Heterologous HIV-2 challenge of rhesus monkeys immunized with recombinant vaccinia viruses and purified recombinant HIV-2 proteins

In an attempt to analyse the role of anti-envelope immunity in the protection of rhesus monkeys against an HIV-2 intravenous challenge, rhesus macaques were immunized twice with recombinant HIV-2 ROD vaccinia viruses (10(8) p.f.u. each) at days 0 and 30, followed by booster injections of purified HIV-2 proteins at months 8, 9, 15 and 27. One group of five macaques was immunized with the Gag, Pol, Vif and Nef antigens, whereas a second group received the same antigens with the addition of HIV-2 Env protein. Eight months after the last boost, the animals were challenged by intravenous injection of 100 AID50 of a monkey PBMC-grown stock of HIV-2 SBL. None of the animals was protected in spite of high humoral immune responses on day of challenge as determined by ELISA and Western Blot assays.

Present status of vaccination against HIV-1 infection

The development of an effective vaccine against the acquired immunodeficiency syndrome (AIDS) is a formidable task. The absence of any documented case of natural recovery from the disease raises the question of whether any vaccine against human immunodeficiency virus (HIV) could possibly be effective in preventing natural transmission of the virus. It also raises the issue of which type of immune response a vaccine should elicit to be protective. Many obstacles have to be overcome, including the considerable antigenic variability of the virus, its intracellular mode of transmission, its mucosal port of entry, and the persistent nature of the infection. The only animal model available for the development of prototype HIV-1 vaccines is the chimpanzee model. Chimpanzees infected with HIV-1 do not develop AIDS but remain persistently infected. This model, therefore, allows one to test for protection from infection, but not for protection from disease.

Ability of linear and cyclic peptides of neutralization antigenic site 1 of poliovirus type 1 to induce virus cross-reactive and neutralizing antibodies

Eight peptides encompassing neutralization antigenic site 1 of poliovirus type 1 (residues 93-103 of VP1) were synthesized in linear or cyclized form and used to immunize rabbits. The resulting anti-peptide antibodies were tested for their ability to react with linear peptide 95-104, with infectious virus D-particles and heated C-particles and for their capacity to neutralize poliovirus infectivity. A good correlation was observed between the ability of different peptide antisera to immunoprecipitate D-particles and neutralize virus infectivity. The peptides that induced a neutralizing antibody response in the highest number of immunized animals contained flanking residues 104-115 in addition to the 93-103 residues of the epitope. However, a high neutralizing antibody titre was also obtained in two of ten animals immunized with peptide 93-104 cyclized via an amide bond between Asp93 and Lys103. It seems, therefore, that, at least in rabbits, the T-cell epitope recently identified in residues 103-115 of VP1 need not be present in the peptide immunogen in order to obtain poliovirus-specific neutralizing antibodies.

Strategically integrating hospital/home care services for improved profitability

Because hospitals and home health agencies have been predominantly separate organizations, coordination of their efforts has not been optimized. However, with the recent proliferation of hospital-based home health agencies, opportunities to integrate these health care service delivery systems have increased. Bethesda Memorial Hospital, Boynton Beach, Fla., is a 362-bed not-for-profit community hospital with a Medicare-certified home health agency organized as a department of the hospital. Until recently, the home health agency was generally perceived as a separate entity whose services were distinct from hospital services. Progress toward integration of hospital and home care services was given impetus through collaboration of the home health agency administrator and a newly appointed director of medical affairs who was given the responsibility as medical director of the home health agency. A prime responsibility of the director of medical affairs was to reduce length of stay and hospital costs through appropriate resource management.

