Six week safety study of 2% MK-927 administered twice daily to ocular hypertensive volunteers.

Ocular hypertensive patients were enrolled in a 6-week double-masked safety study of 2% MK-927 (27 patients), a topically active carbonic anhydrase inhibitor, administered bilaterally b.i.d.; 9 additional patients received 0.5% timolol as the control agent. Intraocular pressure (IOP) was measured weekly prior to a.m. drug administration; twelve hour diurnal curves were performed prestudy and at 3 and 6 weeks. The mean reduction of IOP prior to a.m. drug administration ranged from 1.2 +/- 4.4 mm Hg (SD) to 3.0 +/- 4.2 mm Hg with MK-927 and from 4.7 +/- 3.9 mm Hg to 8.8 +/- 0.6 mm Hg with timolol. Mean outflow facility measured tonographically prestudy and on days 33 to 42 four hours after a.m. drug administration was unchanged in both groups. Corneal sensitivity (Cochet-Bonnet), corneal thickness (ultrasound pachymetry), Schirmer tear testing, and extensive ophthalmologic and medical examinations, and hematologic studies were not substantially altered throughout the study. In this longest chronic administration study to date, MK-927 did not cause adverse ocular or systemic side effects.


Ocular hypotensive actions of serotonin antagonist-ketanserin analogs.

A series of ketanserin analogs were studied for their effects on intraocular pressure (IOP) recovery curve of rabbits infused with hypertonic saline. Eight out of 31 compounds tested showed a marked delay in IOP recovery indicating that they are potential antiglaucoma agents. Five out of eight compounds showed equal suppression of the IOP recovery curves of treated and contralateral eyes indicating that these compounds could be absorbed systemically to affect the IOP of the contralateral eye. There were three compounds (GC 679, GC 646, and GC 526) which showed more suppression of the IOP recovery curve of the treated eye than that of the contralateral eye, indicating that these drugs might act primarily at the local site to lower the IOP. Therefore, these three compounds could produce antiglaucoma actions with little systemic side effects, if any.


Quantitative determination of the melanin contents in ocular tissues from human blue and brown eyes.

This paper deals with our findings on the quantities of melanin in the tissues from blue and brown eyes. The amount of melanin in the iris, ciliary body and retinal pigment epithelium-choroid was separately determined. The results are expressed as the amount of melanin in mg tissue as well as the amount of melanin in the whole tissue. The results showed that there was no statistically significant difference between the melanin content of the iris in blue and brown eyes. However the ciliary body and retinal pigment epithelium-choroid from brown eyes had more melanin than the corresponding tissues from blue eyes. Blue and brown eyes with higher colour intensity had more melanin than the corresponding eyes with lesser intensity of colour. It is suggested that the differences between brown and blue eyes in their melanin content may have relevance to the pharmacokinetics of drugs that bind to melanin. This would mean that the larger amounts of melanin would decrease the initial levels of the drugs and would increase the drug levels after prolonged periods.


The efficacy of aldose reductase inhibitors on polyol accumulation in human lens and retinal pigment epithelium in tissue culture.

The formation of excess sugar alcohol mediated by aldose reductase (AR) and its intracellular accumulation in lens with resultant hydration is thought to be the initiating mechanism in the pathogenesis of diabetic and galactosemic cataracts. AR is also involved in other diabetic complications including retinopathy and neuropathy. Therefore, there is heightened interest in developing effective AR inhibitors (ARIs) for possible clinical use in human diabetes. However, the evaluation of these drugs for potential clinical use requires that the compounds be evaluated in appropriate target tissues since AR from different tissues is known to exhibit differential susceptibility to ARIs. The relative efficacy of ARIs in human lens epithelium (HLE) and human retinal pigment epithelium (HRPE) was studied by measuring the degree of inhibition of galactitol formation at various concentrations of ARI following incubation of cells in high galactose media for 72 hrs. Regardless of the structural characteristics of the ARIs investigated, higher doses were required to inhibit polyol synthesis in HRPE as compared to HLE cells. Based on ED50 values, dose required for 50% inhibition, the order of potencies against both HLE and HRPE enzymes was AL-4114 greater than AL-3152 greater than AL-1576 greater than tolrestat greater than statil greater than sorbinil. Since some ARIs are known to be bound to plasma proteins, it is conceivable that the observed differences in ED50 values could be due to differential binding to serum proteins in the culture medium. This possibility was examined by employing cultures of dog lens epithelium (DLE). These cells, which synthesize much higher levels of galactitol than HLE and HRPE, could be maintained in serum-free media for short periods (4 hrs) of time. The results, which demonstrate that the extent of polyol inhibition was the same in the presence or absence of serum, suggest that the differences in the potency of the inhibitors may reflect their inherent activity against AR in HLE and HRPE cells.


The effect of some macromolecular ionic complexes on the pharmacokinetics and -dynamics of ocular cyclopentolate in rabbits.

The effect of mucoadhesive polymeric vehicles on the mydriatic efficacy, and on the systemic and ocular absorption of cyclopentolate from eyedrops was studied in albino rabbits. Combining cyclopentolate base to polygalacturonic (CY-PGA) or hyaluronic (CY-HA) acid resulted in an increased mydriatic effect when compared with cyclopentolate hydrochloride (CY-HCl). During the first half an hour, the systemic absorption of cyclopentolate was lower after CY-PGA than after CY-HCl. The ocular penetration of cyclopentolate, based on drug concentrations in aqueous humor 30 minutes after the eyedrop instillation, was increased 3 fold when the polygalacturonate complex was used. CY-PGA, as well as other polymeric salts, might offer a possibility to increase the therapeutic index of cyclopentolate.


Leukotrienes and sensory innervation in blood-aqueous barrier disruption in the dog.

The effect of a specific 5-lipoxygenase inhibitor, PF5901 (5% in corn oil), on disruption of the blood-aqueous barrier (BAB) in the dog was investigated using a unilateral mild paracentesis model. BAB breakdown was quantitated using anterior chamber fluorophotometry. Fluorescence in the eyes of the PF5901 group was not statistically significantly different (P greater than 0.05) from that in the vehicle group. A tendency towards greater fluorescein concentrations was noted in the PF5901 treated eyes. It was concluded that leukotrienes are not important mediators of BAB disruption in this model and that leukotriene inhibitors may actually exacerbate disruption due to shunting of arachidonate metabolism towards the cyclooxygenase and/or epoxygenase pathways. In a second experiment, the effects of proparacaine and flurbiprofen were evaluated on blood-aqueous barrier disruption and pupil size following a more severe paracentesis. Flurbiprofen dampened both barrier disruption and the miotic response but proparacaine suppressed neither reaction, suggesting that, in the dog, prostaglandins are more important mediators of the ocular irritative response than are sensory neuropeptides.


FGF promotes corneal stromal fibroblast motility.

It is well-known that growth factors accelerate wound healing by stimulating mitosis. Growth factors may also directly stimulate the motility of individual cells. We employed two different experimental methods to determine if fibroblast growth factor (FGF) enhances the individual motility of corneal stromal fibroblasts (independent of mitogenic effects). The effects of FGF on the motility of tissue-cultured rabbit corneal stromal fibroblasts were investigated in a modified Boyden chamber and by the agarose drop motility assay. Both assays showed a significant enhancement of stromal fibroblast motility by FGF at 100 ng/ml. It appears, therefore, that FGF may promote corneal stromal wound healing not only by increased cellular proliferation, but also by increased cellular motility.


The effects of transferrin receptor antibody, transferrin receptor antibody bound to Pseudomonas exotoxin and transforming growth factor-alpha bound to Pseudomonas exotoxin on human tenon's capsule fibroblast proliferation.

Pharmacological agents which modulate the wound healing process by the inhibition of proliferation of fibroblasts may improve the success of glaucoma filtration surgery. Since cell proliferation is essential to the wound healing process, we targeted the surface receptors that are associated with proliferating cells. We present the effects of three such agents-purified mouse anti-human transferrin receptor monoclonal antibody 42/6 (anti-TfR-42/6), anti-transferrin monoclonal antibody bound to a Pseudomonas exotoxin (anti-TfR-PE40) and transforming growth factor-alpha Pseudomonas exotoxin (TGF-alpha-PE40)--on human fibroblasts from Tenon's capsule. The inhibition of human subconjunctival fibroblast proliferation by anti-TfR-42/6 (with a concentration up to 25 micrograms/ml) and by anti-TfR-PE40 and TGF-alpha-PE40 (both with a concentration range of 5000-0.00001 micrograms/ml) was determined by colorimetric (OD), and cell counting (CC) assays over a 9-day period. Neither anti-TfR-42/6 nor anti-TfR-PE40 had an antiproliferative effect on the fibroblasts. TGF-alpha-PE40 demonstrated an antiproliferative effect in a dose response manner. The mean 50% inhibitory dose (ID50) by OD was 32.91 micrograms/ml, while the ID50 by CC was 27.88 micrograms/ml. EGF was used as a negative control for TGF-alpha-PE40 toxin. The inhibitory effect of the toxin conjugate was completely blocked by the addition of 1000 micrograms/ml of EGF. These in vitro studies show that TGF-alpha-PE40 may be useful in modulating the proliferation of human ocular fibroblasts; they also give some indication of drug dosages for future in vivo testing.


Knowledge-based decision support for patient monitoring in cardioanesthesia.

An approach to generating 'intelligent alarms' is presented that aggregates many information items, i.e. measured vital signs, recent medications, etc., into state variables that more directly reflect the patient's physiological state. Based on these state variables the described decision support system AES-2 also provides therapy recommendations. The assessment of the state variables and the generation of therapeutic advice follow a knowledge-based approach. Aspects of uncertainty, e.g. a gradual transition between 'normal' and 'below normal', are considered applying a fuzzy set approach. Special emphasis is laid on the ergonomic design of the user interface, which is based on color graphics and finger touch input on the screen. Certain simulation techniques considerably support the design process of AES-2 as is demonstrated with a typical example from cardioanesthesia.


A parallel implementation of a multi-state Kalman filtering algorithm to detect ECG arrhythmias.

Detecting arrhythmias from the electrocardiogram (ECG) is of great importance for the continued development of intelligent cardiovascular monitors (ICM). An ICM's main goal is to present to the clinician a 'high-level' analysis of the patient's condition (e.g., the patient is slightly hypovolemic) based upon 'low-level' physiologic signals (e.g., blood pressure, heart rate, etc.). This paper reports on a parallel implementation of a multi-state Kalman filtering algorithm, within a prototype ICM, to help detect ECG arrhythmias. Preliminary test results show that the parallel, multi-state implementation performed exactly as the original sequential version. Several different rhythm disturbances were correctly identified after 3-5 beats. We conclude that our parallel implementation of the multi-state Kalman filter provides a faster and still reliable means of accurately detecting ECG arrhythmias in real-time.


