Less-invasive sublabial unilateral transseptal approach for transsphenoidal surgery

A less-invasive sublabial approach was developed to overcome the disadvantages associated with the conventional sublabial approach. The basic differences between this modified sublabial approach and the conventional approach are: a smaller incision (1-1.5 cm long) and almost midline vertical skin incision underneath the upper lip; minimal development of an inferior tunnel; no widening of the maxillary rim of the piriform aperture; and a strictly unilateral approach. This less-invasive approach uses a slim and small nasal speculum originally designed for the transnasal approach. This modified sublabial approach was applied to 41 of 133 patients who underwent transsphenoidal surgery between August 1998 and the end of 2000. These cases confirmed that this approach is a simple, rapid, and less-invasive technique with significantly fewer mucosal complications compared to the conventional approach. We conclude that this modified sublabial approach offers a good alternative to the conventional standard sublabial approach.     

The clinical significance of follow-up sonography in the detection of cervical lymph node metastases in patients with stage I or II squamous cell carcinoma of the tongue

OBJECTIVE: We sought to assess the reliability of repeated sonography in the detection of cervical lymph node metastases at the earliest stage during a follow-up period in patients with stage I or stage II carcinoma of the tongue. STUDY DESIGN: Eighteen consecutive patients with stage I or II squamous cell carcinoma of the tongue were included. When possible, every patient was examined with sonography approximately every 2 weeks during the follow-up period. RESULTS: With repeated sonography on 18 patients, 7 metastatic nodes of 7 patients (39%) meeting our criteria were found. With the use of computed tomography, we diagnosed 10 nodes (including the 7 nodes observed with sonography) in these 7 patients as metastatic. A histopathologic examination revealed that 12 nodes in the same 7 patients had metastatic foci. For sonography, the sensitivity per node was 58%, whereas that of computed tomography was 83%. CONCLUSIONS: Follow-up sonography enabled the detection of all patients who had subsequent subclinical lymph node metastases. However, the sensitivity of sonography in the detection of smaller metastatic nodes was lower than that of computed tomography.     

Cerebral blood flow and vasodilatory capacity in anemia secondary to chronic renal failure

BACKGROUND: Our previous study reported that cerebral oxygen extraction fraction (OEF) increased in hemodialysis patients with anemia. The increased OEF suggests that the cerebral vasodilatory capacity might be impaired in these patients. To clarify this issue, we measured the CO2 response in patients with anemia secondary to chronic renal failure (CRF) using positron emission tomography (PET). METHODS: Ten anemic patients with CRF (6 females and 4 males) and 6 age-matched normal controls were studied. The underlying diseases of CRF were glomerulonephritis in 8 patients, systemic lupus erythematosus (SLE) in one patient, and hypertension in one patient; in this cohort, 5 patients were on hemodialysis treatment and the remaining 5 patients were in a pre-hemodialysis state. The cerebral blood flow (CBF) was measured by the O-15 H2O bolus injection method with each patient in a resting state and during 5% CO2 inhalation. The CO2 response was estimated as the percentage change of CBF per 1 mm Hg change of PaCO2. RESULTS: The CO2 response was significantly attenuated in anemic patients with CRF in comparison to the normal controls, and it inversely correlated with the severity of anemia. There was no significant difference in the CO2 response between the hemodialysis and pre-hemodialysis patients. The CO2 response significantly correlated with CBF and the cerebral metabolic rate for oxygen (CMRO2) at rest, however, it did not correlate with OEF and cerebral blood volume (CBV). CONCLUSIONS: The present study revealed the existence of a reduced cerebral vasodilatory capacity in anemic patients with CRF, suggesting that chronic hypoxic brain damage might play a role in the impaired cerebrovascular response to CO2.     

CT and MR features of nasopharyngeal carcinoma in children and young adults

AIM: To clarify CT and MR features of nasopharyngeal carcinoma (NPC) in children and young adults. METHOD: CT and MR findings of 13 patients (30 years old or younger) with a histopathologic diagnosis of NPC were reviewed. RESULTS: Skull base invasion (12/13), lymphadenopathy (10/13), and infiltrative growth (8/8) were common findings. The signal intensity of tumours was slightly higher than that of muscles in six cases and isointense to that of muscles in two cases on T1-weighted images; it was higher than that of muscle and lower than that of cerebellar grey matter on T2-weighted images in all cases. Internal signals were homogeneous in both pre- and post-Gd-enhanced MR images in all cases. CONCLUSIONS: Despite its rarity in this age group, NPC should be included in a differential diagnosis when CT and MR imaging reveal these features.     

New approach for generation of neutralizing antibody against human T-cell leukaemia virus type-I (HTLV-I) using phage clones

We have screened a phage peptide library to address whether clones binding to a monoclonal antibody (mAb) could be isolated and if the selected phage particles would be able to elicit an in vivo immune response against the original antigen. A phage peptide library, consisting of seven random amino acids inserted in the minor coat protein (pIII), was screened for specific binding to a rat mAb LAT-27, which is capable of neutralizing human T-cell leukaemia virus type-I (HTLV-I) by binding to its envelope gp46 epitope, (amino acids LPHSNL). Total 37 clones were selected from the library and one clone named 4-2-22 was tested for its immunogenicity in three rabbits. The all rabbit immune sera showed strong binding activity to a gp46 peptide carrying the neutralization sequence, stained gp46-expressing cells and neutralized HTLV-I in vitro as determined by cell fusion inhibition assay. These results show that the selected phage clone was capable of mimicking the epitope recognized by a HTLV-I neutralizing mAb, and it can be used as an immunogen to induce protective immune response against HTLV-I. Thus, the present methodology could be one of the approaches to develop vaccines against infectious agents in a simple and inexpensive way.     

Retroviral-mediated IL-12 gene transduction into human CD34+ cell-derived dendritic cells

Genetically modified dendritic cells (DCs) with Th1 type cytokine genes are useful for activating anti-tumor immune response. We made human interleukin (IL)-12 p70 gene-transduced DCs generated from CD34+ progenitor cells using a retrovirus system and investigated the function of IL-12-producing DCs. We used the pMX retroviral vector and made cytokine gene-containing viral vectors referred to as GFP pMX and hIL-12 pMX. Supernatants from BOSC23 cells transfected with GFP pMX and hIL-12 pMX were harvested and used for transfection of DC. Cord blood CD34+ cells were incubated with supernatants containing retrovirus for 48 h with cytokines such as IL-3, IL-6, SCF, Flt3 ligand (FL), bFGF and IGF-I. The cells were cultured for 12 days in the presence of GM-CSF, SCF, FL, IL-4 and TNF-alpha to get mature DC-enriched population. Analysis of surface marker on DCs and allogeneic MLR assay were also performed. After a 14-day culture, 60-70% of cultured CD34+ cells were DC marker (CD1a, DEC205) positive. The IL-12 p70 protein levels in supernatant of DC-GFP and DC-hIL-12 were 0.2 ng/ml and 53 ng/ml/5 x 10(5) DCs for 72 h, respectively. The addition of CH296 fibronectin fragment (FN) increased 3-fold IL-12 gene transduction efficiency into DCs. MLR assay showed that IL-12-producing DC exhibited more potent T cell growth-stimulating activity compared with GFP-DC. These results suggested that genetically modified CD34+ cell-derived DCs with human IL-12 gene are fully efficient in T cell priming, and could be a good tool for effective cancer immunotherapy.