[Clinical effects of superficial temporal artery lobulated perforator flaps in repairing skin and soft tissue defects after temporal tumor resection].

Objective: To explore the feasibility and clinical effects of using superficial temporal artery lobulated perforator flaps in repairing skin and soft tissue defects after tumor resection in the temporal region. Methods: A retrospective observational study method was used. From March 2017 to October 2022, ten patients with temporal skin tumors were admitted to the Affiliated Hospital of Zunyi Medical University, including six women and four men, with age ranging from 42 to 87 years. Among them, three patients had squamous cell carcinoma and seven patients had basal cell carcinoma, with disease duration ranging from 6 months to 5 years. All temporal tumors underwent expanded resection, leaving wound areas of 5.4 cm×4.2 cm to 7.0 cm×4.0 cm after tumor resection. Superficial temporal artery frontal branch flaps with areas of 5.5 cm×1.2 cm to 7.0 cm×1.5 cm, superficial temporal artery descending branch flaps with areas of 4.2 cm×3.5 cm to 5.0 cm×4.0 cm, and superficial temporal artery parietal branch flaps with areas of 4.2 cm×1.0 cm to 5.0 cm×1.0 cm were designed to repair the wounds and reconstruct the hairline. The donor areas of the flaps were closed and sutured directly. The survival of the flaps was observed on 3 to 5 days after surgery, and the healing of wounds on the donor and recipient sites was observed when the stitches were removed on 5 to 7 days after surgery. During follow-up after surgery, the appearance of the temporal area, scar hyperplasia, hairline reconstruction, and tumor recurrence were observed in the temporal region on the affected side. Results: All the flaps survived well on 3 to 5 days after surgery, and all the donor and recipient site wounds healed well on 5 to 7 days after surgery. During follow-up of 3 to 6 months after surgery, the surgical incisions were concealed; the flaps were not swollen, with a consistent color to the surrounding skin; there were no obvious hypertrophic scars; the reconstructed hairline on the affected side was not significantly different from that of the healthy side; there was no tumor recurrence in the local area. Conclusions: For large areas of skin and soft tissue defects in the temporal region, the use of superficial temporal artery lobulated perforator flaps can repair the wounds in different regions and suture the donor sites in the primary stage simultaneously. The surgical operation is simple, and the facial appearance conforms to the aesthetic requirement after surgery with no tumor recurrence in the local area but a good repair effect. This method is particularly suitable for repairing large areas of skin and soft tissue defects in the temporal region in elderly patients.

Intramitochondrial functions regulate nonmitochondrial citrate synthase (CIT2) expression in Saccharomyces cerevisiae.

We have examined the effects of perturbation of mitochondrial function on expression of two nuclear genes encoding the mitochondrial and peroxisomal forms of citrate synthase in Saccharomyces cerevisiae, CIT1 and CIT2. CIT2 expression was as much as 30-fold higher in [rho0] petites, than in isochromosomal [rho+] cells, whereas CIT1 expression was slightly down regulated in [rho0] cells. CIT2 expression was also increased in [rho+] cells by inhibition of respiration with antimycin A or in [rho+] cells containing a disruption of the CIT1 gene. These effects were additive, and together they approached the level of CIT2 expression seen in [rho0] cells. Experiments using heterologous gene fusions showed that all of the effects leading to increased expression of CIT2 were transcriptionally controlled through 5'-flanking CIT2 DNA sequences. Analysis of [rho+] and [rho0] cells containing disruptions of CIT1 and CIT2, singly and in combination, showed that the peroxisomal citrate synthase could partially spare the mitochondrial isoform for growth yield in [rho+] but not in [rho0] cells. These studies suggest a physiological role for increased expression of CIT2 in cells with altered mitochondrial function. They also provide additional evidence for a retrograde path of communication from mitochondria to the nucleus in yeast cells.

Functional expression of a yeast mitochondrial intron-encoded protein requires RNA processing at a conserved dodecamer sequence at the 3' end of the gene.

All mRNAs of yeast mitochondria are processed at their 3' ends within a conserved dodecamer sequence, 5'-AAUAAUAUUCUU-3'. A dominant nuclear suppressor, SUV3-I, was previously isolated because it suppresses a dodecamer deletion at the 3' end of the var1 gene. We have tested the effects of SUV3-1 on a mutant containing two adjacent transversions within a dodecamer at the 3' end of fit1, a gene located within the 1,143-base-pair intron of the 21S rRNA gene, whose product is a site-specific endonuclease required in crosses for the quantitative transmission of that intron to 21S alleles that lack it. The fit1 dodecamer mutations blocked both intron transmission and dodecamer cleavage, neither of which was suppressed by SUV3-1 when present in heterozygous or homozygous configurations. Unexpectedly, we found that SUV3-1 completely blocked cleavage of the wild-type fit1 dodecamer and, in SUV3-1 homozygous crosses, intron conversion. In addition, SUV3-1 resulted in at least a 40-fold increase in the amount of excised intron accumulated. Genetic analysis showed that these phenotypes resulted from the same mutation. We conclude that cleavage of a wild-type dodecamer sequence at the 3' end of the fit1 gene is essential for fit1 expression.

