The histopathology of injury to the accessory malleolar ossification center.

The evaluation of a traumatic lower limb amputation specimen revealed an incomplete fracture between the main and accessory malleolar ossification centers. This was not associated with extensive subperiosteal or intraarticular bleeding. This pattern of injury, without any displacement or completion to an unstable fracture, should be considered in a patient with specific tenderness over a malleolus after a twisting injury or direct blow to the ankle.

Tibia valga after proximal metaphyseal fractures in childhood: a normal biologic response.

Seventeen children with 19 proximal tibial metaphyseal fractures were followed-up between 2 and 7 years after injury. Detailed measurements of the metaphyseal/diaphyseal/metaphyseal distances medially and laterally on the injured and noninjured sides demonstrated overgrowth. In four patients, the medial distance of the injured tibia was longer than the lateral distance, which was the same distance as the uninjured tibia. In 11 patients, there was an overgrowth of both the medial and lateral sides of the injured tibia, compared to the unijured tibia, and in each instance, the medial distance of the injured tibia was always longer than the lateral. In a patient with bilateral metaphyseal fractures, the medial length exceeded the lateral length in both tibias. In the child with metaphyseal and diaphyseal fractures, the medial side of the tibia with the metaphyseal fracture was the longest of the four measurements. In five of six patients with Harris lines, there was distal as well as proximal tibial metaphyseal overgrowth, but the distal line was always parallel to the physis and did not contribute to the valgus angulation. Thus there was not only a generalized increased growth proximally and distally, but there also was an eccentric proximal medial overgrowth in every patient.

Monitoring considerations in recombinant human erythropoietin therapy.

Effective monitoring of chronic hemodialysis patients treated with recombinant human erythropoietin (r-HuEPO; EPOGEN [epoetin alfa], AMGEN Inc, Thousand Oaks, CA) includes an initial evaluation of the patient, the patient's anemia, and the patient's iron stores. Assessment of iron stores includes obtaining hematocrit and hemoglobin levels, reticulocyte count, red cell indices, serum ferritin level, transferrin percent saturation, and the patient's transfusion history. If iron stores are inadequate to support the increased erythropoiesis induced by the therapy, appropriate iron replacement therapy should be provided. Monitoring also involves assessment of BP (and its control), because development or exacerbation of hypertension is the most significant side effect associated with this treatment. Because the dose-response relationship for r-HuEPO therapy has been clearly documented, a target hematocrit and target rate of increase in hematocrit can be established. As anemia improves, continued monitoring of hematocrit, hemoglobin, red cell indices, serum ferritin level, and transferrin percent saturation will ensure that depleted iron stores are noted and treated as necessary. Heparin requirements during dialysis, blood chemistries, and blood access problems should also be monitored. No data currently exist suggesting that dialyzer reuse is compromised by r-HuEPO therapy. Quality-of-life surveys show improvement with r-HuEPO treatment and effective reduction of anemia. There is also some indication that morbidity is lessened and survival improved when anemia is treated with r-HuEPO therapy.

Iron status in patients receiving erythropoietin for dialysis-associated anemia.

Adequate body iron stores are crucial to assuring rapid and complete response to recombinant human erythropoietin (rHuEPO). In the present study, markers of iron storage were examined in 27 patients with normochromic, normocytic anemia undergoing acute rHuEPO (150 to 300 U/kg t.i.w.) treatment for anemia. We calculated projected iron needed for new hemoglobin synthesis from the difference between initial and target hemoglobin concentrations, initial iron reserves available from initial serum ferritin levels, and net projected surplus or deficit from the difference between needs and reserves. Of 22 patients predicted to develop iron deficiency (mean projected deficit 268 +/- 70 mg), 20 developed evidence of exhausted iron stores (transferrin %sat less than 16 or ferritin less than 30 micrograms/liter) before reaching target hemoglobin; two predicted to become deficient (projected deficit less than 100 mg) did not; and all five predicted to avoid iron deficiency (mean projected surplus 177 +/- 20 mg) remained iron replete. During acute rHuEPO therapy net body iron balance remained neutral in patients receiving no iron supplements and increased 5 mg/kg in patients prescribed oral ferrous sulfate. However, in patients given iron dextran i.v. less than 60% of elemental iron administered became measurable as iron stores or usable for hemoglobin synthesis.

Determination of pipothiazine in human plasma by reversed-phase high-performance liquid chromatography.

A method is described for the determination of pipothiazine in human plasma, based on reversed-phase HPLC. The method has been applied in a pharmacokinetic study of pipothiazine in six psychiatric patients receiving repeated depot intramuscular injections for six months. A number of compounds likely to be taken concurrently by patients were tested for potential to interfere with the assay. There was no evidence of "dose-dumping" in the period following injection. Comparison of the pharmacokinetic profiles after the first and sixth injections showed no evidence of drug accumulation.

