Clinical and immunological outcomes of HIV-exposed uninfected and HIV-unexposed uninfected children in the first 24 months of life in Western Kenya

BACKGROUND

Previous studies show increased morbidity in children who are HIV-exposed but uninfected (HEU) compared to children who are HIV-unexposed uninfected (HUU). We sought to evaluate the effects of prenatal HIV exposure on clinical and immunological outcomes in the first 24 months of life.

METHODS

Eighty-five HEU and 168 HUU children from Kenya were followed from birth to 24 months. All mothers living with HIV received combination antiretroviral therapy. Children who were HEU received standard-of-care cotrimoxazole prophylaxis through 18 months. Episodes of acute illness were identified through a combination of active and passive follow up. Trajectories of plasma cytokines, vaccine-specific antibodies, and antimalarial antibodies were examined.

RESULTS

Children who were HEU and children who were HUU had similar growth curves. Children who were HEU had lower rates of malaria (rate ratio 0.54, 95% CI 0.38, 0.77) and respiratory illness (rate ratio 0.80, 95% CI 0.68, 0.93). Trajectories of plasma cytokines and vaccine-specific antibodies were similar in children who were HEU and HUU. There were subtle differences in antimalarial antibody dynamics, in which children who were HEU had overall lower antibody levels against five of the 14 malaria antigens tested.

CONCLUSIONS

Children who were HEU and born to optimally treated mothers living with HIV had similar growth characteristics and immune profiles compared to children who were HUU. Children who were HEU had reduced risk for malaria and respiratory illness, which may be secondary to cotrimoxazole prophylaxis.

Clinical and Immunological Outcomes of HIV-Exposed Uninfected and HIV-Unexposed Uninfected Children in the First 24 Months of Life in Western Kenya

Background

Previous studies show increased morbidity in children who are HIV-exposed but uninfected (HEU) compared to children who are HIV-unexposed uninfected (HUU). We sought to evaluate the effects of prenatal HIV exposure on clinical and immunological outcomes in the first 24 months of life.

Methods

Eighty-five HEU and 168 HUU children from Kenya were followed from birth to 24 months. All mothers with HIV received combination antiretroviral therapy. HEU children received standard-of-care cotrimoxazole prophylaxis through 18 months. Episodes of acute illness were identified through a combination of active and passive follow up. Trajectories of plasma cytokines, vaccine-specific antibodies, and antimalarial antibodies were examined.

Results

HEU and HUU children had similar growth curves. HEU children had lower rates of malaria and respiratory illness. Trajectories of plasma cytokines and vaccine-specific antibodies were similar in HEU and HUU children. There were subtle differences in antimalarial antibody dynamics, in which HEU children had overall lower antibody levels against five of the 14 malaria antigens tested.

Conclusions

HEU children born to optimally treated mothers living with HIV had similar growth characteristics and immune profiles compared to HUU children. HEU children had reduced risk for malaria and respiratory illness, which may be secondary to cotrimoxazole prophylaxis.

Reduced Transplacental Transfer of Antimalarial Antibodies in Kenyan HIV-Exposed Uninfected Infants

BACKGROUND

Altered neonatal immune responses may contribute to the increased morbidity observed in HIV-exposed but uninfected (HEU) infants compared with HIV-unexposed uninfected (HUU) infants. We sought to examine the effects of prenatal HIV and malaria exposure on maternal and neonatal plasma cytokine profiles and transplacental antibody transfer.

METHODS

Forty-nine HIV+ and 50 HIV- women and their HIV-uninfected neonate pairs from Kenya were assessed. All HIV+ mothers received combination antiretroviral therapy. Maternal plasma and cord blood plasma samples at delivery were tested for 12 cytokines, total IgG, and IgG specific to 4 vaccine antigens and 14 Plasmodium falciparum antigens.

RESULTS

HIV+ mothers had lower levels of all 12 plasma cytokines at delivery compared with HIV- mothers, but there were no differences between HEU and HUU neonates. There were no differences in the cord-to-maternal ratios (CMRs) of vaccine-specific IgG between HIV+/HEU and HIV-/HUU maternal-neonate pairs. HIV+/HEU maternal-neonate pairs had significantly lower CMRs for 3 antimalarial IgGs-merozoite surface protein 9, circumsporozoite protein, and erythrocyte binding antigen 181-which remained statistically significant after adjustment for malaria in pregnancy.

CONCLUSIONS

In a cohort of optimally treated HIV-infected pregnant women, maternal HIV infection was associated with reduced transplacental transfer of antimalarial antibodies.

Comparing dose prediction software used to manage gentamicin dosing

BACKGROUND

Current Australian guidelines recommend initiating directed therapy of gentamicin if administration exceeds 48 h. Directed doses of gentamicin require the monitoring of plasma concentrations of gentamicin to determine the 24-h area under the time course of plasma gentamicin concentrations (AUC) and a dosage prediction program, for example TCIWorks or Aladdin. However, doses calculated by such programs have not been compared with an established program.

