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Biomedical subjects

P C Fan

Publications and source records attributed to P C Fan.

At least 55 records · Page 3Linked to original sources
PubMed1994

Determination of the earliest appearance and peak count of microfilariae of Wuchereria bancrofti and Brugia malayi after taking a single dose of diethylcarbamazine at noon.

Six nocturnal microfilarial carriers (three with Wuchereria bancrofti and three with Brugia malayi) from mainland China were selected to determine the earliest appearance and peak count of microfilariae (mf) administration of DEC at noon. Before diethylcarbamazine (DEC) administration, blood samples of 60 microliters were obtained by finger-prick at 2 h intervals for 24 h. A blood sample was then taken just before each carrier intaking 100 mg, 150 mg or 200 mg of DEC orally at noon. After drug administration, blood samples were obtained at 45 and 60 sec and at 2, 3, 4, 5, 10, 15, 20, 25, 30, 40, 50, 60, 90 and 120 min. Samples were then taken at 2 h intervals for the next 2 h and at 6 h intervals for the next 7 days. Both W. bancrofti and B. malayi showed typical nocturnal periodicity. One mf was first detected in the peripheral blood 45 sec in a mf. carrier. The mf peak counts were found 1-40 min after DEC administration at noon. The nocturnal cycle was distributed during the first two days after DEC administration. It became regular with a much lower peak count by the third day after administration. The results of the present study indicate that the provocative effect of DEC on the mf is very fast; the first appearance in the peripheral blood vessels could be under 45 sec.

Animals↗
PubMed1994

Experimental transfer of Paragonimus westermani from rodents to rodents following subcutaneous and intraperitoneal routes.

In order to investigate the experimental transfer of Paragonimus westermani from rodents to rodents following subcutaneous and intraperitoneal routes, 13 rats and 23 mice were inoculated with a total of 115 (1 mature and 114 immature) worms of P. westermani subcutaneously and intraperitoneally. The age of worms before transfer was 25-193 days. The transfer was performed immediately after worm collection from rodents which were killed at various intervals from 4 to 144 days after infection. The location, development and size of worms were recorded. An infection rate of 58% (or 21/36) was demonstrated in rodents after experimental transfer of P. westermani by intraperitoneal and subcutaneous routes. Twenty-seven worms were recovered, giving a worm recovery rate of 23.5%. The rate was significantly higher by the subcutaneous route (34.8%) than by the intraperitoneal route (20.7%) but no difference was found between mice (23.9%) and rats (23.0%). The sizes of worms in the abdominal cavity, pleural cavity and thoracic muscles of mice, and in the leg muscles of rats were much less than in the pleural cavity and lung cysts of rats. A mature worm (7 x 5 mm) and numerous eggs were found in the uterus and pleural cavity of one rat. It is evidence that these rodents are unfavourable definitive hosts of P. westermani, because the worm size, infectivity, maturation and egg production are usually very low. However, the worms are usually widely distributed in their rodent hosts and remain small in size for a long period. Therefore, these rodents are good paratenic hosts for P. westermani and can play an important role in infecting cats and dogs with P. westermani in the laboratory.

Animals↗
PubMed1994

Cross protection against Taenia taeniaeformis in rats vaccinated with non-viable oncospheres of Asian Taenia or T. saginata.

It was determined to examine whether rats injected with non-viable oncospheres of Asian Taenia or Taenia saginata became resistant to challenge infection with eggs of Taenia taeniaeformis, since (a) metacestodes of Asian Taenia and T. taeniaeformis develop in the liver of pigs and rats, respectively, and (b) Asian Taenia and T. saginata have human origins. Rats injected intravenously or subcutaneously with complete Freund's adjuvant with non-viable oncospheres of Asian Taenia showed statistically significant resistance to challenge infection with eggs of T. taeniaeformis, whereas those injected with non-viable oncospheres of T. saginata did not show any resistance.

Animals↗
PubMed1994

Encapsulated egg deposition pattern of Schistosoma japonicum in the peritoneal cavity of mice.

