Prospective analysis of multifocality in renal cell carcinoma: influence of histological pattern, grade, number, size, volume and deoxyribonucleic acid ploidy

In an effort to characterize more fully multifocal renal cell carcinoma, 100 radical nephrectomy specimens with localized renal cell carcinoma were analyzed in a prospective fashion. Analysis of each specimen consisted of preoperative computerized tomography or magnetic resonance imaging, standard pathological examination with frozen section and 3 mm. step sectioning under magnification. Multifocal renal cell carcinoma was found in 16 specimens. Multifocal disease was suspected by preoperative imaging in 7 specimens (44%) and confirmed after standard pathological investigation in 10 (63%). Papillary and mixed histological patterns occurred at a significantly increased rate in specimens with multifocal disease (p = 0.011). Other parameters, such as stage, tumor size and volume, histological grade and deoxyribonucleic acid ploidy were evaluated and did not correlate with the presence or extent of multifocality. The number of secondary tumors per specimen varied from 1 to 50 (median 2) and were of higher grade in 3 (19%) and of lower grade in 2 (12%) when compared with the predominant tumor. In conclusion, information from preoperative and to some degree intraoperative tests (except histological pattern) cannot reliably predict multifocality. The true risk for unknown multifocality in a surgical setting seems to be 6%, which roughly corresponds to the incidence of locally recurrent disease in published large institutional series.

The downregulation of GAP-43 is not responsible for the failure of regeneration in freeze-killed nerve grafts in the rat

Freeze-killed nerve grafts in rats are able to support limited axonal regeneration from severed peripheral nerves, but by 6 weeks postoperation, axonal elongation through the grafts ceases. To find out whether this limited regeneration may be related to GAP-43 expression, 4-cm freeze-killed nerve grafts were attached to the proximal stumps of severed tibial nerves in adult inbred Fischer rats. For comparison, tibial nerve crush, to allow functional regeneration, or section and ligation, which allows only abortive axonal sprouting, were also performed. After survival for 3 or 6 weeks, the lumbar spinal cord and L4 dorsal root ganglia were stained for GAP-43 mRNA. Freeze-killed grafts of 3-8 weeks duration were processed for GAP-43 immunocytochemistry. Three weeks after all three operations, comparable numbers of axotomized spinal motorneurons and primary sensory DRG neurons reexpressed high levels of GAP-43 mRNA. Six weeks after tibial nerve crush, the number of tibial motorneurons and DRG cells expressing GAP-43 mRNA returned to control levels but after section and ligation or freeze-killed nerve grafting many positively stained cells were still visible. GAP-43 immunoreactivity was detectable using immunocytochemistry in many unmyelinated axons which had regenerated into the freeze-killed grafts at all times. Both axonal profiles in contact with Schwann cells and those which lacked such contact were GAP-43 positive. These results suggest that the cessation of axonal regeneration into freeze-killed tibial nerve grafts is not the result of a down-regulation of GAP-43. Furthermore, the presence of high levels of GAP-43 alone is not sufficient to ensure prolonged axonal regeneration.

Antagonism of androgen action in prostate tumor cells by retinoic acid

Recent studies have demonstrated that retinoic acid (RA) can repress the growth of human prostatic epithelial cells. Since the proliferation of prostate cells is highly dependent on androgen stimulation, presumably via its cognate receptor, we investigated the effects of RA on the expression of the androgen receptor and other androgen-regulated genes in the human prostatic adenocarcinoma cell line LNCaP. Using a radioligand binding assay, we found that androgen-binding activity was reduced 30-40% in cells treated with 10(-5) M RA plus 6 nM dihydrotestosterone (DHT), as compared to cells with the androgen alone. Moreover, the reduction of the androgen receptor (AR) was not accompanied by alteration of the ligand-binding affinity. Concomitant changes in the function of AR were manifested by a dramatic reduction in AR-mediated transcription activity in a transfection experiment. Androgen-induced levels of both prostate-specific antigen (PSA) and human glandular kallikrein-1 (hKLK2) mRNAs were significantly repressed by RA in a dose- and time-dependent manner. Consistent with this finding, androgen induction of PSA glycoprotein was also repressed by RA, with maximal inhibition occurring at 10(-5) M. These data suggest that the suppression of proliferation and function of prostatic cells by RA may be via modulatory effects on the AR.

