Time of the day for 11beta-HSD1 inhibition plays a role in improving glucose homeostasis in DIO mice.

AIMS: The physiological effects of glucocorticoids in a given tissue are driven by the local level of the active glucocorticoid, which is determined by two sources: the plasma cortisol in human (or corticosterone in rodents) and the cortisol produced locally through 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) activity. Because of the circadian variation of plasma glucocorticoids, the pharmacological efficacy of 11beta-HSD1 inhibition may depend on the time of the day for inhibitor administration. METHODS: The circadian profile of corticosterone was established in lean and diet-induced obesity (DIO) C57BL/6 mice from blood collected at different time of the day. 11beta-HSD1 enzyme activity was also measured throughout the day in DIO mice. To determine the optimal timing for administration of an 11beta-HSD1 inhibitor to obtain maximum efficacy, we used a DIO mouse model and a small molecule inhibitor of 11beta-HSD1 from our thiazolinone series. Based on the circadian profile of corticosterone obtained, we administered the 11beta-HSD1 inhibitor to these animals at different times of the day and evaluated the effects on plasma glucose levels and glucose tolerance. RESULTS: We report that corticosterone circadian rhythm was similar between lean and DIO C57BL/6 mice, and 11beta-HSD1 enzyme activity undergoes minimal variations throughout the day. Interestingly, the compound exhibited maximum efficacy if dosed in the afternoon when plasma corticosterone is high; the morning dosing when plasma corticosterone is low did not lead to efficacy. CONCLUSION: These data suggest that because of the circadian rhythm of circulating glucocorticoids, the time of the day for 11beta-HSD1 inhibitor administration is important in achieving efficacy.

Photoremodeling of arterial wall reduces restenosis after balloon angioplasty in an atherosclerotic rabbit model.

OBJECTIVES: This study evaluated the long-term impact of endoluminal low power red laser light (LPRLL) on restenosis in an atherosclerotic rabbit model. BACKGROUND: Despite widespread application of balloon angioplasty for treatment of coronary artery disease, restenosis limits its clinical benefits. Restenosis is a complex process and may be partly attributed to the inability of the vascular endothelium to regenerate and cover the denuded area at the site of arterial injury. We previously demonstrated that LPRLL stimulates endothelial cell proliferation in vitro and contributes to rapid endothelial regeneration after balloon injury in nonatherosclerotic rabbits. METHODS: Rabbit abdominal aortas (n = 12) were treated in separate zones with balloon dilation and balloon dilation plus laser illumination. Endoluminal laser therapy was performed using a laser-balloon catheter delivering a single dose of 10 mW for 3 min from a helium-neon laser (632 nm). Angiography was performed before and after treatment and was repeated 8 weeks before harvesting the aortas. RESULTS: Quantitative angiographic analysis demonstrated no differences in the minimal lumen diameter (MLD) between the two zones before treatment; an increase in the MLD in both zones after balloon angioplasty and a significant versus slight reduction of the MLD in the balloon treatment versus balloon plus laser zones at 8 weeks. Histologic examination showed a very high level of myointimal hyperplasia in the balloon treatment zones but a minimal level in the LPRLL-treated zones. Morphometric analysis revealed a statistically significant difference in the lumen area, intimal area and intima/media ratio between the balloon versus balloon plus laser treatment sites. CONCLUSIONS: Our experimental data indicate that endoluminal irradiation with LPRLL prevents restenosis after balloon angioplasty in an atherosclerotic rabbit model.

Endoluminal reconstruction of the arterial wall with endothelial cell/glue matrix reduces restenosis in an atherosclerotic rabbit.

