Endogenous, non-reducing end glycosaminoglycan biomarkers are superior to internal disaccharide glycosaminoglycan biomarkers for newborn screening of mucopolysaccharidoses and GM1 gangliosidosis.

Measurement of enzymatic activity in newborn dried blood spots (DBS) is the preferred first-tier method in newborn screening (NBS) for mucopolysaccharidoses (MPSs). Our previous publications on glycosaminoglycan (GAG) biomarker levels in DBS for mucopolysaccharidosis type 1 (MPS-I) and MPS-II demonstrated that second-tier GAG biomarker analysis can dramatically reduce the false positive rate in NBS. In the present study, we evaluate two methods for measuring GAG biomarkers in seven MPS types and GM1 gangliosidosis.

Evaluation of Two Methods for Quantification of Glycosaminoglycan Biomarkers in Newborn Dried Blood Spots from Patients with Severe and Attenuated Mucopolysaccharidosis Type II.

All newborn screening (NBS) for mucopolysaccharidosis-I and -II (MPS-I and MPS-II) is carried out via the measurement of α-iduronidase (IDUA) and iduronate-2-sulfatase (IDS) enzymatic activity, respectively, in dried blood spots (DBS). The majority of low enzyme results are due to pseudodeficiencies, and data from recent MPS-II population screenings and studies from the Mayo Clinic show that the false positive rate can be dramatically reduced by the inclusion of a second-tier analysis of glycosaminoglycans (GAGs) in DBS as part of NBS. In the present study, which focused on MPS-II, we obtained newborn DBS from 17 patients with severe MPS-II, 1 with attenuated MPS-II, and 6 patients with various IDS pseudodeficiencies.

Evaluation of Multiple Methods for Quantification of Glycosaminoglycan Biomarkers in Newborn Dried Blood Spots from Patients with Severe and Attenuated Mucopolysaccharidosis-I.

All newborn screening (NBS) for mucopolysaccharidosis-I (MPS-I) is carried out by the measurement of α-iduronidase (IDUA) enzymatic activity in dried blood spots (DBS). The majority of low enzyme results are due to pseudodeficiencies, and studies from the Mayo Clinic have shown that the false positive rate can be greatly reduced by including a second-tier analysis of glycosaminoglycans (GAGs) in DBS as part of NBS. In the present study, we obtained newborn DBS from 13 patients with severe MPS-I and 2 with attenuated phenotypes.

Population genetic structure of the dengue mosquito Aedes aegypti in Venezuela.

The mosquito Aedes aegypti is the main vector of dengue in Venezuela. The genetic structure of this vector was investigated in 24 samples collected from eight geographic regions separated by up to 1160 km. We examined the distribution of a 359-basepair region of the NADH dehydrogenase subunit 4 mitochondrial gene among 1144 Ae.

Genetic diversity of merozoite surface protein-1 gene of Plasmodium vivax isolates in mining villages of Venezuela (Bolivar State).

The merozoite surface protein-1 gene of Plasmodium vivax is highly polymorphic and so, currently used in epidemiological studies of P. vivax malaria. We sequenced the variable block 5 of the gene from 39 Venezuelan isolates, 18 of which were co-infected with Plasmodium falciparum.

Detection of dengue viruses in field-caught Aedes aegypti (Diptera: Culicidae) in Maracay, Aragua state, Venezuela by type-specific polymerase chain reaction.

Virological surveillance of dengue viruses in Aedes aegypti populations constitutes a powerful tool for early prediction of dengue outbreaks. We have standardized a protocol for viral RNA extraction from individual and pools of mosquitoes that permits a sensitive detection of dengue virus without RNA degradation or PCR inhibition when we apply a semi-nested RT-PCR. The limit of detection for each dengue serotype was 0.

Plasminogen interaction and activation on Streptococcus mutans surface.

A number of pathogenic microorganisms have been previously shown to bind plasminogen. The subsequent activation of plasminogen into plasmin can contribute to their virulence. In this study, we have shown that Streptococcus mutans is able to bind both human plasminogen and plasmin.

Evidence for clonal propagation in natural isolates of Plasmodium falciparum from Venezuela.

We have analyzed 75 isolates of Plasmodium falciparum, collected in Venezuela during both the dry (November) and rainy (May-July) seasons, with a range of genetic markers including antigen genes and 14 random amplified polymorphic DNA (RAPD) primers. Thirteen P. falciparum stocks from Kenya and four other Plasmodium species are included in the analysis for comparison.

The nasogastric tube syndrome: two case reports and review of the literature.

Background: The nasogastric tube syndrome is a potentially life-threatening complication of an indwelling nasogastric (NG) tube. The syndrome is thought to result from ulceration and infection of the posterior cricoid region with subsequent dysfunction of vocal cord abduction. This dysfunction may present as complete loss of vocal cord abduction manifested as serious airway compromise.

Point mutations in dihydrofolate reductase and dihydropteroate synthase genes of Plasmodium falciparum isolates from Venezuela.

The present study was designed to characterize mutations in dihydrofolate reductase (DHFR) and dihydropteroate synthase (DHPS) genes of Plasmodium falciparum in the Bolivar region of Venezuela, where high levels of clinical resistance to sulfadoxine-pyrimethamine (SP, Fansidar; F. Hoffman-La Roche, Basel, Switzerland) has been documented. We used a nested mutation-specific polymerase chain reaction and restriction digestion methods to measure 1) the prevalence of DHFR mutations at 16, 50, 51, 59, 108, and 164 codon positions, and 2) the prevalence of mutations in the 436, 437, 581, and 613 codon sites in DHPS gene.