CASSPERT--an expert system to guide choice and strategy in coronary angioplasty.

Coronary angioplasty is a technique widely used in the treatment of coronary artery disease. The success of coronary angioplasty depends on patient selection, the use of an appropriate technique, and to a large extent a carefully considered choice of angioplasty equipment. The authors have developed an expert system which can assist in this decision making process. CASSPERT was developed using the expert system shell 'Leonardo' running on a standard Personal Computer. The user interacts with CASSPERT to build up a detailed profile of clinical, investigational and angiographic features of the patient. This information, together with technical data stored within Leonardo's own object orientated database, is used to infer a suitable choice of equipment. To make the expert system useful in clinical practise, it was interfaced within a functional, readily accessible, data acquisition and storage environment which could be used within the day to day running of the department.


Proposal of a computerized algorithm for continuous wave CO2 laser on-line control during orthopaedic surgery. Phase I: theoretical introduction and first in vitro trials.

New data obtained from treating polymethylmethacrylate (PMMA) with a non-moving cw- 10 watt-CO2 laser-beam focused at 2.5'', 5'', 7.5'' and 15.75'' are presented. . The final equations R(tc) and Z(tc) for each focal length are proposed. A very interesting correlation between the focal lengths in use and the integrated values of R and Z between 0 and 2 sec has been identified and discussed. This result has been used as basis to define a convenient operative protocol to follow during the planning phase of critical osteotomies or bone cement removal operations using a continuous-wave CO2 laser-beam set to any output power and focused by a set of most common, moving or non-moving focal lengths placed on the operating area. With a simple equation, it is possible to compare craters obtained with moving and non-moving laser-beams at different operative conditions between 0 and 2 sec, time interval which covers the majority of cases. A value of 2.3 +/- 0.1 between ablated volumes of PMMA and bone tissue has been identified. Several case studies regarding orthopaedic procedures from Literature are here reported and compared to the present LCA model. The computerized on-line flow of information for the laser-beam optimization and safety control is also described. Finally, a method for the simultaneous data collection from several operating rooms via a Local Area Network (LAN-Industry Standard IEEE) onto a central data base for later consultation is proposed in its general design.


Clinical evaluation--continuous real-time intra-arterial blood gas monitoring during anesthesia and surgery by fiber optic sensor.

A clinical evaluation of the clinical utility, techniques of use, durability, accuracy, and potential complications of a newly available system for the continuous real-time, intra-arterial monitoring of arterial blood gas and acid base status (ABG) has been studied (Optex BioSentry System, Optex Biomedical, Incorporated, The Woodlands, Texas, U.S.A.). The system consists of three separate fiber optic channels with contained fluorescent and absorbant chemical analytes imbedded in a single probe and capable of insertion inside of a twenty gauge indwelling arterial catheter (The Optex Optode Sensor), along with an external monitor. The system was utilized during anesthesia and surgery in the care of five informed patients. Constant trend monitoring of all three variables was deemed satisfactory in four of the patients. The fifth sensor was damaged by a surgical assistant while in place and ceased to function. Comparison of Optode sensor readings with standard clinical laboratory ABG analysis was excellent in three uncomplicated patients (pH: bias -0.0183 pH units, precision: 0.0237 pH units; PCO2: bias 3.22 mmHg, precision 2.04 mmHg; PO2: bias -5.94 mmHg, precision 11.74 mmHg). Postoperative study suggested that discrepancies in a fourth patient may have been due to an incorrect 'offset' applied to the Optode sensor yielding a constant error.


INFORM: European survey of computers in intensive care units.

The aims of this study were (a) to survey and evaluate the impact of information technology applications in High Dependency Environments (HDEs) on organizational, psychological and cost-effectiveness factors, (b) to contribute information and design requirements to the other workpackages in the INFORM Project, and (c) to develop useful evaluation methodologies. The evaluation methodologies used were: questionnaires, case studies, objective findings (keystroke) and literature search and review. Six questionnaires were devised covering organizational impact, cost-benefit impact and perceived advantages and disadvantages of computerized systems in HDE (psychological impact). The general conclusion was that while existing systems have been generally well received, they are not yet designed in such a developed and integrated way as to yield their full potential. Greater user involvement in design and implementation and more emphasis on training emerged as strong requirements. Lack of reliability leading to parallel charting was a major problem with the existing systems. It proved difficult to assess cost effectiveness due to a lack of detailed accounting costs; however, it appeared that in the short term, computerisation in HDEs tended to increase costs. It is felt that through a better stock control and better decision making, costs may be reduced in the longer run and effectiveness increased; more detailed longitudinal studies appear to be needed on this subject.


Ultra slow wave pressure variations in the anal canal before and after lateral internal sphincterotomy.

Ultra slow waves (USW's) in the anal canal are discrete pressure fluctuations with a low frequency (1-2/minute) and high amplitude (> or = 10% above or below baseline resting pressure). To investigate the nature of these USW's, anorectal manometry was performed in 20 control subjects as well as in 58 patients presenting with anal fissure or symptomatic hemorrhoids, before and 2 weeks after lateral internal sphincterotomy. USW's could be demonstrated in two control subjects and in 29 patients. The median value of maximum anal resting pressure (MARP) in the two control subjects with USW's was significantly higher than the median MARP in the 18 control subjects without USW's (181.5 vs. 92 cm H2O, p < 0.001, two-tailed Mann-Whitney test). The same difference was found between MARP in patients with and without USW's (158 vs. 138 cm H2O, p < 0.05, two-tailed Mann-Whitney test). All patients were treated by means of lateral internal sphincterotomy (LIS). Two weeks after this procedure USW's had disappeared in half of the patients. The MARP in these patients was reduced to a level found in control subjects without USW's. This pressure reduction was significantly greater than in patients with persistent USW's (40% vs. 15%, p < 0.02, two-tailed Mann-Whitney test). Because USW's are associated with high MARP and disappear when such a high anal canal resting pressure is reduced by LIS to a level found in control subjects without USW's, it can be concluded that USW's are the manifestation of increased activity of the internal anal sphincter.


The failing pelvic pouch conversion to continent ileostomy.

Excision of a failing pelvic pouch is often a great disappointment for the patient. It is also an unfortunate decision considering that a significant length of terminal ileum is sacrificed. Transformation of the pouch to a continent ileostomy is an alternative. Five patients with a malfunctioning pelvic pouch have had their pouch converted to a continent ileostomy. The operative technique is described.


Induction chemotherapy with carboplatin and 5-fluorouracil in combination with radiotherapy in loco-regionally advanced epidermoid carcinoma of the anus--preliminary results.

During the last decade conservative treatment of anal carcinoma based on radiotherapy has gained popularity. Radiotherapy is often combined with concurrent chemotherapy although no firm evidence exists that such combinations are more effective than radiotherapy alone. Treatment results with respect to anal sphincter function are generally better for small tumors. In an effort to improve the treatment results for locally advanced epidermoid anal carcinoma, a selection of patients with such tumors has been treated with induction chemotherapy comprising two or three courses of a combination of carboplatin 300-350 mg/m2 i.v. and 5-fluorouracil 1,000 mg/(m2 x d) x 5 d prior to radiotherapy. Six female patients aged 37 to 74 have completed the regimen. All had complete tumor regressions at conclusion of radiotherapy. No recurrence has yet occurred but the follow-up period is still short (8-21 months). No interruption of chemotherapy due to toxic side effects was necessary and no severe toxicity registered. Further study is needed to evaluate the efficacy and toxicity of the regimen, but these early findings are promising.


The stapled functional end-to-end anastomosis following colonic resection.

To determine the results of our experience with the use of staples for construction of anastomoses following colonic resection, a series of 223 anastomoses performed in 205 patients was reviewed. Indications for operation included malignancy, benign neoplasms, inflammatory bowel disease, and several miscellaneous entities. A functional end-to-end anastomosis using the standard GIA cartridge and the TA 55 instruments was performed. The operative mortality was 1.5% with none of the deaths related to the anastomosis. Intraoperative complications encountered included bleeding (21), leak (1), tissue fracture (1), instrument failure (4), and technical error (3). Early postoperative complications related or potentially related to the anastomosis included bleeding (5), pelvic abscess (1), fistula (1), peritonitis (2), ischemia of anastomosis (1). Late complications included five patients with small bowel obstruction, two of whom required operation. Anastomotic recurrences developed in 5.9% of patients. Our experience gained with stapling instruments has shown them to be a reliable method for performing anastomoses in the colon in a safe and expeditious manner.


Successful local repair of paracolostomy hernia with a newly developed prosthetic device.

The basic cause of paracolostomy hernia is enlargement of the trephine opening in the abdominal wall, due to tangential forces working on the circumference of the opening. Our attempts of hernia repair with polypropylene mesh were not successful, as the diameter of the hole in the mesh tended to enlarge with time. For this reason we developed a new device, which secures the desired diameter of the opening. The prosthesis consists of a polypropylene ring with an internal diameter of 20, 25 or 30 mm, mounted in the centre of a polypropylene mesh. In 14 patients with a parastomal hernia, complicating an end colostomy, this prosthesis has been used. In one patient the implant had to be removed owing to infection. In the remaining 13 patients no recurrence or other complications have been noted after a median follow-up of 18 months (range 5-35 months). We conclude that the presented prosthetic device seems to be a useful adjunct for the local repair of a paracolostomy hernia.


Pelvic recurrence after surgical treatment of rectal and sigmoid cancer. A prospective clinical trial on 274 patients.

The aim of this collaborative prospective study was to verify the incidence of pelvic recurrence (PR) after radical surgery for cancer of the rectum and sigmoid. Very low anterior resection (VLAR) was usually performed, with the aim of preserving anal function and obtaining the maximum of radicality by means of en bloc excision of the mesorectum. Between 1984 and 1987, 274 patients underwent curative surgery for rectal and sigmoid cancer, 230 (84%) of whom underwent anterior resection (AR) and 44 (16%) abdominoperineal resection (APR). Post-operative mortality was 2.5%. Follow-up ranged from 24 to 72 months (mean 37 m); 248 cases (90.5%) were included in the final prospective study. PR occurred in 41/248 cases (16%), within 24 months in 80% of cases. PR occurred in 15.8% (33/208) after AR and in 20% (8/40) after APR, p = NS. Nevertheless in middle and low rectal tumours at stage C the incidence of PR in patients who had VLAR was 34.5% (10/29) and 12% (3/25) in those who had APR (p < 0.05). PR rates in VLAR patients was 40% for stage C low rectal tumours and 54.5% for low rectal tumours at Astler Coller stage C2. The PR incidence for stage C1 tumours of the low rectum was zero after VLAR and APR, allowing the assumption that lymphnode metastases in non-penetrating tumours do not compromise the results when the mesorectum is completely excised. We can assume that the choice of VLAR as a substitute for APR whenever possible limits the comparison of their results.(ABSTRACT TRUNCATED AT 250 WORDS)


Early postoperative contrast radiology in the assessment of colorectal anastomotic integrity.

