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Biomedical subjects

R H Gilman

Publications and source records attributed to R H Gilman.

At least 19 recordsLinked to original sources
PubMed2006

Treatment of neurocysticercosis: current status and future research needs.

Here we put forward a roadmap that summarizes important questions that need to be answered to determine more effective and safer treatments. A key concept in management of neurocysticercosis is the understanding that infection and disease due to neurocysticercosis are variable and thus different clinical approaches and treatments are required. Despite recent advances, treatments remain either suboptimal or based on poorly controlled or anecdotal experience. A better understanding of basic pathophysiologic mechanisms including parasite survival and evolution, nature of the inflammatory response, and the genesis of seizures, epilepsy, and mechanisms of anthelmintic action should lead to improved therapies.

Anticonvulsants↗
PubMed2006

Analysis of nucleotide diversity of NAT2 coding region reveals homogeneity across Native American populations and high intra-population diversity.

N-acetyltransferase 2 (NAT2), an important enzyme in clinical pharmacology, metabolizes antibiotics such as isoniazid and sulfamethoxazole, and catalyzes the transformation of aromatic and heterocyclic amines from the environment and diet into carcinogenic intermediates. Polymorphisms in NAT2 account for variability in the acetylator phenotype and the pharmacokinetics of metabolized drugs. Native Americans, settled in rural areas and large cities of Latin America, are under-represented in pharmacogenetics studies; therefore, we sequenced the coding region of NAT2 in 456 chromosomes from 13 populations from the Americas, and two from Siberia, detecting nine substitutions and 11 haplotypes. Variants *4 (37%), *5B (23%) and *7B (24%) showed high frequencies. Average frequencies of fast, intermediate and slow acetylators across Native Americans were 18, 56 and 25%, respectively. NAT2 intra-population genetic diversity for Native Americans is higher than East Asians and similar to the rest of the world, and NAT2 variants are homogeneously distributed across native populations of the continent.

Acetylation↗
PubMed2006

Use of a reliable PCR assay for the detection of Neisseria gonorrhoeae in Peruvian patients.

Neisseria gonorrhoeae is the most common sexually transmitted disease-causing bacterium worldwide. An in-house PCR assay targeting the carbamoyl-phosphate synthase subunit A (carA) gene was developed for the specific detection of N. gonorrhoeae in clinical specimens. Samples from 605 patients were cultured on selective medium and assayed by PCR in a double-blind fashion. Of 605 urethral/cervical samples analysed, 13 were PCR-positive, of which 11 were culture-positive. The PCR showed a sensitivity and specificity of 100% and 99.7% with these samples. PCR targeting the carA gene appears to be a reliable method for the detection of N. gonorrhoeae in clinical specimens.

Female↗
PubMed2006

Combined human and porcine mass chemotherapy for the control of T. solium.

A combined (human and porcine) mass chemotherapy program was tested in a controlled design in 12 village hamlets in the Peruvian highlands. A single dose of 5 mg of praziquantel was given to eliminate intestinal taeniasis in humans, and two rounds of oxfendazole (30 mg/kg) were administered to all pigs. The total population in the study villages was 5,658 resident individuals, and the porcine population at the beginning of the study was 716 pigs. Human treatment coverage was 75%, ranging from 69% to 80%. There were only a few refusals of owners for porcine treatment of their animals. The effect of the intervention was measured by comparing incidence rates (seroconversion in pigs who were seronegative 4 months before) in treatment versus control villages, before and up to 18 months after treatment. There was a clear effect in decreasing prevalence (odds ratio, 0.51; P < 0.001) and incidence (odds ratio, 0.39; P < 0.013) in the treatment area after the intervention, which did not leave to extinction of the parasite but stabilized in slightly decreased rates persisting along the follow-up period. Mass chemotherapy was effective in decreasing infection pressure in this hyperendemic area. However, the magnitude of the effect was small and did not attain the goal of eliminating transmission.

Adolescent↗
PubMed2005

Neurocysticercosis: association between seizures, serology, and brain CT in rural Peru.

