Histochemical studies on hyaluronic acid in the developing human retina

Changes in the distribution of hyaluronic acid in the developing human retina were investigated histochemically with alcian blue staining and theStreptomyces hyaluronidase digestion method using 56 human embryos and fetuses ranging from 5 to 41 weeks of gestational age. Hyaluronic acid was first detected in the inner layer of the retina at 12 weeks. The site of accumulation extended towards the outer layer by 20 weeks. At the neonatal stage, longitudinal fibers, possibly the processes of Müller cells, were proved to contain hyaluronic acid. These findings suggest that Müller cells produce hyaluronic acid transiently from 12 weeks’ gestation to the neonatal stage.     

Gyrate atrophy of the choroid and retina: 15 Japanese patients.

We examined 15 Japanese patients who had gyrate atrophy of the choroid and retina with hyperornithinaemia. Their visual acuities fell to 0.2 or worse in the second or third decade of life. Myopia developed late in the first decade, and the refractions decreased to -10 or -15 dioptres at age 20. Tunnel vision developed at approximately age 20. Our results suggested that the visual functions of Japanese patients were worse in the third decade or later than similarly affected Finnish patients.     

Clinical analysis of ureteral tumours with or without renal pelvic neoplasms

Twelve patients with ureteral tumours with or without ipsilateral renal pelvic neoplasms were retrospectively analysed. Haematuria was the most common symptom. Location of all tumours was preoperatively detected by conventional diagnostic methods, such as intravenous or retrograde pyelography, washing cytology of the upper urinary tract, computed tomography, echogram and abdominal aortography. Cumulative proportion survivals of 1, 3 and 5 years were 81.9%, 68.2% and 45.5%, respectively. Patients with high Karnovsky rating survived longer (p<0.05) than those with low rating. Patients with low-stage tumours (T₁, T₂) showed longer survival rate (p<0.001) than those with high-stage tumours (T₃, T₄). Vascular invasion of tumour cells was present in removed specimens in 4 out of 7 patients who died or are alive with cancer, but none in those who survived without disease. Good therapeutic response could not be achieved unless surgery was performed.     

An orthodontic-orthognathic patient with obstructive sleep apnea treated with Le Fort I osteotomy advancement and alar cinch suture combined with a muco-musculo-periosteal V-Y closure to minimize nose deformity

In some severe skeletal Class III patients, mandibular setback surgery using sagittal split ramus osteotomy (SSRO) is performed to correct mandibular protrusion. However, in patients diagnosed with obstructive sleep apnea syndrome (OSAS), the risk of OSAS worsening as a result of the SSRO is very high. Maxillary advancement could reduce the degree of mandibular retropositioning and expand the skeletal framework in the pharyngeal region, leading to enlargement of the airway. However, nasal deformity is an undesirable outcome of the procedure. This case report describes a 23-year-old man with a retruded maxilla and OSAS. The maxillary retrusion was treated using Le Fort I osteotomy with an alar cinch suture and a muco-musculo-periosteal V-Y closure (ACVY). After treatment, better occlusal relationships and improvement in OSAS were observed. Thus, an ACVY could minimize nasolabial deformity.     

Morphological study on glycosaminoglycans in the developing human vitreous

The vascular and the avascular vitreous in 7th- and 8th-week human embryos and 9th-week fetuses were stained strongly by alcian blue, while marked decrease in staining by alcian blue was observed in 12th- and 13th-week human fetuses. The nature of alcian blue positive materials was identified as hyaluronic acid and chondroitin sulfate or dermatan sulfate by enzymatic digestion methods and the Scott-Dorling method. The results suggest that distinction between primary and secondary vitreous is difficult by classical histochemical techniques and electron microscopy, and that the vitreous glycosaminoglycans concentration seems to be high at 7th- and 8th-week embyonic stages and decreases at later fetal stages.     

Randomized phase II study comparing mitomycin, cisplatin plus doxifluridine with cisplatin plus doxifluridine in advanced unresectable gastric cancer

Various chemotherapies have been used to treat inoperable gastric cancer. Most combination therapies include cisplatin (CDDP) and fluoropyrimidine (5-FUs), which are thought of as key drugs. In the present study, we randomly compared mitomycin (MMC) and CDDP plus doxifluridine (5'-DFUR), which is an oral 5-FU and an intermediate metabolite of capecitabine (Xeloda), with CDDP plus 5'-DFUR in advanced unresectable gastric cancer. Regimen A was CDDP (70 mg/m2, by 2-hour intravenous drip infusion on day 1), MMC (7 mg/m2, injected intravenously on day 2), and oral 5'-DFUR (1200 mg/m2, on days 4 to 7, 11 to 14, 18 to 21 and 25 to 28; 3 days rest and 4 days administration). Regimen B was identical to regimen A without MMC. RESULTS: The response rate was 25.0% (8/32 patients) in Regimen A, 17.2% (5/29) in Regimen B (p=0.541). The median survival time was 241 days in Regimen A and 179 days in Regimen B (p=0.498). In Regimen A, although no significant difference was observed, end points such as response rate and suvival improved. Thus, we concluded that a randomized controlled phase III study with more subjects should be conducted.     

