The prognostic significance of glial fibrillary acidic protein staining in medulloblastoma

Histologic and immunohistochemical properties of 53 medulloblastomas were analyzed with regard to clinical features and survival rate. No correlation was found between survival rate and histologic features of the tumor, such as desmoplastic reaction, number of mitoses, hemorrhages, necrosis, endothelial proliferation, glomerular arrangement, calcifications, rosettes, or oligodendroglial cells. However 82% of the patients with positive glial fibrillary acidic protein (GFAP) staining in numerous tumor cells survived more than 5 years; only 30% survived that long if their tumor cells were GFAP negative (P = 0.0093). This significant difference was not related to the mode of therapeutic protocol used. The authors suggest that GFAP staining may be a useful prognostic tool in medulloblastoma.     

Early stages of the pathogenesis of rat ventral prostate hyperplasia induced by citral

Typical lesions of benign prostatic hyperplasia (BPH) were induced experimentally in the ventral prostate of adolescent (6 week old) male rats by citral, a nonsteroidal compound. Incipient BPH changes were already observed in the acinar glands 10 days after citral administration. A longer period of treatment (1 month) significantly enhanced epithelial hyperplasia, whereas the stromal elements were less reactive. Characteristic BPH lesions involving both prostatic compartments were found after 3 months of treatment. Castration prior to citral administration prevented such BPH changes; however, citral did not prevent the involutive lesions of castration. The mechanism of action of citral is yet unknown, various possibilities concerning the induction of BPH in rats are presented and discussed. The potential advantage of this model, especially as BPH is not necessarily linked to age or exogenous hormones, may offer new alternative pathways for understanding the complexity of BPH pathogenesis in animals and perhaps even in man.     

Use of Vicryl mesh to support the esophageal wall after circular myotomy (Livaditis procedure) in long-gap esophageal atresia — an experimental study

Circular esophageal myotomy (CEM) is currently a well-accepted technique for elongation of the upper esophageal pouch in cases of long-gap esophageal atresia (EA). Esophageal pseudodiverticulum is a frequent and perhaps underreported sequela of this technique, characterized by ballooning or outpouching of the esophageal mucosa in the myotomized area. The present study was designed to seek a supplement for the CEM technique in order to avoid possible pseudodiverticulum formation in the myotomized area. We created an animal model to simulate the anatomic conditions present after primary repair of EA facilitated by CEM. Three groups of dogs underwent either cervical (1 group) or thoracic (2 groups) esophageal myectomy. In the cervical and first thoracic groups, the denuded mucosa was left without any support. In the second thoracic group, the denuded mucosal area was wrapped with polyglactin 910 (Vicryl) mesh. In all three groups the esophagus was narrowed by a Marlex mesh ring 3 cm distal to the myectomized zone, simulating a condition resulting from anastomotic narrowing. The dogs underwent barium swallows under fluoroscopy at different postoperative periods and were killed 4 or 6 months after surgery. The esophagi were removed for gross and radiologic investigation under maximal insufflation as well as for histologic assessment. The proposed canine model proved to be useful for study of the myectomized esophagus, mimicking the anatomy and conditions after CEM in long-gap EA repair. Wrapping the denuded mucosa with Vicryl mesh fortified the weakened esophageal wall, thus diminishing the likelihood of future pseudodiverticulum development. In light of the simplicity of the technique and the absence of any evident risk or complications, we recommend that the use of Vicryl mesh wrap be considered during CEM to reinforce the esophageal wall.Supported by the Slezak Fund for Experimental Surgery (Grant #01370791)     

IgM and IgG antibody response in two immunosuppressed patients with Legionnaires' disease: Evidence of reactivation of latent infection

Two patients in whom pneumonia due to Legionella pneumophila developed while they were receiving immunosuppressive therapy had serologic evidence of prior infection with the same serogroup of L. pneumophila two and eight months prior to their clinical pneumonia. This suggests that the pneumonia in these patients may have been due to the reactivation of a latent infection, possibly due to their immunosuppressed state. A new enzyme-linked immunosorbent assay (ELISA) was developed to detect IgG and IgM antibodies to L. pneumophila, and the kinetics of these antibody responses were useful diagnostically.     

A novel anchoring system for colonic stents: a pilot in vivo study in a porcine model

Background

Colorectal stents have a proven role in colorectal cancer as palliative care or a bridge to surgery. However, their efficacy and anchoring to the tissue varies according to stent design with stent migration rates up to 50 %. We present preliminary in vivo results of a new end-luminal anchoring system for stent fixation to the rectal canal. The aim was to assess the efficacy and safety of the stent using the anchoring system while subjecting the device to daily abdominal pressures related to daily activities in a porcine animal model.

Methods

Ex vivo anatomical and physical studies were performed to improve the system’s structure and safety. Four female pigs were followed for the acute and chronic (16 weeks) period. Two animals were euthanized and underwent en-bloc pelvic visceral excision and histopathological examination. Device fixation time, animal behavior, device patency, anoscopic examination and histopathological features were assessed.

