[Effectiveness of and tolerance to azithromycin versus roxithromycin in the treatment of patients with acute infections of the upper respiratory tract]

A multicenter open prospective comparative study was carried out during two years enrolling 60 patients with upper respiratory infections. Thirty were treated with single daily 500 mg doses of azithromycin for three days, and 30 received two daily doses of roxithromycin of 150 mg each for seven days. Both treatments were equally well tolerated, and there was no substantial difference concerning clinical recovery. However, azithromycin treatment was more practical and of shorter duration.

Non specific increased expression of class I major histocompatibility complex (MHC) antigens on rat liver grafts

Major histocompatibility complex (MHC) antigens play a major role in the rejection reaction and their increased expression may increase the host response to the foreign graft. Several clinical and experimental studies have demonstrated increased expression of MHC antigens on the different cell components of liver allografts during rejection. However modified expression of MHC antigens may also occur in certain liver diseases, after cholestasis or on a regenerating liver. In this experimental study in inbred rats, we compared the expression of MHC antigens on liver cells during rejection and non-immunological situations (cholestasis, cytolysis, regeneration).

Specific absorption of lymphocytotoxic alloantibodies by the liver in inbred rats

It has been suggested that liver allografts are less sensitive to lymphocytotoxic antibodies than other organ allografts. In this experimental study in sensitized inbred rat recipients, we have used extracorporeal liver hemoperfusion to study interactions between the liver and lymphocytotoxic antibodies. Donor-specific liver hemoperfusion can delay hyperacute rejection of heart allografts and reduce the level of lymphocytotoxic antibodies. Immunofluorescence examination of the hemoperfused liver revealed deposits of C3 on Kupffer cells and of IgG on sinusoidal cells. In control rats in which a third-party liver, a donor-specific splenic or renal hemoperfusion was performed, heart allograft survival was less prolonged. The decrease in antibody levels was not significant and the deposit of C3 and IgG was much less evident. Similarly, previous blockade of the Kupffer cells of the donor-specific hemoperfused liver by dextran sulfate suppressed the effect of liver hemoperfusion. These results support the hypothesis that resistance of the liver to hyperacute rejection might be due to a massive and nontoxic absorption of lymphocytotoxic antibodies onto nonparenchymal liver cells.

Delayed rejection of heart allografts after extracorporeal donor-specific liver hemoperfusion. Role of Kupffer cells

Liver allografts have a privileged status in regard to acute rejection. In this experimental study, we have analyzed the immunosuppressive effects of an extracorporeal liver hemoperfusion. In the LEW-to-BN combination of inbred rats, donor-specific liver hemoperfusion can significantly delay acute rejection of heart allografts. Analysis of the immunological status of these animals revealed a significant decrease in donor-specific lymphocytotoxic antibodies and in cytotoxic T lympholysis. Reactivity in mixed lymphocyte culture was normal. After third-party (DA) liver hemoperfusion or after donor-specific (LEW) splenic hemoperfusion, prolongation of heart allograft survival was moderate. Previous blockade of Kupffer cells suppressed the effects of donor-specific liver hemoperfusion. These results suggest that the sequestration by Kupffer cells of a clone of cytotoxic T cells and/or lymphocytotoxic antibodies may explain the immunosuppressive effects of donor-specific liver hemoperfusion.

A study of mitosis, meiosis, histology, and scanning electron microscopic details of spermatogenesis in an infertile male with probable 46,XY/47,XXY germinal mosaicism

A 29-year-old infertile man with mild eunuchoid body proportions and unilateral gynecomastia with a low sperm count had normal chromosomes in lymphocytes and skin fibroblasts. Serum testosterone, urinary ketosteroid, and follicle-stimulating hormone levels were normal, but serum prolactin, luteinizing hormone, and estrogen levels were above normal. Testicular biopsy showed hypocellularity, a pacuity of maturing sperm, and increased lipid content in early spermatogonia. Cytogenetic analysis of the testicular material showed probable 46,XY/47,XXY mosaicism in spermatogonial cells. None of the cells in diakinesis and metaphase I showed the extra-X as a univalent, and 50% of the cells in diakinesis were hypodiploid with intact XY bivalents. Further analysis of spermatogenesis revealed polymorphic dyads, triads, tetrads, and uncleaved meiotic products of first and second meiosis. Sex chromatin studies of testicular cells showed that 20% of the cells were X-chromatin positive. Scanning electron microscopic study of sperm revealed a wide range of polymorphisms, with some uncleaved meiotic products maturing into double-headed and double-tailed sperm or sperm with bulbous middle pieces or protrusions. A cytogenetic basis for the origin of these abnormalities is presented.

Cyproheptadine-induced remission of Cushing's disease

Experimental evidence suggests a central-nervous-system origin of Cushing's disease and a role for serotonin in the regulation of ACTH release. The efficacy of cyproheptadine therapy, therefore, was studied in three patients with such disease. Administration of 24 mg daily over a period of three to six months was associated with prompt and sustained clinical and laboratory remission. Lessening of the physical manifestations of hypercorticism occurred, together with marked improvement in muscular weakness. Urinary corticosteroid excretion and cortisol secretory rate returned to normal. The urinary corticosteroid response to dexamethasone (2 mg per day) became normal; a paradoxical increase followed 8 mg per day. Abnormal circadian periodicity of plasma cortisol concentrations persisted. Return of normal amounts of Stage III to IV sleep occurred in the one patient so studied, who previously had markedly decreased periods of these stages. Discontinuance of therapy in one patient was associated with return of laboratory evidence of hypercorticism.