Ritonavir-saquinavir dual protease inhibitor compared to ritonavir alone in human immunodeficiency virus-infected patients

The objective of this study was to evaluate the antiretroviral efficacy and safety of ritonavir (600 mg twice a day [b.i.d.])-saquinavir (400 mg b.i.d.) compared to ritonavir (600 mg b.i.d.) in patients pretreated and receiving continued treatment with two nucleoside analogs. The study was placebo controlled, randomized, and double blind. Inclusion criteria included protease inhibitor naive status and a viral load of >10,000 copies/ml. The main end point was viral load at week 24. Forty-seven patients were included (25 given ritonavir and 22 given ritonavir-saquinavir) and monitored until week 48. At inclusion, 23% had had at least one AIDS-defining event. Previous treatment durations (mean and standard deviation) were 42 +/- 25 and 37 +/- 23 months, viral loads were 4.75 +/- 0.62 and 4.76 +/- 0.50 log(10) copies/ml, and CD4 cell counts were 236 +/- 126 and 234 +/- 125/mm(3) in the ritonavir and ritonavir-saquinavir groups, respectively. At week 24, viral loads were 2.81 +/- 1.48 and 2.08 +/- 1.14 log(10) copies/ml (P = 0.04) and CD4 cell counts were 330 +/- 151 and 364 +/- 185/mm(3) (P = 0.49) in the ritonavir and ritonavir-saquinavir groups, respectively. Similar results were observed at week 48. Moreover, at week 48, 40 and 68% (P = 0.05) and 28 and 59% (P = 0.03) of patients achieved viral suppression at below 200 and 50 copies/ml in the ritonavir and ritonavir-saquinavir groups, respectively. At week 24, six patients in the ritonavir group but only one in the ritonavir-saquinavir group had key mutations conferring resistance to protease inhibitors. Clinical and biological tolerances were similar in both groups. In nucleoside analog-pretreated patients, ritonavir-saquinavir has higher antiretroviral efficacy than and is as well tolerated as ritonavir alone.

Evidence for the involvement of nitric oxide in the control of steroid secretion by the frog adrenal gland

Nitric oxide (NO) has been found to modulate the response of rat, bovine and human adrenocortical cells to corticotropic factors. The aim of the present study was to investigate the possible involvement of NO in the control of corticosteroid secretion in the frog Rana ridibunda. Histochemical studies using the NADPH-diaphorase reaction and immunohistochemical labeling with antibodies against NO synthase (NOS) revealed that NOS is exclusively expressed in chromaffin cells. The NO donor sodium nitroprusside (SNP) and the NO synthase inhibitor Nw-nitro-L-arginine (L-NO(2)Arg) did not modify the spontaneous production of corticosterone and aldosterone by perifused adrenal slices. Similarly, L-NO(2)Arg had no effect on the secretory responses induced by ACTH, angiotensin II (AII) and endothelin-1 (ET-1). In contrast, SNP significantly inhibited the stimulatory effects of ACTH, AII and ET-1 on corticosterone and aldosterone secretion. These data provide the first evidence for a modulatory role of NO on adrenocortical cell activity in amphibians.

[Renal failure during treatment with Ambisome]

BACKGROUND

Although renal function is generally unaffected by liposome formulations of amphotericin B-deoxycholate, there is nevertheless a risk.

CASE REPORTS

Two patients immunodepressed patients treated for candidosis involving the mouth and esophagus unresponsive to local care and flucanazol developed renal failure when given the liposome formulation of amphotericin B-deoxycholate (AmBisome). In one with normal renal function prior to treatment, moderate impairment was observed after initiating AmBisome. In the second patient, impaired renal function worsened after initiating treatment with amphotericin B-deoxycholate then progressed to very severe renal failure after switching to AmBisome.

CONCLUSION

The indication for AmBisome (amphotericin B-deoxycholate treatment in patients with active renal impairment) must not overshadow the risk of worsening renal function under treatment.

