Simultaneous separation and quantitation of the major bovine whey proteins including proteose peptone and caseinomacropeptide by reversed-phase high-performance liquid chromatography on polystyrene-divinylbenzene.

A precise, sensitive and reliable RP-HPLC method was developed to enable not only unequivocal determination of alpha-lactalbumin and beta-lactoglobulin in bovine whey samples, but also simultaneous measurement of proteose peptone, caseinomacropeptide, bovine serum albumin and immunoglobulin G. The optimised method on the Resource RPC column allowed separation of the proteins in 30 min and could be applied to the analysis of soluble proteins in a variety of commercial and laboratory whey products. Furthermore, some qualitative information on protein heterogeneity and quality could be derived from the RP-HPLC analyses with additional data available from on-line electrospray mass spectrometry. Within- and between-day repeatability over a wide range of concentrations was excellent (RSD< or =5%) for all proteins except immunoglobulin G and bovine serum albumin where RSD was 7-10%. Analysis of grouped data from whey protein concentrate and whey protein isolate samples gave a limit of detection of < or =0.3% powder mass and a limit of quantitation of < or =1.0% powder mass for all proteins except immunoglobulin G. Limits of detection and quantitation were 0.6% and 2.0%, respectively, for this protein. Quantitative data obtained by the RP-HPLC method compared very favourably with data obtained by alternative methods of whey protein analysis.

Comparison of capillary electrophoresis with traditional methods to analyse bovine whey proteins.

The separation of the four major whey proteins by sodium dodecyl sulphate (SDS)-capillary gel electrophoresis (CGE) is described. Whilst commercially purified whey proteins could be analysed using the recommended protocol, the more complex nature of an acid whey and a reconstituted whey protein concentrate (WPC) powder necessitated considerable refinement of the CGE sample buffer. Individual whey proteins in the acid whey and WPC samples were then also separated and quantitated using capillary zone electrophoresis, polyacrylamide gel electrophoresis (PAGE) and HPLC methods and the results were compared. The values obtained for alpha-lactalbumin (alpha-Lac) and beta-lactoglobulin (beta-Lg) were consistent throughout the various methods, although size-exclusion HPLC, SDS-PAGE and SDS-CGE could not separate the two beta-Lg variants or the glycosylated form of alpha-Lac from the beta-Lg. There was considerable variation in the values for the bovine serum albumin and immunoglobulin determined by the different methods and it was concluded that none of the methods could satisfactorily quantitate all four whey proteins.

Hemodynamic indicators of postthrombotic sequelae.

Single or repetitive episodes of lower-extremity venous thrombosis may result in venous obstruction, valvular incompetence, and the postthrombotic syndrome. Seventy-seven patients with ileofemoral deep venous thrombosis diagnosed with biplane phlebograms received routine anticoagulant therapy and follow-up with clinical and noninvasive vascular examinations (reflux photoplethysmography, Doppler ultrasonography, and venous outflow plethysmography). The results of the final visit (mean, 25 months; range, three to 50 months) revealed that 53 patients (69%) had evidence of edema and/or hyperpigmentation and five patients (6%) had ulceration. Doppler ultrasonography was 77% sensitive (41 of 53 patients) and 95% specific (41 of 43 patients) at identifying patients with postthrombotic sequelae. We conclude that noninvasive testing throughout the rehabilitative period following acute deep venous thrombosis will identify patients at risk for postthrombotic symptoms. This information may alert the clinician toward initiating elastic compressive therapy in hopes of prolonging a disease-free interval.

Traumatic pseudoaneurysm following blunt trauma.

Traumatic aneurysms of the superficial femoral (SFA) and superior medial geniculate artery (SMGA) demonstrated late expansion of previously well contained hematomas which were pulsatile and remarkable for the presence of bruits. Injury to the SFA resulted in a cool, pulseless distal extremity. Direct exploration of the pseudoaneurysm cavity following proximal and distal control of the main arterial segment resulted in optimal exposure and successful repair of the arterial defect. Blunt trauma may result in pseudoaneurysm formation. Persistent swelling at a focus of injury despite normal distal pulsation is an early indicator of major vascular injury.

Surgical management of necrotizing pancreatitis.

