Comparison of the expression of fibrosis-associated genes in glomeruli after renal transplantation between conventional cadaveric and non-heart-beating donors

BACKGROUND

The main difference between cadaveric heart-beating donors and non-heart-beating donors (NHBDs) is the degree of warm ischaemia to which the kidney is subjected. This study was designed to see if this affected the expression of fibrosis-associated genes in the early period after transplantation.

METHODS

A series of 29 cadaveric and 19 NHBD renal transplants was studied. Patients underwent protocol needle-core renal transplant biopsies at 1 week, 3 months and 6 months after transplantation. At least two individual glomeruli were isolated from each biopsy. Messenger RNA was extracted and genes of interest were amplified by reverse transcriptase-polymerase chain reaction, then quantified in an enzyme-linked immunosorbent assay system.

RESULTS

Delayed graft function was common in NHBD (17 of 19) compared with cadaveric transplants (six of 29) (P < 0.0001). Acute rejection rates were similar. The level of tissue inhibitor of metalloproteinase 1, an inhibitor of extracellular matrix degradation, was higher in kidneys from NHBDs at 1 week (P = 0.02). There were no other statistically significant differences in the expression of fibrosis-associated genes between the two groups.

CONCLUSION

Although the increased ischaemic injury in kidneys retrieved from NHBDs leads to a higher rate of delayed graft function, this does not translate into increased expression of fibrosis-associated genes after the first week.

Intragraft expression of transforming growth factor beta1 gene in isolated glomeruli from human renal transplants

BACKGROUND

Experimental evidence suggests that transforming growth factor (TGF) beta1 is a fibrogenic cytokine. The histopathological changes of chronic renal allograft nephropathy are dominated by fibrotic changes and TGF-beta may have an important aetiological role. This study investigated the relationship between intragraft TGF-beta gene expression and extracellular matrix protein deposition in human renal allografts.

METHODS

Sixteen cadaveric renal transplant recipients immunosuppressed with cyclosporin and steroids were studied. Individual glomeruli were isolated from protocol needle-core biopsies and, following messenger RNA extraction, intragraft gene expression was studied by reverse transcriptase-polymerase chain reaction. Collagen III deposition in these renal transplant biopsies was examined by immunohistochemistry and quantified by computerized histomorphometry.

RESULTS

There was a positive correlation between renal cortical collagen III immunostaining and the levels of glomerular complementary DNA for TGF-beta1.

CONCLUSION

TGF-beta1 is a profibrotic influence in human renal transplants. The methods described should prove of benefit in investigating the mechanisms of chronic renal allograft damage.

Isolation and growth physiology of novel thermoactinomycetes

A total of 34 thermophilic isolates identified as members of the genus Thermoactinomyces by a range of chemotaxonomic, microscopic and determinative biochemical tests, were isolated from two acid soils. Growth studies in shake flask and fermenter identified the isolates to be moderately acidophilic with growth occurring between pH 4.5 and 6.0 with optima at pH 5.0. The isolates differed considerably from known Thermoactinomyces cultures in their pH profile, colony morphology and in several biochemical tests. Extracellular enzyme activities are identified and partially characterized in terms of their thermostability, pH and temperature profiles from crude supernatant fluid samples. Optimal protease, amylase and pullulanase activity was observed at pH 5.0-5.5 and 75-80 degrees C with each showing T(50) values of 10, 30 and 30 min, respectively. A highly thermotolerant extracellular esterase was also identified which retained 50% activity after 8 h at 90 degrees C. This is the first report of an acidophilic member of the genus Thermoactinomyces.

