Guanosine enhances glutamate uptake and oxidation, preventing oxidative stress in mouse hippocampal slices submitted to high glutamate levels.

Glutamate (Glu) is the main mammalian brain neurotransmitter. Concerning the glutamatergic neurotransmission, excessive levels of glutamate in the synaptic cleft are extremally harmful. This phenomenon, named as excitotoxicity is involved in various acute and chronic brain diseases. Guanosine (GUO), an endogenous guanine nucleoside, possesses neuroprotective effects in several experimental models of glutamatergic excitotoxicity, an effect accompanied by an increase in astrocytic glutamate uptake. Therefore, the objective of this study was to investigate the involvement of an additional putative parameter, glutamate oxidation to CO2, involved in ex-vivo GUO neuroprotective effects in mouse hippocampal slices submitted to glutamatergic excitotoxicity. Mice were sacrificed by decapitation, the hippocampi were removed and sliced. The slices were incubated for various times and concentrations of Glu and GUO. First, the concentration of Glu that produced an increase in L-[14C(U)]-Glu oxidation to CO2 without cell injury was determined at different time points (between 0 and 90 min); 1000 µM Glu increased Glu oxidation between 30 and 60 min of incubation without cell injury. Under these conditions (Glu concentration and incubation time), 100 µM GUO increased Glu oxidation (35%). Additionally, 100 µM GUO increased L-[3,4-3H]-glutamate uptake (45%) in slices incubated with 1000 µM Glu (0-30 min). Furthermore, 1000  µM Glu increased reactive species levels, SOD activity, and decreased GPx activity, and GSH content after 30 and 60 min; 100 µM GUO prevented these effects. This is the first study demonstrating that GUO simultaneously promoted an increase in the uptake and utilization of Glu in excitotoxicity-like conditions preventing redox imbalance.

A semi-solid drug delivery system for epidermal growth factor in corneal epithelial wound healing.

PURPOSE: To examine the effects of EGF, delivered from a semi-solid drug delivery system, on corneal epithelial wound healing following anterior keratectomy wound creation in the eyes of New Zealand white rabbits. METHODS: A semi-solid drug delivery system based on a Carbopol gel was developed. Following creation of a 7.5 mm circular anterior keratectomy wound, 50 microL of either a placebo gel or an EGF-containing gel, was instilled in the inferior fornix. The gel remained in the eye for 8 hours, at which time it was removed. Anaesthesia was maintained for the entire 8-hour period. Wound healing was evaluated by quantitative morphometry. We evaluated 0.04, 0.1, 0.2, 0.4, and 1% EGF concentrations in the gel. Tear EGF concentrations and histology of the healing corneas were also examined. RESULTS: The enhancement factor (ratio of the healing rate with the EGF gel and control gel) was 1.13 +/- 0.12, 1.40 +/- 0.14, 1.29 +/- 0.12, 1.80 +/- 0.22, and 1.09 +/- 0.12 for the gels containing 0.04, 0.1, 0.2, 0.4, and 1% EGF by mass, respectively. The increases in the rate of wound healing were significant with the 0.1, 0.2 and 0.4% gel formulations. Histologically, the 0.4% gels resulted in cellular hyperplasia after 5 days of healing. Differences between the placebo gel-treated and EGF-containing gel-treated eyes were evaluated at both 2 and 5 days. The concentration of EGF in the tears during the treatment period was approximately constant for both the 1% and 0.04% gels. The average tear concentration during the instillation period was 2.87 +/- 0.36 micrograms/mL and 200.61 ng/mL +/- 116.10 for the 1% and 0.04% gels respectively. CONCLUSIONS: Treatment with EGF in a Carbopol gel carrier for a period of 8 hours results in significant wound healing enhancement (p < 0.05). The optimum EGF loading in the gel was determined to be 0.4%. A slow release gel may be an effective way to deliver EGF to the corneal surface.

Brief report: detection of high-molecular-weight cytokeratins in neoplastic and non-neoplastic thyroid tumors using microwave antigen retrieval.