BACKGROUND: Neurocysticercosis (NCC) is the commonest helminthic CNS infection and the main cause of adult-onset seizures in developing countries, also frequent in industrialized countries because of immigration from endemic zones. Although NCC is commonly seen in individuals with seizures in endemic areas, its role as a cause of epilepsy has been questioned on the basis of the poor methodology of published studies. OBJECTIVE: To determine, in a cysticercosis-endemic area of the northern Peruvian coast, the frequency of 1) epileptic seizures, 2) serum antibodies to Taenia solium, 3) NCC-compatible findings on brain CT, and 4) the associations between these variables. METHODS: A community-wide screening survey for possible seizure cases was performed using a validated questionnaire. Positive respondents were later examined in the field by neurologists. Seizure cases were categorized as single seizure, active epilepsy, or inactive epilepsy. Serology was performed for all consenting individuals using immunoblot. Noncontrast brain CT scans were performed in all individuals with seizures and two groups of control subjects without seizures (seropositive and seronegative). RESULTS: The screening survey was applied to 903 permanent residents. Most positive respondents (114/137 [83.2%]) were examined by neurologists. The overall prevalence of epilepsy was 32.1 per 1,000 and that of active epilepsy was 16.6 per 1,000. Seroprevalence was 24.2% (200/825). Seroprevalence was associated with seizures (odds ratio 2.14; p = 0.026). Brain CT abnormalities compatible with NCC were more frequent in individuals with seizures and in those seropositive. CONCLUSION: In this hyperendemic area, an important proportion of seizure cases are associated with neurocysticercosis as demonstrated by serology or brain CT.

Adolescent↗
PubMed2005

Severe gastritis in the Peruvian Andes.

OBJECTIVE: To compare the Helicobacter pylori-associated pathology in gastric biopsies taken from patients living at sea level with those taken from patients living at high altitude. METHODS AND RESULTS: We included 38 patients from a hospital in the Andean city of La Oroya, Peru, located at 3700 m in altitude, and 40 control patients taken from Comas Clinic located in the city of Lima at sea level. Fibrepanendoscopy and multiple biopsies were performed in all the patients followed by histopathological examination. In the antrum, patients from the Andean town had a higher prevalence of glandular lymphoid adherence lesions, active germinal centres, moderate to severe chronic atrophic gastritis, intestinal metaplasia and moderate to severe total deep gland loss, than did patients from the coastal town. Furthermore, the severity of the histological lesions seen in the gastric body and cardia was significantly greater in the high-altitude patients than in those from sea level. CONCLUSION: This study suggests that the severity of H. pylori-associated gastric lesions seen on histopathological examination is greater in patients living at high altitude, the cause of which is most probably multifactorial but nonetheless principally altitude related.

Adolescent↗
PubMed2005

Tuberculosis skin testing, anergy and protein malnutrition in Peru.

SETTING: Malnutrition and intestinal parasites cause immunosuppression. This may cause false-negative tuberculin skin tests (TST) and failure to identify tuberculosis (TB) infection. OBJECTIVE: To assess factors associated with TST positivity and anergy in disadvantaged communities in Peru. DESIGN: A study of 212 randomly selected adults: 102 in a rural Amazonian village and 110 shanty town residents in urban Lima. RESULTS: Respectively 52% and 53% of urban and rural jungle populations were TST-positive. Using simultaneous tetanus and candida skin tests, 99% had at least one positive skin test. Generalised anergy was therefore rare, despite frequent intestinal parasitic infection, including 34% helminth infection prevalence in the jungle. TST positivity was associated with age (P = 0.001), known TB contact (P = 0.02) and poor household ventilation (P = 0.007). TST positivity was not significantly associated with crowding, reported past TB, single/multiple BCG vaccination, income, intestinal parasites, dietary factors, body mass index or body fat. Individuals with lower anthropometric body protein, as measured by corrected arm muscle area, were less likely to be TST-positive (P = 0.02), implying that protein malnutrition caused tuberculin-specific anergy. CONCLUSION: These results identify the importance of household ventilation for community TB transmission and add to the evidence that protein malnutrition suppresses TB immunity, causing false-negative TST results.

