Comparative efficacy of DMP 840 against mouse and human solid tumor models

BACKGROUND

DMP 840 is a compound from a class of bis-naphthalimide antitumor agents that recently completed Phase I clinical trials at three North American centers and is currently undergoing Phase II testing. Preclinically, it was shown to have curative activity against a variety of human tumor xenograft models.

PURPOSE

To test DMP 840 both in vitro and in vivo for antiproliferative activity against predominantly mouse tumor models.

METHODS

A disk diffusion soft agar colony formation assay was used to determine the in vitro growth inhibitory activity against a selection of mouse and human tumor cell lines, and the comparable selective mouse solid tumors were used for in vivo testing.

RESULT

In vitro DMP 840 exhibited equal cytotoxicity for human tumors (including MX-1 directly cultured from nude mice), mouse tumors and normal cells. In vivo DMP 840 was only modestly active or inactive against the following mouse tumors: Mam 16/C, T/C = 30% (T/C = Percent Tumor Growth Inhibition); Mam 16/C/ADR, T/C = 33%; Colon 38, T/C = 9%; Panc 03, T/C = 53%; Colon 51/A, T/C = 28%; Panc 02, T/C = 52%; P388/0, 36% ILS (Percent Increased Life Span) and P388/ADR, 14% ILS. Furthermore, the antitumor activity was only observed at the highest non-toxic dose and was associated with a large body weight loss. In contrast, the agent was highly active against the human breast tumor MX-1 implanted subcutaneously in either athymic nude or SCID mice (Nudes: T/C = 0%; 1/5 cures; SCIDS: T/C = 0%; 5/5 cures).

CONCLUSIONS

Although there was no selective cytotoxicity in our clonogenic assay for human versus mouse tumor cell lines, selective activity in vivo for human xenograft tumors was noted. Overall, this compound is rather unique in its differential degree of in vivo activity for human versus mouse tumors.

IMPLICATIONS

Phase II trials, which are ongoing, will help determine if the preclinical in vivo selective activity of DMP 840 translates to clinical activity in man.

Comparative serum bactericidal activities of three doses of ciprofloxacin administered intravenously

The pharmacokinetics and serum bactericidal activities of three intravenous doses of ciprofloxacin were studied comparatively in 30 patients. Single 200-, 300-, and 400-mg intravenous doses of ciprofloxacin were given over 30 min to 10 patients each, and serum samples were obtained at 0.5, 1, 2, 3, 4, 8, and 12 h after the start of the infusion. Serum drug concentrations were determined by high-pressure liquid chromatography. Pharmacokinetic parameters were estimated by using noncompartmental analysis methods. Serum bactericidal activity against clinical isolates of Escherichia coli, Enterobacter cloacae, Pseudomonas aeruginosa, Acinetobacter calcoaceticus, and Staphylococcus aureus was determined for samples obtained at 0.5, 4, 8, and 12 h. Excellent activity was demonstrated up to 12 h by all doses against E. coli and E. cloacae. Much poorer titers were observed for the remaining organisms, although the 400-mg dose prompted improved results against P. aeruginosa with a mean bactericidal titer of 1:2.9 at 8 h. In conclusion, while the 200-mg dose appears to be largely adequate for infections caused by members of the family Enterobacteriaceae, it seems that when P. aeruginosa is involved, 400 mg twice a day or even three times a day is more appropriate. Intravenous ciprofloxacin performs poorly against A. calcoaceticus and S. aureus, even at a higher dose.

Evaluation of a portable prototype to analyze heart rate variability

Power spectrum analysis of heart rate fluctuations provide a quantitative noninvasive means of assessing the functioning of the cardiovascular control system. Until now the equipment used to study heart rate variability (HRV) have been complicated systems utilized mostly in research centers. Simpler systems are needed for routine clinical application. We have evaluated, through clinical practice, the usefulness of prototype equipment which allows acquisition and analysis of ECG signals by a portable electrocardiograph and a personal computer in which sophisticated software is installed. We performed one hundred forty-five recordings in twenty-two patients admitted to ICU. With this technique two different predictive patterns were detected: one concerning survivors, the other concerning nonsurvivors. Reliability, portability, simplicity and quality results are the main advantages of the system. The disadvantage is that it is difficult to perform HRV analysis in patients with ECG arrhythmia. This is because the program does not allow the choice of an arrhythmia-free section of the tachogram to analyze.