Necrotizing pancreatitis has a formidable mortality that may exceed 55% even when treated by surgical drainage. Standard surgical techniques for controlling pancreatic sepsis are often inadequate because the unique chronicity of pancreatitis results in persistent and ongoing inflammation and sloughing of necrotic retroperitoneal tissue that promotes further sepsis. Ten consecutive high-risk patients in whom standard surgical debridement and drainage had failed were treated with open packing of the pancreatic bed. This was followed by daily debridement dressing changes at the bedside in the surgical intensive care unit. Management of the open abdomen in the surgical intensive care unit using standard surgical techniques ensured optimum wound toilet, prevented recurrent intra-abdominal sepsis, was logistically acceptable, was well tolerated by critically ill patients, and allowed a higher salvage rate (80%) of high-risk patients than might otherwise be anticipated.

Shoulder harness traction for roentgenographic assessment of the cervical spine.

We evaluated the clinical usefulness of a new shoulder traction device to facilitate a rapid complete cervical spine examination in an uncooperative patient population with multiple trauma. Forty-eight patients were randomly designated to receive the shoulder traction device or the standard technique (manual traction on the patient's upper extremities). Patient groups were equivalent in mean coma scale scores, trauma scores, age, and incidence of cervical fracture. Male-female ratios differed between groups, yet were biased against the harness technique. Fewer roentgenograms (lateral view) were required to visualize adequately all cervical vertebrae when the harness device was utilized (mean roentgenograms per patient, 1.2 vs 2.6; P less than .01). Shoulder harness traction during roentgenographic evaluation of the cervical spine may be a useful method to promote visibility of the lower cervical vertebrae.

Free-floating iliofemoral thrombus. A risk of pulmonary embolism.

We retrospectively evaluated the risk of pulmonary embolism in hospitalized patients with venographically proved iliofemoral deep vein thrombosis (DVT). Venograms and clinical records of 78 patients with iliofemoral DVT were reviewed and the proximal intraluminal thrombus was characterized as free-floating (greater than 5-cm nonadherent segment) or occlusive (no free-floating elements). The incidence of pulmonary embolism confirmed by high-probability radioisotope ventilation-perfusion lung scanning within ten days following venography was 9% (7/78) and was associated with 60% (3/5) free-floating and 5.5% (4/73) occlusive phlebographic criteria (P less than .05). All patients who experienced pulmonary embolism were given therapeutic heparin treatment (partial thromboplastin time, more than twice the control value). The mean (+/- SD) time from the diagnosis of DVT to pulmonary embolism was 104 +/- 60 hours, and 120 +/- 71 hours for patients with free-floating and occlusive thrombi, respectively (P greater than .05). Patients with iliofemoral DVT that met free-floating criteria are at significant risk for pulmonary embolism, despite the administration of heparin.

Detection of renal artery stenosis: experimental and clinical analysis of velocity waveforms.

Mass screening of hypertensive patients by a noninvasive method could uncover the 10% of those cases where renal artery stenosis is the primary etiology. Treatment by transluminal angioplasty or surgery could replace a long-term medical regimen. To investigate an ultrasonic technique, normal velocity waveforms were obtained from the abdominal aorta, celiac artery and renal arteries in seven mongrel dogs using a 5 MHz, continuous-wave Doppler detector. Renal artery pressure gradients, volume flow rates and velocity recordings were subsequently made during induced proximal renal artery stenoses. The ratio of peak renal artery frequency to peak aortic frequency was 88% sensitive to stenoses of greater than 20 mm Hg pressure gradient, while the renal artery systolic frequency window was 79% sensitive to the same obstructions. Ninety-five hypertensive and vascular surgical patients were examined using a 3 MHz duplex scanner with 175 of the 190 (92%) renal arteries adequately detected (clear signal with high diastolic component). Analysis of velocity waveforms based on peak frequency, proximal to distal peak frequency changes, evidence of flow disturbances and associated bruit were compared to contrast arteriograms in 84 vessels. Of the 76 (90%) arteries adequately examined by duplex scanning, 59 of 61 (97%) with 0-59% diameter reduction, 10 of 12 (83%) with 60-99% diameter reduction and 1 of 3 (33%) occlusions were correctly identified. Velocity waveform analysis can accurately detect renal artery stenosis and may prove effective in mass screening of hypertensive patients for renovascular disease.

Noninvasive quantification of ambulatory venous hemodynamics during elastic compressive therapy.

