Induction of epidermal and hepatic ornithine decarboxylase by a Prudhoe Bay crude oil

Application of a Prudhoe Bay crude oil (PBCO) to the backs of mice caused a rapid induction of epidermal ornithine decarboxylase (ODC). A maximum induction of over 60-fold was seen at 6 hr after application of 50 microliters of PBCO. Concurrently, epidermal putrescine levels were elevated 4.7-fold over controls. Intraperitoneal administration of PBCO led to a 15-20-fold increase in hepatic ODC activity but to a 45% decrease in the renal enzyme activity. Maximum induction of ODC was seen at 12 hr following the administration of 4 ml/kg body wt of PBCO. Hepatic putrescine levels were elevated 34-fold over controls. Pretreatment of mice with the protein synthesis inhibitor cycloheximide abolished both epidermal and hepatic ODC induction.

Relationship of chemical structures of anthraquinones with their effects on the suppression of immune responses

A series of 37 anthraquinones were evaluated for their ability to inhibit the induction of cytolytic T-lymphocytes in a mixed lymphocyte culture system, useful as a preliminary screen for immunosuppressive agents. These compounds were also tested for their ability to prevent the production of antibody in mice. It was demonstrated that 1,4-bis [(2-aminoethyl)amino]-5, 8-dihydroxy-9,10-anthracenedione dihydrochloride (AEAD, 2) derived from mitoxantrone (MX, 1) by removing hydroxyethyl groups from both side chains was extremely active in depressing immune responses in vitro and in vivo. Four additional anthraquinones related to AEAD were also identified to share similar suppressive activity. They include a Schiff base, 1,4-dihydroxy-5,8-bis[[2-[(3-pyridinylmethylene)amino]ethyl]amino] -9,10-anthracenedione; a dimer with N-terminals methylated, 1,1-[ethylenebis (iminoethyleneimino)]-bis [5,8-dihydroxy-4-[(2-methylamino-ethyl)amino] anthraquinone tetrahydrochloride; an oxazolidine, 1,4-dihydroxy-5,8-bis [[2-(2-propyl-3-oxazolidinyl)ethyl]amino] anthraquinone; and its polymeric oxazolidine, poly [5,8-dihydroxy-1,4-anthraquinonyleneiminoethylene-3,2-oxazolidine- diyltrimethylene-2,3-oxazolidinediylethyleneimino]. These compounds may warrant further consideration as candidates for the treatment of refractory autoimmune diseases and in organ transplantation.

Stimulation of enzyme secretion from isolated pancreatic acini by Clostridium difficile toxin B

Exposure of isolated rat pancreatic acini to increasing concentrations (10 ng - 800 ng/ml) of toxin B from Clostridium difficile produced a biphasic effect on the rate of secretion of amylase, trypsinogen, and chymotrypsinogen. Whereas doses of toxin B from 10-30 ng/ml increased enzyme secretion by 15-20%, doses between 30 ng and 60 ng/ml showed a regression of this effect, whereafter the rate of secretion of amylase, trypsinogen, and chymotrypsinogen increased with increasing concentrations of the toxin. Toxin B concentration of 800 ng/ml enhanced amylase, trypsinogen and chymotrypsinogen secretion by 119%, 185% and 195%, respectively, when compared with the basal level. Stimulation of enzyme secretion by toxin B was not affected by the presence of either actinomycin-D or cycloheximide, at a concentration which inhibited acinar RNA or protein synthesis by 80-90%. Although toxin B as well as CCK8, carbachol and secretin by themselves caused significant stimulation in amylase, trypsinogen and chymotrypsinogen secretion from isolated pancreatic acini, toxin B together with either CCK8, carbachol or secretin produced no further augmentation in enzyme secretion than what was observed with the secretagogues alone. It is concluded that toxin B of Cl. difficile exerts a direct effect on pancreatic acinar cells as evidenced by stimulation of enzyme secretion.