HIV infection and intravenous drug abuse: world perspective and epidemiology in Israel

As the second largest group of persons to have been infected with human immunodeficiency virus (HIV) and the main source of HIV transmission to heterosexual partners in the industrialized world, intravenous drug abusers (IVDAs) play an increasingly important role in the AIDS epidemic. The situation is particularly alarming in South and East Asia where a sharp increase in HIV seropositivity rate among IVDAs has occurred over just a few years. In Israel, the impact of HIV infection on IVDAs has remained limited with a prevalence of 2%-4.2%. In most cases, infection was contracted following travel and drug injection abroad. Israel continues to be a pre-epidemic area of HIV infection.

Heart rate variability and severe brain damage: preliminary data

Severe brain damage may cause alterations of cardiovascular function: heart rate, particularly, require the integrity of the vagal, sympathetic and central nervous systems. We studied brain-heart functional relation and neurovegetative modulation by spectral analysis of heart rate variability (HRV). This technique allows separate evaluation of the sympathetic and vagal components of heart rate modulation. In order to correlate changes in HRV with brain damage, we performed 45 recordings in 6 patients (5/1 M/F) by means of autoregressive analysis (AAR). All patients were admitted to the ICU for severe brain damage (anoxic, traumatic or vascular). In 4 patients clinical outcome was brain death, in 2 permanent vegetative status. Two different patterns were found: one in patients with brain death, the other in patients with vegetative status. The small number of patients does not allow definitive conclusions from collected data, but that application of spectral analysis of HRV seems to be a useful monitoring of brain damage subjects.

Preclinical studies for adoptive immunotherapy in bone marrow transplantation. Generation of anti-CD3 activated cytotoxic T cells from normal donors and autologous bone marrow transplant candidates

In order to obtain T cells for adoptive immunotherapy after autologous bone marrow transplantation (ABMT) for patients with resistant hematological malignancies, a culture system was developed for growing T cells and inducing non-MHC-restricted cytotoxicity using anti-CD3 monoclonal antibody (OKT3) activation. In this investigation, we show that (1) peripheral blood lymphocytes or bone marrow mononuclear cells (BMMNC) from normal donors and cancer patients can be activated with OKT3 and grown in interleukin-2; (2) normal BMMNC activated with OKT3/IL-2 exhibited non-MHC-restricted cytotoxicity and surface markers comparable to that exhibited by normal PBL activated with OKT3/IL-2; (3) both proliferation and cytotoxic functions were IL-2-dependent; (4) PBL activated with OKT3/IL-2 after cryogenic storage grew and killed comparable to PBL activated with OKT3/IL-2 prior to cryopreservation; (5) OKT3/IL-2-activated PBL and BMMNC obtained from 5 patients with non-Hodgkin's lymphomas (NHL) and 1 patient with acute myelogenous leukemia (AML) increased cell numbers 41-75-fold in 2 weeks of culture; 5 of 6 patients with NHL or AML had PBL and BMMNC that exhibited cytotoxic activity; and (6) contaminating leukemic cells did not overgrow in OKT3/IL-2-activated cultures and could no longer be detected on cytospin specimens after 3 weeks of culture. These data show that T cells in PBL or BMMNC from ABMT candidates can be activated with OKT3/IL-2 for adoptive immunotherapy in combination with ABMT.

Propagation of Waldenström's macroglobulinemia cells in vitro and in severe combined immune deficient mice: utility as a preclinical drug screening model