Attenuated Mengo virus as a vector for immunogenic human immunodeficiency virus type 1 glycoprotein 120

Introduction of a sequence encoding 147 amino acids from human immunodeficiency virus type I (HIV-1) strain MN glycoprotein gp120 into the RNA genome of the stably attenuated Mengo virus strain vM16 yielded an infectious recombinant virus, vMLN450, which expressed the heterologous HIV-1 sequence along with the normal Mengo virus proteins. The HIV-1 gp120 sequence, fused to the amino terminus of the short, nonstructural Mengo virus leader polypeptide was recognized by a gp120 V3 loop-specific monoclonal antibody. When inoculated into mice, recombinant virus vMLN450 elicited a high-titer anti-HIV-1 antibody response as well as an HIV-1MN-specific cytotoxic cellular immune response. An anti-HIV-1 antibody response could also be detected in cynomolgus monkeys after a single immunization. We propose that attenuated Mengo virus can serve as an effective expression vector in cell systems and various animal species and offers another approach to the development of new, live recombinant vaccines.

[The use of 2-chloroprocaine for a combined lumbar plexus and sciatic nerve block]

A combination of the lumbar plexus and sciatic nerve blocks using 2-chloroprocaine (2-CP) for unilateral lower extremity anaesthesia was studied. The purpose of this work was to evaluate the efficacy of 2-CP for ambulatory surgery of short duration with this combination of blocks. Twenty-five patients ASA 1 and 2 were studied. The techniques used have been described by Winnie and Labat. A total dose of 60 ml of 2-CP 3% was injected. Latency time before anaesthesia was approximately seven min for the lumbar plexus and 14 min for the sciatic nerve. The mean duration of the motor block was 71 +/- 16 min, 76.8 +/- 15.3 min and 75 +/- 12.7 min for the sciatic, femoral and obturator nerves respectively. The mean duration of the sensory block was 88.7 +/- 20.9 min, 83.3 +/- 16.4, 79.7 +/- 17.8 min and 93.7 +/- 22 min for the sciatic, femoral, obturator and lateral femoral cutaneous nerves respectively. Success rate was 92% and no major complication occurred. We conclude that a combination of the lumbar plexus and the sciatic nerve blocks with 2-CP is a useful technique for ambulatory surgery of short duration.

Programmed cell death and AIDS: significance of T-cell apoptosis in pathogenic and nonpathogenic primate lentiviral infections

We have proposed that inappropriate induction of programmed cell death (PCD) or apoptosis, a physiological cell-suicide process, may play a role in the pathogenesis of AIDS. This model has been supported by several reports of abnormal levels of PCD in vitro in both CD4+ and CD8+ T cells from human immunodeficiency virus type 1 (HIV-1)-infected persons. To further assess the significance of such a process in AIDS pathogenesis, in vitro PCD was compared in HIV-1-infected persons and in various primate models that allow discrimination between pathogenic chronic lentiviral infection either in the same species, such as rhesus macaques infected with different simian immunodeficiency viruses (SIV), or in different species, such as SIV-infected African green monkeys and HIV-1-infected chimpanzees. Abnormal levels of PCD in CD4(+)-T-cell-depleted peripheral blood mononuclear cells (PBMC), containing the CD8+ T cells, were observed in both pathogenic and nonpathogenic models. However, abnormal levels of PCD in the CD8(+)-T-cell-depleted PBMC, containing the CD4+ T cells, was only observed in the two models leading to AIDS: HIV-1-infected persons and rhesus macaques infected with a pathogenic strain of SIV. This suggests that inappropriate T-cell PCD in HIV-1-infected persons involves two distinct processes: one, concerning CD4+ T cells, is closely related to AIDS pathogenesis; and the other, concerning CD8+ T cells, may be a consequence of immune stimulation with no direct link to AIDS pathogenesis.

[Endogenous affective disorder, seasons of birth and photoperiodicity]

