The isolation of cDNAs from OATL1 at Xp 11.2 using a 480-kb YAC

Using an ornithine-delta-aminotransferase (OAT) cDNA, we identified five YACs that cover two nonadjacent OAT-related loci in Xp11.2-p11.3, designated OATL1 (distal) and OATL2 (proximal). Because several retinal degenerative disorders map to this region, we used YAC2 (480 kb), which covers the most distal part of OATL1, as a probe to screen a retinal cDNA library. From 8 x 10(4) plaques screened, we isolated 13 clones. Two were OAT cDNAs. The remaining 11 were divided into eight groups by cross-hybridization. Groups 1-4 contain cDNAs that originate from single-copy X-linked genes in YAC2. Each has an open reading frame of > 500 bp and detects one or more transcripts on a Northern blot. The gene for each was sublocalized and ordered in YAC2. The cDNAs in groups 5-8 contained two or more Alu sequences, had no open reading frames, and did not detect transcripts. The cDNAs from groups 1-4 provide expressed sequence tags and identify candidate genes for the genetic disorders that map to this region.

Localization of the 70-kDa peroxisomal membrane protein to human 1p21-p22 and mouse 3

The 70-kDa peroxisomal membrane protein (PXMP1) is a member of the ATP-binding cassette transporter family. In humans, mutations in this gene may be responsible for a subset of patients with Zellweger syndrome, a lethal inborn error of peroxisome assembly. The PXMP1 gene was assigned to human chromosome 1p21-p22 by in situ hybridization and its murine homologue (Pxmp-1) to chromosome 3 by interspecific backcross analysis.

Comparative cytogenetic analysis between cyclophosphamide-sensitive and -resistant lines of acute myeloid leukemia in the Lewis Brown Norway hybrid rat

An animal model of acute myeloid leukemia (AML) has been developed in the Brown Norway (BN) rat and has successfully been introduced into the Lewis x BN F1 hybrid (LBN) and designated LBN AML. The original LBN AML is sensitive to the chemotherapeutic agent cyclophosphamide (CY). Recently, a CY-resistant cell line of LBN AML has been established. To characterize this animal model of human leukemia better, we analyzed and compared the chromosomal makeup of both the CY-sensitive and CY-resistant LBN AML lines. The CY-sensitive LBN AML cultures contained two cell lines--line I (88%): 41,XX,-1,-2,-9,del(12)(q16), + der(1)t(1;?8)(p13;q31), + der(2)t(2;9)(p11;q11); and line II (12%): 41,XX,-1,-2,-9,del(12),del(20)(q13) + der(1)t(1;?8)(p13;q31), + der(2)t(2;9)(p11;q11). The recently developed CY-resistant AML cells contained two cell lines--line I (88%): 41,XX,-1,-2,-9,del(3)(q36q42.1),del(4) (q42.2),?t(5;?)(q35;?),?t(8;?)(q24;?),del(12)(q16), + der(1)t(1;?8)(p13;q31), + der(2)t(2;9)(p11;q11); and line II (12%): 42,XX (probably represents host contamination). The new chromosomal aberrations in the CY-resistant line I [del(3)(q36q42.1),del(4)(q42.2),?t(5;?)(q35;?), and ?t(8;?)(q24;?)] suggest a possible interrelationship between these secondary karyotypic abnormalities and acquisition of resistance to the chemotherapeutic agent.

Profiles of difficult psychiatric hospital patients

In a study of 127 long-term psychiatric hospital patients perceived as difficult to treat, investigators used hierarchical grouping analysis to differentiate ten profile groups of patients. The groups are based on four dimensions or clusters of characteristics previously derived by factor analysis: withdrawn psychoticism, severe character pathology, suicidal-depressed behavior, and violence-agitation. The ten profile groups are described and are related to staff ratings of overall treatment difficulty, prognosis, sex, diagnosis, and other variables. The main conclusion is that treatment difficulty stems in large part from the compounding of different dimensions of severe psychopathology. Thus a pan-symptomatic group, with high scores on all four dimensions, ranks highest in overall treatment difficulty.

High calcium intake does not prevent stress-salt hypertension in dogs

Avoidance conditioning sessions and isotonic saline (1.3 L/day) were administered to dogs for 12 days under conditions of a low (0.1%) or high (1.5%) calcium diet. Twenty-four-hour mean arterial pressure increased comparably during the stress-salt conditioning periods on both the low (systolic: +16 +/- 5 mm Hg; diastolic: +6 +/- 2 mm Hg) and high (systolic: +17 +/- 4 mm Hg; diastolic: +11 +/- 4 mm Hg) calcium diets. Urine volume, sodium excretion, and serum calcium levels on the high calcium diet were not significantly different from those on the low calcium diet. In a second experiment, calcium was infused continuously for six days into the arterial circulation of normotensive or stress-salt hypertensive dogs at a rate of 0.12-0.23 mEq/min. Although serum calcium levels increased by up to 50% under these conditions, there were no significant effects on 24-hour levels of arterial pressure. In contrast to the protective effect of augmented potassium intake, these findings indicate that calcium intake does not influence the development of stress-salt hypertension in dogs.

Patterns of staff perception of difficult patients in a long-term psychiatric hospital

In a study to determine which psychiatric patients are perceived by staff as most difficult to treat, clinical staff from several disciplines rated problem behaviors of 127 long-term inpatients in a private psychiatric hospital; staff also rated overall treatment difficulty, progress, and prognosis. No single patient characteristic determined staff's perception of patients as difficult to treat. Instead, four clusters of patient characteristics contributed to this perception; in decreasing order of influence, they are withdrawn psychoticism, severe character pathology, suicidal-depressed behavior, and violence-agitation. The study also showed that the patients who are considered particularly difficult are perceived as improving less and as having a poor prognosis.