Adolescent↗
PubMed2004

Calcific neurocysticercosis and epileptogenesis.

Neurocysticercosis is responsible for increased rates of seizures and epilepsy in endemic regions. The most common form of the disease, chronic calcific neurocysticercosis, is the end result of the host's inflammatory response to the larval cysticercus of Taenia solium. There is increasing evidence indicating that calcific cysticercosis is not clinically inactive but a cause of seizures or focal symptoms in this population. Perilesional edema is at times also present around implicated calcified foci. A better understanding of the natural history, frequency, epidemiology, and pathophysiology of calcific cysticercosis and associated disease manifestations is needed to define its importance, treatment, and prevention.

Animals↗
PubMed2004

The value of counting BCG scars for interpretation of tuberculin skin tests in a tuberculosis hyperendemic shantytown, Peru.

SETTING: The tuberculin skin test (TST) is widely used as a diagnostic or screening test for Mycobacterium tuberculosis infection and disease. A peri-urban shantytown in the desert hills of south Lima, Peru, highly endemic for tuberculosis, and where bacille Calmette-Guérin (BCG) vaccine had been given in multiple doses until 1995. OBJECTIVE: To analyze the effect of multiple BCG vaccines on TST in a community-based setting. DESIGN: Point-prevalence survey of TST reactions of 572 people aged 6-26 years from 255 households. TST reactions were compared to the observed number of BCG scars and other potential risk factors (age, living with a TST-positive person, and contact with active tuberculosis). RESULT: People with two or more scars had significantly larger reactions, even after adjusting for potential risk factors. The adjusted population attributable fraction of being TST-positive and having two or more BCG scars was 26%. CONCLUSION: There is no demonstrated benefit of repeat BCG vaccination. We therefore recommend that physicians take into consideration the number of BCG scars when interpreting the TST and that programs give no more than one BCG vaccination.

Adolescent↗
PubMed2004

Tuberculosis and nutrition: disease perceptions and health seeking behavior of household contacts in the Peruvian Amazon.

SETTING: Households of TB patients in the Peruvian Amazon. OBJECTIVE: To investigate how knowledge and beliefs of household contacts about TB affected health seeking behavior. DESIGN: Interviews with 73 patients finishing treatment and 79 of their adult household contacts. RESULTS: Contacts were knowledgeable about free screening and treatment, but contacts who noted weight loss, not cough, were more likely to be screened for TB (P = 0.03). Forty-two per cent reported that TB was prevented by nutrition, 28% by separating eating utensils, and only 19% by avoiding a coughing patient. Only one household contact reported being stigmatized. Stigma centered upon nutrition, and only 12% knew of the association between TB and HIV. Only 14% had a BMI < 20, yet 30% reported regularly going to sleep hungry. Free food packages were reported to be the most important reason for treatment adherence by 33% of patients. CONCLUSION: Contacts misperceived TB as a nutritional disease and did not fear airborne transmission, which should be corrected by public health education. Weight loss, and not cough, led to screening. Stigma appeared to be minimized because risk was perceived as personal, through malnutrition, rather than exposure-based. Nutritional incentives that utilize these beliefs may reduce diagnostic delay and enhance treatment adherence.

Adolescent↗
PubMed2003

Seroincidence of porcine T. solium infection in the Peruvian highlands.

We performed repeated serological sampling of pigs in an endemic area of the Peruvian highlands (eight villages) to assess the feasibility of detecting incident cases of Taenia solium infection as indicators of ongoing transmission of the parasite. A total of 2245 samples corresponding to 1548 pigs were collected in three sampling rounds (n=716, 926, and 603, respectively). Village-period specific seroprevalences of antibodies by enzyme-linked immunoelectrotransfer blot (EITB) assay varied from 39% (95% CI: 34, 44) to 76% (95% CI: 72, 79). The prevalence of cysticercosis increased with the age of the pigs (similarly for both sexes). Around 40% of pigs were re-sampled at the end of each 4-month period. Crude incidence risks were 48% (57/120, 95% CI: 43-52) and 58% (111/192, 95% CI: 54-61) for each period. A proportion of seropositive animals became seronegative at the end of each period (23 and 15%). Incidence varied by the village, and the exposure period, and was higher in males than females (but did not differ by age).