Waldenström's macroglobulinemia (WM) represents an indolent incurable human B-cell tumor. We have successfully established a permanent cell line, WSU-WM, without growth factors or viral transformation, from the pleural effusion of a 60-year-old man with IgM kappa WM. Phenotypic characterization of WSU-WM shows IgM lambda and expression of other B-cell markers. Karyotypic analysis shows a male chromosome complement with several clonal aberrations, including t(8;14)(q24;q32). Molecular characterization shows deletion of kappa and rearrangement of lambda light chain genes indicating a class switching. Both the secretory (s mu) and membrane (m mu) components of IgM are expressed. In addition, the breakpoint on 8q24 is downstream of exon 3 of the c-myc oncogene. WSU-WM grows in liquid culture and soft agar. When cells were injected subcutaneously in immune deficient mice, six of seven SCID mice developed subcutaneous tumors as opposed to three of seven in the athymic nude mice. When a WSU-WM SCID tumor was passaged in vivo in the SCID mice, the take rate was 100%. This xenograft model and a soft agar disk-diffusion assay were used to test the efficacy of standard chemotherapy agents against this tumor in vivo and in vitro, respectively. The cell line and the assays described herein can be used as a model to facilitate the discovery of new therapeutic agents or modalities for this disease.

Etiology of acute pelvic inflammatory disease proven by laparoscopy

BACKGROUND

Only a few studies have investigated the etiology of acute pelvic inflammatory disease (PID) in laparoscopy-proven cases using pelvic samples for culture. Most of these studies were conducted in North America and Scandinavia.

GOAL OF THE STUDY

To study the microbial etiology of laparoscopy-proven acute pelvic inflammatory disease in Israeli women.

STUDY DESIGN

A prospective survey of women admitted to a hospital for treatment of acute pelvic inflammatory disease. All diagnoses were laparoscopy confirmed. Specimens for culture were obtained from the pelvic cavity via the laparoscope, and two serum samples were sent for serologic studies.

RESULTS

Forty patients were studied. Their mean age was 34.4 years of age, and 27.5% had a history of PID. Chlamydia trachomatis infection was diagnosed in 14 (35%) patients (group A). Facultative and/or anaerobic bacteria were isolated from pelvic specimens of 7 (17.5%) patients (group B), one of these patients also had positive chlamydial serology. Mycoplasma hominis was cultured from a pelvic specimen of one woman, and herpes simplex virus grew from a pelvic sample of another patient in whom C. trachomatis was also found. In 19 (47.5%) women, the microbial etiology could not be determined (group C). In no case was Neisseria gonorrhoeae isolated. Stage I (mild) PID was diagnosed most often in group A (75% vs. 14% in group B [P < 0.02]), whereas the opposite was true for stage III (severe) PID (71.4% in group B vs 25% in group A [P = 0.07]). Tubal abscess was mainly diagnosed in group B patients (57% vs 16.6% in group A [P = 0.09]).

CONCLUSION

In Israel, C. trachomatis is the most common cause of PID, while gonococci are rarely involved in this infection.

Seroepidemiology of hepatitis B and D virus infection among intravenous drug addicts in Israel

To evaluate the prevalence of hepatitis B virus (HBV) and hepatitis D virus (HDV) infection among intravenous drug addicts (IVDA) in Israel, serum samples were collected from 400 asymptomatic individuals attending a methadone clinic in Tel Aviv. Overall 5.5% were HBsAg positive, 2.4% HBeAg positive, 52% anti-HBc positive and 6.6% were positive for anti-HD. Anti-HD was identified in 18% of addicts who were HBsAg positive and in 3% who were HBsAg negative and anti-HBc positive. Strong correlation was found between positivity to HBV antibodies and age and duration of drug use. History of jaundice correlated more strongly with anti-HD positivity than with presence of antibodies to HBV. We conclude that Israeli IVDA are less exposed to HBV and HDV infection than their North American and European counterparts.

Penetration of fleroxacin into breast milk and pharmacokinetics in lactating women

