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Biomedical subjects

Michael A Kamm

Publications and source records attributed to Michael A Kamm.

12 recordsLinked to original sources

Assessment of the predictive value of a bowel symptom questionnaire in identifying perianal and anal sphincter trauma after vaginal delivery.

PURPOSE: The purpose of this study was to determine whether a postpartum bowel-habit questionnaire could reliably identify females who had sustained perineal and anal sphincter trauma after vaginal delivery. METHODS: A prospective cohort design was used to recruit 156 consecutive primigravid females, of whom 134 delivered vaginally without clinical evidence of a third-degree tear. These 134 females completed a specific anal continence questionnaire and underwent anal endosonography before and after delivery to identify those with postpartum deterioration in anal continence and to relate this to sonographic evidence of anoperineal trauma. RESULTS: Anal continence deteriorated in 37 females (27.6 percent) after delivery, 16 of whom (43.2 percent) had sonographic evidence of trauma. There was no postpartum deterioration of continence in the remaining 97 females, 17 (17.5 percent) of whom had sonographic evidence of trauma. Sensitivity, specificity, positive predictive value, and negative predictive value of the questionnaire for sonographic trauma were 48.5, 79.2, 43.2, and 82.5 percent, respectively, with corresponding values of 57.1, 75.8, 21.6, and 93.8 percent for external anal sphincter disruption. CONCLUSION: A bowel-habit questionnaire will detect approximately 60 percent of females who sustain external sphincter tears after vaginal delivery.

Adult↗

Use of probiotics in the treatment of inflammatory bowel disease.

The gut flora plays a fundamental role in maintaining normal intestinal function. A disturbance of this flora, or the host response to this flora, has been clearly demonstrated to play a role in the pathogenesis of inflammatory bowel disease (IBD). This has led to attempts to modify the bacterial flora with "live non-pathogenic organisms that confer health benefits by improving the microbial balance," otherwise known as probiotics. Recent attention has focused on this potential strategy to treat or prevent IBD. The potential therapeutic benefit is enhanced by the natural and apparently safe approach that probiotics offer. Animal models of colitis have provided the proof of principle that probiotics can prevent and treat established intestinal inflammation. Controlled clinical studies have demonstrated the efficacy of probiotics in the maintenance of remission of pouchitis, prophylaxis of pouchitis after the formation of an ileoanal reservoir, maintenance of remission of ulcerative colitis, and treatment of Crohn's disease. However, large controlled trials are needed to definitively establish the place for probiotics in the treatment of IBD and resolve issues such as the dose, duration, frequency of treatment, and use of single or multiple strains. Research is focusing on establishing the mechanism of action, so that treatments with individually tailored properties are developed and innovative approaches are explored.

Animals↗

Intestinal dendritic cells increase T cell expression of alpha4beta7 integrin.

The integrin alpha4beta7 binds to MAdCAM-1 and contributes to homing of lymphocytes to gut and other mucosal tissues. In humans, the alpha4beta7(hi) subset of circulating memory cells appears to have been primed in mucosal tissues. The factors that determine whether alpha4beta7(lo) naive cells become alpha4beta(hi) or alpha4beta7(-) cells upon differentiation are poorly understood but could include an influence of the activating antigen-presenting cell. To address this point, the induction of alpha4beta7 following activation of mouse cells with the APC-dependent stimulus soluble anti-CD3 has been examined. Almost all mouse T cells freshly isolated from mesenteric lymph nodes (MLN) and peripheral (PLN; axillary, brachial and inguinal) lymph nodes stained only weakly for alpha4beta7 but a subpopulation became alpha4beta7(hi) upon activation with anti-CD3 in a cell cycle- and accessory cell-dependent manner. A small proportion (approximately 1.5 %) of the starting cells gave rise to alpha4beta7(hi) cells after culture. A higher proportion of alpha4beta7(hi) cells were generated in MLN than PLN cultures. Peyer's patch cultures gave intermediate values. In crossover experiments, MLN dendritic cells (DC) induced higher proportions and numbers of alpha4beta7(hi) cells than PLN DC irrespective of the source of T cells. Therefore, in addition to their other immunoregulatory roles, DC have the potential to shape immune responses by influencing the homing of the lymphocytes they activate.