Results

Mean anchoring time was 13.83 weeks (standard error ± 1.38 weeks). One of the animals experienced early device expulsion with no complications. No obstruction was noted in any of the animals. Macroscopic examination revealed mild focal submucosal scarring in one animal and a normal examination in the other. Hematoxylin and eosin staining revealed mucosal ulceration and mixed inflammatory cell infiltrate, with no signs of granulomata, foreign body giant cell reaction or microabscess formation.

Conclusions

A novel fixation device designed for long-term intrarectal implantation was well tolerated and maintained anal canal patency without migration. Larger studies are needed before its implementation in humans.     

Is the diagnostic yield of prostate needle biopsies affected by prostate volume?

ObjectivesTo determine the effect of prostate volume on the diagnostic yield of prostate biopsies.Materials and methods155 consecutive patients underwent 12-core transrectal ultrasound guided needle biopsies. Data were collected prospectively on age, serum PSA, digital rectal examination (DRE), previous prostate biopsies, prostate volume and pathologic result. Univariate and multivariate logistic regressions were undertaken to determine the effect of prostate volume on the risk for a positive biopsy.Results45 patients (29%) were diagnosed with cancer. The median patient age was 63 (range 48–82) years, the median PSA level was 6.7 ng/ml (0.5–156 ng/ml), and the median prostate volume was 57 ml (16–273 ml). 42 patients (27%) had an abnormal DRE and 51 (33%) had undergone previous prostate biopsies. Positive biopsy rates were 39%, 33%, and 14% for prostate volume below 46 ml, between 45 and 73 ml, and above 72 ml, respectively. Univariate analysis showed that age, serum PSA, DRE and prostate volume were all associated with a positive biopsy. Multivariate analysis adjusted for age, PSA and DRE showed a significant risk increase for a positive biopsy in smaller prostates. (OR = 5.6 95% CI 1.75–17.89; and 8.86 95% CI 2.72–28.82, for prostate volume between 45 and 72 ml and below 45 ml, respectively).ConclusionThe diagnostic yield of prostate biopsies is significantly lower in large prostates. As the result the standard 12-core biopsy may be insufficient for the diagnosis of cancer in large prostates.     

Intermediate and High-Grade Gastric Non-Hodgkin's Lymphoma: A Prospective Study of Non-Surgical Treatment with Primary Chemotherapy, with or without Radiotherapy

The role of surgery as initial treatment in gastric lymphoma remains controversial. We have prospectively evaluated a stomach conservation strategy in histologically aggressive gastric lymphoma, using primary adriamycin-containing chemotherapy, followed by involved-field radiotherapy in patients with limited disease. Twenty-six patients (median age 69 years) were entered in this study; 15 had stage I disease, 7 had stage II disease and 4 had stage IV disease. The chemotherapy combinations were CHOP (18 patients) and ProMACE/MOPP (8 patients). Radiotherapy was given to 11 patients. Of the 24 patients evaluated for response, 18 (75%) achieved endoscopically-confirmed complete response and 4 (17%) partial response. During follow-up (median 22 months), none of the complete responders developed recurrent lymphoma. Gastric resection was performed in 1/26 patients who did not respond to primary chemotherapy. There were no cases of perforation, but three patients (12%) developed acute gastro-intestinal bleeding a few days after the onset of chemotherapy, one of whom required a surgical devascularization procedure. There was no treatment-related mortality. These data further support the non-surgical approach in histologically aggressive gastric lymphoma, using primary chemotherapy with or without radiation therapy.     

Transient bone oedema of the tibia mimicking a tumorous process

The authors describe a distinct clinical entity consisting of bony tenderness, increased isotope uptake along the metaphyses and/or diaphyses and magnetic resonance changes simulating a bone marrow-replacing lesion. Bone biopsies indicate the presence of bone marrow fibrosis and some new bone formation. Nine such cases were prospectively evaluated according to a standardized protocol including clinical examination, x-rays, bone scan and CT scan as well as MRI scans including contrast medium injection. All patients presented with tibial tenderness. In one case the bone was noticeably thicker as compared to the other side. The ages ranged from 6 years to 64 years and 6 of the patients were female. Xrays were normal in 6/9 patients; the rest had minimal periosteal reaction, and mild intramedullary sclerosis. Uniform imaging findings were longitudinal increased uptake along the metadiaphysis of the tibia on bone scans, and increased bone marrow density on CAT scans without a fracture line. A magnetic resonance study indicated bone marrow replacement as demonstrated by an area of low signal intensity on T1-weighted images and high signal intensity on T2-weighted images. Some enhancement of signal was observed following gadolinium injection. This clinical entity, which the authors attribute to be a medullary stress reaction, is self-limited, and pain resolves within 3 months. However the radiographic changes appear to be permanent. A biopsy is not required provided no cortical penetration or soft tissue mass is demonstrated by MRI scan.     

Pigmented epithelial tumours of the conjunctiva.

Two out of 60 conjunctival epithelial tumours reviewed between 1973 and 1989 were found to be pigmented. One tumour was a pigmented papilloma and the other a pigmented squamous cell carcinoma. The melanin pigment was found in epithelial tumour cells as well as in macrophages, dendritic melanocytes, and Langerhans cells. The distinction between the latter two types of cells was possible in one of the tumours only. Both tumours were found in dark-skinned white patients without any evidence of conjunctival acquired melanosis.