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Biomedical subjects

Joe J Tjandra

Publications and source records attributed to Joe J Tjandra.

At least 19 recordsLinked to original sources
PubMed2006

Preoperative chemoradiation for rectal cancer causes prolonged pudendal nerve terminal motor latency.

PURPOSE: A worsened anorectal function after chemoradiation for high-risk rectal cancer is often attributed to radiation damage of the anorectum and pelvic floor. Its impact on pudendal nerve function is unclear. This prospective study evaluated the short-term effect of preoperative combined chemoradiation on anorectal physiologic and pudendal nerve function. METHODS: Sixty-six patients (39 men, 27 women) with localized resectable (T3, T4, or N1) rectal cancer were included in the study. All patients received 45 Gy (1.8 Gy/day in 25 fractions) over five weeks, plus 5-fluorouracil (350 mg/m2/day) and leucovorin (20 mg/m2/day) concurrently on days 1 to 5 and 29 to 33. Patients who had rectal cancer with a distal margin within 6 cm of the anal verge had the anus included in the field of radiotherapy (Group A, n = 26). Patients who had rectal cancer with a distal margin 6 to 12 cm from the anal verge had shielding of the anus during radiotherapy (Group B, n = 40). The Wexner continence score, anorectal manometry and pudendal nerve terminal motor latency were assessed at baseline and four weeks after completion of chemoradiation. RESULTS: The median Wexner score deteriorated significantly (P < 0.0001) from 0 to 2.5 for both Groups A (range, 0-8) and B (range, 0-14). The maximum resting anal pressures were unchanged after chemoradiation. The maximum squeeze anal pressures were reduced (mean = 166.5-157.5 mmHg) after chemoradiation. This change was similar in both Groups A and B. Eighteen patients (Group A = 7, Group B = 11) developed prolonged pudendal nerve terminal motor latency after chemoradiation. These 18 patients similarly had a worsened median Wexner continence score (range, 0-3) and maximum squeeze anal pressures (mean = 165.5-144 mmHg). The results obtained were independent of tumor response to chemoradiation. CONCLUSIONS: Preoperative chemoradiation for rectal cancer carries a significant risk of pudendal neuropathy, which might contribute to the incidence of fecal incontinence after restorative proctectomy for rectal cancer.

Adenocarcinoma↗
PubMed2006

Injectable silicone biomaterial (PTQ) to treat fecal incontinence after hemorrhoidectomy.

PURPOSE: Passive fecal incontinence after hemorrhoidectomy may occur and is socially incapacitating. There has been no effective treatment for passive fecal incontinence caused by internal anal sphincter dysfunction. This case series reviewed the outcome of therapy with injectable silicone biomaterial (PTQ) in patients who had passive fecal incontinence after hemorrhoidectomy. METHODS: From 2003 to 2004, seven patients referred with passive fecal incontinence after hemorrhoidectomy (Milligan-Morgan hemorrhoidectomy n = 5; stapled hemorrhoidectomy n= 2) were treated with injectable PTQ implants. All were assessed with anorectal physiology testing, Wexner continence score, and objective quality of life questionnaires before and after treatment. RESULTS: The Wexner continence score improved significantly at three months (P= 0.016) after the injectable PTQ implant and continued to improve significantly for up to 12 months (P = 0.016). The global quality of life scores (Visual Analog Scale) showed similar improvement (P = 0.016 at 3 months; P = 0.016 at 12 months). Three domains (life style, coping behavior, and depression/self-perception) of Fecal Incontinence Quality of Life Scale were significantly improved. The manometric studies showed significant improvement in maximum resting anal canal pressures (P= 0.016) after the injectable PTQ implant. CONCLUSIONS: The injectable silicone biomaterial is an effective treatment for passive fecal incontinence after hemorrhoidectomy providing good medium-term improvement in fecal incontinence and fecal incontinence-related quality of life.

Adult↗
PubMed2006

Oral sodium phosphate (Fleet) is a superior colonoscopy preparation to Picopre (sodium picosulfate-based preparation).

