Lack of evidence of a stable viral load set-point in early stage asymptomatic patients with chronic HIV-1 infection

OBJECTIVE

To address the question of whether individuals with chronic HIV-1 infection have a stable viral load set-point and to assess the influence of host and viral factors on the evolution of viral load in a subset of stable asymptomatic patients with a baseline viral load below 5000 copies/ml and CD4+ T-cell count above 500 x 10(6)/l.

METHODS

Medical visits were performed at least every 6 months including routine blood analysis, viral load and CD4+ T-cell count. HIV-1 RNA was measured in frozen (-70 degrees C) plasma samples using PCR. Patients were classified into three groups according to baseline viral load: group A, < 200 copies/ml (undetectable); group B, 201-2000 copies/ml; group C, 2001-5000 copies/ml. A survival analysis and a Cox regression model were performed to assess the influence of viral and host factors in the increase of baseline viral load. The endpoint was the time to increase viral load to a stable level > 0.5 log10 copies/ml above baseline viral load in groups B and C and to a stable detectable viral load (> 200 copies/ml) in group A.

RESULTS

A cohort of 114 patients with viral load below 5000 copies/ml was followed for a median of 12 months (6-42 months). Overall, 22 (19%) out of 114 patients had an increase > 0.5 log10 copies/ml of baseline viral load. Baseline viral load increased in two (5%) out of 37 patients in group A, four (12%) out of 33 patients in group B, and 16 (36%) out of 44 patients in group C (survival analysis, P<0.002). Patients of group C had a eightfold higher risk of increasing baseline viral load than patients in the other two groups pooled together (hazards ratio, 8.28; 95% confidence interval, 1.78-38; P = 0.006). Patients with an increase of viral load to the virological endpoint had a threefold higher risk of decreasing baseline CD4+ T-cell counts > 100 x 10(6)/I than patients with stable viral load (hazards ratio, 2.78; 95% confidence interval, 1.12-14; P = 0.03).

CONCLUSIONS

In our cohort of chronically HIV-1-infected asymptomatic patients with a baseline viral load < 5000 copies/ml and CD4+ cell count > 500 x 10(6)/l, a true viral load set-point did not seem to exist. Patients with baseline viral load of 2000-5000 copies/ml had an eightfold higher risk of increasing the level of viral load than patients with a baseline viral load below 2000 copies/ml.

Automated simultaneous quantification of the immunosuppressants 40-O-(2-hydroxyethyl) rapamycin and cyclosporine in blood with electrospray-mass spectrometric detection

A new analytical method to quantify 40-O-(2-hydroxyethyl)rapamycin (SDZ RAD) and cyclosporine (Cs) simultaneously in blood is presented. The combination of an on-line solid-phase extraction step with an HPLC system coupled to an electrospray mass spectrometer gave excellent specificity, sensitivity, and reproducibility. Aliquots of deproteinized blood samples were injected into the HPLC system and extracted on-line, using a conventional C18 guard column. The extract was eluted from the guard column in the backflush mode and injected into the liquid chromatography-mass spectrometry system. The calibration functions for SDZ RAD and Cs extracted from blood with added analyte were linear from 0.15 to 30 microg/L (r2 = 0.999) and from 1.5 to 1000 microg/L (r2 = 0.999), respectively. The CVs of peak areas were 6.2% at 10 microg/L SDZ RAD (n = 6) and 6.2% at 100 microg/L Cs (n = 6). Recovery ranged from 84.3% to 102.3% for SDZ RAD and from 81.7% to 92.2% for Cs. The lower limit of detection for both drugs was 0.05 microg/L. A rate of four samples per hour was maintained during the consecutive analysis of SDZ RAD and Cs in >500 blood samples with one single extraction and analytical column. The method described is a powerful tool for the simultaneous determination of SDZ RAD and Cs in blood. It works without time-consuming sample preparation steps and with excellent reproducibility. Because of the detection performance of electrospray mass spectrometry, this system offers flexibility in the working range, which is essential for therapeutic drug monitoring under different conditions.

Nonpigmenting fixed drug eruption due to pseudoephedrine

BACKGROUND

The nonpigmenting fixed drug eruption is a distinctive drug reaction characterized by large, tender and symmetric erythematous plaques that disappear with no residual pigmentation.

METHODS

A case of a non-pigmenting fixed drug eruption due to pseudoephedrine is reported.

RESULT

The reappearance of typical lesions at the same sites after oral challenge with 60 mg pseudoephedrine together with the absence of pigmentation confirm the diagnosis.

