Dose-related activity of stavudine in patients infected with human immunodeficiency virus

In a multicenter, randomized, open-label, dose-ranging study to determine the relative effects of three dose levels of stavudine on CD4 lymphocyte count, weight gain, and hematologic variables in patients infected with human immunodeficiency virus (HIV), 152 patients with CD4 lymphocyte counts < or = 600/mm3 received stavudine at 0.1 mg/kg/day (n = 51), 0.5 mg/kg/day (n = 53), or 2.0 mg/kg/day (n = 48). The study was designed to evaluate the activity of stavudine after 10 weeks of therapy and permitted extended dosing and follow-up for long-term safety. A significant dose effect on increases in CD4 lymphocyte counts and declines in HIV titer in peripheral blood mononuclear cells was observed. Stavudine was well-tolerated; the only dose-related, dose-limiting adverse event was peripheral neuropathy, which usually was reversible. In this trial, the most favorable therapeutic index was seen at 0.5 mg/kg/day.

Hantavirus infection: a rare disease which you should be aware

Hantavirus infection is caused by viruses classified in the Hantavirus genus, of the Bunyaviridae family. Recently a new hantavirus has been recognized. Specific endemic areas has been identified, however a new outbreak was identified in the southwestern of the United States. The principal vectors are rodents. Human infection occur by aerosol from rodent urine, saliva, feces and rodent bites. The infection classically is manifested clinically by fever, hemorrhage and renal failure. The recent outbreak was associated with acute respiratory illness without renal involvement. The treatment is with intravenous Ribavirin. Specific recommendations for prevention and control are presented here in.

[Infections of penile prosthesis: treatment and prevention]

To date, there are 10,000,000 men with impotence in the United States and it is estimated that at least 17,000 penile prosthesis are implanted annually. The most fearsome complication is the infection of the prosthesis which is usually caused by Staphylococcus epidermidis (in 40-80% of the cases). In general, the incidence of infection is actually 0.8-8.3%, but it can increase to 37% in patients with tertiary implants. The initial empiric treatment is usually with vancomycin and aminoglycosides and prophylaxis is recommended with a penicillinase-resistant synthetic penicillins, first generation cephalosporins, or vancomycin in case of penicillin allergy.

Cytomegalovirus retinitis in AIDS patients: a clinical review

Cytomegalovirus (CMV) retinitis is an ocular condition previously seen in organ transplant recipients, patient on chemotherapy for malignancy, and in infants with congenital infections. As it present in immunocompromised, the AIDS patient has integrated this group of patients that can present with CMV retinitis. Moreover, it is the leading cause of opportunistic ocular infection in the AIDS patient, and the second most common ocular manifestation. As new drugs and modes of administration are studied that can effectively halt this progressively blinding condition, the awareness and recognition of CMV retinitis on AIDS patients has become increasingly important. This author will review the epidemiology, clinical presentation, and differential diagnosis of this condition. The current treatments being used and complications will also be discussed.

[Pancreatic abscess and infected pseudocyst]

Acute pancreatitis is a sterile inflammatory process caused by a chemical auto digestion of the pancreas. The pancreatic abscess and infected pseudocyst are complications of acute pancreatitis of a high mortality rate that require a prompt diagnosis. The pseudocyst is defined as a localized collection of pancreatic juices confine to a retroperitoneal area by a fibrous membrane without epithelium; an abscess is a collection of pus and necrotic tissue. This illnesses should be suspected when patients with acute pancreatitis develop fever, tachycardia, abdominal distention or mass after 14-22 days after the initial attack. These entities require different treatment. The definite treatment is surgical intervention.

The new macrolides: expanding the ways in antibiotic treatment

After almost forty years of its introduction, erythromycin will not be the exclusive member of the macrolide group of antibiotic agents, but a new generation of its derivatives which surpass it in pharmacological properties and clinical efficacy will also be available. Clarithromycin, a 14-membered derivative, has shown acid stability, longer half-life, lower protein binding and higher lung tissue penetration. Its exceedingly high activity against erythromycin-susceptible gram-positive cocci, Mycoplasma pneumoniae, and Legionella pneumophila makes it and important alternative choice in the therapy of respiratory tract infections. Also, it has shown high activity against Chlamydia trachomatis, and high urinary clearance of this unmetabolized molecule, important properties which would render it a special role in the treatment of genitourinary tract infections. Azithromycin, a 15-membered derivative has shown enhanced basicity (due to the nitrogen atom in its lactone ring), longer half-life and lower protein bindings. Its exceptional activity against Hemophilus influenzae, Branhamella catarrhalis, Neisseria gonorrhoeae, Ureaplasma urealyticum and gram-negative bacteria, and its high concentration in tonsillar, pulmonary, prostatic and female reproductive tract tissues, assigns it an honorific place among the macrolides in the therapy against respiratory tract and genitourinary tract infections. Its role against T. gondii deserves further study, but points out this agent as a promise against this parasite.