PURPOSE: Small-volume bowel preparation is better tolerated than 4-liter polyethylene glycol lavage. However, the efficacy of various small-volume bowel preparation agents for colonoscopy has not been clearly defined. This randomized, controlled trial was designed to compare oral sodium phosphate (Fleet) with Picoprep (sodium picosulfate-based preparation). METHODS: Two hundred twenty-five outpatients, aged 65 years or younger, who would undergo colonoscopy by two endoscopists were randomized to receive two bottles of oral sodium phosphate or three sachets of Picoprep. A standardized questionnaire was completed by all patients and the endoscopists. The endoscopists were blinded to the preparation used. RESULTS: One hundred three patients were randomized to oral sodium phosphate (Fleet) (Group 1) and 122 patients to Picoprep (Group 2). Three patients were excluded because of colonic strictures. The groups were similar in age and gender, indications for colonoscopy, and previous colonic surgery. The quality of bowel cleansing in patients taking oral sodium phosphate (Fleet) was significantly better than Picoprep as assessed by the endoscopists (P = 0.0014). Both types of bowel preparation were associated with similar incidence of nausea (P = 0.4927), dizziness (P= 0.9663), abdominal cramps (P = 0.7157), and patient acceptability (P = 0.0767). Equal majority from either group would use the same bowel preparation again (91 percent of oral sodium phosphate (Fleet) and 93 percent of Picoprep group; P = 0.6172). Although Picoprep was better tasting (P = 0.0273), oral sodium phosphate (Fleet)was perceived to be a good preparation agent by a greater (although not significant) proportion of patients (P = 0.0853). CONCLUSIONS: Oral sodium phosphate (Fleet) is more effective in bowel cleansing than Picoprep as a bowel preparation agent. Both agents have similar side effects and patient acceptance.

Administration, Oral↗
PubMed2006

Preoperative loco-regional imaging in rectal cancer.

Preoperative staging of rectal cancer can influence the choice of surgery and the use of neoadjuvant therapy. This review evaluates the use of endorectal ultrasound (ERUS) and magnetic resonance imaging (MRI) in the local staging of rectal cancer. Staging for distant metastases is beyond the scope of this review. A MEDLINE search for published work in English between 1984-2004 was carried out by entering the key words of ERUS, MRI and preoperative imaging and rectal cancer. Initially, 867 articles were retrieved. Abstracts were reviewed and papers selected according to the inclusion criteria of a minimum of 50 patients and papers published in English. Papers focusing on preoperative chemoradiotherapy and distal metastases were excluded. Thirty-one papers were included in the systematic review. The examination techniques and images obtained are discussed and the respective accuracy is reviewed. ERUS and MRI have complementary roles in the assessment of tumour depth. Ultrasound has an overall accuracy of 82% (T1, 2, 40-100%; T3, 4, 25-100%) and is particularly useful for early localized rectal cancers. MRI has an accuracy of 76% (T1, 2, 29-80%; T3, 4, 0-100%) and is useful in more advanced disease by providing clearer definition of the mesorectum and mesorectal fascia. Both methods have similar accuracy in the assessment of nodal metastases. Ultrasound is more operator dependent and accuracies improve with experience, but it is more portable and accessible than MRI. Improvements in technology and increased operator experience have led to more accurate preoperative staging. ERUS and MRI are complementary and are most accurate for early localized cancers and more advanced cancers, respectively.

Endosonography↗
PubMed2005

The influence of specific luminal factors on the colonic epithelium: high-dose butyrate and physical changes suppress early carcinogenic events in rats.

INTRODUCTION: Although luminal delivery of butyrate is one putative mechanism by which biology of the colonic epithelium might be influenced by changes in luminal contents, there is a paucity of supportive cause-effect evidence. This study aimed to directly establish whether distal colonic butyrate delivery is able to alter the response of the distal colonic epithelium to a carcinogen. METHODS: Groups of male Sprague-Dawley rats with chronically intubated colons received infusions of 80 mM butyrate or 0.9 percent saline into distal colon two or five times daily. Three weeks after exposure to azoxymethane (15 mg/kg subcutaneously), the density of aberrant crypts was quantified in distal colon. RESULTS: Infusions of 0.5 ml twice daily, whether containing saline or butyrate, decreased the number of aberrant crypt foci by 45 percent compared with rats receiving no infusions (P = 0.004, analysis of variance). Similar results were obtained when infusions were restricted to the post-initiation phase. When infusions were increased to 1 ml five times daily, saline infusions similarly suppressed aberrant crypt formation (38 percent), but butyrate infusions suppressed it to a greater degree (by 64 percent; P = 0.02 compared with saline infusion, t-test). CONCLUSIONS: High levels of butyrate delivery to the distal colonic lumen alter the epithelial response to a carcinogen in otherwise healthy rats. This finding directly supports the notion that the effects of butyrate on cells in vitro do occur in vivo provided a sufficient dose is delivered. The effect of infusion of liquid per se on the epithelial response highlights the potential impact physical changes alone can have on the colonic epithelium.

