Generation of a chimeric human and simian immunodeficiency virus infectious to monkey peripheral blood mononuclear cells.

We constructed five chimeric clones between human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus (SIVMAC) and four SIVMAC mutants by recombinant DNA techniques. Three chimeric clones and all mutants with an alteration in either the vif, vpx, vpr, or nef gene were infectious to human CD4-positive cell lines. The susceptibility of macaque monkey peripheral blood mononuclear cells (PBMC) to infection by these mutants and chimeras was examined in vitro. Macaque PBMC supported the replication of wild-type and vpx, vpr, and nef mutant SIVMAC strains. A chimera carrying the long terminal repeats (LTRs), gag, pol, vif, and vpx of SIVMAC and tat, rev, vpu, and env of HIV-1 was also replication competent in PBMC. In contrast, HIV-1, the vif mutant of SIVMAC, a chimera containing rev and env of SIVMAC, and a chimera containing vpx, vpr, tat, rev, and env of SIVMAC did not grow in PBMC. Western immunoblotting analysis of the replicating chimera in PBMC confirmed the hybrid nature of the virus. These data strongly suggested that the sequence important for macaque cell tropism lies within the LTR, gag, pol, and/or vif sequences of the SIVMAC genome.     

Clerodane diterpenoids from the roots of Portulaca pilosa

Three trans-clerodane diterpenoids, pilosanol A, B and C, the last compound being a glucoside, have been isolated from the roots of Portulaca pilosa. They show a marked contrast in skeletal type with the constituents of aerial part. Evolutionary changes in the biosynthetic abilities of Portulaca species is discussed.     

Microsurgical toenail transfer to the hand

Free nonvascularized toenail grafts have been used to reconstruct congenital or traumatic nail defects of the thumb or finger. Unfortunately, these transfers often result in deformity or atrophy. To avoid these undesirable results, microsurgical free vascularized toenail transfer was performed in 10 patients, 3 for congenital nail absence and 7 for traumatic nail defects. Patient age averaged 17 years (range 2 to 32 years). In contrast with previous reports, the whole big or second toenail complex without pulp was used in reconstruction. All 10 nails were successfully transferred with complete survival. No digits required reexploration. There were no donor- or recipient-site problems. Follow-up averaged 3 years, with a range of 14 months to 5 years and 4 months. Appropriate nail growth occurred in the congenital patients. No atrophy of the nail complex was found as long as sufficient bony support was present (9 of 10 cases). Whole free vascularized toenail transfers for reconstruction of congenital and traumatic nailbed defects achieve excellent aesthetic results while maintaining normal hand function.     

Sensitive detection of viral antigens with a new method, "laser magnet immunoassay".

A new method, "laser magnet immunoassay" (LMIA), has been developed for sensitive detection of viral antigens. Target viruses captured on microbeads were made to react with antibodies labeled with magnetite particles. In a magnetic field, magnetically labeled antigens dispersed in water were attracted to and concentrated at one point on the surface, resulting in the lifting up of a small surface area. A laser beam which was incident on the point reflected, making an interference fringe. The intensity of the fringe indicates the amount of the magnetite conjugated with antigen. A very low concentration of antigens, such as 5 particles of influenza virus and 0.1 pg/ml of human immunodeficiency virus (HIV) p24 antigen in human serum, could be detected by this method. Application of this method to diagnoses of viral diseases in early stages is discussed.     

Chondrosarcoma of the trachea. A case report and literature review

The cytologic presentation of a case of chondrosarcoma of the trachea in a 72-year-old man is described. A mass detected on routine chest roentgenogram and defined by CT scan was used to make a touch imprint smear during partial tumor resection. The cytologic findings included round or polygonal cells with occasional binucleation, round hyperchromatic nuclei and prominent nucleoli, present in an amorphous pink-violet or light-blue background containing fragments of chondroid tissue. The histopathology was interpreted as a low-grade chondrosarcoma. Cartilaginous tumors of the trachea should be considered in the differential diagnosis of upper airway obstruction.     

High propeller twist and unusual hydrogen bonding patterns from the MD simulation of (dG)6.(dC)6

A molecular dynamics (MD) study of (dG)6.(dC)6 including counter ions and 292 water molecules was made. The hydrogen bonding pattern and propeller twist angles for the mini-helix are reported as averages for times spanning 21-30, 31-40, 41-50, and 51-60 ps. The propeller twist angles range from 18 degrees to 38 degrees. Bifurcated and interstrand neighboring base (twisted) hydrogen bonding patterns were found.     