The predictive value and safety of early postoperative radiological assessment of colorectal anastomotic integrity is controversial. In this study, 233 patients with colorectal or left sided colonic anastomoses had water soluble contrast enemas performed in the early postoperative period (mean: day 7 postoperatively, range: days 4-14). A total of 40 radiological leaks were recorded but only 12 of these patients had clinical signs of anastomotic dehiscence. Furthermore, 11 patients who had normal contrast enemas subsequently developed a clinical anastomotic leak. There were therefore 28 (12.0%) false positive and 11 (4.7%) false negative results giving values for the specificity and sensitivity of the radiological investigation of 86.7% and 52.2% respectively. Only 3 patients (1.3%) developed a clinically apparent anastomotic complication following a contrast enema. We conclude that while radiological assessment of distal large bowel anastomoses in the early postoperative period appears to be a safe procedure, it provides little useful clinical information with regard to early postoperative morbidity. Recent work has, however, suggested that radiological anastomotic integrity may be relevant to long term outcome following surgery for colorectal cancer.


Primary adenosquamous and squamous cell carcinoma of the colon and rectum.

Three new cases of squamous cell and adenosquamous carcinoma of the rectum are reported, bringing the total number of cases in the English medical literature to 72. Each of the three patients presented with painless hematochezia. Therapy was by surgical resection followed by chemoradiation therapy in two patients. The incidence, presentation, diagnostic criteria and methods, tumor location, natural history, theory of etiology and management of this unusual tumor are discussed.


Sodium and potassium excretion before and after conversion from conventional to reservoir ileostomy.

Sodium and potassium in the ileostomy output and urine were determined in 28 patients with ulcerative colitis on a free diet and in eight patients on a defined constant diet, before and after conversion from a conventional ileostomy (CI) to a continent reservoir ileostomy (RI). Feces and urine were collected both in the hospital and at home. Patients with CI on free diet had a median intestinal loss of 62 mmol sodium and those with RI 74 mmol/24 h collected in the hospital (p < 0.05). The figures for at home was 79 and 81 mmol/24 respectively, and were larger than in the hospital (p < 0.01). Sodium loss in the urine (U-Na) and the intake of sodium did not change significantly after conversion. Patients with a low U-Na before conversion also had a low U-Na after, in a few almost nil, implying a need for increased intake of sodium. Patients with a CI and low urinary output of sodium should be carefully studied with respect to their sodium balance before accepting them for conversion to RI. The ileostomy output of potassium increased after conversion (4.3 vs. 6.8 mmol/24 h; p < 0.01) in the hospital (5.3 vs 7.1 mmol/24 h; p < 0.01) at home. Patients on a defined constant diet before and after conversion did not show any significant differences in absorption of sodium, potassium, magnesium or calcium after conversion, but did show a reduced dry weight of the ileostomy output, indicating an increased degradation of intestinal contents in RI patients.(ABSTRACT TRUNCATED AT 250 WORDS)


Radioimmuno-guided endoscopy (RIGE) in the detection of primary and recurrent rectal tumor.

The usefulness of radioimmunoguided endoscopy in the detection of primary and recurrent rectal cancer was investigated. Of the 15 patients included in our study, 4 with suspected primary rectal cancer were examined preoperatively, while the remaining 11 were studied after radical resection of rectal carcinoma with the aim of detecting local recurrence. Radioimmunoguided endoscopy was performed employing a hand-held gamma-detecting probe (mod. 2 Oris, France), after the administration of a 111In labeled monoclonal antibody to CEA. Radioimmuno-guided endoscopy results detected the presence of primary or recurrent periluminal cancer in seven cases. In four it modified the preoperative stage based on the findings of conventional investigation and it influenced the surgical decision in five cases. No toxicity was noted and none of the patients developed HAMAs.


The internal anal sphincter can not close the anal canal completely.

We determined the maximum closing capability of the internal anal sphincter muscle ring in vitro and in vivo. The internal sphincter, 4 to 6 mm thick, cannot close the anal canal hermetically, not even during maximal contraction. The blood-filled anal cushions have to fill up an intrasphincteric gap of at least 7 to 8 mm in diameter.


The value of endosonography in preoperative staging of rectal cancer.

Sixty-three patients with mobile rectal cancer were examined preoperatively with endorectal ultrasonography (EUS). The depth of infiltration and the presence of mesorectal lymph node metastases could be assessed in 53 patients. Doppler ultrasonography was performed in 16 cases with suspected lymph node enlargement in order to discriminate between lymph nodes and blood vessels. Tumour growth in the bowel wall was correctly estimated in 43 (81%) patients. The degree of spread was overestimated in five patients and underestimated in five. The evaluation of the mesorectal lymph node status was also accurate in 43 (81%) patients. Nine patients had one or several regional lymph node metastases, but the EUS revealed only some of the metastatic lymph nodes in each case. In the other 34, no lymph node metastases were found. In two patients the EUS was falsely positive since no lymph nodes could be demonstrated in the operative specimens. In eight patients the examination was falsely negative. EUS is considered to be an accurate method for preoperative assessment of tumour infiltration in the bowel wall as the risk of understaging was under 10%. Preoperative irradiation and surgery may be chosen based on the EUS-determined tumour extension into the rectal wall.


Renal metastases from papillary thyroid carcinoma.

Papillary thyroid carcinoma is the most common type of thyroid cancer. It is estimated that 4% to 20% of patients with papillary carcinoma will develop distant metastases during the course of their disease, most commonly to lung and bones. We describe the rare occurrence of metastatic papillary carcinoma of the thyroid to the kidney in a living patient that was successfully treated with a right radical nephrectomy and 131I with complete disappearance of all metastatic disease.


Reducing potential liability in evaluation of the breast.

One in nine women will develop breast cancer in her lifetime. It is crucial to evaluate the breast with a three-part approach: self breast examination, annual physician breast examinations, and mammography. In addition, and of equal importance, is proper documentation of the findings and communication between the physicians involved.


Experience with a new woven prosthesis.

The search for the ideal vascular graft is a dream that has eluded surgeons for centuries. Since the introduction of the fabric vascular prosthesis in 1952 by Voorhees, Jaretzki, and Blakemore, a wide variety of materials and designs have been tested. Dacron has withstood the test of time in both the knitted and woven types. Each of these graft designs has its own advantages and disadvantages, but we believe that the interlock construction of the Ochsner series grafts provides a solution to the problems associated with the earlier woven grafts while maintaining the advantages of the woven construction: (1) unraveling has been eliminated, and fraying has been reduced by the use of the interlock stitch; (2) the graft has been made soft and pliable by using three low-twist yarns, avoiding chemical impaction of the yarns, and utilizing a loose crimp; and (3) nonfixation of the pseudo-intima has been corrected by using low-twist, highly filamentous yarns which allow ingrowth of tissue for good fixation.


Molecular mechanisms of thrombin-induced human and bovine endothelial cell activation.

Thrombin, the key regulatory protein of hemostasis, is a potent stimulus for endothelial cell activation, a process implicated in a variety of ischemic, thrombotic, and inflammatory vascular disorders. Activation of the thrombin receptor requires a novel mechanism of receptor proteolysis generating a tethered receptor ligand. Synthetic peptides whose sequences are identical to this newly exposed receptor NH2-terminus reproduce thrombin effects on human and bovine endothelial cell activation. Receptor cleavage by catalytically active alpha-thrombin is tightly coupled to a PI-PLC, with resultant generation of IP3 and DAG, increases in [Ca2+]i, and translocation of PKC (Fig. 3). Both the increase in [Ca2+]i and PKC activation are required for thrombin-stimulated PLA2 and PLD activity, PGI2 synthesis, and barrier dysfunction, the latter occurring as the result of Ca2+ and PKC effects on specific cytoskeletal protein elements and other contractile proteins (Fig. 3). Further investigations are ongoing to identify more clearly not only the precise biochemical intermediates involved in the endothelial cell response to thrombin but also the specific protein kinase systems involved in thrombin-mediated signal transduction in vascular endothelium.


Sickle erythrocyte adherence to large vessel and microvascular endothelium under physiologic flow is qualitatively different.

Complications in sickle syndromes are thought to result from regional disturbances of normal blood flow with subsequent ischemic damage. Adherence of sickle erythrocytes has been implicated in the pathophysiology of occlusive complications. Most previous studies have explored adherence of sickle erythrocytes to endothelial cells from large vessels, even though the majority of the pathophysiologic models implicate the microvascular system. To explore potential variation in endothelial interactions at low shear rates, adherence of sickle erythrocytes to large vessel umbilical vein endothelium and microvascular endothelium was compared under flow conditions in a parallel-plate flow chamber at a shear stress of 1.0 dyne/cm2. Autologous plasma promotes high levels of sickle red cell adherence to microvascular endothelial cells, but only low levels of adherence to human umbilical vein endothelium. On average, autologous plasma promotes sixfold more sickle cell red adherence to microvascular endothelial cells. In contrast to umbilical vein endothelium, high molecular von Willebrand factor does not elevate sickle cell adherence to microvascular endothelial cells, and the integrin receptor agonist peptide, RGD, does not inhibit adherence to microvascular endothelial cells. These results demonstrate that sickle erythrocyte adherence to large vessel and microvascular endothelium is quantitatively and qualitatively different and that plasma factors may have significant impact on sickle erythrocyte adherence to endothelium in the microvessels. Since microvascular occlusion has been suggested as an antecedent of ischemic damage in sickle syndromes, plasma enhanced adherence to microvascular endothelium may contribute to the pathophysiology of episodic occlusion in sickle cell anemia.


Pigs with von Willebrand disease may be resistant to experimental infective endocarditis.

Indirect evidence suggests that the blood platelet is important in the pathogenesis of experimental infective endocarditis. Mechanical injury to the endocardial surface causes deposition of fibrin and platelets; injected microorganisms quickly localize to this lesion. Endocarditis pathogens also bind to and activate platelets. We used our previously described animal model for inducing infective endocarditis in normal pigs and applied it to animals with severe von Willebrand disease. The model uses catheter-induced trauma to the aortic valve and endocardium, followed by intravenous injection of group C streptococci. Control animals all showed typical clinical and laboratory evidence of endocarditis. In contrast, in pigs with von Willebrand disease (n = 4) endocarditis failed to develop. Studies in vitro of platelet-bacteria interactions showed that platelets derived from both normal and diseased pigs were equal in their ability to bind to and be activated by group C streptococci. These data suggest that normal platelet function is important in the pathogenesis of experimental infective endocarditis.