Keratinocyte growth factor ameliorates radiation- and bleomycin-induced lung injury and mortality

Keratinocyte growth factor (KGF) is a growth factor for type II pneumocytes. Type II pneumocyte hyperplasia, a common reaction to lung injury, has been postulated to play an important role in lung repair. The potential protective effect of KGF was therefore studied in rat models of radiation- and bleomycin-induced lung injury. Intratracheal instillation of KGF (5 mg/kg) 72 and 48 hours before 18 Gy of bilateral thoracic irradiation did not significantly improve survival, although histology showed less pneumonitis and fibrosis in KGF-pretreated as compared with control-irradiated rats. Intratracheal pretreatment with KGF in rats receiving intratracheal bleomycin (2.5 U) improved survival at 3 weeks to 100% (20/20 rats) from 40% (8/20 rats) in controls. All KGF-pretreated rats receiving bleomycin were well at 3 weeks and without histological evidence of pulmonary fibrosis whereas the 8 surviving control rats exhibited severe respiratory distress. Finally, in the most lethal challenge to the lung, rats pretreated with intratracheal KGF or saline were challenged with a combination of bleomycin (1.5 U) and bilateral thoracic irradiation (18 Gy). KGF-pretreated rats did not begin to die or show signs of respiratory distress until 7 weeks, whereas all saline-pretreated control rats receiving radiation and bleomycin died within approximately 4 weeks with severe respiratory distress and weight loss. In conclusion, radiation- and bleomycin-induced pulmonary injury and respiratory death are ameliorated by KGF pretreatment, suggesting a protective role for KGF-induced type II pneumocyte proliferation in lung injury.

Improved outcome of surgical flaps treated with topical dimethylsulfoxide

OBJECTIVE

The objective of this study was to analyze the effect of dimethylsulfoxide (DMSO) on skin flap viability.

BACKGROUND

Dimethylsulfoxide has been shown to decrease necrosis of random skin flaps in the rat model, but no human studies have been performed. The authors performed a randomized, prospective study on the effect of DMSO on skin flap viability in patients undergoing mastectomy and inguinal lymphadenectomy.

METHODS

Twenty-four patients had topical 60% DMSO applied to their flaps every 4 hours x 10 days after operation and 27 patients had operation alone. The maximum area of flap ischemia was traced by a masked observer and measured by cut and weigh technique. Significance of differences between the treatment and control group was determined by Student's test.

RESULTS

The mean area of ischemia for the DMSO group was 16.33 U versus 44.93 U for the control group. This difference was statistically significant (p = 0.01).

CONCLUSIONS

The authors conclude that topical application of DMSO reduces skin flap ischemia in humans and recommend its use after operation in which skin flaps are created.

AAMP, a newly identified protein, shares a common epitope with alpha-actinin and a fast skeletal muscle fiber protein

AAMP (angio-associated migratory cell protein) shares a common epitope with alpha-actinin and a fast-twitch skeletal muscle fiber protein. An antigenic peptide, P189, derived from the sequence of AAMP was synthesized. Polyclonal antibodies generated to P189 readily react with AAMP (52 kDa) in brain and activated T lymphocyte lysates, alpha-actinin (100 kDa) in all tissues tested, and a 23-kDa protein in skeletal muscle lysates. The antibody's reactivity for alpha-actinin can be competed with the purified protein. Activation of T lymphocytes does not alter the degree of alpha-actinin reactivity with anti-P189 as it does for AAMP's reactivity in these lysates. Competition studies with peptide variants show that six amino acid residues, ESESES, constitute a common epitope in all three proteins in human tissues. The antigenic determinant is continuous in AAMP but discontinuous (or assembled) in alpha-actinin. alpha-Actinin does not contain this epitope in its linear sequence so reactivity is attributed to an epitope formed by its secondary structure. Limited digestion of the reactive proteins with thermolysin destroys anti-P189's reactivity for alpha-actinin while reactivity for recombinant AAMP is retained. Specificity of anti-P189 for human skeletal muscle fast fibers seen on immunoperoxidase staining may be explained by anti-P189's reactivity with a 23-kDa protein found only in skeletal muscle lysates. Its pattern of reactivity is the same as that obtained using monoclonal anti-skeletal muscle myosin heavy chain in type II (fast-twitch) fibers.