CONCLUSION

A new case of proven nonpigmenting fixed drug eruption to pseudoephedrine is described.

Radiographic visualization of patellar tendon grafts for the reconstruction of the anterior cruciate ligament

The new biodegradable interference screws offer very many advantages for anterior cruciate ligament replacement with patellar tendon. However, their radiolucency makes it impossible to identify the anchorage sites. We describe an imaging technique of the plasty and its anchorage sites by means of a radiopaque contrast that is commonly used in radiology (Iopamidol; Bracco, Milan, Italy). It is an easy technique that does not extend the time of surgery, it is harmless, and allows us to identify malpositioning or impingement of the plasty.

Paracetamol (acetaminophen) hypersensitivity

BACKGROUND

Paracetamol (acetaminophen) intolerance can occur in less than 5% of aspirin-sensitive subjects as a result of inhibition of prostaglandin synthesis but hypersensitivity to paracetamol without aspirin sensitivity is rare.

METHODS

We report a case of an acute life-threatening hypersensitivity reaction to paracetamol.

RESULTS

An oral challenge with 125 mg of paracetamol was carried out and followed by generalized anaphylactic reaction. An oral provocation test with 500 mg aspirin was well tolerated in the patient.

CONCLUSION

An acute hypersensitivity reaction to paracetamol is described in this study. The results of the study suggest a real allergic mechanism rather than inhibition of prostaglandin synthesis as responsible.

Unsuspected sources of soybean exposure

BACKGROUND

Hidden allergens in processed foods can provoke severe allergic reactions in sensitive individuals. The presence of soy proteins in typical Spanish sausage products (chorizo, salchichón, mortadella, and boiled ham), doughnut and soup stock cubes has not been reported previously.

METHODS

The present article reports two examples of severe allergic reactions due to the ingestion of foods that unexpectedly contained soybean proteins. Allergollogic study included skin prick tests with the implicated foods and their components, serum specific IgE and bronchial and oral provocation tests.

RESULTS

Skin test, serum-specific IgE, and bronchial and oral challenge tests (the latter, in one patient) were positive against soy and the above mentioned processed foods in which the presence of soybean flour was confirmed.

CONCLUSIONS

This report demonstrates the importance of hidden allergens in allergic reactions to foods and the need to scrutinize closely every food component.

Viral load in asymptomatic patients with CD4+ lymphocyte counts above 500 x 10(6)/l

BACKGROUND

HIV-1-infected patients with a CD4+ lymphocyte count > or = 500 x 10(6)/l may be selected for antiretroviral treatment when viral load is above a given cut-off point.

OBJECTIVES

To assess the stability of viral load measurement at CD4+ T-cell counts above 500 x 10(6)/l, and the proportion of patients selected for treatment if a cut-off point of 10,000 or 30,000 RNA copies/ml is used.

DESIGN AND METHODS

Seventy-eight consecutive asymptomatic antiretroviral-naive HIV-1-infected patients with CD4+ lymphocyte counts > or = 500 x 10(6)/l, presenting for previously scheduled medical visits as outpatients, were enrolled. None of the patients had suffered from symptomatic primary infection or seroconverted within 6 months before enrollment. Two blood samples separated by a 1-month interval [day -30 (screening) and day 0 (enrollment)] were collected in an EDTA tube. Plasma was separated and frozen at -70 degrees C within 4 h of collection. HIV-1 RNA was quantified by polymerase chain reaction. CD4+ T cells were measured by flow cytometry.

RESULTS

Viral load was fairly stable, and only four (13%) out of 30 pairs had a variation > or = 0.5 log10. At day -30 and day 0, log10 HIV RNA levels (mean +/- SD) were 4.24 +/- 0.7 and 4.35 +/- 0.87 log10 copies/ml plasma (P = 0.23). The difference of the mean was -0.11 (95% confidence interval, -0.28 to 0.07). At day 0 (n = 78) mean +/- SD value was 35730 +/- 73700 RNA copies/ml (range, < 200-438480; median, 9331; 25th and 75th percentiles, 1518 and 37193, respectively). In 13 patients (16%) the viral load was < 2000 copies RNA/ml. Seven out of 10 patients, who fulfilled the criteria of long-term non-progressors (LTNP), had viral load > 10,000 RNA copies/ml, and two patients had > 30,000 RNA copies/ml. Only two of the 13 patients with CD4+ T-cell counts > 750 x 10(6)/l had viral load > 10,000 copies/ml.

