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Biomedical subjects

G T Strickland

Publications and source records attributed to G T Strickland.

At least 19 recordsLinked to original sources
PubMed1992

Ultrasound for detecting Schistosoma haematobium urinary tract complications: comparison with radiographic procedures.

Chronic infection with Schistosoma haematobium primarily causes urinary tract complications. These lesions are often silent or ignored and not detected until irreversible changes have occurred. However, early chemotherapy can prevent progression and usually reverse all but the more severe abnormalities. Recently, abdominal ultrasound has been shown to be an inexpensive, portable and safe means of detecting schistosomal morbidity. A prospective study was performed on 40 patients comparing abdominal radiography, excretory urography (IVP), cystoscopy and ultrasound to detect urinary tract morbidity due to S. haematobium infection. Ultrasound was as sensitive as an IVP in detecting bladder masses, hydronephrosis and renal stones. It detected hydroureter less frequently (sensitivity 62.5%) than an IVP but visualized this lesion and hydronephrosis in some patients with nonfunctioning kidneys. Ultrasound demonstrated bladder stones as well as an x-ray but it detected bladder wall calcification with less sensitivity (65%) and was much less sensitive (12.5%) for detecting ureteral stones.

Adult↗
PubMed1992

Fever in the returned traveler.

Febrile infections can be fatal in travelers to tropical countries unless the patient seeks medical care in a timely manner and the physician takes the time and has the skill to make a rapid diagnosis and prescribe appropriate therapy. In addition to the usual febrile illnesses present in temperate climates, the patient may have an "exotic" infection, e.g., malaria, infectious hepatitis, enteric fever, or dengue fever. The potential causes of fever in travelers are extensive. This article provides practical clues to assist the physician in making the correct diagnosis--by using exposure information, symptoms and signs, and concomitant symptom complexes.

Diarrhea↗
PubMed1992

Efficacy of hepatitis B vaccination in primary school children from a village endemic for Schistosoma mansoni.

To determine whether chronic Schistosoma mansoni infection interferes with hepatitis B virus (HBV) immunization, 308 schoolchildren aged 6-12 years with no evidence of prior HBV infection (156 with active schistosomiasis) were vaccinated with three 5-micrograms injections of recombinant DNA-derived HBV vaccine. The vaccine was given in the deltoid muscle at time 0 and 1 and 7 months later. All vaccinees were examined 1 and 3 years after vaccination for quantitative antibody to hepatitis B surface antigen (anti-HBs). Seroconversion was detected in 284 vaccinated children (92%), of whom 271 had a good (51-300 mIU/mL) or excellent (greater than 300 mIU/mL) anti-HBs response. Sixteen other children (5%) had evidence of natural HBV infection (antibody to hepatitis B core antigen). Of those with good or excellent response, 99% retained high antibody titers for 3 years. Response was not influenced by S. mansoni infection. Hepatomegaly and splenomegaly were associated with reduced vaccine response.

Child↗
PubMed1992

Grading of hepatic schistosomiasis by the use of ultrasonography.

Forty-three subjects with pure hepatic schistosomiasis having ultrasonographic assessment of periportal fibrosis were grouped according to the thickness of their portal tracts: grade I = 3-5 mm, grade II = greater than 5-7 mm, and grade III = greater than 7 mm. A history of hematemesis, blood transfusion, sclerotherapy, and lower limb edema correlated with the ultrasonographic grade of periportal fibrosis. With increasing grade, the average liver size was smaller and the average spleen size was larger, as determined by physical examination and by ultrasonography. Abnormalities in serum enzyme levels were more frequent in those with thicker portal tracts. Greater diameters of the portal and splenic veins and ultrasonographically detectable collateral blood vessels were associated with increasing thickness of portal tracts. The grade of endoscopically determined esophageal varices was highly correlated with the grade of periportal fibrosis. We concluded that this method of grading accurately reflects the hemodynamic changes and provides a good estimate of the clinical status of patients who have periportal fibrosis due to schistosomiasis mansoni. Where available, it should replace clinical grading based upon the liver and spleen size as detected by physical examination.

Adult↗
PubMed1992

Ultrasonographic changes of the liver in Schistosoma haematobium infection.