Monoclonal antibody to tumor necrosis factor--alpha prevents lethal endotoxin sepsis in adult rhesus monkeys.

In a rhesus monkey endotoxin sepsis model established by intravenous administration of 300 mg/kg D-galactosamine and 0.1 microgram/kg lipopolysaccharide from Salmonella abortus equi, hemodynamic, respiratory, metabolic and hematologic variables; levels of blood gases; monkey leukocyte elastase levels, and blood plasma concentrations of tumor necrosis factor--alpha (TNF) were monitored for 6 hours after administration, and again after 24 hours. Thirty minutes after administration of lipopolysaccharide, either 15 mg/kg anti-TNF monoclonal antibody (MoAB; n = 6) or vehicle placebo (saline solution; n = 4) were given intravenously. During this short-term experiment the organ functions were not different between the treatment groups. However, anti-TNF MoAb afforded morphologic protection from heart, lung, liver, and kidney damage after lipopolysaccharide challenge. Coagulation responses (platelet count and levels of fibrinogen, antithrombin III, and thrombin-antithrombin III complex) were smaller in anti-TNF MoAB-treated monkeys. Plasma TNF levels (WEHI cell cytotoxicity assay) reached a peak (350 pg/ml) 60 minutes after lipopolysaccharide administration in vehicle control subjects but no TNF was detected in the anti-TNF MoAB-treated monkeys. All control animals died 67 +/- 30 hours after lipopolysaccharide administration from multiorgan failure. On the contrary, all anti-TNF MoAB-treated animals survived 14 days (p > 0.005 vs placebo group mortality). Thus in short-term monkey experiments our study indicates protection against lipopolysaccharide-induced endotoxin sepsis by anti-TNF MoAB, which may have clinical relevance for the treatment of human septicemia.


Phosphorus 31-nuclear magnetic resonance spectroscopy of rat liver during simple storage or continuous hypothermic perfusion.

The adenosine triphosphate (ATP) content and intracellular pH (pHi) of isolated rat liver before, during, and after cold preservation in either University of Wisconsin lactobionate solution (UW) (n = 10) or Euro-Collins solution (EC), (n = 8) were monitored with phosphorus 31 nuclear magnetic resonance. The 31P nuclear magnetic resonance spectra were obtained on a 4.7 T system operating at 81 MHz. Fructose metabolism, liver enzyme release, oxygen consumption, and rat survival after liver transplantation were also evaluated. During simple cold storage (SCS) the ATP level declined to undetectable levels with both preservation solutions whereas the pHi declined to approximately 7.0. In contrast, during continuous hypothermic perfusion (CHP), hepatic ATP levels remained measurable during the 24-hour EC preservation and actually increased significantly (p > 0.01) during UW preservation. After reperfusion at 37 degrees C with Krebs lactate, the livers in SCS treated with EC differed significantly from the UW-treated livers in terms of their ATP level and pHi and their response to a fructose challenge. In contrast, livers undergoing CHP demonstrated similar behaviors with both solutions. These results demonstrate an increase in the hepatic ATP content during CHP, which occurs with UW but is not seen with EC. On the other hand, only livers that were simply stored with UW achieved significant survival after transplantation, whereas CHP livers were affected by vascular damage as demonstrated by fatal thrombosis after transplantation. These data suggest that ATP content is not the only determinant of good liver function. A system of hypothermic perfusion might further improve liver preservation efficacy should injury to the vascular endothelium be avoided.


Cardiac anaphylaxis in the Sprague-Dawley rat.

Anaphylactic shock was induced in pentobarbital-anesthetized, mechanically ventilated Sprague-Dawley rats that had been sensitized 21 days earlier to crystallized ovalbumin. The sensitization was confirmed by passive cutaneous anaphylaxis test. Antigen challenge produced an immediate reduction in mean aortic pressure from 168 to 67 mm Hg within 1 minute after intravenous injection of ovalbumin. Plasma histamine increased from 4.5 to 128 ng/ml within 5 minutes after injection of antigen. There were no changes in airway or esophageal pressures after antigen challenge. Left ventricular diastolic pressure was increased, and contractility, as measured by the rate of change of left ventricular pressure (dP/dt), was decreased over an interval exceeding 90 minutes. When isolated, constant flow--perfused hearts from sensitized Sprague-Dawley rats were challenged with antigen, decreases in left ventricular function were observed associated with decreased positive and negative maximum rate of change of left ventricular pressure (dP/dtmax). This experimental model in the rat therefore demonstrated selective myocardial impairment with reduced inotropism and lusitropism after anaphylaxis.


Identification of two zinc metalloendopeptidases in alveolar macrophages of rats, guinea pigs, and human beings.

Neutral endopeptidases EC 3.4.24.11 and EC 3.4.24.15, widely distributed zinc metalloendopeptidases, degrade a number of biologically active peptides including substance P, bradykinin, neurotensin, and luteinizing hormone-releasing hormone. In this study we measured EC 3.4.24.11 and EC 3.4.24.15 activity in alveolar macrophages, key inflammatory cells in the lung that produce and respond to a large number of bioactive substances including chemotactic peptides, with the substrates glutaryl-ala-ala-phe-2-naphthylamide and tertiary butoxycarbonyl-phe-ala-ala-phe-paraaminobenzoate, respectively. We found that specific activity of EC 3.4.24.15, defined as activity inhibited with N-[(1RS)-carboxy-3-phenylpropyl]-ala-ala-phe-paraaminobenzoate+ ++, was significantly higher (p < 0.001) in cells from Sprague-Dawley rats (485 +/- 123 nmol/mg protein.hr) than in cells from Hartley guinea pigs (138 +/- 94 nmol/mg protein.hr), healthy human male smokers (121 +/- 73 nmol/mg protein.hr) and healthy human male nonsmokers (94 +/- 12). In contrast, activity of EC 3.4.24.11, defined as activity inhibited with N-[(1RS)-carboxy-3-phenylpropyl]-phe-paraaminobenzoate, was significantly higher (p < 0.001) in cells from human smokers (689 +/- 167 nmol/mg protein.hr) and nonsmokers (762 +/- 136 nmol/mg protein.hr) than in cells from rats (52 +/- 12 nmol/mg protein.hr) and guinea pigs (34 +/- 14 nmol/mg protein.hr). An additional activity in alveolar macrophages toward tertiary butorycarbonyl-phe-ala-ala-phe-paraaminobenzoate was inhibited with L-3-carboxy-trans-2,3-epoxypropionyl-leucylamido-(4-guanido) butane, a specific inhibitor of cysteine proteinases, a finding of interest because in general enzymes in this class show little activity at neutral pH.(ABSTRACT TRUNCATED AT 250 WORDS)


In vivo studies of biliary ceftriaxone excretion and solubility in guinea pig hepatic bile.

Ceftriaxone (CFTX), a third-generation cephalosporin, has occasionally been reported to produce biliary sludge composed of its calcium salt. We performed studies in guinea pigs to (1) investigate the hepatic route of CFTX excretion, (2) determine ceftriaione's effects on bile flow and composition, and (3) quantify the solubility and metastability of the calcium salt as a function of administered dose. Our results show that even at high doses ceftriaxone has only minimal effects on bile flow and biliary electrolyte secretion, either alone or in combination with bile salt (taurocholate) infusion. A significant increase in total calcium concentration was observed without change in free Ca2+ concentration, this is compatible with formation of a soluble calcium salt of ceftriaxone, as previously demonstrated in vitro. Ion products of Ca2+ and ceftriaxone as high as 3.5 times the solubility product constant without crystal formation were observed, confirming the presence of a metastable state for the calcium salt of ceftriaxone in the living animal. Biliary excretion of ceftriaxone inhibited excretion of indocyanine green, suggesting that ceftriaxone and indocyanine green share a common anionic excretory pathway in this species.


Distribution of erythrocyte free porphyrin content in erythropoietic protoporphyria.

Erythrocytes of patients suffering from erythropoietic protoporphyria (EPP) contain high levels of unchelated protoporphyrin IX (PP) molecules when they enter circulation, and the leakage of PP that leaks from the circulating cells is responsible for the patients' cutaneous photosensitivity. The level of PP in EPP blood has long been used as an indicator of the severity of the disease and is useful in its management. The present study investigates what additional information may be obtained by determining the distribution of the PP content of individual EPP red cells. Absorption and fluorescence images of fields of the dispersed and immobilized red cells from nine patients with EPP were acquired under computer control by use of an inverted fluorescence microscope equipped with a cooled slow-scan charge-coupled device camera. The distribution functions of the fluorescence emitted by individual red blood cells (IRBC) were derived by a suitable image analysis program and were converted to the distributions of the cellular PP content by relating the average value of the distributions (Iav) to the PP level of packed cells, as determined by an extraction assay. The IRBC distributions show that a small percentage of the red cells is responsible for most of the PP fluorescence, and the distributions of IRBC/Iav for the nine patients with EPP were found to be very similar. This is consistent with the leakage rate during circulation being approximately proportional to the cells' PP content.


Urinary calcium excretion in essential hypertension.

Patients with essential hypertension have been reported to have higher levels of urinary calcium excretion (UCaV) than normotensive persons. We tested the hypothesis that the calciuria of hypertension is due to dietary factors and evaluated several alternate mechanisms. UCaV was studied in 15 patients with essential hypertension compared with 16 age- and gender-matched normotensive control subjects. For subjects taking self-selected, free-living diets, the difference in UCaV between normotensive (130 +/- 14 mg/day) and hypertensive subjects (201 +/- 37 mg/day) was not significant (p = 0.1). However, in a controlled diet with moderately restricted sodium intake (88 mEq), urinary calcium excretion was significantly higher (p = 0.02) in the hypertensive than in the normotensive group receiving 400 mg calcium (204 +/- 25 vs 132 +/- 13 mg/day) and 1400 mg calcium (272 +/- 31 vs 187 +/- 25 mg/day). Twenty-four-hour UCaV was directly and significantly correlated with blood pressure (r = 0.63 for standing systolic blood pressure; p < 0.001). A 1000 mg oral calcium load caused similar changes in UCaV (0.12 +/- 0.11 vs 0.12 +/- 0.07 mg per 100 ml glomerular filtration) and serum ionized calcium level (0.06 +/- 0.08 vs 0.06 +/- 0.02 mmol/L) in normotensive and hypertensive subjects, respectively, suggesting that there was no difference in intestinal calcium absorption between the groups. Fasting UCaV did not differ between the hypertensive (8.9 +/- 4.5 mg per 2 hours) and normotensive groups (10.9 +/- 11.5 mg per 2 hours).(ABSTRACT TRUNCATED AT 250 WORDS)


Cirrhosis impairs serum bacteriostasis for Escherichia coli.