Severe intravascular hemolysis associated with brown recluse spider envenomation. A report of two cases and review of the literature

Envenomation by the brown recluse spider (loxoscelism) is classically associated with a necrotic ulcer. Systemic manifestations occur in a minority of cases, but are generally mild and self-limited. The hematologic complications of brown recluse spider bite range from mild hemolysis to fulminant intravascular hemolysis with or without evidence of disseminated intravascular coagulation. Intravascular hemolysis is a rare but occasionally lethal complication of brown recluse spider envenomation. This article presents two cases of severe hemolysis associated with loxoscelism occurring in two young women in Memphis, Tennessee. The second documented death in an adult from severe hemolysis due to a brown recluse spider bite is reported. A review of the literature emphasizing the pathogenic mechanisms of spider bite hemolysis is also included.

Identification of a new immunoglobulin superfamily protein expressed in blood vessels with a heparin-binding consensus sequence

A novel immunoglobulin-type protein expressed in blood vessels has been identified. The cDNA for AAMP (angio-associated, migratory cell protein) was first isolated from a human melanoma cell line during a search for motility-associated cell surface proteins. Upon analysis of the tissue distribution of AAMP, it was found to be expressed strongly in endothelial cells, cytotrophoblasts, and poorly differentiated colon adenocarcinoma cells found in lymphatics. The sequence of AAMP predicts a protein (M(r) 49,000) with distant identity (25%) to known proteins. It contains immunoglobulin-like domains [one with multiple homologies to deleted in colon carcinoma (DCC) protein], the WD40 repeat motif, and a heparin-binding consensus sequence. A 1.6-kilobase mRNA transcript of AAMP is detected in tissue culture cell lines and tissues. Affinity-purified polyclonal antibodies, anti-recombinant AAMP, and anti-peptide 189 (AAMP derived) recognize a M(r) 52,000 protein in human tissue and cellular extracts. The protein size is in keeping with the mRNA and predicted sequence. The AAMP-derived peptide, P189, contains a heparin-binding domain (dissociation constant, 14 pmol) and mediates heparin-sensitive cell adhesion. The shared expression of AAMP in endothelial cells, trophoblasts, and tumor cells implies a common function in migrating cells.

Detection and identification of novel actinomycetes

The actinomycetes are well known as a group of filamentous, Gram-positive bacteria that produce many useful secondary metabolites, including antibiotics and enzymes. Although they have been intensively studied for both theoretical and practical objectives, there is much scope for developing our basic knowledge of the means of detection and isolation of these microbes. This session concentrated on new methods for the detection and identification of novel actinomycetes from a range of environments. Approaches to the detection of actinomycetes ranged from investigations of neglected habitats and extreme environments (e.g. alkaline soils and oil drills) to the analysis of DNA extracted from the environment and use of specific phages. The continuing problems of the identification of actinomycete isolates were also considered. Topics discussed included use of phage typing, DNA probes, and correlation between phenetic and genotypic species of Streptomyces.

Actinomycetes as agents of biodegradation in the environment--a review

The diversity of form in the Actinomycetales is well-recognised, due to the sustained generation of environmental isolates for pharmaceutical screening. Actinomycetes isolated from soil and related substrates show primary biodegradative activity, secreting a range of extracellular enzymes and exhibiting the capacity to metabolise recalcitrant molecules. Composting is one process which relies heavily on such prolific actinomycete activity. Amongst actinomycetes in soil, there are examples of different strategies, from cycles of rapid proliferation and sporulation to the maintenance of populations by prolonged slow growth and scavenging, and the evidence for this is examined. The mechanisms of lignocellulose degradation by actinomycetes are discussed in relation to functional conservation within the group, and correlations with those described in other bacteria and fungi.