Thirty-four albino mice were each exposed to 20 cercariae of Schistosoma japonicum by the intraperitoneal or percutaneous route and killed after 60-127 days. The peritoneal cavity of each mouse was flushed and worms in the portal vein system were perfused with citrated saline. After sedimentation, washings were examined microscopically. Mature worms were only found in the portal vein system. The worm recovery rate was much higher by percutaneous infection (61.2%) than by intraperitoneal (37.1%). The encapsulated egg granulomas were observed either in the peritoneal cavity or on the intestinal wall; the mean number of encapsulated egg granulomas was also higher in the former (1.6) than in the latter (0.6). The average number of eggs per granuloma was very similar by both routes (10.7 and 11.4). The mean size of encapsulated egg granulomas (529 microns) was increased correspondingly with the number of eggs (range 181-985 microns). The percentage of viable eggs within the granulomas in the peritoneal cavity (77%) was much higher than those on the intestinal wall (18%). Encapsulated egg granulomas were usually ovoid although some had an irregular shape.

Animals↗
PubMed1994

Experimental infection of an isolate of Taenia solium from Hainan in domestic animals.

The present study was designed to determine the susceptibility of domestic animals to an isolate of Taenia solium from Hainan Province, People's Republic of China. A total of 162 cysticerci were recovered from two pigs and 21 from two dogs after experimental inoculation. Cats, goats and a calf were not susceptible to T. solium. Cysticerci were recovered mainly from muscles of the pigs and all were alive. The remainder were in the liver and only one was alive. In the dog, all cysticerci were recovered from the muscles and all were alive.

Animals↗
PubMed1994

Hypomelanosis of Ito associated with West syndrome: report of a case.

Hypomelanosis of Ito (HI) is a rare neurocutaneous disorder characterized by hypopigmented macules along the Blaschko line and multiple abnormalities, including seizures, developmental retardation, ophthalmologic defects, and chromosome mosaicism. We report a four-month-old female baby with typical skin lesions on the right upper limb, chest, and scalp, noted at the age of one week. She also had a seizure disorder which manifested as neck flexion and hand gripping with series formation from the age of three months. Electroencephalogram (EEG) demonstrated modified hypsarrhythmia. The characteristic clinical and electroencephalographic features favored the diagnosis of West syndrome. Magnetic resonance imaging revealed an absence of abnormal neuronal migration. The auditory brainstem evoked response, nerve conduction velocity, and ophthalmologic examinations were all within normal limits. The seizure responded to adrenocorticotropic hormone therapy on the 12th day of initial therapy, and the EEG became normal. However, another different pattern of seizures characterized by staring and lateral gaze in a right upward direction occurred two weeks later. Carbamazepine and phenobarbital were added to the therapeutic regimen. She was regularly followed up at the outpatient department every two weeks after one-and-a-half months of hospitalization. Infantile spasms with evidence of hypsarrhythmias in the EEG recurred at seven months of age. Oral steroid therapy reduced seizure frequency by 80%. As far as we know, this is the first case report of HI combined with infantile spasms in Taiwan.

Female↗
PubMed1993

Imported Opisthorchis viverrini and parasite infections from Thai labourers in Taiwan.

In order to determine the prevalence of intestinal parasites among labourers from Thailand in Taiwan, the stool samples from 1364 Thai labourers were examined by the formalin-ether concentration method and 18.0% were found to be infected with one or more parasites. The infection rates of hookworm, Opisthorchis viverrini, Strongyloides stercoralis, Enterobius vermicularis, Ascaris lumbricoides, Hymenolepis nana, Capillaria philippinensis, Schistosoma japonicum, Echinostoma sp., Entamoeba coli, Giardia lamblia, and Entamoeba histolytica, were 7.6%, 7.0%, 3.2%, 0.5%, 0.3%, 0.1%, 0.1%, 0.1%, 0.1%, 0.4%, 0.2%, and 0.1% respectively. The prevalence was highest among the 21-25 age group (24.8%). Among the 245 infected persons, 91% were infected with one parasite, 8% with two parasites and 1% with three parasites. The finding that parasitic infections are prevalent among Thai labourers demonstrates the need for control measures in foreign labourers in Taiwan and further studies to determine the susceptibility of O. viverrini to the snail hosts of Clonorchis sinensis.

Adult↗
PubMed1993

Experimental infection of Paragonimus westermani in mice and rats.

