Renal cryosurgery: experimental evaluation of treatment parameters.

Objectives: Cryosurgery represents a minimally invasive alternative for the management of small or equivocal lesions of the kidney. We evaluated the relationship between ultrasonographic appearance and intrarenal temperatures and the effect of renal artery occlusion on the efficacy of the freezing process in a canine model.

Methods: Ten animals were treated with intraparenchymal cryoablative therapy with (n = 5) or without (n = 5) renal artery occlusion using a rapid freeze technique.

Purification, characterization, and amino acid sequence determination of acanthins, potent inhibitors of platelet aggregation from Acanthophis antarcticus (common death adder) venom.

Venom of Acanthophis antarcticus, a common death adder, exhibits potent antiplatelet effects. By a combination of gel-filtration, cation-exchange, and reversed-phase chromatographic methods, two inhibitors of platelet aggregation, named acanthin I and II, were purified to homogeneity as assessed by capillary electrophoresis and electrospray mass spectrometry. These isoforms exhibit the most potent antiplatelet activity known thus far, with IC50 values of 7 nM for acanthin I and 4 nM for acanthin II in human whole blood when collagen was used as an agonist, whereas with ADP the IC50 values were 10 and 12 nM, respectively.

Increased intra-abdominal pressure during pneumoperitoneum stimulates endothelin release in a canine model.

Prolonged pneumoperitoneum during laparoscopic surgery has been associated with oliguria in clinical experimental studies. Although the pathophysiology of this oliguria is thought to be renal parenchymal and venous compression, the role of the potent vasoconstrictor endothelin (ET) has not been studied. The purpose of this study was to investigate the effect of pneumoperitoneum on endothelin release and renal function in a canine model.

The relation between pump flow rate and pulsatility on cerebral hemodynamics during pediatric cardiopulmonary bypass.

Objectives: Neurologic impairment, at least partly ischemic in origin, has been reported in up to 25% of infants undergoing cardiopulmonary bypass, with or without circulatory arrest. Controversy continues about the effect of pump flow, pulsatile or nonpulsatile, on the brain and in particular on cerebral blood flow. This study examines the relationship between pump flow rate and cerebral hemodynamics during pulsatile and nonpulsatile cardiopulmonary bypass.

The relation between arterial oxygen tension and cerebral blood flow during cardiopulmonary bypass.

Objectives: Neurological impairment occurs in up to 25% of infants undergoing cardiopulmonary bypass with or without circulatory arrest. Potential causes include alterations in cerebral blood flow, hypoxia and embolisation. During cardiopulmonary bypass, arterial oxygen tension is maintained at levels which under normal conditions cause cerebral vasoconstriction; this is a potential mechanism for ischaemia.

Stöckert roller pump generated pulsatile flow: cerebral metabolic changes in adult cardiopulmonary bypass.

There is evidence that during cardiopulmonary bypass (CPB), pulsatile pump flow improves cerebral metabolism. This was a study to explore the effect of pulsatile versus nonpulsatile perfusion on cerebral lactate, pyruvate, glucose and beta-hydroxybutyrate using a Stöckert roller pump. We found no significant differences between the arterial-venous (A-V) differences of lactate, glucose and beta-hydroxybutyrate (p > 0.

Medical treatment of cystinuria: results of contemporary clinical practice.

Purpose: We determined the efficacy of a contemporary medical regimen for treatment of cystinuria.

Materials And Methods: A total of 16 patients with cystinuria was followed for 7 to 141 months (mean 78.1).

Functional outcome of thoracolumbar burst fractures managed with hyperextension casting or bracing and early mobilization.

Study Design: A retrospective study to review the results of unstable thoracolumbar burst fractures managed with casting or bracing and early ambulation in neurologically healthy patients.

Objectives: To determine the clinical outcome of patients with unstable burst fractures of the thoracolumbar spine treated without surgery, and to identify any variables that may adversely influence the final outcome.

Summary Of Background Data: The management of unstable fractures of the thoracolumbar spine as described by Bedbrook involves a period of recumbency for 6-8 weeks followed by gradual mobilization.

