Fatal dengue hemorrhagic fever in Cuba, 1997

OBJECTIVES

After more than 15 years without dengue activity, a dengue II epidemic was reported in Cuba in 1997. Three thousand and twelve serologically confirmed cases were reported, with 205 dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) cases and 12 fatalities. This report presents the clinical, serologic, and virologic findings in the 12 fatal DHF/DSS cases.

METHODS

Serum and necropsy samples were studied by viral isolation in C636 cell line and polymerase chain reaction. Serum samples were tested by IgM capture enzyme-linked immunoassay (ELISA) and ELISA inhibition method (EIM).

RESULTS

All 12 cases were classified as DHF/DSS according to the Pan American Health Organization Guidelines for Control and Prevention of Dengue and Dengue Hemorrhagic Fever in the Americas. All patients were older than 15 years. Women were more frequently affected. The symptoms and signs presented by these patients were similar to those previously described in DHF/DSS cases. Clinical deterioration occurred on average at day 3.75. Abdominal pain and persistent vomiting were the earliest and most frequent warning signs. Dengue infection was confirmed in all cases. IgM antibodies were detected in 11 of 12 cases, all of them with a secondary infection. Dengue II virus was detected by viral isolation in 12 samples and by polymerase chain reaction in 17. Virus or RNA was detected in various tissues, including kidney, heart, lung, and brain.

CONCLUSION

The clinical, pathologic, and laboratory features of 12 cases of fatal dengue hemorrhagic fever were reviewed. The results obtained demonstrate that adults with a primary dengue infection are at risk of developing the severe disease (DHF) if they are infected with a different serotype.

Biliary tract infection caused by Haemophilus parainfluenzae

Haemophilus parainfluenzae was isolated from the bile specimens of 2 patients with acute cholecystitis. The strains were genetically unrelated by the random amplified polymorphic DNA (RAPD). The 2 H. parainfluenzae strains represented 11.7% of all positive bile cultures inoculated in blood culture bottles. The routine inoculation of bile specimens in media able to support growth of Haemophilus species should be considered.

Lys13 plays a crucial role in the functional adaptation of the thermophilic triose-phosphate isomerase from Bacillus stearothermophilus to high temperatures

The thermophilic triose-phosphate isomerases (TIMs) of Bacillus stearothermophilus (bTIM) and Thermotoga maritima (tTIM) have been found to possess a His12-Lys13 pair instead of the Asn12-Gly13 pair normally present in mesophilic TIMs. His12 in bTIM was proposed to prevent deamidation at high temperature, while the precise role of Lys13 is unknown. To investigate the role of the His12 and Lys13 pair in the enzyme's thermoadaptation, we reintroduced the "mesophilic residues" Asn and Gly into both thermophilic TIMs. Neither double mutant displayed diminished structural stability, but the bTIM double mutant showed drastically reduced catalytic activity. No similar behavior was observed with the tTIM double mutant, suggesting that the presence of the His12 and Lys13 cannot be systematically correlated to thermoadaptation in TIMs. We determined the crystal structure of the bTIM double mutant complexed with 2-phosphoglycolate to 2.4-A resolution. A molecular dynamics simulation showed that upon substitution of Lys13 to Gly an increase of the flexibility of loop 1 is observed, causing an incorrect orientation of the catalytic Lys10. This suggests that Lys13 in bTIM plays a crucial role in the functional adaptation of this enzyme to high temperature. Analysis of bTIM single mutants supports this assumption.

The effect of arginine or glycine supplementation on gastrointestinal function, muscle injury, serum amino acid concentrations and performance during a marathon run