CONCLUSIONS

A single-point viral load assessment is enough in asymptomatic patients with CD4+ lymphocytes counts > or = 500 x 10(6)/l since plasma HIV RNA measurements obtained 1 month apart are fairly stable. Approximately 25% of these patients (including some patients with LTNP criteria) will be selected for treatment if 30,000 RNA copies/ml is used as cut-off point, and approximately 50% if the cut-off point is 10,000 RNA copies/ml. Viral load > or = 10,000 is very unusual in patients with CD4+ T-cell counts > 750 x 10(6)/l.

[Disability in the private pension system in Chile]

BACKGROUND

The degree of disability of workers ascribed to the private allowances system in Chile, is judged by Medical Commissions that apply norms that establish percentages of incapacity, without considering prognosis.

AIM

To communicate the causes of disability among Chilean workers ascribed to the private allowances system, their mortality and to correlate the causes of death with diagnoses.

SUBJECTS AND METHODS

We analyzed 13,456 consecutive cases judged between August 1990 and April 1992. Mortality was registered up to 12 months after judgment.

RESULTS

Total incapacity was determined in 4,158 cases (30.9%), partial incapacity in 1,340 (9.9%) and minor incapacity in 7,958 (59.1%). Osteoarticular diseases were the main cause of disability in 4,460 patients (33.1%) and 77.8% of patients with malignant tumors were considered as having total incapacity. Mortality was 17% among subjects with total incapacity, 1.5% among those with partial disability and 1% among those with minor disability. The cause of death was related to the main disabling disease in 94% of subjects with total incapacity and 66.6% of those with partial incapacity.

CONCLUSIONS

Osteoarticular diseases are the main cause of inability among workers ascribed to a private pension system.

Neuronal Nicotinic Acetylcholine Receptors in the Brain

Recent molecular, immunologic, and physiological studies have revealed that wide variety of nicotinic acetylcholine receptors exist in the nervous system of vertebrates. Nicotinic systems in the brain appear to play significant roles in drug addiction and in cognitive functions, as well as in pathologies, such as Alzheimer's disease.

Nicotinic receptors in the brain. Molecular biology, function, and therapeutics

Although the psychological and physiological effects of nicotine have long suggested that nicotine exerts specific actions in the brain, the identification of neuronal nicotinic receptors (nAChRs) only began in the past few years with the development of molecular genetics. It is now clear that neuronal nAChRs form a family of highly heterogenous receptor subtypes, as evidenced by the number of genes encoding nAChR subunits, the diversity of immunopurified receptor proteins, and the multiple functional types of ligand-gated ion channels. Neuronal nAChRs have discrete localizations within the brain, and are involved in modulating neuronal firing and transmitter release. Cumulative evidence from animal and human studies indicates that nicotinic systems play a major role in higher cognitive functions and dysfunctions. In particular, the loss of cortical nAChRs is a neuro-chemical hallmark of Alzheimer (AD) and Parkinson (PD) diseases. In addition, nicotine improves memory and attention in Ad and PD. Our recent studies using electrophysiological biochemical and behavioral approaches suggest that the prefrontal cortex is a major target site for the cognitive actions of nicotine.

A pilot case-control study of zidovudine compared with zidovudine plus didanosine in patients with advanced HIV-1 disease and no previous experience with antiretrovirals

Although zidovudine (ZDV) is effective in HIV-1-infected patients, the duration of its efficacy may be short when treatment is started in advanced HIV disease. This pilot prospective case-control study was designed to evaluate the combination of ZDV plus didanosine [ddI] compared with ZDV monotherapy as an initial therapeutic strategy. 'Control' patients (ZDV monotherapy) were matched with 'case' patients (ZDV plus ddI combination therapy) according to the presence or absence of AIDS-defining criteria at entry and CD4 cell count. The case patient group consisted of 35 consecutive HIV-1-infected individuals with < or = 300 CD4 cells/mm3, no previous experience of antiretroviral therapy and who accepted treatment with a combination of ZDV plus ddI. The control patient group consisted of 35 consecutive patients with similar characteristics, but who preferred to start treatment with ZDV alone. Control patients received 250 mg ZDV bid and case patients received ZDV at the same dose plus ddI (200 mg bid). Primary study endpoints were virological (serum HIV-1 RNA) and immunological (CD4 cell count) responses. Viral phenotype (syncytium-inducing (SI) or non-syncytium-inducing (NSI)), development of mutations at codons 215, 41 and 74 and clinical progression (new AIDS-defining event or death) were also assessed. Virological and CD4 cell count responses were significantly greater and more sustained in the group treated with ZDV plus ddI than in the control group, with peak responses of -1.2 +/- 0.7 log10 versus -0.3 +/- 0.4 log10 at 1 month (P = 0.0003) and 61 +/- 52 cells/mm3 versus 19 +/- 25 cells/mm3 at 2 months (P = 0.001), respectively. In both groups the percentage of patients developing a mutation at codon 215 was around 80 per cent at 12 months. A mutation at codon 74 was detected in 30 per cent of case patients at 12 months. Five case patients (14 per cent) versus 12 control patients (34 per cent) showed signs of clinical progression (P = 0.09). In a multivariate model, clinical progression was significantly associated with a baseline