Abdominal ultrasonographic examination was performed in 61 hospitalized patients with chronic liver diseases and 253 school children from a village endemic for Schistosoma haematobium and were compared with 142 urban children without exposure to Schistosoma. The prevalence of ultrasound-detectable hepatomegaly and splenomegaly and the degree of periportal fibrosis was compared between those with and without S. haematobium infection. Among 13 patients with biopsy-proven schistosomal hepatic fibrosis, three with coarse changes secondary to S. mansoni infection showed grade III periportal fibrosis, while 10 patients with fine schistosomal hepatic fibrosis due to S. haematobium had borderline (two) or grade I (eight) changes. Ultrasound evidence of periportal fibrosis was not detected in patients with hepatic cirrhosis, chronic active hepatitis, or fatty infiltration. However, three of 14 patients with chronic persistent hepatitis had grade I periportal fibrosis and two had borderline changes. The frequency of ultrasound-detected hepatomegaly and splenomegaly was greater among rural S. haematobium-infected children (35.2% and 22.4%, respectively) than among noninfected rural (21.1% and 13.3%) and urban (16.9% and 4.9%) children. Also, the frequency of grade I periportal fibrosis was significantly greater (P less than 0.01) in S. haematobium-infected children (22.4%) than in noninfected rural (11.7%) and urban (0.7%) children. No patients with S. haematobium infections, either in the hospital or the village, had grade II or III periportal fibrosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Biopsy↗
PubMed1992

Tuberculous peritonitis in Egypt: the value of laparoscopy in diagnosis.

Abdominal laparoscopy was performed on 200 patients with undiagnosed ascites. It was unsuccessful in one patient with tuberculous peritonitis because of extensive adhesions. A presumptive diagnosis of tuberculous peritonitis based on clinical findings and peritoneal tubercles or adhesions visualized during laparoscopy was made in 90 of these patients. The diagnosis was confirmed in 88 by histopathology, bacteriology, or therapeutic response. Two of the 109 remaining patients who had other presumptive diagnoses made during laparoscopy were eventually confirmed to be cases of tuberculous peritonitis. Of 91 patients with tuberculous peritonitis included in this series, 79% were females, with the majority (79%) of them being of child-bearing age. Half had been ill for longer than one month. The most frequent complaints were abdominal pain, fever, anorexia, night sweats, abdominal swelling, and weight loss. Ascites, fever, wasting, pallor, and abdominal tenderness were common findings. Ultrasonography demonstrated ascites in all patients who underwent this procedure; 21% also had adhesions. Pleural effusion was present in 15% and pulmonary tuberculosis was detected in only two patients. Biopsy samples taken during laparoscopy showed that 60% had noncaseous granulomas and 33% had caseous granulomas. Mycobacterium tuberculosis was detected in 77%, with guinea pig inoculation having the highest sensitivity, followed by culture, and lastly by acid-fast smear. Mycobacterium tuberculosis was isolated more easily from biopsy samples than from ascitic fluid. Nine of 20 M. tuberculosis isolates that were identified as to species were M. bovis. Tuberculous peritonitis, a frequent cause of febrile ascites in Egyptian women, was easily diagnosed by histopathologic and bacteriologic studies of biopsy samples taken at laparoscopy. All patients responded rapidly to antituberculosis therapy.

Adolescent↗
PubMed1991

The impact of endemic schistosomiasis on acute viral hepatitis.

One hundred forty-four of 166 adults with acute viral hepatitis (AVH) admitted to an Egyptian fever hospital were followed for 12 months. The hepatitis B surface antigen (HBsAg) carrier rate in 95 with hepatitis B virus (HBV) hepatitis decreased from 53% at three months to 13% at 12 months. At 12 months, 22% of the male patients had persistent HBsAg compared with only 7% of the female patients. The HBsAg carrier rate was 25% at 12 months in those with schistosomiasis compared with 9% in those with only acute HBV infection. Splenomegaly persisted in those with palpable spleens at the initial examination and others developed splenomegaly. The prevalence of splenomegaly increased from 11% on admission to 20% at 12 months in those with only AVH, and from 40% to 69% in those with concomitant schistosomiasis. Patients with concomitant schistosomiasis had higher mean values for liver function test results and a greater proportion had abnormal liver function test results during hospitalization and follow-up than those with AVH only. Concomitant schistosomiasis increased the prevalence and prolonged splenomegaly and morbidity due to AVH. Both male sex and concomitant schistosomiasis prolonged the HBsAg carrier state. We propose that AVH frequently converts uncomplicated intestinal schistosomiasis to hepatosplenic schistosomiasis.

Acute Disease↗
PubMed1990

Delayed-type hypersensitivity and protection in mice following immunization with Plasmodium berghei sporozoites.