Fleroxacin was administered to seven lactating women as a single oral dose of 400 mg. Plasma, urine, and milk samples were collected for up to 48 h after administration. Drug concentrations were determined by a reversed-phase high-pressure liquid chromatography method and were used for the pharmacokinetic evaluation. At approximately 2 h after oral administration, a maximum concentration of 5.6 mg/liter was determined in plasma; the area under the plasma concentration-time curve (AUC) amounted to 70.3 mg.h/liter, and the elimination half-life in the postdistributive phase was 8 h. Total systemic clearance was 97.3 ml/min, and urinary excretion was 38% of the dose within 48 h. In addition, 8.6% of the N-demethyl metabolite and 4.4% of the N-oxide metabolite were recovered from urine. In comparison with previous results obtained with healthy male volunteers, the time to reach maximum concentrations in plasma was twice as long in the nursing women, and total clearance as well as urinary elimination were reduced by 25%. In breast milk, the mean maximum concentration was 3.5 mg/liter, which was reached 2.6 h after drug administration. The elimination half-life of fleroxacin in milk was identical to that in plasma, and the AUC reached 43.3 mg.h/liter. On the basis of the comparison of the AUC in milk versus the AUC in plasma, the proportion of fleroxacin penetration into milk was 62%. The cumulative excretion in milk amounted to only 0.219 mg within 48 h. On the basis of an average daily intake of milk of a breast-fed child of 150 ml/kg of body weight, the maximum daily ingested fleroxacin dose would not exceed 10 mg. However, quinolones are known to induce arthropathy in juvenile animals, and therefore, administration of fleroxacin to breast-feeding women cannot be allowed.

The penetration of ciprofloxacin into bronchial mucosa, lung parenchyma, and pleural tissue after intravenous administration

We have studied the concentrations of ciprofloxacin in serum, bronchial mucosa, lung parenchyma, and pleural tissue after a single intravenous dose of 200 mg in 20 patients subjected to lung surgery. The concentrations of ciprofloxacin in the tissues exceeded that in the serum by 3-fold to 7-fold: serum 0.6 micrograms.ml-1, bronchial mucosa 1.9 micrograms.g-1, lung parenchyma 3.4 micrograms.g-, and pleural tissue 1.7 micrograms.g-1. The achievable concentrations of ciprofloxacin in the tissues of the lower respiratory tract are above the MICs for most lung pathogens.

Bryostatin 1-induced hairy cell features on chronic lymphocytic leukemia cells in vitro

The phorbol esters induce differentiation of chronic lymphocytic leukemia (CLL) cells. Clinical use of this observation has been hampered by the fact that phorbol esters are also tumor promoters. In this study we demonstrate that another protein kinase C activator, without tumor promoting activity, has similar effects on CLL cells. Fresh leukemic cells from the peripheral blood of 13 patients with CLL were isolated and cultured in the absence (control) or presence of Bryostatin 1 or 12-0-tetradecanoylphorbol 13-acetate (TPA). Aliquots of cells were then analyzed after 24, 72 and 120 hours for morphological changes, acid phosphatase (ACP) and the co-expression of two hairy cell-associated surface antigens, CD22 and CD11c, by flow cytometry. Bryostatin 1 induced changes in shape and morphology similar to TPA, with adherence and increase in cell size, abundant cytoplasm and irregular cytoplasmic membrane. Both agents induced a statistically significant increase in the expression of CD22 and CD11c compared with control (p < 0.0008). There was no significant difference between the two agents in the degree of expression of these two markers. Both agents also induced ACP that was tartrate resistant (TRAP). These changes indicate that Bryostatin is as effective as TPA in inducing further differentiation of CLL cells to a hairy cell stage.

Carriage of methicillin-resistant Staphylococcus aureus by non-hospitalized subjects in Israel

The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in the anterior nares and axilla was studied in 920 non-hospitalized subjects: 350 drug addicts, 350 individuals presenting at a hospital emergency room for various reasons, and 220 hospital health care workers. S. aureus was isolated from 105 (11.4%) subjects, in six (6.3%) of whom the isolates were methicillin-resistant. The isolation rate of the organism and the prevalence of resistant strains in the different subgroups were, respectively: drug-addicts, n = 32 (9.1%), n = 2 (6.9%); emergency room patients, n = 36 (10.2%), n = 1 (3.2%); and hospital health care workers, n = 37 (16.8%), n = 3 (8.5%). Our findings suggest that MRSA remains uncommon in the community, while the prevalence of S. aureus carriage (including methicillin-resistant strains) in hospital personnel is quite similar in divergent geographical areas.

