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Biomedical subjects

A J Gross

Publications and source records attributed to A J Gross.

At least 19 recordsLinked to original sources
PubMed2001

Differences in cortical microcirculation in the kidneys of unilaterally congenital hydronephrotic rats.

The surgically induced split hydronephrotic kidney has been generally accepted as a valid model for the assessment of renal microcirculation by means of intravital microscopy. Whereas nearly all previous work on this issue has been done with a transillumination technique, we used an epiillumination model that is suitable for investigation of microvascular perfusion in both normal and hydronephrotic kidneys without surgical manipulation of the ureter. By means of the congenital unilaterally hydronephrotic Tauchi rat, microcirculation of the hydronephrotic and that of the nonhydronephrotic kidney were compared. For that purpose both the hydronephrotic and the nonhydronephrotic kidneys of Tauchi rats were exteriorized on a specially designed microscopy stage. After injection of FITC-dextran and rhodamine 6G, microvascular perfusion was assessed in both kidneys. The new model allowed visualization of arterioles, capillaries, and postcapillary venules in both the hydronephrotic and the nonhydronephrotic kidneys. Glomeruli could only be regularly seen in the hydronephrotic kidney, but also in some normal kidneys. Capillary blood cell velocity was significantly higher in the hydronephrotic kidneys (0.67 +/- 0.03 mm/s) compared to the normal kidney (0.32 +/- 0.05 mm/s; P < 0.05), whereas capillary diameters were smaller (4.2 +/- 0.02 microm vs. 5.7 +/- 0.2 microm; P < 0.05). In addition, the hydronephrotic kidney showed a significantly lower density of perfused microvessels compared to the normal controls. Epiillumination intravital microscopy allows assessment of the cortical microcirculation in both the hydronephrotic and the nonhydronephrotic kidneys without surgical induction of hydronephrosis. The hydronephrotic kidney shows significant microcirculatory differences compared to normal kidneys that should be taken into account when using a hydronephrotic model for pharmacological testing.

Animals↗
PubMed2001

Rupture of an abdominal aortic aneurysm due to aortic wallstent dislocation masquerading as renal colic.

Placement of an aortic wallstent for treatment of an abdominal aortic aneurysm (AAA) is a frequent therapeutic measure. Whereas AAA is known to mimic renal colic, aortic wallstent dislocation is a novel diagnostic problem. Herein, we report the first case of a patient with a dislocated aortic wallstent and subsequent aneurysm rupture and discuss appropriate diagnostic measures.

Aged↗
PubMed2000

Regression of human metastatic renal cell carcinoma after vaccination with tumor cell-dendritic cell hybrids.

Reports of spontaneous regressions of metastases and the demonstration of tumor-reactive cytotoxic T lymphocytes indicate the importance of the host's immune system in controlling the devastating course of metastatic renal cell carcinoma. Recent research indicates that immunization with hybrids of tumor and antigen presenting cells results in protective immunity and rejection of established tumors in various rodent models. Here, we present a hybrid cell vaccination study of 17 patients. Using electrofusion techniques, we generated hybrids of autologous tumor and allogeneic dendritic cells that presented antigens expressed by the tumor in concert with the co-stimulating capabilities of dendritic cells. After vaccination, and with a mean follow-up time of 13 months, four patients completely rejected all metastatic tumor lesions, one presented a 'mixed response', and two had a tumor mass reduction of greater 50%. We also demonstrate induction of HLA-A2-restricted cytotoxic T cells reactive with the Muc1 tumor-associated antigen and recruitment of CD8+ lymphocytes into tumor challenge sites. Our data indicate that hybrid cell vaccination is a safe and effective therapy for renal cell carcinoma and may provide a broadly applicable strategy for other malignancies with unknown antigens.

Aged↗
PubMed2000

Antibiotics and return visits for respiratory illness: a comparison of pooled versus hierarchical statistical methods.

