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Biomedical subjects

T A Klein

Publications and source records attributed to T A Klein.

At least 19 recordsLinked to original sources
PubMed2000

Vector competence of Peruvian mosquitoes (Diptera: Culicidae) for epizootic and enzootic strains of Venezuelan equine encephalomyelitis virus.

Mosquitoes collected in the Amazon Basin, near Iquitos, Peru, were evaluated for their susceptibility to epizootic (IAB and IC) and enzootic (ID and IE) strains of Venezuelan equine encephalomyelitis (VEE) virus. After feeding on hamsters with a viremia of approximately 10(8) plaque-forming units of virus per milliliter, Culex (Melanoconion) gnomatus Sallum, Huchings, & Ferreira, Culex (Melanoconion) vomerifer Komp, and Aedes fulvus (Wiedemann) were highly susceptible to infection with all four subtypes of VEE virus (infection rates > or = 87%). Likewise, Psorophora albigenu (Peryassu) and a combination of Mansonia indubitans Dyar & Shannon and Mansonia titillans (Walker) were moderately susceptible to all four strains of VEE virus (infection rates > or = 50%). Although Psorophora cingulata (Fabricius) and Coquillettidia venezuelensis (Theobald) were susceptible to infection with each of the VEE strains, these two species were not efficient transmitters of any of the VEE strains, even after intrathoracic inoculation, indicating the presence of a salivary gland barrier in these species. In contrast to the other species tested, both Culex (Melanoconion) pedroi Sirivanakarn & Belkin and Culex (Culex) coronator Dyar & Knab were nearly refractory to each of the strains of VEE virus tested. Although many of the mosquito species found in this region were competent laboratory vectors of VEE virus, additional studies on biting behavior, mosquito population densities, and vertebrate reservoir hosts of VEE virus are needed to incriminate the principal vector species.

Animals↗
PubMed2000

Field evaluation of deet and a piperidine repellent against Aedes communis (Diptera: Culicidae) and Simulium venustum (Diptera: Simuliidae) in the Adirondack Mountains of New York.

Repellent efficacy of N,N-diethyl-3-methyl-benzamide (deet), the piperidine, 1-[3-cyclohexen-1-ylcarbonyl]-2-methylpiperidine (AI3-37220), and a 1:1 ratio of deet + AI3-37220 were evaluated topically (0.25 mg/cm2 applied in ethanol solution) on human volunteers against the mosquito Aedes communis (DeGeer) and the black fly Simulium venustum Say. The average repellency of all three formulations was > 95% at 4 h. For both mosquitoes and black flies, deet alone provided < 90% protection at 6 h, whereas AI3-37220 provided > 95% protection. Although repellent treatments were not significantly different overall, the contrasts between AI3-3720 versus deet were significant at 6 and 8 h. The 95% confidence interval on percent repellency at 6 h ranged from 90.1 to 98.9% for AI3-37220 versus 64.3 to 82.2% for deet, and at 8 h ranged 76.1 to 88.5% for AI3-37220 versus 47.8 to 64.0% for deet. Similarly, the confidence interval for protection against black flies at 6 h by (AI3-37220 ranged from 86.3 to 99.5% and did not overlap with the confidence interval provided by deet alone (51.2 to 78.8%). There was no evidence of synergistic repellency from a combination of the two compounds; i.e., protection from combined compounds was no better than either repellent used alone.

Aedes↗
PubMed2000

Limited potential for transmission of live dengue virus vaccine candidates by Aedes aegypti and Aedes albopictus.