Animals↗

Dynamic magnetic resonance imaging evaluation of the structural and functional results of postanal repair for neuropathic fecal incontinence.

PURPOSE: The aim of this study was to determine whether dynamic magnetic resonance imaging of the pelvic floor can discriminate between patients who improve after postanal repair for neurogenic fecal incontinence and those who remain symptomatic. METHODS: Pelvic floor measurements obtained during dynamic magnetic resonance imaging in eight females whose anal incontinence had improved after postanal repair were compared with those from nine females who remained symptomatic. All subjects also underwent standard anorectal physiology testing. RESULTS: There was no significant difference between groups with respect to any measurement of anterior or middle pelvic floor compartments. Additionally, there was no difference in posterior pelvic floor configuration when symptomatic patients were compared with those who had improved. However, dynamic magnetic resonance measurements revealed patients who remained symptomatic had significantly greater posterior pelvic floor weakness. Anorectal physiology was unable to differentiate between groups. CONCLUSIONS: There is no difference in static pelvic floor measurements when subjects remaining symptomatic after postanal repair are compared with those who have improved. In contrast, dynamic measurements may be able to predict failure in those who demonstrate excessive posterior pelvic floor mobility.

Adult↗

Influence of the subpubic arch angle on anal sphincter trauma and anal incontinence following childbirth.

OBJECTIVE: To assess the relationship between the subpubic arch angle, anal sphincter and perineal trauma, and anal incontinence after childbirth in nulliparous women. DESIGN: Prospective cohort study. SETTING: University teaching hospital. SAMPLE: One hundred thirty-four low risk nulliparous women. METHODS: Measurements of the bony pelvic outlet were made to calculate the subpubic arch angle. Endosonographic assessment of the perineum and anal sphincter was made before and after delivery. A specific bowel function questionnaire was completed before and after delivery. MAIN OUTCOME MEASURES: Perineal and anal sphincter trauma, and deteriorating anal continence after delivery. RESULTS: Thirty-two women with a subpubic arch angle of less than 90 degrees had significantly prolonged first and second stages of labour when compared with 102 women whose subpubic arch was wider. Following delivery, anal continence deteriorated in more women with a narrow subpubic angle (69% vs 21%, P < 0.001) but this was unrelated to the incidence of anal sphincter and perineal trauma. CONCLUSIONS: A narrow subpubic arch is strongly associated with prolonged labour and postpartum anal incontinence in nulliparous women. However, perineal and anal sphincter trauma, assessed by ultrasound, does not account for the higher rate of postpartum analincontinence in women with a narrow subpubic arch angle.

Adult↗

Pathophysiology of diverticular disease.

There is substantial evidence that colonic diverticulosis is related to civilization, industrialization and a "Western" lifestyle and diet, being described as "a disease of Western civilization". Its increased incidence during the 20th century and the morbidity and mortality associated with complications, demand that this condition should receive greater attention in terms of aetiology, prevention and management. It is generally believed that low dietary fibre and ageing are the two main pathogenic factors involved in this disease. Physiological studies have also demonstrated that there is a higher intraluminal pressure in the large bowel with diverticula. This chapter provides the evidence currently available for the pathophysiology of colonic diverticulosis and discusses its aetiological factors, including low dietary fibre, ageing and intraluminal pressure as well as extracelluar matrix such as collagen and elastin. The difference between the left-sided diverticulosis commonly seen in Caucasians and the right-sided predominantly observed in Asians is also presented.

Aging↗

Psychological state and quality of life in patients having behavioral treatment (biofeedback) for intractable constipation.

