The Association of HIV-1 Neutralization in Aviremic Children and Adults with Time to ART Initiation and CD4+/CD8+ Ratios

Broadly neutralizing antibodies (bnAbs) bind and neutralize diverse HIV isolates and demonstrate protective effects in primate models and humans against specific isolates. To develop an effective HIV vaccine, it is widely believed that inducing these antibodies is crucial. However, the high somatic hypermutation in bnAbs and the limited affinity of HIV Env proteins for bnAb germline precursors suggest that extended antigen exposure is necessary for their production. Consequently, HIV vaccine research is exploring complex sequential vaccination strategies to guide the immune response through maturation stages. In this context, the exploration of the factors linked to the generation of these antibodies across diverse age groups becomes critical. In this study, we assessed the anti-HIV-1 neutralization potency and breadth in 108 aviremic adults and 109 aviremic children under 15 years of age who were receiving ART. We used a previously described minipanel of recombinant viruses and investigated the factors associated with neutralization in these individuals. We identified individuals in both groups who were capable of neutralizing viruses from three different subtypes, with greater cross-neutralization observed in the adult group (49.0% vs. 9.2%). In both groups, we observed an inverse association between neutralization breadth and the CD4+/CD8+ ratio, as well as a direct association with the time to ART initiation. However, we found no association with time post-infection, cumulative ART duration, or CD8+ cell levels. The present study demonstrates that children receiving antiretroviral therapy generate broadly neutralizing responses to HIV-1, albeit with lower magnitude compared to adults. We also observed that neutralization breadth is associated with CD4+/CD8+ levels and time to treatment initiation in both children and adults living with HIV-1. Our interpretation of these results is that a delay in ART initiation could have prolonged the antigenic stimulation associated with viral replication and thus facilitate the capacity to elicit long-lasting broadly neutralizing responses. These results corroborate prior findings that show that HIV-1-neutralizing responses can persist for years, even at low antigen levels, implying an HIV-1 vaccine may induce lasting neutralizing antibody response.

Evaluation of the Thermal Stability of a Vaccine Prototype Based on Virus-like Particle Formulated HIV-1 Envelope

The long-term storage stability of vaccines has a major impact on the roll-out and success of global immunization programs. For the Human Immunodeficiency Virus type 1 (HIV-1) virus-like particle (VLP) vaccine prototype evaluated here, nanoparticle tracking analysis (NTA), and enzyme-linked immunoabsorbent assay (ELISA) results demonstrated a remarkable structural stability. VLPs maintained their integrity and the recognition of relevant B-cell epitopes for three months at 4 and −20 °C. Interestingly, most particles remained intact and preserved the recognition of relevant epitopes even after a week of storage at room temperature.

Guiding the humoral response against HIV-1 toward a MPER adjacent region by immunization with a VLP-formulated antibody-selected envelope variant

Preventive HIV-1 vaccine strategies rely on the elicitation of broadly neutralizing antibody (bNAb) responses, but their induction in vivo by vaccination remains challenging. Considering that the ability of an epitope to elicit effective humoral immunity depends on its exposure on the virion, we have used a reverse genetics approach to select variants from an HIV-1 AC10_29 randomly mutated envelope library that showed increased affinity for a selected bNAb (4E10 bNAb targeting the HIV-1 MPER region). Isolated envelope sequences were analyzed by deep-sequencing showing a small number of dominant changes, including the loss of four potential N-linked glycosylation sites and disruption of the V1/V2 loop. Accordingly, the dominant variant (LR1-C1), showed not only increased affinity for MPER bNAbs 4E10 and 2F5, but also higher affinity for an additional antibody targeting the V3 loop (447-52D) that could be a consequence of an open conformation tier 1-like Env. Furthermore, the amino acids specific for the selected variant are associated with an increased sensitivity for 4E10 and 2F5 antibodies. In vivo studies showed that sera from mice immunized with LR1-C1 viruses possessed an improved neutralizing activity compared to the wild-type AC10_29 env. While Virus Like Particles (VLPs) carrying this envelope were unable to induce detectable neutralizing activity in immunized rabbits, one animal showed antibody response to the 4E10-proximal region. Our data establish a novel approach that has the potential to yield HIV envelope immunogen sequences that direct antibody responses to specific envelope regions.