OBJECTIVES: The objectives of this study were 1) to improve the attachment of reimplanted endothelial cells (EC) using a fibrin glue, and 2) to assess the impact of endothelial reseeding on restenosis eight weeks after balloon angioplasty. BACKGROUND: A possible mechanism contributing to restenosis after balloon angioplasty is the loss of the EC lining. Previous attempts to reseed EC had little effect due to rapid loss of the seeded cells. METHODS: Twelve atherosclerotic rabbits were subjected to angioplasty of iliac arteries and reseeding procedure. One iliac artery was subjected to EC/glue reconstruction and a contralateral site to EC seeding without glue. The animals were sacrificed after 4 h. In another series 12 rabbits were treated in the same fashion and were restudied at eight weeks. Additionally, in 10 animals one iliac was subjected to glue treatment, and another served as control. RESULTS: Histological examination demonstrated the ability of this method to reattach the EC/glue matrix circumferentially to 68.0 +/- 6.7% of the arterial wall in comparison with 13.5 +/- 3.9% reattachment after EC seeding. Morphometry at eight weeks showed that the lumen area was significantly greater in the EC/glue group (1.23 +/- 0.35 mm2) than in the EC seeding alone (0.65 +/- 0.02 mm2) and 0.72 +/- 0.41 mm2 in the glue group. This was principally accounted for by the statistically significant differences in the intimal area (0.76 +/- 0.18 mm vs. 1.25 +/-0.26 mm2 and 1.01 +/- 0.53 mm2, respectively). CONCLUSIONS: The attachment of EC after angioplasty can be greatly improved with fibrin glue matrix. The near 70% endothelial coverage achieved by this method resulted in a significant reduction of restenosis in atherosclerotic rabbit.

Quantitative ultrasonic assessment of normal and ischaemic myocardium with an acoustic microscope: relationship to integrated backscatter.

PURPOSE OF INVESTIGATION: The aim was to study ultrasonic propagation properties of normal and ischaemic myocardium with a scanning laser acoustic microscope and to correlate these changes with ultrasonic backscatter. DESIGN: Myocardial ischaemia was produced by total occlusion of left anterior descending coronary artery in anaesthetised open chest dogs. Myocardium supplied by left circumflex coronary artery served as normal control. IBR5, an optimum weighted frequency average (4-6.8 MHz) of the squared envelope of diffraction corrected backscatter, was measured in vivo. Ultrasonic attenuation coefficient, an index of loss per unit distance, the propagation speed and heterogeneity index were measured from normal and ischaemic regions with a scanning laser acoustic microscope which operates at 100MHz in vitro. Myocardial water content of normal and ischaemic myocardium was also estimated. SUBJECTS: Were five anaesthetised mongrel dogs. RESULTS: Attenuation coefficient of 33.8(SD4.2) dB.mm-1 in the ischaemic tissue was lower than 63.8(17.2) dB.mm-1 in the normal tissue (p less than 0.01). Ultrasonic speed was lower in ischaemic than normal myocardium at 1584(25) v 1612(35) m.s-1 (p less than 0.05). Heterogeneity index of 11(7) m.s-1 in the ischaemic region was lower than 14(8) m.s-1 in the normal region (27% reduction, p less than 0.05). IBR5 and myocardial water content were higher in the ischaemic than the normal myocardium: -37.2(SEM1.8) dB v -46.6(0.6) dB, (p less than 0.01) and 80.9(0.0)% v 78(0.2)%, (p less than 0.05) respectively. CONCLUSION: Ultrasonic properties of the myocardium are significantly altered during acute ischaemia.

Gonococcal endocarditis associated with immune complex glomerulonephritis.

A case is described in which chronic gonococcemia probably resulted in endocarditis, nephrotic syndrome and diffuse immune-complex glomerulonephritis. This is the 11th case of gonococcal endocarditis reported since 1948 and the first report with accompanying immunofluorescence and electron microscopy of the kidney. These studies revealed immune-complex nephritis to be the likely cause of the patient's deteriorating renal function.

Histologic spectrum of diversion colitis.