HTLV among Israeli intravenous drug abusers

Since human T lymphotropic virus (HTLV) infection was recently described in Israel and other Middle Eastern countries, we have investigated the presence of HTLV type 1 and type 2 in a group of 299 intravenous (IV) drug abusers who were seen at a large methadone clinic in the Tel Aviv area in 1986-1987. We found that 1.3% were seropositive to HTLV. Further testing revealed that HTLV1 was the only HTLV serotype. In addition, no coinfection HIV1/HTLV1 and no HIV2 infection were detected. Since all HTLV seropositives were born in Middle Eastern countries, did not travel outside Israel and were not infected by HIV1 or by HTLV type 2, it is possible that the source of HTLV1 infection in that group was in an endemic reservoir of HTLV1 in Israel. The detection of HTLV1 among IV drug abusers and among other groups in Israel necessitates more extensive HTLV testing in at-risk populations.

Human immunodeficiency virus infection among intravenous drug addicts in Israel--stable low prevalence over 34 months

A serological survey of 300 Israeli intravenous drug addicts in 1988-1989, showed a 2.3% prevalence of antibodies to human immunodeficiency virus (HIV), very similar to the finding of a previous study (2%) performed in the same population in 1986. Travel and drug injection abroad continue to be the most significant predictors of HIV seropositivity in this group. The relatively uncommon use of cocaine and the absence of 'shooting galleries' in Israel, appears to explain best the stable low prevalence of HIV infection among parenteral drug addicts in this country.

Distribution of ciprofloxacin in ascitic fluid following administration of a single oral dose of 750 milligrams

The penetration of ciprofloxacin into the ascitic fluid of eight patients was studied. Serum and ascitic fluid samples were obtained before and at 1, 2, 3, 6, and 12 h following administration of a single oral dose of 750 mg. Peak levels (mean +/- standard deviation) were 4.0 +/- 0.7 micrograms/ml in serum and 2.6 +/- 0.6 micrograms/ml in ascitic fluid; the areas under the curve (0 to 12 h) were 29.1 +/- 6.5 micrograms.h/ml in serum and 20.7 +/- 5.0 micrograms.h/ml in ascitic fluid. The concentrations that were achieved are well above the MICs of ciprofloxacin for the members of the family Enterobacteriaceae that cause spontaneous bacterial peritonitis.

Penetration of ciprofloxacin into human peritoneal tissue following a single oral dose of 750 milligrams

The penetration of ciprofloxacin into the peritoneal tissue was studied in 10 patients after a single oral dose of 750 mg given 5.6 hours (mean) before elective laparotomy. The mean tissue level was 0.29 micrograms/ml (range, 0.082 to 0.96 micrograms/ml) while the mean concomitant serum level was 1.3 micrograms/g (range, 0.52 to 2.57 micrograms/g). The achieved concentrations are above the minimum inhibitory concentrations (MICs) of ciprofloxacin for most gram-negative bacteria commonly involved in intra-abdominal infections.

Peritonitis caused by Pseudomonas putrefaciens in patients undergoing continuous ambulatory peritoneal dialysis

Three cases of peritonitis caused by Pseudomonas putrefaciens in patients undergoing continuous ambulatory peritoneal dialysis are described. In two cases asymptomatic colonization of the dialysate preceded overt infection. All patients responded successfully to standard antibiotic therapy with gentamicin or ofloxacin. This is the first report of peritonitis caused by P. putrefaciens.

The differential leukocyte count in adults with acute gastroenteritis

The total and differential leukocyte count of 4 groups of patients, admitted to the hospital because of acute gastroenteritis was evaluated. The 4 groups included: (a) 131 adult patients with positive stool culture for shigella; (b) 23 children (age less than 15 years) with positive stool culture for shigella; (c) 52 adult patients with positive stool culture for salmonella; (d) 43 adult patients with negative stool culture for bacterial pathogens. The total leukocyte count did not contribute to the differential diagnosis between shigella gastroenteritis and gastroenteritis of other etiology. However, the absolute band count was significantly higher in adults with shigella gastroenteritis. Moreover, a band to total neutrophil ratio further increased the diagnosis specificity. The differential leukocyte count can contribute to early diagnosis of shigellosis in adult patients.