AIM

To compare the directed dosage of gentamicin calculated by TCIWorks, Aladdin and an Excel-based program, with an established program, Abbottbase.

METHODS

Peak and trough plasma concentrations after the first and second administered doses of gentamicin were available from three patient groups (n = 20-23) with varying creatinine clearances (<40, 40-80, >80 mL/min). The directed dose needed to produce 24-h AUC values of 80 mg.h/L was calculated using each program.

RESULTS

There was a strong correlation between the directed doses predicted by each of the three programs compared with Abbottbase, following the first administered dose (r(2) > 0.97, P < 0.0001). The mean ratio (90% confidence intervals) of these directed doses of the gentamicin were: TCIWorks/Abbottbase 106% (105-107%), Aladdin/Abbottbase 102% (101-103%) and Excel/Abbottbase 108% (106-109%). The correlations and dose ratios were also similar when comparisons were made following the second administered dose. For each of the three renal function groups, all programs yielded similar directed doses.

CONCLUSIONS

The four programs used in the calculation of directed doses of gentamicin yielded similar results. Any would be suitable for use in clinical practice.

Structures of three inhibitor complexes provide insight into the reaction mechanism of the human methylenetetrahydrofolate dehydrogenase/cyclohydrolase

Enzymes involved in tetrahydrofolate metabolism are of particular pharmaceutical interest, as their function is crucial for amino acid and DNA biosynthesis. The crystal structure of the human cytosolic methylenetetrahydrofolate dehydrogenase/cyclohydrolase (DC301) domain of a trifunctional enzyme has been determined previously with a bound NADP cofactor. While the substrate binding site was identified to be localized in a deep and rather hydrophobic cleft at the interface between two protein domains, the unambiguous assignment of catalytic residues was not possible. We succeeded in determining the crystal structures of three ternary DC301/NADP/inhibitor complexes. Investigation of these structures followed by site-directed mutagenesis studies allowed identification of the amino acids involved in catalysis by both enzyme activities. The inhibitors bind close to Lys56 and Tyr52, residues of a strictly conserved motif for active sites in dehydrogenases. While Lys56 is in a good position for chemical interaction with the substrate analogue, Tyr52 was found stacking against the inhibitors' aromatic rings and hence seems to be more important for proper positioning of the ligand than for catalysis. Also, Ser49 and/or Cys147 were found to possibly act as an activator for water in the cyclohydrolase step. These and the other residues (Gln100 and Asp125), with which contacts are made, are strictly conserved in THF dehydrogenases. On the basis of structural and mutagenesis data, we propose a reaction mechanism for both activities, the dehydrogenase and the cyclohydrolase.

Novel cryptophycin antitumor agents: synthesis and cytotoxicity of fragment "B" analogues

A general synthetic approach to novel cryptophycin analogues 6 is described. N-Hydroxysuccinimide active ester 15, a key common intermediate, was converted to beta-epoxide 6 in three steps, via initial coupling with unprotected amino acid 9, followed by deprotection/macrolactamization of acyclic precursor 16, and final oxidation of styrene 7 to install the C7-C8 beta-epoxide. Cryptophycin styrenes 7 and beta-epoxides 6, bearing diverse side chains in fragment "B", were evaluated for cytotoxic activity. beta-Epoxides 6, in general, were significantly more potent than the corresponding alpha-epoxides 17 and styrenes 7. A benzyl side chain was required for potent activity, with beta-epoxide 6u, possessing a 3-Cl,4-(dimethylamino)benzyl moiety, as the most potent cytotoxic agent prepared, with an IC(50) = 54 pM, only 2-fold less than that of Cryptophycin-52 (3).

Disposition and metabolism of the sulfonylurea oncolytic agent LY295501 in mouse, rat, and monkey

The disposition and metabolism of LY295501 was studied in mice, rats, and monkeys. This novel diaryl sulfonylurea oncolytic agent is structurally related to sulofenur and shows excellent activity in a broad range of mouse antitumor models. The compound is well absorbed, giving plasma concentrations greater than 200 micrograms/ml after oral doses of 30-100 mg/kg, where it appears to be completely bound (> 99.9%) to plasma proteins. The high degree of protein binding may be a factor in its relatively long half-life, which ranges from about 8 hr in rats and 15 hr in mice to 50 hr in monkeys. While more material was excreted in feces than in urine from mice and rats given single oral doses of [14C]LY295501, urine was the major route of elimination in monkeys. Three major metabolites-all formed via oxidation of the saturated part of the benzodihydrofuran moiety-were characterized in the urine of mice, rats, and monkeys. It is interesting that two of these metabolites are derived from opening of this saturated ring, an unusual metabolic process which represents a significant part of the metabolism of LY295501. As with sulofenur, metabolites of 3,4-dichloroaniline formed after metabolic cleavage of the sulfonylurea linkage were also found in urine. Unlike sulofenur, these do not seem to have major toxicological significance, but their formation does explain the minor methemoglobinemia observed in toxicology studies of LY295501. Even though only trace amounts of LY295501 were found in urine, LY295501 is the predominant drug-related material in plasma, along with small amounts of other, relatively nonpolar, metabolites.

