulated ACTH secretion 2-fold, potentiated the effect of 80 and 400 pmol AVP iv, but had only additive effect on the ACTH response to 800 pmol AVP iv or 100 pmol CRH iv. GRP infused iv in a dose of 210 pmol, which in itself had no effect on ACTH secretion, potentiated the ACTH-stimulating effect of AVP and CRH approximately 2.5-fold. The effect of GRP (icv or iv) on AVP or CRH-stimulated ACTH release was only slightly smaller than the effect of combined administration of AVP and CRH (80 + 100 pmol iv). The ACTH-stimulating effect of GRP (700 pmol icv) was inhibited about 60% by pretreatment with either CRH or AVP antiserum and prevented by combined pretreatment with the antisera. The results indicate that: 1) GRP affects ACTH secretion indirectly at a suprapituitary level--possibly in the hypothalamus--by stimulating the release of AVP and CRH to the pituitary portal blood; and 2) GRP acts directly at the pituitary level to augment the effect of AVP and CRH on the corticotrophs. We suggest that GRP is involved in the multifactorial regulation of ACTH secretion.

Multiple intestinal duplications in a child with thoracic myelomeningocele and hydrocephalus

An infant with thoracic spina bifida, myelomeningocele and hydrocephalus was found to have intrathoracic gastric duplication and noncontiguous tubular duplication along two-thirds of the small bowel. The myelomeningocele was closed and the hydrocephalus relieved with a shunt. The intrathoracic duplication was excised in toto and the intra-abdominal malformation successfully treated by stripping the entire mucosal tube from within the duplication.

Urethral reconstruction with a new synthetic absorbable device. An experimental study

Four centimeters of the canine urethra was replaced by a graft consisting of a polyglactin fiber mesh tube, coated with polyhydroxybutyric acid. Microscopic examination 8-12 months later showed almost complete regeneration of the urethral epithelium and the adjacent connective tissue. The neo-urethra was patent and there were no anastomotic strictures, nor was there any inflammatory reaction around the urethra. The validity of this concept in humans remains to be proved.