In a retrospective study, we compared the months of birth of 3,106 psychiatric inpatients to those of 1,943 surgical patients collected during the same period 1981-1991 in the same hospital, and of a sample of 10,003,572 births in France in 1977-1989. DSM III-R categories were modified so to allow a comparison with former studies, and psychiatric patients were distributed among seven categories: Bipolars (N = 294), Unipolars (N = 287), Neurotic-reactive depressions (N = 582), First Major Depressive episode (N = 214), Schizophrenia (N = 244), Schizo-Affectives (N = 52) and Other Diagnosies (N = 1,433). Months of birth were grouped in quarters and semesters, according to the usual calendar, but also to temperature and the photoperiodic cycle. The main results were: 1. A seasonnality of births in the General Population sample, with a spring maximum (p < 0.001). 2. An absence of deviation from the general population and the surgical sample among Neurotic-reactive Depressions and Other Diagnoses. 3. A deviation from the general population and from other comparison groups (surgical cases and Other Diagnoses) among Unipolars and First Major Depressive Episodes (most of those being late episodes), with a significant excess of births during the "dark" or "cold" season of the year, especially around the winter solstice. The Bipolar group followed the same tendency, though to a lesser degree and for subjects born before 1940 only. The most significant results were found among Unipolars, which differ from the general population either by quarters (p < 0.0005) or by semesters (p < 0.0005) and from surgical cases by quarters (p < 0.01) and by semesters (p < 0.001). The results were similar for First Major Depressive episodes, although this category was theoretically "anosological". As the median age was high in this category, it might group a number of late depressive episodes, near to "involutionnal melancholia". Thus, our results seem to be relevant to the traditional endogenous-psychogenetic dichotomy, with a "cold" or "dark" seasonnality of births in the first case, and no particular seasonnality in the second case. Some former studies showed the same results, but the most significant deviation was found in mania. Our results cannot be explained by differences in the sex-ratio among the categories, and only partially by an age-incidence effect or an age-cohort effect.(ABSTRACT TRUNCATED AT 400 WORDS)

A novel, glycan-dependent epitope in the V2 domain of human immunodeficiency virus type 1 gp120 is recognized by a highly potent, neutralizing chimpanzee monoclonal antibody

An anti-gp120 monoclonal antibody (MAb), C108G (gamma 1, kappa), was isolated from a chimpanzee that had been infected with strain IIIB of human immunodeficiency virus type 1 (HIV-1IIIB) and subsequently immunized with the recombinant glycoprotein rgp160MN. This MAb is specific for the IIIB strain of HIV-1 and related clones and exhibits very potent neutralization of these viruses; e.g., 100% neutralization of approximately 8 x 10(3) infectious units of HXB2 was achieved with 125 ng of C108G per ml. Commensurate with this potent neutralizing activity, the apparent affinity of C108G for rgp160LAI was very high, i.e., approximately 3 x 10(10) liters/mol. The C108G epitope was not destroyed by reduction of gp120 disulfide bonds but was profoundly disrupted by removal of N-linked sugars from gp120. Despite the importance of a glycan(s) in forming the C108G epitope, specific binding of C108G to synthetic peptides overlapping in amino acids 162 to 169 of the V2 region was detected, albeit with an affinity approximately 2,000-fold lower than that of C108G's binding to glycosylated envelope protein. This epitope mapping correlated with results of competition assays using MAbs of known epitope specificities. To our knowledge, this is the first description of an anti-V2 MAb raised in response to HIV-1 infection. Its potent neutralizing activity and epitope specificity indicate that the V2 domain of gp120 may be an effective target of the protective immune response and, therefore, potentially an important component of HIV vaccines.

High prevalence of hepatitis C virus RNA in the supernatant and the cryoprecipitate of patients with essential and secondary type II mixed cryoglobulinemia

Detection of hepatitis C virus RNA by polymerase chain reaction was performed in 26 patients with type II mixed cryoglobulinemia, and compared with anti-HCV antibody detection. The patients were divided into two groups according to etiology: 15 had essential type II mixed cryoglobulinemia and 11 had secondary type II mixed cryoglobulinemia. In the essential type II mixed cryoglobulinemia group, the prevalence of hepatitis C virus RNA detected by polymerase chain reaction was 60% in the supernatant and 93% in the cryoprecipitate. In the secondary type II mixed cryoglobulinemia group the prevalence of hepatitis C virus RNA was 45% in the supernatant and 55% in the cryoprecipitate. The differences between the two groups were not statistically significant. In both patient groups, detection of hepatitis C virus RNA in the cryoprecipitate was the most sensitive test for hepatitis C virus infection. These results suggest that hepatitis C virus might be involved in the origin of mixed cryoglobulinemia.