[Functional health patterns and nursing diagnosis in intensive care units]

The evaluation of the critically ill patient to develop a suitable care plan is one of the main objectives of the practices of Medico-Surgery for students of third year of the nursing degree. So as to be able to detect all the needs in the patients and settle priorities in their care we have carried out a physical evaluation and the 11 health functional patterns of Gordon (1982), which has allowed us to formulate the most frequent diagnosis of nursing in the patients hospitalized in the Intensive Care Units of the Hospital Son Dureta of Palma de Mallorca. The collection of data for the evaluation of the patterns of autoperception, adaptation to stress and to the family, has been scarce due to the critical situation of the patient and the tendency of nursing professionals to register the evaluation data which indicate alterations of the physical condition of the patient. The incapacity for self-care and the risk for infection have been the nursing diagnosis which all the patients of this study have shown.

Food-induced and occupational asthma due to barley flour

BACKGROUND

Occupational exposure to inhalant allergens may induce asthma but the presence of asthma after the ingestion of the allergen is rarely reported.

OBJECTIVE

To clarify the clinical relevance of every identified allergen in a patient with respiratory symptoms after exposure to feeding stuffs and cereal flours in his work environment and after ingestion of beverages made of these cereal grains.

METHODS

Case report. Skin prick tests and serum-specific IgE (CAP-FEIA-fluoroenzymeimmunoassay) were used in order to identify specific IgE antibodies. Bronchial provocation tests were performed as an aid in determination of clinical relevance of occupational exposure to the patient's asthma.

RESULTS

A 50-year-old man developed bronchial asthma both after exposure to feeding stuffs and flours and after ingestion of beverages made of cereal flours. Allergy to storage mites (Lepidoglyphus destructor), house dust mites (Dermatophagoides pteronyssinus and farinae), and barley and corn flours were demonstrated by skin testing and serum-specific IgE. Bronchial challenge tests with every allergen showed no response except for an immediate response to barley flour. The most relevant clinical feature was an immediate asthmatic response developed after oral provocation with either barley-made beer or barley flour itself which indicates IgE-mediated, food-induced bronchial asthma (sulfite sensitivity was ruled out).

CONCLUSION

In some particular cases, barley flour may induce bronchial asthma through inhalational and oral routes due to an IgE-mediated mechanism.

Increased serum IgE in alcohol abusers

BACKGROUND

It has been reported that total serum IgE is increased in patients with alcoholic cirrhosis, but it is not clear if this fact is related to alcoholic liver disease or to alcohol intake.

OBJECTIVE

To measure serum IgE in a group of chronic alcoholics with different stages of liver injury in order to elucidate if IgE increase in related to alcoholic liver damage.

PATIENTS AND METHODS

Total serum IgE was determined by enzyme immunoassay in 186 chronic alcoholic patients (137 male/49 female) and 101 healthy controls. Patients and controls with known reasons for IgE elevation were excluded. Among alcoholic patients, 24 had fatty liver, 28 hepatic fibrosis, 29 alcoholic hepatitis, and 67 liver cirrhosis (38 patients were not evaluable concerning liver injury).