Sulfonimidamide analogs of oncolytic sulfonylureas

A series of sulfonimidamide analogs of the oncolytic diarylsulfonylureas was synthesized and evaluated for (1) in vitro cytotoxicity against CEM cells, (2) in vivo antitumor activity against subaxillary implanted 6C3HED lymphosarcoma, and (3) metabolic breakdown to the o-sulfate of p-chloroaniline. The separated enantiomers of one sulfonimidamide analog displayed very different activities in the in vivo screening model. In general, several analogs demonstrated excellent growth inhibitory activity in the 6C3HED model when dosed orally or intraperitoneally. A correlative structure-activity relationship to the oncolytic sulfonylureas was not apparent.

Studies on the mechanism of phosphatidylinositol 3-kinase inhibition by wortmannin and related analogs

Wortmannin, a fungal metabolite, was identified as a potent inhibitor (IC50 = 4.2 nM) of phosphatidylinositol 3-kinase (PI 3-kinase). Due to the importance of PI 3-kinase in several intracellular signaling pathways, structure-activities studies on wortmannin analogs were performed in an effort to understand the structural requirements necessary for PI 3-kinase inhibition. Since wortmannin is an irreversible inhibitor of PI 3-kinase, it was postulated that covalent attachment at the electrophilic C-21 site was a possible mode of action for PI 3-kinase inhibition. We have prepared various wortmannin analogs which address the possibility of this mechanism. Of particular interest are compounds which affect the C-21 position of wortaminnin either sterically or electronically. Our results support the conclusion that nucleophilic addition by the kinase onto the C-21 position of wortmannin is required for inhibition of PI 3-kinase by wortmannin analogs. Additionally, we have prepared several D-ring analogs of wortmannin, and their activities are reported herein. We conclude that the wortmannin D ring is an important recognition site since modifications have such a dramatic effect on inhibitor potency. Finally, the identification of 17beta-hydroxywortmannin represents the first reported subnanomolar inhibitor of PI 3-kinase. These studies, along with in vivo antitumor experiments, suggest that the mechanism of PI 3-kinase inhibition correlates to the associated toxicity observed with wortmannin-based inhibitors of PI 3-kinase.

Cyclosporin A monitoring in Australia: consensus recommendations

Cyclosporin-A (CsA) therapeutic drug monitoring plays an integral role in therapeutic management of immunosuppressed patients, including those with organ transplants. This communication, prepared by an Australian team, presents recommendations for the routine monitoring of CsA, including blood sampling methodological approaches and interpretation of results generated. The consensus approach described is intended to address the diversity of attitudes to CsA monitoring demonstrated in a recent national survey of Australian laboratories that provide CsA analyses.

Mucinous carcinoma--just another colon cancer?

The significance of mucinous carcinoma has been controversial since first described by Parham in 1923. Previous reports have suggested that mucinous tumors affect young patients, involve the more proximal colon, are more advanced at diagnosis, and have a poorer prognosis than nonmucinous colon carcinoma. More recent reports have refuted these results. In an effort to clarify the significance of mucinous histology, a retrospective review of cases of invasive colon cancer treated at the Ochsner Clinic between 1982 and 1985 was undertaken. Mucinous adenocarcinoma, as defined by > or = 50 percent mucin, was found in 52 patients. During the same period, 343 nonmucinous adenocarcinomas were resected. The mean age, distribution within the colon, stage at diagnosis, and survival of mucinous carcinoma patients were compared with those with nonmucinous tumors. Mucinous tumors presented at a statistically significant more advanced stage (38 percent vs. 22 percent Dukes C lesions; P < 0.01). No significant differences were seen in age at presentation, distribution within the colon, or stage-for-stage survival when the entire group was analyzed. Mucinous carcinomas of the rectum occurred at an advanced stage more frequently (P < 0.05) than nonmucinous rectal carcinomas and had a markedly worse five-year survival (11 percent vs. 57 percent; P < 0.002).