Posterior approach to the lumbar plexus combined with a sciatic nerve block using lidocaine

A combination of lumbar plexus block, by a posterior technique, and sciatic nerve block can be a useful technique for outpatient anaesthesia. The purpose of this study was to examine the clinical characteristics of these blocks using lidocaine and to measure the serum lidocaine concentrations. Forty-five patients, undergoing lower extremity surgery, were studied. Sciatic nerve and lumbar plexus blocks were made with lidocaine, 680 mg with adrenaline 0.3 mg. For each patient the following data were collected: weight, age, sex, site of surgery, time to perform each block, needle depth, speed of onset of the sensory and motor blocks in the territories of the sciatic, femoral, obturator and lateral cutaneous (sensory) nerves and postoperative analgesic requirements. Lidocaine serum concentrations were measured in ten of these patients at 0, 2, 5, 10, 30, 60, 90 and 120 min after the second block. Analgesia was complete in 88% (40/45) of the patients. The remaining five patients needed analgesics (fentanyl 150 micrograms or less). Despite the high dose of lidocaine, the serum concentrations were within safe limits (mean +/- SD) (CMAX = 3.66 +/- 2.21 micrograms.ml-1). Only one patient had a serum concentration > 5 micrograms.ml-1 (CMAX = 9.54 micrograms.ml-1). This was associated with a contra-lateral extension of the block. We conclude that this combination of blocks is a valuable alternative for unilateral lower extremity anaesthesia. However, clinicians must be aware of the implications of a contra-lateral extension of the block.

Reversed-phase LC assay method for deoxycholate in influenza vaccine

Sodium deoxycholate is used for the disruption of particles in the manufacturing of some influenza vaccines. Residual deoxycholate in inactivated vaccines is currently determined using a labour-intensive colorimetric method which lacks complete specificity. An alternative assay method for residual deoxycholate in vaccine preparations was developed using reversed-phase LC. Cholic acid was used as internal standard and the ratio of internal standard to test solute was used for all calculations. Prior to LC analysis, deoxycholic acid was concentrated by solid-phase extraction, a procedure that also removed proteinaceous material in vaccine samples. The clean-up/concentration procedure recovery was examined using untreated samples and was found to be quantitative. The linearity range of the LC method was between 3 and 200 micrograms ml-1, with a limit of detection of approximately 0.4 micrograms on column, and a lower limit of quantitation of 1.6 micrograms on column. Replicate assays during intra-and inter-day experiments gave acceptable levels of variability. The DCA content of samples from three lots of influenza vaccine varied between 10 and 16 micrograms ml-1. These values were appreciably lower than those measured spectrophotometrically, indicating the higher specificity of the LC method.

Anatomy of the posterior approach to the lumbar plexus block

The purpose of this study was to describe the relation of the lumbar plexus with the psoas major and with the superficial and deep landmarks close to it. Four cadavers were dissected and 22 computed tomography files of the lumbosacral region studied. Cadaver dissections demonstrated that the lumbar plexus, at the level of L5, is within the substance of the psoas major muscle rather than between this muscle and the quadratus lumborum. The femoral nerve lies between the lateral femoral cutaneous and obturator nerves. However, while the lateral femoral cutaneous nerve is in the same fascial plane as the femoral nerve, the obturator nerve can be found in the same plane as the two other nerves or in its own muscular fold. Radiological data provided the following measurements: the femoral nerve is at a depth of 9.01 +/- 2.43 cm; the psoas major medial border is at 2.73 +/- 0.64 cm from the median sagittal plane; and its lateral border is at 6.41 +/- 1.61 cm from the same plane. It is concluded that the lumbar plexus is within the psoas major, that the obturator nerve localization within the psoas major varies and that computed tomography data define precisely the relationship of the lumbar plexus with superficial and deep landmarks.