Previous studies have demonstrated the utility of immunohistochemical staining for high-molecular-weight cytokeratins in the distinction of papillary carcinoma from other neoplasms of the thyroid, however, this technique was reliable only when applied to frozen tissues. Our objective in this study was to evaluate the use of this antibody in diagnostic thyroid pathology using paraffin-embedded materials with microwave antigen retrieval. We studied 89 thyroid tumors including 45 papillary carcinomas, 28 nodular hyperplasias, 10 follicular adenomas, and 6 follicular carcinomas. Moderate-to-strong diffuse staining was confined to papillary carcinoma, whereas follicular neoplasms and hyperplastic nodules were either negative or showed focal staining. These results confirm the utility of high-molecular-weight cytokeratins immunostaining in diagnostic thyroid pathology, and obviate the need for frozen material to apply this method. As paraffin-embedded tissues are more readily available, we recommend the use of high-molecular-weight cytokeratins with microwave antigen retrieval in cases in which it is difficult to distinguish papillary carcinoma from other thyroid tumors.

Papillary Hürthle cell carcinoma with lymphocytic stroma. "Warthin-like tumor" of the thyroid.

We report 13 cases of a peculiar thyroid tumor of follicular epithelial differentiation with distinctly papillary architecture, oxyphilic cytology, and lymphocytic infiltrates in papillary stalks. The majority of these tumors arose in glands with chronic lymphocytic thyroiditis. The combination of oxyphilic cells and lymphocytic stroma gives these tumors a startling resemblance to papillary cystadenoma lymphomatosum, or "Warthin's tumor" of the salivary gland. Twelve tumors occurred in women (age range: 26-66 years, mean 44 years). Two tumors were in the isthmus, six in the right lobe, and four in the left lobe. The only man, 34 years old, had multiple bilateral tumor nodules. The lesions ranged from 0.3 cm to 3.5 cm in maximum dimension. The largest lesion, in a 58-year-old woman, infiltrated skeletal muscle. Three other patients had lymph node metastases, while the nine remaining tumors were confined to the thyroid. Follow-up in these cases suggests that although the histological appearance of these neoplasms is unusual, they behave as typical papillary carcinomas. The striking lymphocytic infiltration and oxyphilic metaplasia in these tumors as well as the association with chronic lymphocytic thyroiditis suggest that as yet undefined immunological mechanisms may play a role in the pathogenesis of this disorder.

Clonality of thyroid nodules in sporadic goiter.

Clonality studies have suggested that neoplasms are monoclonal and hyperplasias are polyclonal. To investigate this question in thyroid, we analyzed the clonality of 26 morphologically characterized hyperplastic nodules from 19 patients with sporadic goiters. For comparison we studied six thyroid carcinomas. We used the highly informative M27 beta probe that maps to the X-chromosome DXS255 locus (X cen-p11.22). Material was obtained from 52 nodules; tissue from nine nodules was rejected because of contamination with normal elements, five patients (eight nodules) were homozygous at Pst I sites in nonnodular thyroid tissue, and three nodules were excluded for technical reasons. Methylation patterns after Hpa II digestion confirmed polyclonality in all nontumorous thyroids of informative patients. Seven hyperplastic nodules were polyclonal, and 18 were monoclonal; one showed loss of heterozygosity. One nodule exhibited aberrant methylation. Multiple nodules were obtained from four patients; in three, all were monoclonal with activation of the same allele. Three papillary carcinomas were monoclonal; two exhibited aberrant methylation. One follicular carcinoma showed loss of heterozygosity. Our data indicate that morphologically indistinguishable hyperplastic thyroid nodules may be monoclonal or polyclonal. These findings suggest that variable molecular mechanisms are involved in the pathogenesis of nodules in sporadic goiter. Future studies will need to explore the biological significance of nodules of variable clonal origin.

Malignant lymphoma presenting with an elevated serum CA-125 level.

An 80-year-old woman presented with fevers, night sweats, and weight loss. Her serum CA-125 level was markedly elevated (380 U/mL; normal < 35 U/ml). At post-mortem examination, the patient had widespread intermediate-grade malignant lymphoma with extensive infiltration of the greater omentum and pelvic peritoneum. Immunohistochemistry for CA-125 documented intense staining in the reactive mesothelial cells of the peritoneum; the tumor cells were not immunoreactive. CA-125 is a glycoprotein recognized by a monoclonal antibody raised against an ovarian-cancer cell line. Elevated levels have been reported rarely in patients with malignant lymphoma, and the pathophysiology of this finding has not been understood. Our data support the hypothesis that elevated CA-125 levels may reflect production by reactive mesothelium in patients with benign or malignant diseases involving the peritoneum, including malignant lymphoma. The clinical application of this marker, therefore, is broader than the recognized monitoring of patients with ovarian carcinoma.