Cytoplasmic crystalloids in the periodontal tissue of beige mice

The periodontal tissue of beige mice has been examined by electron microscopy. Specimens of the periodontal tissue from the right mandibular first molars of 10 male beige (bg/bg) and 5 male non-beige (bg/+, controls) mice, were fixed in a mixture of glutaraldehyde and paraformaldehyde, and then decalcified in EDTA. After fixation in osmium tetroxide, the specimens were dehydrated and embedded in epon resin. Ultrathin sections were then stained with uranyl acetate and lead citrate, and observed by electron microscopy. A larger number of cytoplasmic crystalloids were seen in the lysosomes of the histiocytes of the beige mice than in the non-beige mice. These cytoplasmic crystalloids showed striation structures composed of linear densities that were oriented longitudinally, transversely, and obliquely, with about a 4-nm periodicity. The periodontal tissue of the beige mice contained several cells with numerous cytoplasmic crystalloids, whereas there were few cells with fewer crystalloids in the non-beige mice.

Value and limitations of transesophageal echocardiographic monitoring during percutaneous balloon mitral valvotomy

To determine the utility of transesophageal echocardiographic monitoring during percutaneous balloon mitral valvotomy, we analyzed data from 40 consecutive patients who had been randomly assigned to undergo balloon mitral valvotomy under transesophageal echocardiographic guidance or without echo. All procedures were carried out under general anaesthesia. The completion rate (100% vs 73%), the procedure time (108 +/- 28 min vs 65 +/- 18 min), the X-ray exposure time (62 +/- 13 vs 33 +/- 12 min), resulted significantly (P less than 0.001) more favorable in the echo-monitored patients. Moreover, a lower rate of major complications (cardiac tamponade, large residual atrial shunting, and severe mitral regurgitation) was noted in the echo-monitored patients. The achieved final area of the mitral valve did not differ significantly between the two groups. From an evaluation of results as a whole, 96% of the echo-monitored procedures were successful, whereas only 40% of the procedures conducted without echocardiographic control achieved a satisfactory final result in absence of major complications. We conclude that transesophageal echocardiography is a safe, effective, and valuable tool to monitor each step of balloon mitral valvotomy in order to shorten the time of the procedure, and to improve the results of this complex interventional catheterization technique.

Isolation of Chlamydia trachomatis from prostatic tissue of patients undergoing transurethral prostatectomy

Chlamydia trachomatis was isolated from three of 100 prostatic tissue specimens obtained from patients undergoing transurethral resection of the prostate. All examined patients were free from symptoms of urethral or prostatic inflammation. Our findings are in accordance with the high incidence of asymptomatic chlamydial infection of the lower genital tract and the increasing evidence that C. trachomatis can cause infection of the prostate.

Prevalence of sexually transmitted pathogens among women attending a methadone clinic in Israel

OBJECTIVE

To assess the prevalence of sexually transmitted pathogens in drug-addicted women in Tel Aviv, Israel.

DESIGN

A prospective study conducted between March and July 1987.

SETTING

A methadone clinic in Tel Aviv, Israel.

SUBJECTS

Sixty four asymptomatic female drug addicts were studied; 38 of them were declared practising prostitutes.

METHODS

Cervical specimens were obtained for cultures, and blood samples were drawn for serological tests. Demographic data and sexual histories were obtained using a standard questionnaire.

RESULTS

Chlamydia trachomatis was detected in the cervix of 25% of women; 98% had antibody titres (greater than 1:64). Mycoplasma hominis and Ureaplasma urealyticum were isolated in 57% and 65% respectively. Gardnerella vaginalis was detected in 17% of women, and herpes simplex virus was cultured from two prostitutes. Five per cent of women were carriers of HBsAg, while 57% had HBSs and/or HBc antibodies. Only one prostitute had specific treponemal antibodies. In no case were gonococci or group B streptococci isolated, and HIV serology was invariably negative.

CONCLUSION

Chlamydia and genital mycoplasmas appear to be the prevailing pathogens in Israeli drug-addicted women, while gonococci and Treponema pallidum occur only rarely.