To evaluate the transmission risk of four live dengue (DEN) vaccine candidates developed by the U.S. Army (DEN-1, 45AZ5 PDK 20; DEN-2, S16803 PDK 50; DEN-3, CH53489 PDK 20; and DEN-4, 341750 PDK 20), we tested 3,010 Aedes aegypti and 1,576 Aedes albopictus mosquitoes blood-fed on 21 volunteers who had been administered one of the four vaccine candidates or the licensed yellow fever (YF) vaccine (17D). We used an indirect immunofluorescence assay (IFA) to detect DEN or YF viral antigen in the heads of mosquitoes. Corresponding to the lack of a detectable viremia among volunteers inoculated 8-13 days previously with live DEN-1 or DEN-2 vaccine candidates, only six mosquitoes developed disseminated infections after feeding on these volunteers. These six mosquitoes included 4 of 247 Ae. albopictus fed on volunteers inoculated with the DEN-1 vaccine candidate and 2 of 528 Ae. aegypti fed on volunteers inoculated with the DEN-2 vaccine candidate. Infection was confirmed in each of these IFA-positive mosquitoes by isolating infectious virus from the mosquito's body in Vero-cell culture. None of the 1,252 or the 969 mosquitoes fed on DEN-3 or DEN-4 recipients, respectively, were infected. Overall, dissemination rates in Ae. albopictus and Ae. aegypti were low. Dissemination rates were 0.5%, 0.3%, < 0.1%, and < 0.1% for the DEN-1 through DEN-4 vaccine candidates, respectively. Because of the observed low dissemination rates, it is unlikely that these vaccine viruses would be transmitted under natural conditions.

Aedes↗
PubMed1999

Laboratory evaluation of AI3-37220, AI3-35765, CIC-4, and deet repellents against three species of mosquitoes.

Four repellents, N,N-diethyl-3-methyl-benzamide (deet), 2-hydroxy-methyl-cyclohexyl acetic acid lactone (CIC-4), and 2 piperidines (1-[3-cyclohexen-1-ylcarbonyl] piperidine [AI3-35765] and 1-[3-cyclohexen-1-ylcarbonyl]-2-methylpiperidine [AI3-37220]) were evaluated alone and in combination against Aedes aegypti, Anopheles stephensi, and Culex quinquefasciatus using a modified in vitro test system. This method was a valuable tool for comparing effective concentrations of the new compounds. Because of the controlled conditions of the test, it was possible to use the results of assays that had been conducted over a 5-year period and to perform the many replications necessary to evaluate combinations of compounds. The new candidate repellents were generally as effective as deet. Although speculative at this time, there was some evidence of synergistic interaction. Repellent combinations of CIC-4/AI3-37220/AI3-35767, deet/AI3-35765, and deet/AI3-37220/AI3-35765 against An. stephensi and CIC-4/AI3-35765, deet/AI3-37220/AI3-35765, AI3-37220/AI3-35765, and CIC-4/AI3-37220 against Ae. aegypti were more effective than the component compounds alone.

Aedes↗
PubMed1998

Effect of freezing on calpastatin activity and tenderness of callipyge lamb.

The longissimus muscles (LM) from 12 lambs (eight = callipyge [CLPG] and four = normal [NML]; 48 kg) were used to 1) assess the effect of freezing with or without prior immersion in liquid nitrogen on calpastatin activity (CA) and on Warner-Bratzler shear force (WBS) in CLPG, 2) determine the freezing time required to reduce CA and WBS of CLPG to that of NML, and 3) compare sensory panel ratings for CLPG that is aged fresh to CLPG that is aged after freezing. At 24 h postmortem, chops (.64 and 2.54 cm) were removed from each CLPG LM and randomly assigned within side to one of six freezing times (0, 2, 4, 8, 20, and 42 d). Left-side chops were vacuum-packaged and frozen at -20 degrees C for the assigned time (FROZEN) and right-side chops were treated similarly, except that they were frozen in liquid nitrogen first (FLASH). After freezing for the assigned time, the .64-cm chop was immediately assayed for CA, and 2.54-cm chop was thawed, aged at 2 degrees C for 14 d, and refrozen for subsequent WBS measurement. Chops (.64 and 2.54 cm) were also removed from the longissimus of NML lamb carcasses. The d-0 CLPG and NML chops (2.54 cm) were vacuum-packaged, aged at 2 degrees C for 14 d, and frozen for subsequent WBS measurement. Calpastatin activity did not differ between freezing treatments (P = .99) or with the freezing treatment x freezing time interaction (P = .80). Freezing reduced (P = .01) CA in CLPG by 44% from d 0 to d 42. Calpastatin activity for CLPG was similar (P > .05) to that of NML lamb after freezing for 8, 20, or 42 d. Freezing at -20 degrees C for 42 d and then aging for 14 d reduced (P = .01) WBS in CLPG by 44% from d-0 values. Shear force values for CLPG-FROZEN were similar (P > .05) to NML after 8, 20, or 42 d of freezing. Sensory panel tenderness scores were higher (P < .05) for CLPG aged after freezing 42 d than for those aged fresh. Juiciness and flavor ratings did not differ (P > .05) between CLPG aged fresh or after freezing. Freezing for at least 8 d before aging seems to be a viable method for increasing the tenderness of CLPG LM without reducing juiciness or flavor ratings.