To study the effects of cirrhosis on serum inhibition of Escherichia coli, cirrhosis with ascites was induced in male Sprague-Dawley rats by intragastric administration of carbon tetrachloride. Heat-inactivated (56 degrees C for 30 minutes) serum from cirrhotic rats (CRS) or that from control rats (NRS) was inoculated with 1 x 10(5) colony-forming units per milliliter (CFU/ml) of E. coli, and growth was measured after 24 hours. The mean growth of E. coli in CRS was significantly higher than growth in NRS: 3.5 +/- 5.4 x 10(8) CFU/ml versus 1.2 +/- 2.0 x 10(6) CFU/ml, respectively (p < 0.01). Fifty-four percent of CRS samples (22/41) completely lacked bacteriostatic activity. These CRS samples were categorized as growth-supporting (G+CRS) because their growth exceeded the mean + 2 SD of NRS (5.2 x 10(6) CFU/ml). Serum bacteriostasis could be restored to G+CRS by adding purified rat apotransferrin (1 mg/ml), suggesting the presence of excess iron in G+CRS. However, serum iron concentration (SI) and total iron binding capacity (TIBC) were virtually the same in G+CRS (SI = 120 +/- 22 micrograms/dl; TIBC = 351 +/- 45 micrograms/dl) as in growth-inhibitory CRS (SI = 131 +/- 16 micrograms/dl; TIBC = 347 +/- 46 micrograms/dl) but were significantly less than NRS (SI = 208 +/- 29 micrograms/dl; TIBC = 533 +/- 57 micrograms/dl), p < 0.01. The percent transferrin saturation was similar in all groups: 34% +/- 6%; 38% +/- 5% and 39% +/- 9%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)


Bone response to invading tumors with spindle cell components: a report of findings in two patients.

Two case studies are presented in which quantitative bone histomorphometry is used to analyze bone changes in adult patients with diagnosed spindle cell sarcoma. Three tumor-involved sites and one noninvolved site from the iliac crest of patient 1 were evaluated. In the involved sites the percentage trabecular bone volume (11.0%) and the number of osteoblasts (0.6 cell/mm2) were significantly reduced, osteoid volume was significantly increased (8.1%), and woven osteoid was present. The total eroded surface (6.8%) was also significantly increased. In the noninvolved site the number of osteoblasts was decreased and both the percentage eroded and percentage osteoclast surfaces were increased. In the femoral epicondyle specimen from patient 2 the number of osteoblasts was 27.0 cells/mm2, percentage osteoid volume was 18.4%, percentage osteoid surface was 62.9%, and osteoid thickness was 20.0 microns. In tumor-involved sites in both patients indices of active bone resorption were similar and normal. These two case studies indicate that (1) distinctive morphologic changes occur in bone invaded by spindle cell sarcoma, and that (2) changes affect bone formation to a greater extent than bone resorption. Bone alterations are probably local in nature and related to the extent and duration of tumor invasion and the influence of local tumor factor(s).


Inhibitory effect of platelet factor 4 (PF4) on the growth of human erythroleukemia cells: proposed mechanism of action of PF4.

The effect of platelet factor 4 (PF4) on the growth of human erythroleukemia cell line (HEL) and the binding characteristics of iodine 125-labeled PF4 to cells were studied to determine the mechanism of action of PF4. HEL cells were cocultured with various doses of PF4 in either a plasma clot system for colony assay or a liquid system for tritiated thymidine incorporation. A significant inhibition of HEL colony growth and tritiated thymidine incorporation was seen at PF4 doses of 1 microgram/ml and 0.5 microgram/ml, respectively. The inhibitory effect of PF4 could be abrogated by the addition of heparin (5 to 10 micrograms/ml). Enzyme-linked immunosorbent assay showed that PF4 had no obvious effect on the expression of platelet glycoprotein IIb/IIIa of HEL cells. Binding of 125I-PF4 to HEL cells reached equilibrium within 20 to 30 minutes with dissociation constant of 1.3 x 10(-10)M and Bmax of 6.3 pmol/10(5) cells and was inhibited by an excess of unlabeled PF4, beta TG, and heparin but was not affected by PMA, IL-3, IL-6, GM-CSF, and interferon-alpha. PF4 did not affect the binding of 125I-IL-3 and 125I-IL-6 to HEL cells. These data demonstrate that PF4 inhibits the growth of HEL cells by specific binding to HEL cells and suggest that the action of PF4 may be associated with the heparin-binding sites of the molecule.


Blood pressure changes in patients with chronic obstructive pulmonary disease and hypertension completing phase II pulmonary rehabilitation.

A retrospective study was conducted evaluating the resting blood pressure (BP) of 160 patients at the onset and upon successful completion of a Phase II pulmonary rehabilitation program. Patients with chronic obstructive pulmonary disease (COPD) exercise at submaximal loads. Patients with both hypertension and COPD would remain hypertensive after a course of pulmonary rehabilitation. The two-tailed t-test was utilized to compare BP at the onset to BP at the completion of the program. No significant differences were found in the following groups: (1) Start and end SBP or DBP of all patients; (2) Start and end SBP or DBP of the 40 (25%) hypertensive patients (HTN-Pts); (3) Start and end SBP or DBP of the 6 (4%) HTN-Pts on antihypertensive (anti-HTN) medications; (4) Start and end SBP or DBP of the 34 (21%) HTN-Pts off anti-HTN medications. This study supports the hypothesis that HTN-Pts with COPD participating in a Phase II pulmonary rehab program remain hypertensive. Hypertension in this population should be treated medically.


Treatment of traumatic pancreatic pseudocyst by percutaneous aspiration.

We describe the nonoperative management of a traumatic pancreatic pseudocyst following blunt trauma in a child. This problem can be accurately diagnosed and followed with computed tomography or ultrasound. Percutaneous aspiration of unilocular pancreatic pseudocysts in children provides an attractive alternative to operative treatment in selected cases.


Bronchoscopy for pulmonary hygiene in the intensive care unit.

The safety and ease of fiberoptic bronchoscopy recommends its use in the intensive care unit. In critically ill patients, the procedure may be a valuable diagnostic or therapeutic tool. In most instances, the diagnostic indications are well defined. The therapeutic indications for bronchoscopy, however, are more controversial. They center around using the bronchoscope for removal of secretions, mucus plugs and reversing atelectasis in mechanically ventilated patients. This report examines the small but definite risk of therapeutic bronchoscopy in mechanically ventilated patients.


Long-term results of total ossicular chain reconstruction using autografts.

The long-term results of 63 total ossicular chain reconstructions using autografts is presented. The follow-up period ranged from 18 months to 18 years with an average of 8.5 years. The primary aims of the study were firstly to assess the long-term success rate and to find out if there were any hitherto unknown causes of bone graft failure. In the event, it was found that the recently described anatomical variation of the oval window viz., the deep oval window, was the prime cause of failure in 32 per cent of unsuccessful cases. Some measures to help to mitigate this problem, are suggested. The result were assessed on the basis of: 1. A minimum gain of 20 dB HL in air conduction (Technical success). The success rate was 55.5 per cent. 2. Patients benefited using Smyth and Patterson's criteria in conjunction with the Glasgow Benefit Plot; 54 per cent of the patients benefited significantly.


Nasal polypectomy: should antral washout be a routine?

Seventy patients with nasal polyps were studied. Forty-seven of these had pre-operative sinus radiographs and all seventy patients had antral washouts at the time of nasal polypectomy. One hundred and seventeen antral aspirates were sent for culture and microscopy. The naked eye appearance of aspirates were turbid in 34 patients. Bacteria were cultured from 15 of the specimens in 10 patients. It was concluded that antral washout should be recommended in all patients who have nasal polypectomy and that there is no need for sinus radiographs in those patients who have uncomplicated nasal polyps.


Antroscopy in rhinoscleroma.

Rhinoscleroma is a chronic specific granulomatous inflammatory condition that has an affinity to the mucosa of the upper respiratory tract. Involvement of maxillary antrum is said to be very uncommon. In the present study antroscopy was performed in 20 patients with rhinoscleroma to find out the type, nature and site of the lesion in the maxillary antrum. The maxillary antrum was involved in 60 per cent of cases with rhinoscleroma. The lesions occurred in the form of atrophic changes, granuloma, and the fibrotic thick healed stage. The anterior-inferior part and medial wall of the antrum are found to be more commonly affected. It is suggested that involvement of maxillary antrum in scleroma may act as a reservoir of infection and such patients may therefore take a longer time to respond to antibiotic therapy.


Treatment of allergic and vasomotor rhinitis by the local application of different concentrations of silver nitrate.

In 1980, Bhargava et al. reported a new treatment of allergic and vasomotor rhinitis by the local application of 15 per cent silver nitrate. The results of further studies of the treatment by using different concentrations of silver nitrate ranging from 5 per cent to 25 per cent and normal saline as placebo are presented here; 15 per cent has been found to be the most effective concentration giving successful results in 75.7 per cent of cases. It is applied to the anterior portion of both inferior turbinates and the anterior part of the nasal septum once a week on five occasions. Best relief was obtained from the most annoying symptoms of sneezing and rhinorrhoea. Asthma was controlled in 50 per cent of such patients who had attacks of allergic rhinitis followed by asthma. For this widely prevalent disease, the treatment was found to be simple, easy and useful, with negligible side-effects.


Radiological and endoscopic study of the maxillary sinus in primary atrophic rhinitis.

The maxillary sinuses of 40 patients suffering from primary atrophic rhinitis (ozaena) were studied radiologically, antroscopically and histopathologically. Sixty per cent of the patients showed thick bony walls and a small cavity of the maxillary sinus on X-ray and on antroscopy. On the other hand, 25 per cent of the cases revealed signs of infection including mucopurulent secretion on antroscopy associated with corresponding histopathological changes. It is concluded that poor pneumatization of the antrum plays a more important role in the pathogenesis of ozaena than infection.


Is injectable collagen truly safe?

Most patients have no response to injectable collagen or silicone, but some cases may have positive or 'undersea' (= clinically negative but immunologically positive) response to collagen. From the results of the Macrophage migration inhibition test, the relative immunogenicity was augmented most when we used implants with the following combination. The first immunization was collagen and the second one was collagen with silicone. The augmented antigenicity might be enough to cause an allergic reaction to the patients who had no response to each implant alone.


Flexible nasopharyngoscopy for fish bone removal from the pharynx.

The use of flexible nasopharyngoscopy with biopsy forceps for the removal of fish bones found in the oropharynx and hypopharynx is described. One hundred and sixty-eight patients with ingested fish bones in the upper aero-digestive tract were studied over a 12-month period. Of these, 73 per cent were removed per-orally, or by indirect laryngoscopy. Fifteen per cent were removed using the fibreoptic nasopharyngoscope. Twelve per cent required a general anaesthetic and rigid oesophagoscopy for removal of fish bones at or below the level of the cricopharyngeus muscle. The technique has proven to be quick, well tolerated and low in morbidity. It is invaluable in patients in whom indirect laryngoscopy is unsatisfactory.


