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Biomedical subjects

C H Ramírez-Ronda

Publications and source records attributed to C H Ramírez-Ronda.

At least 19 recordsLinked to original sources

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.

Anti-Bacterial Agents

Disseminated histoplasmosis.

We have presented the microbiology, pathogenesis, clinical presentation, diagnosis and treatment of disseminated histoplasmosis. Emphasis is presented on the manifestations in the HIV infected patient.

Histoplasmosis

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.

Cross Infection

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.

Acquired Immunodeficiency Syndrome

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.

Humans

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.

Corneal Ulcer

[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.

Acquired Immunodeficiency Syndrome

[The use of ciprofloxacin in patients with osteomyelitis associated with vascular insufficiency].

Osteomyelitis in patients with peripheral vascular insufficiency (PVI) has several characteristics which make its management a very difficult and controversial one. Generally it requires a prolonged course with broad spectrum intravenous antibiotics, which in turn requires hospitalization, increased risk of side effects and elevated cost. During the last years, the investigators developed the fluoroquinolones, which may help to simplify this treatment. These agents inhibit the synthesis of bacterial deoxyribonucleic acid. Ciprofloxacin is one of the most active of them. It has the following characteristics: broad spectrum of action, rapid absorption when administered by oral route, tolerated well by the patient, may be administered only twice a day, reach therapeutic concentrations in bone and it was more effective when compared with other antibiotics under the same conditions. Although the development of resistance against it has been clinically significant, it has been reported. We, the physicians, have the responsibility to use the quinolones correctly to avoid the development of resistance. Actually, ciprofloxacin is indicated for the treatment of osteomyelitis in patients with PVI, if it is bacteriologically documented. It is not indicated for empirical use. We use 750mg every 12 hours during 3 to 6 months. We have not been presenting ciprofloxacin as a panacea, but as an effective alternative, with clear indications that can decreases the cost of the treatment of osteomyelitis associated with PVI.

Anti-Infective Agents

[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.

Female

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.

Acetyltransferases

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.

Cranial Nerve Diseases

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.

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