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Biomedical subjects

H F Gomez

Publications and source records attributed to H F Gomez.

26 records · Page 2Linked to original sources
PubMed1994

Human envenomation from a wandering garter snake.

Garter snake bites are generally innocuous to human beings. We report a case of human envenomation from the Wandering Garter snake (Thamnophis elegans vagrans). The patient, who was bitten on his right third fingertip, rapidly developed local edema, ecchymosis, and hemorrhagic vesicles. Systemic signs and symptoms did not develop. The clinical picture was similar to that in three previous patients with Thamnophis envenomation in that clinical signs followed a prolonged bite. Thamnophis species have Duvernoy's glands, which may be analogous to venom glands in Crotalidae (pit viper) species. The progressive local effects produced by secretions of these glands may be confused with early Crotalidae envenomation.

Adolescent↗
PubMed1992

Concentration of milk secretory immunoglobulin A against Shigella virulence plasmid-associated antigens as a predictor of symptom status in Shigella-infected breast-fed infants.

We conducted a prospective, community-based study of healthy breast-fed Mexican infants to determine the protective effects of anti-Shigella secretory IgA antibodies in milk. Milk samples were collected monthly, and stool culture specimens were obtained weekly and at the time of episodes of diarrhea. Nineteen breast-fed infants were found to have Shigella flexneri, Shigella boydii, or Shigella sonnei in stool samples. Ages of the 10 infants with symptomatic infection and the nine with asymptomatic infection did not differ significantly. Milk samples collected up to 12 weeks before infection were evaluated by enzyme-linked immunosorbent assay for secretory IgA antibodies against lipopolysaccharides of S. flexneri, S. boydii serotype 2, S. sonnei, and virulence plasmid-associated antigens. The geometric mean titers of anti-Shigella antibodies to virulence plasmid-associated antigens in milk received before infection were eightfold higher in infants who remained well than in those in whom diarrhea developed. The significance of milk secretory IgA directed against lipopolysaccharide was less clear. We conclude that human milk protects infants against symptomatic shigella infection when it contains high concentrations of secretory IgA against virulence plasmid-associated antigens.

Antigens, Bacterial↗
PubMed1992

Polymerase chain reaction for diagnosis of enterohemorrhagic Escherichia coli infection and hemolytic-uremic syndrome.

Two pairs of oligonucleotide primers were designed to amplify fragments of the genes for Shiga-like toxin I (SLT-I) and SLT-II in a single reaction. A 370-bp segment and a 283-bp segment were amplified for SLT-I and SLT-II, respectively. The specificities of the polymerase chain reaction (PCR) amplification products were confirmed by using radioactively labeled oligonucleotide probes. SLT sequences were amplified from DNA isolated from 13 previously characterized enterohemorrhagic Escherichia coli (EHEC) strains. No amplification product was produced by using DNA from 20 non-EHEC strains. As little as one bacterial genome was detectable. PCR was then applied to DNA isolated directly from stool samples. We had to remove inhibitors of PCR that were present in lysates prepared from stool samples before amplification was achieved. First, we evaluated the sensitivity of PCR for the detection of known numbers of EHEC added to normal stools. Second, three children with SLT in their stools were shown to have SLT sequences in their stools by PCR. Two of these children had hemolytic-uremic syndrome, and a third child was asymptomatic. Stool specimens collected from another 26 asymptomatic children were negative by PCR for SLT sequences. PCR can be used to diagnose EHEC infections without prior culture of stool specimens.

Bacterial Toxins↗
PubMed1991

Evidence for long-term memory of the mucosal immune system: milk secretory immunoglobulin A against Shigella lipopolysaccharides.

Although the common mucosal immune system has generally been considered to have only short-term memory, recent data suggest that long-term memory exists for Shigella virulence plasmid antigens. Because such antigens might cross-react with environmental antigens, we investigated milk for the persistence of antibodies to the specific Shigella lipopolysaccharide (LPS) antigens. Enzyme-linked immunosorbent assays to detect secretory immunoglobulin A (sIgA) against Shigella flexneri and Shigella sonnei LPS in milk samples were developed; 15 random milk samples tested on different days correlated from one day to the next (P = 0.0001). Of 18 Mexican mothers, 18 (100%) had one or more milk samples positive for anti-S. flexneri LPS, 14 (78%) had one or more milk samples positive for anti-S. sonnei LPS, and 14 (78%) had one or more milk samples positive for both. Of 27 Houston mothers, 16 (59%) had one or more milk samples positive for anti-S. flexneri LPS, 7 (26%) had one or more milk samples positive for anti-S. sonnei LPS, and 5 (19%) had one or more milk samples positive for both. Mexican mothers were significantly more likely than Houston mothers to have at least one sample with a positive titer for anti-S. flexneri LPS (P less than 0.02) and at least one sample with a positive titer for anti-S. sonnei LPS (P less than 0.002). Although the Houston women had a lower rate of titer positivity for both Shigella species, the rate was too high to be consistent with short-lived mucosal immunity. It is unlikely that 18 of the 27 Houston women had shigellosis during or just prior to lactation. The data suggest that there exists a long-term hormonally driven memory in the secretory immune system for Shigella spp.

Antibodies, Bacterial↗
PubMedDate not supplied

Charcoal stercolith with intestinal perforation in a patient treated for amitriptyline ingestion.

A case of a patient who developed an intestinal perforation secondary to a charcoal stercolith is reviewed. The case involves a young female on methadone maintenance who received multiple-dose charcoal therapy for an amitriptyline ingestion. Peritoneal signs developed several days after admission, and an exploratory laparotomy was done. A perforation measuring 4 cm in diameter was found in the posterior wall of the sigmoid colon. A 120-gm obstructing charcoal mass was found at the site of the perforation. Previous reports of intestinal obstruction secondary to charcoal inspissation are noted, and case similarities are discussed. All reported cases of charcoal obstruction involve the administration of multiple-dose-activated charcoal in the treatment of ingestions of medications known to have antiperistaltic activity. With a rare potential of mechanical obstruction, the decision to use repetitive-dose charcoal therapy should be made judiciously when the ingested toxin or coincident therapeutic medications have antiperistaltic activity.

Adult↗