Age Factors↗
PubMed2003

No association between Helicobacter pylori and Mycobacterium tuberculosis infections among gastrointestinal clinic attendees in Lima, Peru.

Helicobacter pylori (HP) infection can cause hypochlorhydria, a positive risk factor for Mycobacterium tuberculosis (MTB) infection. This study examined the association between HP and MTB infections among persons attending the Policlinico Peruano Japonés Gastrointestinal Clinic in Lima, Peru. From 23 June 2000 to 18 August 2000, consenting 18-55 year olds who attended the clinic for gastric biopsy gave blood for HP serologic testing, underwent tuberculin skin testing (TST) and completed a social and medical history. Of 128 participating patients, 78 (61%) were TST positive for MTB, and 107 (84%) were infected with HP by serology. Of the patients who were HP positive, 67 (63%) developed positive TST reactions compared to 11 (52%) of 21 HP-seronegative subjects (OR 1.29; 95% CI 0.54-3.11; P = 0.6). There was no association after adjusting for covariates of H. pylori infection (OR 0.78; 95% CI 0.23-2.71; P = 0.7). However, study power was limited by high prevalence of the two infections.

Adolescent↗
PubMed2003

Taenia solium infection in a rural community in the Peruvian Andes.

An epidemiological study was conducted in a highland, rural community in Peru, to determine the seroprevalences of human and porcine infection with Taenia solium and the risk factors associated with human infection. The seroprevalences, determined using an assay based on enzyme-linked-immuno-electrotransfer blots (EITB), were 21% (66/316) in the humans and 65% (32/49) in the pigs. The human subjects aged <30 years were more likely to be positive for anti-T. solium antibodies than the older subjects (P < 0.001). The risk factors associated with human seropositivity were lack of education beyond the elementary level [odds ratio (OR)=2.69; 95% confidence interval (CI)=1.09-6.65] and pig-raising (OR=1.68; CI=0.96-2.92). Curiously, sheep-raising was inversely associated with human T. solium infection (OR=0.50; CI=0.28-0.90). The study site appears to be a new endemic focus for T. solium in the central Peruvian Andes. Although, in earlier studies, the seroprevalence of T. solium infection has generally been found to increase with age, the opposite trend was observed in the present study. The results of follow-up studies should help determine if the relatively high seroprevalence in the young subjects of the present study is the result of a transient antibody response.

Adolescent↗
PubMed2003

Gastric emptying rates in idiopathic dyspepsia with and without "hunger pain".

It has been previously observed that in dyspeptic patients with "hunger pain", that is, with pain suggestive of the presence of peptic ulcer, only 12% had an endoscopically demonstrated ulcer, the remaining 88% showing absence of important macroscopically detectable lesions (idiopathic dyspepsia). In order to investigate the possibility of a relationship between "hunger pain" and some alteration in gastroduodenal motility, the gastric emptying rates of patients presenting idiopathic dyspepsia with and without "hunger pain" were compared with those of normal control subjects. The study was conducted in 40 patients presenting idiopathic dyspepsia, 20 with and 20 without "hunger pain", and 30 voluntary apparently normal control subjects. The patients and the controls ingested, with a standard breakfast, a gelatine capsule containing 10 radioopaque polyurethane markers, and the gastric emptying of the markers was evaluated taking 3 x-ray films of the abdomen at 1.5, 3.0 and 4.5 hours after the breakfast. The gastric emptying rates of the markers were significantly higher in the patients with "hunger pain", and significantly lower in the patients without "hunger pain", than in the normal control subjects. In idiopathic dyspepsia with and without "hunger pain" there are, respectively, abnormally increased and abnormally decreased gastric emptying rates of undigestible solid markers. Our findings could help to better understand the pathogenesis of those different types of dyspepsia and, consequently, to improve their treatment.

Abdominal Pain↗
PubMed2002

Risk factors for burns in children: crowding, poverty, and poor maternal education.