Synoviorthesis with colloidal 32P chromic phosphate for the treatment of hemophilic arthropathy

Between 1977 and 1992, we performed ninety-two synoviortheses (destruction of synovial tissue by intra-articular injection of a radioactive agent) on forty-eight patients who had a severe congenital disorder of hemostasis and chronic hemophilic synovitis that was resistant to conventional treatment. Colloidal 32P chromic phosphate was injected intra-articularly: 1.0 millicurie for knees and 0.5 millicurie for other joints. The duration of follow-up ranged from one to fifteen years. The frequency and importance of bleeding decreased in most of the patients. The range of motion of half of the joints remained stable or improved and that of the other half continued to decrease. Radiographic scores worsened progressively despite the decreased frequency of hemarthrosis. In most patients, the extra-articular leakage of the radioactive agent was slight. Chromosome breakages were observed almost exclusively in patients who were seropositive for human immunodeficiency virus and in whom the CD4-lymphocyte count was decreased from normal. The patients' level of satisfaction with the results was high.

Percutaneous internal ureteral stent placement: review of technical issues and solutions in 50 consecutive cases

Fifty consecutive percutaneous ureteral stent placements in 40 patients over 2 1/2 years were reviewed. Thirty-seven of 50 cases were performed following failed retrograde stenting. Antegrade stenting failed in 2/37 (5%) cases of malignant obstruction, and 4/13 (31%) cases of benign ureteral disease. Causes of failure and common technical problems included poor angulation of the percutaneous track, tortuous dilated ureters, tight obstructions, wedging of stent assembly components due to high resistance, and difficulty in positioning of the proximal pigtail. Helpful technical modifications included mid-pole rather than lower pole calyceal access, urinary decompression prior to stenting, and the routine use of a peel-away sheath (success rate 23/24 placements with sheath vs 21/26 without sheath). Stent patency rates were 95% at 3 months and 54% at 6 months. With attention to technique and appropriate modifications, success rate of percutaneous stenting remained high in this series despite the large number of cases referred after retrograde stenting had failed.

[Can early recurrent hemorrhage in gastroduodenal ulcer be predicted?]

OBJECTIVE

To evaluate clinical, biological and endoscopic predictive factors of early recurrent bleeding from gastric or duodenal ulcers.

PATIENTS AND METHODS

Seventy six patients (26 females and 50 males) with a mean age of 65.9 years (SD = 17.2) were included in a prospective study. Among the 76 patients, there were 39 NSAIDs users (51.3%). An endoscopy was performed systematically until 12 hours after admission. Treatment modalities were identical for all patients. The predictive value of 11 factors was evaluated through an univariate and multivariate analysis.

RESULTS

Three factors had independent significant predictive value: a) the number of blood units used to treat a shock and to increase the haemoglobin level up to 100 g/L (P < 0.05); b) "high endoscopic risk" of recurrent bleeding including Forrest Ia, IIa and IIb ulcers (P < 0.05); c) a non steroidal anti-inflammatory treatment was associated with no recurrent bleeding contrary to the other factors (P < 0.05). Based on a second multivariate analysis including clinical factors only, a predictive score was calculated: 5 + number of blood units -5 x (NSAID = 0/1). The cut off point with maximum discrimination was 6 (specificity = 79.6%; sensitivity = 77.2%).

CONCLUSION

A combination of clinical and endoscopic factors is useful to predict ulcer recurrent bleeding. Our clinical predictive score is interesting because of its simplicity. Its predictive value is of interest but have to be evaluated in another sample of patients.

Potential use of poliovirus as a vector

The live attenuated Sabin strains of poliovirus have proven their efficacy at inducing a good humoral and secretory antibody response in humans. The extensive characterization of poliovirus neutralization antigenic sites and the atomic resolution of the three-dimensional structure of the viral capsid have enabled the use of the most stably attenuated poliovirus strain (the Sabin type 1 strain) as a vector for the presentation of short foreign antigenic domains in place of one of its own neutralization antigenic sites. The creation of such chimeras has been achieved by manipulating poliovirus infectious cDNA and transfecting the resulting chimeric cDNAs onto susceptible cell cultures. However, this epitope-presentation system has a limitation in terms of the sequence and size of the foreign domain that can be incorporated into the poliovirus capsid without disrupting virus viability. This has led to the construction of poliovirus hybrid genomes bearing insertions of longer heterologous sequences in place of part of the poliovirus structural genes. Upon transfection onto susceptible cells providing the poliovirus structural proteins in trans (e.g. cells previously infected with the Sabin 1 strain), stocks of encapsidated RNA replicons which expressed the foreign protein could be obtained. In addition, viable recombinant viruses bearing insertions of heterologous sequences at various places into the poliovirus genome without deleting poliovirus sequences have been reported. Potential applications of these chimeric and recombinant polioviruses in the engineering of new recombinant vaccines are discussed.