To determine the infectivity and maturity of metacercariae of Paragonimus westermani after keeping at low temperature for a long period, 45 mice and 45 rats were each infected with 20 metacercariae which were kept at 4 degrees C for 8 to 234 days. The worm recovery in mice increased with age of worm and reached a peak of 32% at 41-50 days and then decreased with age. The rate in rats first decreased to a lowest point of 6% at 71-100 days and then increased with age. In 42 infected mice and 41 infected rats, 187 immature worms (183 tiny and 4 juvenile ones) and 190 worms (164 tiny, 19 juvenile and 7 mature ones) were recovered respectively. Two worm cysts with eggs only and 8 empty worm cysts were also found in the rats. In addition, the frozen metacercariae can still develop to mature worms in SD rats.

Animals↗
PubMed1992

Eating habits of east Asian people and transmission of taeniasis.

In order to understand the role of raw meat and viscera eating habits in the transmission of taeniasis in Asian countries, 1502 infected aborigines in ten mountainous districts/towns of six counties in Taiwan, 58 infected persons in two villages on Cheju Island, Korea, and 97 cases in Ambarita District on Samosir Island, North Sumatra, Indonesia were studied during the field surveys. All infected Taiwan aborigines had the habit of eating raw meat and viscera of wild and/or domestic animals. Among these aborigines, 73% ate wild boar, 66% flying squirrel, 65% wild goat, 56% muntjac, 49% wild rats, 46% monkey, 38% hare, 20% civet-cats, 18% weasel, 17% pheasant, 14% squirrel, 4% grouse, 1% deer, 1% snake, less than 1% bamboo partridge, less than 1% frog, less than 1% bear, less than 1% dog, and less than 1% fox. Of the 58 infected persons with Taenia on Cheju Island, Korea, 72% ate raw meat and/or viscera of pig and cattle, 19% raw pork only, and 9% raw beef only. Among 12 infected persons infected with T. saginata-like tapeworms, 7 had eaten raw pork, 2 raw beef and pork and 3 raw pork. Almost all of the 97 cases of taeniasis on Samosir Island of North Sumatra, Indonesia, had eaten only undercooked pork. Eleven of 15 cases were found to be infected with T. saginata-like tapeworms. Eating habits observed suggest an unusual way of transmission of Taenia in East Asia.

Adolescent↗
PubMed1992

Experimental infection of Philippine Taenia in domestic animals.

In the present study, six 34-44-day-old Small-Ear-Miniature pigs and one 14-day-old Holstein calf were each fed 10,000 Philippine Taenia eggs and sacrificed 27-43 days after inoculation. The infection rate was 100% for both pigs and calf with cysticerci recovery rates of 11 and 6%, respectively. A total of 6431 cysticerci were recovered only from the livers of the six pigs and 597 only from the liver of the calf; more occurred in the parenchyma (pigs 75%, calf 83%) than on the surface (pigs 25%, calf 17%). Mature cysticerci were found in four of the six pigs. A total of 317 cysticerci recovered from the pig livers were mature and the rest were either immature (926), degenerate or calcified (5188). All 597 cysticerci recovered from the liver of the calf were degenerate or calcified. Measurements of length, width, diameter of protoscolex, rostellum, and sucker and hooklet pattern indicated that Philippine Taenia is very similar to Taenia from Taiwan, Korea, Indonesia and Thailand and very different from classical T. saginata and T. solium.

Animals↗
PubMed1992

Clinical manifestations of taeniasis in Taiwan aborigines.

From 1974 to 1989, a total of 24,500 aborigines at 67 villages in ten mountainous districts/towns in Taiwan were examined for the Taiwan Taenia infection and 12% were found to be infected. In order to define the clinical manifestations of taeniasis caused by the Taiwan Taenia, 1661 aborigines in ten mountainous districts were surveyed. The overall clinical rate was 76%. The clinical rate was highest among Atayal aborigines (81%), followed by Bunun (66%) and Yami (61%) aborgines and lowest among Ami aborigines (40%). Among 1153 infected people, 10% had passed gravid segments in the faeces for less than 1 year, 24% for 1-3 years, 17% for 4-5 years, 23% for 6-10 years, 16% for 11-20 years, 7% for 21-30 years, and 3% over 30 years. Twenty-six occurrences of gastrointestinal and neurological symptoms were reported by 1258 infected persons. Passing proglottides in the faeces (95%) was the most frequent sign, followed by pruritus ani (77%), nausea (46%), abdominal pain (45%), dizziness (42%), increased appetite (30%), headache (26%), etc.