Antibody-Based Preventive and Therapeutic Strategies Against HIV

BACKGROUND

Over the years, numerous studies have been carried out demonstrating the role of antibodies in HIV control leading to the development of antibody-based therapeutic and prophylactic strategies.

OBJECTIVE

The objective of this review is to provide updated information on the role of antibodies in the prevention and control of HIV infection and the strategies against HIV that have been designed based on this information.

RESULTS

Passive transfer of anti-HIV antibodies in animal models has proven the efficacy of certain antibodies in the prevention and treatment of infection. The capacity of antibodies to control the virus was first attributed to their neutralizing capacity. However, we now know that there are other Fc-mediated antibody activities associated with virus protection. When it comes to better understanding protection against HIV, we ought to pay particular attention to mucosal immune responses. The evidence accumulated so far indicates that an effective vaccine against HIV should generate both mucosal IgAs and systemic IgGs. Due to the problematic induction of protective anti-HIV antibodies, several groups have developed alternative approaches based on antibody delivery via gene therapy vectors. Experiments in animal models with these vectors have shown impressive protection levels and this strategy is now being clinically trialed.

CONCLUSION

Taking into account all the information included in this review, it seems evident that anti-HIV-1 antibodies play an important role in virus control and prevention. This review aims to give an overview of the strategies used and the advances in antibody-based preventive and therapeutic strategies against HIV-1.

Definition of an 18-mer Synthetic Peptide Derived from the GB virus C E1 Protein as a New HIV-1 Entry Inhibitor

BACKGROUND

A slower progression of AIDS and increased survival in GBV-C positive individuals, compared with GBV-C negative individuals has been demonstrated; while the loss of GBV-C viremia was closely associated with a rise in mortality and increased progression of AIDS. Following on from the previous reported studies that support the thesis that GBV-C E2 interferes with HIV-1 entry, in this work we try to determine the role of the GBV-C E1 protein in HIV-1 inhibition.

METHODS

The present work involves the construction of several overlapping peptide libraries scanning the GBV-C E1 protein and the evaluation of their anti-HIV activity.

RESULTS

Specifically, an 18-mer synthetic peptide from the GBV-C E1 protein, E1(139-156), showed similar antiviral activity against HIVs from viruses from clades A, B, C, D and AE. Competitive ELISA using specific gp41-targeting mAbs, fluorescence resonance energy transfer as well as haemolysis assays demonstrated that this E1 peptide sequence interacts with the highly conserved N-terminal region of the HIV-1 gp41 (the fusion peptide) which is essential for viral entry.

CONCLUSIONS

We have defined a novel peptide lead compound and described the inhibitory role of a highly conserved fragment of the E1 protein.

GENERAL SIGNIFICANCE

The results together allow us to consider the non-pathogenic E1 GBV-C protein as an attractive source of peptides for the development of novel anti-HIV therapies.

HIV-1 Dual Infected LTNP-EC Patients Developed an Unexpected Antibody Cross-Neutralizing Activity

This study evaluated the neutralization breadth in dually infected (DI) HIV-1 long-term non-progressor elite controller patients (LTNP-EC) using a representative minipanel of 6 viruses from 5 different subtypes. Our results showed an improved neutralization breadth in DI LTNP-EC patients when compared with matched LTNP single-infected patients. The role of viral diversity in neutralization was estimated with the Shannon Entropy and the p-distance in viral quasispecies. We found a positive correlation between neutralization breadth and diversity within the viral quasispecies. This correlation could explain why a group of LTNP-EC patients developed a broad neutralizing response despite having undetectable levels of viremia.