Characterization of a large chondroitin sulfate proteoglycan present in bovine collateral ligament.

Bovine collateral ligament synthesized a 35S-labeled large proteoglycan species which eluted with a Kav of approximately 0.27 on Sepharose CL-2B and contained only chondroitin sulfate chains with a molecular mass of approximately 32 kDa. Fluorography of the 35S-labeled core proteins derived from the large ligament proteoglycan revealed a broad range of molecular masses above approximately 200 kDa, which was of comparable size to the four major endogenous core protein bands derived from this proteoglycan detected with 5/6/3-B-3, an antibody directed against terminal unsaturated chondroitin-6-sulfate disaccharides.

Multifocal metachronous epidural abscesses of the spine. A case report.

Study Design: A retrospective case report of a patient who had a lumbar epidural abscess treated surgically who then developed a cervical epidural abscess that also required surgical treatment.

Objectives: To describe a patient in whom treatment of a single epidural abscess with surgery and antibiotics was not sufficient to eradicate the systemic infection.

Summary Of Background Data: Epidural abscesses are most commonly seen after invasive procedures that violate the epidural space.

Increased expression of CD44 in bovine articular chondrocytes by catabolic cellular mediators.

Bovine articular chondrocytes cultured in alginate beads were used to study the effect of catabolic cellular mediators on CD44 expression. Treatment with either the 29-kDa fragment of fibronectin or interleukin-1 alpha results in a time- and dose-dependent inhibition of proteoglycan synthesis as well as a stimulation in the expression of CD44 mRNA level as determined by semi-quantitative polymerase chain reaction following reverse transcription. No noticeable effect at 6 h was observed.

Surface-modified diamond nanoparticles as antigen delivery vehicles.

Recognition of antigens by immunocompetent cells involves interactions that are specific to the chemical sequence and conformation of the epitope (antigenic determinant). Adjuvants that are currently used to enhance immunity to antigens tend to either alter the antigen conformation through surface adsorption or shield potentially critical determinants, e.g.

Elbow osteoarthritis and a massive forearm cyst. A case report.

Despite exhaustive evaluation, a massive forearm cyst in a 74-year-old man with elbow osteoarthritis could not be diagnosed. The patient had total elbow arthroplasty, and the cyst did not recur postoperatively. Osteoarthritis presumably caused the huge, but noncommunicating, synovial forearm cyst.

Rapid, sensitive and efficient HPLC assays for HIV-1 proteinase.

The proteinase encoded by human immunodeficiency virus type 1 (HIV-1) cleaves peptide substrates of sequences derived from processing sites in HIV-1 gag-pol polypeptide. Based on this cleavage, assays that utilize HPLC to measure activity of HIV-1 proteinase are reported herein. In the assay first described, a baseline separation of unlabeled substrate and products is achieved with a run time of 10 min and UV detection.

Interstitial deletion of chromosome 10q23: a new case and review.

A new case of a deletion of 10q23 is described. Only two other deletions involving this region have been previously noted. A review of clinical features of these three children did not show a distinct pattern of dysmorphic features.

Inhibition of human leukocyte elastase by N-substituted peptides containing alpha,alpha-difluorostatone residues at P1.

A series of tripeptides which contain alpha,alpha-difluorostatone residues at P1-P1' and span the S3-S1' subsites have been shown to be potent inhibitors of human leukocyte elastase (HLE). The tripeptides described contain the nonproteinogenic achiral residue N-(2,3-dihydro-1H-inden-2-yl)glycine at the P2-position. This redidue has previously been shown in the case of HLE to be a good bioisosteric replacement for L-proline.

Instantaneous axis of rotation as a function of the three columns of the spine.

A knowledge of the rotatory motion of the vertebral bodies is needed to understand the normal biomechanical behavior of the spine. The aims of this investigation were 1) to define the instantaneous axis of rotation of the lumbar spine in rotation; and 2) to study the effect of the loss of the anulus, facet joints, and ligamentous structures on the location of the instantaneous axis of rotation. The instantaneous axis of rotation was found in 10 human cadaver thoracolumbar spines by the method of Reuleaux from superimposed serial photographs.