Intrathyroidal lymphoepithelial cysts of probable branchial origin.

Lymphoepithelial cysts with histological features characteristic of branchial cleft cysts have been reported to occur rarely in the thyroid gland. To our knowledge only six cases of this lesion have been reported. Since these reports brought this entity to our attention, we have noted that intrathyroidal lymphoepithelial cysts are not rare lesions. We report six further cases; four were incidental histological findings, and two lesions were clinically detected masses. Each of the cysts had a squamous epithelial lining with abundant underlying lymphoid tissue, including lymphoid aggregates with large reactive germinal centers. All cases were associated with chronic lymphocytic thyroiditis. Because of the histological resemblance to branchial cleft cysts, it is postulated that these lymphoepithelial cysts are branchial in origin. The histogenesis of branchial cleft cysts is unknown; however, the ultimobranchial body, originating from branchial pouches four and/or five, contributes to the embryological development of the thyroid. Branchial cleft derivatives, such as thymus and parathyroid, develop in close association with the thyroid and may be found within the thyroid gland. These branchial cleft-like cysts also may arise from branchial cleft derivatives, and their enlargement may be related to the immunological mechanisms associated with autoimmune thyroiditis.

A metastasizing composite carcinoma of the thyroid with distinct medullary and papillary components.

Thyroid tumors with differentiation of both parafollicular and follicular epithelial cells are rare. The majority of those reported have been composed of a single cell population with combined features of the two cell types. We describe a 48-year-old man with a thyroid tumor composed of two discrete cell populations: thyroglobulin-positive papillary carcinoma intermixed with calcitonin-containing medullary carcinoma. The tumor metastasized to regional lymph nodes and maintained this composite differentiation. We propose that such tumors with two discrete intermingled cell populations be called composite thyroid carcinomas, as opposed to mixed thyroid tumors, which describes tumors with a single cell population that exhibits features of two cell types. Dual differentiation in thyroid neoplasms has been interpreted as indicative of a common stem cell origin. In this case, the presence of two mature, highly differentiated elements may suggest a proliferative response of two distinct cell populations to a common tumorigenic stimulus.

Prospective evaluation of early morphological changes in pelvic ileal pouches.

BACKGROUND/AIMS: Little is known about the evolution of morphological changes in pelvic ileal-pouch mucosa. This study evaluates prospectively the sequence of early morphological, histochemical, and phenotypic features in pouch mucosal biopsy specimens. METHODS: Twenty-two patients with pelvic ileal pouches constructed after total colectomy for chronic ulcerative colitis had biopsies performed at the time of ileostomy closure and after 6 weeks and 6 months of pouch function and were evaluated to assess the type and degree of inflammation, villus atrophy, Paneth's cell hyperplasia, mucin histochemical changes, the mucosal proliferative activity using the murine monoclonal antibody 1 (MIB-1), and the expression of the enzyme sucrase-isomaltase. RESULTS: Early changes (6 weeks) were characterized by neutrophilic and eosinophilic inflammation, mild villus atrophy, Paneth's cell hyperplasia, a partial transition to colonic mucin phenotype, and an increased MIB-1 proliferation index. These features remained relatively stable after 6 months, except for a greater degree of mononuclear infiltration, a progressive increase in the degree of eosinophilic inflammation and a new higher steady state level of crypt epithelial kinetics. Expression of sucrase-isomaltase remained stable. CONCLUSIONS: Pelvic ileal pouches develop inflammatory, phenotypic, and kinetic changes early in the course of function but have only a limited potential for colonic type metaplasia. The persistence of these changes is evidence in support of an adaptive response to a new luminal environment.

Continuous epidermal growth factor delivery in corneal epithelial wound healing.