Glycosystems in nanotechnology: Gold glyconanoparticles as carrier for anti-HIV prodrugs

The therapeutic approach for the treatment of HIV infection is based on the highly active antiretroviral therapy (HAART), a cocktail of antiretroviral drugs. Notwithstanding HAART has shown different drawbacks like toxic side effects and the emergence of viral multidrug resistance. Nanotechnology offers new tools to improve HIV drug treatment and prevention. In this scenario, gold nanoparticles are an interesting chemical tool to design and prepare smart and efficient drug-delivery systems. Here we describe the preparation and antiviral activity of carbohydrate-coated gold nanoparticles loaded with anti-HIV prodrug candidates. The nucleoside reverse transcriptase inhibitors abacavir and lamivudine have been converted to the corresponding thiol-ending ester derivatives and then conjugated to ~3 nm glucose-coated gold nanoparticles by means of "thiol-for-thiol" ligand place exchange reactions. The drugs-containing glyconanoparticles were characterized and the pH-mediated release of the drug from the nanoparticle has been determined. The antiviral activity was tested by evaluating the replication of NL4-3 HIV in TZM-bl infected cells. The proof-of-principle presented in this work aims to introduce gold glyconanoparticles as a new multifunctional drug-delivery system in the therapy against HIV.

Vector-mediated gene transfer engenders long-lived neutralizing activity and protection against SIV infection in monkeys

The holy grail for HIV vaccine development is an immunogen that elicits persisting antibodies with broad neutralizing activity against field strains of the virus. Unfortunately, very little progress has been made in finding or designing such immunogens. Using the SIV model, we have taken a markedly different approach: delivery of an adeno-associated virus (AAV) gene transfer vector to muscle for the expression of antibodies or antibody-like immunoadhesins having predetermined anti-SIV specificity. With this approach, anti-SIV molecules are endogenously synthesized in myofibers and passively distributed to the circulatory system. Using such an approach in monkeys, we have now generated long-lasting neutralizing activity in serum and observed complete protection against intravenous challenge with virulent SIV. In essence, this strategy bypasses the adaptive immune system and holds significant promise as a novel approach to an effective HIV vaccine.

Balancing selection and the evolution of functional polymorphism in Old World monkey TRIM5alpha

Retroviral restriction factor TRIM5alpha exhibits a high degree of sequence variation among primate species. It has been proposed that this diversity is the cumulative result of ancient, lineage-specific episodes of positive selection. Here, we describe the contribution of within-species variation to the evolution of TRIM5alpha. Sampling within two geographically distinct Old World monkey species revealed extensive polymorphism, including individual polymorphisms that predate speciation (shared polymorphism). In some instances, alleles were more closely related to orthologues of other species than to one another. Both silent and nonsynonymous changes clustered in two domains. Functional assays revealed consequences of polymorphism, including differential restriction of a small panel of retroviruses by very similar alleles. Together, these features indicate that the primate TRIM5alpha locus has evolved under balancing selection. Except for the MHC there are few, if any, examples of long-term balancing selection in primates. Our results suggest a complex evolutionary scenario, in which fixation of lineage-specific adaptations is superimposed on a subset of critical polymorphisms that predate speciation events and have been maintained by balancing selection for millions of years.

A comparative immunogenicity study in rabbits of disulfide-stabilized, proteolytically cleaved, soluble trimeric human immunodeficiency virus type 1 gp140, trimeric cleavage-defective gp140 and monomeric gp120

The human immunodeficiency virus type 1 (HIV-1) surface envelope glycoprotein (Env) complex, a homotrimer containing gp120 surface glycoprotein and gp41 transmembrane glycoprotein subunits, mediates the binding and fusion of the virus with susceptible target cells. The Env complex is the target for neutralizing antibodies (NAbs) and is the basis for vaccines intended to induce NAbs. Early generation vaccines based on monomeric gp120 subunits did not confer protection from infection; one alternative approach is therefore to make and evaluate soluble forms of the trimeric Env complex. We have directly compared the immunogenicity in rabbits of two forms of soluble trimeric Env and monomeric gp120 based on the sequence of HIV-1(JR-FL). Both protein-only and DNA-prime, protein-boost immunization formats were evaluated, DNA-priming having little or no influence on the outcome. One form of trimeric Env was made by disrupting the gp120-gp41 cleavage site by mutagenesis (gp140(UNC)), the other contains an intramolecular disulfide bond to stabilize the cleaved gp120 and gp41 moieties (SOSIP.R6 gp140). Among the three immunogens, SOSIP.R6 gp140 most frequently elicited neutralizing antibodies against the homologous, neutralization-resistant strain, HIV-1(JR-FL). All three proteins induced NAbs against more sensitive strains, but the breadth of activity against heterologous primary isolates was limited. When antibodies able to neutralize HIV-1(JR-FL) were detected, antigen depletion studies showed they were not directed at the V3 region but were targeted at other, undefined gp120 and also non-gp120 epitopes.