Penetration of ofloxacin into human lung tissue following a single oral dose of 200 milligrams

The penetration of ofloxacin into lung tissue was studied in 10 patients subjected to pulmonary surgery. Samples of blood and lung tissue were obtained 3 to 8 h (mean, 5 h) after oral administration of 200 mg. The mean level in tissue was 2.17 +/- 0.5 micrograms/g, while the mean level in serum was 0.85 +/- 0.23 micrograms/ml. The mean lung tissue/serum concentration ratio was 2.55 +/- 0.30. The achievable levels of ofloxacin in lung tissue are above the MICs for most pulmonary pathogens.

Successful emergency percutaneous balloon mitral valvotomy in a patient with massive left atrial thrombosis: utility of transesophageal echocardiographic monitoring

Emergency percutaneous balloon mitral valvotomy was carried out successfully in a 65-year-old woman with severe mitral stenosis and massive left atrial thrombosis. Transesophageal echocardiography was of great value in monitoring each step of the procedure in order to avoid systemic embolization due to improper manipulation of the dilating apparatus within the left atrium.

Mitral valve disruption following percutaneous balloon valvuloplasty

Two cases of massive mitral regurgitation due to mitral valve disruption following percutaneous balloon valvuloplasty are reported. This severe complication occurred in two elderly women with recurrent mitral stenosis after previous surgical commissurotomy. Due to their unstable hemodynamic and clinical condition, both patients underwent emergency valve replacement. At surgery, the commissures appeared fused and heavily calcified; the chordae tendineae thickened, shortened, and fused; and the leaflets presented a large tear with sheared edges. Because the technical aspects of both procedures were unremarkable, the anatomic features of the mitral valve seemed to affect the occurrence of severe mitral regurgitation. Percutaneous balloon valvuloplasty should be therefore applied carefully to patients with prior surgical valvotomy, in whom the structural alterations of the mitral apparatus may predispose to severe valvular damage.

Value of transesophageal echocardiography during repair of congenital heart defects

Two-dimensional transesophageal color Doppler echocardiography was employed intraoperatively in 30 children undergoing repair of a variety of simple and complex cardiac malformations. There were 16 female and 14 male patients, with a mean age of 9 +/- 3 years (range, 4 to 13 years) and a mean weight of 31 +/- 9 kg (range, 16 to 50 kg), 16 children weighing less than 30 kg. A standard, commercially available transesophageal echocardiography probe (5 MHz, 64 elements) was used in all patients without complications. Transesophageal echocardiography proved helpful in selecting the surgical approach, in assessing the adequacy of surgical repair, in detecting residual intracardiac shunts, and in allowing uninterrupted monitoring of ventricular performance throughout the procedure. Our initial experience suggests that transesophageal echocardiography is a valuable tool to be used in children with congenital cardiac malformations, particularly in those requiring complex intracardiac procedures. The amount of information obtained by the surgeon should favor the routine use of transesophageal echocardiography during open heart procedures and stimulate the development of probes to be safely used even in infants and newborns.

Prevalence of cryptosporidiosis in Israeli children with diarrhoea

In a prospective study, Cryptosporidium oocysts were detected in seven (3.25%) immunocompetent children with diarrhoea. The predominant clinical features were watery diarrhoea and vomiting. The patients' mean age was 19 years and infection was more common in late summer-autumn than in the rest of the year. This first survey on cryptosporidiosis in Israeli children has shown a prevalence similar to that observed in other developed countries.

Varied presentations of sporadic group A streptococcal bacteremia: clinical experience and attempt at classification

The epidemiologic, clinical, and laboratory aspects of group A streptococcal bacteremia were studied in 33 patients seen at two urban hospitals in the Tel Aviv (Israel) area, over an 8-year period. Most patients (two-thirds) were female. Clinically significant bacteremia was observed in 26 patients, two of whom acquired their infection (puerperal sepsis) during hospitalization. A portal of entry, mainly cutaneous, was recognized in 61% of the patients, and a chronic underlying condition was observed in 69%. The case-fatality rate was 27%, with death occurring predominantly in patients admitted with shock or cryptogenic bacteremia. Our clinical experience and literature review show that the presentation of group A streptococcal bacteremia is diverse, with transient bacteremia of uncertain clinical significance on one end of the spectrum and overwhelming sepsis on the other. A practical classification of the various clinical forms of group A streptococcal bacteremia is proposed.

