Health effects of acrylonitrile in acrylic fibre factories

The relationship between the degree of exposure and biological effects of acrylonitrile (AN) was studied in 102 workers whose exposure period exceeded five years, and in 62 matched controls, all of whom had been randomly sampled from six acrylic fibre factories in Japan. The six factories were classified into three groups on the basis of AN concentration at workplaces. The most highly exposed group of subjects showed an eight-hour average AN concentration of 4-2 ppm by personal sampling, a mean urinary AN concentration of 360 microgram/1 and a mean urinary thiocyanate concentration of 11-4 mg/1. Medical examination, including the indocyanine green excretion test and multiple clinical chemistry determinations, failed to detect any health effect attributable to AN. Slight liver damage may possibly occur in more highly exposed workers. Urinary AN and thiocyanate determinations may provide more accurate estimates of low-grade exposure (less than 5 ppm).

A double-blind controlled study of clinical efficacy of maprotiline and amitriptyline in depression

A multiclinic double-blind controlled study was performed on the effects of MAP in both inpatients and outpatients with AMT as control drug. 1. Subjects consisted of 41 male and 45 female patients suffering from various types of depression. MAP was assigned to 42 cases and AMT to 44 cases. Of these patients, 14 MAP cases and 10 AMT cases were subsequently dropped for a variety of reasons to obtain 28 MAP cases and 34 AMT cases as evaluable. 2. The global improvement ratings were compared and found not significantly different for any week between the two treatments. 3. The global improvement ratings by the characteristic features of patients did not show any significant difference in any items studied between the two treatments. 4. The symptomatic improvement ratings (on the Hamilton R.S. for assessment by the physician) indicated that AMT was more effective on "anxiety (psychic)." 5. The symptomatic improvement ratings (on the Beck self-assessment scale by the patient) indicated that MAP was more effective on "work" and AMT on "pathos", "feeling of satisfaction", "withdrawal" and "loss of libido." 6. During the treament period, 74.3 percent of the MAP group and 76.9 percent of the AMT group of patients showed some side effects of accompanying symptoms, with no significant difference recognized between the two treatments. Itemwise, however, the incidence of tremor was significantly lower (p-=0.06) in the MAP group. Moreover, the MAP group tended to be less liable to such anticholinergic side effects as dry mouth, constipation, trouble of accomodation, urinary disturbance and palpitation. 7. On the basis of the above findings, it is concluded that MAP is as effective against depression as AMT and less liable to the anticholinergic side effects. It is, therefore, a very useful antidepressant.

[Serological examinations on natural infections with mouse pathogens in inbred mouse strains: difference in antibody detection among the strains (author's transl)]

Serological surveys on several infections were performed on the inbred mouse strains maintained at the Central Institute for Experimental Animals. In the first survey, 11 strains of mouse, which were 8 weeks of age or older and were kept in separate cages in the same animal room, were tested for antibodies to Salmonella enteritidis, Corynebacterium kutscheri, Tyzzer's organisms, Mycoplasma pulmonis, mouse hepatitis virus (MHV), Sendai virus (HVJ), pneumonia virus of mice (PVM) and minute virus of mice (MVM). Positive results were obtained in MHV, HVJ, PVM and MVM. Positive rates for these viruses except for MVM were different among mouse strains. In the second survey, 5 strains of mouse kept together in the same cage for 4 weeks after weaning were examined for MHV and HVJ antibodies. Positive rates to MHV were different among mouse strains as observed in the first survey. For HVJ antibody, no difference was demonstrated in positive rates unlike in the first survey, but the titers varied between the strains. These results suggest the difference in antibody response to natural infections dependent on mouse strains.

Persistence of Sendai virus in a mouse breeder colony and possibility to re-establish the virus free colonies

An epizootic of Sendai virus infection occurred in a mouse breeder colony with respiratory signs, mortality, retarded growth in young and prolonged gestation period in adults. Thereafter, the infection persisted in this colony without any clinical signs and with 90 to 100% antibody positivity in adults. Weanlings had maternal antibodies and no pneumonic lesions. Antibodies were hardly detected in 6-week-old mice with high incidence of red hepatization or congestion in their lungs, but mice over 8 weeks of age had antibody without the lesions. After isolating weanlings and pregnant mice with antibodies from the infected colony, the isolated weanlings and offspring from the isolated dams became negative for Sendai virus antibodies.

