Unexpected photobleaching of Alexa 488 in a fixed bacterial sample during 2-photon excitation.

A sample of fixed bacterial cells was examined by immunofluorescence microscopy using an Alexa 488 conjugated secondary antibody for visualization. Excitation using visible light confirmed the expected photostability of this fluorophore; however, when using 2-photon excitation, Alexa 488 was rapidly and substantially photobleached. The unexpected instability of Alexa 488 under certain conditions may have deleterious consequences if not anticipated and accommodated in experimental protocols.

Renal ablation with absolute ethanol. Mechanism of action.

The mechanism of renal ablation by intra-arterial ethanol was studied in 16 mongrel dogs. Ethanol injection rates were varied, and light and electron microscopic studies were performed to detect early parenchymal changes in the kidneys. Pure ischemic injury was also studied as a control. Findings showed extensive parenchymal injury plays a significant role in renal ablation with permanent thrombosis as a delayed event. Acute arterial occlusion occurred with slow ethanol injection rates due to embolization by damaged blood components.

Ureteral injuries secondary to operative procedures. Report of 24 cases.

Twenty-four cases of ureteral injury are reviewed as to presentation, diagnosis, and treatment. Prevention and prompt primary repair of the injury are stressed. Ureteroureterostomy and ureteral reimplantation produce the best results. Nephrectomy is recommended only when potential of contamination of a vascular graft exists.

Can transabdominal ultrasound estimation of postvoiding residual (PVR) replace catheterization?

In 81 outpatients the postvoiding residual urine (PVR) using real-time B-mode ultrasonography (3.5 MHz transducer) was measured. For the calculation of the bladder volume the formula for an ellipsoid (V = 4/3 pi X r1 X r2 X r3) was found to be most accurate in predicting the actual volume measured by in-and-out catheterization (r = 0.982). Other volume formulas, using only one diameter of the bladder, were found to be much less accurate. For any arbitrary value of PVR, used in determining clinical management, the incidence of misjudgment by ultrasound was negligibly low. We conclude, that sonographic measurement of the PVR as a quick, noninvasive method, should replace catheterization, if the basic equipment is available. Additional information, e.g., prostate size, bladder configuration, diverticula, etc., can be obtained during the procedure without additional costs or loss of time.

Predictors of residual mass histology after chemotherapy for advanced testis cancer.

The records of 15 patients with Stage B3 or B2/C germ cell testis tumors who underwent full surgical debulking of a residual mass after completion of chemotherapy were reviewed retrospectively to look for predictors of residual mass histology. The density, character, and change in volume of the retroperitoneal mass on computerized tomography before and after chemotherapy were compared with the histology in the primary tumor and in the residual mass. One of 6 patients without teratoma in the primary tumor had a 97 percent reduction in the mass which contained residual teratoma. Two patients with residual seminoma had a 50 percent decrease in tumor volume, and both patients died of tumor progression despite salvage chemotherapy. Two patients with pure seminomas had only residual fibrosis in masses that decreased in volume by 77 and 75 percent, respectively. One of these masses was discrete and the other was diffuse. Seven of 9 patients (78%) with teratoma in the primary tumor had either teratoma (4 of 9, 44%) or carcinoma (3 of 9, 33%) in the residual mass, and the change in mass volume ranged from a 93 percent decrease to a 540 percent increase in size. All 7 patients with residual teratoma and/or carcinoma remain free of disease after observation or further chemotherapy. For the entire series, the mass density and character did not correlate consistently with the primary tumor or residual mass histology. Residual fibrosis alone or teratoma and/or carcinoma were seen with least (0 to 50%) and greatest (more than 90%) decreases in mass volume.

Intraperitoneal rupture of the bladder.

Intraperitoneal bladder ruptures are usually injuries of violent deceleration, although spontaneous ruptures have occurred in near-term pregnancies. Once diagnosis is established by a static cystogram and withdrawal films, exploration of the abdomen and repair of the bladder rupture are indicated. Complications are usually from associated injuries and not from suprapubic drainage.

Complications of radical prostatectomy and lymphadenectomy.

The technique associated with nerve-sparing radical prostatectomy has improved the likelihood of continence, especially, and certainly potency over previous techniques. With a decline in these complications, patients and physicians in increasing numbers are choosing this surgical method of elimination of the disease. Hence this review of complications of radical prostatectomy using a modified lymphadenectomy and the nerve-sparing prostatectomy (or cytoprostatectomy).

The role of lymphadenectomy in the management of renal cell carcinoma.

Skinner and deKernion's datum, like ours, suffers from the fact it is retrospective and not randomized. Therefore, it provides suggestive but not conclusive evidence that lymphadenectomy enhances the chances for survival of a patient with a given stage and grade of renal cell carcinoma. In our study, lymphadenectomy was defined as removal of the regional lymph nodes from the diaphragm to the bifurcation of the common iliac artery on the homolateral side, which was the usual type of lymphadenectomy performed in this retrospective analysis. Because information may be obtained from lymphadenectomy alone which allows a more accurate estimate of the patient's prognosis in 8 per cent of the cases, and because our data suggest a statistical improvement in survival in patients with stage C and D disease if lymphadenectomy is performed, it is recommended that patients undergoing radical nephrectomy for renal cell carcinoma have a regional lymphadenectomy performed at the same time. It is also recommended that a prospective randomized study of th role of lymphadenectomy in patients with a given stage and grade of renal cell carcinoma be undertaken.