The effect of the endozepine triakontatetraneuropeptide on corticosteroid secretion by the frog adrenal gland is mediated by activation of adenylyl cyclase and calcium influx through T-type calcium channels

We have recently found that, in the frog adrenal gland, endozepines are present in chromaffin cells and we have shown that the triakontatetraneuropeptide TTN is a potent stimulator of corticosteroid secretion in vitro. In the present study, we have investigated the transduction mechanisms mediating the corticotropic effect of TTN on adrenocortical cells. Incubation of adrenal explants with graded concentrations of TTN induced a dose-dependent increase in cAMP formation, but did not affect polyphosphoinositide metabolism. Pretreatment of adrenal cells with the protein kinase A inhibitor H-89 markedly reduced the stimulatory effect of TTN on corticosterone and aldosterone secretion by perifused cells, whereas the phospholipase C inhibitor U-73122 did not affect the TTN-evoked stimulation of corticosteroid output. Incubation of adrenal cells with cholera toxin abolished the stimulatory effect of TTN on steroid secretion. Administration of a brief pulse of TTN (10(-6) M) in the vicinity of cultured adrenocortical cells induced a robust increase in the concentration of intracellular calcium ([Ca2+]i). Repeated pulses of TTN resulted in a gradual attenuation of the responses, indicating the existence of a desensitization phenomenon. Incubation of the cells with the T-type calcium channel blocker mibefradil significantly reduced the TTN-evoked [Ca2+]i increase, whereas the L-type calcium channel blocker nifedipine and the N-type calcium channel blocker omega-conotoxin GVIA had no effect. Incubation of adrenal cells with H-89 markedly reduced the stimulatory effect of TTN on [Ca2+]i. The involvement of calcium in steroid secretion induced by TTN has also been investigated. Administration of mibefradil significantly reduced the TTN-evoked stimulation of steroid production, whereas nifedipine was devoid of effect. Taken together, these data indicate that in frog adrenocortical cells, the endozepine TTN stimulates cAMP formation and calcium entry through T-type calcium channels. The effects of TTN on the adenylyl cyclase/protein kinase A pathway and calcium influx both contribute to the stimulatory action of the peptide on corticosteroid secretion.

Safety and efficacy of ritonavir and saquinavir in combination with zidovudine and lamivudine

BACKGROUND

Ritonavir is a potent inhibitor of cytochrome P4503A4 that strongly increases saquinavir bioavailability. In this study we assessed the safety and antiretroviral efficacy of the combination of these two compounds in patients pretreated and receiving continued treatment with zidovudine and lamivudine who were protease inhibitor naive and who had a CD4 cell counts below 200/mm3.

METHODS

In this 48-week pilot study, all patients received 600 mg ritonavir and 400 mg saquinavir twice daily. Administration of zidovudine and lamivudine was continued without a change in previous doses. Viral load, CD4 cell count, and the emergence of resistance to the two protease inhibitors were evaluated repeatedly up to week 48.

RESULTS

Sixteen patients were included in the study. Previous nucleoside analog treatment duration was 48+/-22 months (mean +/- SD). Two patients quit taking both protease inhibitors within 2 weeks. The ritonavir dose had to be reduced in 10 other patients because of side effects. Between inclusion and week 48, plasma viremia varied from 4.87+/-0.43 to 3.00+/-1.29 log10 copies/mL and CD4 cell counts ranged from 98+/-61 to 250+/-139/mm3. Ten patients (63%) had viral loads below 200 copies/mL and 7 (44%) had viral loads below 50 copies/mL. A single key mutation that conferred ritonavir resistance I84V and V82A/V developed in two patients. A mutation at codon 54 developed in another patient. These mutations were associated with repeated cessations of antiretroviral treatment. No lipodystrophy was observed.

CONCLUSION

Ritonavir and saquinavir in combination are quite well tolerated and induce a high and sustained antiretroviral efficacy. A four-drug combination that includes these two protease inhibitors should be considered as a first line of treatment in patients with low CD4 cell counts.

Amplification of the six major human herpesviruses from cerebrospinal fluid by a single PCR