Adult↗
PubMed1996

Office gynecology for the primary care physician, part II: pelvic pain, vulvar disease, disorders of menstruation, premenstrual syndrome, and breast disease.

Approaches to patients with pelvic pain, vulvar disease, disorders of menstruation, premenstrual syndrome, and breast diseases are addressed. In the great majority of cases, it is appropriate for the primary care physician to initiate evaluation and management of these problems. It is hoped that the brief introductions contained here suggest a diagnostic approach to each disorder and guide referral to consultants as needed.

Breast Diseases↗
PubMed1996

Laboratory and field evaluation of deet, CIC-4, and AI3-37220 against Anopheles dirus (Diptera: Culicidae) in Thailand.

Laboratory and field tests of the repellents diethyl methylbenzamide (deet), 1-(3-Cyclohexen-1-yl-carbonyl)-2-methylpiperidine (AI3-37220), and (2-hydroxymethylcyclohexyl) acetic acid lactone (CIC-4) were conducted against Anopheles dirus Peyton & Harrison, the principal malaria vector in Thailand. In the laboratory, An. dirus was more sensitive to CIC-4 than either AI3-37220 or deet. The duration of protection provided by each repellent in laboratory tests increased with higher concentrations of repellents and when exposed in cages containing fewer mosquitoes. A field study in Chanthaburi Province, southeastern Thailand, during November 1993 tested 25% (wt:wt) ethanol solutions of each repellent against An. dirus. In contrast to the laboratory experiments, protection provided by AI3-37220 was significantly better than either deet or CIC-4 and there was no significant difference between deet and CIC-4. Protection provided by deet and CIC-4 fell to below 95% 2 h after repellent application, whereas AI3-37220 provided > 95% protection for 4 h. The protection provided by all repellents fell to < or = 65% 7 h after repellent application.

Aedes↗
PubMed1996

Plasmodium falciparum and P. vivax circumsporozoite proteins in anophelines (Diptera: Culicidae) collected in eastern Thailand.

In total, 414 anophelines, consisting of Anopheles karwari (James), An. splendidus Koidzumi, An. dirus Peyton & Harrison, and An. barbirostris Van der Wulp were collected in 2 provinces in eastern Thailand and tested by enzyme-linked immunosorbent assay for the presence of circumsporozoite proteins. Plasmodium vivax CS protein was detected in 3.4% (2/54) of An. karwari and 4.8% (2/42) of An. barbirostris specimens. Both P. vivax phenotypes, Pv247 and Pv210, were found in An. karwari, whereas only Pv247 was detected in An. barbirostris. Plasmodium falciparum CS protein was detected only in 0.3% (1/276) of An. dirus. Results indicate that An. barbirostris may play a role in the transmission of P. vivax in Chanthaburi Province, Thailand.

Animals↗
PubMed1996

Field evaluation of arthropod repellents, deet and a piperidine compound, AI3-37220, against Anopheles funestus and Anopheles arabiensis in western Kenya.

A field evaluation of the repellents N,N-diethyl-3-methylbenzamide (deet) and 1-(3-cyclohexen-1-yl-carbonyl)-2-methylpiperidine (AI3-37220, a piperidine compound) was conducted against Anopheles funestus and An. arabiensis in Kenya. Both repellents provided significantly more protection (P < 0.001) than the ethanol control. AI3-37220 was significantly more effective (P < 0.001) than deet in repelling both species of mosquitoes. After 9 h, 0.1 mg/cm2 of AI3-37220 provided 89.8% and 71.1% protection against An. arabiensis and An. funestus, respectively. Deet provided > 80% protection for only 3 h, and protection rapidly decreased after this time to 60.2% and 35.1% for An. arabiensis and An. funestus, respectively, after 9 h. Anopheles funestus was significantly less sensitive (P < 0.001) to both repellents than An. arabiensis. The results of this study indicate that AI3-37220 is more effective than deet in repelling anopheline mosquitoes in western Kenya.

