De novo hepatitis with autoimmune antibodies and atypical histology: a rare cause of late graft dysfunction after pediatric liver transplantation

BACKGROUND

Late graft dysfunction after orthotopic liver transplantation is commonly due to chronic rejection, recurrence of primary disease, sepsis, lympho-proliferative disease, or vascular or biliary complications. Herein we describe a subset of pediatric liver transplant patients in whom late graft dysfunction was associated with autoimmune markers, bile ductular proliferation, and portal infiltrates, which progress to fibrosis. This subset of patients has not been previously described.

METHODS

Six of the 115 children followed for greater than 5 years after transplantation developed this unusual form of graft dysfunction. All children were on a low-dose single immunosuppressive therapy (mean trough cyclosporine concentration 89 microg/L) and had been tapered off steroids for a median duration of 1.5 year. Liver biopsies were performed in all children to evaluate the graft dysfunction, and the histologic findings were interpreted by an experienced hepato-pathologist. All patients were tested for antibodies to hepatitis C virus, hepatitis B surface antigen, and IgM antibodies to hepatitis A. Smooth muscle antibody, antinuclear antibody, and antibody to liver/kidney microsome type 1 were sought by indirect immunofluorescence. International Autoimmune Hepatitis Group scores were calculated. All patients underwent ultrasonography with doppler studies at the onset of graft dysfunction. Three patients with marked bile duct proliferation on histology had cholangiograms.

RESULTS

Histology in all patients showed mononuclear cell infiltrates in the portal area with interface hepatitis, portal fibrosis, and ductular proliferation without duct damage or loss. All six patients had positive antinuclear antibody or smooth muscle antibody titers. Viral studies for hepatitis A, B, and C were negative in all patients. On the International Autoimmune Hepatitis Group scoring system, five patients had probable autoimmune hepatitis (score of 10-15) and one had definite autoimmune hepatitis (score > 15) at the onset of graft dysfunction. All were treated with azathioprine and prednisone similar to treatment for autoimmune hepatitis. However, despite aggressive treatment, four patients developed bridging portal fibrosis resulting in graft loss in two patients.

CONCLUSION

This clinical constellation is associated with worse outcome then that previously described for pediatric patients with posttransplantation de novo autoimmune hepatitis. Further studies are needed to find an optimal treatment regimen for these patients.

The design of phenylglycine containing benzamidine carboxamides as potent and selective inhibitors of factor Xa

Factor Xa, a critical serine protease in the blood coagulation cascade, has become a target for inhibition as a strategy for the invention of novel anti-thrombotic agents. Here we describe the development of phenylglycine containing benzamidine carboxamides as novel, potent and selective inhibitors of factor Xa.

Liver transplantation at the University of Chicago

Since our 1995 report, improvements in patient survival after liver transplantation have widened indications for liver transplantation and led to a greater imbalance between donor supply and need. The organ shortage is the major barrier to liver transplantation at this time. Despite expanded donor criteria, there has been only a marginal increase in the number of liver transplants performed nationally. We have used several approaches to decrease the demand for organs in both adults and children. Our center was one of the first institutions to use reduced-size, living-donor, and split liver transplants routinely. The use of reduced-size liver transplants has decreased as the use of split liver transplantation has increased. Both split liver transplantation and living donor transplantation play an important role in caring for pediatric and adult patients with end-stage and fulminant liver disease. We have concentrated our recent efforts to optimizing the technical aspects of living donor transplantation in order to decrease the need for retransplantation and further organ use. These efforts have dramatically increased graft survival. We have also focused attention on treating patients prior to transplantation in an attempt to eventually abrogate the need for traditional transplantation in some disease processes. With the use of hepatocytes and liver assist devices, we have demonstrated that we can provide a level of metabolic support not achieved with traditional medical therapy for patients with fulminant hepatic failure. As further advances in these therapies are made over the next several years, a concerted effort to bridge patients to recovery will be made. As liver transplantation has become more standardized, it has opened the door to more challenges. We have used liver transplantation in combination with cardiac transplantation to care for selected patients with end stage disease of both organs. This has been remarkably successful for the 3 patients transplanted at the University of Chicago. The immunologic benefit of this combination appears to be a decreased incidence of cardiac rejection. We have standardized the technical components of this combined operation to allow for optimal organ function and patient survival.