Helicobacter pylori reinfection rate, in patients with cured duodenal ulcer

OBJECTIVE

To determine the reinfection rate of the gastric mucosa in patients previously cured of duodenal ulcers, following the eradication of Helicobacter pylori. Only those remaining H. pylori-negative beyond 12 months of follow-up were studied, to minimize the potential inclusion of patients with H. pylori recrudescence.

METHODS

Patients with endoscopically proven duodenal ulcers who had been treated with triple therapy, resulting in documented eradication of H. pylori and cure of the ulcer for at least 4 years, were recalled and had their H. pylori status determined by the 14C-urea breath test. Those found positive for H. pylori underwent endoscopic confirmation of the infection.

RESULTS

Of the 94 patients restudied, with a follow-up period range of 48-96 months or a total of 549.8 yr, only two (2.2%) were again H. pylori positive. This gives an effective reinfection rate of 0.36% per patient year. In the two H. pylori-positive patients, one had normal mucosa endoscopically, whereas duodenitis without active ulceration was present in the other. The former was asymptomatic, whereas the latter patient was using ranitidine daily for symptom control.

CONCLUSION

In the Australian setting, following cure of duodenal ulcer disease by eradication of H. pylori, subsequent reinfection is an unusual phenomenon. We conclude that efforts aimed at eradication of H. pylori in duodenal ulcer are justified and are worthwhile.

Use of high efficacy, lower dose triple therapy to reduce side effects of eradicating Helicobacter pylori

OBJECTIVES

To evaluate two triple-therapy (TT) regimens of colloidal bismuth subcitrate (CBS), metronidazole, and tetracycline HCl in eradicating Helicobacter pylori, with particular attention to the frequency of resulting adverse effects of the two therapies.

METHODS

A prospective, randomized controlled trial was conducted in patients with symptoms of dyspepsia who were positive for H. pylori. Subjects received a 14-day course of either 4 x/day therapy of CBS (108 mg), tetracycline HCl (500 mg), and metronidazole (250 mg), or 5 x/day therapy of CBS (108 mg), tetracycline HCl (250 mg), and metronidazole (200 mg). H. pylori status was determined endoscopically by urease test, histology, and culture. Standard questionnaires were administered to determine compliance to treatment and side effects of therapy.

RESULTS

H. pylori was eradicated in 196/213 (92%) patients in the 4 x/day group and 202/210 (96%) in the 5 x/day group (p = 0.07). Side effects were significantly less frequent and less severe in the 5 x/day group (p < 0.01).

CONCLUSIONS

We conclude that a lower dose, 5 x/day triple therapy treatment of H. pylori is equally efficacious to the standard 4 x/day therapy, but is accompanied by fewer and milder adverse effects.

Q-T interval as predictor of serum calcium level

To assess whether measurement of the electrocardiograhic (ECG) Q-T interval is a useful predictor of total serum calcium concentration, 15 uraemic patients were studied (10 female, five male; age range, 25-60 years). Resting ECGs were interpreted by three independent observers without knowledge of the patients' identity or serum calcium. Three variants of measurement of the Q-T interval were analysed, of which Q-aTc, the interval from the beginning of the Q-wave to the apex of the T-wave, was the most consistent (coefficient of variation, 2.7%). This also provided the best correlation with measured serum calcium concentration (P < 0.001). When compared to biochemical measurements, the predicted serum calcium concentration was within 95% confidence limits in 14 of the 15 patients studied. However, the wide confidence limits of this technique mean that it cannot be recommended in routine clinical practice.

A phase I and pharmacokinetic study of intraperitoneal carboplatin and etoposide

BACKGROUND

We attempted to determine the maximum tolerated dose and toxicity of etoposide (VP-16) when administered in combination with carboplatin (CBDCA) (300 mg m-2) and administered via the intraperitoneal (IP) route.

METHODS AND MATERIALS

A total of 26 patients were treated on this trial. CBDCA was administered at a fixed dose of 300 mg m-2) while VP-16 was started at a dose of 200 mg m-2 and escalated at 50 mg m-2 increments. Both agents were mixed together in 2 litres of 5% Dextrose and administered as quickly as possible into the peritoneal cavity. Pharmacokinetic studies were performed at the maximum tolerated dose (MTD).

RESULTS

The MTD for this regimen was CBDCA 300 mg m-2 and VP-16 350 mg m-2. Patients > or = 70 years of age or who had received more than six cycles of previous chemotherapy, tolerated this regimen poorly. The MTD for this group of patients was CBDCA 200 mg m-2 and VP-16 50 mg m-2. Neutropenia was the dose limiting toxicity for both groups. The mean peritoneal/plasma peak ratio was 18.3 for CBDCA and 12.7 for VP-16. The pharmacologic advantage (peritoneal/plasma AUC ratio) was 14.9 for CBDCA and 8.8 for VP-16. Although measurable disease was not a requirement for entrance into this study a response rate of 27% was noted in 15 patients with evaluable disease who had ovarian cancer.