Animals↗
PubMed2005

Practice parameters for the management of rectal cancer (revised).

The American Society of Colon and Rectal Surgeons is dedicated to assuring high-quality patient care by advancing the science, prevention, and management of disorders and diseases of the colon, rectum, and anus. The Standards Committee is composed of Society members who are chosen because they have demonstrated expertise in the specialty of colon and rectal surgery. This Committee was created to lead international efforts in defining quality care for conditions related to the colon, rectum, and anus. This is accompanied by developing Clinical Practice Guidelines based on the best available evidence. These guidelines are inclusive, and not prescriptive. Their purpose is to provide information on which decisions can be made, rather than dictate a specific form of treatment. These guidelines are intended for the use of all practitioners, health care workers, and patients who desire information about the management of the conditions addressed by the topics covered in these guidelines. It should be recognized that these guidelines should not be deemed inclusive of all proper methods of care or exclusive of methods of care reasonably directed to obtaining the same results. The ultimate judgment regarding the propriety of any specific procedure must be made by the physician in light of all of the circumstances presented by the individual patient.

Adenocarcinoma↗
PubMed2005

Practice parameters for the treatment of perianal abscess and fistula-in-ano (revised).

The American Society of Colon and Rectal Surgeons is dedicated to assuring high-quality patient care by advancing the science, prevention, and management of disorders and diseases of the colon, rectum, and anus. The Standards Committee is composed of Society members who are chosen because they have demonstrated expertise in the specialty of colon and rectal surgery. This Committee was created to lead international efforts in defining quality care for conditions related to the colon, rectum, and anus. This is accompanied by developing Clinical Practice Guidelines based on the best available evidence. These guidelines are inclusive, and not prescriptive. Their purpose is to provide information on which decisions can be made, rather than dictate a specific form of treatment. These guidelines are intended for the use of all practitioners, health care workers, and patients who desire information about the management of the conditions addressed by the topics covered in these guidelines. It should be recognized that these guidelines should not be deemed inclusive of all proper methods of care or exclusive of methods of care reasonably directed to obtaining the same results. The ultimate judgment regarding the propriety of any specific procedure must be made by the physician in light of all of the circumstances presented by the individual patient.

Abscess↗
PubMed2005

Practice parameters for the surgical treatment of ulcerative colitis.

The American Society of Colon and Rectal Surgeons is dedicated to assuring high-quality patient care by advancing the science, prevention, and management of disorders and diseases of the colon, rectum, and anus. The Standards Committee is composed of Society members who are chosen because they have demonstrated expertise in the specialty of colon and rectal surgery. This committee was created to lead international efforts in defining quality care for conditions related to the colon, rectum, and anus. This is accompanied by developing Clinical Practice Guidelines based on the best available evidence. These guidelines are inclusive, and not prescriptive. Their purpose is to provide information on which decisions can be made, rather than dictate a specific form of treatment. These guidelines are intended for the use of all practitioners, health care workers, and patients who desire information about the management of the conditions addressed by the topics covered in these guidelines. It should be recognized that these guidelines should not be deemed inclusive of all proper methods of care or exclusive of methods of care reasonably directed to obtaining the same results. The ultimate judgment regarding the propriety of any specific procedure must be made by the physician in light of all of the circumstances presented by the individual patient.

Colectomy↗
PubMed2005

Proteomic analysis of colorectal cancer: discovering novel biomarkers.

Colorectal cancer is one of the most common cancers in the Western world. When detected at an early stage, the majority of cancers can be cured with current treatment modalities. However, most cancers present at an intermediate stage. The discovery of sensitive and specific biomarkers has the potential to improve preclinical diagnosis of primary and recurrent colorectal cancer, and holds the promise of prognostic and therapeutic application. Current biomarkers such as carcinoembryonic antigen lack sensitivity and specificity for general population screening. This review aims to highlight the role of current proteomic technologies in the discovery and validation of potential biomarkers with a view to translation to the clinic.