The measurement of footpad swelling (FPS) following the inoculation of sporozoite antigen (Ag) into the hind footpad (HFP) of outbred mice was used as an in vivo test of delayed-type hypersensitivity (DTH) to attenuated sporozoite immunization. An attempt was made to correlate DTH with protective antisporozoite immunity. The optimum time for testing DTH following a single intravenous immunization was four days. The optimum sensitizing dose was 1 x 10(5) attenuated sporozoites. A single immunization gave a greater FPS than multiple immunizations. Mice immunized with irradiation-attenuated sporozoites could be protected from a lethal challenge with nonattenuated sporozoites. The FPS response to mosquito debris Ag was minimal in mice sensitized by bites from infected mosquitos. Nude mice failed to develop an FPS response and could not mount a protective immunity with attenuated sporozoites. However, splenectomized mice did have an FPS response following sensitization. Mice infected with blood-stage parasites had negligible FPS response to sporozoite Ag. The FPS response to sporozoite Ag proved to be a correlate of DTH in mice sensitized with sporozoites.

Animals↗
PubMed1989

Characteristic sonographic pattern of schistosomal hepatic fibrosis.

The hepatic sonographic patterns from 50 patients undergoing operations for bleeding esophageal varices were compared with the interpretation of the histological findings in a hepatic wedge biopsy obtained during surgery. The sonographic pattern for schistosomiasis periportal fibrosis is characteristic and is not mimicked by other hepatic diseases we have studied. Sonography agreed with pathology in 44 out of 50 patients. Schistosomiasis could be separated from cirrhosis, as well as from combined lesions. Where there was a discordance, we believe that sonography gave a more accurate diagnosis.

Adult↗
PubMed1989

Ultrasonographic resolution time for amebic liver abscess.

Hepatic ultrasonography not only can be used to detect amebic liver abscess, but can follow its resolution. Twenty-five patients with 32 abscesses had hepatic sonography performed repeatedly. Sonography clearly demonstrated abscesses of 1-22 cm; 19 patients (76%) had abscesses only in the right lobe of the liver, and 22 (88%) had solitary abscesses. Resolution time ranged from 2 months for the smallest abscess to 20 months for the largest. Four abscesses initially had a heterogenous partially solidified pattern. All abscesses healed completely, leaving normal hepatic sonographic patterns.

Adolescent↗
PubMed1988

Circulating antigens for assessing cure in schistosomiasis mansoni.

An antigen capture enzyme-linked immunosorbent assay using antibodies made in rabbits and sheep to adult Schistosoma mansoni extract antigens has been developed and evaluated as a diagnostic test for schistosomiasis. 25 of 42 patients with S. mansoni infections had detectable circulating antigen while sera from all of 45 normal subjects and patients with other parasitic infections did not react. When the 25 with antigenaemia were retested 3 months after treatment, all 21 who were cured were negative while the 4 with persisting S. mansoni eggs in their stools remained positive. Antibodies to a fractionated egg antigen (CEF6) also diminished in most patients following successful treatment, but the reduction was insufficient to predict successful therapy.

Adolescent↗
PubMed1988

Malaria and splenomegaly in the Punjab.

Splenomegaly and parasitaemia were correlated in 2891 children examined in outpatient clinics during 13 consecutive months in 4 Punjabi villages. The average monthly splenomegaly rate varied from 0.05-0.13 before the monsoon malaria transmission season to 0.18-0.27 during and after this season. Moderate splenic enlargement reached a peak during the malaria transmission season, while the highest proportion of very enlarged spleens occurred towards the end of, and after, the transmission season. Children with splenomegaly were 3 times more likely to have Plasmodium falciparum and 1.5 times more likely to have P. vivax parasitaemias than were children without palpable spleens. The larger the spleen the more likely a P. falciparum infection, whereas P. vivax was more commonly associated with minimal spleen enlargement. Although the probability of a child with splenomegaly having a malaria parasitaemia was highest (0.58-0.72) during and immediately following periods of malaria transmission, the odds ratio of malaria infections among those with splenomegaly to those without was at its lowest (1.41-2.11) during those months. Mean P. falciparum parasitaemias were significantly higher in infected children with moderately enlarged spleens than in infected children with nonpalpable spleens or in those with minimal or extensive splenomegaly. These results are compatible with splenomegaly being a result of both the malaria infection and the immune response. Early in infection many children had parasitaemia without splenomegaly; after the parasitaemia had cleared splenomegaly often persisted.

Age Factors↗
PubMed1987

Endemic malaria in four villages of the Pakistani province of Punjab.