Ogilvie's syndrome: colonoscopic decompression and analysis of predisposing factors

Forty-eight cases of Ogilvie's syndrome, colonic pseudo-obstruction, presenting between 1983 and 1989 were retrospectively reviewed to assess the results of colonoscopic decompression and to identify potential etiologic factors. Three patients had spontaneous resolution with medical treatment. Forty-five patients required 60 colonoscopic decompressions: 38 (84 percent) were successfully treated using colonoscopy; five (11 percent) required an operation; and two died within 48 hours of colonoscopy from medical causes. No complications or deaths were the result of colonoscopy. Twenty-nine patients (64 percent) were successfully treated with a single colonoscopy. One-third of patients required serial decompressions. Average cecal diameter in patients with successful colonoscopic decompression was 12.4 cm but was larger for patients requiring more than one colonoscopy (13.3 cm) and for those who failed colonoscopic therapy (13.4 cm). The spine or retroperitoneum had been traumatized or manipulated in 52 percent of patients. Patients with Ogilvie's syndrome were being treated with narcotics (56 percent), H-2 blockers (52 percent), phenothiazines (42 percent), calcium-channel blockers (27 percent), steroids (23 percent), tricyclic antidepressants (15 percent), and epidural analgesics (6 percent) at diagnosis. Electrolyte abnormalities included hypocalcemia (63 percent), hyponatremia (38 percent), hypokalemia (29 percent), hypomagnesemia (21 percent), and hypophosphatemia (19 percent). Colonoscopic decompression in Ogilvie's syndrome is safe and effective management. Multiple pharmacologic and metabolic factors, as well as spinal and retroperitoneal trauma, appear to alter autonomic regulation of colonic function, resulting in colonic pseudo-obstruction.

Rectal carcinoids: the most frequent carcinoid tumor

One hundred seventy patients with gastrointestinal carcinoid tumors were treated at Ochsner Clinic from 1958 to 1990. Ninety-four rectal carcinoid tumors were diagnosed and treated during this time. Carcinoid tumors of the rectum represented the most frequent primary site (55 percent), followed by carcinoids of the ileum (12 percent), appendix (12 percent), colon (6 percent), stomach (6 percent), jejunum (2 percent), pancreas (2 percent), and other (5 percent). One-half of rectal carcinoids were discovered during anorectal examination of asymptomatic patients. The remainder were found primarily by examination of patients for symptoms of benign anorectal conditions. The diagnosis of rectal carcinoid was made at the time of initial examination in 61 patients. This allowed definitive treatment in a single session by local excision and fulguration in 48 patients. The remainder were treated by repeat biopsy and fulguration (25 patients) or by transanal excision (12 patients). Overall, 85 carcinoid tumors of the rectum measuring less than 2 cm were treated by local excision and fulguration or by transanal excision, with an average five-year follow-up. There were no local recurrences. Ten patients with metastasizing rectal carcinoids averaging 4 cm were treated. All were symptomatic at presentation and fared poorly despite radical surgery. Three were alive at three years but only one survived five years. At our institution, rectal carcinoids were the most frequently detected carcinoid tumor. Small carcinoids of the rectum were adequately treated by local excision and fulguration or by transanal excision, with no local recurrence. The true incidence of rectal carcinoids is detected only with careful and complete rectal examination of the asymptomatic screening population by experienced surgeons. With more widespread screening of the well population, rectal carcinoids may become recognized as the most frequent human carcinoid tumor.

Improved high-performance liquid chromatographic method for the determination of indomethacin in plasma

Indomethacin is an inhibitor of prostaglandin synthesis and has several uses, including the ability to encourage closure of a patent ductus in premature neonates. A rapid, accurate, and sensitive high-performance liquid chromatographic (HPLC) method is described for measuring plasma concentrations of indomethacin. An acidic buffer (citrate, pH 3.0) was employed to alter the pH of the aqueous phase prior to extraction to minimise interference interference from endogenous compounds. Extraction of indomethacin from plasma was optimally achieved with petroleum ether (boiling fraction of 40-60 degrees C):dichloromethane (50:50). However, separation of indomethacin from plasma proteins was attempted unsuccessfully using acetonitrile precipitation; severe band broadening occurred due to injected sample solvent problems. The absolute recoveries for indomethacin and internal standard (mefenamic acid) were over 90% (n = 3). Precision was expressed as the coefficient of variation (n = 4), which was less than or equal to 8% at each of six indomethacin concentrations in the range 50-2,000 ng/ml. The limit of quantitation of indomethacin in plasma was 50 ng/ml (0.5 ml of plasma injected). We report an HPLC method for the quantitation of indomethacin in plasma that may have widespread applicability for routine drug assay laboratories.

Diminutive colonic polyps: an indication for colonoscopy

A prospective study investigated the significance of solitary diminutive colonic polyps discovered during screening flexible sigmoidoscopy. Eighty-two patients with a solitary diminutive polyp (less than or equal to 5 mm) underwent colonoscopy after cold biopsy of the index polyp. Of the patients with adenomatous index polyps, 42.5 percent had proximal neoplastic polyps. Of the patients with hyperplastic index polyps, proximal neoplastic polyps were found in 38.9 percent. These data suggest that diminutive polyps identified during flexible sigmoidoscopy, whether adenomatous or hyperplastic, place the patient in the intermediate risk group for colorectal neoplasia. We recommend that any patient with polyps seen during screening sigmoidoscopy, regardless of histopathology, should undergo colonoscopy.