Biopsy specimens taken from six patients with diversion colitis, an inflammatory process that occurs in the bypassed colonic segment after diversion of the fecal stream, showed a spectrum of histologic changes ranging from mild colitis to those seen in severe active chronic ulcerative colitis. Histologic abnormalities included aphthous ulcers, crypt distortion, atrophy and abscesses, a villous colonic surface, and a mixed acute and chronic inflammatory infiltrate with patchy lymphoid hyperplasia. Accurate pathologic diagnosis is dependent on clinical history, comparison of histologic morphology in both colonic segments, and response to therapy with local application of short chain fatty acids.

Hyperplastic gastropathy. Clinicopathologic correlation.

Assessment of gastric histology in patients with hyperplastic gastritis is now possible using new endoscopic biopsy techniques that obtain a full-thickness gastric mucosal biopsy. Thirty-one patients with hyperplastic gastropathy and full-thickness gastric mucosal biopsies or gastric resections were seen during a 13-year period. Six patients had Zollinger-Ellison syndrome (ZE) with gastric gland hyperplasia; six had Menetrier's disease with foveolar hyperplasia and gland atrophy; and a single patient with hyperplastic hypersecretory gastropathy (HHG) was seen. The majority of patients, 18 of 31 with large folds, had peptic disease. The enlarged gastric folds were due to edema and inflammation. Discordant clinical findings and gastric pathology were seen in four patients: three of the 18 patients with peptic disease had histology typical of ZE (two patients) or Menetrier's disease. None of the three patients have developed a syndrome on follow-up ranging up to 5 years. Also, the patient with HHG had the gastric histology seen in Menetrier's disease. One patient with Menetrier's disease had areas of atrophic gastritis interspersed between the hyperplastic gastritis. In summary, the majority of patients with endoscopic hyperplastic gastropathy had gastritis on histologic examination. Most patients with a clinical syndrome associated with hyperplastic gastritis showed histology typical for the syndrome; however, clinical-histologic concordance was not absolute. In a small minority of cases, a patient with one clinical syndrome had the histology typical of another.

Assessment of ampulla of Vater pathology. An endoscopic approach.

One hundred eighty-nine endoscopic biopsies of the papilla of Vater were obtained from 125 patients during a 10-year period. Chronic inflammation was the most common histologic change identified. Of the 44 patients with papillary neoplasia, 42 were diagnosed by endoscopic biopsy. Sixteen of the 18 patients with invasive carcinoma were diagnosed by biopsy. Follow-up biopsies in patients endoscopically managed demonstrated recurrent tumors in 6 of 11 patients. With advances in instrumentation and techniques, pathologists can expect to see increasing numbers of ampullary biopsies. When multiple biopsy fragments are obtained and step sectioned, the diagnostic reliability of endoscopic biopsies in patients with tumors and carcinoma is greater than 90%. The morphologic spectrum of papillary lesions is similar to that seen in the colon with some significant exceptions. Tumor morphology varied considerably from area to area. Variations were seen in the basic architecture (villous-tubular), grade of dysplasia, presence of malignancy, and invasion from fragment to fragment, and in some cases from microscopic field to field. Another notable difference between the ampulla and colon is the rich mucosal lymphatic network of the ampullary region. Thus, any carcinoma invading the lamina propria was diagnosed as invasive carcinoma.

Evaluation of micrometastases in sentinel lymph nodes of cutaneous melanoma: higher diagnostic accuracy with Melan-A and MART-1 compared with S-100 protein and HMB-45.