Total parenteral nutrition catheter sepsis: impact of the team approach

For a period of 32 months from the inception of the Parenteral and Enteral Nutrition (PEN) Team at the University of Michigan, the infection rate (IR) related to central venous catheters (CVCs) for total parenteral nutrition (TPN) was prospectively evaluated. Six hundred twenty-two catheters were placed in 377 patients for a total of 9,200 patient days. The length of CVC stay ranged from 2 to 108 days with a mean of 14.5. CVC longevity was longer on units where certification of nurses by the PEN team was mandatory (mean 20.4 days, IR 3.5%) vs comparable units which utilized informal instruction (mean 14.4 days, IR 3.5%). Twenty-two catheters led to patient sepsis for a rate of 3.5%, or 2.39 CVC-related infections per 1000 patient days. The preteam infection rate was 24.0%, as determined by a 6-month prospective study. Infection rates for CVCs used for TPN only and those used for parenteral nutrition (PN) plus blood products, antibiotics, and CVP measurements were identical, 3.5%. The team approach can effectively increase PN catheter longevity and reduce infection rates. Conservative cost accounting of best and worst case scenarios determined a range of $3,700 to $8,900 per episode of catheter sepsis.

The mechanism of action of 3,6-bis(2-piperidinoethoxy)acridine trihydrochloride (CL 246,738) in the potentiation of natural killer cells

An effort has been made to determine the mechanism by which the immunomodulator 3,6-bis(2-piperidinoethoxy)acridine trihydrochloride (CL 246,738) enhances the cytotoxic activity of natural killer (NK) cells. Orally administered CL 246,738 produced augmentation of NK cell activity in mice in a dose-related fashion over a dose range of 10 to 160 mg/kg, with a peak stimulation occurring at 40 mg/kg. The stimulatory effect was short-lived and only persisted for 3 days after a single oral dose of the drug. However, it could be boosted by a subsequent treatment. With anti-asialo GM-1 (anti-ASGM-1) antibody used as an NK cell marker, it was determined that the compound increased the number of ASGM-1-positive cells in mice, as indicated by radioimmunoassay and immunofluorescence staining. NK cells of beige mice were also activated by CL 246,738. Furthermore, the compound at concentrations of 0.02 to 0.2 microgram/ml induced NK cell activity in vitro, with a minimum 3-day incubation being required for optimal activation. This effect was dependent on the presence of macrophages and was inhibited by anti-IFN-alpha + beta but not anti-IFN-beta antibody. Taken together, it is postulated that the compound functions by stimulating macrophages to release IFN-alpha, which subsequently activates NK cells. As an effective stimulator of IFN and NK cells, CL 246,738 may prove clinically useful in the immunotherapy of certain types of malignancy.

The mechanism of action of 3,6-bis(2-piperidinoethoxy)acridine trihydrochloride (CL 246,738) in the potentiation of natural killer cells

An effort has been made to determine the mechanism by which the immunomodulator 3,6-bis(2-piperidinoethoxy)acridine trihydrochloride (CL 246,738) enhances the cytotoxic activity of natural killer (NK) cells. Orally administered CL 246,738 produced augmentation of NK cell activity in mice in a dose-related fashion over a dose range of 10 to 160 mg/kg, with a peak stimulation occurring at 40 mg/kg. The stimulatory effect was short-lived and only persisted for 3 days after a single oral dose of the drug. However, it could be boosted by a subsequent treatment. With anti-asialo GM-1 (anti-ASGM-1) antibody used as an NK cell marker, it was determined that the compound increased the number of ASGM-1-positive cells in mice, as indicated by radioimmunoassay and immunofluorescence staining. NK cells of beige mice were also activated by CL 246,738. Furthermore, the compound at concentrations of 0.02 to 0.2 microgram/ml induced NK cell activity in vitro, with a minimum 3-day incubation being required for optimal activation. This effect was dependent on the presence of macrophages and was inhibited by anti-IFN-alpha + beta but not anti-IFN-beta antibody. Taken together, it is postulated that the compound functions by stimulating macrophages to release IFN-alpha, which subsequently activates NK cells. As an effective stimulator of IFN and NK cells, CL 246,738 may prove clinically useful in the immunotherapy of certain types of malignancy.