Few surgical complications after 5,000 to 6,500 cGy pre-operative irradiation for carcinoma of the tongue.

Twenty-four patients with squamous cell carcinoma of the tongue were treated with 5,000 cGy to 6,500 cGy pre-operative irradiation. Surgery usually consisted of resection of the tongue, possibly the floor of mouth, and modified or radical neck dissection. Musculocutaneous flaps for reconstruction were used in three cases and a forearm flap in one case. Despite the high radiation dose, no major difficulties were encountered at surgery or during the convalescence period, except for one osteoradionecrosis of the mandible, which was successfully treated by microvascular osteomyocutaneous grafting. Residual carcinoma was seen on histological examination of the excised tissue in 9 out of 18 (50 per cent) patients who received > or = 6,000 cGy, and in 4 out of 6 (67 per cent) patients who received about 5,000 cGy tumour dose. The 2-year crude survival rate was 65 per cent. The data suggest that high dose pre-operative irradiation is feasible and does not compromise surgical treatment.


Complications of treatment of recurrent laryngeal papillomatosis with the carbon dioxide laser in children.

A retrospective study of the complications of treatment with the carbon dioxide (CO2) laser of 17 patients diagnosed to be suffering from recurrent laryngeal papillomatosis is presented. No immediate complications occurred except one case of laryngospasm and failure to intubate during anaesthesia leading to hypoxic encephalopathy. Three patients were completely free from disease and complications. Another patient was free from laryngeal lesions but developed a papilloma in the right tonsillar pillar. Five other patients showed one or more multiple sites of involvement in addition to the larynx. Laryngeal scarring developed in ten patients. Six patients (35.29 per cent) developed scarring as anterior glottic webs while in two scarring (11.7 per cent) occurred as posterior glottic webs. One developed scarring in the supraglottic region. The remaining one had scarring in both the glottic and supraglottic regions. One patient developed tracheal scarring necessitating laryngo-tracheal separation. Two patients were psychologically disturbed during treatment requiring psychiatric consultation and therapy.


The open access ENT casualty service.

The ENT specialist's experience of emergencies is usually influenced by a process of prior selection in the GP surgery or in a general Casualty Department. A survey of 1,000 consecutive patients presenting to a 24 hour open access ENT Casualty service is presented. For a variety of reasons, over half of these patients had never sought their G.P.'s advice for their ENT complaint but preferred the hospital service. The value of even a brief exposure to ENT casualty work for GP trainees is demonstrated.


Difficult diagnostic laryngoscopy and bronchoscopy aided by the laryngeal mask airway.

A case of difficult diagnostic rigid bronchoscopy is described. However, flexible fibrescopy could be easily performed through a laryngeal mask airway despite complete lack of experience by the operator. Excellent visualization of the larynx and bronchial tree with minimal haemodynamic disturbance accompanied the technique.


Tracheostomy self care: the Nottingham System.

Tracheostomy self care at home can be a problem for some patients. The Nottingham System attributes a competence ratio to each patient. Those liable to develop problems can be identified early and the appropriate support provided. The Nottingham System is described.


Darier's disease of the external ear.

Darier's disease is a hereditary dermatological condition characterized by crusted papules distributed over the seborrhoeic areas of the trunk and head. A case of Darier's disease presenting to the Otolaryngology department because of severe involvement of the pinna is reported. The typical histological appearances are described and treatment discussed.


Maxillary sinus fusariosis in immunocompetent hosts.

We report the first known cases of Fusariosis of maxillary sinus with granuloma and oro-antral fistula in two immunocompetent hosts. Fusarium solani was demonstrated in the direct microscopic examination and isolated in heavy growth from the biopsy materials. Both these patients were successfully treated with oral ketoconazole (200 mg daily) for three weeks followed by a Caldwell-Luc operation. Ketoconazole was continued for two months post-operatively.


Acute stridor due to bilateral vocal fold paralysis as a presenting sign of myasthenia gravis.

We describe a case of myasthenia gravis in a 46-year-old man presenting as acute stridor with bilateral abductor paralysis of the vocal folds. Prompt diagnosis and medical treatment with pyridostigmine avoided the need for tracheostomy. It is important to remember the possibility of myasthenia gravis in cases of stridor due to bilateral vocal fold paralysis, since effective medical treatment is available.


Tracheal reconstruction using a composite microvascular temporoparietal fascia flap and nasal septal graft.

The successful repair of a crushed cervical trachea using a composite microvascular graft is presented. The patient has been without a tracheostomy for four years.


Management of acute dilatation of the oesophagus presenting as stridor.

Acute dilatation of the oesophagus causing stridor is rare. A case is presented and the literature is reviewed with emphasis on the management of this problem.


Ectopic thyroid mass adherent to the oesophagus.

A 51-year-old female presented with a sensation of a lump in the throat for five months. Clinical examination was normal. The barium swallow and the CT scan showed a well-defined mass to the left of the upper oesophagus and behind it. The mass was removed surgically and shown pathologically to be a nodule of ectopic thyroid tissue. This very rare pathology is discussed together with a review of the relevant literature.


Malignant parotid salivary gland peripheral nerve sheath tumour in a twelve-year-old girl.

A case of a malignant parotid salivary gland nerve sheath tumour is reported in a 12-year-old girl who developed a right parotid mass. Initial incisional biopsy showed a tumour with a mesenchymal spindle cell appearance. Immunohistochemical studies showed positive staining of tumour cells for vimentin and focally for S-100 protein. These features together with ultrastructural evidence of basal lamina material suggested that the tumour was of nerve sheath origin. After subtotal parotidectomy the tumour metastasised to cervical lymph node and lung. There was evidence of a partial response to chemotherapy. A detailed illustrated histopathological description of the tumour is given.


Management of an unusual presentation of foreign body aspiration.

Foreign body aspiration is a very common problem in children and toddlers and still a serious and sometimes fatal condition. We are reporting on a 2-year-old white asthmatic male who choked on a chick pea and presented with subcutaneous emphysema, and on chest X-ray with an isolated pneumomediastinum but not pneumothorax. On review of the literature an isolated pneumomediastinum without pneumothorax was rarely reported. This presented a challenge in management mainly because of the technique that we had to use in order to undergo bronchoscopy and removal of the foreign body. Apnoeic diffusion oxygenation was used initially while the foreign body was removed piecemeal, and afterwards intermittent positive pressure ventilation was used. The child did very well, and his subcutaneous emphysema and pneumomediastinum remarkably improved immediately post surgery.


Bilateral internal jugular phlebectasia.

Internal jugular phlebectasia is a venous anomaly commonly presenting as a unilateral neck swelling in children. The clinicopathology, aetiology and management are discussed. Bilateral doppler ultrasonography is the diagnostic investigation of choice and should be performed in all suspected cases. Conservative management of the bilateral case is recommended.


Promoting access, accommodations, and independence for college students with learning disabilities.

This article focuses on the four primary issues that directly affect service delivery to students with learning disabilities in postsecondary settings, including (a) How are high school and post-secondary settings different? (b) How are eligibility and access determined? (c) How are reasonable accommodations determined? and (d) How can the independence level of college students with learning disabilities be fostered? Each of these issues will be discussed within the context of the student's transition from high school, where Public Law 94-142 is in effect, to college, where Section 504 of the Rehabilitation Act of 1973 applies.


The success of college students with learning disabilities: factors related to educational attainment.

This study reports on the educational attainment of 62 college students with learning disabilities as compared to a sample of 58 peers matched on gender and ACT composite score (+/- 1 point or exact match). All students were native English speakers and were enrolled as degree candidates in a small, competitive, private, midwestern college. Groups were compared on age, high school preparation and performance, college grades, GPA at the end of each year of study, graduation and academic failure rate, and time taken to complete degree. Factors that may have influenced outcomes are discussed as are implications for college admissions officers, college students with learning disabilities, service providers, and academic advisors.


Learning disabilities and vocational rehabilitation.

Students with learning disabilities have received services in special education programs for many years. Unfortunately, many of these students continue to need services after they exit high schools. Vocational rehabilitation has begun to provide services for young adults with learning disabilities; however, there continues to be a discrepancy between the number of adults with learning disabilities who need vocational rehabilitation services and those who are receiving them. This article describes the definitions and eligibility criteria used by vocational rehabilitation agencies to serve adults with learning disabilities. By understanding the vocational rehabilitation system, teachers, it is hoped, will be better able to access these services for their students with learning disabilities.


The postschool adjustment of persons with learning disabilities: current status and future projections.

Recent research on the adult status of individuals with learning disabilities was reviewed. It was found that learning disabilities persist into adulthood, that manifestations of learning disabilities in adulthood are different than in childhood, and that many adults with learning disabilities are not independent or self-sufficient. These findings are related to the changes American society is currently undergoing, particularly changes in the workplace. Implications for teachers are discussed.


Enhancement of murine macrophage binding of and response to bacterial lipopolysaccharide (LPS) by LPS-binding protein.

We have studied the effects of highly purified rabbit lipopolysaccharide (LPS)-binding protein (LBP) on the ability of murine bone marrow-derived macrophages to respond to bacterial LPS. Macrophage responses studied include the secretion of tumor necrosis factor alpha, production of arginine-derived nitrite (NO2-), and killing of an intracellular pathogen, Leishmania enriettii. Macrophages from either CBA or LPS-hyporesponsive C3H/HeJ mice exhibited significantly greater sensitivity to LPS in the presence of LBP. Furthermore, both CBA and C3H/HeJ macrophages demonstrated an LBP-dependent enhancement of LPS binding. These results suggest that C3H/HeJ macrophages are capable of binding LPS-LBP complexes and support the hypothesis that hyporesponsiveness in this strain involves a step subsequent to LPS binding. Furthermore, these findings provide additional evidence of the important role played by the acute-phase plasma protein LBP in modifying host response to LPS.


Autonomy and competence as motivational factors in students with learning disabilities and emotional handicaps.

Over 450 students (136 elementary, 321 junior and senior high school) with primary handicapping codes of learning disability (LD) or emotional handicap (EH) completed several questionnaires. All participants were from self-contained classrooms of a state-operated special education system. Questionnaires assessed students' self-perceptions and perceptions of home and classroom contexts, with all variables theoretically reflecting either the competence or the autonomy aspects of internal motivation or students' personal adjustment. Math and reading standardized achievement test scores were obtained from school records. Using multiple regression analyses, students' achievement and adjustment were predicted from the motivationally relevant self-perception and perception-of-context variables. Interestingly, different patterns of relations emerged for the students with LD and EH.