Gastrointestinal bleeding and increased intestinal permeability have been observed in marathon runners. We sought to determine if L-arginine would be useful for prevention of these complications. Twenty-three runners were randomized to receive L-arginine (A) or glycine (placebo) (G), 10 grams 3 times daily for 14 days prior to the 1997 Houston-Methodist Marathon. Serum, stool hemoccults and lactulose:mannitol permeabilities were obtained at baseline, immediately after completion of the marathon and approximately 48 hours later. Runners rated their symptoms of nausea and vomiting, belching and indigestion, abdominal pain and bloating, diarrhea, and extremity pain on a 1-5 scale of increasing severity. The L:M was unchanged in either group during the three collections. Occult bleeding occurred in 8%/20% in A and G groups, respectively, p = NS) immediately post-marathon. No runners had occult bleeding 48 hours post-race. Gastrointestinal symptom scores were minimal to nonexistent. Extremity pain scores were similar for groups A and G (2.1+/-1.4 and 2.8+/-1.6, respectively, (p = NS). Fluid intake was similar between both groups (1875+/-1547 vs. 1506+/-970 ml, p = NS). Serum amylase was normal at baseline and remained virtually unchanged. Serum lipase was normal at baseline and immediately post-race in both groups, but increased at 48 hours post-race (82.2+/-34.3 to 121.5+/-53.3 mg/dl [A], p = 0.02 and 114.3+/-55.7 to 181.9+/-162.2 mg/dl [G], p = 0.09). CPK increased significantly and similarly in both groups immediately post-race, and even more dramatically 48 hours post-race (130.3+/-130.8 to 738.8+/-902.9, p = 0.007 to 1966.5+/-3.166.0 mg/dl [A] and 140.9+/-77.9 to 863.0+/-772.3, p = 0.003 to 5619+/-10636.8mg/dl [G]). Modest post-race decreases were seen in most serum amino acids in both groups. Finish times were longer than predicted (23+/-21 and 9+/-7 min for A and G groups, respectively, p = 0.049). Our study failed to show a clear benefit of arginine supplementation for the prevention of intestinal ischemia/reperfusion injury associated with endurance running, but either a detrimental affect on performance with arginine, or enhanced performance with glycine. Skeletal muscle injury was unaffected by arginine or glycine supplementation. The delayed increase in serum lipase suggests mild pancreatic injury, affected by either arginine or glycine supplementation.

A controlled study of transesophageal echocardiography to guide central venous catheter placement in congenital heart surgery patients

Transesophageal echocardiography (TEE) and central venous catheter (CVC) placement are often used during congenital cardiac surgery. Complications of CVC placement include cardiac perforation, inadvertent arterial placement, and erroneous hemodynamic data from unrecognized malposition. In this study, we used a prospective, randomized, controlled design to evaluate the use of TEE to guide depth of insertion and confirm superior vena cava cannulation, and to improve the percentage of correctly placed CVCs and reduce complications of CVC placement. One hundred forty-five patients were studied. Eighty patients were randomized to have subclavian vein insertion, 64 to have internal jugular insertion, and 1 to have external jugular insertion of CVC. TEE-guided CVC placement resulted in 100% correct placement when assessed by preoperative TEE, versus 86% in the control group (72 of 72 vs. 63 of 73; P = 0.01). There was no difference in correct placement between the two groups when assessed by postoperative chest radiograph (81.9% TEE versus 75.3% control; P = not significant). One significant complication, a superior vena cava perforation, occurred in the control group. Time to placement was 9.6 min in the TEE group versus 8.0 min in the control group (P = 0.015).

IMPLICATIONS

Transesophageal echocardiography can be used to guide central venous catheter placement in congenital heart surgery. Central venous catheters that seem to be located high in the right atrium by chest radiograph in these patients are often actually in the superior vena cava and pose little risk of cardiac perforation.

Acute pancreatitis: evaluation of the prognostic criteria of the latest Balthazar tomographic classification

The use of prognostic criteria to detect potentially acute pancreatitis can allow us to select patients most in need of special attention. Of the many possible criteria, we used Ranson's clinical analytic criteria and Balthazar's tomographic criteria, and compared them to the latest criteria of Balthazar, in which pancreatic necrosis figures as the principal prognostic factor. Tomographic evaluation of pancreatic necrosis was shown to be the best prognostic marker in acute pancreatitis, with the greatest sensitivity and specificity of all methods used with one-hundred consecutive patients admitted with acute pancreatitis.

Repetitive strain injury (cumulative trauma disorder): causes and treatment

BACKGROUND

The computerization of the workforce in the last two decades has led to increases in the incidence of repetitive strain injury (RSI). U.S. Workers Compensation claims made by persons disabled in the upper extremities in 1989 were estimated to be $563 million.

METHOD

Through an investigation of factors that increase the likelihood of contracting an RSI in various industries, the authors suggest a relation between workplace conditions, lack of education about causes of RSI and improper use of equipment among contemporary workers.

RESULTS

A medical term which analyzes the unique history and mechanism of the injury and offers a unique regimen of exercise, education, modalities and some pain management has proven to be the most effective treatment for RSI. Damage to muscle and tendon due to RSI generally cannot be surgically repaired. However, specific nerve-related disorders can be treated with surgery if other more conservative treatments prove ineffective.

CONCLUSION

Through foresight and education, industries in which specific factors render workers more likely to contract RSI can begin to take steps to minimize worker susceptibility to the disorder. Those industries will face large losses due to Workers' Compensation claims, disability pay, lawsuits and ultimately lower productivity.