Malignant hypertension and asymmetric septal hypertrophy in a 43-year-old black man

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Inhibition of the induction of alloreactivity with mitoxantrone

A clinically active anticancer agent, mitoxantrone (MX): 1, 4-dihydroxy-5,8-bis[[2-[(2-hydroxyethyl)amino]ethyl]amino]-9, 10-anthracenedione dihydrochloride, was studied for its potential inhibitory effect on alloreactivity induction. Addition of MX to mixed lymphocyte cultures (MLC) not only inhibited the proliferative response of lymphocytes to alloantigens but also prevented the generation of cytolytic T lymphocytes (CTL). MX showed a long-lasting effect in vitro and acted at the inductive rather than the effector phase of the CTL response as indicated by its failure to alter the activity of those CTL already generated in MLC. MX also inhibited CTL induction in mice. However, the precursors of CTL appeared to be spared in these animals as supported by limiting dilution analysis and also because CTL could be reactivated by exposure of splenocytes to the same or different alloantigens in MLC. The present findings demonstrate that MX is a potent immunosuppressive agent and as such might prove to be clinically useful in the treatment of autoimmune diseases or find utility in the organ transplantation field.

Malakoplakia of the urinary tract

The authors report 4 cases of urinary tract malakoplakia. This rare disease of unknown etiopathogenesis can present with a benign character in the bladder, but when the upper urinary tract is affected, loss of renal function can occur. Treatment aims to control the primary infection, as well as enhance intracellular bactericidal activity, which seems to be compromised in these cases. Cytoreductive surgery may be indicated when this treatment fails.

Depression, urinary free cortisol excretion and lymphocyte function

An impairment in lymphocyte response to mitogen stimulation, a correlate of cell-mediated immunity, has been reported in patients with depressive illness. To investigate whether such impairment in lymphocyte function is related to excessive secretion of cortisol, an immunosuppressive hormone, we compared mitogen-induced lymphocyte proliferation in three groups of subjects: depressed patients with elevated 24-hour urinary free cortisol (UFC) excretion; depressed patients with normal UFC excretion; and normal controls. Depressed patients in both groups showed significant reductions in lymphocyte mitogenic activity, in comparison with the normal controls, but the two depressive groups did not significantly differ from each other in their lymphocytic responses to any of the mitogens used. Furthermore, no significant correlations were found, within depressed patients, between UFC excretion and lymphocyte mitogenic responses. Depression is therefore associated with an impairment in lymphocyte function that cannot be explained solely on the basis of increased cortisol secretion.

Etretinate therapy reduces polymorphonuclear leukocyte chemotaxis--enhancing properties of psoriatic serum

Using a Boyden chamber technic, we measured the directed chemotaxis of polymorphonuclear leukocytes obtained from control subjects or psoriasis patients when the leukocytes were placed in sera obtained from control subjects or psoriasis patients. The samples from patients were obtained before therapy and after 2 and 4 weeks of etretinate administration. Compared with control sera, the sera from seven untreated psoriasis patients significantly enhanced the chemotaxis of polymorphonuclear leukocytes from control subjects toward a chemotaxin (p less than 0.05). After 4 weeks of etretinate therapy, the chemotaxis-stimulating ability of the sera from psoriasis patients was no longer significantly greater than that of the control sera. This decline in the chemotaxis-stimulating activity of our patients' sera preceded significant clearing of their psoriasis. The levels of circulating etretinate in the blood of our patients could not account for the reduction. Etretinate therapy had no apparent direct effect on the chemotactic activity of polymorphonuclear leukocytes from the psoriasis patients but may act in part by reducing the inflammatory effects of psoriatic sera.