Exertional heat stroke and acute renal failure in a young woman.

Strenuous exercise leading to heat stroke is known to cause rhabdomyolysis and acute renal failure in men, but there are no reports of this environmental illness in otherwise healthy women. We report the first case of heat and exercise induced acute renal failure in a young nonacclimated adult female following intense exertion in the Grand Canyon. This individual displayed the typical clinical features of exertional heat stroke including hyperpyrexia, CNS disturbance, rhabdomyolysis, oligoanuric acute renal failure, and disseminated intravascular coagulopathy. The pathophysiology is discussed as well as sexual differences in response to heat and exercise. The specific factors that may have predisposed this young woman to heat stroke from exertion are identified.

Continuous arteriovenous hemodiafiltration: an aggressive approach to the management of acute renal failure.

Continuous arteriovenous hemodiafiltration (CAVHD) offers a modified therapeutic approach to the patient with acute renal failure. The system employs a hollow-fiber dialyzer, whose perfusion is dependent on the patient's BP. Peritoneal dialysis solution is infused through the dialysate ports in a direction countercurrent to blood flow at a rate of 500 to 1,500 mL/h. Five complex patients with acute renal failure were treated with CAVHD for periods ranging from two to 40 days. Urea clearances approached 37 L/d, and in stable patients, the BUN was maintained at 40 to 60 mg/dL and serum creatinine 1.4 to 4.0 mg/dL. Ultrafiltration up to 1 L/h could be obtained without difficulty. CAVHD is a safe and technically simple procedure that is particularly suitable for hemodynamically unstable patients with ongoing needs for fluid removal.

Post-transplantation T cell lymphoblastic lymphoma.

Immunosuppressed renal transplant recipients are at increased risk for large cell lymphoma of B cell phenotype. This report describes a case of post-transplantation lymphoma presenting with a mediastinal mass causing superior vena cava syndrome, tracheal obstruction, and pleural effusion. Cytospin preparations of pleural fluid documented high-grade lymphoblastic lymphoma morphology and immature T cell (cortical thymocyte) phenotype: Leu 1-6-positive, Leu 9-positive, Tdt-positive, B-negative, Calla-positive. The occurrence of post-transplantation lymphoma of T cell lineage is inconsistent with the postulated Epstein-Barr virus origin and raises important questions regarding the development of lymphoproliferative disorders in immunosuppressed organ transplant recipients.

Immunosuppressive therapy and plasmapheresis in rapidly progressive glomerulonephritis associated with bacterial endocarditis.

A 25-year-old male presented with new cardiac murmurs and acute renal insufficiency. Blood cultures grew Streptococcus viridans and appropriate antibiotic therapy was initiated. A renal biopsy revealed diffuse proliferative glomerulonephritis with crescents involving more than 50% of the glomeruli. Treatment with antibiotics, plasmapheresis, and steroids resulted in renal recovery that paralleled reductions in circulating immune complexes. The rationale for this therapeutic approach is discussed, as well as a review of two similar case reports. These experiences suggest a possible role for plasmapheresis and immunosuppressive drugs in patients who develop rapidly progressive glomerulonephritis as a complication of bacterial endocarditis.

Dietary calcium deprivation and secondary hyperparathyroidism in patients treated with chronic dialysis.

In 33 patients with end-stage renal disease undergoing chronic dialysis, serum parathyroid hormone (PTH) levels were correlated with serum concentrations and dietary intakes of calcium and phosphate. The average dietary calcium intake (549 +/- 54 mg/24 h) was lower than the recommended dietary allowance. There was a weak correlation between serum PTH and serum calcium concentrations (r = 0.39, p less than 0.03). There was also a significant negative exponential relationship between dietary calcium intake and serum PTH (y = 162e-0.0016x, r = 0.61, p less than 0.002). Likewise, when divided into low calcium (less than 500, 304 +/- 27 mg/24 h) and modest calcium (greater than 500, 809 +/- 56 mg/24 h) intake groups, in the low calcium-intake group, serum PTH (128 +/- 20 pg/ml) was more than 2-fold greater than that in the modest calcium-intake group (53 +/- 8 pg/ml, p less than 0.003). These results suggest that low dietary calcium intake may contribute to the occurrence of secondary hyperparathyroidism in patients with chronic renal failure undergoing chronic dialysis.

Radiology of postnatal skeletal development. XIII. C1-C2 interrelationships.