BACKGROUND: Antibiotic prescribing for respiratory illness has been associated with small reductions in return visits in an analysis of a large practice-based network. In this study, we apply hierarchical analytical methods that account for the clustering of patients by practices to identify whether antibiotic prescribing by primary care physicians reduces subsequent visits for 6 acute respiratory illnesses-upper respiratory infection, pharyngitis, bronchitis, otitis media, sinusitis, and cough. METHODS: The study data came from 318 family physicians and internists in 45 practices in the Practice Partner Research Network from January 1995 through December 1996, with 255,564 active patients. Patients treated with antibiotics were compared with those who were not on the frequency of revisit within the next 14 days. A simple pooling model and 3 hierarchical statistical models (fixed-effects, random-effects, and Bayesian) were used to compare the odds-ratios for return visits. RESULTS: Statistically significant results were found only for bronchitis and sinusitis by the hierarchical models, but the simple pooling model produced statistically significant results for all study conditions. CONCLUSION: We conclude that antibiotics may reduce return visits for patients with bronchitis and sinusitis, but not for patients with other respiratory illness (upper respiratory infection, pharyngitis, otitis media, or cough). Studies of large clinical databases should use methods of analysis that account for the grouping of patients by practice to avoid false positive associations (type I errors.)

Academic Medical Centers↗
PubMed1999

Goethe almost died of urosepsis.

In the year of 1805, Goethe almost died of urosepsis. His urological problems were not diseases arising from full health but a new variation in a life accompanied by illnesses. Some sources date the first colics he experienced to the year 1795 and others say 1805. The most dramatic period in the course of his illness was in February, when he suffered from fever of such an extent that one could speak of urosepsis. Recovery took place slowly and was accompanied by minor relapses. Nothing about this is written down in his work. On the advice of his doctors, Goethe undertook a cure in Lauchstädt in July and August. The report of his consultant, Professor Johann Christian Reil, on his problems in the field of urology remained undiscovered until 1937. Professor Reil recommended treatment with thermae carolinae, aqua calcis, soap soda crystallisata, herbae subastringentes, and uva ursi, among other measures. With increasing age, Goethe's colics disappeared. The passing of a stone has never been described. Whereas Goethe hinted about medical problem other than those reported herein, the urological problems discussed in this article were left unmentioned. Nonetheless, literature that deals with Goethe's diseases is interesting from the aspect of both the history of medicine and the history of culture.

Bacteremia↗
PubMed1999

Erectile dysfunction caused by sacral gun-shot injury.

A 22-year-old man suffering from isolated erectile dysfunction associated with damage to the right spinal nerve S2 caused by sacral gun-shot injury. He has no loss of bladder innervation. Treatment has been implantation of a penile prosthesis.

Adult↗
PubMed1999

Human small cell lung cancer cells produce brain natriuretic peptide.

The tumoral production of brain natriuretic peptide (BNP) was studied using 9 small cell lung cancer (SCLC) cell lines which were established from patients with small cell lung cancer. BNP cDNA fragment was generated from 20 microg total RNA which was prepared from the human right cardiac atrium by reverse transcription-based polymerase chain reaction. Expression of BNP mRNA was detected in 30 microg total cellular RNA from these cell lines by RNase protection assays in 5 of 9 SCLC cell lines. Radioimmunoassays using 125I-radiolabeled human BNP(1-32) and antihuman BNP(1-32) antibody detected immunoreactivity in cell pellets from SCLC cell lines which had detectable BNP mRNA. BNP immunoreactivity in the cell pellets corresponds with the data from BNP mRNA analyses. We conclude that SCLC cells have detectable BNP mRNA by RNase protection assay and BNP immunoreactivity in the cells.

Carcinoma, Small Cell↗
PubMed1998

Push and smash increases success rates in treatment of ureteric calculi by ESWL.

During a 3-year period 105 patients underwent attempted retrograde manipulation for ureteric calculi into the renal pelvis prior to extracorporeal shock wave lithotripsy (ESWL). The success rate of this group was compared to 93 patients receiving ESWL of ureteric calculi in situ. The method of retrograde manipulation was recorded prospectively. Retrograde flushing with a 5 F Tiemann ureteral catheter was performed after coating the proximal ureter and renal pelvis with a mixture of saline and lidocaine gel. Success rate of calculi push was 91.4%. Mean number of ESWL treatments in this group of patients was 1.4, compared to 2.1 in patients with in situ treatment. Reposition of ureteric calculi prior to ESWL treatment increases successful initial treatment and can be performed easily.

Anesthetics, Local↗
PubMed1998

[Treosulfan displays cytotoxic effect on spheroids of primary cell cultures of renal cell carcinoma independent of p-glycoprotein expression].

