New HLA polymorphism detection by molecular and serologic typing procedures. Complete coding region characterization of Cw*0525, Cw*0825, B*3950 and A*3219N alleles

Four new HLA class I alleles, Cw*0525, Cw*0825, B*3950 and A*3219N, have been characterized.

Characterization of the novel HLA-A*3217 allele in two Caucasian Spanish donors

A novel human leukocyte antigen-A allele, officially named A*3217, was found in two unrelated Spanish donors. A*3217 differs from A*320101 in a point mutation at codon 70 (CAC-->CAG), generating an amino acid substitution of His to Gln.

Sequencing of four new HLA-C alleles, Cw*070403, Cw*0757, Cw*1705, and Cw*0223

Sequencing-based typing for unrelated hematopoietic stem cell transplantation studies rendered four new HLA-C alleles. HLA-Cw*0757, Cw*070403, and Cw*1705 differ by single point mutations from their most similar alleles, Cw*070105, Cw*070401, and Cw*1701, respectively. In contrast, Cw*0223 discloses five amino acid replacements at the alpha2 domain regarding Cw*020202.

Sequencing of new HLA-A*3025 and HLA-Cw*0221 alleles found in Caucasian donors

Two new human leukocyte antigen (HLA) class I alleles, A*3025 and Cw*0221, were identified in Spanish Caucasian donors by polymerase chain reaction-sequence-specific oligonucleotide and subsequently characterized by full coding region sequencing. HLA-A*3025 shows a single amino acid replacement at residue 70 (H>Q) compared with A*300201. HLA-Cw*0221 differs from Cw*020202 by a change at position 14 (H>Q).

New HLA-A allele, A*0339, identified in a Spanish patient

A novel human leukocyte antigen-A allele, officially named A*0339, was found in a patient when sequence-based typing was carried out for unrelated stem cell donor search. A*0339 differs from A*03010101 in a point mutation at codon 102 (GAC-->TAC), generating an exchange of amino acid from Asp to Tyr.

Sequencing of a novel HLA-DRB1*07 allele with a new polymorphism at amino acid position 21 (DRB1*0715)

DRB1*0715 differs from DRB1*070101 in a point nucleotide mutation at codon 21 (ACG-->AAG), which produces an amino acid residue change from T to K.

HLA-A*020115 and HLA-Cw*030203 show new synonymous mutations in exon 4

Two novel human leukocyte antigen (HLA) class I alleles, A*020115 and Cw*030203, were completely characterized by sequencing-based typing. Both present synonymous new HLA polymorphisms at exon 4. A*020115 shows a single nucleotide change regarding A*02010101 at codon 245 GCG > GCC). In contrast, Cw*030203 differs from Cw*030202 in a point mutation at codon 271 (ACC > ACT).

The new HLA-C allele, Cw*0220, shows a new polymorphism at amino acid position 169

The new human leukocyte antigen (HLA)-C allele, Cw*0220, was identified in a Spanish Caucasian patient by sequence-based typing. HLA-Cw*0220 differs from Cw*020202 by a single amino acid replacement at constant position 169 (R > H).

HLA-A*68020103 shows an eight nucleotides deletion within intron 2 but has normal mRNA splicing and serological recognition

A novel A*68020103 allele was completely characterized by sequencing in a Spanish bone marrow donor. A*68020103 has an eight nucleotides deletion at the 5'-end of intron 2, when compared with other A*6802 alleles. This alteration does not affect either its mRNA splicing process or serological detection.

The effects of restraint stress on the neuropathogenesis of Theiler's virus infection II: NK cell function and cytokine levels in acute disease