Simian immunodeficiency virus engrafted with human immunodeficiency virus type 1 (HIV-1)-specific epitopes: replication, neutralization, and survey of HIV-1-positive plasma

To date, only a small number of anti-human immunodeficiency virus type 1 (HIV-1) monoclonal antibodies (MAbs) with relatively broad neutralizing activity have been isolated from infected individuals. Adequate techniques for defining how frequently antibodies of these specificities arise in HIV-infected people have been lacking, although it is generally assumed that such antibodies are rare. In order to create an epitope-specific neutralization assay, we introduced well-characterized HIV-1 epitopes into the heterologous context of simian immunodeficiency virus (SIV). Specifically, epitope recognition sequences for the 2F5, 4E10, and 447-52D anti-HIV-1 neutralizing monoclonal antibodies were introduced into the corresponding regions of SIVmac239 by site-directed mutagenesis. Variants with 2F5 or 4E10 recognition sequences in gp41 retained replication competence and were used for neutralization assays. The parental SIVmac239 and the neutralization-sensitive SIVmac316 were not neutralized by the 2F5 and 4E10 MAbs, nor were they neutralized significantly by any of the 96 HIV-1-positive human plasma samples that were tested. The SIV239-2F5 and SIV239-4E10 variants were specifically neutralized by the 2F5 and 4E10 MAbs, respectively, at concentrations within the range of what has been reported previously for HIV-1 primary isolates (J. M. Binley et al., J. Virol. 78:13232-13252, 2004). The SIV239-2F5 and SIV239-4E10 epitope-engrafted variants were used as biological screens for the presence of neutralizing activity of these specificities. None of the 92 HIV-1-positive human plasma samples that were tested exhibited significant neutralization of SIV239-2F5. One plasma sample exhibited >90% neutralization of SIV239-4E10, but this activity was not competed by a 4E10 target peptide and was not present in concentrated immunoglobulin G (IgG) or IgA fractions. We thus confirm by direct analysis that neutralizing activities of the 2F5 and 4E10 specificities are either rare among HIV-1-positive individuals or, if present, represent only a very small fraction of the total neutralizing activity in any given plasma sample. We further conclude that the structures of gp41 from SIVmac239 and HIV-1 are sufficiently similar such that epitopes engrafted into SIVmac239 can be readily recognized by the cognate anti-HIV-1 monoclonal antibodies.

Confronting and eradicating an epidemic of bacteraemia

Obtaining vascular access by catheterisation is a good option, especially in patients with vascular system fragility. In the authors' department, there was an increase in Gram Negative Bacillus (GNB) infection in patients with long term catheters (LTC). An objective was set to design an action plan and a new working methodology in order to eradicate the infection and the cause. Three periods were established in the prospective follow-up of LTC patients: the pre-epidemic period (01/94 to 03/99), with a bacteraemia every 144 days per patient, the epidemic period (04/99 to 12/00) with a bacteraemia every ten days per patient, and the post-epidemic period (01/01 to 04/02). A multidisciplinary working group was established, which produced action plans for nursing and technical staff. The working methodology of the service was studied and analysed by means of a review. The deionised water cultures at the entrance to the haemodialysis ward were negative. The dialysis and connector cultures were positive for GNB, confirming that they were of the same genetic origin. An evaluation of the periods was carried out, studying the working methodology, to which no changes were made between the pre-epidemic and epidemic period. In the post-epidemic period, a number of changes were made to the care dynamic, with no other bacteraemia arising to date. Adapting and improving protocols is a good indicator of quality. The role of nursing staff is vital in prevention of GNB.