Quantifying the hemodynamic results of elastic compression requires invasive and cumbersome techniques. Twenty lower extremities (normal, primary, acute and chronic post-thrombotic varicosities) were evaluated with quantitative photoplethysmography (PPG) prior and subsequent to initiating graded compression. The PPG transducer is placed against the stockings and the in vivo method of calibration is used to predict the results of compressive therapy on ambulatory venous pressure (AVP). (table see text) Noninvasive evaluation of patients with quantitative PPG techniques following compressive therapy may provide a better understanding of venous hemodynamics and a rational approach to selection of therapy.

Renal artery flow velocity analysis: a sensitive measure of experimental and clinical renovascular resistance.

Renal artery flow velocity analysis has recently been shown to be an indicator of renal parenchymal resistance. Noninvasive measurement of graded renovascular resistance is investigated with experimental models of canine gel microsphere embolization (n = 15), canine renal allografts (n = 4), and clinical renal allografts (n = 6). Intraoperative pulsed Doppler recordings were made on the canine renal artery simultaneous to pressure and flow measurements with sequentially increasing resistance. Transcutaneous echo-Doppler (Duplex) measurements were made on acute patient renal allografts following chemical estimation of renal function. Noninvasive prediction of renovascular resistance in the experimental canine gel microsphere and allograft models correlates with invasive recordings of volume flow (pressure nearly constant), r = 0.93 and r = 0.90, respectively. Duplex estimation of clinical renal allograft resistance and chemical prediction of renal function are similarly interdependent, r = 0.81. Directional arterial flow analysis may be a useful indicator of native and acute allograft renovascular resistance.

Noninvasive evaluation of renal artery stenosis and renovascular resistance. Experimental and clinical studies.

Doppler ultrasound was used to detect experimental and clinical renal artery stenosis (RAS) and increased renovascular resistance (RVR). Parameters assessing RAS included elevated systolic frequency and spectral broadening, while diastolic/systolic frequency ratios predicted elevated RVR. In canine models these parameters detected graded RAS before reduction in renal blood flow. Index values were 88% sensitive and 100% specific in identifying RAS with gradients greater than or equal to 25 mm Hg. Diastolic/systolic frequency correlated well with increased RVR induced by microsphere injections (p less than 0.05). Duplex scanning noninvasively detected bilateral renal artery velocity in 113 of 120 patients. Index values were 83% sensitive and 97% specific in identifying greater than or equal to 60% RAS in 86 vessels visualized by angiography. Estimated RVR was significantly higher in age-matched hypertensive and atherosclerotic patients than in controls (p less than 0.01). Ultrasound may be useful to screen patients for RAS and increased RVR.

Quantitative photoplethysmography in chronic venous insufficiency: a new method of noninvasive estimation of ambulatory venous pressure.

We estimated ambulatory venous pressure (AVP) noninvasively with a new technique of quantitative photoplethysmography (PPG). Postural changes of hydrostatic pressure permitted in vivo calibration of the PPG. We recorded quantitative PPG and AVP in 14 normal subjects and 14 patients with postthrombotic chronic venous insufficiency. The results were contrasted with qualitative PPG recordings on 41 consecutive patients with chronic venous insufficiency. All but one of the latter patients demonstrated a decrement in skin blood content with exercise of the calf muscle, and shortened recovery time ws the only significant indicator of venous disease. Quantitative PPG correlated closely with AVP with respect to both estimated drop in superficial venous pressure (r = 0.97, P less than 0.001) and recovery time (r = 0.98, P less than 0.001). PPG estimates of intravenous pressure in normal and postthrombosis patients, 42 +/- 10 and 62 +/- 18 mm Hg, respectively, agreed with AVP measurements, 39 +/- 9 and 61 +/- 18 mm Hg, respectively. Quantitative PPG may prove to be an accurate estimate of AVP in patients with suspected chronic venous insufficiency.

Giant condyloma acuminatum (Buschke-Lowenstein tumor) involving a pilonidal sinus: a case report and review of the literature.

Giant condyloma acuminatum or Buschke-Lowenstein tumor has been reported to involve many areas about the perineum. The majority of previous documentations have implicated the coronal sulcus, prepuce, and fossa navicularis of the penis as the most likely foci to support growth. Authors have contributed multiple cases of perianal and rectal involvement as well as rare reports of inguinal, bladder, and endocervix-low uterine segment tumors. A case of giant condyloma acuminatum involving a chronic pilonidal sinus overlying the sacrum is described. Wide surgical extirpation was found to be a curative means of management.