The prevalence of malaria in 4 villages 60 km south of Lahore, Punjab, where Anopheles culicifacies is the vector was estimated from blood films made during three mass malaria surveys (MS) and at 204 clinics (CS) held over 18 consecutive months. The highest parasite rate occurred during October 1984 when 43% of the CS population had parasitaemias. Plasmodium vivax predominated early in the major transmission season (23% and 15% vivax parasitaemias in August 1983 and 1984 respectively) whereas P. falciparum was the most common species later in the transmission season (an average falciparum prevalence of 37% in October and November 1984) and following the transmission season through March. Despite the proximity and habitat similarity of the 4 villages, both total and species malaria prevalence rates showed inter-village differences. Asexual stage and gametocyte parasite rates in children were 2 to 5 times higher than in adults. No increased mortality due to malaria was detected among the 4000 study population. Malaria was stable and endemic, albeit seasonally transmitted, in these 4 villages during 1983 and 1984.

Adolescent↗
PubMed1987

Reliable assessment of malaria prevalence through village clinics.

In 4 villages in the Pakistani Punjab, clinic surveys (CS) provided similar results on total malaria and malaria species prevalence as those from mass surveys (MS)--and at a fraction of the effort. This was true at 3 different levels of malaria transmission. Both methods requiring blood films from all interviewed subjects are believed to be superior to the classical active (ACD) and passive (PCD) case detection methods which sample only patients with a history of recent fever. These latter methods would not detect the large population of oligo- and asymptomatic parasitaemic subjects in the semi-immune population of malaria endemic areas.

Adolescent↗
PubMed1987

Amodiaquine fails to cure chloroquine resistant Plasmodium falciparum in the Punjab.

We evaluated amodiaquine as a replacement drug for treating falciparum malaria in an area of Pakistani Punjab where chloroquine-resistant Plasmodium falciparum has recently emerged. Amodiaquine appeared to be 4 to 8 times more effective than chloroquine when P. falciparum isolates were tested in vitro. However, the recrudescence rate was greater than 50% after oral treatment with 20 mg/kg amodiaquine given over two successive days. This lack of therapeutic response from amodiaquine may have been due to selection of resistant parasites in the villages where the study was performed through extensive use of chloroquine for presumptive malaria treatment during the preceding 18 months. We conclude that amodiaquine is not a suitable replacement for chloroquine for treating falciparum malaria in our study area despite in vitro sensitivity data suggesting that it would be efficacious. Baseline in vitro sensitivity to mefloquine is also reported.

Amodiaquine↗
PubMed1986

Effects of chloroquine, amodiaquine and pyrimethamine-sulfadoxine on Plasmodium falciparum gametocytemia.

The effects of chloroquine, amodiaquine and pyrimethamine-sulfadoxine (SP) (Fansidar) on the infection rate and density of Plasmodium falciparum gametocytes were studied in 198 patients with falciparum malaria from an area in the Punjab where malaria is endemic but seasonally transmitted. One month following treatment of 100 patients, SP had reduced the gametocyte carrier rate from 37% to 6% and the mean gametocyte density from 80 to 1.4 per mm3 of blood. Chloroquine and amodiaquine were much less effective. Since SP has no gametocytocidal properties and the reduction in gametocytes coincided with clearance of asexual parasitemias, gametocytes were probably reduced subsequent to the cure of the asexual malaria infections. If used during the nontransmission season, SP might be an effective component of an integrated program for reducing malaria transmission in the Punjab and other areas where 4-aminoquinoline-resistant and SP-sensitive falciparum malaria exists.

Adolescent↗
PubMed1986

Effects of Fansidar on chloroquine-resistant Plasmodium falciparum in Pakistan.

Fansidar (SP), a combination of sulfadoxine and pyrimethamine, was evaluated for its usefulness as a curative agent for treating individual malaria patients and for reducing the community reservoir of Plasmodium falciparum in 4 villages near Lahore, Pakistan, where resistance of 4-aminoquinolines has recently been reported. Following the end of the major malaria transmission season, we carried out a month-long mass treatment campaign during which SP was given to all available villagers who had parasitemias detected during a concurrent house-to-house malaria blood film survey. Of the 82 falciparum patients followed for 14 days after SP treatment, 80 (97.5%) had parasites sensitive to the investigated drug. Parasitemia clearance time after SP was remarkedly short (1.25 +/- 0.53 days; mean +/- SD). However, we were unable to reduce the parasite reservoir of P. falciparum and P. vivax in these villages, probably because we treated only 337, about one-third, of the parasitemic patients. We conclude that SP is an effective drug for treating individual malaria patients from areas in Pakistan where 4-aminoquinoline-resistant parasites are present, but that more research is needed for assessing its usefulness in reducing community reservoirs of malaria.

Disease Reservoirs↗