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Biomedical subjects

A Dolk

Publications and source records attributed to A Dolk.

At least 19 recordsLinked to original sources
PubMed2000

Somatic mutations of the APC, KRAS, and TP53 genes in nonpolypoid colorectal adenomas.

Colorectal adenomas are macroscopically visible morphological changes of the mucosa that can develop focal carcinoma in the absence of surgical intervention. The successive molecular changes proposed to occur at different stages in the adenoma-carcinoma sequence were primarily based on DNA studies of exophytic, polypoid-type adenomas. Not all colorectal lesions, however, display an exophytic phenotype and a presumed distinct colorectal neoplasm, the nonpolypoid adenoma, was subsequently described as a precursor of colorectal cancer. The low incidence of KRAS mutations in nonpolypoid colorectal adenomas reported previously suggested a different genetic basis for the transformation process in these lesions. We have pursued the identification of genetic changes in benign sporadic nonpolypoid colorectal adenomas in a selected Swedish patient group with no family history of colorectal cancer. Mutation screening of the adenomatous polyposis coli (APC), KRAS, and TP53 genes was conducted using the protein truncation test, heteroduplex-single-strand conformation polymorphism analysis, and denaturing gradient gel electrophoresis on PCR-amplified fragments. Fourteen mutations in the APC gene were characterized in 10/20 samples. Mutations in the KRAS and TP53 genes were identified in 3/57 and 4/51 adenomas, respectively. The mutation frequencies and distribution of mutations in APC correlate with published data on exophytic adenomas. The low mutation frequency of the TP53 gene is consistent with the benign nature of the research material. KRAS activation (an early event in polypoid colorectal adenomas) apparently does not play a significant role in nonpolypoid adenoma development but may result in the development of a polypoid configuration. Genes Chromosomes Cancer 27:202-208, 2000.

Adenoma↗
PubMed1999

Whole gut transit is prolonged after Ripstein rectopexy.

OBJECTIVE: To find out if there are changes in transit time after Ripstein rectopexy and whether measurement of whole gut transit time preoperatively can predict postoperative constipation. DESIGN: Prospective open study. SETTING: Teaching hospital, Sweden. SUBJECTS: 30 patients undergoing Ripstein rectopexy for rectal prolapse (n = 17) or internal rectal intussusception (n = 13). METHODS: Whole-gut transit studies and recording of symptoms of constipation preoperatively and postoperatively. MAIN OUTCOME MEASURES: Constipation and retention of markers. RESULTS: Significantly more markers were retained in postoperative compared with preoperative transit studies (p < 0.001). Constipation mainly presented as emptying difficulties and there was no increase in the total number of patients who reported emptying difficulties postoperatively. There was a weak but significant correlation between retention of markers preoperatively and postoperative emptying difficulties (p < 0.05). CONCLUSION: Whole gut transit was prolonged after Ripstein rectopexy. Preoperative retention of markers indicated an increased risk of postoperative constipation.

Adolescent↗
PubMed1999

Anal incontinence after vaginal delivery: a prospective study in primiparous women.

OBJECTIVE: To investigate the incidence and degree of anal incontinence after vaginal delivery among primiparous women and to define associated risk factors. DESIGN: Prospective observational study. SETTING: Karolinska Institutet, Danderyd Hospital, Sweden, a university hospital. PARTICIPANTS: Three hundred and forty-nine primiparous women. METHODS: Questionnaires distributed within the first days after delivery and re-distributed five and nine months postpartum. Analysis of delivery records. RESULTS: Eighty percent of the women answered all questionnaires. At five months postpartum, 2% of the women had symptoms of faecal incontinence and 25% had symptoms of involuntary flatus. At nine months postpartum, 1% of the women had symptoms of faecal incontinence and 26% had symptoms of involuntary flatus. The majority of the women had infrequent symptoms and a decrease in severity was noted at nine months. Symptoms of incontinence were more common in women who sustained a sphincter tear at delivery. Risk factors for incontinence at five months included maternal age, duration of the second stage of labour, instrumental vaginal delivery, and clinically diagnosed sphincter tear at delivery. Development of incontinence at nine months was associated with maternal age and clinically diagnosed sphincter tear at delivery. CONCLUSIONS: The present study demonstrates that infrequent involuntary flatus is a common symptom after vaginal delivery in primiparous women. These symptoms of involuntary flatus frequently improved and only a few women suffered from frank faecal incontinence. Factors associated with an increased risk of anal incontinence and sphincter tears should be considered during delivery.