Psychological stress is thought to play an important role in multiple sclerosis. We have been investigating the role of restraint stress in Theiler's virus infection in mice as a model for multiple sclerosis. We have previously determined that restraint stressed CBA mice had higher levels of mortality following infection with Theiler's virus. We proposed that this was due to high levels of stress-induced corticosterone, which resulted in decreased numbers of circulating lymphocytes, decreased inflammatory cell infiltrates into the brain and consequently decreased viral clearance from the central nervous system (CNS). The effect of restraint stress on the innate immune response to Theiler's virus is further investigated in the current study. Restraint stressed mice developed clinical signs of encephalitis, thymic atrophy, and adrenal hypertrophy. Decreased numbers of circulating lymphocytes and increased numbers of neutrophils were observed in the stressed mice. Stressed mice also had lower numbers of spleen cells which correlated with the decreased numbers of lymphocytes in circulation. Restraint stress caused elevations in serum tumor necrosis alpha (TNF-alpha). Virus-induced natural killer cell (NK) cytotoxic activity was significantly reduced in restrained mice at one day post infection which may account for the reduced viral clearance from the CNS. These data suggest that stress-induced immunosuppression of cytolytic NK cell activity may account in part for the reduced ability to clear virus from the CNS and increased mortality observed in this model.

Effects of the DT-diaphorase inhibitor dicumarol on striatal monoamine levels in L-DOPA and L-deprenyl pre-treated rats

It has been proposed that DT-diaphorase plays a strategic role as a neuroprotective enzyme for monoamine neurons, perhaps together with monoamine oxidase (MAO). Thus, we investigated the long-term effects produced by DT-diaphorase inhibition with dicumarol injected unilaterally into the medial forebrain bundle (MFB) on monoamine and metabolite levels, alone, or following dopamine loading with 3,4-dihydroxyphenyl-L-alanine (L-DOPA) or MAO inhibition with L-deprenyl. Monoamine levels were assayed in aliquots from tissue samples from right and left striatum, including both dorsal and ventral regions. Dicumarol alone produced increases in 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA), but not in dopamine and metabolite levels when assayed two weeks later. However, following preloading with L-DOPA (3 x 25 mg/kg s.c. 7, 4 and 1 h before surgery), a long-lasting bilateral increase in dopamine and metabolite levels was observed after dicumarol. No effect was observed on dopamine, 5-HT and metabolite levels after L-deprenyl (3 x 10 mg/kg, s.c.) alone, but the levels were unilaterally increased when L-deprenyl was followed by dicumarol. The same result was produced when both L-deprenyl and dicumarol were injected simultaneously into the same brain region. In conclusion, the present study shows that intracerebral inhibition of DT-diaphorase produces long-term changes in 5-HT, but also in dopamine metabolism when DT-diaphorase inhibition is combined with MAO inhibition by systemic or intracerebral treatment with L-deprenyl. It is suggested that both MAO and DT-diaphorase have to be inhibited for inducing long-term changes in monoamine metabolism. Thus, DT-diaphorase is an enzyme to be taken into account when L-DOPA is used to treat Parkinson's disease, or when an MAO-inhibitor is used to treat depression.

Stroke as the first manifestation of calcific aortic stenosis

Heart valve calcifications are rarely recognized as a potential source for cerebral embolism. Previous studies have identified mitral, but not aortic, valve calcifications to be risk factors for stroke. Based on these studies, heart surgery is unlikely to be indicated in patients who present with a stroke and an 'incidental' aortic valve calcification. We report a case of a 46-year-old man presenting with acute onset of left-sided weakness and numbness. A previous smoking history was the only cardiovascular risk factor found. Head CT scan revealed a right middle cerebral artery territory infarct and an adjacent high-density lesion. CT angiography demonstrated the presence of calcific embolic material in the middle cerebral artery. A search for embolic sources revealed a calcific aortic stenosis (CAS). Initially placed on coumadin, the patient developed silent myocardial infarction 2 months later, presumed to be also embolic in origin from the CAS. After aortic valve replacement, the patient has been symptom-free during a 2-year follow-up. In conclusion, CT angiography may be the method of choice for detecting calcific cerebral emboli, and demonstration of a causal relationship between CAS and an embolic stroke by CT angiography may be an important adjunct in surgical decision-making.