Phospholipase A2 in macrophage plasma membrane releases arachidonic acid from phosphatidylinositol

A high level of arachidonic acid release from [2-14C]arachidonylphosphatidylinositol (PI) was observed at neutral pH (6.0-7.0) in the presence of purified plasma membranes of guinea pig peritoneal macrophages. This activity was at least 10-fold higher than that with arachidonylphosphatidylcholine (PC) or phosphatidylethanolamine (PE) as substrate. The accumulation of [14C]diacylglycerol and [14C]phosphatidic acid was not detected at any time, and arachidonic acid release from [14C]arachidonyldiacylglycerol was not detectable either. The data suggest that arachidonic acid release from PI may not occur via the phospholipase C pathway. In this paper, we demonstrate the possibility that arachidonic acid release from PI at neutral pH in the macrophage plasma membrane is dependent on the action of phospholipase A2 (EC 3.1.1.4) -like activity. The maximum arachidonic acid release was dependent upon both pH and substrate. Particularly, the activity of arachidonic acid release from PI at neutral pH was very high compared with that from PC or PE. We suggest that phosphatidylinositol phospholipase A2 (EC 3.1.1.52) may play an important role in providing arachidonic acid for subsequent metabolic activity in the macrophages.     

Alpha-interferon treatment for adult T cell leukemia: low levels of circulating alpha-interferon and it's clinical effectiveness

We describe a patient with adult T cell Leukemia to whom alpha-interferon therapy was highly effective. Although a combination chemotherapy (ACVP) first introduced was effective in reducing total leukocyte counts, the percentage of leukemic cells relative to total leukocyte counts was decreased first after the institution of alpha-interferon therapy. The patient is now under complete remission for four years. It was noted in this patient that circulating alpha-interferon, measured by a sensitive radioimmunoassay, was consistently low as compared with the value found in the age-, sex-matched healthy control (p less than 0.001). Since adult T cell leukemia is pathogenetically related to the retrovirus infection, low levels of circulating alpha-interferon of the patient may be important from both pathogenetic and therapeutic standpoints. Alpha-interferon therapy may be an useful additive for the chemotherapy of adult T cell leukemia.     

Preparation and properties of the water-soluble chlorophyll-bovine serum albumin complexes

By mixing chlorophyll (Chl) a or b with a dense bovine serum albumin solution, the water-soluble Chl-bovine serum albumin complexes were prepared. These complexes, eluted near the void volume on a gel filtration, were separated well from unreacted bovine serum albumin, indicating an aggregation of such molecules in the complexes. Preparation of chlorophyllide (Chlide) a- or Chlide b-bovine serum albumin complex was unsuccessful, while the phytol-, and β-carotene-bovine serum albumin complexes could be obtained. Chls in the Chl-bovine serum albumin complexes had the following characteristics. (i) Main absorption peak of Chl a or b in the red region occurred at 675 nm or 652 nm, respectively. The Chl a-bovine serum albumin complex having absorption peak at 740 nm was also prepared. As compared with the stabilities of Chl a and b in Triton X-100. (ii) Both Chls in the bovine serum albumin-complexes were stable against oxidative stresses, such as photobleaching, Fenton reagent, peroxidase-H₂O₂ system. But (iii) they were easily hydrolyzed by chlorophyllase. These properties of Chls in the bovine serum albumin-complexes were similar to those of Chls in the isolated light-harvesting Chl a/b protein complex. A possible localization of Chls within the bovine serum albumin complexes was suggested that the porphyrin moiety of Chl was buried in bovine serum albumin; however, the hydrophilic edge of porphyrin ring, adjacent to the phytol group, occurred in the hydrophilic region of a bovine serum albumin molecule.     

Effect of Ca2+ channel antagonists on the acrosome reaction of guinea pig and golden hamster spermatozoa

The effects of Ca²⁺ channel antagonists on the motility and acrosome reaction of guinea pig spermatozoa were examined by incubating the spermatozoa continuously in Ca²⁺-containing capacitating media with 10^?6 M to 10^?4 M antagonist. Antagonists tested were four voltage-gated Ca²⁺ channel antagonists (verapamil, nifedipine, nimodipine, and FR–34235) and two ligand-gated channel antagonists (NaNO₂ and Na-nitroprusside). None of these antagonists could block the acrosome reaction. Instead, three antagonists (verapamil, nimodipine, and FR-34235, each at 10^?4 M) accelerated the onset of the acrosome reaction with a subsequent decrease in sperm motility. Nifedipine and Na-nitroprusside at the same concentration caused a complete loss of sperm motility by 4 hr of incubation with no substantial effect on the rate of acrosome reaction. The detrimental effect of antagonists on the motility of spermatozoa appears to be due to a direct, Ca²⁺-independent, membrane-perturbing action of the reagents. The acrosome reaction was not inhibited when guinea pig spermatozoa were precapacitated in Ca²⁺-free medium (with a low concentration of lysolecithin) in the continuous presence of antagonists. An acceleration of the onset of the acrosome reaction by verapamil (10^?4 M) was also demonstrated in the golden hamster. These results may be interpreted as indicating that the entry of extracellular Ca²⁺ into spermatozoa, which triggers the acrosome reaction of guinea pig and hamster spermatozoa, is not mediated by Ca²⁺ channels. This is in marked contrast with the case reported in invertebrate spermatozoa. Possible mechanisms by which some of the antagonists stimulate the acrosome reaction and affect the motility of mammalian spermatozoa are discussed.