Staging of colorectal cancer

A chronological overview of the various staging systems for colorectal cancer is presented in an effort to demonstrate the reason for the current state of confusion. The Dukes 1932 system is considered to be the gold standard because of its simplicity and accuracy and is the system most often referred to in the literature. Number of positive nodes and depth of invasion are two variables that have been found to be predictors of survival. In the future, other prognostic factors such as nuclear morphology, flow cytometric characteristics, histological grade, and vascular or lymphatic invasion may also be entered into the staging equation. Use of the TNM system at this time is recommended since it most completely describes appropriate prognostic factors and allows conversion of other staging systems into a common format. Future modifications could logically evolve from the TNM system.

Use of polyvalent phage for reduction of streptomycetes on soil dilution plates

An isolation method was developed in which prior to inoculation soil suspensions were exposed to suspensions of polyvalent phage isolated to Streptomyces spp. The phage susceptibility of streptomycetes provided a selective means of reducing streptomycetes on isolation plates subsequent to inoculation, and this reduction was persistent after long incubation periods. The efficiency and applicability of the method developed were checked with different samples from a range of sources. The increased chances of development of other genera after the reduction of streptomycetes on soil dilution plates were assessed.

Perineal hidradenitis suppurativa: presentation of two unusual complications and a review

Two patients with advanced perineal hidradenitis suppurativa, complicated by fecal incontinence and squamous cell carcinoma, are presented. The first patient was a 58-year-old man who had a 30-year history of chronic recurring perianal abscesses and perineal sinuses. At the time of presentation, he had extensive perineal suppurative disease, and scarring and fixation of the anal sphincters with resultant fecal incontinence. He was treated with wide excision and skin graft closure. The second patient was a 27-year-old man with an 11-year history of recurrent gluteal abscesses and perineal sinuses. At the time of presentation, his inflammatory disease was only mildly active, but he had a nonhealing gluteal lesion. The nonhealing lesion was diagnosed as a squamous cell carcinoma and was managed with wide excision and primary closure. The inflammatory disease was excised and grafted. Complications of advanced hidradenitis suppurativa can be debilitating and life threatening. We review the etiology, pathophysiology, complications, and treatment options of hidradenitis suppurativa, including a literature review of the association with malignancy. We propose that the incidence of disabilities and complications may be reduced by early diagnosis and treatment, by emphasis on prevention of recurrence, and by more aggressive surgical intervention for recurrent and extensive disease.

Treatment of nonendocrine gastrointestinal disorders with octreotide acetate

Somatostatin and its longer-acting analog, octreotide acetate, can be used effectively for the treatment of nonendocrine gastrointestinal disorders. Octreotide has been shown to decrease pancreatic fistula output by suppressing exocrine pancreatic function. We believe that octreotide acetate may be useful to prophylaxis against the development of pancreatic fistulas following pancreatic resection and may reduce the enzymatic and volume output of established pancreatic fistulas. We also have shown that administration of octreotide acetate 2 hours before a high carbohydrate test meal reduces gut peptide levels, which increase following meal ingestion in patients with the dumping syndrome. Reduction of circulating peptides in these patients may slow gut motility and improve glucose regulation, thus, providing relief of postvagotomy dumping symptoms.

Oral habilitation of the child with no response on brainstem audiometry

Children without an auditory brainstem evoked response can benefit from an auditory-oral hearing habilitation program. This study focuses on 31 such children enrolled at the Houston School for Deaf Children. Eleven had excellent auditory-oral skills, with language ability equal to normal-hearing children of a similar age, and speech easily intelligible to a familiar listener. A statistically significant factor associated with success was hearing acuity at 250 Hz. Other important factors included age at enrollment at the school, duration of enrollment, degree of parental support, and absence of middle ear disease.