Treatment of murine macrophages with interferon-gamma inhibits their ability to bind leishmania promastigotes.

The binding of leishmania promastigotes to macrophages pretreated with interferon-gamma (IFN-gamma) was compared to binding to untreated (resident) cells. IFN-gamma-treated macrophages bound fewer leishmania promastigotes than did untreated cells. The decreased binding was apparent over a wide dose range of parasite inocula when the assays were performed in the absence of exogenous complement. This decrease was specific to leishmania, since treated and untreated macrophages bound comparable amounts of immunoglobulin G- and complement-coated sheep red blood cells. Decreased parasite binding occurred early in the macrophage activation pathway. Pretreatment of macrophages with IFN-gamma for as little as 6 h, a time insufficient to induce other macrophage activation parameters, significantly reduced their ability to bind leishmania promastigotes. To determine the mechanism of this decreased phagocytosis by activated cells, macrophages were pretreated with specific inhibitors before the addition of leishmania. The binding of promastigotes to untreated (resident) macrophages was inhibited by approximately 50% by reagents that blocked either of two macrophage receptors, complement receptor type 3 (Mac-1) or a leishmania species-specific lectin-like receptor. Binding to IFN-gamma-treated macrophage populations, in contrast, was substantially inhibited only by antibody to Mac-1. Saccharides that were 50% inhibitory in the resident cell population, decreased binding by less than 10% in activated cells. The lack of saccharide inhibition by IFN-gamma-treated cells was also reflected in an inability of activated macrophages to bind to beads coated with purified leishmania lipophosphoglycan (LPG). These LPG-coated beads bound well to resident macrophages but poorly to activated cells. Thus, leishmania bind to macrophages by two distinct mechanisms, one that utilizes Mac-1 and a second mechanism that does not depend on complement and is saccharide inhibitable. These two binding mechanisms are distinct and differentially regulated in resident and activated cells.


Production of macrophage colony-stimulating factor by adult murine parenchymal liver cells (hepatocytes).

The activity of macrophage colony-stimulating factor (M-CSF) was found in the culture supernatant of mouse parenchymal liver cell fractions in a bone marrow colony-forming assay. The activity of an M-CSF-like substance purified by a four-step procedure was neutralized by goat anti-mouse M-CSF antiserum. M-CSF mRNA was detected in cellular RNA prepared from cultured parenchymal liver cell fractions by Northern blot analysis and also in cultured parenchymal liver cells by in situ hybridization. These results indicate that parenchymal liver cells have the capacity to produce M-CSF. We discuss the role of M-CSF in hematopoiesis, the immune response, and other biological phenomena.


Lipopolysaccharide impairs macrophage cytoplasmic pH regulation under conditions simulating the inflammatory microenvironment.

Within the acidic inflammatory milieu, macrophages (m phi s) must maintain their cytoplasmic pH (pHi) within a range conducive to optimal function. It was previously shown that metabolism of L-arginine at concentrations present in vitro in RPMI medium (1.14 mM) impairs the ability of m phi s to regulate pHi. However, concentrations of L-arginine in vivo reportedly range from approximately 100 microM in serum to less than or equal to 50 microM in wounds. To investigate the potential in vivo relevance of this inhibition, m phi pHi regulation was examined following incubation with low concentrations of L-arginine that mimic the inflammatory microenvironment, in the presence or absence of lipopolysaccharide (LPS). pHi regulation was evaluated as the ability of thioglycolate-elicited murine peritoneal m phi s to recover from an imposed cytoplasmic acid load. The m phi pHi was measured using a pH-sensitive fluorescent probe. Following incubation for 2 h in the absence of LPS, the pHi recovery rate was equivalent in cells incubated with and without L-arginine. Coincubation with LPS, however, resulted in marked inhibition of pHi recovery at L-arginine concentrations as low as 12.5 microM. The inhibition was not due to LPS alone, since LPS without L-arginine was not inhibitory. Inhibition of pHi recovery was observed at LPS concentrations ranging from 10 ng/ml to 10 micrograms/ml. The L-arginine-dependent inhibition was apparent within 60 min of exposure to LPS, in both freshly harvested cells and cells preincubated for 2 h in the absence of L-arginine and then exposed to both L-arginine and LPS. Under conditions mimicking the in vivo setting, LPS-stimulated L-arginine metabolism impairs m phi pHi regulation. Modulation of pHi by this mechanism may compromise m phi function within the acidic microenvironment of inflammation.


Exudation of proliferative macrophages in local inflammation in the peritoneum.

Thioglycollate (TG)-elicited peritoneal macrophages (m phi s) were highly proliferative and formed m phi colonies in vitro in the presence of m phi colony-stimulating factor (M-CSF), while resident peritoneal m phi s did not. To determine whether such proliferative m phi s are immigrant or locally activated resident m phi s, mice depleted of bone marrow cells and circulating monocytes by bone-seeking radiostrontium (89Sr) were injected intraperitoneally with TG. For control (88Sr) and splenectomized (Spx) mice, more than 4 x 10(4) m phi colony-forming cells (M-CFCs) per mouse were recovered in the peritoneal lavage fluid 5 days after TG injection. 89Sr-treated mice, on the other hand, had only 20% of those in the control mice. Splenectomized and 89Sr-treated (Spx/89Sr) mice showed further depletion of bone marrow cells and monocytes and, as expected, total numbers of peritoneal M-CFCs were severely depressed to less than 1% of those in the control mice. The results suggest that levels of peritoneal M-CFCs are strongly dependent on the presence of radiosensitive bone marrow cells and circulating monocytes, and resident peritoneal m phi s activated locally by inflammatory stimuli do not form m phi colonies under the defined conditions.


Change in the frequency of apoptosis after low- and high-dose X-irradiation of human lymphocytes.

The purpose of the present study was to correlate the type and frequency of cell death in human lymphocytes receiving variable doses of X-irradiation. Monocyte-depleted lymphocyte fractions were exposed in vitro to variable doses of X-rays of 0-20 Gy (0-2000 rads) and incubated for 4 and 16 h. An assessment of the mode of cell death (apoptosis vs. classical necrosis) was carefully evaluated using a multidisciplinary approach using light, fluorescence and electron microscopy (EM), and dye exclusion assays. Eosin Y exclusion assays indicated the absence of classical necrosis occurring in short-term cultures (4 h postirradiation). An assessment of cell counts, however, revealed a mean decrease of 4% at 0 Gy and 13% at 10-20 Gy (1000-2000 rads). The predominant mode of cell death was apoptosis, but the percent apoptotic cells (determined by EM) did not parallel this increase in cell loss with increasing radiation and actually decreased at doses above 5 Gy (500 rads). The discrepancy between percent cell loss and percent apoptosis was explained by a proposed change in overall duration of the apoptotic process. In long-term cultures (16 h postirradiation), a combination of classical necrosis, classical apoptosis, and combined apoptosis and necrosis (secondary necrosis of apoptotic cells) was apparent and was associated with a marked decrease in viability. Irradiation effects on lymphocytes showing none of the morphologic features of apoptosis or classical necrosis in short-term culture were evidenced by an increase in nuclear lobation. The results of this study indicate that the vast majority of peripheral blood lymphocytes are radioresistant. The use of irradiation in an in vitro model to study the biochemical events of the apoptotic process is also evaluated.


Tumor cell IL-6 gene expression is regulated by IL-1 alpha/beta and TNF alpha: proposed feedback mechanisms induced by the interaction of tumor cells and macrophages.

In the present report, we show that progressive growth of the immunogenic C57BL/6J sarcoma, MCA/76-9, was accompanied by an increase in serum interleukin-6 (IL-6) activity. The possible pathways leading to the induction of IL-6 release by the tumor cells are described. It was shown that macrophage products IL-1 alpha, IL-1 beta, and to a lesser extent, TNF alpha, induced the tumor cells in vitro to transcribe the IL-6 gene and release the gene product. IL-1 induced significantly more IL-6 mRNA and bioactivity than TNF alpha, although both cytokines induced a cumulative increase of bioactivity in the supernates over a period of 24 h. The tumor cells were shown to express receptors for IL-1 alpha, which could be blocked with anti-IL-1 receptor antibody. Given the previous reports that tumor-associated macrophages expressed both IL-1 alpha/beta and TNF alpha, the data suggest, first, that the mutual interaction of tumor cells and macrophages in situ may contribute to the observed increase in circulating IL-6 activity, and second, that the release of IL-6 in vivo may serve to regulate both anti-tumor immune responses and suppressor mechanisms.


A synthetic peptide homologous to retroviral envelope protein down-regulates TNF-alpha and IFN-gamma mRNA expression.

We investigated the influence of CKS-17, a synthetic heptadecapeptide that corresponds to a highly conserved domain of the immunosuppressive retroviral envelope protein p15E, on staphylococcal enterotoxin B (SEB)-induced TNF-alpha gene expression in human peripheral blood mononuclear cells and highly purified human monocyte preparations, as well as the production of TNF-alpha protein, using human peripheral blood mononuclear cells. RNA hybridization studies show that CKS-17 inhibits SEB-induced TNF-alpha mRNA accumulation in human peripheral blood mononuclear cells and human monocytes. CKS-17 is also shown to be highly suppressive for SEB-induced production of TNF-alpha proteins. Similarly, CKS-17 inhibits expression of SEB-induced IFN-gamma mRNA in human peripheral blood mononuclear cells. These results suggest that CKS-17 down-regulates both TNF-alpha and IFN-gamma production at mRNA level.


Intracellular cholesterol transport.

The intracellular movement of cholesterol in mammalian cells may involve complex pathways by which the sterol moves to various cellular sites and mediates transcriptional regulation, enzyme activation, and protein degradation. Current evidence indicates that there are three distinct pathways modulating intracellular cholesterol trafficking. The movement of endogenously synthesized cholesterol from the endoplasmic reticulum appears to be distinct from movement of exogenous, low density lipoprotein (LDL)-derived cholesterol to the plasma membrane. In addition, steroidogenic cells possess a third mechanism by which cholesterol is transported to the mitochondria to initiate steroid hormone synthesis. In this review, we have outlined the current knowledge of cholesterol transport mechanisms and pathways and have described approaches that may help define cholesterol trafficking mechanisms in molecular detail. The use of genetic and molecular biologic techniques can potentially reveal gene products that are involved in intracellular cholesterol transport and regulation as well as those that may secondarily affect this process.


Saposins: structure, function, distribution, and molecular genetics.