Adult↗
PubMed1995

Diagnosis by random amplified polymorphic DNA polymerase chain reaction of four cryptic species related to Anopheles (Nyssorhynchus) albitarsis (Diptera: Culicidae) from Paraguay, Argentina, and Brazil.

Random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) analysis was applied to samples from widespread populations of the poorly characterized Anopheles (Nyssorhynchus) albitarsis Lynch-Arribálzaga species complex, and 4 genetically differentiated species were distinguished. A screen of 65 random decamer oligonucleotide primers identified 12 primers, which produced 19 reproducible species-specific genetic markers and 4 markers common to 2 or more species. These markers were correlated in nearly all individuals of each species throughout the ranges sampled, including populations as far apart as 2,500 km. Each individual analyzed was from a different isofemale progeny brood, with associated morphological specimens. These specimens will facilitate studies to relate these species to previously reported chromosomal and enzymatic variation as well as to their feeding behavior and potential as malaria vectors. We hypothesize that 3 of the species have recognized valid names: An. (Nys.) albitarsis Lynch-Arribálzaga, An. (Nys.) marajoara Galvão and Damasceno, and An. (Nys.) deaneorum Rosa-Freitas, whereas the 4th is undescribed.

Animals↗
PubMed1995

Field evaluation of deet and a piperidine repellent (AI3-37220) against Amblyomma americanum (Acari: Ixodidae).

Repellent efficacy of deet (N,N-diethyl-3-methylbenzamide) and a piperidine, AI3-37220, was evaluated topically on human volunteers against lone star tick, Amblyomma americanum (L.), nymphs and adults in the field. AI3-37220, at 0.5 mg/cm2, provided > 90% repellency against adult and nymphal ticks over a 6-h test period and showed significantly better repellent efficacy than deet. Deet, at the same concentration, provided 85% repellency at 0 h and deteriorated to 55% repellency at 6 h.

Animals↗
PubMed1995

Response of wild Anopheles funestus to repellent-protected volunteers is unaffected by malaria infection of the vector.

A field experiment was conducted to compare the biting behavior of Plasmodium falciparum-infected and uninfected Anopheles on humans using mosquito repellents. Repellent formulations (5% [wt/vol] N,N-diethyl-3-methylbenzamide [deet] or 5% [wt/vol] AI3-37220, a piperidine compound, both in 100% ethanol, or 100% ethanol alone [as a control]) were applied to the lower legs of 3 collectors in each of 4 houses. Collectors caught mosquitoes over 6 collection nights. Mosquitoes were collected into vials after they initiated probing on the leg of a collector. Infected females made up the same proportion of the Anopheles funestus populations biting either repellent-protected or unprotected individuals. We conclude that repellent formulations are equally effective against Plasmodium-infected and uninfected An. funestus.

Animals↗
PubMed1994

Laboratory and field trials of four repellents with Culex pipiens (Diptera: Culicidae).

During Operation "Desert Shield," 16 volunteers field-tested four insect repellents (deet, the lactone CIC-4, and the piperidine compounds AI3-37220 and AI3-35765) against biting mosquitoes at King Fahd Airport, Eastern Province, Saudi Arabia. CIC-4 and AI3-37220 (25% wt/vol) provided effective (> 90%) protection against bites for 4 h. Deet and AI3-35765 protected for only 2 h. The compounds subsequently were evaluated for repellency against laboratory-reared Culex pipiens L. CIC-4 was more effective than deet, AI3-37220, or AI3-35765 at the ED50 but not at the ED95 level in initial sensitivity tests using human volunteers. At the ED95 level, deet provided significantly better protection than either piperidine compound. In laboratory duration tests, AI3-37220 provided 8 h of effective (> 90%) protection against Cx. pipiens bites, deet and AI3-35765 7 h of protection, and CIC-4 2 h of protection.

Animals↗
PubMed1994

Characterization of peripheral blood and peritoneal fluid mononuclear cell subsets in fertile and infertile women.