Biomarkers, Tumor↗
PubMed2004

Carbohydrate-electrolyte (E-Lyte) solution enhances bowel preparation with oral fleet phospho-soda.

PURPOSE: Bowel preparation with oral sodium phosphate can cause symptomatic dehydration and electrolyte disturbances. This randomized, controlled trial was designed to evaluate whether carbohydrate-electrolyte (E-Lyte) solution enhanced bowel preparation and improved patient acceptance with oral sodium phosphate. METHODS: A total of 187 consecutive adults undergoing colonoscopy by two endoscopists were randomized to receive two packets of oral sodium phosphate (Fleet Phospho-soda) with or without additional supplement of a carbohydrate-electrolyte (E-Lyte) solution. All patients and endoscopists completed a standardized questionnaire. Urine-specific gravity and serum biochemistry were randomly performed in 150 and 50 patients, respectively. RESULTS: Ninety patients were randomized to have oral sodium phosphate with E-Lyte supplements (Group 1) and 94 patients to sodium phosphate without E-Lyte supplements (Group 2). The groups were similar in age and gender, indication for colonoscopy, and previous colonic surgery. Patients taking E-Lyte supplement had significantly less dizziness (none, 80 vs. 56 percent; P < 0.001) and a trend toward less nausea (none, 70 vs. 56 percent; P = 0.05). All patients in Group 1 completed the bowel preparation as opposed to 3 percent of Group 2 being unable to complete the preparation. Hypokalemia was significantly more frequent ( P = 0.008) in Group 2 patients without E-Lyte supplements. More patients in Group 2 needed intravenous rehydration (11 vs. 4 percent). Differences in serum creatinine and urine-specific gravity suggested possibly a lesser degree of hypovolemia in patients taking E-Lyte supplements. The quality of bowel cleansing in patients taking E-Lyte supplements was considered better by both the endoscopists and patients. CONCLUSIONS: Carbohydrate-electrolyte (E-Lyte) solution protects against hypokalemia, improves patient tolerability, and may enhance use of oral sodium phosphate as a bowel-preparation agent.

Administration, Oral↗
PubMed2004

Intermediate conductance potassium (IK) channels occur in human enteric neurons.

IK channels, which had been previously found in hemopoetically derived cells (including erythrocytes and lymphocytes) and epithelial cells, where they regulate proliferation, cell volume regulation and secretion, have only recently been discovered in neurons, where they had previously been claimed not to occur. Based on immunohistochemical detection of IK channel-like immunoreactivity, it has been reported that IK channel expression in enteric neurons is suppressed in Crohn's disease. In the present work we have investigated whether authentic IK channels are expressed by enteric neurons. Human and mouse tissue was investigated by immunohistochemistry, Western blot and RT-PCR. Immunohistochemical studies revealed IK channel-like immunoreactivity in large myenteric neurons, but not in other cell types in the external muscle layers. Many of these nerve cells had calbindin immunoreactivity. Western blots from the external muscle revealed an immunoreactive band at the molecular weight of the IK channel. Using RT-PCR, we detected a transcript corresponding to the IK channel gene in extracts from the ganglion containing layer. The sequence obtained from the RT-PCR product was identical to that previously published for the IK channel. We conclude that IK channels are expressed by human enteric neurons, including large smooth surfaced neurons that are possibly the human equivalent of the Dogiel type II neurons that express these channels in small mammals.

Adult↗
PubMed2004

How safe is adjuvant chemotherapy and radiotherapy for rectal cancer?

Over the last three decades, a series of clinical trials have led to the use of adjuvant pelvic radiotherapy and chemotherapy in high-risk (T3-4 or N1) rectal cancer. There is a need to improve patient selection in order to identify the group most at risk for recurrent disease. The toxicity of adjuvant therapy should be factored into this consideration. The optimal sequencing of adjuvant therapy before or after surgery, the use of short- or long-course radiotherapy, and the utility of concurrent chemotherapy is currently being examined in randomized controlled trials (RCTs). The aim of this report was to review the morbidity and mortality in all RCTs of adjuvant therapy for rectal cancer.

Antineoplastic Agents↗
PubMed2004

Sacral nerve stimulation: an emerging treatment for faecal incontinence.

