Distribution and changing density of gamma-delta T cells in murine skin during the induced hair cycle

Summary Gamma-delta T cells (gdTC) are recognized as the predominant intraepidermal T-cell population in murine skin, although their physiological functions are still unclear. Little is known of the exact distribution of gdTC in the other epithelial skin compartments of normal mice. Using selective gdTC-receptor antibodies in immunohistology (alkaline phosphatase technique), the distribution and density of gdTC was analysed morphometrically in cryostat sections of full-thickness back skin of normal, adolescent C57 BL-6 mice in all the different stages of the depilation-induced hair cycle. We found that, during the entire hair cycle, V gamma 3-TCR-bearing lymphocytes are restricted to the epidermis, and to the epithelial hair bulb in, and distal to, the bulge area. No gdTC were seen in the sebaceous glands. During early anagen development, the number of pan-gdTC receptor-positive cells increased significantly ( P <0·005) in the interfollicular epidermis and the supainfundibular portion of the hair bulb, whereas the number decreased in the infrainfundibular region ( P ≤0.005). As gdTC are thought to migrate into the skin only during embryogenesis, this finding suggests hair cycle-dependent, differential intraepithelial proliferation of gdTC in murine skin. We advocate employing only skin of defined hair cycle stages in immunological studies on murine skin, and discuss the value of the C57 BL-6 model for assessing the functions of gdTC in skin and hair biology.     

Liposomal 1,25 (OH)2 vitamin D3 compounds block proliferation and induce differentiation in myelomonocytic leukaemia cells

The vitamin D₃ derived hormone 1,25 (OH)₂ vitamin D₃ (1,25 D₃) is able to induce growth arrest and differentiation in myelomonocytic leukaemia cells. In order to allow for specific delivery to leukaemic cells the lipophilic compound was incorporated into the lipid membranes of liposomes. Liposomal 1,25 D₃ reduced proliferation as measured by ³H-thymidine incorporation in HL60 leukaemia cells by up to 60%. When liposomes were prepared at different concentrations of 1,25 D₃ 65% inhibition was achieved at 48 n M . The MC 1288 stereoisomer of 1,25 D₃ was more potent and had the same activity at 48 n M .
The effect of the liposomal compounds was specific to myeloid cells as they reduced proliferation in myelomonocytic HL60, monoblastic U937 and monocytic Mono Mac 6 cells but not in the T-cell lines Jurkat and Molt 4.
The antiproliferative effect of liposomal 1,25 D₃ was associated with an induction of differentiation since treated HL60 cells showed a monocytic morphology, increased expression of CD14 and decreased expression of CD33.
When peripheral blood leukaemic cells from M4 and M5 acute myeloid leukaemia (AML) patients were admixed with liposomal compounds an antiproliferative effect was seen in all five cases, including the two cases where free compounds led to enhanced growth. Liposomal delivery of 1,25 (OH)₂ vitamin D₃ may offer a novel approach to treatment of myelomonocytic leukaemia.     

Kinetic Analysis of Interleukin 2 (IL-2) Production and Expression of IL-2 Receptors by Uraemic and Normal Lymphocytes

The in vitro immune response of lymphocytes from uraemic patients was studied by comparing the in vitro kinetics of interleukin 2 (IL-2) production, the mitogen-induced proliferative response, and the expression of IL-2 receptors by T lymphocytes. The IL-2 production in 26 uraemic cell cultures decreased significantly after 48 h of stimulation with mitogen compared with that of 24 control cultures. The lymphocyte responses to phytohaemagglutinin (PHA), concanavalin A (Con A), and pokeweed mitogen (PWM) increased linearly with time, but the responses of the uraemic cell cultures were significantly lower than those of the control cultures. The relative numbers of cells double-stained for both Tac (IL-2 receptor)/HLA-DR or Tac/Leu 2 were significantly increased in the uraemic cultures as compared with the control cultures at 48 and 72 h. A similar, but not significant, trend was also demonstrated for uraemic cells positive for Tac/Leu 3. These findings were also seen in uraemic lymphocyte cultures supplemented with exogenous IL-2. Thus, the IL-2 production of uraemic lymphocytes seems to be exhausted more rapidly than that of normal lymphocytes, and there is no evidence that the poor proliferative response of uraemic lymphocytes is due to a decreased relative number of cells positive for IL-2 receptors.     

Effect of the bile-acid sequestrant colestipol on postprandial serum bile-acid concentration: evaluation by bioluminescent enzymic analysis

Chronic ingestion of bile-acid sequestrants has been shown to decrease the serum cholesterol concentration and coronary events in hypercholesterolaemic patients. To develop improved sequestrants, a rapid, convenient method for testing the bile-acid binding efficacy of sequestrants is needed. Serum bile-acid concentrations could be used to detect bile-acid binding by an administered sequestrant, since the serum bile-acid concentration is determined largely by the rate of intestinal absorption in healthy individuals. To test this, serum bile-acid concentrations were measured at frequent intervals over 24 h in five otherwise healthy hypercholesterolaemic subjects during the ingestion of three standard meals, with or without the addition of 5 g colestipol granules administered 30 min before each meal. Total serum bile-acid concentration was measured with a previously reported bioluminescent enzymic assay, that uses a 3 alpha-hydroxysteroid dehydrogenase, an oxido-reductase, and a bacterial luciferase co-immobilized on to Sepharose beads. Bile acids in 1 ml of serum were isolated by solid-phase extraction chromatography with reversed-phase C18 cartridges. Colestipol lowered the postprandial elevation of serum bile acids by one half, with a subsequent decrease in the cumulative area under the curve. The data suggest that measurement of serum bile-acid concentrations by bioluminescence is a rapid, simple way to document the efficacy of bile-acid sequestrants.     