[Neuro-cognitive condition of 8 year old children with congenital hypothyroidism treated early]

INTRODUCTION

Congenital hypothyroidism is the most important cause of preventable mental retardation. Since the use of programmes for early detection, mental retardation due to cretinism has been abolished and current investigations seek to detect subtle damage due to foetal hypothyroidism and strategies to minimize such deficits.

OBJECTIVE

This study presents the results of neurocognitive assessment of a group of 19 children aged 8 in the Cuban Programme for the early detection of Congenital Hypothyroidism.

PATIENTS AND METHODS

The programme is based on the use of umbilical cord serum levels of thyrotropin (TSH), using the Elisa ultramicro method (SUMA) and substitutive treatment with sodium levothyroxine and a programme of neuropsychiatric stimulation until 5 years old.

RESULTS

The results showed that the intelligence quotients of children with hypothyroidism were not statistically different from paired controls, and thus demonstrate the efficacy of the programme. On evaluation using computerized techniques for the detection of subtle disorders of the maintenance of attention, deficiencies were found. Analysis of the conventional EEG showed that in 13 cases recordings were normal, 4 had generalized cortical damage, 1 had cortico-subcortical damage and the remainder had signs of focal irritation. On the quantitative EEG, correlation between the attention variables and absolute values (MV2/Hz) were calculated for each derivation and associations found mainly in the right parietal and left frontal regions.

CONCLUSION

The effect of stimulating development in these patients is discussed.

Class I chitinases as potential panallergens involved in the latex-fruit syndrome

BACKGROUND

Latex-fruit cross-sensitization has been fully demonstrated. However, the antigens responsible for this "latex-fruit syndrome" have not been identified. We have recently shown that class I chitinases are relevant chestnut and avocado allergens.

OBJECTIVE

We sought to evaluate the in vivo and in vitro reactions of purified chestnut and avocado chitinases in relation to the latex-fruit syndrome.

METHODS

From a latex-allergic population, eighteen patients allergic to chestnut, avocado, or both were selected. Skin prick tests (SPTs) were performed with crude chestnut and avocado extracts, chitinase-enriched preparations, and purified class I and II chitinases from both fruits. CAP-inhibition assays with the crude extracts and purified proteins were carried out. Immunodetection with sera from patients with latex-fruit allergy and immunoblot inhibition tests with a latex extract were also performed. Eighteen subjects paired with our patients and 15 patients allergic to latex but not food were used as control groups.

RESULTS

The chestnut class I chitinase elicited positive SPT responses in 13 of 18 patients with latex-fruit allergy (72%), and the avocado class I chitinase elicited positive responses in 12 of 18 (67%) similarly allergic patients. By contrast, class II enzymes without a hevein-like domain did not show SPT responses in the same patient group. Each isolated class I chitinase reached inhibition values higher than 85% in CAP inhibition assays against the corresponding food extract in solid phase. Immunodetection of the crude extracts and the purified class I chitinases revealed a single 32-kd band for both chestnut and avocado. Preincubation with a natural latex extract fully inhibited the IgE binding to the crude extracts, as well as to the purified chestnut and avocado class I chitinases.

CONCLUSION

Chestnut and avocado class I chitinases with an N-terminal hevein-like domain are major allergens that cross-react with latex. Therefore they are probably the panallergens responsible for the latex-fruit syndrome.

[The tilt-table test in assessing syncope of unknown origin: do differences exist between children and adults?]

BACKGROUND AND OBJECTIVES

Little is known about the differences between children and adults in the results of head-up tilt test. This study sought to investigate the potential differences concerning: a) the clinical profile and circumstances of spontaneous syncope; b) the overall diagnostic performance of the test, and c) the type of positive response obtained.

MATERIAL AND METHODS

We studied 31 children and 123 adults with unexplained syncope. If baseline test (tilting at 70 degrees for 30 min) resulted negative, it was repeated under isoprenaline low-dose infusion.

RESULTS

There were no differences in either clinical profile, except for severe traumatism more frequent in adults (25% vs. 3% in children; p < 0.05), or overall diagnostic performance (39% in children vs. 33% in adults; p = NS). However, the way the test rendered positive (via basal tilting in 92% of children vs. 50% in adults; p < 0.05) and the rate of cardioinhibitory response (42% in children vs 8% in adults; p < 0.01) were significantly different.

CONCLUSIONS

In this study children, in contrast to adults, rarely have a positive response in tilting under isoprenaline infusion. They also present a much higher rate of cardio-inhibitory response than adults.