Calcified mucocele of the appendix presenting as ureteral obstruction

Mucocele of the appendix, a rare lesion, occurs in 0.3% of patients undergoing appendectomy. Only 46 cases of calcified mucocele have been reported. Complications reported include appendiceal intussusception, rupture resulting in acute abdomen, and infection. We report the case of a 74-year-old man with a calcified mucocele of the appendix that was discovered in the evaluation of a ureteral obstruction. During exploratory surgery, the patient was found to have a 6 x 5 cm appendiceal tumor and underwent a right ileocolectomy. Pathologic examination showed calcified mucous cystadenoma of the appendix. Calcification of a mucocele is believed to denote chronicity. Our case is the first report of ureteral obstruction secondary to calcified mucocele and the second calcified mucocele to be seen on computerized tomography. Calcified mucocele should be included in the differential diagnosis of any calcified tumor in the right lower quadrant.

Complications associated with ileal pouch-anal anastomosis

Seventy-three patients underwent total colectomy, rectal mucosectomy, creation of J or S ileal reservoir, and ileal pouch-anal anastomosis from 1982 to 1989. Mean follow-up was 38 months, with a minimum of 3 months in 15 patients being followed long-term at another institution. Forty-eight (66%) patients had histologically proven ulcerative colitis and 25 (34%) patients had familial polyposis. Thirty-eight J reservoirs and 35 S reservoirs were constructed. There were no perioperative deaths. The failure rate (loss of pouch) was 3%. Thirty-six complications in 34 (47%) patients were reported, 14 (19%) patients required surgery. Bowel obstruction was the most common postoperative complication (16%), followed by pouchitis (15%), and cuff infection (5%). Seventy-eight percent of the complications were associated with the J pouch. Average stool frequency at 1 year was 4 per 24-hour period. Other complications included postoperative pneumonia (1), peroneal nerve palsy (1), and temporary sexual dysfunction (1). Seven of 15 complications requiring surgical intervention occurred in the first 2 years of the study period, illustrating the learning curve associated with the procedure. Blood loss, transfusion requirements, and length of operation were not associated with higher complication rates. Use of the J pouch and experience of the individual surgeon affected morbidity.

Digoxin-like immunoreactivity in serum from neonates and infants reduced by centrifugal ultrafiltration and fluorescence polarization immunoassay

We evaluated the TDx Digoxin II (Abbott) modified procedure for interference from digoxin-like immunoreactive factors (DLIF) in pediatric patients. The effectiveness of centrifugal ultrafiltration as a means of removing DLIF interference from the serum of such patients was assessed. We used sera from 40 patients who had not received digoxin, whom we divided into two age groups: 30 neonates (less than 34 days postpartum) and 10 infants (younger than six months). Digoxin-like immunoreactivity was detected in 34 of 41 (83%) neonatal specimens (range 0.2-1.0 micrograms/L) and 16 of 25 (60%) infants' specimens (range 0.2-1.3 micrograms/L). Centrifugal ultrafiltration of serum specimens from these patients reduced but did not eliminate the DLIF interference in some specimens. A comparison of concentrations of DLIF in serum with various other patients' characteristics demonstrated a strong correlation (r = 0.915; P = 0.0001) between DLIF and serum bilirubin in the infants. Apparent digoxin concentrations from 19 serum and serum ultrafiltrate samples collected from 13 patients (four neonates and nine infants) who were treated with digoxin showed a good correlation (r = 0.97); however, the serum samples showed a positive bias of 0.39 microgram/L. We conclude that the TDx Digoxin II modified procedure is still subject to considerable DLIF interference in these two pediatric populations. This interference can be reduced in some serum specimens, but cannot be eliminated completely as others reported.

Colonoscopic screening of asymptomatic patients with a family history of colon cancer

The records of 201 asymptomatic patients who underwent colonoscopy based solely on a family history of colon cancer were reviewed. Eighty-five patients (42 percent) had a total of 166 lesions. Fifty-four (27 percent) patients of the screened population had neoplastic lesions, while 31 (15 percent) patients had nonneoplastic polyps. Four carcinomas were found. Twenty-five of the patients with polyps (29 percent) had no polyps distal to the splenic flexure; these proximal polyps (and two carcinomas) would have been missed on screening with fiberoptic sigmoidoscopy. Nineteen of these 25 patients had polyps smaller than 0.5 cm, which likely would have been missed with contrast enemas. Almost one half (47 percent) of all polyps discovered at screening colonoscopy were proximal to the descending colon. Only one patient younger than 40 years old had adenomas. The yield of polyps and cancer in patients with familial risk indicates screening colonoscopy should be considered after age 40.