In vitro and in vivo susceptibility of human leukemic cells to lymphokine activated killer activity.

The susceptibility of human myeloid and lymphoid leukemic blasts to the lytic action of recombinant interleukin-2 (rIL-2)-generated lymphokine activated killer (LAK) cells was analyzed. With the exception of the K562 cell line, all 9 leukemic cell lines tested were resistant to the natural killer activity of freshly isolated peripheral blood lymphocytes (PBL) from healthy donors but were susceptible to the lytic action of PBL cultured for 3 days in the presence of rIL-2. Of the 32 primary myeloid and lymphoid acute leukemia samples investigated, the great majority were natural killer cell-resistant but were variably sensitive to LAK effectors. Variations in LAK activity were observed according to the donor of PBL, while little or no difference was documented in the capacity to elicit LAK activity of PBL cultured with 100 or 1,000 U of rIL-2/ml. Pretreatment of the leukemic target cells with neuraminidase did not increase substantially their sensitivity to LAK activity. LAK cells generated from the PBL of patients at the onset of the disease or in complete clinicohematological remission lysed Raji cells as efficiently as normal LAK effectors. Finally, LAK cells were capable of abrogating the tumor growth in nude mice of a human leukemic T cell line. These findings demonstrate the susceptibility in vitro and in vivo of human leukemic blasts to the lytic effect of LAK cells and point to a possible clinical exploitment of this new form of adoptive immunotherapy in the management of acute leukemia.

Lymphokine activated killer (LAK) activity in lymphoproliferative disorders.

Lymphokine activated killer (LAK) cells are being considered as a new and promising form of immunotherapy in the management of patients with solid tumours. Few informations are instead available on these cytotoxic effectors in haematological neoplasias. Here we shall discuss the possible role of LAK cells in human leukaemias. Evidence will be provided for a rationale in the clinical exploitment of Interleukin 2 (IL2)/LAK cells in the treatment of acute leukaemia patients, whilst the implication of these cytotoxic populations appears more uncertain in chronic lymphoproliferative disorders.

Lymphokine Activated Killer (LAK) Cells Inhibit the in vitro Growth of Myeloid and Erythroid Progenitor Cells Via the Release of Tumor Necrosis Factor-Alphadagger.

Adoptive immunotherapy with lymphokine-activated killer (LAK) cells induced by Interleukin 2 (IL2) has provided a new and promising strategy for the treatment of cancer patients. The clinical observation of variable degrees of cytopenia(s) in patients with solid tumors treated with LAK cells suggests that IL2-activated effector cells may play a role on the normal progenitor cell compartment. We therefore carried out in vitro studies designed to assess the influence of LAK cells on normal hemopoiesis. LAK cells from different individuals were cultured with enriched normal peripheral blood and bone marrow colony-forming cells at effector: target ratios ranging between 1:1 and 10:1. Both LAK effectors generated from peripheral blood mononuclear non-adherent cells (PBL-LAK) and from sheep erythrocyte rosette-forming cells (RFC-LAK) suppressed in a reproducible manner the growth of CFU-GM and CFU-E from both peripheral blood and bone marrow. This inhibitory effect is dose-dependent, appears to be smaller with LAK cells generated from RFC rather than from unfractionated PBL and is less evident on the early erythroid compartment. In general, the effect is more pronounced when LAK cells are pre-incubated for 18 hours with the target cell populations prior to seeding. Both autologous and allogeneic PBL-LAK inhibit colony formation. The mechanism of killing implicates a release of soluble factor(s) after close cell-to-cell interaction, as only cell-free supernatants produced after pre-incubation of PBL-LAK cells with hemopoietic progenitors give rise to inhibitory effects. The evidence that during this incubation time high levels of Tumor Necrosis Factor-alpha (TNF) are released and that the use of an anti-TNF antibody completely abolishes the inhibitory effect suggests that TNF plays a part in the LAK cell-induced inhibitory activity.

Lymphokine-activated killer (LAK) cells inhibit the clonogenic growth of human leukemic stem cells.

The effect of lymphokine-activated killer (LAK) cells on the in vitro clonogenic capacity of acute myeloid leukemia (AML) blasts was investigated in a semisolid medium assay. The leukemic clonogenic capacity of 11 AML cases, selected on the basis of their ability to grow in vitro, was highly reduced following overnight preincubation with LAK effectors. The degree of colony inhibition, which ranged between 66% and 98% (mean 83.8% +/- 11.4 SD), was quantitatively greater than by 51Cr release, which gave rise to lytic values between 5% and 65% (mean 43.2% +/- 19.2 SD). The demonstration that the clonogenic inhibition was still induced following a shorter pre-incubation period (4 hours) suggests that the effect is unlikely to be due only to the generation of cytotoxic activity during the incubation time. The possibility that LAK cells may be employed in the management of residual disease is strengthened by the evidence that the clonogenic potential of samples containing as few as 20% and 14.3% leukemic cells could be almost completely abolished by LAK effectors. These findings further point the possible role of adoptive immunotherapy with interleukin 2/LAK cells in the treatment of patients with acute leukemia.