CNS involvement in AIDS patients as seen with CT and MR: a review

The human immunodeficiency virus infected persons frequently have manifestations of central nervous system disfunction. These can be primary involvement or secondary processes such as infections or tumors. The present paper presents a short review of radiologic CNS findings in patients with AIDS as seen on CT and or MRI. The radiologic findings of HIV-1 encephalitis, toxoplasmosis, primary CNS lymphoma, PMLE, cryptococcosis, histoplasmosis, CMV encephalitis, HVS and varicella are presented. We expect this will ultimately help in the management of the AIDS patient.

Cytomegalovirus as nosocomial infection

Nosocomial infections with cytomegalovirus are an area of great concern and controversy within the medical community. With the advent of organ transplantation there have been an increased number of susceptible individuals. In the past most cases were confined to newborn nurseries and the neonatal intensive care unit. It is of great interest that recent evidence suggests that health care providers are at no greater risk of acquiring CMV infection inside the hospital setting when compared to a representative control group within the same community. This paper will review some of the literature that deals with the nosocomial transmission of CMV. We will try to emphasize transmission, diagnosis, prevention, and treatment of CMV infection.

Unusual presentation of Pseudomonas aeruginosa infections: a review

Pseudomonas aeruginosa is an opportunistic, gram negative bacillus that causes serious hospital acquired infections. However, it also causes infections with unusual presentations which are acquired in a non-hospital environment. This report will discuss the pathogenesis, clinical manifestations, and therapy of this uncommon infection, such as: 1) Pseudomonas folliculitis: a superficial or deep bacterial infection associated with the use of public hot tubs, whirlpools and swimming pools. 2) Invasive external otitis: an infection that can progress to skull base mostly associated to elderly diabetic patients. It is usually secondary to aural irrigation with contaminated water. 3) Pseudomonas osteomyelitis: an infection usually associated with nail puncture wounds especially if wearing tennis shoes. 4) Toe with infection: mostly associated with individuals using topical antibacterial agents. 5) Green nail syndrome: a non tender paronychia lesion that appears most often in persons whose hands are constantly exposed to water, soaps and detergents or are subject to mechanical trauma. 6) Corneal ulcer keratitis: mostly associated with the use of soft lenses, eye drops, mascara or contaminated whirlpools. This condition may terminate in panophthalmitis. 7) Endocarditis: most commonly associated with intravenous drug addicts.

Halophilic Vibrio infections: a review

Halophilic vibrios are gram-negative curved bacilli that requires high concentrations of salt for survival. They are usually found in marine environments and have a worldwide distribution. Infections caused by these organisms are usually associated with ingestion of raw shell fish or exposure of wounds to sea water. The clinical presentation and severity of this infections is wide ranging. The most common presentation is self-limiting gastroenteritis, but soft tissue infections and septicemia do occur and their morbidity and mortality is high specially in patients with liver disease. Early detection and initiation of treatment with tetracycline is of vital importance in soft tissue infections and septicemia since the progression of the infection may be extremely fast.

[Biology of the human immunodeficiency virus: a review]

The human immunodeficiency virus (HIV) a retrovirus responsible for the condition known as AIDS is presented from its biologic perspective. The viral structure and its relation to the pathogenesis of the infection is described. The course of the cellular infection is described and its relation to the manifestation of disease. The technology for detection of viral infection is described and the importance of seropositivity. The manifestations are described in relation to the virus as well as the possible intervention. There is still no alternative but education.