CONCLUSIONS

A pharmacologic advantage exists for both CBDCA and VP-16 when administered together via the IP route.

Apparent reversal of early gastric mucosal atrophy after triple therapy for Helicobacter pylori

Helicobacter pylori may be difficult to detect in individuals with intestinal metaplasia or atrophic gastritis, even though bacteria may persist in the mucosa in low numbers, maintaining elevated serum H. pylori antibody levels. We report a patient with marked, endoscopically visible gastric mucosal changes and focal changes of histological atrophic gastritis, who was negative for H. pylori on urease test, culture, and histology, but had positive H. pylori serology. When treated with triple therapy and reassessed at 6 months, his H. pylori antibody titer fell to low/negative levels, abnormal mucosa was replaced by a velvety, normal lining, and the previous evidence of histological atrophic gastritis was no longer detectable.

Organochlorine pesticides and polychlorinated biphenyl congeners in commercial fish from the Great Lakes

Fillets from 11 species of commercial fish from the Great Lakes were analyzed for residues of 39 polychlorinated biphenyl (PCB) congeners and 24 other organochlorine compounds. Eel and trout contained the highest amount of PCB (753 and 633 ppb wet weight, respectively) and other organochlorines (607 and 1404 ppb, respectively); perch and carp contained the lowest residues. The penta- and hexachlorinated PCBs were the major congeners in all species except whitefish, in which the tetrachlorinated congeners predominated. Toxaphene was the most abundant organochlorine pesticide in trout; p,p'-DDE was the major component of this class in eel. Residue concentrations in commercial carp were compared with residues present in carp from a fishery closed to commercial operation. Although both PCB and organochlorine pesticide levels in carp were among the lowest for all commercial fish samples, levels from the contaminated area were among the highest.

Total organochlorine content of fish from the Great Lakes

Residues of polychlorinated biphenyls (PCBs) and organochlorine pesticides were determined in several species of commercial fish from the Great Lakes and compared to the total organic chlorine determined by neutron activation analysis. The mean organochlorine contents ranged from 44 to 138 ppm (lipid basis) and were 5 to 72 times higher than the contents of PCBs and organochlorine pesticides. Marine fish also contained a large proportion of unidentified organic chlorine. The unknown material in the Great Lakes fish was found to chromatograph with the high molecular weight lipid fraction by gel permeation chromatography.

Preoperative androgen deprivation therapy: artificial lowering of serum prostate specific antigen without downstaging the tumor

We studied 22 patients with clinical stage B2 (T2c) or C (T3) prostate cancer who underwent androgen deprivation therapy before radical prostatectomy as part of a downstaging protocol (group 1). The concentration of serum prostate specific antigen (PSA) was determined before and at the conclusion of androgen deprivation therapy, just before the operation. For each group 1 patient a match patient who had not received preoperative endocrine therapy (group 2) was chosen. The age of the group 2 patients was similar to that of the group 1 patients. The clinical stage of disease and pretreatment tumor grade in group 2 were identical to the stage and grade in group 1, and the serum PSA value in group 2 was similar to that of group 1 before initiation of androgen deprivation therapy. In group 1 the median serum PSA concentration was 14.8 ng./ml. (range 3.1 to 99) before endocrine therapy and 0.2 ng./ml. (range 0.1 to 3.4) after hormonal treatment. Group 2 had a median level of 13.3 ng./ml. (range 3.4 to 100). The median decrease in the serum PSA concentration for group 1 as a result of androgen deprivation therapy was 98.5%. The radical prostatectomy specimens from these 2 groups of similar patients had no difference with regard to maximal tumor dimension, pathological stage and deoxyribonucleic acid ploidy status. These findings indicate that serum PSA becomes an unreliable indicator of disease status after initiating preoperative androgen deprivation therapy and that preoperative androgen deprivation therapy has little or no benefit for decreasing the extent of tumor or pathological stage. The concept of downstaging is misleading and must be examined in a randomized clinical trial.