Modern immunosuppression

The current treatment of posttransplant lymphoproliferative disease (PTLD) includes prophylaxis at the time of transplant, decreasing or stopping immunosuppresion and initiation of antiviral therapy in patients with polymerase chain reaction or clinical evidence of PTLD, and judicial reintroduction of immunosuppression in patients who have cleared their PTLD and have begun to have rejection. The pharmacology, pharmacokinetics, notable side effects, and toxicities of the immunosuppressive agents are described in this article. At the conclusion of each section the author's current practice with these agents and treatment strategies are described.

Combined liver and kidney transplantation in children

BACKGROUND

Preexisting renal dysfunction has been reported to significantly increase the morbidity and mortality associated with orthotopic liver transplantation (OLT). OLT alone has been recommended for adults and children with end-stage liver disease and reversible causes of renal failure (i.e., hepatorenal syndrome), whereas combined liver and kidney transplantation (LKT) has been shown to be an effective treatment for adults with combined end-stage liver and kidney disease. The purpose of this study was to examine the role of LKT in children.

METHODS

Between October of 1984 and 1997, 385 children less than 18 years of age underwent OLT at the University of Chicago. During this same time period 12 patients underwent LKT. Data were gathered by retrospective review of the patients medical records and by interviews conducted with the patients' families.

RESULTS

Actuarial patient survival was comparable for children who underwent OLT alone and LKT (69% versus 67% at 5 years). All allograft losses in the LKT group were the result of patient death and occurred within the first 90 postoperative days. Factors associated with decreased patient survival included severity of illness as reflected by United Network of Organ Sharing status and LKT after failed OLT or cadaveric renal transplant.

CONCLUSIONS

In children with concomitant endstage liver and kidney disease, LKT can be considered an effective therapeutic option in selected patients. Long-term patient survival in patients undergoing LKT is comparable to that of patients with normal renal function undergoing OLT alone.

Plaque radiotherapy for management of ciliary body and choroidal melanoma with extraocular extension

PURPOSE

To report the results of plaque radiotherapy of ciliary body and choroidal melanoma with extraocular extension.

METHODS

This retrospective study of 17 eyes of 17 patients with ciliary body and choroidal melanoma demonstrated extraocular extension that was clinically evident but less than 3 mm in thickness. In 14 eyes, the extraocular extension was located anteriorly and in three posteriorly. The outcome of plaque radiotherapy in terms of intraocular and extraocular tumor responses and the development of metastasis were analyzed.

RESULTS

At a median follow-up of 63 months (range, 23 to 164 months) after plaque radiotherapy, all patients showed control of both the intraocular and extraocular components of ciliary body and choroidal melanoma. In no case did the intraocular or extraocular portion of the tumor relapse. The initial median thickness of the intraocular component was 4.9 mm, and the final median thickness was 2.4 mm. The initial median thickness of the extraocular component was 2.0 mm, and the final median thickness was 1.0 mm. The initial median basal diameter of the extraocular component was 3.5 mm, and the final median basal diameter was 2.0 mm. Of 17 patients, 11 (10 with anterior and one with posterior extraocular extension) showed partial regression in base and thickness of the extraocular extension, and in six there was little or no change. In those with anterior extrascleral extension, the sclera remained intact without clinically observable necrosis, and the scleral fibers were gradually more visible as the tumor regressed. Three patients (18%) died of metastatic melanoma at a median interval of 38 months after plaque radiotherapy.

CONCLUSIONS

Plaque radiotherapy appears to be a reasonable treatment option for selected cases of ciliary body and choroidal melanoma with clinically visible extraocular extension less than 3 mm in thickness.

Percutaneous treatment of portal venous stenosis in children and adolescents with segmental hepatic transplants: long-term results

PURPOSE

To evaluate the long-term effectiveness of the percutaneous treatment of portal venous stenoses in children and adolescents with reduced-size hepatic transplants.

MATERIALS AND METHODS

During the past 5 years, percutaneous transhepatic balloon venoplasty was attempted in 25 children and adolescents with anastomotic portal venous stenoses that occurred after reduced-size hepatic transplantation. All procedures were performed with direct puncture of the intrahepatic portal vein and with subsequent balloon dilation. Intravascular stents were deployed in patients with suboptimal results after dilation or with recurrent stenoses.

