Maximum accuracy evaluation scheme for wireless saw delay-line sensors.

This paper describes an evaluation scheme that prevents phase ambiguity of surface acoustic wave (SAW) delay-line sensors. Although it is well-known that phase evaluation yields accuracies of 150~1500 times higher than time-delay evaluation, the problem of phase ambiguity has prevented phase evaluation of sensors operating over a range larger than 2 pi. This paper addresses this unsolved problem with a complete strategy. Furthermore, the existence of an optimum choice of the relative reflector positions on the sensor is shown. The presented relations enable the design of maximum accuracy SAW delay-line sensors.

Autoantibodies against malondialdehyde-modified LDL are elevated in subjects with an LDL subclass pattern B.

Small low density lipoproteins (LDL) are more susceptible to in vitro oxidation than larger LDL. To study whether this leads to more oxidation of small LDL in vivo, we determined the level of autoantibodies against malondialdehyde-modified LDL (MDA-LDL) in subjects with small or large LDL (LDL subclass pattern B or A) by ELISA. The study group consisted of 92 subjects with coronary heart disease without severe hypercholesterolemia (mean total plasma cholesterol 5.9 +/- 0.8 mM), 46 with an LDL subclass pattern A and 46 with an LDL subclass pattern B. In the subjects with LDL subclass pattern B the titre of autoantibodies of the IgM class against MDA-LDL was 29% higher than in the subjects with LDL subclass pattern A (P < 0.0001). The concentration of the anti-MDA-LDL autoantibodies of the IgM class was 58% higher in the patients with the pattern B than in the patients with the pattern A (P < 0.0001). There was no statistically significant difference in the titre or concentration of autoantibodies of the IgG class between subjects with LDL subclass patterns A and B. Besides plasma triglyceride and HDL cholesterol, the titre and concentration of the IgM autoantibodies were found to be independent predictors of the LDL subclass pattern. These results show that small LDL are associated with higher autoantibody levels than large LDL. Based on the assumption that the level of autoantibodies against MDA-LDL represents the rate of LDL oxidation in vivo, we conclude that in vivo small LDL is more readily oxidised than larger LDL.(ABSTRACT TRUNCATED AT 250 WORDS)

Risk of postoperative septic complications after abdominal surgical treatment in relation to perioperative blood transfusion.

A group of 548 patients was analyzed retrospectively to determine risk factors, particularly the perioperative administration of blood, for postoperative septic complications after intra-abdominal operations. Of the entire group, 198 (36.1 per cent) had at least one complication. The postoperative mortality rate was 0.9 per cent. Using univariate analysis, blood transfusion, serum protein concentration, gastric malignant disease, total gastrectomy, anastomotic dehiscence, diabetes mellitus, the surgeon and perioperative antibiotics were significant factors influencing the rate of postoperative septic complications. After adjustment for all these factors, logistic regression analysis was used to study the effect of perioperative blood transfusion. Age, serum protein concentration, antibiotics, extended malignant disease of the colon, gastric operation, total colectomy, operation performed by staff members and anastomotic dehiscence were significant independent factors. Blood transfusion per se was not significant (p = 0.07). In patients who received more than 3 units of blood, the postoperative septic complication rate was significantly elevated (p = 0.003). We conclude that the perioperative administration of blood may negatively influence the risk of developing postoperative septic complications after intra-abdominal operations.

[Fecal incontinence following obstetrical injury; significance of damaged pelvic floor innervation and results of surgical treatment]. / Incontinentie voor faeces na obstetrisch letsel; betekenis van beschadigde bekkenbodeminnervatie en resultaten van chirurgische behandeling.

During the last 5 years 33 patients with faecal incontinence due to childbirth were investigated. Ages varied from 23 to 61 and duration of symptoms from 0.3 to 25 years. Anal manometry was performed in all patients and electromyography was performed in 21 cases. Twenty-seven patients underwent delayed sphincter repair. Continence was restored in 21 (81%). Post-operatively performed EMG in the patients who remained incontinent demonstrated severe denervation but sphincter mapping did not demonstrate muscle discontinuity. Continence improved in three patients within one year as results of reinnervation. Faecal incontinence after childbirth may be due to either obstetric rupture or denervation. Both disorders may coexist. Sphincter repair gives excellent results provided denervation is not present. Preoperative assessment by EMG is mandatory.

Some factors influencing the outcome of stoma surgery.

In a retrospective study, the procedure and follow-up of 266 patients with 345 stomas on the small and large bowel were reviewed to reveal possible etiologic factors for stomal complications. The overall complication rate for creating a stoma was 36 percent. No differences in overall complication rate were encountered when comparing acute and elective management; however, high output stomas and necrosis were encountered more often in the acutely managed group. Preoperative contamination was followed more often by stomal retraction. Septic events, however, occurred less frequently than in the noncontaminated procedures. Adequate supply with antibiotics might account for the lack of difference in these complications between the two groups. Antibiotics might not have prevented low-grade infections giving rise to retractive reaction. The influence of body weight was evaluated by the Quetelait index. It was demonstrated that moderate obesity had no significant influence on the outcome of the procedure. Adipose patients had a statistically significant larger number of necroses. This may be due to the relatively short and fatty mesenterium causing a compromised circulation. The outcome of stoma surgery was greatly influenced by bowel quality. Crohn's disease and bowel ischemia were encountered in 50 percent of stoma complications. In ischemic disease, significantly more necrosis was found. Retraction of the stoma occurred more often in Crohn's disease. Chronic ulcerative colitis did not have a higher complication rate.

Rectal prolapse; a review of Dutch surgical practice.

Many different technics have been described for the treatment of rectal prolapse. Transabdominal fixation of the rectum is the procedure currently most favoured, as in The Netherlands, where the majority of patients with rectal prolapse are treated in this way. A questionaire sent to all teaching hospitals showed that in only seven out of 27 hospitals postanal repair is carried out in cases of postoperative fecal incontinence.

Fecal incontinence and the anorectal angle.

The role of the pelvic floor musculature was assessed in fecal incontinence by comparing the anorectal angle with the anal resting pressure. Twenty five patients were investigated; nine patients were incontinent. It appeared that a decrease in anal resting pressure was associated with an increase of the anorectal angle. In other words, impairment of fecal control was associated with a diminished activity of the pelvic floor musculature. In view of the fact that diminished anal sensation and anal pressure at maximal squeeze are found in fecal incontinence, it is probable that fecal incontinence is caused by pudendal nerve injury.

Diagnosis and treatment of fistula-in-ano.

The operative treatment for anal fistula in 51 patients began with an intra-anal procedure to detect the internal opening. It was located in all cases by operative inspection and the use of a hooked probe. Pre-operatively, the internal opening was identified by digital examination in 98%. All internal openings were located at the dentate line; 68.9% were found in the posterior quadrant. In 14 cases a high extension was found; horseshoeing occurred in 9 cases. The recurrence rate was 4%: in two cases a high extension was missed, but both were cured by a second operation. Anal control was slightly impaired in 10%.

Anal manometry, its applications and indications.

A manometric system is described to record the anal high-pressure zone. Anal manometry was performed in 77 individuals. It appeared that amplitude at rest is the most suitable variable to assess sphincter strength. Anal manometry is indicated in patients with chronic constipation or faecal incontinence. It may also be applied to postoperative assessment of operative procedures involving sphincter control.