[An outbreak of gram-negative bacteremia (GNB), especially enterobacter cloacae, in patients with long-term tunnelled haemodialysis catheters]

Vascular access through a venous catheter for haemodialysis is associated with increased risk of thrombosis, central venous stenosis, short access survival and inadequate dialysis. The most important catheter-related complications, which determine method survival, are infection and dysfunction. In particular, infectious episodes are in some studies the leading cause for untimely catheter removal and for catheter-related morbidity but also for morbidity in dialysis patients. Double-lumen central venous catheters used for haemodialysis, are common causes of septicaemia. Most cases are caused by staphylococci. Episodes of gram-negative bacteriemia have been traced to bacterial contamination of water and/or dialysate, errors in dialyzer reprocessing, and improper setup procedures. In this paper, we describe and outbreak of gram-negative bacteremia, firstly E. cloacae, in an outpatients haemodialysis unit, in the patients with long-term tunnelled haemodialysis catheters. We describe the epidemic investigation that we achieved to identify the source of contaminating bacteria and the route by which bacteria gained access to the bloodstream. We prove the contamination by gram-negative bacterium of the water-distribution lines and haemodialysis machines. Moreover, E. cloacae strains isolated from the lines and machines are genotypically identical to the isolated from the patients. Also, we prove that the hands of health care personnel are unintentional carriers. The outbreak was finished when decontamination of dialysis machines was enhanced and dialyzer-priming fluid was modified.

Virus population dynamics, fitness variations and the control of viral disease: an update

Viral quasispecies dynamics and variations of viral fitness are reviewed in connection with viral disease control. Emphasis is put on resistance of human immunodeficiency virus and some human DNA viruses to antiviral inhibitors. Future trends in multiple target antiviral therapy and new approaches based on virus entry into error catastrophe (extinction mutagenesis) are discussed.

Frequency-dependent selection in human immunodeficiency virus type 1

Genetic variation is the main evolutionary strategy adopted by RNA viruses and retroviruses. Evolution operates through competition between different individuals in the same environment, resulting in the imposition of the fittest variant. The process of competition could be affected by various factors, including the frequency of the different competing individuals. In order to investigate this aspect, individual virus populations derived from a human immunodeficiency virus type 1 isolate were studied at different competing proportions. The dynamics of variant imposition in each competition experiment permitted the detection of frequency-dependent selection (FDS); i.e. the imposition of variants is related to their biological fitness, which is also affected by the proportions at which they compete. The existence of FDS in different viruses with RNA genomes would indicate a general mechanism favouring genetic heterogeneity.

[Patients with end-stage chronic renal insufficiency on programmed withdrawal from dialysis]

The voluntary discontinuation of dialysis by patients is a common mode of death in dialysis programmes. Unfortunately the Spanish experience has not been related in the nephrological literature. Initiation of, and withdrawal from, dialysis pose ethical questions for medicine in the 21st century. The dialysis population is aging and they have multiple medical problems. The choice may be between prolongation of quantity or quality of life. We evaluated a protocol for initiation of dialysis in patients with end stage renal failure and their subsequent withdrawal. We determined the factors predicting withdrawal of dialysis and revised the protocol to take account of these. We carried out an opinion poll of doctors and nurses about the effectiveness of the protocol. We studied prospectively the reasons for death of patients in the last seven years.

RESULTS

Thirty patients were withdrawn from dialysis out of 116 who died during treatment by hemodialysis or continuous ambulatory peritoneal dialysis (CAPD) in the last seven years. Vascular nephropathy is the principal disease predicting withdrawal from dialysis; the main precipitating cause is mental incapacity. The availability of a protocol for withdrawal of dialysis is well received by doctors and nurses and it engenders moral and legal calm when facing difficult decisions. Twenty-six per cent of deaths on regular dialysis are the result of withdrawal of treatment.