Adult↗
PubMed1998

Preoperative electrophysiologic assessment cannot predict continence after rectopexy.

PURPOSE: The aim of this study was to evaluate preoperative electrophysiologic assessment for prediction of anal continence after rectopexy. METHODS: Forty-three patients with rectal prolapse (n = 26) or internal rectal intussusception (n = 17) underwent concentric-needle electromyography, fiber density determination by single-fiber electromyography of the external anal sphincter, and pudendal nerve terminal motor latency evaluation before Ripstein rectopexy. A detailed history was obtained from each patient preoperatively and postoperatively. RESULTS: Anal continence was improved after rectopexy, both in patients with rectal prolapse (P = 0.06) and in those with internal rectal intussusception (P = 0.003). Abnormal results were registered in one or several aspects of the electrophysiologic assessment in 31 (72 percent) of the patients. However, functional outcome with respect to continence was not predicted by preoperative electromyography or pudendal nerve terminal motor latency assessment results. CONCLUSION: Electrophysiologic examinations in the preoperative assessment of patients with rectal prolapse and internal rectal intussusception do not predict continence after the Ripstein rectopexy. The routine use of electrophysiologic assessment requires further definition.

Action Potentials↗
PubMed1998

Paradoxical sphincter reaction is influenced by rectal filling volume.

PURPOSE: Paradoxical sphincter reaction is frequently found in constipated patients but sometimes also in incontinent patients and in asymptomatic subjects. Its significance in defecation disorders has, therefore, been debated. The aim of the present study was to investigate whether paradoxical sphincter reaction is influenced by rectal filling volume. PATIENTS AND METHODS: Eighteen patients with defecation disorders and paradoxical sphincter reaction shown by electromyography were reinvestigated with an extended electromyographic investigation while in the lying position and while in the sitting position, with 50-ml, 100-ml, and 150-ml water-filled rectal balloons. RESULTS: All 18 patients showing paradoxical sphincter reaction in the first investigation also showed the reaction at the second investigation in the lying position with a 0-ml volume of rectal contents. In the sitting position, with a volume of 150 ml of rectal contents, the increase in electromyographic activity disappeared in seven patients (39 percent) and no longer showed paradoxical sphincter reaction. Electromyography showed decreased activity in one patient and unchanged activity in six patients during straining. A closing reflex was seen after completed straining in all of these seven patients. CONCLUSIONS: The present study demonstrates that paradoxical sphincter reaction diagnosed by electromyography is influenced by the rectal filling volume and might diminish when the rectum is filled with contents. The conventional electrophysiologic technique in the diagnosis of paradoxical sphincter reaction might, therefore, overdiagnose this condition.

Adult↗
PubMed1997

Internal rectal intussusception seldom develops into total rectal prolapse.

PURPOSE: This study was designed to analyze how often internal rectal intussusception develops into total rectal prolapse. METHODS: Repeated investigations with defecography were performed in 312 patients because of persisting symptoms. In 79 patients who had a rectal intussusception at the first defecography, results of the second defecography and the patients' records were studied. RESULTS: A total of 38 patients had not undergone any surgical treatment of rectal intussusception or rectal prolapse between the first and second defecographies. One of these patients had a rectal prolapse at the second defecography, and another developed a clinical prolapse after the second defecography. CONCLUSIONS: The present study demonstrates that the risk of developing a rectal prolapse in patients with rectal intussusception is small. This risk should, therefore, not be used as an indication for surgery.

