Evaluation of conventional weaning criteria in patients with acute respiratory failure

We evaluated the reliability of conventional weaning criteria from a ventilator during 33 weaning trials on 25 patients with acute respiratory failure (ARF). Of 13 criteria, a ratio of maximal voluntary ventilation to minute ventilation (MV) 2, a vital capacity 12ml·kg^–1, a spontaneous respiratory rate 25 breaths·min^–1, and a MV 10l·min^–1 appeared to be useful for predicting successful weaning outcome. However, even using those criteria, there were many falsely-negative cases. The alveolar-arterial P_{O 2} gradient 350mmHg at an Fi _{O 2} 1.0 was not useful as a predictor of weaning outcome. The present study demonstrates that conventional criteria are frequently inaccurate for predicting weaning outcomes and suggests that the use of some of these criteria may unnecessarily prolong the length of ventilator support. Since ventilation of most patients with poor oxygenation can be successfully discontinued by placing them on a continuous positive airway pressure system, these results suggest that the improvement of oxygenation is not an indispensable prerequisite for weaning from mechanical ventilators.(Okamoto K, Iwamasa H, Dogomori H, et al.: Evaluation of conventional weaning criteria in patients with acute respiratory failure. J Anesth 4: 213–218, 1990)     

Accumulation of L-[2-(F-18)]fluorophenylalanine in peri-infarct area in a patient with acute cerebral infarction

We studied the brain uptake of amino acid in a patient with acute cerebral infarction with L-[2-(F-18)] fluorophenylalanine and positron emission tomography. The increased accumulation of the ligand was specifically found in the peri-infarct area where oxygen metabolism was still maintained but decreased later in the 72-day follow-up period. The kinetic analysis revealed that increased accumulation was not due to increased transport from the blood to the brain but to delayed washout from the brain to the blood. Although the mechanism is still unknown, abnormally high accumulation of L-[F-18]fluorophenylalanine may predict delayed neuronal changes after ischemic insults of the brain.     

Recurrent breast cancer at 21 years after resection detected by serum tumor markers and manifested as dermatomyositis

A 52-year-old Japanese woman developed dermatomyositis. She had undergone a standard radical mastectomy for left breast cancer 21 years earlier. Though no physical sign of recurrent breast cancer appeared clinically, levels of tumor markers were abnormally elevated. Therefore, tamoxifen and CAF therapy were given. Further, the clinical course of dermatomyositis almost paralleled the level of serum tumor markers and the clinical course of her recurrent breast cancer. These markers were useful for detecting the recurrence, following the metastatic disease, and monitoring her response to therapy.     

Ocular findings in Japanese women with nevus of Ota

Background: Nevus of Ota is common in Japanese women, but most patients are not examined ophthalmologically. Methods: We performed ophthalmologic examinations on 16 Japanese women who had had bluish pigmentation in the periorbital region, sclera, and conjunctiva since birth. Results: Fifteen patients had unilateral involvement, and one had bilateral lesions. The visual acuities were good, and the intraocular pressures were within normal range. All patients had a negative family history. Three patients had light pigmentation in the optic disc in the affected eye. Conclusion: We believe that optic disc pigmentation associated with nevus of Ota, as found in these three patients, may be common but have been rarely described.     

Induction of tumor regression by passive transfer of antibody from mice vaccinated with anti-idiotype antibodies resembling a human renal cell carcinoma-associated antigen

We have shown that six different internal image antiidiotype antibodies (Ab2) raised against the combining site of the murine monoclonal antibody G250 (MAbG250; Abl), which specifically reacts with a human renal cell carcinoma (RCC)-associated antigen, induce antigen specific humoral and cellular responses in mice. These six Ab2 can be divided into four mutually exclusive groups: (1) NUH31 and NUH51, (2) NUH44 and NUH82, (3) NUH71, and (4) NUH91. Immunization with NUH82 or NUH91 resulted in Ab3 sera that gave complete protection against tumor challenge. In this study, we tested the antitumor efficacy of NUH82- and NUH91-induced mouse sera (Ab3 sera; Ab3-82 and Ab3-91) in mice with established subcutaneous human RCC xenografts. Mice were treated 3 times per week by intraperitoneal injection of Ab3 sera (0.2 ml) or MAbG250 (250 μg) for 6 weeks. Treatment of NU12 human RCC xenografts of approximately 20 mm(3) expressed as tumor size index (TSI) with NUH-Ab3 sera or MAbG250 resulted in significant tumor growth inhibition compared with tumors treated with Ab3 sera from mice immunized with control immunoglobulin (Ab3-MOPC). In all Ab3-NUH treated mice, tumors stabilized or disappeared completely. In contrast, Ab3-MOPC treatment did not result in any antitumor effects. Tumor remnants in Ab3-NUH treated animals contained viable tumor cells surrounded by infiltrating mouse cells, whereas no infiltration was observed in control tumors. These findings demonstrate that Ab3 sera obtained from NUH82- or NUH91-immunized mice are very effective in eradicating established RCC [i.e., Ab2 vaccination may be able to eradicate (minimal) residual disease in RCC patients].     