Acute pancreatitis

The exocrine pancreas secretes into the gut on demand more than 20 proteins that are indispensable for digestion. In-vivo autodigestion is prevented by an array of natural safeguards. In acute pancreatitis, inappropriate intrapancreatic activation and release of pancreatic hydrolases occur, but the pathogenetic mechanism of autodigestion is unclear. The release of proteases, lipase and colipase, phospholipase A, vasoactive peptides, and other agents probably accounts for the edema, tissue destruction, fat necrosis, metabolic abnormalities, and complications. Ethyl alcohol abuse, gallstones, trauma, and other common and rare conditions can induce pancreatitis. The patient's outcome can be predicted by certain prognostic signs. Ultrasonography and computerized tomography are invaluable diagnostic tools and magnetic resonance imaging appears promising. Hemodynamic monitoring, intensive care with colloid and crystalloid infusions, correction of electrolyte abnormalities, judicious use of antibiotics, peritoneal lavage, drainage of pancreatic exudation fluids, and surgical intervention require a team approach, especially in patients with multiple complications. Additional research is needed into the pathogenetic mechanism of autodigestion and the design of specific therapies.

Candida berkhout species isolated from deep-seated and superficial candidosis. Classification of species with the N. van Uden and H. Buckley key

The purpose of the present paper is to improve the understanding of the incidence of Candidosis in human infections. 85 species of Candida isolated from deep-seated and superficial Candidosis were studied. Identification was attained using the key of N. van Uden & H. Buckley (22).

Treatment of antibiotic-associated colitis with vancomycin

Sixty-five patients were treated with oral vancomycin for Clostridium difficile colitis associated with treatment of infection by antibiotics. Colitis was confirmed by endoscopy in patients with diarrhoea and positive tests on diarrhoeal stools for Cl. difficile and/or its cytotoxin or, if endoscopy could not be performed, by the presence of fever and peripheral or faecal leucocytosis. Vancomycin dosage ranged from 125 to 500 mg four times daily for an average of about ten days. The mean duration of diarrhoea after starting therapy was four days; abdominal pain and fever usually resolved in two or three days. Post-treatment carriage of Cl. difficile was common. Eighteen per cent of patients developed a recurrence of colitis after treatment was discontinued, but responded to treatment with oral vancomycin, metronidazole, or bacitracin. After comparison of our results with those reported by others we concluded that vancomycin remains the treatment of choice for patients who are acutely and severely ill with Cl. difficile.

Resistance of Aeromonas hydrophila to beta-lactam antibiotics

The activity of some beta-lactam antibiotics upon 20 strains of Aeromonas hydrophila and some properties of their beta-lactamases have been studied. High degree of resistance to benzylpenicillin and lower resistance to ampicillin and cephaloridine was observed. Clavulanic acid showed the highest activity. When clavulanic acid was assayed at subinhibitory concentrations in association with ampicillin. MICs of the latter decreased to two- to eight-fold. All strains produced inducible beta-lactamases with high activity upon ampicillin. A group of cephalosporinase-like enzymes was also found. Some beta-lactamases were inhibited by cloxacillin, and most of them were completely inhibited by 5 mg/l of clavulanic acid. Low impermeability of Aerom. hydrophila cells to beta-lactams was observed.

Clinical competence certification: a critical appraisal

The American Board of Internal Medicine has requested that residency program directors certify the clinical competence of their candidates. The clinical evaluation exercise (CEX) is one component of the overall certification process. During 1980-1982, 120 residents at the University of Michigan Hospitals participated in a CEX. The results show recurrent inadequacies among the residents in eliciting the social and family histories and performing the mental status and neurologic examinations. The ability to elicit a complete medical history correlated (p less than .01) with communication skills. In three of four specific organ examinations, the ability to perform a technically correct and complete physical examination correlated with the accuracy of the residents' findings (p less than .05). Separate evaluations by senior faculty members generally did not correlate with the residents' performance on the CEX. Analysis of the program described here showed that it requires considerable faculty time, requires training of evaluators to develop interrater reliability, and raises questions as to the validity of the CEX. As national certification boards integrate a formal clinical component into the certification process, such problems need to be addressed and rectified.