Evaluation of DNA recombinant methodologies for the diagnosis of Plasmodium falciparum and their comparison with the microscopy assay.

Since 1984, DNA tests based on the highly repeated subtelomeric sequences of Plasmodium falciparum (rep 20) have been frequently used in malaria diagnosis. Rep 20 is very specific for this parasite, and is made of 21 bp units, organized in repeated blocks with direct and inverted orientation. Based in this particular organization, we selected a unique consensus oligonucleotide (pf-21) to drive a PCR reaction coupled to hybridization to non-radioactive labeled probes.

Spigelian hernia: diagnosis by high-resolution real-time sonography.

The purpose of this study was to demonstrate the role of high-resolution real-time sonography in the diagnosis of spigelian hernias. The sonographic findings in three patients, two of whom had surgical confirmation, are presented. We also discuss and demonstrate the anatomic and pathologic factors that predispose to these hernias.

Pleomorphic melanoma mimicking sarcoma.

Malignant melanoma may display a wide variety of unusual morphologic patterns that simulate unrelated neoplasms. The diagnostic approach to such complex and morphologically divergent lesions requires thorough and extensive scrutiny not only by routine light microscopy, but also by immunohistochemical and ultrastructural evaluation. We have reported the case of a patient with a mass on the heel exhibiting complex morphology that illustrates the value of such a systematic approach.

Adenocarcinoma of the vermiform appendix.

Primary adenocarcinoma of the appendix is rare. Eleven patients with this rare neoplasm have been evaluated at our institution over a 50-year period. We have reviewed the presentation and clinical course of these patients, and have compared them with those described in the literature.

The prevalence and severity of late effects in normal rat duodenum following intraoperative irradiation.

In humans, a portion of the duodenum is often at risk for radiation-induced complications following intraoperative radiation therapy for pancreatic carcinoma. To determine experimentally the prevalence and severity of late effects in the normal mammalian duodenum, 190 rats received single doses of 0, 15, 20, 25, 30, or 40 Gy orthovoltage X rays to temporarily exteriorized 3 cm circumferential segments of duodenum. The animals were killed 2, 6, 8, or 10 months later.

Gastrointestinal carcinoid tumor metastatic to the orbit.

Primary gastrointestinal carcinoid tumors rarely metastasize to the orbit, but an aggressive approach is warranted for any patient with a history of carcinoid tumor and ocular complaints. The diagnosis can be established only by obtaining tissue for histologic examination. Treatment, usually with radiation, can result in symptomatic improvement and should be considered after confirmation of the diagnosis.

Factitious microcalcifications in breast biopsy material: laboratory-induced error by use of tattoo powder for specimen mammography.

A xeromammogram led to the surgical excision of a calcified breast lesion on a 66-year-old female. Before specimen mammography was performed, the excised tissue was oriented with tattoo pigment. The specimen mammogram then revealed multiple calcifications caused by unsuspected radio-opaque material in the tattoo pigment, and the original calcifications were obscured.

Rational ordering of cervical spine radiographs following trauma.

A retrospective review of 312 hospitalized patients with cervical spine injuries was conducted to identify presenting signs, symptoms, and coexisting conditions, and to determine if any injuries were not diagnosed in the emergency department. Of the 257 (82%) patients who were alert on ED evaluation, 215 (84%) complained of neck pain or tenderness. Of the remaining 42 alert patients without neck pain, 34 had sensory or motor symptoms or signs suggestive of cervical spine injury, and eight had significantly painful other injuries.

Intraoperative irradiation in a rat model: histopathological changes in irradiated segments of duodenum.

During intraoperative radiation therapy for carcinoma of the head of the pancreas in humans, a portion of duodenum is often at risk for radiation-induced complications because of its fixed anatomical position within the treatment field. This study was undertaken to determine the feasibility of using the rat as a model to determine the radiotolerance of normal mammalian duodenum. The procedures used to exteriorize and irradiate a selected segment of duodenum are described.

Role of an emergency helicopter transport service in rural trauma.

The records of 916 trauma victims transported by an emergency helicopter service were reviewed to evaluate its impact on patient outcome. According to strict criteria, the service was classified as essential, helpful, or "not a factor" in the preservation of life and/or limb in each case. The helicopter service was essential in 14.

High-resolution sonography of acute appendicitis.

During a 7-month period high-resolution sonography was used in the evaluation of 68 patients with an equivocal clinical diagnosis of acute appendicitis. The sonographic findings were correlated with surgical-pathologic outcome in 32 cases and with clinical follow-up in the remainder. This technique was found to be accurate in the diagnosis of acute appendicitis with a specificity of 95%, a sensitivity of 80%, and an accuracy of 90%.

Malignant melanoma in childhood and adolescence.

A retrospective chart review of 25 patients under the age of 20 years with malignant melanoma, diagnosed between the years 1938 and 1984 at the University of Iowa Hospitals and Clinics, was conducted. Nine of the patients were under the age of 14 years, and 18 patients were females. There appeared to be a frequent delay in diagnosis of the primary lesion, occasionally incorrect initial diagnosis, and under-treatment in these young patients.