La desesperacion: migrant and seasonal farm workers living with HIV/AIDS

Migrant seasonal farm workers (MSFWs) in south Texas are predominantly Mexican American and represent one of the most impoverished and medically underserved populations in the United States. La Frontera is a collaborative partnership between the University of Texas Health Science Center at San Antonio, migrant organizations, and HIV service delivery organizations to study and address special needs of MSFWs in Hidalgo and Maverick counties of south Texas. The purpose of this qualitative study is to explore the health-seeking experiences of HIV-positive MSFWs living in the La Frontera service area. Denzin's interpretive interactionism methodology guided the study. Thirteen participants were interviewed and audiotaped as they described their experiences. Findings from content analysis of the interviews revealed a description of the life of an HIV-positive MSFW as la desesperacion (a separate way of life). After their diagnosis of HIV/AIDS, the major themes in their lives were living in secrecy (a silent cry), finding and receiving health care, and accepting the disease (may it be the will of God).

Serum levels of 25-hydroxyvitamin D in a year of residence on the Antarctic continent

OBJECTIVE

Since exposure to sunlight is the main source of vitamin D in human beings and skin photosynthesis decreases markedly as the latitude increases, we studied the changes in serum 25-hydroxyvitamin D (25(OH)D) levels in young healthy men who lived in the Antarctic Continent during 1 year.

DESIGN

Blood was drawn in the fasting state every 2 months from March 1990 to January 1991 to determine the serum levels of calcium, alkaline phosphatase and 25(OH)D.

SUBJECTS

19 healthy volunteers, who left Buenos Aires (34 degrees S) during the 1990 summer, arriving at the Antarctic bases at the end of January (Belgrano) and in mid-March (San Martín) and stayed there up to summer 1991.

RESULTS

Serum calcium did not change significantly throughout the year. Serum alkaline phosphatase levels were not different comparing the beginning to the end of the year, but autumn and winter levels were lower (P < 0.05). At Belgrano Base the serum 25(OH)D levels (ng/ml) decreased from (mean +/- SD) 18.7 +/- 7.4 (March) to 10.0 +/- 4.3 (July) (P < 0.005) and did not recover for the rest of the year. At San Martín Base the serum 25(OH)D levels descended from 22.0 +/- 5.4 in March to 12.2 +/- 3.7 in August (P < 0.02) and did not increase even at the beginning of summer (January) except in two men with frequent outdoor activities.

CONCLUSIONS

The levels of 25(OH)D of healthy men living in the Antarctic continent decreased to approximately 46% of the initial values and did not increase even at the onset of summer. Further studies should determine the effect of these changes upon calcium-regulating hormones and bone metabolism.

Quantitative evaluation of anticonvulsant effects on penicillin-induced spike foci in cats

We evaluated the effects of phenytoin, carbamazepine, phenobarbital, sodium valproate, and ethosuximide on penicillin-induced spike foci. Phenytoin, carbamazepine, and phenobarbital at blood levels within or slightly above the human therapeutic range in humans increased spike frequency, decreased spike duration, and abolished after discharges. Ethosuximide and sodium valproate had no statistically significant effect even at blood levels considered toxic in humans. The experimental spike focus and the method of analysis appear useful for: (1) detection of new potentially anticonvulsant drugs, (2) classifying new potentially anticonvulsant drugs according to the type of clinical seizure for which benefit is most likely, and (3) comparing different anticonvulsant drugs.

Quantitative studies of spike foci induced by minimal concentrations of penicillin

The minimal concentrations of penicillin which induce stable recurrent spikes (20,000 U/ml) and which elicit stable recurrent after-discharges (100,000 U/ml) were determined. A quantitative study of the inter-relationships, variability and changes with time of a number of spike parameters (spike latency, spike amplitude, amplitude of prepositivity, spike duration and spike frequency) was performed. The study adds new information on the pathogenesis of the experimental spike focus and serves as baseline for quantitative evaluation of the effects of anticonvulsants on the characteristics of the primary spike focus and on after-discharges.

The effects of phenytoin on the penicillin-induced spike focus

A quantitative evaluation of the effects of phenytoin on penicillin-induced spike foci is reported. Phenytoin at blood levels considered within therapeutic range in humans increased spike frequency, decreased spike duration and abolished after-discharges. Spiking at weak foci was completely abolished when high concentrations of phenytoin were used. It is concluded that phenytoin affects mainly the long chain pathways whether the ultimate effects of these pathways are excitatory or inhibitory.