OBJECTIVE: To characterize the presentation of burns in children and risk factors associated with their occurrence in a developing country as a basis for future prevention programs. DESIGN: Case-control study. SETTING: Burn unit of the National Institute of Child Health (Instituto Nacional de Salud del Niño) in Lima, Peru. METHODS: A questionnaire was administered to all consenting guardians of children admitted to the burns (cases) and general medicine (controls) units during a period of 14 months. Guardians of patients were questioned regarding etiology of the injury, demographic and socioeconomic data. RESULTS: 740 cases and controls were enrolled. Altogether 77.5% of the cases burns occurred in the patient's home, with 67.8% in the kitchen; 74% were due to scalding. Most involved children younger than 5 years. Lack of water supply (odds ratio (OR) 5.2, 95% confidence interval (CI) 2.1 to 1 2.3), low income (OR 2.8, 95% CI 2.0 to 3.9), and crowding (OR 2.5, 95%CI 1.7 to 3.6) were associated with an increased risk. The presence of a living room (OR 0.6, 95% CI 0.4 to 0.8) and better maternal education (OR 0.6, 95% CI 0.5 to 0.9) were protective factors. CONCLUSIONS: To prevent burns interventions should be directed to low socioeconomic status groups; these interventions should be designed accordingly to local risk factors.

Adolescent↗
PubMed2002

Circulating parasite antigen in patients with hydrocephalus secondary to neurocysticercosis.

End stages of neurocysticercosis include residual intraparenchymal brain calcifications and hydrocephalus. Although brain calcifications alone have a benign prognosis, hydrocephalus is frequently associated with chronic inflammation and intracranial hypertension, together with a protracted clinical evolution, and may lead to patient deaths. By using a monoclonal-based antigen detection enzyme-linked immunosorbent assay, we measured the levels of circulating parasite antigen in the sera of 56 patients with neurocysticercosis: 27 with calcifications only and 29 with hydrocephalus. The assay gave positive results in 14 of 29 patients with hydrocephalus but was consistently negative in patients with calcifications. Circulating parasite antigen in hydrocephalus secondary to neurocysticercosis indicates the presence of live parasites in these patients and thus a potential benefit from antiparasitic therapy.

Adult↗
PubMed2001

Proposed diagnostic criteria for neurocysticercosis.

Neurocysticercosis is the most common helminthic infection of the CNS but its diagnosis remains difficult. Clinical manifestations are nonspecific, most neuroimaging findings are not pathognomonic, and some serologic tests have low sensitivity and specificity. The authors provide diagnostic criteria for neurocysticercosis based on objective clinical, imaging, immunologic, and epidemiologic data. These include four categories of criteria stratified on the basis of their diagnostic strength, including the following: 1) absolute--histologic demonstration of the parasite from biopsy of a brain or spinal cord lesion, cystic lesions showing the scolex on CT or MRI, and direct visualization of subretinal parasites by funduscopic examination; 2) major--lesions highly suggestive of neurocysticercosis on neuroimaging studies, positive serum enzyme-linked immunoelectrotransfer blot for the detection of anticysticercal antibodies, resolution of intracranial cystic lesions after therapy with albendazole or praziquantel, and spontaneous resolution of small single enhancing lesions; 3) minor--lesions compatible with neurocysticercosis on neuroimaging studies, clinical manifestations suggestive of neurocysticercosis, positive CSF enzyme-linked immunosorbent assay for detection of anticysticercal antibodies or cysticercal antigens, and cysticercosis outside the CNS; and 4) epidemiologic--evidence of a household contact with Taenia solium infection, individuals coming from or living in an area where cysticercosis is endemic, and history of frequent travel to disease-endemic areas. Interpretation of these criteria permits two degrees of diagnostic certainty: 1) definitive diagnosis, in patients who have one absolute criterion or in those who have two major plus one minor and one epidemiologic criterion; and 2) probable diagnosis, in patients who have one major plus two minor criteria, in those who have one major plus one minor and one epidemiologic criterion, and in those who have three minor plus one epidemiologic criterion.

Humans↗