Saposins A, B, C, and D are small heat-stable glycoproteins derived from a common precursor protein, prosaposin. These mature saposins, as well as prosaposin, activate several lysosomal hydrolases involved in the metabolism of various sphingolipids. All four saposins are structurally similar to one another including placement of six cysteines, a glycosylation site, and conserved prolines in identical positions. In spite of the structural similarities, the specificity and mode of activation of sphingolipid hydrolases differs among individual saposins. Saposins appear to be lysosomal proteins, exerting their action upon lysosomal hydrolases. Prosaposin is a 70 kDa glycoprotein containing four domains, one for each saposin, placed in tandem. Prosaposin is proteolytically processed to saposins A, B, C and D, apparently within lysosomes. However, prosaposin also exists as an integral membrane protein not destined for lysosomal entry and exists uncleaved in many biological fluids such as seminal plasma, human milk, and cerebrospinal fluid, where it appears to have a different function. The physiological significance of saposins is underlined by their accumulation in tissues of lysosomal storage disease patients and the occurrence of sphingolipidosis due to mutations in the prosaposin gene. This review presents an overview of the occurrence, structure and function of these saposin proteins.


Different reactivities of high density lipoprotein2 subfractions with hepatic lipase.

Human high density lipoproteins2 (HDL2) consist of particles that contain both apolipoprotein (apo) A-I and apoA-II (A-I/A-II-HDL2) and others that contain apoA-I but are devoid of apoA-II (A-I-HDL2). When postprandial lipemia is pronounced, a fraction of HDL2 is converted into HDL2-like particles. These HDL3 exhibit lower apoA-I/apoA-II ratios than the parent HDL2, suggesting preferential conversion of A-I/A-II-HDL2 into HDL3 (J. Clin. Invest. 1984. 74: 2017-2023). Triglyceride transfer from triglyceride-rich lipoproteins to HDL2 and subsequent lipolysis by hepatic lipase are thought to mediate the conversion of HDL2 into HDL3. To understand why A-I/A-II-HDL2 are preferentially converted into HDL3, we separated postprandial HDL2 into A-I-HDL2 and A-I/A-II-HDL2 species by immunoaffinity chromatography using a monoclonal antibody for apoA-II, and determined the ability of HDL2 species i) to participate in protein-mediated lipid transfer; and ii) to interact with hepatic lipase in vitro. Triglyceride transfer from/to triglyceride-rich lipoproteins was similar for the two HDL2 species. In contrast, A-I/A-II-HDL2 were twice as effective as A-I-HDL2 in liberating hepatic lipase immobilized on HDL3-Sepharose. Lipolysis of triglycerides by hepatic lipase was 60% higher in postprandial A-I/A-II-HDL2 than in postprandial A-I-HDL2. Hydrolysis of phosphatidylcholine by hepatic lipase was threefold higher in A-II-containing HDL2 when compared with HDL2 devoid of apoA-II. The different lipolytic rates in HDL2 subspecies correlated with the size reduction of substrate lipoproteins. Reconstitution of postprandial A-I-HDL2 with apoA-II enhanced the rate of lipolysis by hepatic lipase to that observed in A-I/A-II-HDL2. We conclude that it is the interaction with hepatic lipase rather than the rate of triglyceride transfer that results in the preferred conversion of postprandial A-II-containing HDL2 into HDL3, and that apoA-II exerts a crucial role in this process.


Influence of eicosapentaenoic acid (20:5, n-3) on secretion of lipoproteins in CaCo-2 cells.

CaCo-2 cells, grown on filter membranes, were used to study the effects of fatty acids on cellular metabolism of triacylglycerol and phospholipids. The rate of triacylglycerol secretion was enhanced more than 2-fold, from 1 to 2 weeks after reaching confluency, in the presence of 0.6 mM fatty acids. Triacylglycerol secretion and oxidation of oleic acid increased 2- and 9-fold, respectively, with this culture system, as compared to cells grown on conventional plastic dishes. Eicosapentaenoic acid (20:5 n-3), when compared to oleic acid, did not reduce formation of triacylglycerol or enhance phospholipid synthesis in CaCo-2 cells during short term (less than 24 h) experiments, when the cells resided on membranes, regardless of what type of radioisotopes were used as precursors in the incubation media. However, the n-3 fatty acid was preferentially incorporated into phosphatidylinositol, lysophosphatidylcholine, and sphingomyelin, as compared to oleic acid. The disappearance from the apical medium and cellular uptake of labeled eicosapentaenoic and oleic acid were similar during incubations up to 24 h, and the metabolism of these fatty acids to acid-soluble materials and CO2 was equal. Light scattering analysis indicated that secreted lipoproteins of density less than 1.006 g/ml were in the same size-range as chylomicrons derived from human plasma. Assessment of secreted apolipoprotein B showed that by incubating CaCo-2 cells with oleic acid, apolipoprotein B levels increased approximately 1.4-fold when compared to cells incubated with eicosapentaenoic acid, whereas the amount of triacylglycerol and size-range of particles were similar for the two fatty acids. Our data indicate that CaCo-2 cells grown on filter membranes exhibit enterocyte-like characteristics with the ability to synthesize and secrete chylomicrons. Eicosapentaenoic acid and oleic acid are absorbed, metabolized, and influence secretion of lipoprotein particles in a similar way, except for some differences in incorporation of the fatty acids into certain phospholipid classes and a reduced secretion of apolipoprotein B. The culture conditions, including time after confluency and cellular support, are critical for the rate of secretion in the presence of eicosapentaenoic acid and oleic acid.


Incorporation of dietary [14C]arachidonic acid and [3H]eicosapentaenoic acid into tissue lipids during absorption of a fish oil emulsion.

A preferential incorporation of dietary arachidonic acid (20:4, n-6) into chyle lipoprotein phospholipids, a relative resistance of 20:4 esters of chyle triacylglycerol (TG) to hydrolysis by lipoprotein lipase, a preferential utilization of 20:4 for phospholipid acylation, and a low rate of oxidation of 20:4 are factors that may contribute to the differences seen in the incorporation into tissue lipids between absorbed 20:4 and the predominant dietary 16-18 carbon fatty acids. In this study we fed [14C]20:4 and [3H]eicosapentaenoic acid (20:5, n-3) as free fatty acids in a fish oil emulsion to rats and analyzed the radioactivity in different tissue lipids after 1, 2, and 4 h. The purpose was to examine the degree of similarity in the fate of the two major eicosanoid precursors during the absorption of a fish oil meal. The recovery after 2 and 4 h of 14C exceeded that of 3H in lipids of small intestine, serum, liver, heart, kidneys, and spleen. The differences increased with time, e.g., the liver contained 9.7 (+/- 0.7)% 3H and 17.9 (+/- 1.4)% of the 14C (P less than 0.001), and the upper half of the small intestine 10.0 (+/- 0.8)% of the 3H and 22.8 (+/- 1.1)% of the 14C (P less than 0.001) after 4 h. The 14C and 3H radioactivity per g tissue after 4 h ranked as follows: liver and brown adipose tissue greater than kidneys greater than heart, lungs, spleen, and serum greater than colon greater than white adipose tissue and testes, the differences between tissues being up to 50-fold. There were up to fourfold variations in the 14C/3H ratios between tissues after 4 h, the highest value being observed in the heart and the lowest in white adipose tissue. Of the radioactivity retained in liver and intestine, more 14C and 3H was in phospholipids and less in triacylglycerol (TG), the differences being largest in the liver, e.g., after 4 h 57.6 (+/- 0.8)% of the 14C and 29.9 (+/- 0.9)% of the 3H (P less than 0.001) in the liver was in phosphatidylcholine (PC). In both intestine and liver the highest 14C/3H ratios were found in phosphatidylinositiol (PI). Also phosphatidylethanolamine (PE) contained more 14C than 3H but the quantitative differences were relatively small after 4 h. In heart the proportions of 3H and 14C found in PE and PI did not differ, whereas more of the 14C was in PC and more of the 3H was in cardiolipin and phosphatidylserine.(ABSTRACT TRUNCATED AT 400 WORDS)


Effect of cutaneous permeability barrier disruption on HMG-CoA reductase, LDL receptor, and apolipoprotein E mRNA levels in the epidermis of hairless mice.

Disruption of the permeability barrier results in an increase in cholesterol synthesis in the epidermis. Inhibition of cholesterol synthesis impairs the repair and maintenance of barrier function. The increase in epidermal cholesterol synthesis after barrier disruption is due to an increase in the activity of epidermal HMG-CoA (3-hydroxy-3-methylglutaryl CoA) reductase. To determine the mechanism for this increase in enzyme activity, in the present study we have shown by Western blot analysis that there is a 1.5-fold increase in the mass of HMG-CoA reductase after acute disruption of the barrier with acetone. In a chronic model of barrier disruption, essential fatty acid deficiency, there is a 3-fold increase in the mass of HMG-CoA reductase. Northern blot analysis demonstrated that after acute barrier disruption with acetone or tape-stripping, epidermal HMG-CoA reductase mRNA levels are increased. In essential fatty acid deficiency, epidermal HMG-CoA reductase mRNA levels are increased 3-fold. Thus, both acute and chronic barrier disruption result in increases in epidermal HMG-CoA reductase mRNA levels which could account for the increase in HMG-CoA reductase mass and activity. Additionally, both acute and chronic barrier disruption increase the number of low density lipoprotein (LDL) receptors and LDL receptor mRNA levels in the epidermis. Moreover, epidermal apolipoprotein E mRNA levels are increased by both acute and chronic perturbations in the barrier. Increases in these proteins in response to barrier disruption may allow for increased lipid synthesis and transport between cells and facilitate barrier repair.


Water-phase palmitate concentrations in equilibrium with albumin-bound palmitate in a biological system.

The palmitate (PA) binding and transport capacity of human and bovine red cell membranes enables us to establish, in a biological system, the existence of a well-defined monomer concentration in equilibrium with PA bound to bovine serum albumin (BSA, 30 microM) inside the resealed red cell ghosts. Supernatants of suspensions of the [3H]PA-labeled ghosts contain a tiny quantity of dissolved binding capacities besides the monomer PA. This is demonstrated by linear regression of supernatant tracer concentrations versus ghost concentrations in a dilution series. The extrapolated value, corresponding to zero ghost concentration, is the monomer PA concentration in equilibrium with PA bound to BSA within the ghosts in molar ratio (nu). Measurements have been carried out for nu between 0.1 and 1.5 and at 0 degrees C, 10 degrees C, 23 degrees C and 38 degrees C. The important nu-dependent binding of PA to the ghost membrane itself enables us to use preparations of BSA-free ghosts in the same way, whereas this is impossible in the case of arachidonic acid. Within the physiological range of nu the PA monomer concentrations are accounted for by an apparent dissociation equilibrium constant (Kd) 3.4 10(-8) M at 38 degrees C calculated on basis of three equivalent binding sites per mol BSA. Kd depends on temperature with a well-defined enthalpy of 38.4 kJ/mol.