Accurate diagnosis of micrometastases in sentinel lymph nodes of cutaneous melanoma is critical for proper clinical management. S-100 protein and HMB-45 are the traditional immunomarkers widely used for this purpose. However, the interpretation of micrometastases by these markers is difficult with significant reduction in the diagnostic accuracy. S-100 protein demonstrates immunoreactivity for other nonmelanoma cells and obscures nuclear details, which are crucial for the interpretation of single cell metastases. We compared the new melanoma markers, Melan-A (clone A103) and MART-1 (clone M2-7C10), with S-100 protein and HMB-45, by examining 77 formalin-fixed paraffin-embedded sections of sentinel lymph nodes from 13 cases of primary cutaneous melanoma. CD68 (PG-M1) and hematoxylin-eosin-stained sections were also studied. Four pathologists interpreted the staining pattern after concealing the identity of each immunomarker. Az values (area under receiver operating characteristic curve) with receiver operating characteristic curve were higher with Melan-A (0.9742) and MART-1 (0.9779) compared with S-100 protein (0.8034) and HMB-45 (0.8651), demonstrating a higher diagnostic accuracy with Melan-A and MART-1 with superior detection of melanoma micrometastases. Melan-A and MART-1 showed sharp cytoplasmic immunoreactivity, almost exclusively restricted to the melanoma cells. Therefore, Melan-A and MART-1 are recommended for the evaluation of micrometastases in sentinel lymph nodes of cutaneous melanoma as a routine alternative to S-100 protein and HMB-45.

NOX 100, a nitric oxide scavenger, enhances cardiac allograft survival and promotes long-term graft acceptance.

BACKGROUND: We examined the role of nitrosative stress in allograft destruction. METHODS: Rats undergoing cardiac transplants received NOX-100, a water-soluble nitric oxide (NO) scavenger with antioxidant properties, with or without low-dose cyclosporine (CsA). Graft survival, NO production, and nuclear factor kappa B (NF-kappaB) activity were studied. RESULT: Using NOX-100 daily until rejection prolonged graft survival (11.6+/-0.6 vs. 7.4+/-0.2 days; P<0.05). Daily low-dose CsA (2.5 mg/kg im) for 7 days or until rejection also prolonged survival (12.6+/-0.5 and 21.6+/-1.6 days, respectively; P<0.01 vs. Controls). Low-dose CsA for 7 days and NOX-100 for 30 days prolonged graft survival (45.0+/-4.7 days; P<0.01 vs. all groups.). NOX-100 had no effect on whole blood CsA levels. Combination therapy until Day 100 resulted in 1 graft loss at Day 116 and indefinite survival in 3 animals (>300 days), which accepted a second WF strain heart without further immunosuppressive therapy but promptly rejected a third party (ACI) cardiac allograft. NOX-100 and CsA reduced nitrate and nitrite, and combination therapy completely normalized NO through to Day 30. Electron paramagnetic resonance spectroscopic analysis demonstrated reduction of signals for nitrosylmyoglobin and nitrosyl-heme with NOX-100 and elimination of signals with CsA alone or combination therapy. Activity of myocardial NF-kappaB decreased with monotherapy vs. untreated allografts. Combination therapy resulted in further inhibition of NF-kappaB up to Day 30. The extent of graft survival correlated with the extent of NO scavenging and NF-kappaB inhibition. Short-term combination therapy had no effect on graft lymphocytic infiltrate on Days 15, 20, and 30. CONCLUSION: These data support a role for both oxidative and nitrosative stress in rejection and the immunoregulatory potential of antioxidant therapy after transplantation.

Myocardial nuclear factor-kappaB activity and nitric oxide production in rejecting cardiac allografts.