Intrachromosomal insertion of chromosome 7.

A direct intrachromosome insertion of chromosome 7 is described, and previous reports of intrachromosomal insertions are listed. All others were ascertained through a phenotypically abnormal proband. Ours is the first presenting with multiple pregnancy losses.

Effect of "missed" pills on oral contraceptive effectiveness.

Objective: The purpose of this study was to determine whether missing pills in an oral contraceptive (OC) cycle resulted in folliculogenesis and eventual ovulation.

Methods: Fifteen women selected from a population requesting tubal reanastomosis were randomized into three groups and issued pill packs missing four consecutive pills in specific sequences, as follows: group I, days 1-4; group II, days 3-6; and group III, days 6-9. Serum was drawn for assay of LH, FSH, estradiol (E2), and progesterone, and serial ovarian ultrasound examinations were done to study follicular development throughout the cycle at 4-day intervals.

Novel non-nucleoside inhibitors of HIV-1 reverse transcriptase. 2. Tricyclic pyridobenzoxazepinones and dibenzoxazepinones.

Dibenz[b,f][1,4]oxazepin-11(10H)-ones (III), pyrido[2,3-b][1,4]benzoxazepin-6(5H)-ones (IV), and pyrido[2,3-b]- [1,5]benzoxazepin-5(6H)-ones (V) were found to inhibit human immunodeficiency virus type 1 reverse transcriptase with IC50 values as low as 19 nM. A-ring substitution has a profound effect on activity, with appropriate substituents at the positions ortho and para to the lactam nitrogen providing dramatically enhanced potency. Substitution in the C-ring is generally neutral or detrimental to activity.

Inhibition of human leukocyte elastase (HLE) by N-substituted peptidyl trifluoromethyl ketones.

A series of tripeptides possessing trifluoromethyl or aryl ketone residues at P1 were prepared and evaluated both in vitro and in vivo as potential inhibitors of human leukocyte elastase (HLE). Tripeptides containing non naturally occurring N-substituted glycine residues at the P2-position have been demonstrated to be potent in vitro inhibitors of HLE, with IC50 values in the submicromolar range. Sterically demanding substituents on the P2-nitrogen have no detrimental effect on in vitro potency.

Total knee arthroplasty using the total condylar III knee prosthesis.

Twenty-seven total knee arthroplasties (TKAs) were performed in 24 patients using the total condylar III knee prosthesis (TCP III) and were evaluated clinically and radiographically with a mean follow-up period of 4 years. Eighteen were revision TKAs, and nine were primary knee arthroplasties. Evaluations were made using the Hospital for Special Surgery (HSS) knee scale as well as the Knee Society radiographic evaluation method.

The effect of the three columns of the spine on the instantaneous axis of rotation in flexion and extension.

Instrumentation designed for stabilization and correction of spinal deformities must limit the amount of motion in flexion and extension. In flexion or extension, the vertebral bodies move about a specific point called the instantaneous axis of rotation. The ability of the implant to limit this motion is a function of its relation to the axis of rotation of the spine.

Total knee arthroplasty in rheumatoid arthritis. A comparison of the polycentric and total condylar prostheses.

From 1971 to 1985, 393 total knee arthroplasties (TKAs) were performed in patients for rheumatoid arthritis. Of these, 112 used polycentric prostheses and 131 used total condylar prostheses. One hundred seven of the patients with polycentric prostheses and 102 of the patients with total condylar prostheses were followed for a minimum of two years (average, 61 and 55 months, respectively).

Self-arrangement of molybdenum particles into cubes.

An unusual distribution of particle sizes has been observed following the formation of molybdenum particles by argon ion sputtering. Many of the molybdenum particles produced by sputtering at the threshold pressure for particle formation in the vapor appear to be single crystalline cubes. There are two prominent peaks in the edge length distribution of the cubes, one centered at 4.