RESULTS

Percutaneous venoplasty was technically successful in 19 of 25 patients. In the remaining six patients, portal venous occlusion precluded access to the extrahepatic portal vein. Intravascular stents were deployed in 12 patients for "elastic" (n = 5) or recurrent (n = 7) stenoses. Seven patients who underwent successful venoplasty without stent placement have required no further intervention. All stents have remained patent without further intervention. Portal venous patency has been maintained for 5-61 months (mean time, 46 months) in all 19 patients.

CONCLUSION

Percutaneous treatment of portal venous stenoses is effective and long lasting in children with reduced-size hepatic transplants. In patients with elastic or recurrent lesions, portal venous stents have excellent long-term primary patency despite continued patient growth. Successful, percutaneous transhepatic venoplasty eliminates the need for surgical revision, portacaval shunting, or repeat transplantation.

A new minimally invasive technique to show nerve ischaemia in diabetic neuropathy

AIMS/HYPOTHESIS

Experimental studies have shown that abnormalities of nerve microcirculation are important factors in the pathogenesis of diabetic neuropathy but there have been few clinical studies. We have applied microlightguide spectrophotometry to measure intravascular oxygen saturation (HbO2%) and blood flow in human sural nerve.

METHODS

We studied ten patients with mild-moderate sensory motor diabetic neuropathy, nine patients without neuropathy and nine control subjects. We took 300 measurements of oxygen saturation under direct visual control through a 1.9 mm rigid endoscope over three regions of the nerve. Spectrophotometric measurements of nerve fluorescence were taken after an intravenous injection of sodium fluorescein and the rate of increase in nerve fluorescence (rise time) was used as an indicator of nerve blood flow.

RESULTS

Nerve oxygen saturation was reduced in patients with neuropathy compared with control subjects (67.1 +/- 2.2% vs 76.7 +/- 2.1%, p = 0.006). Fluorescein rise time was prolonged in patients with neuropathy compared with the control group (48.5 +/- 7.0 s vs 14.0 +/- 3.1 s, p = 0.001) suggesting impaired nerve blood flow. There was a correlation between rise time, nerve oxygen saturation, glycaemic control and sural nerve sensory conduction velocity (p < 0.01).

CONCLUSION/INTERPRETATION

The combination of microlight-guide spectrophotometry and micro-endoscopy provides a valuable minimally invasive technique for clinical investigation of nerve microcirculation. We have shown reduced nerve oxygenation and impaired blood flow in diabetic neuropathy and these findings strongly support a central role of microvascular disease in the pathogenesis of diabetic neuropathy.

Unsuspected bile duct paucity in donors for living-related liver transplantation: two case reports

Alagille's syndrome is a common cause of liver disease in children and may lead to the need for orthotopic liver transplantation. Alagille's syndrome is inherited in an autosomal dominant manner, with variable penetration, and may also be present in patients' parents, who may be considered potential donors for living-related transplantation. We report here on two cases in which the living-related donors for children with Alagille's syndrome had no liver function abnormalities or characteristic features of Alagille's syndrome. In both cases, the operation for living-related donation had to be aborted because of a paucity of bile ducts discovered intraoperatively. Given the variable presentation of Alagille's syndrome, we believe that it is necessary preoperatively to evaluate the biliary system of family members who are potential living-related donors for patients with this condition.

Radiotherapy for unilesional mycosis fungoides

PURPOSE

To evaluate the treatment outcome and natural history of patients with the diagnosis of unilesional mycosis fungoides, treated according to a prospective radiotherapy protocol in our institution since July 1975.

METHODS AND MATERIALS

A total of 325 patients with the diagnosis of mycosis fungoides have been referred to the Department of Radiation Oncology at Allegheny University of Health Sciences from July 1975 through September 1996. Of these, 18 patients (5%) were classified as having unilesional mycosis fungoides and were irradiated with a curative intent using local electron fields. One patient received 22 Gy; 1 patient received 40 Gy, and the rest of the patients 30.6 Gy. Daily fractions ranged from 1.8 to 2.0 Gy. Treatments prior to radiation consisted of topical steroids and/or antifungal creams in the majority of patients, with temporary partial responses. One patient had received 2 years of topical mechlorethamine (HN2) and another patient had received topical carmustine solution (BCNU) without response prior to irradiation.

