A simple, highly reproducible method of synchronizing cultured Plasmodium (P) falciparum was studied. When culture of P. falciparum was kept at 0°C for 48 hours, the parasites showed a stepwise multiplication curve in 37°C incubation, while nontreated parasites manifested a linear continuous propagation pattern. Morphological observation revealed that parasites grew synchronously after cold treatment. Only parasites at the stage of the young ring form survived after 0°C exposure, and this caused homogeneity of the developmental stage of treated parasites. Syn-chronicity of the treated parasites was also confirmed by boosted DNA and protein syntheses when parasites reached the late trophozoite stage. Several advantages over other synchronization methods are discussed.

View full abstract

Extensive studies on malaria vaccine have been made to provide new technology for the control of the disease, which is still prevalent in the tropics. Genetic engineering to produce antigen epitope on malaria parasites raised new possibilities in this field, however, a vaccination model of long lasting effect still remains to be investigated. The present study was undertaken to propose a new malaria vaccine model using a rodent malaria system. An established strain, Plasmodium (P) berghei NK65XAT (XAT), is a permanent attenuated derivative of P. berghei NK65 (NK65). Only one parasite of the original NK65 inevitably kills one mouse, while, 10⁷ XAT strain parasites caused a self-resolving type of low parasitemia in mice, and the mice remained apparently healthy. The mice inoculated with 10⁶ XAT parasites showed a potent long-lasting resistance against challenge inoculation with 10⁵ NK65 parasites of high virulence. Complete protection was shown by day 120 after immunization inoculation with XAT. Survival rates of 20-40% were recorded from day 180 to day 360 following the vaccination. The immunized mice were also completely resistant to challenge by a different strains of P. berghei ANKA. Immunity was also effective against challenge by different species of rodent Plasmodia, although 100% protection was not attained. Radical chemotherapy on mice inoculated with XAT did not reduce the immune effect. Hence, the resistance conferred on the immune mice was a different type of immunity from the classic premunition. It has been widely known that malaria causes some type of immune suppression in the host. However, so far as responsiveness of spleen cells to Con A, PHA, LPS and the parasite antigen concerned, suppression was not observed in mice immunized by XAT inoculation. These findings support the view that attenuated live type malaria vaccine could provide potent, long-lasting immunity without endangering the host.

View full abstract

For residual biliary stones, washing of the biliary tract with saline, heparinized saline or solvent agents has been used, but it has not been very effective.
We obtained good results in extraction of residual biliary stones by using a cholangioscope postoperatively.
Thirty-one patients with residual biliary stones (11 with choledocholithiasis, and 20 with hepaticolithiasis) have been treated by cholangioscopic extraction.
We succeeded in the extraction in 90.9% of the patients with common bile duct stones, and 90.0 % of the patients with intrahepatic bile duct stones.
In the treatment for hepaticolithiasis, we usually cannot remove all of the stones at the time of the operation, so that we have to perform a convenient operation in order to remove the stones postoperatively.
Our operation, transjejunal intubation to the intrahepatic bile duct with a Silicon tube (over 7mm) through the choledochojejunostomy, is one of the most effective and safest procedures for the postoperative cholangioscopic extraction of residual biliary stones.

View full abstract

Diseases in the oral cavity of infants are very different from those of adults because the oral tissues of infants are growing, and the oral conditions such as food and drink or dental treatment materials are different. There are many indistinct points in the case of cysts or tumors of infants as there are few case reports on them. The authors have experienced the following interesting cases :
Case 1 An 11-month-old male with a mucous cyst located in the left palate glossal arch.
Case 2 A 1-year-old female with a fibroma located in the median palate.
Case 3 A 1-year 8-month-old male with an embryonal rhabdomyosarcoma located in the left margin of the posterior tongue.
Each patient was treated by resection under general anesthesia and the postoperative course was uneventful. Cases like the above are relatively infrequenct among infants. It is ordinarily thought that both mucous cysts and fibroma are caused by local factors and inflammation. Refering to our cases, we suggest that such diseases as mucous cysts and fibroma are related to antecedent embryological causes.

View full abstract

Secondary carcinoma of the testis is rare. Two cases are presented ; one is that of 61-year-old man who had a secondary involvement of the testicular parenchyma by a mucinous carcinoma of the ascending colon, and the other is that of a 52-year-old man whose tunica vaginalis testis was involved by a poorly differentiated adenocarcinoma of the stomach. The literature concerning secondary carcinoma of the testis is reviewed.

View full abstract

A 27-year-old female was admitted to the Gunma University Hospital. She had a 6-year history of anemia, edema and abdominal pain. Laboratory studies revealed iron-deficiency anemia, hypoproteinemia and protein-losing enteropathy without inflammatory signs. Radiography of the small intestine showed multiple ulcers of the ileum. After segmental resection of the small intestine, anemia and hypoproteinemia improved gradually, and the abdominal pain disappeared. The microscopic findings of the resected small intestine were consistent with nonspecific multiple ulcers of the small intestine. The patient had splenomegaly which has not been described in the previous literature.

View full abstract