Quantitative analysis of stress fiber orientation during corneal wound contraction

Previous studies of actin and actin-binding proteins in corneal myofibroblasts suggest the development of a contractile apparatus composed, in part, of F-actin micro-filament bundles, i.e. stress fibers. To better understand the mechanics of wound contraction and the relationship between microfilament bundles and wound closure, we have analyzed the spatial and temporal organization of stress fibers during the process of corneal wound healing. Rabbit corneas (26 eyes) received 6 mm full-thickness, central incisions and were studied at various times for F-actin organization using en bloc (whole cornea) staining with FITC-phalloidin, as well as conventional histological techniques. 3-D datasets (z-series of 40 en face optical sections, 1 micron steps) were collected using the Biorad MRC-600 laser scanning confocal microscope at various regions within the wound. At 7 days, 3-D analysis showed randomly oriented, interconnected F-actin filament bundles (stress fibers). Between 7 and 28 days, stress fibers appeared to organize gradually into planes parallel to the wound surface, with a large population achieving a final orientation nearly parallel to the long axis of the wound. Using Fourier Transform analysis techniques, an orientation index (OI) was calculated to quantitate global fiber orientation at each time point. Analysis of variance demonstrated a significant change (P &lt; 0.001) in overall stress fiber orientation from a random distribution at day 7 to an alignment more parallel to the lateral wound borders at day 28. Overall, these data suggest that stress fibers undergo temporal changes in spatial organization that correlate with wound closure, and that wound closure does not involve the development of previously described contractile or tractional forces aligned directly across the wound.

Evolution and environment in the Hominoidea

Between 10 and 20 million years ago, a variety of hominoid primates lived in Africa, Europe and Asia. The question of which of these, if any, lie closest to the ancestries of humans and modern apes remains a lively source of debate. Recent fossil discoveries, though, shed light on the environments in which the various groups of hominoid emerged and, it is hoped, on their evolution. But the lack of a hominid fossil record before about 5 million years ago--and any fossil record for the African apes--is still a frustrating barrier.

Advances in the treatment of acquired and developmental defects of hard dental tissues

With the decline in dental caries, the dental profession and the general public have become sensitized to the "new" specialty of cosmetic dentistry. As a consequence, research in the field of dental materials for the ideal, most natural restorative materials and techniques has become a primary focus and has had a profound influence on dental education and practice. This brief article will highlight some of these newer concepts.

Radial keratotomy. II. Role of the myofibroblast in corneal wound contraction

The cellular mechanism of corneal wound contraction after radial keratotomy (RK) was studied in a feline eye model. A total of 10 cat eyes were evaluated at various times from 0-30 days after surgery. Changes in the distribution of intracellular filamentous actin, nonmuscle myosin, alpha-actinin, surface membrane alpha 5 beta 1 integrin, and extracellular fibronectin were studied using immunofluorescence and laser confocal and electron microscopy. From day 3-7, staining for fibronectin increased along the wound margin. By day 7, keratocytes adjacent to the wound margin showed increased f-actin staining with intense staining for fibronectin compared with normal keratocytes. Myosin and alpha 5 beta 1 integrin expression was very weak at this time; alpha-actinin was not found. By day 14, fibroblasts within the wound formed f-actin microfilament bundles (stress fibers) which colocalized with fibronectin. Wound-healing fibroblasts also stained positively for alpha 5 beta 1 integrin, myosin, and alpha-actinin (the latter two were colocalized). The presence of myosin and alpha-actinin in the wound fibroblasts and the re-organization of f-actin into stress fibers by day 14 correlated with the development of wound contraction. A comparison of the cellular distribution of actin, myosin, and alpha-actinin with alpha 5 beta 1 integrin 14 days after injury suggested that integrin was localized along stress fiber bundles during wound contraction. The data from this study suggest that modulation of wound gape during healing of RK wounds may involve transformation of the corneal keratocyte to a myofibroblast-like cell and the subsequent formation of intracellular stress fibers composed of f-actin, nonmuscle myosin, and alpha-actinin. Based on the colocalization of fibronectin filaments and f-actin filaments and the unique distribution of alpha 5 beta 1 integrin, these findings support the hypothesis that the tension within the wound is generated by the formation of intracellular stress fibers and the interactions between stress fibers and the extracellular matrix, mediated by specific membrane receptor molecules.