Transfer factor in the treatment of carcinoma of the lung

From 1976 to 1982, 63 patients with carcinoma of the lung underwent curative pulmonary resection, mediastinal lymph node dissection, and postoperative mediastinal irradiation when indicated. After operation, the patients were randomized by cell type and stage of disease into two groups. Beginning 1 month postoperatively, Group 1 patients (N = 28) received 1 ml of transfer factor that had been extracted from the blood of normal individuals. Subsequent doses were administered at 3-month intervals. Group 2 patients (N = 35) served as controls. There were no significant differences between the two groups with respect to age, sex, extent of resection, histological cell type, or stage of disease. Twenty of the 28 treated patients were alive and free from disease from 7 to 77 months after treatment, whereas 17 of the 35 control patients were free from disease. The 1-year survival for Group 1 was 84% and for Group 2, 81%. The 2-year survival was 78% for Group 1 and 46% for Group 2 (p = 0.045). The survival rates by stage of disease were as follows: Stage I, 15 out of 17 or 88% in Group 1 and 15 out of 23 or 65% in Group 2 (p = 0.097); Stages II and III, 5 out of 11 or 45% in Group 1 and 3 out of 12 or 25% in Group 2 (p = 0.304). The results of the study suggest that the administration of transfer factor to patients who have undergone pulmonary resection for carcinoma of the lung can have a significant impact on the prolongation of life.

Effect of therapy with latamoxef (moxalactam) on carriage of Clostridium difficile

Twenty-seven patients receiving latamoxef (moxalactam) as a single antimicrobial agent were studied prospectively for Clostridium difficile carriage and development of diarrhoea or colitis. Stools were available prior to therapy from only seven patients, one of whom (14.3%) was an asymptomatic carrier. None of twelve patients studied during therapy were carriers. Seven of 27 patients (25.9%) were colonized with Cl. difficile after completion of latamoxef therapy, and three patients had cytotoxin positive stools. Two patients with cytotoxin grew Cl difficile from stools and one patient was culture negative. Only one patient, who had both culture and cytotoxin positive stools, had profuse diarrhoea. Cl. difficile clinical isolates were only moderately susceptible to latamoxef in vitro. Hamsters given moxalactam developed caecitis. Patients receiving latamoxef, or third generation cephalosporins, may be at increased risk of development of Cl. difficile associated diarrhoea and should be followed closely for this complication, especially after therapy has been discontinued.

Colonization of central venous catheters

We studied etiologic factors important in colonization of 179 central venous catheters (CVCs) in patients randomized into group 1 (who received daily topical applications of povidone-iodine) or group 2 (who received only dry dressing changes). Colonization rates of CVC tips were similar between group 1 (18/84 or 21%) and group 2 (22/95 or 23%). Peripheral blood cultures grew Candida in eight hyperalimented patients (evenly divided between groups 1 and 2), S epidermidis in four other patients (also evenly divided), and gram-negative bacteria in three patients. Colonization rates for CVCs in place for 0 to seven days was 15.6% (17/109) and 76.7% (23/30) if used from eight to 30 days. Inflammatory signs at CVC sites were often absent when CVCs became colonized or produced bacteremia. Unimportant determinants of CVC colonization included skin securement of CVCs, antibiotic infusions through CVC lines, and masking and gowning of physicians before CVC placement. Daily applications of povidone-iodine did not reduce colonization of CVCs as compared to dry dressing changes.

Inciting and etiologic agents of colitis

Since 1979, 3,115 stool samples were tested for detection of Clostridium difficile and its cytotoxin; these were obtained from patients who had drug-related diarrhea. Presumed or proven colitis due to C. difficile was diagnosed in 130 patients. Drugs implicated most commonly as causing or associated with the onset of enterocolitis due to C. difficile were ampicillin (38 episodes), cephalosporins (71), clindamycin (36), and the aminoglycosides (45). The hamster model of colitis was employed to explore the role of other inducing agents. Altering the usual diet of hamsters to one with a higher protein content decreased the time to death due to C. difficile cecitis following the administration of cefazolin (10 mg). Several cathartics also were studied for their effect on the lethality of antibiotic-induced cecitis. Daily administrations of castor oil (0.5 ml per day) and vegetable oil (1.0 ml per day) improved survival against lethal doses of clindamycin. Milk of magnesia or mineral oil provided no protection. Four patients with C. difficile colitis induced by therapy with cytotoxic drugs also were identified. Methotrexate induced cecitis when administered orally and daily to hamsters, and C. difficile and its cytotoxin were identified in the hamsters' stools. Death due to methotrexate-induced cecitis was prevented by daily administration of folinic acid or vancomycin. These data demonstrate that a variety of antibiotics, antineoplastic agents, cathartics, and diet changes can induce C. difficile colitis in humans and hamsters.