Usefulness of performing colonoscopy one year after endoscopic polypectomy

This retrospective study defines a population with neoplastic colonic polyps who have had colonoscopic polypectomy and, in follow-up within one year, a repeat colonoscopic evaluation. The population was broken down into two groups, one group that had polyps at the second examination and one group that did not. This study determined which factor(s) were significant among this population in distinguishing whether new polyps would be found at one year follow-up. The authors found that among the many variables studied, only polyp multiplicity was significant in predicting polyp recurrence. More than one polyp found at index colonoscopy led to a significant chance of having a new polyp after only one year. Also, it was demonstrated that these "new" polyps were unlikely to have been "missed" polyps from the initial colonoscopy. Because of the shifting location, smaller size, and fewer instances of histologic atypia in these polyps compared with those at index examination, the authors believe that polyps found after one year may be assumed to have arisen de novo. Finally, the authors show that a significant number of polyps occur beyond the reach of the flexible sigmoidoscope (approximately 60 cm). The authors recommend that patients who have polyps undergo a colonoscopic examination. When patients are re-evaluated after having colonoscopic neoplastic polypectomy, they should undergo repeat colonoscopy.

Surgical management of anorectal fistulas in Crohn's disease

A retrospective review of patients with Crohn's disease treated at our institution from 1973 to 1986 revealed 35 patients operated upon for anorectal fistulas. Twenty-nine had low intermuscular fistulas (multiple in seven), and six had high intermuscular (supralevator) fistulas. Fistulotomy alone was performed in 19 patients, and eight underwent partial fistulotomy and seton insertion. Five additional patients had proximal fecal diversion before fistulotomy. Three patients with severe colonic and anorectal disease underwent proctocolectomy as the initial procedure. Of the 32 patients who had fistulotomy performed, complete healing occurred in 30. Seven patients who healed required more than one operation for fistula. One patient was left with an asymptomatic fistula, and one required proctectomy for persistent symptomatic fistula and proctitis. Success of operation correlated with absence of rectal disease and quiescent disease elsewhere in the gastrointestinal tract. Aggressive medical treatment is required to control bowel disease preoperatively. In the majority of patients, subsequent surgery is justified and healing can be anticipated.

Results of operation for rectovaginal fistula in Crohn's disease

A retrospective review of patients with Crohn's disease treated at our institution from 1973 to 1986 revealed 12 patients operated on for rectovaginal fistula. Disease involved the large intestine in 10 patients. Primary fistula repair was performed in four patients and four others had staged repair with preliminary fecal diversion. Four patients with severe colonic and anorectal disease had proctocolectomy performed as the first procedure. Of eight patients who underwent fistula repair, complete healing occurred in six. One patient has a persistent fistula, which is minimally symptomatic, and the other required proctocolectomy after three unsuccessful repairs. Success of operation correlated with quiescent intestinal disease and absence of rectal involvement. In selected patients with symptomatic fistulas, surgical repair is indicated and healing can be anticipated.

Classification of overdose/self-poisoning presentations to an accident and emergency department

A simple classification system of overdoses presenting to a hospital emergency department is described. Five major overdose categories were developed (accidental, suicidal behavior, recreational/experimentation, compulsive use, and an indeterminate category), which were divided into 10 subcategories. A prospective survey at an inner-city hospital in Sydney classified 199 consecutive self-poisoning presentations as being due to compulsive drug use in 38% of cases; suicidal gesture as a reaction to stress, 17%; adverse reactions to recreational or experimental use, 15%; suicidal gesture to influence others, 7%; genuine accident or noncompliance with medication, 6%; genuine suicide attempt, 3%; and pseudo-overdose, 3%. The reason for the overdose was uncertain in the remainder of the cases. Additional data are also presented, including the types of drugs involved in each overdose category. Categories of overdose may be useful in psychosocial assessment for follow-up interventions, assist in research, and help reduce negative attitudes toward overdoses.

Endometriosis of the bowel

One hundred sixty-three cases of endometriosis of the bowel (5.4% of 3037 laparotomies for endometriosis at the Ochsner Foundation Hospital) were reviewed to assess the management of this complication. Colon and rectal surgeons performed bowel resections of the colon in 30 cases and resections of the ileum and/or cecum in 11 cases. Gynecologic surgeons resected bowel implants, often multiple, in 153 patients, and also performed other necessary surgery, either ablative (with removal of uterus, tubes, and one or both ovaries; 58.8%) or conservative (with preservation of reproductive potential; 41.2%). The bowel mucosa was opened in 15% of implant resections. Complications included transient pulmonary febrile responses in 43%, two pelvic infections, and one hematoma. Ileus was not a problem, and there were no deaths. Resection of intestinal implants appears to be a safe procedure.