Effect of octreotide acetate on pancreatic exocrine function

Somatostatin and its analogs have been shown to inhibit both pancreatic endocrine and exocrine function. We hypothesized that octreotide acetate (Sandostatin), a somatostatin analog, decreases the pancreatic flow rate through a peptide-mediated mechanism and alters pancreatic fluid composition by inhibiting carbonic anhydrase action and circulating peptide levels. To test this hypothesis, we collected pancreatic fluid from six patients (four with pancreatic fistulas and two with pancreatic drains after pancreatic resection). Pancreatic fluid volume and chloride, sodium, potassium, amylase, lipase, and bicarbonate levels were measured before and after octreotide acetate therapy. Octreotide acetate reduced pancreatic fluid output by a mean of 75 percent (p less than 0.05), increased chloride concentration by 21 percent (p less than 0.05), and reduced bicarbonate content by 45 percent (p less than 0.05). Sodium levels were unchanged, but the potassium concentration was increased by 14 percent (p less than 0.05). Total amylase and lipase production per 24 hours was decreased by 63 percent and 27 percent, respectively (differences not significant). Somatostatin may be useful in the treatment of established pancreatic fistulas and may be a useful prophylactic tool to prevent postoperative fistula formation.

Detecting aberrant strains in bacterial groups as an aid to constructing databases for computer identification

Computer assisted identification systems require that databases on the test results of the species are of high quality. One reason for poor quality is the inadvertent inclusion of strains that do not belong to a taxon; this can readily occur in groups where ancillary criteria (e.g. serology) are not available. A possible strategy is to exclude strains that are very atypical in their properties, i.e. that are very outlying, provided an objective criterion can be used. A computer program, OUTLIER, for the detection of outlying strains in bacterial clusters was evaluated. A brief description of the theory and operation of the program is given. The program uses as an objective criterion the degree to which the strain data fits a chi-square. This allows easy identification of aberrant strains that should be excluded in constructing a database. The program utilizes 1.0 data and calculations are based upon a choice of one of four identification coefficients. The relative merits of these four coefficients were examined for eight sets of bacterial data. Two of the coefficients, -log10 Willcox likelihood and Taxonomic distance squared appear to show little significant differences and we recommend these for routine work, with the first being the more useful. The Pattern distance squared was useful in indicating where atypical strains may be metabolically less active or slow-growing members of a cluster rather than true outliers. The Variance-weighted Taxonomic distance squared behaved anomalously and we do not recommend it.

New probability matrices for identification of Streptomyces

The character state data obtained for clusters defined in a previous phenetic classification were used to construct two probabilistic matrices for Streptomyces species. These superseded an original published identification matrix by exclusion of other genera and the inclusion of more Streptomyces species. Separate matrices were constructed for major and minor clusters. The minimum number of diagnostic characters for each matrix was selected by computer programs for determination of character separation indices (CHARSEP) and a selection of group diagnostic properties (DIACHAR). The resulting matrices consisted of 26 phena x 50 characters (major clusters) and 28 phena x 39 characters (minor clusters). Cluster overlap (OVERMAT program) was small in both matrices. Identification scores were used to evaluate both matrices. The theoretically best scores for the most typical example of each cluster (MOSTTYP program) were all satisfactory. Input of test data for randomly selected cluster representatives resulted in correct identification with high scores. The major cluster matrix was shown to be practically sound by its application to 35 unknown soil isolates, 77% of which were clearly identified. The minor cluster matrix provides tentative probabilistic identifications as the small number of strains in each cluster reduces its ability to withstand test variation. A diagnostic table for single-membered clusters, constructed using the CHARSEP and DIACHAR programs, was also produced.

The ecology of antibiotic production

Over the last 40 years, there has been a steady supply of novel, useful antibiotics produced by microbes isolated from soil and other natural environments. The increased efficiency of screening procedures in the last decade has played a major part in maintaining this supply. However, the selection and sampling of natural environments are still essentially random processes. The main reasons for this are an almost total lack of knowledge of the significance of antibiotics in nature, deficiencies in the taxonomy of antibiotic-producing microbes and its application, and lack of information about the distribution and ecology of known or potential antibiotic producers. The origins of these problems are discussed and some possible solutions are suggested.