Unusual distribution of mutations associated with serial bottleneck passages of human immunodeficiency virus type 1

Repeated bottleneck passages result in fitness losses of RNA viruses. In the case of human immunodeficiency virus type 1 (HIV-1), decreases in fitness after a limited number of plaque-to-plaque transfers in MT-4 cells were very drastic. Here we report an analysis of entire genomic nucleotide sequences of four HIV-1 clones derived from the same HIV-1 isolate and their low-fitness progeny following 7 to 15 plaque-to-plaque passages. Clones accumulated 4 to 28 mutations per genome, with dominance of A --> G and G --> A transitions (57% of all mutations) and 49% nonsynonymous replacements. One clone-but not three sibling clones-showed an overabundance of G --> A transitions, evidencing the highly stochastic nature of some types of mutational bias. The distribution of mutations along the genome was very unusual in that mutation frequencies in gag were threefold higher than in env. Particularly striking was the complete absence of replacements in the V3 loop of gp120, confirmed with partial nucleotide sequences of additional HIV-1 clones subjected to repeated bottleneck passages. The analyses revealed several amino acid replacements that have not been previously recorded among natural HIV-1 isolates and illustrate how evolution of an RNA virus genome, with regard to constant and variable regions, can be profoundly modified by alterations in population dynamics.

Drastic fitness loss in human immunodeficiency virus type 1 upon serial bottleneck events

Muller's ratchet predicts fitness losses in small populations of asexual organisms because of the irreversible accumulation of deleterious mutations and genetic drift. This effect should be enhanced if population bottlenecks intervene and fixation of mutations is not compensated by recombination. To study whether Muller's ratchet could operate in a retrovirus, 10 biological clones were derived from a human immunodeficiency virus type 1 (HIV-1) field isolate by MT-4 plaque assay. Each clone was subjected to 15 plaque-to-plaque passages. Surprisingly, genetic deterioration of viral clones was very drastic, and only 4 of the 10 initial clones were able to produce viable progeny after the serial plaque transfers. Two of the initial clones stopped forming plaques at passage 7, two others stopped at passage 13, and only four of the remaining six clones yielded infectious virus. Of these four, three displayed important fitness losses. Thus, despite virions carrying two copies of genomic RNA and the system displaying frequent recombination, HIV-1 manifested a drastic fitness loss as a result of an accentuation of Muller's ratchet effect.

Random important alterations in HIV-1 viral quasispecies after antiviral treatment

The evolution of HIV-1 viral populations was studied in a set of MT-2-co-cultured viruses isolated from five patients at the beginning of treatment with zidovudine and after 11-36 months of drug therapy. We first characterized the HIV-1 pol gene to detect the zidovudine-resistance mutations at codons 215 and 219. To analyse the effect that the selective pressure of zidovudine on pol exerted on other genomic regions, we also studied the env gene. The env gene sequence of virus isolated from one individual was unchanged, whereas three other sample pairs had minor alterations in env. In one individual, we detected a significant change in the env gene sequence, and so performed a clonal analysis on viruses isolated before and after treatment. In this individual, the zidovudine-resistant variant that became predominant in the resistant virus population was an undetected minority variant of the viral population before treatment was initiated. These results indicate that the evolution of quasispecies produced by selective pressure on the pol gene from zidovudine treatment could select, in a random process, important changes in other genomic regions; in particular, we describe alterations in the env gene.

Nursing protocol for manipulation of haemodialysis catheters

This study looked at the incidence of infection complications, in relation to central vein catheterisation as a provisional HD access, by means of the establishment of a nursing protocol for the handling of these catheters. Central vein catheterisation is a classical technique in Nephrology.