PURPOSE: To investigate the effects of a single prolonged exposure to recombinant epidermal growth factor on the healing of anterior keratotomy wounds in New Zealand white rabbits. METHODS: After wounding, eyes were perfused for 1, 2, 4, and 8 hours with either epidermal growth factor solution at a concentration of 50 micrograms/ml or balanced saline solution using a Morgan therapeutic lens (Mortan Inc, Missoula MT) and a syringe pump. Furthermore, concentration response was evaluated by perfusing with epidermal growth factor solutions at concentrations of 5, 50, 100 and 500 micrograms/ml for 4 hours. Wound healing rates were determined by quantitative morphometry of the wound area. The ratio of healing rates of eyes perfused with epidermal growth factor and control eyes provided a measure of the effect of epidermal growth factor on wound healing, and was defined as the epidermal growth factor enhancement factor. RESULTS: The enhancement factor was found to be 1.04 +/- 0.08, 1.17 +/- 0.07, 1.43 +/- 0.09, and 1.59 +/- 0.07 for perfusion times of 1, 2, 4, and 8 hours, respectively. The concentration response enhancement factors were 0.99 +/- 0.08, 1.43 +/- 0.09, 1.21 +/- 0.09, and 0.95 +/- 0.07 for the 5, 50, 100, and 500 micrograms/ml 4-hour perfusions, respectively. CONCLUSION: The results indicated that continuous epidermal growth factor exposures of as few as 2 hours produced a significant increase in healing rates (P < 0.05); increasing the time of exposure further increases the rate of wound healing. Results from the concentration response experiments showed that the optimum epidermal growth factor concentration for enhancing epithelial wound healing is approximately 50 micrograms/ml.

Hepatitis B virus infection in liver allografts.

Liver transplantation of hepatitis B surface antigen (HBsAg)-positive patients has been associated with high morbidity and mortality secondary to hepatitis B (HB) recurrence in the graft. Eight patients of the Queensland Liver Transplant Service were HBsAg positive pretransplant. Six acquired HB infection of the graft, one developed serological recurrence of HB before early death from sepsis, and one HB e antigen-negative patient permanently cleared the virus. HB-infected grafts showed early expression of viral antigen, acute hepatitis, fibrosing cholestatic hepatitis, chronic active hepatitis, cirrhosis, or minimal changes associated with a carrier state. Only in the latter case was HB mild and nonprogressive. Cases of fibrosing cholestatic hepatitis progressed rapidly to liver failure; they showed fibrosis and plates of ductular epithelium extending from portal tracts into lobules, cholestasis, ballooning of hepatocytes, and prominent hepatocyte expression of viral antigens. Perioperative HB immunoglobulin proved ineffective in preventing HB recurrence. One other patient became HBsAg positive for the first time after retransplantation; he developed severe acute hepatitis, then chronic active hepatitis. Our biopsy findings support the view that, in liver allografts, the HB virus may be directly cytopathic.

Repair and reconstruction of the anterior cruciate ligament by the "Sandwich technique". A comparative microangiographic and histological study in the rabbit.

The effect of complete ensheathment of the repaired or reconstructed anterior cruciate ligament (ACL) in the infrapatellar fat pad was studied in a rabbit model. Four to 16 weeks after repair of a transected ACL or insertion of an autologous tendon graft these tissues were evaluated by histology and microangiography. Following ACL repair a high incidence of ligament atrophy was evident in both the ensheathed (43%) and the non-ensheathed control (54%) group. In functional ligaments a similar sequence of remodelling events was evident in both the ensheathed and the non-ensheathed group: infiltration of the transected area by mesenchymal cells, maturation of these cells to fibroblasts, and increasing organization of newly formed collagen fibres. An initial hypervascular reaction was followed by a decrease in the number and an increase in the longitudinal orientation of blood vessels. Despite a similar sequence of remodelling events, however, this process was considerably accelerated in repaired ligaments ensheathed with infrapatellar fat pad compared with non-ensheathed controls. At 16 weeks only the ensheathed repaired ACL resembled the normal ACL morphologically, even though it was still hypercellular. The tendon autograft followed a similar course from an initially avascular and acellular tissue towards a structure similar to the normal ACL. In the ensheathed ligaments and tendon grafts vascular and cellular ingrowth as well as subsequent maturation were again accelerated. This effect may be attributable to improved revascularization and cell repopulation, as well as protection from synovial fluid by the surrounding fat pad.(ABSTRACT TRUNCATED AT 250 WORDS)

[Calcareous tendinitis--special forms of the upper extremities. Clinical aspects and differential diagnosis]. / Tendinosis calcarea--Sonderformen an der oberen Extremität. Klinik und Differentialdiagnose.