RESULTS

The responses were measured clinically; posttreatment skin biopsy was not performed routinely unless there was clinical evidence of disease persistence. Complete response rate was 100%; all treated lesions cleared completely within 4 to 8 weeks after the completion of radiation. With a median follow-up of 43 months (range 12 to 240 months), 2 relapses have occurred, 2 and 71 months after the completion of radiation. Both relapses were confined to the skin and were remote from the original site. Both relapses responded to topical application of HN2. There have been no recurrences in the irradiated field nor systemic dissemination. No long-term side effects were found related to treatment, and all the patients are currently alive and without evidence of disease. Actuarial relapse-free and overall survival at 10 years are, respectively, 86.2% and 100%.

CONCLUSION

Unilesional mycosis fungoides has a long natural history, is possibly the earliest manifestation of a malignant process, and local treatments, including local radiotherapy, result in long-term disease-free intervals and, possibly, cure. Total skin electron beam radiotherapy is not indicated for this disease entity.

Complications in 100 living-liver donors

OBJECTIVE

A review of 100 living-liver donors was performed to evaluate the perisurgical complications of the procedure and thus to help quantify the risks to the donor.

SUMMARY BACKGROUND DATA

Despite the advantages of living-donor liver transplantation (LDLT), the procedure has received criticism for the risk it imposes on healthy persons. A paucity of data exists regarding the complications and relative safety of the procedure.

METHODS

One hundred LDLTs performed between November 1989 and November 1996 were reviewed. Donor data were obtained by chart review, anesthesia records, and the computerized hospital data base. Patient variables were compared by Fisher's exact test and the Student's t test.

RESULTS

There were 57 women and 43 men with a median age of 29. Donors were divided into two groups: group A (first 50 donors), and group B (last 50 donors). There were 91 left lateral segments and 9 left lobes. There were no deaths. Fourteen major complications occurred in 13 patients; 9 occurred in group A and 5 in group B. Biliary complications consisted of five bile duct injuries (group A = 4, group B = 1) and two cut edge bile leaks. Complications were more common in left lobe resections (55%) than in left lateral segment grafts (10%). Minor complications occurred in 20% of patients. A significant reduction in overall complications (major and minor) was observed between the groups (group A, n = 24 [45%] vs. group B, n = 10 [20%]). In addition, surgical time and hospital stay were both significantly reduced.

CONCLUSIONS

Although the procedure is safe, many LDLT donors have a perisurgical complication. Surgical experience and technical modifications have resulted in a significant reduction in these complications, however. To minimize the risks for these healthy donors, LDLT should be performed at institutions with extensive experience.

Radical Sphincter preservation surgery with coloanal anastomosis following high-dose external irradiation for the very low lying rectal cancer

High-dose preoperative radiation and specifically designed surgical techniques were used to extend the application of sphincter preservation surgery for cancer of the distal 3 cm of the true rectum. A total of 203 consecutive patients with rectal cancer were treated with external-beam irradiation (45-70 Gy) and radical curative surgery. The cancer was at the level of 0.5-3.0 cm in 65 patients. In these 65 patients treated by radical resection with coloanal anastomosis six suffered recurrence (9%), and the 5-year actuarial survival was 85%. There was a single death. There was no local recurrence among 44 patients in whom the postradiated cancer resided in the rectal wall with or without nodal involvement. With proper selection, high-dose preoperative radiation therapy thus permits extended use of sphincter preservation surgery with coloanal anastomosis for cancers of the distal 3 cm of the true rectum.

Use of barbiturates in the treatment of cyclic vomiting during childhood

BACKGROUND

Cyclic vomiting is an uncommon disorder that can be described as recurrent, self-limiting, fairly uniform episodes of intractable nausea and vomiting with no identifiable organic cause, separated by symptom-free intervals. There is no established therapeutic regimen for this disorder.