Smoking does not contribute to duodenal ulcer relapse after Helicobacter pylori eradication

Cigarette smoking is believed to be one of the major factors influencing duodenal ulcer (DU) recurrence. However, the influence of cigarette smoking on DU recurrence after the eradication of Helicobacter pylori has not been separately addressed. The aim of this study was to investigate DU relapse rate in smokers and nonsmokers, both with confirmed eradication of H. pylori. Patients with H. pylori eradication, demonstrated at endoscopy 4 wk post-treatment, were included in the study. Smoking history was obtained with a standard questionnaire, and patients were followed endoscopically, both yearly and at symptomatic recurrence, to detect anatomical DU recurrence. Of the 197 (121M:76F) patients enrolled in the study and followed for 1-6 yr, 80 (41%) were smokers, smoking 5-40 cigarettes/day. The 117 (59%) nonsmokers included 31 (26%) patients who had ceased smoking 4-20 yr ago. Another seven (9%) smokers ceased smoking during the follow-up period. In the 197 patients with eradicated H. pylori and cured DU, there has been no recurrence of ulcer, regardless of smoking status. We conclude that in patients with DU in whom H. pylori infection is eradicated, ulcer disease does not recur, as observed for up to 6 yr. Furthermore, cigarette smoking is not a risk factor for DU recurrence, provided H. pylori is eradicated.

Helicobacter pylori-negative gastric ulcer

Causes of Helicobacter pylori (HP)-negative gastric ulcers (GUs) have not previously been systematically studied. In this study we examined possible causes of HP-negative GUs. Among 115 consecutive patients with endoscopic diagnoses of GU, 71 (62%) had HP infection, and 44 (38%) were found to be HP-negative. Of the 71 HP-positive patients, 47 (66%) had no other detectable causal factors, 21 (30%) were regularly taking nonsteroidal antiinflammatory drugs (NSAIDs), and three (4%) had malignant GU. Of the 44 HP-negative patients, 29 (66%) were taking NSAIDs, two (5%) had a malignant GU, whereas 13/44 (30%) (11% of total 115) patients had no identifiable cause. These patients were classified as having "idiopathic GU." Some 38/115 (33%) GUs occurred on the lesser curve, and these were more often (p = 0.012) HP-positive (76%) than prepyloric GUs (60/115 (52%)). We conclude that although most patients have an identifiable cause of GU, around 11% will have no apparent contributing factor. HP-positive GUs are more frequently located on the lesser curve. It is now important to identify the cause of GU, because this may dictate choice of management.

Extrarenal Wilms' tumor: results of the National Wilms' Tumor Study

Extrarenal Wilms' tumor is extremely rare and occurs predominantly in children. Eight cases of extrarenal Wilms' tumor were reported to the National Wilms' Tumor Study from 1980 to 1986. Patients were followed in the study and not randomized to a particular treatment protocol. Seven patients had a favorable histology. One tumor located in the sacrococcygeal region showed immature teratoma with nephroblastic tissue. The embryogenesis of extrarenal Wilms' tumor is controversial; however, tumor containing teratomatous elements most likely represents a different embryologic origin and, therefore, should be classified separately. All eight patients were treated with operative excision and chemotherapy. Seven of the eight patients were disease-free with a mean follow-up of 34.3 months. It can be inferred from this small group of patients that the prognosis is comparable to intrarenal Wilms' tumor in the National Wilms' Tumor Study.

Oxygenating mouthguard alleviates hypoxia during gastroscopy

A randomized study was carried out to determine the effect of oxygen (3 liters/min) via a novel oxygenating mouthguard (Oxyguard) on arterial oxygenation in 242 intravenously sedated patients undergoing gastroscopy. In another group of 21 patients, a randomized crossover study of arterial oxygen saturation using either the standard mouthguard or the oxygenating mouthguard (3 liters/min) was conducted. Significant O2 desaturation (pulse oximeter reading less than 90%) occurred in 25% of patients on room air but only 3% of those on oxygen (p less than 0.001). Severe desaturation (reading less than 85%) occurred in 5% of patients on room air but was prevented by the oxygenating mouthguard. Minimum oxygen saturation levels were significantly higher in patients on oxygen (90.5 +/- 0.3%) than on air (86.5 +/- 0.5%; p less than 0.001). In the crossover group, O2 saturation was uniformly higher in the recordings of all patients using the oxygenating mouthguard. In conclusion, administration of oxygen via the oxygenating mouthguard alleviates hypoxemia during gastroscopy and prevents severe oxygen desaturation. However, hypoxemia may occur even during use of supplemental oxygen. Hence, monitoring of arterial oxygenation is recommended.

Wilms' tumor: a new cause for urinary extravasation

We report a case of Wilms' tumor associated with urinary extravasation due to tumor invasion through the renal pelvis and anterior renal capsule. Extravasation of urine exposed to tumor may lead to upstaging of the tumor and the requirement for more intensive therapy.