Mononuclear cell subpopulations from the peripheral blood (PB) and peritoneal fluid (PF) of fertile and infertile women were quantified by flow cytometry using a double-staining monoclonal antibody technique. No differences in the percentage distribution of mononuclear cells between fertile and infertile women were demonstrated when either the PB constituents or the PF components were compared to one another. When the mononuclear cell composition in the PB was compared with that in the PF however, the percentage of PF-activated T cells and monocytes was increased in both fertile and infertile women as opposed to that in the PB, while there was a decrease in T helper cells (fertile and infertile women) and natural killer cells (fertile women and infertile women with endometriosis). Even though shifts do exist in the immunocytes of PF from fertile and infertile women, evidence is lacking that the PF is an immunologic mediator of infertility.

Antibodies, Monoclonal↗
PubMed1994

Prevention of sporogony of Plasmodium falciparum and P. berghei in Anopheles stephensi mosquitoes by transmission-blocking antimalarials.

The sporontocidal activity of three 8-aminoquinolines, a 1,4-naphthoquinone, and three dihydroacridine-diones was determined against the ANKA clone of Plasmodium berghei and both chloroquine-sensitive (NF54) and chloroquine-resistant (7G8) P. falciparum. Anopheles stephensi mosquitoes previously fed on P. berghei--infected mice or P. falciparum--infected cultures were refed on uninfected mice treated previously with a given drug. Sporontocidal activity was determined by assessing both oocyst and sporozoite development. Neither primaquine nor menoctone exhibited sporontocidal activity against P. berghei or either strain of P. falciparum at a dose of 100 mg base drug/kg mouse body weight, whereas the other five compounds each effectively interrupted the sporogonic development of all three parasite strains at this dose. These data clearly demonstrate that experimental dihydroacridine-diones and 8-aminoquinolines are capable of interrupting the sporogonic development of P. berghei and chloroquine-sensitive and chloroquine-resistant P. falciparum. These data also suggest that the P. berghei model may be used to accurately predict sporontocidal activity against P. falciparum.

Animals↗
PubMed1994

The effect of a surgical lubricant on in vivo sperm penetration of cervical mucus.

The implications of these data is that coital lubricants may impair fertility of some couples. Unfortunately, conception was not an end point on this study, and our conclusions must be considered inferential. Nevertheless, the results from this study lead us to recommend avoidance of surgical lubricants by couples attempting pregnancy.

Adult↗
PubMed1993

Genetic evidence for the existence of cryptic species in the Anopheles albitarsis complex in Brazil: allozymes and mitochondrial DNA restriction fragment length polymorphisms.

Allozyme and mitochondrial DNA (mtDNA) restriction studies were undertaken to determine the extent of genetic divergence among field populations of Anopheles albitarsis in Brazil. Two sympatric species, An. deaneorum and An. marajoara, were identified in collections from Costa Marques (CM), Rondonia. Genetic evidence includes (1) the presence of two types of individuals, each with diagnostic allelic clusters (for Had-1, Pgi-1, Pep-1, Mpi-1, and Idh-1), (2) a deficiency of heterozygotes, and (3) characteristic mtDNA haplotypes. In addition, two allopatric cryptic species of An. marajoara were identified, one from Iguape (An. marajoara form IG), Sao Paulo state, and the other from the Island of Marajo (An. marajoara form MA). Though form IG and form-MA resemble form CM in wing spot morphology, they differ from it in diagnostic allozymes and mtDNA haplotypes. An. marajoara form CM had a higher variability (mean heterozygosity, H = 0.22, and percentage of polymorphic loci, P = 66.7) than did form IG and form MA (H = 0.08 in both, and P = 25.0 and 33.3, respectively). Form MA and form IG are genetically more similar to each other than both are to form CM. Based on wing morphology, estimates of F statistics, and genetic similarities, we propose that An. albitarsis in Brazil is a species complex. It comprises at least two morphologically distinguishable species: (1) An. deaneorum (currently one taxon) and (2) the An. marajoara species complex, which further consists of at least three cryptic forms, marajoara form MA, marajoara form IG, and marajoara form CM.

Alleles↗