RESULTS

Total serum IgE was found to be increased in alcoholics (median 154.5 IU/mL, range 1-7329 IU/mL) with respect to healthy controls (median 20 IU/mL, range < 1-1417 IU/mL) (P < 0.001). IgE increase was moderate (180-1000 IU/mL) in 60 alcoholics (32.3%) and marked ( > 1000 IU/mL) in 27 (14.5%). Male alcoholics had higher IgE levels than females (median 191 IU/mL and range 1-7329 IU/mL vs 105 IU/mL and range 2-2189 IU/mL) ( P = 0.009). On logistic regression analysis, alcoholism, male sex and younger age (but not smoking) were independently associated with higher IgE levels. No clear relationship was noted between serum IgE and severity of alcoholic liver disease. Thus, no correlation was observed between IgE and parameters of liver function (serum bilirubin, albumin or prothrombin index). Likewise, IgE concentrations were not significantly different in patients with liver cirrhosis with respect to patients with less severe liver disease. Serum IgE was increased ( > 180 IU/mL) in 47.8% of cirrhotics and in 44% of patients without liver cirrhosis. In contrast, other immunoglobulins (IgG, IgA and IgM) were significantly correlated with liver dysfunction.

CONCLUSION

Chronic alcoholism should be considered as a cause of increased total serum IgE, regardless of the severity of the underlying liver disease.

[Common health disorders: self-care and self-medication]

SETTING

Community level. "Santa María de Benquerencia" Health District, Toledo.

PARTICIPANTS

People over 15, chosen by random sampling from the municipal census, who stated that they had suffered some health disorder over the previous fortnight.

MEASUREMENTS AND MAIN RESULTS

212 surveys were accepted as valid (average age 42.75, 51.89% male and 48.11% female). 73% had suffered one of the disorders included in the survey during the previous fortnight. The commonest response was self-medication (39.84%), especially when dealing with pain and Pyrosis. Pyrazolones and Salicylates were the most commonly used drugs. The instructions were only read in 48.64% of cases. No measure was adopted in 34.56% of the disorders. The doctor was only consulted in 6.86% of cases. Both these responses were more common in men and young people. Non-pharmacological self-care was adopted in 30.07% of cases. This was generally of a dietetic or physical nature and was commoner in women and elderly people.

CONCLUSIONS

Self-care, whether pharmacological or not, is the most common response to the perception of some symptom. These practices (especially self-medication because of its possible attendant problems) should be directed and used as one tool more in health care.

Nicotinic and muscarinic receptors in the rat prefrontal cortex: differential roles in working memory, response selection and effortful processing

The aim of the present study was to evaluate the effects of cholinergic receptor blockade in the rat prefrontal cortex on cognitive processes. The nicotinic antagonists neuronal bungarotoxin and dihydro-beta-erythroidine and the muscarinic antagonist scopolamine were injected into the prelimbic area of the prefrontal cortex. Their behavioural effects were assessed in a T-maze to test reference memory (visual discrimination task) and working memory in delayed matching (MTS) and non-matching to sample (NMTS) tasks. Neuronal bungarotoxin produced a significant decrease in working memory performance in the MTS task but not in the NMTS task. In contrast, scopolamine impaired working memory in both MTS and NMTS tasks. Reference memory was not altered by any of the cholinergic antagonists. These results demonstrate a differential role of nicotinic and muscarinic receptors in the rat prefrontal cortex. Nicotinic transmission appears to be important in delayed response tasks requiring effortful processing for response selection, while the muscarinic system is involved in general working memory processes.

Narcolepsy associated with arteriovenous malformation of the diencephalon

Narcolepsy associated with localized brain lesions is rare, and few reports of well-documented cases have been published. We describe the case of a 20-year-old male (HLA DQw1 negative) who fulfilled clinical and polygraphic criteria of symptomatic narcolepsy. Narcolepsy in this patient was associated with an arteriovenous malformation involving the structures around the third ventricle. Clinical symptoms improved after embolization and radiosurgery. These findings support the hypothesis that lesions in the vicinity of the third ventricle can cause symptomatic narcolepsy.

Working memory, response selection, and effortful processing in rats with medial prefrontal lesions

This study examined the effects of lesions of the prelimbic area of the rat prefrontal cortex on acquisition and retention of nonmatching (NMTS) and matching-to-sample (MTS) tasks. Both tasks involved a reference and a working memory component, but only working memory was impaired by the lesions. A comparison of the 2 tasks revealed quantitatively similar deficits in postoperatively trained rats. In preoperatively trained rats, however, the deficits were more important in the MTS task than in the NMTS task. In addition, an effect of interference between successive trials was observed in the NMTS task but not in the MTS task. Perseverative tendencies were observed in the MTS task only. These results suggest that prefrontal lesions induce working memory deficits as a result of poor temporal encoding and increased susceptibility to interference and impair effortful processing, such as that engaged in response selection mechanisms.