[Parvovirus infections in humans]

The Human Parvovirus (HPV) like other Parvovirus is a single strand DNA virus with autonomous replication which measures 23mm. Infection with this virus is followed by a non-specific viral syndrome during the prodrome, leading to viremia, which may be followed by arthropathy and/or different kind of rash including the syndrome called erythema infectiosum. It has also been related to an increase in the number of spontaneous abortion in pregnant women with acute infection; and it is the etiology of the aplastic crisis in patients with hemolytic anemias. Many other Parvovirus serologically different from HPV are present in stools and are responsible for acute infectious non bacterial gastroenteritis in people more than 5 years old.

Susceptibility of aerobic gram-negative bacilli to aminoglycosides. Effects of 45 months of amikacin as first-line aminoglycoside therapy

Amikacin was instituted as the primary empiric aminoglycoside at the San Juan Veterans Administration Medical Center in January 1982; at that time, 16 percent of the strains at the hospital were gentamicin-resistant. A prospective surveillance study was designed to correlate detection of bacterial resistance with aminoglycoside use. In the current report, the baseline period, during which gentamicin was the first-line aminoglycoside, accounting for 61 percent of overall aminoglycoside use, is compared with the period from January 1982 to September 1985, during which the first-line aminoglycoside was amikacin, accounting for 85 percent of overall use. This study is ongoing. During the two periods, the patient population did not differ with regard to aminoglycoside therapy, indications, or overall aminoglycoside use (541 versus 680 patient days per month). Among the gram-negative bacilli isolated, the percent of strains resistant to amikacin was as follows: pre-baseline period/baseline period, 0.8/0.2 percent; amikacin-usage period, 3.6 percent. Resistance to gentamicin and tobramycin during the period of amikacin use decreased from 16 to 11 percent for gentamicin and from 17 to 11 percent for tobramycin. The decrease in resistance of the gram-negative bacilli to gentamicin varied among strains: the resistance of Escherichia coli decreased from 8 to 4 percent; that of Proteus mirabilis, from 12 to 5 percent; that of indole-positive Proteus, from 19 to 12 percent; that of Acinetobacter, from 57 to 23 percent; that of Citrobacter, from 15 to 7 percent; and that of Pseudomonas aeruginosa, from 24 to 16 percent. During the amikacin-usage period, amikacin resistance was unchanged for most strains, with the exception of P. aeruginosa, the resistance of which increased from 4.5 to 7.8 percent. Of the 4,795 strains isolated, 174 were resistant to amikacin; of these, 29 Pseudomonas strains were studied for all mechanisms of resistance. Changes in permeability were exhibited by 11 of the 29 strains; 14 strains exhibited the AAC(6')-I enzyme, 10 strains exhibited the APH(3')-II enzyme, and two strains exhibited ANT(2") in addition to some other unidentified mechanism. Multiple enzyme production was found in 15 of the strains. The use of amikacin as a first-line aminoglycoside is associated with a decrease in resistance to other aminoglycosides and a slight increase in overall resistance to amikacin among aerobic gram-negative bacilli. The usefulness of amikacin has not been affected at our institution.

Dengue and hepatic failure

Dengue hemorrhagic fever/dengue shock syndrome is a serious manifestation of dengue fever, which is observed predominantly in the tropical regions of the West Pacific and in Southeast Asia and is associated with secondary infections, mainly in children under age 15. A concomitant microangiopathic coagulopathy has been described; moreover, encephalopathy and even Reye's syndrome have been rarely reported. This report describes a 51-year-old man with secondary dengue infection who presented with clinical evidence of severe hepatitis, encephalopathy, cranial nerve palsy, and microangiopathic coagulopathy and who had a favorable outcome. A careful surveillance for the occurrence of secondary dengue in the Western Hemisphere is proposed, and dengue is suggested as a diagnostic possibility in obscure febrile illnesses presenting as either hepatitis, encephalopathy, or coagulopathy in places in which the mosquito vector, Aedes aegypti, is present.