We used a novel type of primer system, a system that uses stair primers, in which the primer sequences are based on consensus sequences in the DNA polymerase gene of herpesvirus to detect herpesviruses by PCR. A single PCR in a single tube detected the six major herpesviruses that infect the central nervous system: herpes simplex virus type 1 (HSV-1), and type 2 (HSV-2), cytomegalovirus (CMV), Epstein-Barr virus (EBV), varicella-zoster virus (VZV), and human herpesvirus 6 (HHV-6). We used the technique to analyze 142 cerebrospinal fluid (CSF) samples that had been stored at -80 degrees C and compared the results with those obtained previously for the same samples by standard, targeted PCR. Four hundred one targeted PCR tests had been run with the 142 samples to detect HSV-1, HSV-2, CMV, and VZV; screening for EBV and HHV-6 was not prescribed when the samples were initially taken. Eighteen CSF samples tested positive by classic targeted PCR. The herpesvirus consensus PCR detected herpesviruses in 37 samples, including 3 samples with coinfections and 17 viral isolates which were not targeted. Two samples identified as infected by the targeted PCR tested negative by the consensus PCR, and eight samples that tested positive by the consensus PCR were negative by the targeted PCR. One hundred three samples scored negative by both the targeted and the consensus PCRs. This preliminary study demonstrates the value of testing for six different herpesviruses simultaneously by a sensitive and straightforward technique rather than screening only for those viruses that are causing infections as suggested by clinical signs.

The stimulatory effect of endothelin-1 on frog adrenocortical cells is mediated through both the phospholipase C and the adenylyl cyclase transduction pathways

We have previously shown that endothelin-1 (ET-1) stimulates corticosterone and aldosterone secretion by the frog adrenal gland through activation of ET(A) receptors. In the present study, we have investigated the transduction pathways involved in the corticotropic action of ET-1. Exposure of frog adrenal explants to ET-1 provoked a time- and dose-dependent increase in inositol phosphate production and a parallel decrease in membrane polyphosphoinositide content. Incubation of adrenal explants with ET-1 also induced a dose-related increase of cAMP formation. The selective ET(A) receptor antagonist BQ-485 totally abolished the stimulatory effects of ET-1 on both inositol phosphate and cAMP production. In contrast, the selective ET(B) receptor agonist IRL 1620 did not significantly modify polyphosphoinositide hydrolysis or cAMP formation. Administration of the phospholipase C inhibitor U-73122 or the protein kinase A inhibitor H-89 to perifused frog adrenal slices significantly reduced the stimulatory effect of ET-1 on corticosterone and aldosterone secretion. Concomitant administration of the two inhibitors almost completely suppressed the corticotropic effect of ET-1. Taken together, these data indicate that, in the frog adrenal gland, the stimulatory effect of ET-1 on corticosteroid secretion is mediated through activation of both the phospholipase C and the adenylyl cyclase transduction pathways.

Opportunistic infections occurring during highly active antiretroviral treatment

OBJECTIVE

To analyse the characteristics of opportunistic infections in patients receiving highly active antiretroviral treatment (HAART).

DESIGN AND METHODS

A retrospective study performed in seven hospitals, included all patients starting treatment by ritonavir or indinavir between 26 March and 31 December 1996. Patients were evaluated for the development of AIDS-defining events. Clinical evaluation, plasma HIV-1 RNA quantification, CD4 cell count were recorded at baseline and at the onset of the event.

RESULTS

Four hundred and eighty-six patients were included: 44.2% had a CD4 cell count below 50 x 10(6) cells/l. Fifty clinical events were recorded in 46 patients with a mean follow-up of 6.1 months, of which 34 events (68%) were observed during the first 2 months of HAART. Eighteen of these occurred despite a reduction of viral load by at least 1.5 log10) and a 100% increase of the CD4 cell count compared with that at the onset of the event, corresponding to 11 cytomegalovirus infections, five mycobacterial infections, one case of cryptococcosis, and one case of Varicella-Zoster virus-related acute retinal necrosis. Among the 16 events observed after the second month, six occurred despite a marked biological improvement, corresponding to a recurrence in five of six patients who had stopped their maintenance therapy. Events were one cytomegalovirus infection, two mycobacterial infections, one episode of oesophageal candidiasis and one cryptococcal meningitis.

CONCLUSION

In patients at high risk of developing an opportunistic infection prior to the institution of a HAART regimen, prophylaxis should not be discontinued during the first 2 months of treatment, and maintenance therapy should be carried on despite a significant increase in the CD4 cell count.