Drugs involved in self-poisoning: verification by toxicological analysis

During a two-month prospective survey in a metropolitan teaching hospital's accident and emergency department, 239 consecutive drug-related attendances (excluding admissions to hospital that were primarily alcohol related) were identified. This represented 2.6% of total attendances. Of the 199 patients who presented to hospital with self-poisoning, a biological specimen was obtained from 158 (79%) for toxicological analysis, thus providing reliable data on the drugs that were involved in the overdoses. The most common drug groups that were identified were barbiturate (51% of cases) and benzodiazepine (49%) agents, alcohol with other drugs (44%), cannabinoids (32%) and opiate analgesic drugs (25%). Quinalbarbitone and amylobarbitone (Tuinal) and oxazepam were the most common "single" preparations. The use of cannabis and alcohol and the use of several drugs concurrently were more common than in previously reported surveys of self-poisoning. Discrepancies between the purported drug consumption and the toxicological results were frequent; complete agreement occurred in only 35% of the cases. The TOXI-LAB system was an adequate method for toxicological analysis. However, for epidemiological studies an additional back-up method is recommended to verify the presence of some drugs such as barbiturate and benzodiazepine agents.

A potentially brighter prognosis for colon carcinoma in the third and fourth decades

In contrast to earlier studies that suggested that colon carcinoma is unusually lethal in the young, 69 patients, ages 20 to 39 years, had a relatively good prognosis. Fifty-nine percent lived over 5 years after diagnosis, and 51% were cured. Furthermore, 67% were cured if they did not have distant spread of the carcinoma at the time of the initial operation. Neither age, sex, tumor size, location, mere presence of lymph node metastases, depth of tumor invasion, nor predisposing disease of the colon was a strong prognostic factor. Metastases to six or more lymph nodes and distant spread of the tumor at the time of initial surgery were ominous findings. Mucinous carcinoma was relatively frequent (28%) and was also an ominous feature (only 5 of 20 patients cured as opposed to 26 of 43 with classical adenocarcinoma).

Cholelithiasis in ileostomy patients

A retrospective study of 152 ileostomates with inflammatory bowel disease (IBD) revealed that 16 patients (10.5 per cent) had diagnoses of cholelithiasis before, at the time of, or after having ileostomies. Of the remaining patients, 69 were followed for possible cholelithiasis, most of those with sonographic examination. Sixteen of this latter group of patients (23.2 per cent) were found to have cholelithiasis, usually in an asymptomatic stage. Among women over 50 years old, seven of 11 (63.6 per cent) had gallstones. Due to this high prevalence of cholelithiasis, gallbladder imaging is recommended as a part of the preoperative workup and follow-up of ileostomates. Prophylactic cholecystectomy may be carefully considered in female patients with IBD at the time of proctocolectomy.

Inflammatory bowel disease and cholelithiasis: the association in patients with an ileostomy

Sixty-nine patients were evaluated prospectively by sonography and history to determine the presence of cholelithiasis. Sixteen patients (23%) had a positive diagnosis. A control group was also prospectively evaluated. We have determined that patients above age 50 with a permanent ileostomy are at statistically significant risk of having cholelithiasis, and their risk is greater than that of a control group matched for age and sex. Radiologists should recognize this association and carefully evaluate the gallbladder of any patient with a permanent ileostomy who has abdominal pain.

High-performance liquid chromatographic analysis of diflunisal in plasma and urine: application to pharmacokinetic studies in two normal volunteers

A high-performance liquid chromatographic (HPLC) assay with fluorescence detection has been developed for the determination of diflunisal in plasma and urine. The plasma or urine, containing naproxen as the internal standard, was extracted with ether-hexane (1:1). The samples were analyzed on a microparticulate column, and the compounds were eluted using a mobile phase of 0.05 M phosphate buffer (pH 3) and methanol. Plasma samples were analyzed from two healthy male subjects who received a 250- and 750-mg oral dose of diflunisal 3 weeks apart. The data were analyzed according to a two-compartment open model. There was a disproportionate increase in the area under the plasma concentration-time curves (AUC 750 mg/AUC 250 mg was 3.84 for subject A and 4.22 for subject B) and a reduction in plasma clearance after the 750-mg dose of diflunisal. These data suggest that the kinetics of diflunisal may be dose dependent.

Guidelines for use of the flexible fiberoptic sigmoidoscope in the management of the surgical patient

Based on data from many clinical studies and programs, guidelines are presented for application of the flexible fiberoptic sigmoidoscope in the management of the surgical patient. The flexible fiberoptic sigmoidoscope has proved to be an instrument of extraordinary capability in detecting colorectal neoplasms with yields being two or three times greater than those of the rigid sigmoidoscope in the symptom-resolution, polyp and cancer surveillance patient categories. In addition, the practical advantages of the narrow diameter, flexibility, and length of the fiberoptic sigmoidoscope are readily appreciated when the surgeon finds that he can satisfactorily examine patients with rectal or sigmoid strictures, marked angulations, or contracted lumens in whom a rigid scope would be unsuitable. Data from the authors' comparative study of more than 3000 patients have permitted the development of not only guidelines for the application of the flexible fiberoptic sigmoidoscope but an appreciation of the modified role of the rigid sigmoidoscope and the proper relationship between the flexible fiberoptic sigmoidoscope and the flexible fiberoptic colonoscope. A most important consideration is based on data regarding the site distribution of 400 benign premalignant neoplasms detected in the comparative study. The even distribution of these lesions throughout the terminal 50 cm of colorectum underscores the need to examine as much of the colorectum as possible.