METHODS

Fourteen children referred to the Pediatric Gastroenterology Clinic were diagnosed with cyclic vomiting from May 1984 to January 1995. Vomiting, the predominant symptom, was present in all children and was severe enough to require hospitalization in 11. Associated symptoms included abdominal ain, headache, nausea, aura, and fever. Diagnostic studies were done to rule out organic causes as indicated in individual patients. Daily phenobarbital was prescribed in all 14 patients. The dose ranged from 30 to 120 mg/hs, (mean 2 mg.kg-1.day-1), with a median dose of 60 mg/hs [corrected]. Prior therapy with propranolol (3 patients) and butalbital (2 patients) had been ineffective.

RESULTS

Eleven patients had complete resolution of their symptoms, and 3 patients had marked improvement in their symptoms with infrequent attacks of reduced severity. The only side effects associated with long-term phenobarbital therapy were behavioral in nature, namely hyperactivity and disruptive behavior at school.

CONCLUSIONS

The results of our series of 14 patients, all of whom received barbiturates, support the usefulness of this therapeutic approach. Hence we feel that daily low-dose phenobarbital therapy is a safe and effective therapy in preventing episodes of cyclic vomiting in children.

HIV integrase: a target for AIDS therapeutics

HIV integrase catalyses the incorporation of virally derived DNA into the human genome. This unique step in the virus life cycle provides a variety of points for intervention and hence is an attractive target for the development of new therapeutics for the treatment of AIDS. In this review we summarize current knowledge of the function of this enzyme and discuss some of the obstacles to the development of appropriate drugs.

The acute phase response to cardiopulmonary bypass in children

The endocrine phase of the stress response to cardiopulmonary bypass in children is known to be subtly different from that seen in adults. The aim of this investigation was to determine whether there are similar differences in the acute phase response. Thirteen children were studied (mean age 2.65 years). Each child had congenital heart disease and underwent corrective cardiac surgery. Blood samples taken two days prior to operation and at 6, 9, 12, 24, 48 and 120 hours after were analysed for C-reactive protein, albumin, caeruloplasmin, zinc and copper concentrations. Metal:carrier protein molar ratios were also calculated. Results demonstrate changes which, although similar to those seen in adults, differed both quantitatively and qualitatively. This is explained by the concept of immaturity leading to a generally poor capacity for protein synthesis and a relative inability to respond to altered circumstances.

Distribution of hippocampal mineralocorticoid and glucocorticoid receptor mRNA in a glucocorticoid resistant nonhuman primate

Glucocorticoids regulate the activity of the hypothalamic-pituitary-adrenal axis through both mineralocorticoid (MR) and glucocorticoid (GR) receptors in the hippocampus. In addition, glucocorticoids down-regulate hippocampal expression of MR and GR mRNA and protein, presumably decreasing their own effect. Marmosets are a New World primate characterized by extraordinarily high levels of circulating ACTH and cortisol. The relative glucocorticoid insensitivity of these animals to their massive levels of glucocorticoids was attributed to a decreased affinity of their GR for glucocorticoids, as well as a compromised ability of this receptor to transactivate glucocorticoid-responsive genes. The lack of mineralocorticoid excess, on the other hand, was attributed to a renal MR which responded poorly to cortisol, but normally to aldosterone. The purpose of this study was to examine MR and GR mRNA expression in the marmoset (Callithrix jacchus jacchus) hippocampus. Overall, steady state levels of both MR and GR mRNA were elevated in all of the hippocampal subfields of the marmoset, and this was obvious in rough comparisons with those of a typical glucocorticoid-sensitive Old World primate, the rhesus monkey (Macaca mulata). Notable were the extremely high levels of GR mRNA in the dentate gyrus and field CA3 of the marmoset. The GR mRNA density distribution of the marmoset also appeared to differ from that in the rhesus and from those previously reported in rats and humans. These findings suggest that there is a compensatory elevation of MR and GR mRNAs in the marmoset hippocampus, which appears to be the result of target tissue resistance to glucocorticoids and inappropriate down-regulation by the elevated, but ineffective, circulating cortisol.

Dialysis access via a right ventricular assist device

In this report, we describe the successful utilization of an external right ventricular assist device as vascular access for hemodialysis and continuous arteriovenous hemodialysis in a critically ill patient on biventricular mechanical assist support. Utilization of the right ventricular assist device lines provided relatively easy and safe dialysis access and temporarily reduced the risks associated with the conventional vascular access techniques.