Mechanism of action of endothelins on adrenocortical cells

Endothelins (ETs) play a pivotal role in the control of various endocrine and neuroendocrine tissues. In this review, we discuss the involvement of ETs as possible regulators of steroid secretion and we describe the mechanism of action of ETs on adrenocortical cells. The occurrence of ETs has been demonstrated in the human, porcine and rat adrenal gland. In humans, immunohistochemical and biochemical techniques have reported that ETs are localized exclusively in the cortex but the presence of ETs has also been detected in pheochromocytomas. In vitro studies have shown that ETs stimulate aldosterone secretion by adrenal tissues in various mammalian and amphibian animal models. The receptor subtype involved in the corticotropic action of ETs clearly differs among the various vertebrate species studied. In rat, the effect of ETs is mediated through an ET(B) receptor subtype while, in frog, an ET(A) receptor is implicated in the stimulatory action of ETs. In human adrenocortical cells, both ET(A) and ET(B) receptor subtypes are involved in the corticotropic effect of ETs. Activation of adrenal receptors causes an elevation of inositol trisphosphates associated with an increase in cytosolic calcium concentration. In addition, ETs induce an elevation of prostaglandin E2 (PGE2) and prostacyclin PGI2 production in the adrenal tissue, indicating that prostanoids may act as second messengers of ETs. It thus appears that ETs present in the adrenal gland may act as paracrine factors to stimulate the secretory activity of adrenocortical cells.

The presence of cytoplasmic antineutrophil cytoplasmic antibodies (C-ANCA) in the course of subacute bacterial endocarditis with glomerular involvement, coincidence or association?

Antineutrophil cytoplasmic antibodies positivity with cytoplasmic pattern (C-ANCA) and proteinase-3 (PR-3) specificity was found in two patients with both subacute bacterial endocarditis (SBE) and glomerular involvement. Renal biopsy showed membranoproliferative glomerulonephritis in one case and focal segmental glomerulonephritis in the second case. Immunofluorescence study showed granular immune deposits in both cases evocating immune complex glomerulonephritis. Renal and biological manifestations disappeared with clinical improvement secondary to antibiotherapy. Physicians have to consider the possible occurrence of such C-PR-3 ANCA, claimed to be specific markers for Wegener's granulomatosis, in infectious diseases such as SBE. Hence we focus on the necessity of performing a renal biopsy with light microscopy and immunofluorescence studies in all patients with ANCA associated glomerular disease.

Longitudinal study of HIV-specific cytotoxic lymphocytes in HIV type 1-infected patients: relative balance between host immune response and the spread of HIV type 1 infection

To evaluate the contribution of a specific cytotoxic response in the control of HIV infection in relation to clinical status, we performed serial analysis of anti-Env and anti-Gag cytotoxic activity in 13 infected individuals over a 6- to 10-year period, using cryopreserved peripheral blood mononuclear cells (PBMCs). Autologous EBV-transformed B cell lines infected in vitro with recombinant vaccinia viruses expressing HIV-1 env and gag genes were used as targets. Without any stimulation of the effector cells, we were able to show an anti-HIV cytotoxic activity in the PBMCs of 12 of 13 HIV-1-infected patients, consistent with chronic immune activation in HIV infection. Different patterns of HIV-specific cytotoxic activity were observed, and the extent of this cytotoxic response varied between the clinically defined groups of individuals. No direct relationship was observed with the number of CD4 and CD8 lymphocytes during the observation period. However, patients who remained asymptomatic had a more vigorous cytotoxic response than patients with clinical deterioration during the observation period, and a significant difference was observed for HIV Gag-specific CTL activity. From these data, we suggest that the HIV-specific cytotoxic response has a protective role in the course of HIV infection.

Impact of protease inhibitors on AIDS-defining events and hospitalizations in 10 French AIDS reference centres. Fédération National des Centres de Lutte contre le SIDA

OBJECTIVE

To assess the clinical and economic consequences of the use of protease inhibitors in the treatment of HIV infection.

DESIGN

Multicentric, observational, retrospective cohort study.

SETTING

Ten AIDS reference centres in France.

PATIENTS

All patients followed in each centre from September 1995 through October 1996.

MAIN OUTCOME MEASURES

AIDS-defining events, death, health-care resources use, administration of antiretroviral therapy.

RESULTS

Data from 7749 patients in 10 centres showed a drop in hospitalization days by 35%, new AIDS cases by 35%, and deaths by 46%. In the same period, the proportion of patients receiving antiretrovirals rose from 36 to 53% including highly active antiretroviral therapy (HAART), which rose from 0.3 to 18%. Overall cost evaluation showed a slight increase of monthly treatment cost of US$ 12 per patient. Comparison of the three centres that used HAART earliest to the three centres that used it latest showed a clear benefit to early HAART with a drop in hospitalization days by 41%, new AIDS cases by 41% and deaths by 69%. The proportion of patients with HAART rose to 27% and monthly health-care cost decreased by US$ 248852 (i.e., by US$ 101 per patient per month). Late prescribing centres experienced a less marked effect with a drop in hospitalization days by 22%, new AIDS cases by 31%, and deaths by 32.5%. Proportion of patients with HAART rose to 12% and monthly health-care costs increased by US$ 113578 (i.e., by US$ 38 per patient per month).