Effects of subinhibitory antibiotics on bactericidal activity of chronic granulomatous disease granulocytes in vitro

Experiments were performed on leukocytes from patients with chronic granulomatous disease (CGD), incubated with subinhibitory concentrations of antibiotics (clindamycin, methicillin and N-demethyl-lincomycin). Results indicate a minor enhancement of bactericidal activity. This improvement occurred in both CGD homozygotes and one heterozygote and may indicate a future role for the use of low dose antibiotics to augment immune defences such as granulocyte function.

Disseminated histoplasmosis, invasive pulmonary aspergillosis, and other opportunistic infections in a homosexual patient with acquired immune deficiency syndrome

A homosexual man with the acquired immune deficiency syndrome had an unusually wide array of opportunistic infections. Despite antibiotic treatment over a period of two and a half years, the patient died. Perianal herpetic ulcers, oral candidiasis, cytomegalovirus infection, and disseminated infections with both Histoplasma capsulatum and Mycobacterium avium-intracellulare were diagnosed during illness. An autopsy revealed invasive pulmonary aspergillosis and a cerebellar lesion caused by cytomegalovirus. The latter was probably responsible for the patient's gait disturbance.

Differential susceptibility of Aeromonas hydrophila and Enterobacteriaceae to nalidixic acid

The susceptibility of 49 strains of Aeromonas hydrophila and 77 strains of Enterobacteriaceae towards nalidixic acid was compared by tube dilution and agar diffusion methods. A higher susceptibility was exhibited by Aerom. hydrophila and no overlap in MICs was found for strains of the two groups of microorganisms. Discs containing 0.25 microgram of nalidixic acid produced measurable zones of growth inhibition with Aerom. hydrophila and no zones with the Enterobacteriaceae. The use of a disc with 0.25 microgram of nalidixic acid for the primary differentiation of strains of Aerom. hydrophila from those of the Enterobacteriaceae with similar biochemical properties is suggested.

Impaired lymphocyte function in depressive illness

Mood states and immunity may be related. To investigate the immune status of patients with primary depressive illness, we compared in-vitro lymphocytic responses to three different mitogens in 26 drug-free depressed patients and 20 normal controls of comparable age and sex. We observed a generalized and marked decrease in the lymphocyte mitogenic activity among the depressive group. This defect in lymphocyte function may be indicative of an impairment in cell-mediated immunity in patients with primary depressive illness.

Rifampin and pseudomembranous colitis

Isolates of toxigenic Clostridium difficile, the most frequent cause of antibiotic-associated pseudomembranous colitis, are almost always highly susceptible to rifampin. However, resistant isolates exist and have been associated with colitis in both hamsters and humans given rifampin. Rifampin is rarely implicated in the disease in humans; only six cases have been documented, all in elderly patients receiving treatment for tuberculosis. At least three of these patients had liver disease, and all six had also received one or more other antimicrobial agents. The only isolate of C. difficile from these patients that was studied was resistant to rifampin. The colitis was usually mild and responsive to discontinuation of treatment with rifampin or to oral treatment with vancomycin.