BACKGROUND: Nuclear factor-kappaB (NF-kappaB) is a rapid response transcription factor for genes whose products are critical for inflammation and immunity. In a rat model of heterotopic cardiac transplantation, we studied NF-kappaB DNA binding activity and nitric oxide (.NO) production in untreated allografts and whether inhibition of NF-kappaB suppresses .NO production and prolongs graft survival. METHODS: In allograft recipients and isograft controls, NF-kappaB was assayed by electrophoretic mobility shift assay, daily from transplant until rejection. Myocardial .NO was directly detected in explanted allografts by electron spin resonance spectroscopy on day 6 after transplant. The potent inhibitor of NF-kappaB, pyrrolidine dithiocarbamate (PDTC; 250 mg/kg s.c.) was administered daily from transplant until day of rejection. The extent of graft lymphocytic infiltrate was assessed by routine hematoxylin and eosin staining. Immunohistochemical staining of NF-kappaB was per formed to identify the cell type responsible for NF-kappaB activity. RESULTS: A time-dependent increase in myocardial NF-kappaB activity was seen in untreated allografts as compared with isografts as determined by PhosphorImage analysis. Peak NF-kappaB activity occurred in allografts on day 4 with a ninefold increase as compared with isografts (24.0+/-3.7% vs. 2.7+/-0.5; P<0.05). On posttransplant day 6, electron spin resonance spectroscopy analysis of allografts demonstrated .NO identified by a triplet nitrogen signal centered at g=2.012 with hyperfine splitting of 17.5 Gauss, which is consistent with nitrosoheme formation and low-field signals at g=2.08 and g=2.03 consistent with nitrosomyoglobin. These signals were not seen in native hearts of allograft recipients. With PDTC administration, a threefold decrease in NF-kappaB activity within the transplanted heart was observed on posttransplant day 5 as compared with untreated allografts (9.7+/-1.6% vs. 23.5+/-2.5%; P<0.01). PDTC prolonged graft survival as compared with untreated allografts (11.7+/-0.3 vs. 6.6+/-0.2 days; P<0.05) and reduced the intensity of the nitrosoheme and nitrosomyoglobin signals. Allograft mononuclear cell infiltrate correlated with peak NF-kappaB activity with peak infiltrate on posttransplant day 4. PDTC treatment had no effect on the extent of infiltrate. Immunohistochemical staining localized NF-kappaB to the infiltrating mononuclear cells on posttransplant day 5. CONCLUSION: These data support a role for NF-kappaB in allograft rejection.

Severe bleeding diathesis associated with invasive aspergillosis in transplant patients.

A severe bleeding disorder developed in eight renal transplant patients with invasive aspergillosis. The hemorrhagic diathesis was characterized by wound oozing, severe upper and lower gastrointestinal tract hemorrhage, and mucosal bleeding at other sites. This unusual coagulopathy was characterized by a prolonged thrombin time, which was corrected with protamine sulfate, and an abnormal Reptilase time. The bleeding disorder antedated the diagnosis of invasive aspergillosis in all cases. The probability that the coagulopathy was due to proteolytic enzymes elaborated by Aspergillus sp. is discussed.

Occult thyroid pathology in the young adult: an autopsy study of 138 patients without clinical thyroid disease.

Thyroid glands from autopsies on 138 adults, ages 20 to 40 years, with no known clinical or laboratory evidence of thyroid disease, were serially sectioned at 2 mm intervals and microscopically examined for occult thyroid disease and anatomic variations. Occult papillary carcinoma was found in 3% of the glands, along with a single case of medullary carcinoma. The prevalence of occult thyroid carcinoma in this group of young adults is significantly less than that reported in the literature in people over forty (P less than .001). The glands demonstrated a number of other morphologic changes of importance to surgical pathologists. The thyroid capsule was incomplete in 62% of the glands. Thyroid follicles were found in the capsule in 14% of cases and thyroid follicles or nodules were outside the gland in perithyroid connective tissue in 88% of cases. Thyroid follicles were identified in 7% of cases in perithyroid strap muscles attached to the pyramidal lobe. A number of other, less common anatomic variations were also seen.

Thyroglossal duct carcinoma.

Primary carcinoma of the thyroglossal duct is rare. This discussion reports two cases and reviews the 50 previously reported in the literature. The criteria for diagnosis include evidence of a thyroglossal duct remnant and a normal thyroid gland. The differentiation from cystic metastases to lymph nodes is pointed out. The histologic types parallel those of carcinoma of the thyroid gland, papillary carcinoma being the most common and having a generally favorable prognosis. The clinical presentation of these tumors is similar to that with benign cysts and thus is of limited value in the diagnosis.

Bronchiolitis obliterans organizing pneumonia in common variable immunodeficiency syndrome.