CONCLUSIONS

This study supports the extensive use of HAART in HIV-infected patients.

Effect of endothelin-1 on corticosteroid secretion by the frog adrenal gland is mediated by an endothelinA receptor

We have previously reported that endothelin-1 (ET-1) stimulates the in vitro secretion of corticosterone and aldosterone from the adrenal gland of the frog Rana ridibunda. The aim of the present study was to investigate the pharmacological profile of the endothelin receptor subtype involved in the corticotropic effect of ET-1. The mixed ET(A)/ET(B) receptor antagonist Ro 47-0203 (10(-5) M) totally blocked the stimulatory effect of ET-1 (5 x 10(-9) M) on corticosterone and aldosterone secretion. The action of ET-1 was also inhibited by the selective ET(A) receptor antagonist BQ-485 (10(-7) M). In contrast, the selective ET(B) receptor antagonist IRL 1038 (10(-6) M) did not affect the response of the frog adrenal gland to ET-1. In addition, the selective ET(B) receptor agonist IRL 1620 (10(-6) M) did not mimic the stimulatory effect of ET-1. The high affinity ET(C) receptor agonist endothelin-3 (ET-3) stimulated corticosteroid secretion, but was 400 times less potent than ET-1. Moreover, the action of ET-3 was also blocked by BQ-485 (10(-7) M). These data indicate that the stimulatory effects of ET-1 and ET-3 on corticosteroid secretion by the frog adrenal gland are mediated by an ET(A) receptor subtype.

Comparative activities of new fluoroquinolones, alone or in combination with amoxicillin, trimethoprim-sulfamethoxazole, or rifampin, against intracellular Listeria monocytogenes

We studied the activities of the new fluoroquinolones clinafloxacin, levofloxacin, ofloxacin, and sparfloxacin alone or in combination on the intracellular growth of Listeria monocytogenes. Against intracellular growth of the four strains tested, a similar reduction of the bacterial count was obtained with clinafloxacin at the dose of 10 x MIC (delta log10 CFU/ml = -2.19 +/- 0.24), with levofloxacin at 8 x MIC (delta log10 CFU/ml = -2.28 +/- 0.25), and with sparfloxacin at 4 x MIC (delta log10 CFU/ml = -2.16 +/- 0.21) after 24 h of incubation. The combination of the quinolones with trimethoprim-sulfamethoxazole or amoxicillin did not show a substantial increase in activity compared to the fluoroquinolone alone. Antagonism with rifampin was strongly suggested. No modification of the MIC was observed after 20 successive infections of HeLa cells and contact with subinhibitory concentrations of clinafloxacin, levofloxacin, and sparfloxacin for 24 h. We conclude that clinafloxacin, levofloxacin, or sparfloxacin could represent a therapeutic alternative to amoxicillin for the treatment of Listeria infections in adults, especially clinafloxacin, whose MIC is low (0.06 to 0.12 micrograms/ml), and whose best activity against intracellular L. monocytogenes was obtained at a concentration of 1.2 micrograms/ml, which is similar to clinically achievable levels. The results must be confirmed in an experimental model.