Regression of retinoblastoma after plaque radiotherapy

A review of 400 consecutive patients with retinoblastoma disclosed that 103 tumors in 103 eyes were treated with solitary plaque radiotherapy. The tumors were from 1 to 16 mm (mean, 7 mm) in basal diameter and from 1 to 8 mm (mean, 4 mm) in thickness. Thirty-one tumors were treated with plaque radiotherapy as initial treatment, whereas 72 tumors were treated with plaque radiotherapy as secondary treatment after failure of other methods. Of the 102 tumors on which adequate follow-up data were available, all responded initially to plaque radiotherapy with tumor regression. Over the mean follow-up of 38 months (range, six to 192 months), 89 tumors (87%) showed persistent regression and 13 (13%) showed tumor recurrence. The recurrence occurred at a mean interval of five months (range, one to 11 months) after plaque radiotherapy. A statistical analysis of tumor size, tumor location, tumor proximity to the optic disk and foveola, presence of vitreous seeds, radioactive plaque diameter, plaque shape, radioisotope, and primary or secondary treatment disclosed no important predictors of tumor recurrence. Carefully selected retinoblastoma, even juxtapapillary and macular tumors and those with localized vitreous seeds, can be successfully treated with plaque radiotherapy.

Immunoquantitation of carnitine palmitoyl transferase in skeletal muscle of 31 patients

We studied 31 patients suspected of having muscle carnitine palmitoyl transferase 2 (CPT2) deficiency. The catalytic activity of CPT2 was measured in muscle biopsies by the isotope exchange method and CPT2 immunoreactivity was quantitated by an enzyme-linked immunosorbent assay. Nine patients had normal enzyme activity and immunoreactivity. Eight patients had significant deficiencies in catalytic activity (> 3 S.D. below reference mean) of which six were also deficient in immunoreactivity. An additional nine patients were significantly deficient in immunoreactivity with normal catalytic activity and five patients had partial deficiencies in both. At least two categories of alterations in CPT may exist which lead to a deficiency based on the data presented: (1) a regulatory defect in CPT which only alters the enzyme active site; and (2) a structural defect due to altered synthesis, increased degradation, or changes in the immunoreactive site. It may prove to be of diagnostic importance to combine the analysis of enzyme activity and immunoreactivity in patients suspected of having a CPT deficiency and to further investigate the condition of partial CPT deficiency.

Structure and molecular model refinement of Aspergillus oryzae (TAKA) alpha-amylase: an application of the simulated-annealing method

Monoclinic crystals of a neutral alpha-amylase from Aspergillus oryzae, containing three molecules in the asymmetric unit, have been reported previously and studied at 3 A resolution [Matsuura, Kunusoki, Harada & Kakudo (1984). J. Biochem. 95, 697-702]. Here we report the solution of the structure of this enzyme in a different crystal form (space group P2(1)2(1)2(1), a = 50.9, b = 67.2, c = 132.7 A), with only one molecule in the asymmetric unit. The structure was solved by the molecular replacement method, using a model of acid alpha-amylase from a related fungus A. niger [Brady, Brzozowski, Derewenda, Dodson & Dodson (1991). Acta Cryst. B47, 527-535]. Conventional least-squares crystallographic refinement failed to converge in a satisfactory manner, and the technique of molecular dynamics in the form of the XPLOR package [Brunger (1988). XPLOR Manual. Yale Univ., USA] was used to overcome the problem. A large rigid-body type movement of the C-terminal domain was identified and accounted for. The final round of restrained least-squares refinement (at 2.1 A resolution) including 3675 protein atoms and 247 water molecules resulted in a conventional crystallographic R factor of 0.183 and an atomic model which conforms well to standard stereochemical parameters (standard deviation of bond lengths from their expected values is 0.028 A, while that for planar groups is 0.029 A).