Animals↗
PubMed1992

Experimental infection with Taenia saginata (Poland strain) in Taiwanese pigs.

Two 22-day-old Landrace-Small Ear Miniature (L-SEM) pigs, five 45 to 66-day-old Small Ear Miniature (SEM) pigs, and one 16-day-old Holstein calf were each fed 1000, 3000 or 10,000 Taenia saginata (Poland strain) eggs respectively and killed 34-77 days after inoculation. Four of the five SEM pigs and the Holstein calf were susceptible to this parasite. However, two L-SEM pigs and one SEM pig remained negative. The cysticerci recovery rates for the SEM pig and Holstein calf were 36% and 3%, respectively. All cysticerci from the SEM pigs were found in the livers, more in the parenchyma (89%) than on the surface (11%). Only eleven cysticerci in two SEM pigs were mature and the remainder were either immature, degenerated or calcified. The cysticerci in the calf were distributed throughout the body: leg muscles (248), heart (27), tongue (17), intercostal muscles (14), diaphragm (5), kidney (1) and liver (1). Most (299) of the cysticerci were mature, one was immature and 13 were degenerated or calcified. The length, width, diameter of the protoscolex and sucker of the cysticerci from the calf were larger than those from the SEM pigs. However, the diameter of the rostellum of the latter was slightly larger than the former. Hooklets were not found on any mature cysticercus recovered. The results of the present study provide evidence that the SEM pig can be used as an experimental intermediate host for T. saginata.

Animals↗
PubMed1992

Diethylcarbamazine treatment of bancroftian and malayan filariasis with emphasis on side effects.

A total of 1015 filarial carriers were hospitalized and treated with DEC either in a long course with light doses (6, 7, 8, 9 or 10 mg kg-1 b.w. divided into three doses daily for seven days) or in a short course with heavy doses (15 mg kg-1 b.w. once daily for one, two or three days). The efficacy of the long course (85%) was much higher than that of the short course (59%); but the reaction rate following the heavy dose (87%) was higher than that following the light dose (72%). For Brugia malayi infections the overall efficacy was 92% and the reaction rate 82%, for mixed infections the respective rates were 85% and 77%, and for Wuchereria bancrofti infections 82% and 69%. The cure rates decreased from 93% in carriers with one to 10 microfilariae in 60 microns blood to 63% in those with over 100 Mff in 60 microns blood. Febrile reactions developed in 92% of carriers with mixed infections, in 91% of those with B. malayi, and in 84% of those with W. bancrofti. Overall, 63% of those treated were free of microfilariae on the last day of treatment, and 92% were free 48 months after treatment.

Animals↗
PubMed1992

Imported kala-azar: a case report.

A 77-year-old man returned from Honan Province, mainland China, and developed intermittent fever and loss of body weight. On physical examination there was evidence of chest infection but no lymphadenopathy or hepatosplenomegaly. Laboratory data suggested anemia, thrombocytopenia and polyclonal gammopathy. The diagnosis of Leishmaniasis was finally established by bone marrow aspiration which disclosed Leishman-Donovan bodies. Unfortunately, the patient expired soon after the diagnosis was made and a partial autopsy was performed. Kala-azar is a rare disease in Taiwan. However, it should be suspected in those patients who have visited the endemic areas, even though the clinical manifestations are atypical.

Aged↗
PubMed1992

Evaluation of efficacy of four pediculicides against head louse (Pediculus capitis) infestation.