Localization, identification, and action of galanin in the frog adrenal gland

The distribution of galanin-like immunoreactivity was studied in the adrenal gland of the frog Rana ridibunda using the indirect immunofluorescence technique. A dense network of varicose fibers immunoreactive to galanin was found in the adrenal tissue. A combination of HPLC analysis and RIA detection was used to characterize galanin-like immunoreactivity in frog adrenal gland extracts. The elution profile revealed the existence of a single form of galanin exhibiting the same retention time as synthetic frog galanin. The possible involvement of galanin in the regulation of corticosteroid secretion was investigated in vitro using a perifusion system for frog adrenal slices. For concentrations ranging from 10(-9) to 3 x 10(-6) M, synthetic frog galanin induced a dose-dependent inhibition of corticosterone and aldosterone release. Repeated pulses of galanin (10(-6) M), given at 90-min intervals, resulted in a reproducible inhibition of corticosteroid secretion without any apparent tachyphylaxis. During prolonged administration of galanin (10(-6) M), the steroidogenic effect of ACTH (10(-9) M) was significantly reduced. In contrast, galanin did not attenuate the stimulation of corticosteroid secretion induced by the angiotensin II analog [Sar1,Val5]angiotensin II. These results show the occurrence of galanin in fibers innervating the frog adrenal gland. The data also demonstrate that synthetic galanin inhibits spontaneous and ACTH-induced corticosteroid release. Taken together, these findings suggest that galanin, released by nerve fibers in the adrenal tissue, can act locally as a modulator of steroid secretion.

New types of primers (stair primers) for PCR amplification of the variable V3 region of the human immunodeficiency virus

The aim of the study was to develop a reliable PCR method for the detection of viral genomes with frequent mutations like HIV and hepatitis C virus. A system of 'stair' primers is suggested which allows amplification of a genomic sequence despite the presence of mutations in the region of the primers. In this system, classical primers are replaced with primers composed of a mixture of equimolar oligonucleotides in which the 5' end remains constant (single sized fragment) and the 3' end is displaced base by base. By PCR, 'stair' primers (HIV set) were compared to single-sequence primers of 20 and 25 nucleotides chosen in the same hypervariable region of the HIV gp120 (on both sides of V3 region), as well as to classical primers chosen in the conserved pol (polV2) and gag (SK38-39) regions of the genome. Of 17 HIV isolates obtained by co-culture of lymphocytes from HIV-seropositive patients, 17/17 (100%) were amplified using stair primers, 14/17 (82%) with 25-nucleotide primers, and 12/17 (70%) with 20-nucleotide primers. Amplification occurred in 17/17 instances with polV2 primers and in 16/17 instances with SK38-39. In addition, 55 other isolates were tested comparatively using stair, polV2 and SK38-39 primers. All isolates were amplified using stair and SK38-39 primers and 54/55 isolates with polV2 primers. When applied to 22 extracts of patients' lymphocytes DNA, stair primers amplified all 22 extracts to the same degree as polV2 and SK38-39, whereas the 20 and 25 nucleotide primers chosen in the variable region were not as reliable. This new primer system allows reliable detection of variable genomic regions of the HIV genome and amplification of such regions directly in patient leukocytes. In addition, the contribution of this system to microbiology and human genetics in general may be important.

The prognostic value of plasma viremia in HIV-infected patients under AZT treatment: a two-year follow-up study

To determine the prognostic value of plasma viremia in long-term zidovudine (AZT)-treated HIV-infected patients, HIV-1 plasma viremia (PV) was quantified in 28 HIV-infected patients before and during AZT long-term treatment; the follow-up also included p24 antigenemia and CD4 cell counts. The variations of these markers during the follow-up period, the correlation with the clinical outcome (progressors versus nonprogressors), and the discrepancies between PV and surrogate markers were then analyzed. A significant and stable decrease in PV titer was observed in only nonprogressors (Friedman test, p < 0.005). At the end of follow-up, 11 (73%) of the 15 non-progressors were PV responders (patients who remained or became PV- long-term), whereas all the 13 progressors were PV nonresponders (patients who remained or became PV+). These results indicated a strong correlation between PV and clinical outcome (Fischer's exact test, p < 0.0001). The persistence, increase, or reappearance of viral replication appeared to be an important predictor of poor clinical outcome in HIV-infected patients under AZT treatment. This finding could provide a rational basis to help the clinician's decision in the clinical treatment of HIV-infected patients.

Inhibition of intracellular growth of Listeria monocytogenes by antibiotics

We studied the activities of 15 antibiotics on the intracellular growth of Listeria monocytogenes in a HeLa cell line. After 24 h of contact with the infected cells, the antibiotics most effective against the intracellular growth of the 10 strains tested were amoxicillin, temafloxacin, and sparfloxacin, which nevertheless failed to totally eliminate the intracellular bacteria. Rifampin and co-trimoxazole had variable effects, depending on the isolates studied. The most active combinations were amoxicillin-sparfloxacin, co-trimoxazole-gentamicin, and sparfloxacin-co-trimoxazole. The results suggest the value of using a cell culture technique to study the activities of antibiotics against certain bacteria with intracellular sites of multiplication.