Calcium binding in alpha-amylases: an X-ray diffraction study at 2.1-A resolution of two enzymes from Aspergillus

X-ray diffraction analysis (at 2.1-A resolution) of an acid alpha-amylase from Aspergillus niger allowed a detailed description of the stereochemistry of the calcium-binding sites. The primary site (which is essential in maintaining proper folding around the active site) contains a tightly bound Ca2+ with an unusually high number of eight ligands (O delta 1 and O delta 2 of Asp175, O delta of Asn121, main-chain carbonyl oxygens of Glu162 and Glu210, and three water molecules). A secondary binding site was identified at the bottom of the substrate binding cleft; it involves the residues presumed to play a catalytic role (Asp206 and Glu230). This explains the inhibitory effect of calcium observed at higher concentrations. Neutral Aspergillus oryzae (TAKA) alpha-amylase was also refined in a new crystal at 2.1-A resolution. The structure of this homologous (over 80%) enzyme and additional kinetic studies support all the structural conclusions regarding both calcium-binding sites.

The radiation therapy of early stage cutaneous T-cell lymphoma

Results of different radiotherapy schedules used for early stage (T1-2, N0-1, M0) cutaneous T-cell lymphoma (CTCL) are compared in a series of 45 patients (22 patients treated with high dose total skin electron beam therapy (TSEB) with curative intent, 18 patients treated with palliative radiotherapy, and 5 patients treated with high dose local electron beam). At 3, 5, and 10 years after diagnosis the high dose TSEB treatment group had a probability of overall survival of 91%, 86%, and 75%, respectively, compared with 94%, 88%, and 88% for the palliative treatment group. The complete response (CR) rate for the high dose TSEB treatment group was 82% (18/22), compared with a 57% (4/7) complete response rate for seven patients in the palliative group who received low dose TSEB (less than 25 Gy in 6-7 weeks) followed by daily application of topical mechlorethamine hydrochloride (HN2). However, the probability of continued remission at 3, 5, and 10 years was 44%, 44%, and 33%, respectively, for the high dose TSEB group and 25%, 25%, and 0%, respectively, for the low dose TSEB + HN2 group. The median disease-free survival was 17.5 months for the high dose TSEB group versus 5.5 months for the low dose TSEB + HN2 group. The five patients who were treated with high doses of local electrons to a single local field had an overall survival rate of 80%, a median survival rate of 64 months, and a median length of continued remission of 31 months. These results indicate that high-dose electron beam can result in long-term disease-free survival in patients with localized and limited extent skin involvement with cutaneous T-cell lymphoma.

A serine protease triad forms the catalytic centre of a triacylglycerol lipase

True lipases attach triacylglycerols and act at an oil-water interface; they constitute a ubiquitous group of enzymes catalysing a wide variety of reactions, many with industrial potential. But so far the three-dimensional structure has not been reported for any lipase. Here we report the X-ray structure of the Mucor miehei triglyceride lipase and describe the atomic model obtained at 3.1 A resolution and refined to 1.9 A resolution. It reveals a Ser..His..Asp trypsin-like catalytic triad with an active serine buried under a short helical fragment of a long surface loop.

Effects of serotonergic agonists and antagonists on corticotropin-releasing hormone secretion by explanted rat hypothalami

Experimental evidence suggests that serotonin (5HT) is excitatory to the hypothalamic-pituitary-adrenal axis and that this effect involves activation of both hypothalamic corticotropin-releasing hormone (CRH) and pituitary ACTH secretion. The present study was undertaken to examine the mechanism by which 5HT stimulates the central component of the HPA axis. To accomplish this we employed an in vitro rat hypothalamic organ culture system in which CRH secretion from single explanted hypothalami was measured by specific radioimmunoassay (IR-rCRH). All experiments were performed after an overnight (15-18 hr) preincubation. Serotonin stimulated IR-rCRH secretion in a dose-dependent fashion. The response was bell-shaped and the peak effect was observed at the concentration of 10(-9) M. The stimulatory effect of 10(-9) M 5HT was antagonized by the 5HT1 and 5HT2 receptor metergoline and by the selective 5HT2 receptor antagonists ketanserin and ritanserin. The muscarinic antagonist atropine, the nicotinic antagonist hexamethonium and the alpha-adrenergic receptor antagonist phentolamine, on the other hand, did not inhibit 5HT-induced IR-rCRH secretion. The specific 5HT2 receptor agonist 1-(2,5-dimethoxy-4-iodo-phenyl)-2-aminopropane (DOI) stimulated IR-rCRH secretion in a dose-dependent fashion. The response was bell-shaped with peak of effect reached at the concentration of 10(-9) M. We also tested the ability of the 5HT agonist meta-chlorophenylpiperazine (m-CPP) and of the selective 5HT1A receptor agonist 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) to cause CRH secretion. Although both m-CPP and 8-OH-DPAT stimulated IR-rCRH secretion in a dose-dependent fashion, several differences were observed when their effect was compared to that of 5HT. These included a different shape of the dose-response curve, a lower maximal stimulatory effect and a different maximal stimulatory concentration. These findings suggest that serotonin stimulates CRH secretion by explanted rat hypothalami and that this effect appears to be mediated mainly through a 5HT2 receptor mechanism.