The pharmacokinetics and metabolism of 14C-carprofen in man

Three healthy male subjects received single 100 mg oral doses of carprofen containing 20 microCi of 14C-carprofen. Venous blood samples were drawn during the first 48 h after the dose and urine and faeces were collected for 120 h. Concentrations of carprofen and its metabolites in body fluids were determined by TLC and mass spectral analysis. After a lag time of 0.3 +/- 0.1 h (mean +/- S.D.), carprofen was absorbed rapidly and peak concentrations in the plasma were reached in 2.7 +/- 1.3 h. The 14C plasma concentrations declined in a biphasic fashion. The mean half-lives of the initial (alpha) and terminal (beta) phases were 1.1 h and 20.6 +/- 6.1 h, respectively. Biotransformation to a glucuronide metabolite appeared to be the major mechanism of carprofen clearance. In 48 h 74.0 per cent of administered radioactivity was recovered in urine and 14.1 per cent was recovered in faeces. A glucuronide of carprofen comprised 85.0 per cent of the radiolabelled compounds in urine. The remaining radioactivity was comprised of parent drug (12.0 per cent) and un unidentified acid-labile conjugate of the parent drug (3.0 per cent). This pattern of metabolism and excretion is different from that in the dog and rat and may explain species differences in drug activity and toxicity.

Colonic manifestations of collagen vascular diseases

Upper gastrointestinal manifestations of collagen vascular diseases have been well described. Recently our attention has been focused on the colonic complications: fibrosis and stricture resulting in obstruction, severe obstipation and recurrent fecal impactions secondary to pseudo-obstruction, progressive colonic dilatation resulting in gangrene of the colon, and sigmoid volvulus and diverticulitis in the presence of both wide- and narrow-mouth pseudodiverticula. Patients with these colonic manifestations of collagen vascular disease are disabled, if not severely ill. Recognition of the problem enables the surgeon to plan definitive surgical intervention ranging from segmental resection to total colectomy and ileoproctostomy to restore satisfactory large bowel function.

Comparison of transient ischemic colitis with that requiring surgical treatment

The records of 27 patients with colonic ischemia were reviewed. Twelve patients had typical reversible or transient ischemic colitis. Thirteen patients had an ischemic stricture or gangrene of the colon that required operation. Two of the patients have asymptomatic strictures of the splenic flexure and are under observation. The sigmoid colon in our series of patients was the most frequent area of symptomatic stricture formation. Any patient with ischemic colitis, especially that involving the sigmoid colon, should be observed closely for the development of a stricture. Surgical intervention is indicated only after colonoscopy and careful evaluation of symptoms and risk factors.

Vascular ectasias of the colon

Vascular ectasias are an acquired type of arteriovenous malformation distinct from neoplastic and congenital lesions. They can be the source of occult, recurrent or massive colonic bleeding usually in elderly patients but, occasionally, in younger adults. The vascular lesions are usually small but can be quite diffuse. The majority occurs in the right colon, but in our group of patients, a substantial number occurred distal to the hepatic flexure. The diagnosis can be made preoperatively, with colonoscopy but, more consistently, with arteriography. Therefore, arteriography should be performed in any patient with bleeding of the colon before surgical intervention. We recommend resection of the involved segment of the intestine as the treatment of choice.

Sigmoidoscopic examinations with rigid and flexible fiberoptic sigmoidoscopes in the surgeon's office: a comparative prospective study of effectiveness in 1,012 cases

The results obtained from 1,012 examinations in an on-going, cooperative study indicate that the overall yield provided by use of the flexible fiberoptic sigmoidoscope is 3.2 times greater than that of examinations with the rigid sigmoidoscope. More than twice (2.4 times) the number of polyps and more than three times the number of cancers were detected with the flexible fiberoptic sigmoidoscope. Experienced endoscopists can perform an examination with the flexible fiberoptic sigmoidoscope expeditiously in the office with minimal patient preparation, a high level of patient and physician acceptance, and relative safety when the usual mandatory colonoscopic precautions and guidelines are obeyed. The extraordinary advantages demonstrated by this study warrant wide clinical application of the flexible fiberoptic sigmoidoscope. We strongly recommend provision be made for appropriate training of physicians in the use of the instrument.