Sustained bacteremia in 26 patients with a permanent endocardial pacemaker: assessment of wire removal

We reviewed the data on 26 patients with permanent endocardial pacemakers who had 28 episodes of bacteremia to determine whether removal of the wire is required. Patients recovered completely from the first episode in seven of 20 cases of staphylococcal bacteremia and in six of six cases of nonstaphylococcal bacteremia (P = .015). Definitive cure was not achieved during the first episode in seven cases of staphylococcal bacteremia related to the pacing system when the wire was not withdrawn; however, cure was achieved in five of six cases when the whole pacemaker was removed (P < .01). The duration of treatment was longer for the patients from whom the wire was not removed during the first episode (P < .01). Whether cases of staphylococcal bacteremia were related to the pacing system or not, the rate of recovery of the responsible microorganism from the wires was similar for both groups of patients (six [82%] of seven and three [75%] of four, respectively). Nonstaphylococcal bacteremia was unrelated to the pacing system in five of six cases; these patients were all cured without removal of the wire.

Fatal co-infection with pulmonary tuberculosis and herpes simplex virus 1 pneumonia under steroid treatment

We report a case of adult respiratory distress syndrome in a 65 yr old man under inappropriate steroid therapy who developed both Herpes simplex virus 1 (HSV) and Mycobacterium tuberculosis pneumonia; we conclude from clinical and histological data that HSV 1 played a major role in the fatal outcome of this immunocompromised patient, in spite of acyclovir treatment.

Fatal co-infection with pulmonary tuberculosis and herpes simplex virus 1 pneumonia under steroid treatment

We report a case of adult respiratory distress syndrome in a 65 yr old man under inappropriate steroid therapy who developed both Herpes simplex virus 1 (HSV) and Mycobacterium tuberculosis pneumonia; we conclude from clinical and histological data that HSV 1 played a major role in the fatal outcome of this immunocompromised patient, in spite of acyclovir treatment.

Thrombotic thrombocytopenic purpura with the acquired immunodeficiency syndrome: a pathologically documented case report

We report a patient with the acquired immunodeficiency syndrome (AIDS) in whom the acute onset of neurologic disorders and renal failure could be attributed to thrombotic microangiopathy. Clinical, biological, and pathological features were compatible with the diagnosis of thrombotic thrombocytopenic purpura (TTP). Such cases have been previously described, but histologically documented case reports are uncommon.

[Nosocomial urinary tract infection]

Care for asepsis and the use of a closed drainage system reduce the risk of urinary tract infection with indwelling catheter. Beyond a few days, infection will still end to occur, earlier in female and diabetic patients. Local or systemic antimicrobials have neither prophylactic nor even therapeutic actual usefulness, as long as infection remain asymptomatic, which is by far the most frequent situation. Thus, repeated cultures of urine samples are needless. Treatment should be applied to symptomatic infection. The risk for infection is lower in case of intermittent catheterization, with the use of a penilex or a percutaneous bladder catheter. Some instrumental procedures of surgical techniques require short-term antimicrobial prophylaxis: prostatic endoscopic resection, transperineal or transrectal prostatic biopsy, percutaneous nephrolithotomy, prostatectomy, cystectomy, prostheses implantation.

[Water intoxication in psychiatric patients. 13 cases of severe hyponatremia]

Water intoxication mostly occurs in psychiatric patients. We observed 13 episodes of severe hyponatremia (less than 120 mmol/l) following a period of increased water consumption in 10 psychiatric patients (5 men, 5 women, mean age 48.8 years) treated with neuroleptics and/or benzodiazepines. Other causes of hyponatremia were excluded. The initial clinical signs were associated with severe gastrointestinal and neurological disorders requiring intensive care. In every case a gradual return to normal of natremia was obtained by creating a negative water balance while compensating for the sodium loss. From a study of urine and plasma osmolality ratio (U/P osm) on admission, several physiopathological mechanisms could be envisaged. A U/P osm ratio lower than 1 (6 cases) suggested a water intake exceeding the maximum dilution capacity of the kidneys (20-25 1), or a lesser water intake with little or no osmolal intake, or again an intrarenal disorder of urine dilution. When the U/P osm ratio was higher than 1 (7 cases), reflecting inappropriate secretion of the antidiuretic hormone, the hyponatremia could be explained by the psychosis itself, the treatment taken by the patients, a disorder of thirst regulation and/or a non-osmotic stimulation of vasopressin. This population, therefore, was heterogeneous: the mechanisms which contribute to this pathology are not fully elucidated, and they probably involve several factors.