Oral ciprofloxacin treatment of Pseudomonas aeruginosa osteomyelitis

Twenty-two adult patients with osteomyelitis due to Pseudomonas aeruginosa were enrolled in an open, prospective cooperative study to determine the efficacy of oral ciprofloxacin therapy in a dosage of 750 mg twice a day. Twenty patients received a complete course of treatment and could be assessed for efficacy. There were 12 men and 8 women, with a mean age of 55 years. Six patients had undergone previous, unsuccessful attempts at therapy. Eight patients had clinically important underlying conditions. The most common sites of infection were the sternum (six patients), hip (four patients), vertebrae (four patients), and tibia (two patients). Initial surgical debridement was performed in 18 of the 20 assessable patients. The mean duration of treatment was 2.85 months (range, 1 to 4 months), and that of the follow-up was 27 months (range, 6 to 52 months). Cure was achieved in 19 of the 20 (95%) patients. The only significant adverse effect (which prompted discontinuation of therapy) was severe nausea in one case. Oral ciprofloxacin coupled with adequate debridement is an effective, convenient, and safe therapy in patients with acute and subacute P. aeruginosa osteomyelitis.

Left atrial myxoma: excision guided by transesophageal cross-sectional echocardiography

We present a patient with a left atrial myxoma in whom the intraoperative use of transesophageal cross-sectional echocardiography proved helpful in selecting the most appropriate surgical approach, thus allowing expeditious and complete excision of the tumor. This technique, which permits continuous monitoring of cardiac function throughout open heart procedures, appears particularly valuable in patients with intracardiac masses.

Cross resistance to ciprofloxacin and other antimicrobial agents among clinical isolates of Acinetobacter calcoaceticus biovar anitratus

Using an agar dilution assay, for 66 of 104 (63.5%) clinical isolates of Acinetobacter calcoaceticus biovar anitratus, the MIC of ciprofloxacin was greater than or equal to 1.0 micrograms/ml. Cross resistance was demonstrable to ciprofloxacin and gentamicin (P less than 0.001), amikacin (P less than 0.01), cefotaxime (P less than 0.001), azlocillin (P less than 0.001), ceftazidime (P less than 0.001), trimethoprim-sulfamethoxazole (P less than 0.001), and minocycline (P less than 0.05). The mean MIC of ciprofloxacin for drug-susceptible isolates was consistently lower than that for resistant isolates; however, these differences were significant only for amikacin (P = 0.036).

Penetration of aminoglycosides into human peritoneal tissue

Each of 30 patients underwent elective laparotomy following administration of a single intravenous dose of amikacin, netilmicin or tobramycin. Therapeutic concentrations of amikacin were achieved in peritoneal tissue in 10/10 patients. Only 13/20 samples from patients receiving the other two antibiotics showed antibacterial activity. Our data suggest that the penetrability of tobramycin (53%) and amikacin (39%) into the uninflamed peritoneal tissue is superior to that of netilmicin (16%).

Shigellosis in adults: epidemiologic, clinical, and laboratory features

One hundred and sixteen cases of adult patients hospitalized for shigellosis have been reviewed. The most common presentation included diarrhea (most frequently watery), fever, and abdominal pain, while dysentery has been less frequent. S. flexneri infection, as compared to S. sonnei, was more common in elderly patients and in males, and was characterized by a more prolonged clinical course. Abnormalities of serum electrolytes and hepatic enzymes were the most common laboratory complications, most often seen in elderly patients. Most isolates exhibited susceptibility to the common antimicrobial agents used in shigellosis therapy.

Prevalence of antibodies to human immunodeficiency virus among intravenous drug users in Israel--association with travel abroad

A serological survey of 400 Israeli intravenous drug users showed a 2% prevalence of antibodies to human immunodeficiency virus (HIV). No difference was found between seropositive and seronegative subjects regarding mean age, duration of intravenous drug use, and needle sharing. Seropositivity was, however, significantly associated with travel abroad since 1980 (P less than 0.001), and with intravenous drug injection abroad (P = 0.04). These data indicate that Israel is a pre-endemic area for HIV infection, and transmission of the virus among Israeli intravenous drug users seems to be infrequent at the current level of exposure.