Tonotopic organization of auditory cortical fields delineated by parvalbumin immunoreactivity in macaque monkeys.

Tonotopic maps, obtained from single and multi-unit recordings in the primary and surrounding areas of the auditory cortex, were related to chemoarchitecture of the supratemporal plane, as delineated by immunoreactivity for parvalbumin. Neurons in the central core were sharply tuned and formed two complete tonotopic representations corresponding to the primary auditory area (AI) and the rostral (R) area. High frequencies were represented posteriorly in AI and anteriorly in R, the representation reversing in the anterior part of the core. Neurons in regions of less dense immunostaining previously described as lateral (L) and posteromedial (P-m) fields, showed broader frequency tuning. Two tonotopic representations were found in L: in an anterolateral (AL) field, corresponding to a field previously reported by others, high frequencies were represented anteriorly and low frequencies posteriorly; in a posterolateral field (PL) the trend reversed. There was a further reversal on entering P-m from the high frequency representation in PL and progressively lower frequencies tended to be represented more medially in P-m, but P-m may contain two representations reported by others. Neurons in the previously described anteromedial (A-m) and medial (M) fields of weaker immunostaining, were even more broadly tuned. A tonotopic progression from low frequency representation posteriorly to high frequency representation anteriorly was observed in the medial field. Frequency representation in A-m remains uncertain. No tonotopic representation could be demonstrated with the stimuli used in the zones of very weak parvalbumin immunostaining outside AL, PL, P-m, A-m, and M. The properties of neurons in the core and surrounding zones are likely to reflect inputs from the ventral and dorsal medial geniculate nuclei, respectively. The fields outside the core seem to be the starting points for separate streams of auditory corticocortical connections passing into association cortex.

Histologic study of the recurrent laryngeal nerve in spasmodic dysphonia.

It has been reported that there were no significant changes in the recurrent laryngeal nerves of patients with adductor spasmodic dysphonia, which could explain the cause of this disease. However, the researchers who made these reports appeared to have investigated only the extralaryngeal part of the nerve involved in the neck. Because the recurrent laryngeal nerve contains many components that distribute to various organs, we must study in greater detail a more peripheral part of the motor nerve, which has a much closer relationship to vocal cord movements. At the time of surgery we obtained specimens of the thyroarytenoid branches of the recurrent laryngeal nerves in two female patients with adductor spasmodic dysphonia. Although histologic analysis revealed no apparent signs of either destruction or degeneration, the percentage of thin nerve fibers, the diameter of which may range from 5 to 10 microm, was higher than in normal controls. This suggests the possibility of a neurologic abnormality in the larynges of ASD patients.

Epidemiology of glaucoma in Japan--a nationwide glaucoma survey.

A population-based, collaborative glaucoma survey was conducted in seven regions throughout Japan, during the years of 1988 and 1989. The total number of subjects examined was 8,126 out of 16,078 residents aged 40 years or older, representing a participation rate of 50.54%. There were no significant differences in background factors between participants and randomly sampled nonparticipants. A mainstay of the screening consisted of tonometry and fundus photography with nonmydriatic camera, followed by automatic perimetry as a recall examination. Overall prevalences obtained were primary open-angle glaucoma (POAG) 0.58%, low-tension glaucoma (LTG) 2.04%, primary angle closure glaucoma (PACG) 0.34%, other types of glaucomas 0.60%, and ocular hypertension (OH) 1.37% at the time of screening. The very high prevalence of LTG and extremely low prevalence of OH in the Japanese might reflect a racial peculiarity in the age-specific trend of the intraocular pressure. The prevalence of PACG was found much higher in Japanese than in Caucasians, with a predilection for women. Racial peculiarities as revealed in this study were discussed, with particular reference to the refractive status in the Japanese that showed progressive decrease in myopia with age.

Penetrating injuries to the oropharynx.

A review was made of 12 cases of penetrating injuries to the oropharynx seen at Musashino Red Cross Hospital during the period from 1984 to 1988, and their records were compared with those of past cases with similar injuries reported in a survey for the period between 1949 and 1959. Most of the patients were children under the age of four and were injured when they fell with a sharp-edged object in the mouth. Penetrating injuries to the oropharynx occasionally cause severe complications, including retropharyngeal abscess and mediastinitis. This type of injury should be called a 'pencil injury'.

Regional specular microscopy of endothelial cell loss after intracapsular cataract extraction: a preliminary report.

In a group of 10 patients (12 eyes) undergoing intracapsular cataract extraction, corneal endothelial cell loss was serially investigated by means of regional specular microscopy. Prevoperatively there were no significant regional differences in the endothelial cell density. Two weeks after surgery, the superior endothelium alone showed a significant cell loss (15.6%). Whereas, a definite endothelial cell loss occurred in each region of the cornea one month after surgery. The cell loss was greater in the superior (22.8%) and lower in the inferior (4.7%), respectively, when compared to that seen in the central cornea (9.6%). In each region, cell loss continued 3 months postsoperatively, but no significant cell loss occurred thereafter. These results suggest that the entire endothelial cell population may participate in the healing of the damage associated with intracapsular cataract extraction and that regional specular microscopy can be of help for detailed evaluation of such a damage.

Botulinum toxin treatment for spasmodic dysphonia.

Effective treatment of adductor type spasmodic dysphonia with botulinum toxin injection is presented. Patients showed objective and/or subjective improvement in phonation. The beneficial effect lasted for approximately 3 months. An immediate complication is temporary hoarseness or aphonia, mainly due to diffusion of BT into the adjacent muscles. This is avoided by limiting the injection to one vocal fold only and by keeping the dose at less than 5 units. Insertion technique of the needles, such as percutaneous and laryngoscopically controlled techniques, are discussed.

[The amnioinfusion therapy of saline solution for premature rupture of the membranes before 27 weeks' gestational age].

Saline solution amnioinfusion was performed for 12 cases of preterm PROM before 27 weeks gestational age complicated by oligohydramnios in order to suppress chorioamnionitis, prevent fetal pulmonary hypoplasia and delay delivery. The results were as follows. 1. The mean gestational ages at diagnosis of premature rupture of membranes and initiating saline solution amnioinfusion were 23.6 +/- 2.9 weeks and 24.9 +/- 1.5 weeks, respectively. The mean duration of saline solution amnioinfusion was 14.7 +/- 11.9 days. The mean gestational age at delivery was 27.2 +/- 1.7 weeks. The mean birth weight was 1,056 +/- 220g. 2. Saline solution amnioinfusion was effective in relieving oligohydramnios in all cases. No pulmonary hypoplasia was observed in the infants. 3. Clinically saline solution amnioinfusion was effective in suppressing chorioamnionitis in 9 cases out of 12. Histologically the picture of chorioamnionitis was revealed in 10 cases out of 12. no serious infection was observed in the infants. 4. Nine infants out of 12 survived. There were 2 IUFD and one neonatal death. The perinatal survival rate was 75%. 5. It is concluded from the above results that saline solution amnioinfusion is an effective treatment for preterm PROM before 27 weeks' gestational age.