Administration, Oral↗
PubMed1996

Continence is improved after the Ripstein rectopexy. Different mechanizms in rectal prolapse and rectal intussusception?

PURPOSE: This study was undertaken to evaluate anal manometric changes after Ripstein's operation for rectal prolapse and rectal intussusception and to study the clinical outcome following the operation, with special reference to anal incontinence. METHODS: Forty-two patients with rectal prolapse or rectal intussusception were subjected to anorectal manometry preoperatively and seven days and six months postoperatively. A detailed history was obtained from each patient preoperatively and six months postoperatively. RESULTS: Preoperatively, patients with rectal intussusception had higher maximum resting pressure (MRP) (52+/- 23 mmHg) than patients with rectal prolapse (34 +/- 20 mmHg; P < 0.01). In the group of patients with rectal prolapse, there was a postoperative increase in MRP after six months (P < 0.001) but not after seven days. Maximum squeeze pressure (MSP) did not increase. Neither MRP nor MSP increased postoperatively in patients with internal rectal procidentia. Continence was improved postoperatively both in patients with rectal prolapse (P < 0.01) and rectal intussusception (P < 0.01). There was no postoperative increase in rectal emptying difficulties. CONCLUSION: Ripstein's operation often improved anal continence in patients with rectal prolapse and rectal intussusception. This improvement was accompanied by increased MRP in patients with rectal prolapse, indicating recovery of internal anal sphincter function. No postoperative increase in MRP was found in patinets with rectal intussusception. This suggests an alternate mechanism of improvement in patients with rectal intussusception.

Adult↗
PubMed1996

Nitrous oxide: a valuable alternative for pain relief and sedation during routine colonoscopy.

BACKGROUND AND STUDY AIMS: Patient-administered nitrous oxide in 50% oxygen has lately come into use as an alternative to combined opioid and benzodiazepine medication for colonoscopic procedures. A randomized study was carried out comparing intramuscular pethidine hydrochloride 1 mg/kg with inhalation of Medimix (a mixture of nitrous oxide in oxygen 50%) for relief of pain and anxiety during colonoscopy. PATIENTS AND METHODS: Thirty-eight patients (19 in the pethidine group and 19 in the nitrous oxide group) were studied. The following parameters were measured: blood pressure, pulse rate, and arterial oxygen saturation. At the end of the colonoscopy and before the patients left the ward, pain, nausea, and general well-being were evaluated by the patients using a visual analogue scale. The colonoscopy time, investigation conditions and the total length of hospital stay were registered. RESULTS: Colonoscopy time and the colonoscopists' opinions concerning the investigation conditions did not differ between the groups. Pain relief and patient evaluation of the total procedure were also equal between the patient groups. However, there was less nausea among the Medimix patients. Three patients in the pethidine group had oxygen saturations below 92%. There was no desaturation during and five minutes after colonoscopy in the Medimix group. Patients in the Medimix group left the hospital on average 34 minutes earlier than patients in the pethidine group. CONCLUSIONS: We conclude that the use of nitrous oxide (Medimix) as an analgesic is as good as pethidine for colonoscopy. Medimix has clear advantages compared to pethidine in terms of reducing nausea and shortening the hospital stay.

Adult↗
PubMed1995

Results of rectocele repair. A prospective study.

PURPOSE: This study was designed to evaluate the results of rectocele repair and parameters that might be useful in selecting patients for this operation. METHODS: Twenty-five patients with symptom-giving rectoceles were prospectively evaluated with a standardized questionnaire, physical examination, defecography, colon transit studies, anorectal manometry, and electrophysiology. Patients underwent posterior colporrhaphy and perineorrhaphy. They were followed postoperatively (mean, 1.0 year) with the same questionnaire, physical examination, defecography, anorectal manometry, and electrophysiology. RESULTS: Constipation had improved postoperatively in 21 of 24 constipated patients (88 percent). At postoperative follow-up 13 patients (52 percent) had no constipation symptoms, 8 (32 percent) had occasional symptoms, and 4 (16 percent) had symptoms more than once per week. Four patients with rectocele at preoperative defecography, but not at physical examination, had favorable outcomes following surgery. The majority of patients not using vaginal digitalization preoperatively had improved with respect to constipation. All patients with pathologic transit studies had various degrees of constipation postoperatively. Constipation was not improved in two of five patients with preoperative paradoxic sphincter reaction. CONCLUSIONS: Rectocele is one cause of constipation that can be treated with good results. Preoperative use of vaginal digitalization is not mandatory for a good postoperative result. Defecography is an important complement to physical examination. Patients with pathologic transit study might have a less favorable outcome of rectocele repair with respect to constipation. More studies about the significance of paradoxic sphincter reaction in these patients are indicated.