To evaluate the efficacy and to determine the minimum effective dosage of four pediculicides against head louse infestation, as well as to select a safe, effective, practical, and cheap agent, 1,657 infested school children in 25 primary schools in Szu-Hu, Kou-Hu, and Ku-Keng Districts of Yunlin County were treated and 1,611 of them were examined. The overall cure rate was 73% and the rate for boys (84%) was higher than that for girls (71%). The cure rate of Nix (permethrin 1%) cream rinse was 81%. The cure rate for single dosages of 1, 2, 3 and 4 cases/tube (56 gm/tube) was 87%, 83%, 81% and 71%, respectively. The cure rate of Para aerosol (bioallethrine 0.66%) was 78%. The cure rate for single dosages of 30 and 40 cases/tube (90 gm/tube) was 87% and 70%, respectively. The cure rate of Prioderm (malathion 1%) cream shampoo was 64%. The cure rate for single dosages of 10, 15 and 20 cases/tube (40 gm/tube) was 74%, 71% and 52%, respectively. The cure rate of Delice (1% gamma benzene hexachloride) was 71%. The cure rate for single dosages of 5 and 10 ml/case was 64% and 76%, respectively. Of the 226 infested girls, 181 (80%) were found to be infested with 1-10 head lice, 33 (15%) with 11-50 lice, 7(3%) with 51-100 lice and 5 (2%) with over 100 lice. Of the 2,160 head lice collected, 1,788 (83%) were nymphs, 284 (13%) females, and 88 (4%) males. The mean number of head lice in each infested girl was 10 (range 1-137). The low cure rates obtained in the present study may be due to the fact that many school girl & have long hair. In comparison, Nix had the highest cure rate (81%) but the highest price (NT$ 120/case). The cure rate and price of Para aerosol (78%, NT$ 7.2/case) and Delice (71%, NT$ 16.7/case) came next. Prioderm (64%, NT$ 10.0/case) had the lowest rate and a slight offensive smell. Preliminary trials show that based on the cost-effectiveness, Para aerosol is best in head louse infestation control.

Allethrins↗
PubMed1992

Studies of taeniasis in Taiwan. XIV. Current status of taeniasis among Yami aborigines on Lanyu Island, Taitung County, southeast Taiwan.

In December 1989, 1,457 Yami aborigines in six villages on Lanyu District (Lanyu Island), Taitung County, Southeast Taiwan, were examined by questionnaire and demonstration of the proglottides or by scotch tape perianal swab technique for taeniasis. The overall infection rate was 5%. The highest rate was found at Yehyin (8%) and the lowest at Yujen (2%). However, the rate did not significantly differ among the villages. The infection rate peaked in the 51-60 yr age group (15%) and the lowest rate was observed in the 11-20 yr age group (less than 1%). No infection was found in the 21-30 yr age group. The infection rates of men and women were similar (5%). Twenty-one per cent of 304 families was found to include one or more infected members and a family with five infected person was observed at Yehyin. The infection rate of taeniasis on Lanyu Island decreased from 16% in 1984 to 5% in 1989. However, 51 persons who were negative in 1984 were positive at present, 26 were found to be positive in both studies, and 216 (12 died) who were positive in 1984 were now negative. These results indicate that the Yami people still eat raw meat and viscera of animals.

Adolescent↗
PubMed1991

Characterization and detection of a newly described Asian taeniid using cloned ribosomal DNA fragments and sequence amplification by the polymerase chain reaction.

DNA isolated from a newly described taeniid from Taiwan which shows adult characters indistinguishable from those of Taenia saginata was compared to DNA from T. saginata and nine other cestodes by restriction endonuclease digestion of genomic DNA and Southern blot analysis using 32P-labeled total cestode RNA and cloned ribosomal RNA gene fragments as probes. Hybridization patterns of Taiwan Taenia DNA revealed distinct variations from that of T. saginata and Taenia solium as well as all other cestode DNAs examined; however, similarities in restriction maps and sequence data between cloned ribosomal gene fragments from Taiwan Taenia (pTTr 3.1) and T. saginata (pTSgr 3.1 and PTSgr 2.4, respectively) suggest close evolutionary relatedness between these two taeniids. DNA sequence amplification from genomic DNA using oligonucleotide primers homologous to regions on both the 2.4- and 3.1-kb fragments was able to delineate between Taiwan Taenia and T. saginata by generating 1.0- and 0.29-kb fragments, respectively. Results demonstrated that Taiwan Taenia is not exclusive to Taiwan but exists in other parts of Eastern Asia and that adult morphology is insufficient for its detection in other locations. Results further support biological data indicating that Taiwan Taenia and T. saginata, although similar morphologically, are distinct genotypes.

Animals↗