Estimation of the prevalence of diabetes mellitus diagnosed, and incidence of type 1 (insulin-dependent) diabetes mellitus in the Avila Health Care region of Spain

We studied the prevalence of diabetes mellitus diagnosed in the Avila Health Care region, Spain, based on the prescribed daily dosage (PDD) of insulin (corrected in function of insulin loss (PDDc)) and sulphonureas, from a sample representative of prescribing physicians (A, n = 48) and pharmacies (B, n = 25) in our region. The amounts of the PDDcs of insulin sold during 1989 per 1000 inhabitants/day were 6.06 and 6.20, respectively for the two samples (A and B). The figures for PDDs of sulphonurea/1000 inhabitants/day were 16.25 and 19.16, respectively. We determined the proportion that diabetic patients on diet alone represented in relation to non-insulin treated diabetic patients who visited the only specialized clinic for diabetic patients in our province in 1989. These patients accounted for 40.83% of non-insulin treated diabetic patients. The patients being treated with biguanides or with a combination of anti-diabetic drugs accounted for less than 1% of those treated in the specialized clinic. Taking this into account, the prevalence of diabetes mellitus in Avila was 3.35% (C.I. 95%: 3.10-3.59), according to the sample A and 3.85% (C.I. 95%: 3.50-4.31) according to the sample B. In addition, we studied the hospital admission records during three consecutive years in order to find out the incidence of type 1 insulin-dependent diabetes mellitus (IDDM) below 15 years of age in the Avila Health Care region of Spain. All prescribing physicians that did not work in the Hospital (197 in the rural area and 18 in the urban area) were used as the secondary source for validation of case ascertainment.(ABSTRACT TRUNCATED AT 250 WORDS)

Behaviour modification in obese subjects with type 2 diabetes mellitus

We have followed prospectively, 46 obese, type 2 diabetic patients for a 55-week period, in order to evaluate the efficiency of an educational programme based on behaviour modification to enhance weight loss and changes of other cardiovascular risk factors. No patient received pharmacological treatment during the study. At the end of the follow-up the patients obtained an average weight loss of 9.250 kg (range: 0.500-17.500 kg); the BMI was reduced from 34.2 +/- 0.8 kg/m2 to 30.6 +/- 1.1 kg/m2 (P less than 0.01); fasting serum glucose descended from 7.9 +/- 0.4 to 6.1 +/- 0.5 mM (P less than 0.05); SBP (systolic blood pressure) decreased from 145.7 +/- 3 to 126.4 +/- 5.1 mmHg (P less than 0.01); DBP (diastolic blood pressure) decreased from 83.5 +/- 2.5 to 65 +/- 2.6 mmHg (P less than 0.01); triglyceride levels were lowered from 164.5 +/- 12 to 109.7 +/- 10 mg/dl (P less than 0.01); HDL-cholesterol levels increased from 1.27 +/- 0.05 to 1.53 +/- 0.12 mM (P less than 0.01). Serum glucose 2 h after a 75 g glucose oral load decreased from 14.9 +/- 0.6 to 12.7 +/- 0.9 mM (P less than 0.05) on week 35 of follow-up. Twelve patients no longer presented a diabetic curve (8 normal oral glucose tolerance test (OGTT) curves, and 4 impaired glucose tolerance (IGT) curves). No significant changes in the parameters studied were obtained in the group of patients on conventional treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of weight loss on insulin sensitivity and cardiovascular risk factors in glucose tolerant and intolerant obese subjects

We observed 170 obese patients during 55 weeks in order to study the influence of insulin resistance and insulin sensitivity on cardiovascular risk factors in such patients as well as the changes occurring on these subjects as a result of weight loss. At the beginning of the study, the patients were divided into two groups, according to the results of an oral glucose tolerance test (OGTT) performed with 75 g of glucose: Group A, glucose tolerant subjects (n = 81), Group B, glucose intolerant subjects (n = 89). Initially Group B patients showed higher values for fasting blood glucose, 2 h after OGTT, systolic and diastolic blood pressure, cholesterol, triglycerides and cholesterol/HDL-cholesterol ratio when compared to Group A patients (p less than 0.05). Fasting and 1 h-post glucose load serum insulin levels in both Group A and Group B patients were higher than those found out in non over-weight tolerant subjects, but there were no differences between both groups. The serum glucose descent slope after an insulin tolerance test (ITT) was lower for group B than for group A (p less than 0.05), whereas both groups demonstrated lower descent slopes than non overweight tolerant subjects (p less than 0.05). After a 55 weeks follow-up period, the patients in Group A had lost 4.6 +/- 0.7 kg and those in Group B 6.2 +/- 1.1 kg. In both groups, the values for SBP, DBP, FBG, triglycerides and cholesterol/HDL-cholesterol ratio had dropped significantly, with a rise in the HDL-cholesterol level.(ABSTRACT TRUNCATED AT 250 WORDS)