Use of methylene blue in patients with refractory septic shock: impact on hemodynamics and gas exchange

PURPOSE

The purpose of this study was to assess the acute effects of methylene blue, an inhibitor of nitric oxide synthesis, on hemodynamics and gas exchange in patients with refractory septic shock in a prospective clinical trial at medical and surgical intensive care units in a tertiary university hospital.

PATIENTS AND METHODS

Prospective, sequential study of 10 consecutive patients admitted with severe septic shock of diverse causes and unable to achieve an adequate arterial pressure despite the use of at least two vasoactive drugs. Six of them also developed acute lung injury. All received 1 mg/kg intravenous bolus of methylene blue. Hemodynamic and respiratory parameters were measured at baseline and at 30, 60, 120, and 180 minutes after the bolus injection.

RESULTS

Systolic, diastolic, mean arterial blood pressure, and systemic vascular resistance increased significantly in all patients, whereas no significant changes were observed in cardiac output, oxygen consumption, or oxygen extraction ratio. Gas exchange remained unaffected in patients with acute lung injury.

CONCLUSIONS

Methylene blue had an acute vasopressor effect in patients with refractory septic shock, and it was not deleterious on respiratory function.

[Chlamydia pneumoniae in patients with acquired pneumonia in the Santiago of Chile community]

BACKGROUND

The prevalence of Chlamydia pneumoniae infection varies according to the population and geographic area studied.

AIM

To evaluate the incidence of Chlamydia pneumoniae infection in Chilean subjects with community acquired pneumonia.

PATIENTS AND METHODS

Between 1995 and 1997, patients with community acquired pneumonia attending two emergency rooms in Santiago, were studied. The diagnosis of Chlamydia pneumoniae infection was based on the detection of Chlamydia pneumoniae specific IgG antibody in samples from both the acute and convalescent phase, using an indirect microimmunofluorescent technique. Evidence of present infection was defined as seroconversion, a significant increase in the titer of the second sample and an initial titer equal or greater than 1/512.

RESULTS

During the study period, 160 patients consulted and seven (six male), aged 54 +/- 27 years old, complied with the diagnostic criteria of present Chlamydia pneumoniae infection. These patients had no special clinical or radiological features. Five of seven patients improved without any specific treatment.

CONCLUSIONS

Eight percent of this sample of patients with community acquired pneumonia had Chlamydia pneumoniae infection. This agent should be included in the design of empiric treatment schemes, although our results cast doubt on the pathogenic role of Chlamydia pneumoniae in pneumonia.

[The physicochemical characterization of the strains isolated during the outbreak of epidemic neuropathy in Cuba. II]

The presence of 2 agents such as a Cox A9 strain and another mild cytopathogenic effect-producing strain, both isolated from patients presenting with epidemic neuropathy is reported in this paper. A mild cutopathogenic effect which was propagated in successive dilutions was developed in the dilution 10(-4) by means of the neutralization test of a Coxsackie A9 virus with its homologous hyperimmune serum. A gradient in saccharose was performed in a mild cytopathogenic effect-producing strain and a typical cytopathogenic effect of an Enterovirus developed from one of the fractions passed in tissular cultures in the presence phosphonoacetic acid (PAA). The possible pathogenic role of these viruses are discussed.

[Cuban epidemic neuropathy. IV. The antigenic relationship of the viral isolates to the structures of the central nervous system. A possible etiopathogenic mechanism?]

Results which allow to state the existence of antigenic relationships between viruses isolated from the cerebrospinal fluid of patients presenting with epidemic neuropathy and structures of the human central nervous system are reported. These evidences were obtained by 2 different and independent ways: 1) by the double diffusion method in agarose, immunoblot analysis, and immunohistochemical analysis it was confirmed that antibodies induced by isolated viruses react with antigens of the central and peripheral nervous system, 2) serum obtained by the immunization of a rabbit with human brain extract neutralizes the same viruses as those neutralized by hyperimmune sera obtained by isolations. The possible role of viruses as mediators of an autoimmune process in the pathogenesis of the disease is discussed.

[The factors affecting the growth of the agent, producing a mild cytopathic effect, isolated in patients with epidemic neuropathy]

Certain factors influencing upon the growth of the agent producer of mild cytopathogenic effect and isolated from the cerebrospinal fluid of patients presenting with epidemic neuropathy are described in this paper. It was demonstrated that a concentration of NaHCO3 was essential for the occurrence of the cytopathogenic effect. Determined concentrations of MnCl2 allowed for the visualization of the cytopathogenic effect and increased viral yields.