Fluorescent-antibody test for detection of Clostridium difficile in stool specimens

We evaluated a direct fluorescent-antibody test to detect Clostridium difficile, the most frequent cause of antibiotic-associated colitis. C. difficile organisms were injected into the ear veins of New Zealand White rabbits to induce antibodies, and the globulin fractions of their sera were conjugated to fluorescein isothiocyanate. The resulting conjugate strongly stained all 40 isolates of C. difficile tested. It also stained isolates of C. sordellii, C. bifermentans, C. chauvoei, and C. sporogenes, but not 20 other clostridial isolates or 10 isolates from other species. Results of testing fecal smears with the direct fluorescent-antibody method were compared with results of testing stools for C. difficile toxin and of culturing for C. difficile on a selective medium. A total of 158 fecal specimens from patients with antibiotic-associated diarrhea were tested. In these patients, the fluorescent-antibody test agreed with culture and toxin testing in 93% of the specimens. However, in normal adults, 62% of the fecal specimens from which C. difficile could not be cultured were positive by the fluorescent-antibody test. Absorption of the conjugate with C. sordellii led to a loss of reactivity to other clostridia as well as to 18 of 20 isolates of C. difficile.

Computerized house officer schedules at the University of Michigan

An economical, computerized system was developed for producing the annual schedule of monthly assignments for medical house officers. This program can generate schedules that conform to the individual preferences of the house officers while meeting the requirements of the residency program. As a result, more individual requests of the house officers are granted than under the previous manual system. Besides providing these direct benefits, the system ensures that house officers are assigned to each rotation according to their appropriate level of skill.

Clostridium difficile colitis associated with cancer chemotherapy

Administration of cancer chemotherapeutic agents to humans and animals is frequently complicated by diarrhea and enterocolitis. Clostridium difficile and its toxin were found in the stools of two patients with colitis after chemotherapy for malignant neoplasms. Diarrhea in both patients resolved with oral vancomycin hydrochloride therapy. Clostridium difficile was also isolated from several fomites within the room of one of these patients and also from the hands of his nurses. Based on these two recent experiences, we believe patients with cancer and diarrhea or signs suggestive of colitis should be studied for toxigenic C difficile and appropriate isolation techniques employed.

Antibiotic-associated pseudomembranous colitis: an epidemiologic investigation of a cluster of cases

Ten cases of antibiotic-associated colitis (AAC) were identified at a hospital in Washington, D.C., from March 17 to May 9, 1979. No geographic clustering of cases was found, nor was an association with increased use of antibiotics demonstrated. Exposure to aminoglycosides, cephalosporins, and clindamycin was associated with AAC, as was a history of enemas in the seven days before the onset of illness (P=0.045). This association was strengthened when gastrointestinal procedures-defined as (1) three or more enemas per week, (2) the insertion of a nasogastric tube for two or more days, or (3) gastrointestinal surgery-were performed within seven days of the onset of illness (P=0.007). Clostridium difficile was not isolated from the hospital environments, nursing personnel, or family members of the patients. C. difficile was isolated from stool specimens of five (36%) of 14 patients who served as controls.

Suppression of Clostridium difficile by normal hamster cecal flora and prevention of antibiotic-associated cecitis

Administration of normal cecal homogenates decreased numbers of viable Clostridium difficile and prevented cecitis in antibiotic-challenged hamsters. Cecal anaerobes appeared to suppress C. difficile.

Treatment of Clostridium difficile colitis and diarrhea with vancomycin

Toxigenic Clostridium difficle is the major cause of antibiotic-associated colitis and is susceptible to vancomycin at fecal concentrations achieved with oral therapy. The effect of oral vancomycin was studied in 16 patients with C. difficile-related diarrhea or colitis, 12 of whom had colitis documented by endoscopy, biopsy, and/or barium enema. Four patients had antibiotic-associated diarrhea and possibly antibiotic-associated colitis, because sigmoidoscopy either showed normal results (two patients) or was not performed (two patients). Nineteen episodes of diarrhea were treated with oral vancomycin in two dosage regimens for three to 14 days. Twelve patients received 2 g daily, and four patients initially received 1 g or less per day. Within 48 hours of the start of vancomycin therapy, 14 of 16 patients (87 percent) showed a decrease in temperature, abdominal pain and diarrhea. Diarrhea ceased completely within two days of the start of vancomycin in nine episodes, within three to seven days in six episodes, and within eight to 14 days in the remaining four episodes, and within eight to 14 days in the remaining four episodes. Diarrhea recurred in two of these patients (12 percent) when the drug inciting the initial episode of colitis was given again 42 days or more after vancomycin therapy was stopped; both patients responded again to retreatment with vancomycin. Oral vancomycin is an effective treatment of C. difficile-related colitis and diarrhea.