Association of a thyrotropin-secreting pituitary adenoma and a thyroid follicular carcinoma

The different factors involved as etiological agents in thyroid cancer have in common long term thyroid follicle stimulation. On this base, a patient with a TSH-producing pituitary adenoma could be at high risk for developing thyroid cancer. A patient consulting for a single thyroid nodule was studied in our unit. He was diagnosed as having a TSH-producing pituitary adenoma and the Thyroid nodule was shown to be a follicular carcinoma following removed. We speculate that elevated TSH levels could have contributed to neoplastic transformation of the thyroid in this patient.

Programme of education for obese patients. Preliminary results after one year

We have evaluated the effects of a Programme of education for Obese Patients with a duration of 12 hours on weight loss and the modification of other indices for cardiovascular risk in 88 obese patients, during the first year of therapy. The BMI dropped from 33.1 +/- 0.2 Kg/m2 to 31.7 +/- 0.7 (p less than 0.01) and 30.9 +/- 0.7) (p less than 0.01) at 5 and 10 weeks respectively, stabilizing subsequently at 35 and at 55 weeks. This was accompanied by a decrease of the triglycerides levels (141 +/- 9 vs 111 +/- 6 mg/dl; p less than 0.01) and of the total cholesterol/HDL-cholesterol ratio (4.7 +/- 0.3 vs 4.2 +/- 0.12; p less than 0.05), as well as of the values for systolic blood pressure (143 +/- 3 vs 121 +/- 3 mm Hg; p less than 0.05) and diastolic blood pressure 81 +/- 2 vs 64 +/- 1 mm Hg; p less than 0.01) at the end of the study. In terms of OGTT, initially 23 patients were classified as diabetic (BMI 32 +/- 0.9 Kg/m2), 25 presented intolerance to carbohydrates (BMI 34.1 +/- 1.6 Kg/m2) and 40 were normal (BMI 33.2 +/- 1.2 Kg/m2). The weight loss in the first 5 weeks was less in patients with diabetes then in those with carbohydrate intolerance and in the normal patients (2.2 vs 3.7 vs 5.9 Kg; p less than 0.01). From the 10th week on no differences were recorded.(ABSTRACT TRUNCATED AT 250 WORDS)

[Programs of diabetological education: a basic tool in the treatment of diabetes mellitus]

To assess whether the programs of diabetologic education (PDE) are effective to improve metabolic control in diabetes mellitus, depending on their inclusion in an overall therapeutic program and on the setting where they are imparted (hospital versus primary care center, PCC), we evaluated the changes in the HbA1 values in 230 insulin-treated diabetic patients, after receiving a PDE in a PCC (group A; n = 88) or as hospital inpatients (group B; n = 72) or outpatients (group C; n = 50). The remaining 20 patients (group D) received the same PDE, but their treatment did not depend on our Unit. The initial mean HbA1 levels were significantly reduced 3, 6 and 9 months after the PDE in group A patients (10.6% vs 9.6%, p less than 0.05; vs 9.4%, p less than 0.02; vs 9.1%, p less than 0.01), in group B patients (10.0% vs 9.5%, p less than 0.05; vs 9.1%, p less than 0.05; vs 9.0%, p less than 0.05) and group C patients (10.1% vs 9.5%, p less than 0.05; vs 9.1%, p less than 0.02; vs 8.9, p less than 0.01); however, they did not significantly change in group D patients (10.3% vs 10.7%, vs 10.3%, and vs 10.0%). Mean HbA1 in months 3, 6 and 9 were not different between groups A, B and C, but they were lower (p less than 0.05) than in group D. Our results confirm that PDE and treatment are effective to improve metabolic control in diabetic patients, whereas diabetological education alone is not useful. The place where PDE is given is not determinant for its effectiveness.