Pupillary responses in normal subjects following auditory stimulation

To clarify pupillary responses of humans following auditory stimuli, we studied both eyes of 61 normal subjects using a computed pupillograph. Unilateral auditory stimulation elicited pupillary dilatation in all cases. Pupillary responses were classified according to duration as being either “long” or “short”. The duration of dilatation was 1530±320 ms (mean±SD) in the longlasting group (n=45) and 850±250 ms in the short-lasting group (n=16). The latency time for dilatation was 460±80 ms. Both eyes of each subject showed the same response. Two drops of 10% guanethidine, a sympathetic blocking agent, were applied to one eye of 3 subjects. Although the early phase of dilatation was barely affected, the late phase was inhibited, as seen in long-lasting dilatation. The short-lasting response was unaffected. We conclude that the long-lasting response consists of an early pupillary dilatation due to inhibition of parasympathetic nervous activity and a late dilatation due to excitation of sympathetic activity. The short-lasting response is produced only by inhibition of the parasympathetic component.     

Total Esophagectomy versus Proximal Esophagectomy for Esophageal Cancer at the Cervicothoracic Junction

To investigate the adequate extent of esophagectomy and lymphadenectomy for an esophageal cancer localized at the cervicothoracic junction, the mortality and morbidity rates, survival rates, and patterns of recurrence were retrospectively analyzed in two groups—14 patients who underwent total esophagectomy with or without laryngectomy and 15 patients who underwent proximal esophagectomy with or without laryngectomy—at Kurume University Hospital from 1981 to 1996. Proximal esophagectomy with or without laryngectomy resulted in a lower hospital mortality rate and better overall survival for patients who underwent curative esophagectomy compared with total esophagectomy with or without laryngectomy. Multivariate analysis indicated that the extent of esophagectomy (total esophagectomy versus proximal esophagectomy) was not a prognostic factor. The incidence of recurrence was not different between the two groups. Lymph node metastasis or recurrence from such esophageal cancers was localized to the neck and upper mediastinum. For an esophageal cancer localized at the cervicothoracic junction, therefore, proximal esophagectomy with or without laryngectomy and with cervical and upper mediastinal lymphadenectomy could be better indicated for preselected patients.     

Post-traumatic pituitary apoplexy--two case reports

A 60-year-old female and a 66-year-old male presented with post-traumatic pituitary apoplexy associated with clinically asymptomatic pituitary macroadenoma manifesting as severe visual disturbance that had not developed immediately after the head injury. Skull radiography showed a unilateral linear occipital fracture. Magnetic resonance imaging revealed pituitary tumor with dumbbell-shaped suprasellar extension and fresh intratumoral hemorrhage. Transsphenoidal surgery was performed in the first patient, and the visual disturbance subsided. Decompressive craniectomy was performed in the second patient to treat brain contusion and part of the tumor was removed to decompress the optic nerves. The mechanism of post-traumatic pituitary apoplexy may occur as follows. The intrasellar part of the tumor is fixed by the bony structure forming the sella, and the suprasellar part is free to move, so a rotational force acting on the occipital region on one side will create a shearing strain between the intra- and suprasellar part of the tumor, resulting in pituitary apoplexy. Recovery of visual function, no matter how severely impaired, can be expected if an emergency operation is performed to decompress the optic nerves. Transsphenoidal surgery is the most advantageous procedure, as even partial removal of the tumor may be adequate to decompress the optic nerves in the acute stage. Staged transsphenoidal surgery is indicated to achieve total removal later.