OBJECTIVE: Behavioral techniques, including biofeedback, improve symptoms in a majority of patients with intractable idiopathic constipation. However, it is unknown whether there is also improvement in patients' psychological well-being and quality of life (QOL). It is also unknown whether psychological or QOL factors can be used to predict the response to treatment. We aimed to assess these factors prospectively. METHODS: Thirty-one consecutive patients (median age 36 yr) receiving biofeedback retraining for idiopathic constipation were studied. A bowel symptom record, the General Health Questionnaire-28 (GHQ-28) (n = 31) and Hospital Anxiety and Depression Scale (n = 20), both psychological measures, and the Short Form-36 (SF-36) (n = 22), a generic QOL measure, were recorded before and after treatment. RESULTS: Twenty-two of the patients felt subjectively symptomatically improved. When considering all patients, treatment resulted in decreased depression (p < 0.05), anxiety (p < 0.05), and somatic symptoms (p < 0.01) (psychological measures: GHQ-28), and improved general health (p < 0.05) and vitality (p < 0.05) (QOL measures: SF-36). Patients who improved symptomatically showed significantly higher scores on the GHQ-28 and SF-36, in contrast to the unchanged scores in patients who did not symptomatically improve. Pretreatment GHQ-28 did not predict who would benefit from treatment, but patients in whom pain, emotional problems, or low vitality interfered with daily living (SF-36 pain subscales) were significantly (p < 0.05) less likely to respond to treatment. CONCLUSIONS: The symptomatic improvement produced by biofeedback in constipated patients is associated with improved psychological state and QOL. Some of the psychological morbidity in these patients is reversible. QOL parameters may be useful for predicting a likely response to treatment.

Adult↗

Female anal sphincter: age-related differences in asymptomatic volunteers with high-frequency endoanal US.

PURPOSE: To evaluate endoanal ultrasonographic (US) anatomy in a large group of nulliparous women by using a high-frequency 10-MHz transducer to define normal age-related differences in sphincter morphology. MATERIALS AND METHODS: One hundred fifty asymptomatic nulliparous women (mean age, 31 years; range, 19-80 years) underwent endoanal US with a high-frequency 10-MHz transducer. Anal canal structures were measured at high, middle, and low levels and were correlated with age by using the Pearson simple linear correlation coefficient. RESULTS: Internal sphincter thickness showed a highly significant positive correlation with age at both sites at which it was measured (high anal canal, r = 0.34, P <.001; middle anal canal, r = 0.33, P <.001). External sphincter thickness showed a highly significant negative correlation with age at all sites measured (high anal canal, r = -0.65, P <.001; middle anal canal, r = -0.49, P <.001; low anal canal, r = -0.21, P =.012). There was no significant correlation between age and thickness of subepithelial tissue, longitudinal muscle, or puborectalis muscle. Subjects whose internal sphincter showed mixed echogenicity were significantly older than those whose internal sphincter was uniformly hypoechoic (mean, 47.4 vs 34.6 years; P <.001). Subjects with mixed internal sphincter echogenicity also had a significantly thinner external sphincter at high (mean thickness, 3.8 vs 4.6 mm; P <.001) and middle (mean thickness, 3.7 vs 4.1 mm; P =.03) anal canal levels. CONCLUSION: At older ages there are increased internal anal sphincter thickness and decreased external anal sphincter thickness. Diagnosis of external sphincter atrophy on the basis of sphincter thinning requires that one distinguish between abnormal thinning and age-related differences.

Adult↗

Short-term effects of sacral nerve stimulation for idiopathic slow transit constipation.

This study assessed the short-term clinical and physiological effect of continuous sacral nerve stimulation in patients with slow transit constipation. Some patients with idiopathic slow transit constipation are unresponsive to conservative treatments, while colectomy has a variable and poorly predictable outcome. Sacral nerve stimulation is a less invasive and reversible procedure that enables direct neuromodulation of the pelvic floor and hindgut. It has been used successfully in the treatment of urologic disorders and fecal incontinence, and some of these patients with concurrent constipation have also noted improved stool frequency and rectal evacuation. Eight women (median age 47 years, median symptom duration 31 years, median stool frequency once per 6 days) were implanted with a temporary percutaneous stimulating S3 electrode for 3 weeks, attached to an external stimulator (Medtronic, Minneapolis,USA). A bowel symptom diary card, anorectal physiological studies, and a radiopaque marker transit study were completed before and during stimulation. Two patients had cessation or marked diminution of symptoms, including normalization of bowel frequency. Colonic transit did not return to normal in any patient. Rectal sensory threshold to distension was decreased during stimulation. Percutaneous temporary sacral nerve stimulation symptomatically improved a minority of patients with resistant idiopathic slow transit constipation. Sensory function was altered by stimulation. Further studies are required to identify patients who may benefit and to assess a range of stimulation parameters.

Adult↗