Motor and sensory abilities with normal and academically at-risk children

Motor and sensory abilities were assessed with children identified as normal and children identified as academically at-risk. The children were grouped based on the results of a screening procedure which consisted of tasks designed to assess academic readiness skills. The results indicated that the academically at-risk children did significantly poorer on most of the measures of motor and sensory functioning. Discriminant analyses indicated that the measures were generally more effective at classifying the normal children than the academically at-risk children. The results are discussed in relation to developmental models of neuropsychological functioning.

Campylobacter pyloridis gastritis II: Distribution of bacteria and associated inflammation in the gastroduodenal environment

The distribution of Campylobacter pyloridis in the stomach and duodenal bulb of two series of patients (n = 53) with dyspeptic symptoms was studied. In all patients where a comprehensive search of the stomach was conducted, C. pyloridis and active chronic gastritis were associated. That is, the presence of this organism anywhere in the stomach may be taken as a marker of active chronic gastritis within that stomach, although not necessarily at the site of bacterial detection. Two main patterns of colonization are proposed: C. pyloridis either colonizes normal antra and extends proximally along the lesser curvature and into the body with subsequent development of active chronic gastritis and/or the bacterium colonizes areas of chronic-only gastritis induced by other agents resulting in active chronic gastritis. As C. pyloridis may be limited to the antrum or body of any given stomach, it is necessary to biopsy both areas when looking for the bacterium.

Campylobacter pyloridis and gastritis: association with intercellular spaces and adaptation to an environment of mucus as important factors in colonization of the gastric epithelium

Stomach biopsy specimens from greater than 40 individuals with Campylobacter pyloridis-associated gastritis were examined by light and electron microscopy. The bacteria were consistently seen in two locations: within the gastric mucus and associated with intercellular junctions of gastric epithelial cells. C. pyloridis is suggested to be one of a broad group of spiral bacteria that are adapted to the peculiar niche provided by intestinal mucus. The spiral morphology and the form of motility of these organisms give them a selective advantage in a viscous environment. This point has been demonstrated in vitro by measurement of the velocity of clinical isolates in solutions of methyl cellulose of varying viscosity. The localization of C. pyloridis close to intercellular junctions is proposed to be due to the presence of preferred metabolites or growth factors, e.g., urea and hemin. All isolates show an extremely high urease activity and require hemin for growth.

Psychological, nutritional and physical status of olympic road cyclists

Six members of the Irish Olympic Road Cycling Squad underwent a comprehensive medical, nutritional, psychological and biochemical assessment in January 1983. They were given specific medical and dietary recommendations and were reassessed in January 1984 after a period spanning the competitive racing season. The cyclists' diets at both sessions were comparable and generally conformed with recommended daily intakes. Supplementary ingestion was unnecessary to attain recommended daily intakes of vitamins. Serum levels of HDL-cholesterol increased and triglyceride decreased during the period of the study. The squad had characteristics indicating traits of self-sufficiency, toughness and practical mindedness. At the second assessment there was evidence of heightened ambition and competitiveness and an improvement in mood states with reduced ratings for confusion and tension.

Antibiotic-resistant staphylococci in a teaching hospital

A large, continuing outbreak of infection and colonisation with a Staphylococcus aureus which is resistant to methicillin and gentamicin is reported. Affected patients and staff members seen between September, 1980, and August, 1981, are reviewed in detail. Methods of management of such persons and their treatment, if required, are discussed. The antibiotic-resistant Staph. aureus is readily disseminated in hospitals and may cause outbreaks of infection in wards, which require isolation of affected patients in the attempt to control the problem. It is suggested that a special isolation unit is needed. Use of the few effective antibiotic agents should be restricted. Despite these measures, the spread of this organism may not be contained.