Faecal incontinence is common, distressing to the patient and socially incapacitating. The treatment options depend on the severity and aetiology of incontinence. For mild cases of faecal incontinence, medical management and pelvic floor physiotherapy may be adequate. For more severe cases, surgery is often required. Patients who have a distinct sphincter defect are amenable to surgical repair. In many cases, there is a combination of diffuse structural damage of the anal sphincters with pudendal neuropathy. Conventional surgical repairs have a modest degree of success and the results tend to deteriorate with time. Neosphincter procedures such as artificial bowel sphincter and dynamic graciloplasty are potentially morbid and technically complex. Sacral nerve stimulation is innovative and has had a medium-term success with improvement of quality of life in over 80% of patients treated for faecal incontinence. These results are superior to other techniques in treating patients with severe refractory faecal incontinence, where current maximal therapy has failed. The technique is unique because there is a screening phase, which has a high predictive value. It is also associated with minimal complications that are usually minor. However, most published reports of sacral nerve stimulation for treatment of faecal incontinence were case studies and methods of assessing outcome were variable. Criteria for patient selection are evolving and are yet to be defined. The present paper critically reviews the publications to date on sacral nerve stimulation for treatment of faecal incontinence. This will form the basis for future evaluation of this emerging treatment of severe, intractable faecal incontinence. Randomized clinical trials like that of the Melbourne trial will further clarify the role and indications of sacral nerve stimulation for faecal incontinence.

Electric Stimulation Therapy↗
PubMed2003

Optimizing the outcome for patients with rectal cancer.

INTRODUCTION: Historically, rectal cancer with transmural spread and/or lymph node involvement has presented a major challenge to surgeons, with a variable and often high risk of local recurrence and poor survival outcomes. In recent years a large amount of literature has focused attention on the importance of surgical technique, tumor staging, and the optimal integration of CT and radiation therapy. METHODS: This article reviews the clinical trials that have defined the current approach to rectal cancer, the controversies regarding what should be considered the standard of care, and the ongoing clinical studies that will resolve some of these issues. RESULTS: The preoperative staging of rectal cancer can be improved with the use of endorectal ultrasound and (where available) magnetic resonance imaging. Careful pathologic analysis, particularly of the radial margin, provides important prognostic information that enables better allocation of postoperative care. Although both radiation therapy and CT have a proven role in adjuvant therapy, the interpretation of many studies is confounded by unacceptably poor outcomes in the control arm, and in older studies the use of inferior chemotherapy and radiation therapy techniques. Ongoing studies will better define the optimal combination and timing of chemotherapy and radiation therapy, with respect to both toxicity and survival endpoints. CONCLUSIONS: A combined modality approach to rectal cancer, integrating the colon and rectal surgeon, pathologist, medical oncologist, and radiation oncologist, is necessary to achieve optimal outcomes. The achievements to date and the ongoing vigorous debates regarding standard care continue to highlight the importance of quality ongoing research in a rapidly changing clinical environment.

Colectomy↗
PubMed2002

Development of a chronic colonic intubation model in rats for the study of luminal factors in colonic diseases.

INTRODUCTION: A rat model of long-term colonic intubation has been developed to facilitate the in vivo study of colonic biology. This study aims to characterize this model. METHODS: The effects of intubation and sham surgery on animal behavior and weight gain were measured and compared with unoperated controls. The reproducibility of the model was assessed by comparing complication and failure rates for three operators. The distribution and excretion of infused materials were studied using radiology and gas chromatography of feces, respectively. The effects of the colonic tube and infusions on the mucosa were assessed histologically. RESULTS: There was about 10 percent weight loss postoperatively, more marked in those rats undergoing more extensive surgery. Subsequent weight gain was similar in all groups, and no behavioral effects of surgery were noted. There were no differences in histologic appearances or proliferative indices among the groups. All three operators had similar complication and tube dislodgement rates. Radiologic examination showed even distribution of infusate regardless of fecal consistency. Infusion through the two tubes allowed the cecum and the distal bowel to be targeted differentially. The infusions did not alter the consistency of the fecal pellets or induce defecation. Gas chromatography at various time points after butyrate infusion showed a small, but statistically insignificant, rise in fecal excretion, representing less than 10 percent of the infused butyrate. CONCLUSIONS: A highly reproducible in vivo rat model, with an experimental life span of five to six weeks, has been achieved. Biological agents can be accurately delivered via the colonic tubes and are retained in the colonic segment of interest. This intubation model should provide a valuable tool in the future for in vivo studies of colonic biology.

Animals↗