Adult↗
PubMed1994

Enterocele demonstrated by defaecography is associated with other pelvic floor disorders.

Sixty-nine patients with enterocele on defaecography, and 128 patients without enterocele but with other abnormal findings were investigated to identify concomitant colorectal disorders and their relationship with enterocele. Of the 69 patients with enterocele, 38 (55%) had concomitant rectal intususception and 26 (38%) rectal prolapse. Abnormal physiological findings on anorectal manometry and electrophysiology were more common in patients with enterocele. Previous hysterectomy increased the risk of enterocele formation. The study has demonstrated that patients with enterocele should be investigated thoroughly for other lesions before treatment is planned. Further investigation of the role of enterocele in patients with defaecation disorders is required.

Adolescent↗
PubMed1994

Defecography. Results of investigations in 2,816 patients.

PURPOSE: This study was designed to analyze the frequency of different findings at defecography in patients with defecation disorders and see in what way the evaluation could be improved. METHODS: The reports of investigations in 2,816 patients were analyzed. RESULTS: Twenty-three percent of the investigations were considered normal. Thirty-one percent of the patients had rectal intussusception, 13 percent had rectal prolapse, 27 percent had rectocele, and 19 percent had enterocele. Twenty-one percent of the patients had a combination of two or three of these diagnoses. The combination of rectocele and enterocele was rare. The majority of patients with enterocele had other concomitant findings. Patients with or without abnormal perineal descent had similar frequencies of rectal prolapse, rectal intussusception, and enterocele. Rectocele was more common in patients with abnormal perineal descent. CONCLUSIONS: Defecography is valuable when investigating patients with defecation disorders. Pathologic findings were found in 77 percent of the patients. A standardized protocol should ensure a complete evaluation of defecography.

Adolescent↗
PubMed1994

Enterocele is correctable using the Ripstein rectopexy.

PURPOSE: About one-third of the patients with rectal prolapse or rectal intussusception have concurrent enterocele at defecography. The purpose of this study was to evaluate the effect of the Ripstein procedure on the concurrent enterocele and to study the outcome of the procedure with respect to the patients' symptoms. METHODS: Twenty-two patients with enterocele and either rectal prolapse or rectal intussusception at defecography were treated using the Ripstein procedure. Postoperatively, the patients were evaluated with clinical examination (22 patients) and defecography (16 patients). RESULTS: None of the patients had recurrence of enterocele, rectal prolapse, or intussusception at postoperative follow-up. Continence was improved in 15 of 16 incontinent patients. Emptying difficulties were unchanged in eight patients, improved in five patients, and had deteriorated in four patients. CONCLUSIONS: Enterocele is corrected by using the Ripstein rectopexy. Persisting defecation difficulties after the Ripstein procedure are unlikely to be secondary to enterocele. The Ripstein procedure can be an alternative in the treatment of enterocele, as a majority of these patients also have rectal prolapse or rectal intussusception.

Defecation↗
PubMed1992

Paradoxical sphincter reaction and associated colorectal disorders.