Long-term follow-up after intertrochanteric varus osteotomy for haemophilic arthropathy of the hip

In view of an increasing tendency in prosthetic management of haemophilic arthropathy, we intended to evaluate the efficacy of corrective osteotomy of the hip, specifically taking long-term clinical and radiographic results into consideration. Eleven hips affected by haemarthropathy in nine patients suffering from severe haemophilia A were treated with an intertrochanteric varus osteotomy. The average follow-up period was 15 small middle dot4 years. The preoperative clinical score of the Advisory Committee of the World Federation of Haemophilia was 5 small middle dot3 points (range 4-7) and the Pettersson score was 6 small middle dot4 points (range 2-10). The average WFH score at follow-up had increased to 3 small middle dot6 points. Seven hips showed clinical improvement, two hips showed a postoperative deterioration while a further two hips remained unchanged. The Petterson score increased to an average of 7 small middle dot7 points. Here the radiographs of six patients indicated postoperative deterioration, three remained unaltered and two showed improvement. Our study cannot conclusively answer whether intertrochanteric varus osteotomy for haemophilic arthropathy of the hip is always a feasible alternative to joint arthroplasty. The decision for or against this procedure must be individually assessed and the patient must be thoroughly informed about the advantages and disadvantages of both procedures.     

Safety of Transcatheter Aortic Valve Implantation in a Hospital With Visiting On‐Site Cardiac Surgery

Objectives

To describe the feasibility and safety of transcatheter aortic valve implantation (TAVI) with a visiting on‐site cardiac surgery program for surgical back‐up.

Background

Both European and American guidelines recommend institutional cardiac surgery back‐up for TAVI. However, the conversion to cardiac surgery is very rare, many complications of TAVI can be managed by catheter techniques and a visiting team can also provide surgical stand‐by. Therefore, the need for institutional cardiac surgery (by a surgeon who routinely performs conventional surgical valve replacement at the institution performing TAVI) has been questioned.

Methods

A retrospective review of consecutive TAVI cases with visiting on‐site cardiac surgery was performed. Key demographic, echocardiographic, and procedural data were collected prospectively.

Results

A total of 97 patients (81.9 ± 6.3 years) with high‐risk criteria (log Euroscore 21.6 ± 14.4, chronic renal failure 39.2%, severe systolic dysfunction 24.7%) underwent TAVI with visiting on‐site cardiac surgery at our institution. Local anesthesia with or without conscious sedation was used in 94.8% of patients. Procedural technical success was 100%, with 2 episodes of tamponade (both treated with pericardiocentesis) and a 16.5% vascular complication rate (all treated conservatively or percutaneously). Thirty‐day mortality was 3.1%, with 5.2% rate of stroke and 8.2% rate of major bleeding. There were no conversions to surgery.

Conclusions

TAVI can be done safely in the setting of a hospital with visiting on‐site cardiac surgery. This requires careful patient selection, experienced operators and surgeons in experienced centers with well‐established criteria and processes of care. In this setting, it may be an option for hospitals without institutional cardiac surgery. (J Interven Cardiol 2015;28:76–81)

     

The Immunodeficiency of Bone Marrow-Transplanted Patients

Lymphocytes from 21 patients sampled 1-6 months after bone marrow transplantation (BMT) were tested for functional suppressor activity against marrow-donor lymphocytes in the lymphocyte transformation test. Suppression of donor responses to allogeneic (i.e. mixed lymphocyte reaction, MLR) and antigenic stimulation by irradiated (7600 rad) post-BMT cells was observed in about two-thirds of the combinations tested (N = 20 and N = 9). The suppression of donor MLR and antigen responses ranged between 5-52% and 10-46%, respectively. Irradiated post-BMT cells significantly suppressed donor responses to suboptimal concentrations of phytohaemagglutinin (PHA) (median suppression: 28%; P less than 0.05; N = 7) and concanavalin A (Con A) (median suppression: 31%; P less than 0.05; N = 6). A clearly suppressive effect of post-BMT cells was observed when the ratios of CD4+/CD8+ post-BMT cells were lower than 0.5 (P less than 0.01). In three experiments, the depletion of the CD8- but not of the CD4-positive subset abrogated the suppression of the donor MLR by post-BMT cells. The suppression by post-BMT cells (irradiated) of MLR and mitogen responses was comparable whether the responding cells were derived from the donor or from HLA-DR-incompatible, unrelated individuals. The proliferative capacity of post-BMT cells compared to that of donor cells was assayed in the MLR with unrelated, HLA-DR-incompatible stimulator cells. A significantly decreased proliferative capacity (median 20% of that of donor cells) was found (P less than 0.01; N = 16). A weak inverse correlation (P less than 0.05; N = 16) between the proliferative and the suppressive capacity of post-BMT cells in the MLR was observed. These findings indicate that the decreased proliferative capacity upon mitogen, antigen, and alloantigen stimulation observed in most patients within 1-6 months after BMT may be partly due to non-specific suppression by CD8+ cells.     

Bowenoid lesions, Bowen''s disease and keratoacanthomas in long-term PUVA-treated patients

Four patients are described, two with histologically proven multiple foci of bowenoid lesions, one patient with bowenoid lesions and Bowen's disease, and one patient with two keratoacanthomas, most of the lesions occurring in non sun-exposed but photochemically treated areas of the body. These patients had received long-term PUVA treatment for their psoriasis. Two patients had a history of arsenic intake. The possible relationship of these epidermal lesions to light treatment is discussed.