[Long term surveys on Tyzzer's disease in three rat breeder colonies (author's transl)]

Retired rats of SD strain from three breeder colonies (A, B and C) were monthly monitored for CF antibody to Tyzzer's organism for 2 to 6 years. In colony A, antibody-positive rats were found at frequencies ranging from 5 tp 100% with a single peak during about one year without any detectable signs of apparent disease. However, in colony B, in spite of the outbreak of the disease, antibody-positive animals were only sporadically detected during about 4 years after the outbreak. Thereafter, in this colony, the antibody was not demonstrated in all animals examined for 2 years, and susceptibility to the disease of 3-week-old rats was the same as that of ones from one-infected colony. Cortisone test did not suggest the infection. In colony C, no antibody-positive rats were detected for 3 years.

Involvement of cyclic GMP in the initial stage of hepatocytes proliferation

A transient rise in cyclic guanosine 3' : 5' monophosphate (c-GMP) in the liver was observed in rats in vivo 10--20 min after partial hepatectomy. A similar increase in c-GMP in the liver was also found in rats in vivo 15 min after infusion of TGH solution (a mixture of triiodothyronine, glucagon, and heparin). In both cases, inductions of ornithine decarboxylase [EC 4.1.1.17] and tyrosine aminotransferase [EC 2.6.1.5] were found 4 hr after the beginning of the experiments. Later, 22 hr after the surgical intervention or hormone infusion, thymidine kinase [EC 2.7.1.21] was activated and liver slices were able to incorporate [3H]thymidine into DNA. These biochemical phenomena were observed commonly in regenerating liver as well as in the liver of rats infused with TGH solution. c-GMP, but not c-AMP, could induce ornithine decarboxylase and tyrosine aminotransferase in isolated, perfused liver.

Cochlear microphonics and SDH activity in the hair cells under anoxia

Cochlear microphonics and succinic dehydrogenase (SDH) activity of the hair cells during anoxia were studied in guinea pigs. After injection of the glucose-glucose oxidase mixture into the cerebellomedullary cistern, the deprivation of the oxygen tension in CSF and perilymph was measured in different time courses. In CSF, oxygen tension was reduced to zero within 60 min while in perilymph the maximal reduction was about a half the original level. The cochlear microphonics responded well to the oxygen tension deprivation in the perilymph. SDH activity, particularly in the outer hair cells was quite parallel to the oxygen tension in perilymph and also to the behavior of the cochlear microphonics. The present results indicate a close relationship between the electrophysiological and histochemical findings and that cochlear microphonics represent the function of the outer hair cells only.

Laryngeal reconstruction by free flap transfer

In the two cases reported herein, a laryngeal cavity was successfully reconstructed with a free flap, using microvascular anastomoses. The revascularized free flap contributed significantly to the maintenance of a patent airway and to the reproduction of an appreciable voice. Our experiences with these laryngeal reconstructions encourage us to try to expand the application of free flaps for reconstructions after head and neck cancer surgery.

Effect of phlorizin on glucose transport in the inner ear

14C-glucose was used as a tracer to study the effect of phlorizin on glucose transport into perilymph and endolymph. The transport was found to be lowered in phlorizin-injected animals compared with that in normal controls. This inhibitory effect corresponding to a phlorizin-sensitive part of glucose transport was greater in the perilymphatic system than in the endolymphatic system. Pathways which are not affected by phlorizin, are considered to exist in both compartments of perilymph and endolymph.

Subtotal pharyngolaryngectomy conservation surgery for carcinoma of sinus pyriformis extending toward the larynx

In newly developed surgery for pyriform sinus tumor extending toward the larynx, the supraglottic portion of the larynx and the vertical half of the larynx on the tumor side are included in the area of resection. The arytenoid and cricoid cartilages on the tumor side and the vertical half of the hypopharyngeal wall are resected. Three out of seven patients remain cured at the end of 5 years and this ratio is the same as that for total pharyngolaryngectomy for pyriform sinus tumor. The resulting voice is somewhat hoarse, however, verbal communication is not remarkably affected. It is concluded that in surgical repair for pyriform sinus tumor extending toward the larynx, subtotal pharyngolaryngectomy is the procedure of choice to preserve the laryngeal function and anticipate reasonable prospects for a cure.