Of 71 patients with paradoxical sphincter reaction, 54 had symptoms of constipation or outlet obstruction and 17 were incontinent. The patients were investigated with defecography, colon transit time, anorectal manometry and electromyography. Ninety-six percent of the patients had additional changes in anorectal anatomy and physiology; 70% of the patients had abnormal defecography and 42% had delayed colon transit time. Decreased maximal anal pressure (MAP) and maximal squeeze pressure (MSP), indicating impaired function of the anal sphincters might be one reason for incontinence in patients with paradoxical sphincter reaction. The paradoxical reaction occurred in the puborectalis muscle and in three tested sites in the external sphincter. It is sufficient to record the EMG activity in one muscle and at one point to diagnose a paradoxical sphincter reaction. The absence of a normal closing reflex on electromyography is evidence for a paradoxical sphincter reaction. Denervation was more pronounced in the external sphincter than in the puborectalis muscle. The right pudendal nerve was subjected to damage more often than the left nerve.

Adolescent↗
PubMed1992

Association between rectocele and paradoxical sphincter response.

Rectocele as well as paradoxical sphincter reaction may lead to rectal emptying difficulties and outlet obstruction. Forty-one patients with emptying disturbances and rectocele were investigated with defecography, anorectal manometry, colon transit time, and electromyography. Twenty-nine patients (71 percent) had concomitant paradoxical sphincter reaction, and 13 of these also had increased colon transit time. The functional results after surgical treatment of rectocele are not always satisfactory, probably because patients often have several causes for their emptying disturbances. It is emphasized that careful preoperative investigations are important before surgical treatment of rectocele in patients with emptying difficulties.

Adult↗
PubMed1991

The effect of yoga on puborectalis paradox.

Nine patients with severe defaecation difficulties primarily considered to be due to puborectalis dysfunction (puborectalis paradox), verified by electromyography (EMG) of the striated anal sphincter muscles, were offered training in Yogic techniques of relaxation and muscle control in order to change the activity of the pelvic floor muscles during attempted defaecation. Five patients completed the training program of 20 2-hour sessions and were re-examined clinically and with EMG. One patient regained a normal EMG pattern but none of the patients improved clinically.

Adult↗
PubMed1991

Is paradoxical sphincter reaction provoked by needle electrode electromyography?

In 10 patients with emptying disturbances, the anal sphincter reaction was investigated clinically and by electromyography with needle and wire electrodes to elucidate whether pain during the investigation could provoke the paradoxical sphincter reaction. In eight of the patients, the paradoxical reaction was easily felt at digital examination. Two patients complained of pain during the needle electrode recording; none complained during the wire electrode investigation. Nevertheless, all 10 patients had paradoxical sphincter reaction independent of the electrode used at electromyography. With careful clinical investigation, most cases of paradoxical sphincter reaction can be diagnosed. When this is inconclusive, the diagnosis should be confirmed by electromyography, preferably by the wire technique.

Adult↗
PubMed1990

Slow transit chronic constipation (Arbuthnot Lane's disease). An immunohistochemical study of neuropeptide-containing nerves in resected specimens from the large bowel.

Seven patients (6 women, 1 man) with severe idiopathic chronic constipation, who underwent surgery with subtotal colectomy and ileorectal anastomosis, were investigated for the occurrence and density of nerve fibres, immunoreactive to different neuropeptides in the mucosa, submucosa, ganglia and smooth muscle in fresh specimens from the colon ascendens, the colon transversum and the colon descendens-sigmoideum. The following substances were studied: enkephalin, substance P, somatostatin, neuropeptide Y, vasoactive intestinal polypeptide, calcitonin gene-related peptide, bombesin, motilin, tyrosine hydroxylase, dynorphin and galanin. Nerve fibres immunoreactive to CGRP occurred in large numbers in the myenteric ganglia of the patients with severe idiopathic chronic constipation, whereas in the myenteric ganglia of the control cases they only occurred in low numbers. In two patients there was no detectable motilin immunoreactivity and in one patient only sparse in the mucosa and the smooth muscle. The other neuropeptides investigated occurred in the density and distribution previously reported in the normal gut. With the present technique there were indications that patients with severe idiopathic chronic constipation have a significant difference in the occurrence of immunoreactive nerve fibres to CGRP and motilin compared to control patients.

Adult↗