High viral load in lymph nodes and latent human immunodeficiency virus (HIV) in peripheral blood cells of HIV-1-infected chimpanzees

We have examined human immunodeficiency virus type 1 (HIV-1) infection in chimpanzees by analyzing HIV-1 DNA and RNA in lymph nodes and peripheral mononuclear cells (PBMCs). Like certain asymptomatic HIV-infected persons, these chimpanzees had no detectable viral replication in their PBMCs. However, viral replication and a high viral load were observed in the lymphatic tissue. Despite the absence of viral replication in PBMCs, 1/1,000 to 1/10,000 of the PBMCs contained HIV-1 proviral DNA, and HIV transcription could be rapidly induced in these cells in vitro. These results provide direct evidence of cellular latency of HIV in vivo and suggest that HIV infection in chimpanzees may be a useful model for clinical latency of HIV infection in humans.

[A sickle cell homozygote with transfusion deadlock. Favorable outcome with hydroxyurea treatment]

Alloimmunization following multiple transfusions, a frequently observed complication in sickle cell anemia patients, may make subsequent transfusion attempts extremely hazardous. The case of a young woman with sickle-cell anemia is reported; she was hospitalized for the treatment of extensive invalidating leg ulcers. The transfusion program that was initiated as a prerequisite to skin allografts had to be stopped, due to rapid occurrence of multiple alloimmunization. Broad spectrum alloantibodies precluded further selection of compatible blood units. In an attempt to get round this impossibility, a treatment with Hydroxyurea was initiated in order to boost synthesis of F-hemoglobin. After one year under this treatment, the patient's clinical status has clearly improved without requiring any new blood transfusion.

Impact of screening donor blood for alanine aminotransferase and antibody to hepatitis B core antigen on the risk of hepatitis C virus transmission

The transfusion-related risk of transmission of hepatitis C virus (HCV) was evaluated in France for the periods before and after exclusion of donor blood units with the surrogate markers elevated alanine aminotransferase (ALT) levels and antibody to hepatitis B core antigen (anti-HBc). A total of 1,412 blood recipients undergoing surgery were followed up prospectively in the period from 1986 to 1989. The stored serum samples were tested for antibodies to HCV by an enzyme immunoassay (EIA) and the result in reactive sera confirmed by a recombinant immunoblot assay (RIBA). The risk of HCV transmission was estimated by the maximum likelihood method for a subpopulation of 892 recipients divided into three groups. Of 55 (3.9%) EIA positive patients, 56.4% were found to be positive prior to transfusion. HCV seroconversion (positive RIBA) occurred in 22 patients (1.6%). The risk of HCV transmission per 1,000 transfused blood units decreased significantly from 4.11 in Group 1 (receiving non-screened blood) to 3.43 in Group II (receiving ALT screened blood) and to 1.40 in Group III (receiving ALT and anti-HBc screened blood). These results demonstrate that screening of donors for surrogate markers had reduced the risk of HCV transmission before the introduction of a systematic anti-HCV screening policy in France in March 1990.

[The use of magnesium sulfate during surgery of pheochromocytoma: apropos of 2 cases]

Maintenance of haemodynamic stability during anaesthesia for phaeochromocytoma resection is still a challenge. If magnesium sulfate is widely used for the control of arterial pressure during preeclampsia, its use during phaeochromocytoma resection has only been published by one author. We describe two cases where magnesium sulfate is the main agent used to control arterial pressure during resection of a phaeochromocytoma. Magnesium sulfate's hypotensive, antiarrhythmic and antiadrenergic properties are reviewed. The total doses administered were 11 g and 12 g, given as an infusion and boluses. Magnesium sulfate could be part of the anaesthetist's pharmacopoeia during phaeochromocytoma resection.