Reliability of the mechanomyogram detected with an accelerometer during voluntary contractions

The accelerometer is used for mechanomyogram (MMG) recordings of muscle contractions. Although the mechanical characteristics of other MMG transducers have been determined with reference to the accelerometer, mechanical aspects of the accelerometer itself, including the weight of the transducer, have not been verified. This study was designed to reinvestigate the mechanical variable of the MMG signal detected with an accelerometer, with reference to a laser distance sensor (LDS), and then to clarify the influence of the accelerometer weight on the MMG recording during muscle contractions. The study was performed during mechanical sinusoidal vibrations and during voluntary contractions of the quadriceps muscle. Maximum differences in the amplitude spectral density functions between the LDS signal and the double integral of the accelerometer signal were approximately 4μm. The results verified that the MMG signal from the accelerometer accurately reflected the acceleration of body surface vibration. However, the MMG signal was gradually distorted when weight was added to the accelerometer: the addition of 4.0 g (total 6.0 g, including 2.0 g of accelerometer) substantially attenuated the MMG signal. The results suggest that the appropriate weight for the accelerometer should be less than 5.0 g for measurements of the quadriceps muscle and indicate that the transducer weight must be taken into account for accurate measurement of muscles of different sizes.     

The accuracy of transcutaneous carbon dioxide monitoring during laparoscopic surgery

BACKGROUND: Laparoscopic procedures are considered relatively low-invasive. However, there exists a small but important risk of developing complications related to carbon dioxide (CO2) insufflation. End-tidal CO2 (PetCO2) monitoring may not be a sufficient guide to adjust pulmonary ventilation during laparoscopic surgery, and arterial CO2 (PaCO2) monitoring is not always indicated. We evaluated the accuracy and feasibility of transcutaneous CO2 (PtcCO2) monitoring during laparoscopic surgery. METHODS: Thirty adult patients undergoing abdominal or gynecological laparoscopic surgery were studied. PtcCO2, PaCO2 and PetCO2 were measured before laparoscopy, and 30 and 60 minutes after beginning of CO2 insufflation. PtcCO2 and PaCO2 were also measured in the recovery room under spontaneous respiration. RESULTS: During operation, the PtcCO2 values demonstrated a high degree of correlation with PaCO2 (r = 0.92), and PetCO2 values also demonstrated generally a good correlation with PaCO2 (r = 0.85). The PtcCO2 PaCO2 gradient was -0.6 +/- 2.2 mmHg, while the PetCO2-PaCO2 gradient was -3.9 +/- 2.7 mmHg. In the recovery room, PtcCO2 values still demonstrated a high correlation with PaCO2 (r = 0.91). CONCLUSIONS: The transcutaneous devices provide an effective method for non-invasive monitoring of PCO2 in situations where continuous monitoring of CO2 levels is desired such as peri-operative period of laparoscopic surgery.     

Mechanical behaviour of condenser microphone in mechanomyography

Condenser microphones (MIC) have been widely used in mechanomyography, together with accelerometers and piezoelectric contact sensors. The aim of the present investigation was to clarify the mechanical variable (acceleration, velocity or displacement) indicated by the signal from a MIC transducer using a mechanical sinusoidal vibration system. In addition, the mechanomyogram (MMG) was recorded simultaneously with a MIC transducer and accelerometer (ACC) during voluntary contractions to confirm the mechanical variable reflected by the actual MMG and to examine the influence of motion artifact on the MMG. To measure the displacement-frequency response, mechanical sinusoidal vibrations of 3 to 300 Hz were applied to the MIC transducer with different sizes of air chambers (5, 10, 15 and 20 mm in diameter and 15, 20 or 25 mm long). The MIC transducer showed a linear relationship between the output amplitude and the vibration displacement, however, its frequency response declined with decreasing diameter and decreasing length of the air chamber. In fact, the cut-off frequency (−3 dB) of the MIC transducer with the 5-mm-diameter chamber was 10, 8 and 4 Hz for the length 15, 20 and 25 mm, respectively. The air chamber with at least a diameter of 10 mm and a length of 15 mm is recommended for the MIC transducer. The sensitivity of this MIC transducer arrangement was 92 mVμm⁻¹ when excited at 100 Hz. During voluntary contraction, the amplitude spectral density function of the MMG from the MIC transducer resembled that of the double integral of the ACC transducer signal. The angle of the MIC transducer was delayed by 180° in relation to the ACC transducer signal. The sensitivity of the MIC transducer was reduced to one-third because of the peculiar volume change of air chamber when the MMG was detected on the surface of the skin. In addition, the MIC transducer was contaminated by a smaller motion artifact than that from the ACC transducer. The maximal peak amplitude of the MIC and ACC transducer signal with the motion artifact was 7.7 and 12.3 times as much as the RMS amplitude of each signal without the motion artifact, respectively. These findings suggest that the MIC transducer acts as a displacement meter in the MMG. The MIC transducer seems to be a possible candidate for recording the MMG during dynamic muscle contractions as well as during sustained contractions.