In vitro morphological study of cochlear epithelium

1. The mammalian cochlear epithelium was successfully kept alive in long-term tissue cultures. The Na and K concentration of the culture medium was similar to that of perilymph. 2. The most vulnerable cells in the culture epithelium were the outer and inner hair cells followed by the inner zones cells and the interdental cells of the spiral limbus. The difference in disintegration time between the outer and inner hair cells was about 48 hrs under the same culture conditions. The same phenomenon was noted between the rows of outer hair cells. 3. When the outer hair cells were not supported by Deiters' cells or when the cochlear epithelium was separated between Deiters' cells and Hensens cells, the outer hair cells degenerated quickly. 4. The interdental cells appeared to be relatively highly differentiated and showed much activity. No evidence of secretory function of interdental cells could be obtained. 5. The inner sulcus cells, Hensens cells, Claudius' cells and Reissners membrane cells were flattened and arranged like covering epithelium.

Evaluation of total pharyngolaryngectomy for hypopharyngeal cancer

In 37 patients with hypopharyngeal cancer treated by total pharyngolaryngectomy and radical neck dissection, the 5 year cure rate was 30%. Among these patients, T-1 and T-2 tumors had a 57% and 47% 5 year cure rate respectively. Better results were obtained in those patients with tumor of the posterior pharyngeal wall and tumor of sinus pyriformis extending toward postcricoid region or toward the larynx. In 14 patients treated with various approaches of partial pharyngolaryngectomy, the 5 year cure was 53%. It is concluded that the conservation surgery is the operation of choice for the tumors of T-1 and T-2 in securing the total cure and preserving the laryngeal function.

Centennial conference on laryngeal cancer papers. Primary laryngoplasty

A new procedure is described for the surgical reconstruction of the larynx following total laryngectomy. Postoperatively, the voice was as good as that resulting from Asai's laryngoplasty. Aspiration of fluid into the trachea was minimal. The procedure may be briefly summarized as follows: 1. The lateral portion of both thyroid cartilages are left in situ. 2. The posterior laryngeal wall is formed with the superior horns of the same cartilages. 3. The inner surface of the reconstructed larynx is lined by mucosal flaps from the hypopharynx. 4. The reconstructed larynx is firmly sutured to the base of the tongue. This procedure was employed in 19 cases with an extensive laryngeal carcinoma. In five of them healing was retarded by the formation of postoperative pharyngeal fistulas. All patients regained their voices and their ability to swallow.

Restoration of voice after laryngeal surgeries

Some aspects of speech deficiency in Japanese-speaking patients who had undergone surgeries for laryngeal malignancy were studied. Surgical procedures included reconstructive surgeries after total laryngectomy and conservation surgeries. A series of listener-judgments and some acoustic analyses of speech were made. The recorded voices of the patients were more or less hoarse. The median speaking pitch varied greatly from patient to patient, and often assumed an unusual value. The average articulation score for five Japanese vowels was computed for each subject. The score varied from patient to patient, and was thought to be useful in quantitatively evaluating speech quality. It was shown that certain glottal consonants such as /h/ can be affected by laryngeal surgeries. It was emphasized that the larynx should be regarded not only as a generator or a vibrator, but also as an articulator which produces consonants. The listening tests also revealed that the intonation pattern of Japanese two-syllable nouns can be influenced by laryngeal surgeries, and that distinction among certain words may become impossible as a result. This type of speech problem may require serious consideration in some language environments.

Prereplicative enzymic changes in regenerating rat liver

After partial hepatectomy in rats, the following changes in enzymic activities were observed in the remnant liver during the prereplicative period. In the initial period of the prereplicative process, soon after removal of part of the liver, ornithine decarboxylase [EC 4.1.1.17] and IMP dehydrogenase [EC 1.2.1.14] increase. Subsequently, for entry into the S period, thymidine kinase [EC 2.7.1.75] increases simultaneously with increase in the intracellular cyclic AMP level and decrease in its phosphodiesterase [EC 3.1.4.17].

Effect of the high potassium medium on cultured cochlear epithelial cells

1. A high potassium and low sodium culture medium does not produce morphological change in cochlear epithelial cells such as sulcus cell, Deiters' cell, Hensen's cell, Claudius' cell and Raissner's membrane cell. 2. Interdental cells of spiral limbus are affected by a high potassium medium but the change is to a moderate degree. 3. Outer hair cells degenerate quickly in a high potassium and low sodium medium. The onset and the grade of the degeneration is in a parallel with the potassium concentration, and a concentration of more than 46.4 mEq/l produces an acute and severe degeneration of outer hair cells.