Therapy of advanced renal cell carcinoma remains difficult. New therapeutic schemes besides cytokine treatment should be evaluated. The following study analyzes the in vitro toxicity of treosulfan on spheroids of 8 primary cultures of renal cell carcinoma cells. these data were compared to the toxicity of vinblastine. All investigations were performed in regard to the P-glycoprotein (Pgp) expression of the cells, which is one of the main causes of multidrug resistance. Four Pgp positive and four Pgp negative spheroids were incubated with the drugs in increasing doses. Toxicity was measured using the MTT toxicity assay as well as trypan blue exclusion. Significantly higher toxicity of treosulfan compared to vinblastine could be demonstrated. In addition, the effects of treosulfan were not related to Pgp expression. These results are encouraging and a phase II study analyzing the efficacy of treosulfan in patients with advanced renal cell carcinoma has been initiated in our institution.

Antineoplastic Agents, Alkylating↗
PubMed1998

Treatment of transplant ureteral stenosis with Acucise endoureterotomy.

Treatment of ureteral stenosis has been attempted in many patients with transplanted kidneys. Treatment with the Acucise catheter system is a new approach for such patients. Published results of the approach in eight patients promise safety, effectiveness, and low perioperative morbidity. We report two cases of transplant ureteral stenosis treated with Acucise. One patient with stenosis of the pyeloureteral junction was treated successfully and has been free of recurrence for 9 months. The other patient had long-distance stenosis of the lower portion of the transplant ureter. Acucise incision was successful, but the patient had to undergo uretero-neocystostomy because of a ureteroperitoneal fistula. We use these cases to illustrate the disadvantages of endourological ureteral surgery as a standard therapeutic approach after renal transplantation. We suggest that Acucise is reliable when used in patients with uncomplicated short-distance ureteral stenosis; however, patients with long-distance stenosis or stenosis caused by heavily scarred periureteral tissue will not profit from it because of a higher complication rate.

Adult↗
PubMed1998

Metastasis from renal cell carcinoma to the cervix uteri.

We report on a patient with clear cell adenocarcinoma of the left kidney and a solitary metastasis to the cervix uteri. Metastases from renal cell carcinoma to the female genitalia are uncommon and metastatic involvement of the uterus is very rare. To our knowledge, no more then five cases have been published. A review of the literature is given.

Aged↗
PubMed1997

In vitro investigations of new therapeutic agents on bladder tumor cell lines.

In this study sensitivity of human transitional cancer cells to the anticancer agent paclitaxel, an antimicrotubular drug, and to gallium nitrate, a group IIIa metal, was compared to that of the standard MVAC (methotrexate, vinblastine, doxorubicin and cisplatin) drugs. The reduction of cell proliferation was evaluated after 48 h of incubation of six different cell lines with each agent using the mean transit time (MTT) assay. We investigated both monolayers and spheroids. Paclitaxel showed significantly higher growth inhibitory effects on monolayers than vinblastine, both agents targeting the antimicrotubular apparatus. This could not be reproduced on spheroids, where a survival fraction of 50% was observed even at high concentrations (10 microM). High concentrations of gallium nitrate were needed to achieve sufficient toxicity. These concentrations are beyond the concentration achievable by systemic application. Our findings suggest that paclitaxel may be a clinically useful agent for systemic and intravesical use in bladder cancer.

Antibiotics, Antineoplastic↗
PubMed1997

[Influence of DNA ploidy and grading on survival in primary metastatic prostate carcinoma].

An aneuploid pattern of prostatic cancer defined by flow cytometry was shown to be of value in predicting progression rates and patient survival times. We evaluated the long-term value of DNA analysis in prostatic cancer in 61 patients with advanced disease. We performed flow cytometry on 61 fresh prostate specimens obtained-from a transrectal needle biopsy or a transurethral resection. All patients received antihormonal therapy. Time until death was evaluated in all patients. Of the DNA histograms analyzed, 37% showed a diploid pattern, 63% an non-diploid pattern, and 37% a tetraploid or hypertetraploid pattern. Kaplan-Meier plots were generated for analysis of the probability of survival. Mean survival time was 44 months for patients with diploid (range 1-126 months) and 40 months for patients with non-diploid tumors (range 1-96 months). This difference is not statistically significant. However, the combination of non-diploid and low-differentiated (G3) tumors reduced survival time significantly (mean 20 months, range 1-62 months). There was no patient with combination of a diploid and highly differentiated tumor.

Aged↗