Inhibitors of monocyte responses to chemotaxins are present in human cancerous effusions and react with monoclonal antibodies to the P15(E) structural protein of retroviruses

Individuals with cancer have previously been shown to have abnormal chemotactic responsiveness. Surgical removal of the tumor often resulted in normalization of monocyte function, which suggests that human neoplasms might inhibit monocyte chemotaxis by release of soluble mediators. We therefore examined the effects of cancerous effusions on monocyte polarization, i.e., the rapid change in monocyte morphology from round to a triangular "motile" configuration in response to chemoattractants. All 17 malignant effusions, representing 15 tumor types, inhibited monocyte polarization induced by the chemoattractant N-formyl-methionyl-leucyl-phenylalanine by 45-89% (mean 55.9 +/- 12.7%, P less than 0.01) in blinded assays. None of 17 benign effusions signigicantly inhibited polarization (0-15%, mean 6.2 +/- 4.2%). Dilutions of cancerous effusions as low as 1:200 produced inhibition that was time, temperature, and dose dependent . Monocyte polarization induced by activated serum or by chemotactic lymphokine was also blocked by cancerous effusions. The inhibitory activity affected the monocyte directly, and did not destroy the chemoattractant or block the polarization of granulocytes to chemotactic factors. High pressure liquid chromatography of five cancerous fluids revealed three peaks of inhibitory activity: greater than or equal to 200,000, 46,000 +/- 13,000, and 21,000 +/- 3,000 daltons. Fractionation of noncancerous effusions revealed only small amounts of the highest molecular weight inhibitory activity. The inhibitory activity in cancerous effusion was heat stable (56 degrees C, 30 min), trypsin sensitive, and could be absorbed by three different monoclonal antibodies reactive to P15(E), a structural component of type C retroviruses. In contrast, six monoclonal antibodies with other specificities had no effect on the inhibitors of polarization. This study demonstrates that human cancerous effusions contain novel proteins that are potent inhibitors of monocyte function and that are recognized by antibodies reactive to the P15(E) component of retroviruses. By producing such factors, tumor cells may subvert monocyte-mediated surveillance.

Evaluation of eight cephalosporins in hamster colitis model

Eight commonly used cephalosporins were evaluated in the hamster colitis mode. They were all found to cause hemorrhagic cecitis and death within 10 days of being given as subcutaneous or oral challenges. Necropsy findings were indistinguishable from clindamycin-induced cecitis. Bacteria-free cecal filtrate obtained from hamsters dying of cephalosporin-induced cecitis contained toxin similar or identical to hat produced by Clostridium difficile isolated from the cecum of a hamster. Daily oral administration of poorly absorbed cephalosporins protected hamsters from clindamycin-induced cecitis and death as long as the cephalosporins were continued. The absorbable cephalosporins were ineffective in protecting hamsters from clindamycin-induced cecitis. This difference probably relates to the lower concentrations of absorbable cephalosporins maintained in the ceca of the hamsters. The possible correlation of these findings to human cases of cephalosporin-induced pseudomembranous colitis is discussed.

Epidemiology of antibiotic-associated colitis; isolation of Clostridium difficile from the hospital environment

Clostridium difficile is the most important cause of antibiotic-associated colitis. Using selective media, it was found that contamination with this organism was common in the environment of patients in the hospital with the disease. It was often found on floors, hoppers, toilets, bedding, mops, scales and furniture. This organism was also present on these items, but less often, in areas in which patients known to carry this hardy spore-forming organism had not been detected. Air, food and walls were negative. The organism was isolated from the hands and stools of asymptomatic hospital personnel. It was also found on surfaces in a patient's home. The importance of the various sources of the organism in its spread in the hospital is not known, and further studies are needed. It is suggested that enteric isolation precautions, and careful handwashing and cleansing of potentially contaminated surfaces and objects may be worthwhile when cases of antibiotic-associated colitis are identified.