Calcifying tendinitis of the shoulder joint is a relatively common condition. Its pathogenesis is well documented in anatomical-pathological terms. The clinical observation of four unusual locations in the upper limb makes us to suspect the same pathological process as in the supraspinatus location. The clinical course of calcifying tendinitis in a typical location is discussed in detail.

[Transient osteoporosis or femur head necrosis? Early diagnosis using MRT]. / Transitorische Osteoporose oder Femurkopfnekrose? Frühdiagnose mit der MRT.

Transient osteoporosis of the hip is a syndrome that does not seem to be widely known; this is also true for its radiological appearance. It is often mistaken for avascular necrosis of the femoral head, metastatic or inflammatory disease. These differential diagnoses lead to more or less invasive procedures, although transient osteoporosis does not require more than immobilisation for complete remission. MRI was done in 38 patients with acute hip pain, 13 had femoral head necrosis and 8 transient osteoporosis. Follow-up studies via MRI in patients with transient osteoporosis revealed 3 stages (diffuse, focal, residual) during the clinical course of which stage II is similar to femoral head necrosis but always without the typical sclerotic rim.

[Acute hip pain in the adult--assessment by magnetic resonance tomography]. / Der akute Hüftschmerz des Erwachsenen--Abklärung durch MR-Tomographie.

Using the modern cross-sectional imaging technique of MRI, significant improvement has been achieved in the early diagnosis of acute hip diseases, such as avascular femoral head necrosis, transient osteoporosis, coxitis, and tumors, the demarcation of which can be seen by MRI. Studies with MRI in patients with transient osteoporosis have revealed three stages during the clinical course. The focal stage is similar to femoral head necrosis, but always without the typical sclerotic rim. To obtain complete remission, transient osteoporosis only requires immobilization. There are difficulties in diagnosing infected and neoplastic processes.

[Alloplastic replacement of the anterior cruciate ligament by a polytetrafluoroethylene ligament. Animal experiment study]. / Alloplastischer Ersatz des vorderen Kreuzbandes durch Polytetrafluoräthylenband. Tierexperimentelle Studie.

4 sheep knees received an implant of polytetrafluorethylene. 18 month after implantation the clinical and histological investigation showed two cases of anterior instability and rupture of parts of the prosthesis. We sw severe degenerative lesions intraarticular with chronic inflammation characterized by the proliferation of immature fibroblasts, the accumulation of macrophages and the formation of multinucleated giant cells. The transfer of our results to the human knee is discussed.

Nuclear polymorphism in osteosarcomas as a prognostic factor for the effect of chemotherapy. A quantitative study.

A current strategy for osteosarcoma treatment is neo-adjuvant chemotherapy prior to the resection of the tumour. It appears that some tumours respond very well to the cytostatic therapy, while others show little or no effect. It is desirable to be able predict the response of the tumour before starting chemotherapy. 16 biopsy specimens from patients with osteosarcoma who had been treated according to the protocol of the study COSS-80 and COSS-82 were examined. 100 tumour cells from each biopsy have been measured by an electronic interactive image analysis system (IBAS II; Kontron/ZEISS). After completion of chemotherapy en bloc resection of the tumour was performed. The entire surgical specimen was completely examined at two levels by means of undecalcified sections, and assigned a grade for the effect of chemotherapy analogous to the grading of Salzer-Kuntschik et al. (1983). The quantitative analysis of tumour cell nuclei revealed two different patterns of nuclear sizes, which were correlated significantly with the chemotherapy response (P less than 0.002). Tumour cell nuclei of well responders were significantly larger and showed a greater variance in size (mean value 66 + 41 micron 2), than those of poor responders (mean value 38 + 18 micron 2). We conclude from our results that quantitative analysis and classification of nuclear size of osteosarcoma cells may be useful for predicting chemotherapy response in patients with osteosarcoma.