Efficacy and safety of aztreonam-clindamycin versus tobramycin-clindamycin in the treatment of lower respiratory tract infections caused by aerobic gram-negative bacilli

A total of 80 patients were randomized to receive either aztreonam or tobramycin for the treatment of lower respiratory tract infections caused by gram-negative bacilli; all these patients received clindamycin concomitantly. A total of 53 patients were randomized to receive aztreonam-clindamycin; of these, 46 were clinically evaluable and 39 were bacteriologically evaluable. Of the 46 clinically evaluable patients, 41 were considered cured, 3 failed to be cured, and 2 died during the study period of unrelated causes. Of the 39 bacteriologically evaluable patients, 36 were considered cured, and 3 failed to be cured. There were 26 clinically evaluable patients in the group randomized to receive tobramycin-clindamycin. Of them, 22 patients were considered cured, 3 failed to be cured, and 1 died of unrelated causes during the study period. There were 18 bacteriologically evaluable patients in the tobramycin-clindamycin group; 17 were cured, and 1 failed to be cured. The most common pathogens isolated from the patients were Klebsiella pneumoniae, Escherichia coli, and Pseudomonas aeruginosa. All of the isolated organisms were susceptible to both tested antibiotics, except for a strain of Pseudomonas cepacia resistant to both tested antimicrobial agents and a strain of Enterobacter aerogenes and one of P. aeruginosa that were resistant to aztreonam. Very few adverse reactions related to the antibiotics were seen. These effects, when present, were transient and comparable in both studied groups, except for renal-function tests, which were altered in 7.7% of the patients randomized to receive tobramycin-clindamycin and in none of the patients randomized to receive aztreonam-clindamycin. Aztreonam-clindamycin is safe and effective for the treatment of lower respiratory tract infections caused by aerobic gram-negative bacilli when the organisms are susceptible.

In vitro susceptibility of 50 non-beta-lactamase-producing Neisseria gonorrhoeae strains to 12 antimicrobial agents

The in vitro activities of six commonly used antibiotics and six newer beta-lactam agents were determined in 50 consecutive clinical isolates of beta-lactamase-negative Neisseria gonorrhoeae. The gonococci isolated were notably resistant to penicillin, ampicillin, erythromycin, and tetracycline, whereas all of the strains were susceptible to the newer beta-lactam agents cefoxitin and spectinomycin.

Cefamandole in the treatment of soft tissue infections

27 male adult patients with acute soft tissue infections including cellulitis, abscesses, ulcers and wound infections were treated with a dose of 2-4 g/day of cefamandole nafate by the intravenous route for a minimum of 10 days. Most patients were seriously ill with underlying conditions like diabetes mellitus, alcoholism and congestive heart failure and required hospitalization and parenteral antibiotics. Gram-positive cocci (predominantly Staphylococcus aureus) and gram-negative bacilli were recovered on pretreatment cultures from 81% of the patients. Clinical and bacteriologic response was excellent. Disappearance of the signs of infection occurred by the 7th day of treatment, by day 3 of treatment fever was down to normal, and by day 5 of treatment the WBC count was below 8,000. There were very few side effects noted, and there was excellent tolerance to the intravenous drug administration. Cefamandole nafate is a safe, effective and well-tolerated agent in the treatment of skin and soft tissue infections of adult patients caused by susceptible organisms.

Amikacin sulfate levels in human serum and bile

Amikacin levels in blood and bile were measured in 10 patients who underwent cholecystectomy and T-tube drainage. Each patient received 500 mg of amikacin intravenously 12 h preoperatively, during surgery, and every 12 h thereafter for four more doses. Average levels of amikacin in bile were 8.3 micrograms/ml at 1 h after the intraoperative dose, with a bile/serum ratio of 0.44. Postoperative doses at 1 h produced levels in bile of 3.8 to 4.2 micrograms/ml, with a bile/serum ratio of 0.15 to 0.22. Levels in bile decreased at a rate lower than levels in blood, and bile/serum ratios increased from 0.54 at 2 h to 0.93 at 12 h. Amikacin accumulated in bile at 6 h after the intravenous dose.

Pharyngeal flora in ambulatory alcoholic patients: prevalence of gram-negative bacilli

The pharyngeal flora of a group of ambulatory alcoholic patients was studied and compared with the pharyngeal flora of a control group. Sixty-eight patients were studied, 34 alcoholics and 28 controls. Of the alcoholic patients, 59% had Gram-negative bacilli in their pharyngeal flora, while 14% of the control group had the same organisms. There were no differences in Gram-positive cocci colonization between the groups. Klebsiella pneumoniae was the most frequent isolate (40%) and the Klebsiella-Enterobacter group accounted for 76% of the isolates. Colonization rates of greater than 10 colony forming units/ml were found in 43% of the alcoholic patients. The high prevalence and higher colonization rates of Gram-negative bacilli in alcoholic patients might explain the higher incidence of Gram-negative bacillary pneumonia among alcoholics.