A 26-year-old woman with common variable immunodeficiency syndrome (CVID) associated with frequent episodes of pneumonia underwent an open lung biopsy showing bronchiolitis obliterans organizing pneumonia (BOOP). Following corticosteroid therapy, there were no further episodes of pneumonia. In addition, there was roentgenographic and gas exchange improvement. This is the first case of BOOP in association with CVID. An immunologic basis of BOOP is postulated.

Bronchiolitis obliterans. A new clinical-pathologic complication of irradiation pneumonitis.

A patient underwent chest irradiation for small-cell carcinoma of the left lung. Several weeks following cessation of irradiation, the patient developed hypoxemia and reticulonodular densities within the radiation port. Open lung biopsy yielded a pathologic diagnosis consistent with irradiation pneumonitis along with a previously unreported association, bronchiolitis obliterans. Bronchiolitis obliterans should be included in the pathologic description of irradiation pneumonitis.

Cardiac tamponade secondary to giant lymph node hyperplasia (Castleman's disease)

A unique association of giant lymph node hyperplasia (Castleman's disease) and cardiac tamponade is presented. Although pleural effusions have been previously described with Castleman's disease, the authors believe this to be the first report of pericardial effusion and tamponade with this entity. The development of effusions may be due to an inflammatory syndrome sometimes seen with the plasma cell variant of this disease.

Reversibility of cardiac xenograft rejection in primates.

More than 500 people died in 1988 because of the shortage of human heart donors. Cardiac xenografts from concordant primates may help to relieve this shortage. Two groups of ABO-matched cynomolgus monkey-to-baboon heterotopic cardiac xenografts were studied. Group 1 (n = 4) control animals had no immunosuppression. Group 2 (n = 6) baboons received cyclosporine, azathioprine, and methylprednisolone acetate. Myocardial biopsy, mixed lymphocyte culture, donor-specific crossmatch, and panel-reactive antibody determinations were performed after transplantation. Biopsy-proven rejection episodes (myocyte necrosis) were treated intravenously with steroids. A follow-up biopsy was performed 7 days after the first biopsy. If rejection persisted, antithymocyte globulin (10 mg/kg/day) was given for 7 days, and another biopsy was performed. Group 1 (control) graft survival was 8, 9, 9, and 10 days (mean, 9 days). Group 2 (immunosuppressed) graft survival was 3, 16, 18, 51, 84, and 392 days (mean, 94 days). Each immunosuppressed baboons' xenograft had myocyte necrosis and variable degrees of edema, cellular infiltrates, and vascular thrombosis consistent with mixed cellular and humoral rejection within 1 week. Only one rejection episode resolved with high-dose steroid therapy alone. Two baboons' rejection episodes resolved with antithymocyte globulin treatments, but rejection recurred in both. Low levels of or delayed progression of panel-reactive antibody was associated with long-term xenograft survival. Severe steroid-resistant rejection with cell-mediated and humoral immune elements developed early in our primate cardiac xenografts despite triple-drug immunosuppression. Use of antithymocyte globulin was associated with temporary resolution of rejection, but progressive increases in lymphocytotoxic antibody led invariably to eventual graft loss despite rare long-term survival.

Porokeratosis of mibelli in transplant recipients.

Four of 602 renal and hepatic transplant recipients had porokeratosis of Mibelli develop in the posttransplant period. Porokeratosis is an uncommon, autosomally dominant inherited disorder that presents in adolescence as a proliferation of an abnormal clone of epidermal cells. Clinically, it is characterized by nonhealing plaques that develop most commonly on the limbs. Porokeratosis, a premalignant condition, must be added to the list of potential cutaneous complications seen in immunosuppressed organ transplant recipients.

Cutaneous microabscess formation from Alernaria alternata.

A 69-year-old farmer with acute lymphocytic lymphoma developed multiple ulcerated hemorrhagic cutaneous lesions. Alternaria alternata was cultured from the lesions and hyphae were seen in biopsies of the lesions. The potential role of Alternaria as a human pathogen is discussed.