Renovascular hypertension following renal transplantation.

The authors address the multifactored origins of renovascular hypertension following renal transplantation and present the experience with digital subtraction angiography and percutaneous transluminal angioplasty as well as standard angiography and surgical repair in the diagnosis and treatment of transplant renal artery stenosis. The roles of the renin-angiotensin system of the native kidney and of the allograft in sustaining hypertension after transplantation are reviewed in detail.

Osteolysis after total knee arthroplasty without cement.

The prevalence and characteristics of osteolysis were studied after 174 consecutive total knee arthroplasties, performed without cement; 16 per cent (twenty-seven) of the implants (in twenty-six patients) were identified as being associated with osteolysis. The diagnosis was made an average of thirty-five months after the operation. Fifteen (56 per cent) of the twenty-seven prostheses were revised after an average of forty-five months in situ. The remaining twelve implants were still in situ five years or more postoperatively. In the patients who were managed with revision, six implants were judged to be stable radiographically and intraoperatively. The remaining nine implants were loose. The average age of the patients who had osteolysis was sixty-three years, and the average weight was seventy-six kilograms (168 pounds). Eighteen of the twenty-six patients who had osteolysis were women. The medial aspect of the tibial metaphysis was the most common site for resorption of bone (twenty-four knees). Sequential radiographs demonstrated progressive extension of the osteolytic process around the tibial base-plate of the prosthesis and distally into the tibial metaphysis along the screw-bone interface in all patients. Histological evaluation of tissue obtained at the revision procedures revealed sheets of histiocytes and occasional giant cells. Intracellular particulate polyethylene and metal were found; most particles were less than one micrometer in size, although particles as large as three micrometers were identified. Mechanical failure of the thin, modular, polyethylene tibial insert; excessive abrasion of the prominent polyethylene tibial eminence, with secondary wear and impingement of the pin on the femoral component; and failure of the metal-backed patellar component all contributed to the extensive amount of polyethylene and the variable amount of metal debris that were generated. Corrosion between the angulated titanium screws and the cobalt-chromium base-plate also contributed particulate metal to the osteolytic process locally. This study demonstrated that osteolysis occurs in association with cementless total knee replacement.

Soft-tissue balance and alignment in medial unicompartmental knee arthroplasty.

We reviewed two similar groups of patients with medial osteoarthritis of the knee treated by unicompartmental arthroplasty. The group receiving an Oxford meniscal-bearing implant, with no medial release, showed significantly better mechanical alignment than that receiving a fixed-bearing implant. Under-correction, with its ominous mechanical implications, was much more common with the fixed-bearing design. Over-correction was rare and was seen in both designs about equally. Degenerative stenosis of the intercondylar notch was common and appeared to put the anterior cruciate ligament at risk of rupture, especially after correction of the varus deformity. We consider that postoperative leg alignment and soft-tissue balance after unicompartmental knee replacement are determined more by the implant design and the surgical technique than by any variation in soft-tissue contracture. Release of the medial collateral ligament is not necessary for realignment, but a generous notchplasty is often needed to allow normal anterior cruciate ligament function.

Comparison of the early healing course of porous titanium with hydroxyapatite-coated porous titanium hip implants: clinical considerations for the use of hydroxyapatite coating in total hip replacement.

The role of hydroxyapatite (HA) coating in the fixation of human total joint prostheses remains to be established. Results of animal studies have been favorable, showing very rapid bone formation with a corresponding increase in bone-implant bond strength. In addition, the quantity of bone may be increased. This study compared identical porous titanium primary total hip implants with and without HA in similar patient populations. All of these patients were healthy and reliable, and had optimal bone geometry and bone quality for cementless fixation. The purpose of the study was to contrast the sequence of events, in the first year after surgery, between the two implant groups to identify the contribution of HA to early patient function and early radiographic appearance of the prosthesis. No significant clinical difference could be demonstrated between the two groups at 1 year from surgery. However, the HA group progressed more rapidly when comparing clinical scores at 6 months (P = .0058), and appeared to demonstrate more rapid bone remodeling at 6 months on the femoral side, although this observation did not quite make statistical significance (P = .0618). There was no difference between the acetabular components during the course of this study.

Proximal femoral allografts in revision total hip arthroplasty.

The senior authors have performed 141 proximal femoral whole-bone allografts in failed total hip reconstruction. The results of the first 50 have been previously reported. This study reviews 70 additional cases performed since 1987 and reflects improved technique and several different junctional constructs. Modest improvements in the rate of union (64% v 80%) and of dislocation (28% v 16%) have been achieved. The infection rate (6% v 4%) and demographics of the groups have remained constant. The frequency of complications (67% v 53%) has decreased, but unfortunately remains high. A step-out allograft junction with a long lateral sleeve has been the most reliable construct.