[Pharmacokinetics of ceftriaxone in intensive care]

Pharmacokinetic parameters of ceftriaxone were studied on day 1 and 5 in 21 patients admitted in an ICU for severe infections. All patients received a single daily infusion of 2 g of ceftriaxone during 15 minutes. We have determined the ratio to the daily dose of serum ceftriaxone concentrations (peak level and trough level) and of areas under the curve. According to renal function and the existence of cholestasis, the results of our study showed: 1) In patients with creatinine clearance greater than 10 ml/mn and without cholestasis, a single daily infusion of 2 g ceftriaxone achieves therapeutic blood levels without any accumulation phenomenon. 2) In patients requiring hemodialysis without cholestasis, the period between two 2 g doses should be prolonged to 48 h. 3) Marked cholestasis and creatinine clearance greater than 10 ml/mn prolong the elimination half-life of ceftriaxone leading to an interval extension of the single dose of 2 g. Further investigations are needed in the latter situation.

[What has become of preliminary transfusion protocols in kidney transplantation?]

Many studies have demonstrated that pretransplant blood transfusions improved cadaver kidney graft outcome. The nature and the frequency of transfusions-induced lymphocytotoxic antibodies depends of sex, previous pregnancies and kidney grafts, and transfusional patterns. This provoked immunisation is not a hindrance to beneficial effects of transfusions. Numerous reports have investigated the responsible mechanism for this effect. Controversial data concern the optimum number of blood units. In a previous prospective study in patients who received anti-lymphocyte globulins as part of immunosuppressive therapy, we have shown that a multiple transfusions policy does not give better results than only one. Recently, the beneficial effect of transfusions has been questioned, either entirely, or for particular patients according to age, sex, immunosuppressive treatment including cyclosporin or not. This leaded us to reassess benefits of transfusions.

Increase in blood plasma levels of boron and strontium in hemodialyzed patients

Boron and strontium concentrations in blood plasma of controls and hemodialyzed patients from two Centers were determined by inductively coupled plasma emission spectrometry. Boron concentrations in blood plasma were respectively, in controls 2.6 +/- 0.9 mumol/l and in hemodialyzed patients 16.1 +/- 5.6 mumol/l before the dialysis session and 9.5 +/- 3.2 mumol/l at the end. The decrease in blood plasma during the dialysis was concomitant with an increase in the dialysis fluid (1.2 +/- 0.7 mumol/l at the beginning and 4.6 +/- 1.8 mumol/l at the end). Strontium concentrations in blood plasma were respectively, in controls 0.22 +/- 0.06 mumol/l and in hemodialyzed patients 0.62 +/- 0.24 mumol/l before the dialysis session and 0.64 +/- 0.14 mumol/l at the end. The mean concentration of strontium in the dialysis fluid was the same before (0.49 +/- 0.11 mumol/l) and after the dialysis session (0.49 +/- 0.10 mumol/l), but a transfer between plasma and dialysis fluid was shown by individual changes. Some considerations about these results are put forward but their possible clinical consequences are not yet known.

Blood plasma fluoride in haemodialysed patients

Blood plasma fluoride was determined in 15 chronic haemodialysed patients (60.2 +/- 7.2 yr old) before and after a 4-h dialysis using dialysates with very low fluoride level, and in two control groups, the first of 20 healthy younger subjects (45.9 +/- 3.4 yr old), the second of 8 healthy older subjects (69.1 +/- 6.8 y old). Before haemodialysis the fluoride concentration (1.31 +/- 0.31 mumol/l; 24.8 +/- 5.9 micrograms/l), was higher than in both control groups (0.35 +/- 0.16 mumol/l; 6.6 +/- 3.1 micrograms/l and 0.44 +/- 0.16 mumol/l 8.4 +/- 3.0 micrograms/l, respectively). During dialysis, the mean fluoride concentration fell to 0.94 +/- 0.26 mumol/l, remaining however, significantly higher than in control subjects. The use of fluoride-free dialysates seems to partially compensate the effect of renal impairment since plasma fluoride is only moderately increased in these patients.