Composites of C1 and C2 were analyzed in various roentgenographic projections to elucidate osseous interrelationships and the effect of overlap of different portions of these two vertebrae in standard radiographic projections during differing stages of postnatal chondro-osseous transformation. In anteroposterior projections the dentocentral synchrondroses of C2 normally was located below the inferior rim of the C1 anterior ossification center. The upper extent of the dens ossification center was behind this anterior C1 center. The overlap made visualization of the ossiculum terminale difficult. The spinous process of C1 could be confused with the ossiculum. In transverse projections, the normal laxity characteristic of young children allowed considerable variation in rotational interrelationships. Various degrees of such instability are illustrated. In lateral views variation of the anterior contour of the dens was significant. Such variation must be considered developmental due to the location and direction of growth of the chondrum terminale and interactive modeling between C1 and C2 to allow extension at this particular joint.

The anatomy of metaphyseal torus fractures.

On the basis of several human and animal specimens, torus (bone-expanding) fractures appear to be a combination of plastic deformation and complete fracture of the cortex in the transition area of woven-fibered metaphyseal bone to lamellar (osteon) diaphyseal bone. The cortex in this region of susceptibility undergoes an abrupt transition from relative porosity to increased density. The changes in the biomechanic characteristics in the transition region may predispose to local failure, while micro- and macrostructure dictate that the pattern of failure will be torus deformation rather than a complete transverse fracture.

Comparing vascular access methods.

Adequate AV access remains the key to long-term survival of patients having ESRD requiring maintenance hemodialysis. The standard AV fistula described by Brescia and Cimino remains the time proven preferred hemodialysis AV access. However, the overwhelming majority of ESRD patients have inadequate, absent, or thrombosed vasculature preventing surgical creation of the fistula bringing out the necessity for prosthetic grafts. The Bovine heterograft, although associated with increased primary thrombosis and a shorter duration of patency, does offer greater stimulation of fibroblastic ingrowth in some patients with predictable poor healing characteristics. The reinforced PTFE (Gore-Tex) graft for construction of a bridged AV fistula has proven to be a valuable, reliable prosthetic with a minimum complication rate and the longer duration of patency when used as AV access. The physical characteristics and physiological properties of Gore-Tex and Bovine grafts are reviewed in Table II.

Evaluation of potential renal donors and renal allograft recipients: digital video subtraction angiography.

Digital video subtraction angiography is a safe, easily performed, outpatient procedure that was applied to evaluating the arterial anatomy of 11 potential renal donors and 22 examinations of 19 renal allograft recipients. Digital intravenous angiography depicted the number and position of renal arteries preoperatively in renal donors and excluded renal arterial or parenchymal disease. It accurately defined transplant arterial stenoses and demonstrated the status of the intrarenal circulation. No morbidity nor decreased renal function resulted. Digital video subtraction angiography has become the procedure of choice for these referrals at this institution.

Coccidioidomycosis in renal replacement therapy.

The potential risk of coccidioidomycosis has led to concern about the advisability of maintaining renal transplantation programs in endemic areas. We reviewed the charts of 721 patients undergoing dialysis and 260 renal transplant recipients in Arizona to determine the incidence, risk factors, and clinical course of coccidioidomycosis in these immunosuppressed populations. Symptomatic infection occurred in six (0.83%) patients undergoing dialysis and 18 (6.9%) transplant recipients. Male sex and blood type B predisposed to dissemination. Urine cultures for fungus were important diagnosis aids. Four of six patients with infection limited to the thorax and five of 18 patients with dissemination remained alive after seven months to 7 1/2 years. Although the rate of dissemination (75%) and mortality (63%) from coccidioidomycosis were high, the incidence of infection was low and does not preclude renal transplantation in Arizona. Those who have received transplants elsewhere should be advised not to move or to visit areas endemic for coccidioidomycosis.

Skeletal metastasis: the effect on the immature skeleton.

The unique opportunity to study the entire appendicular skeleton of a child who died from metastatic angiosarcoma allowed detailed assessment of radiographically evident involvement. Virtually every portion of the appendicular skeleton had evidence of metastatic disease. However, the extent of involvement was extremely variable, especially when contralateral regions were assessed. The most likely region of metastasis, the metaphysis, is normally a fenestrated cortex of woven bone in the young child, rather than a well demarcated cortex formed by osteon (lamellar) bone, as it is in the adult. The pattern of destruction is such that less extensive areas may be involved before becoming radiographically evident, and trabecular bone involvement may be evident even without cortical damage. The metaphyseal metastatic spread supports the concept of arterial hematogenous dissemination, comparable to osteomyelitis in the child. Pathologic metaphyseal fractures involved both proximal humeri; the fracture also extended along a portion of the metaphyseal-physeal interface in one humerus. In one distal femur the physis readily separated from the metaphysis; this was a non-displaced type 1 growth mechanism injury.