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Biomedical subjects

H Ham

Publications and source records attributed to H Ham.

71 records · Page 4Linked to original sources
PubMed1989

Brain single photon emission computed tomography in neonates.

This study was designed to rate the clinical value of [123I]iodoamphetamine (IMP) or [99mTc] hexamethyl propylene amine oxyme (HM-PAO) brain single photon emission computed tomography (SPECT) in neonates, especially in those likely to develop cerebral palsy. The results showed that SPECT abnormalities were congruent in most cases with structural lesions demonstrated by ultrasonography. However, mild bilateral ventricular dilatation and bilateral subependymal porencephalic cysts diagnosed by ultrasound were not associated with an abnormal SPECT finding. In contrast, some cortical periventricular and sylvian lesions and all the parasagittal lesions well visualized in SPECT studies were not diagnosed by ultrasound scans. In neonates with subependymal and/or intraventricular hemorrhage the existence of a parenchymal abnormality was only diagnosed by SPECT. These results indicate that [123I]IMP or [99mTc]HM-PAO brain SPECT shows a potential clinical value as the neurodevelopmental outcome is clearly related to the site, the extent, and the number of cerebral lesions. Long-term clinical follow-up is, however, mandatory in order to define which SPECT abnormality is associated with neurologic deficit.

Amphetamines↗
PubMed1989

Regional brain blood flow in congenital dysphasia: studies with technetium-99m HM-PAO SPECT.

Congenital dysphasia is a developmental speech disorder not explained by deafness, phonation disorder, mental retardation, neurologic lesion, or psychiatric disease. The existence of brain lesions has often been postulated but conventional investigations fail to demonstrate any cerebral abnormality. By means of [99mTc]hexamethyl-propyleneamine oxime (HM-PAO) brain single photon emission computed tomography (SPECT) we have studied 14 children suffering from congenital dysphasia. The brain computed tomographic scan was normal in all cases. In two patients with expression impairment the SPECT study demonstrated a hypoperfusion in the inferior frontal convolution of the left hemisphere, involving the Broca's area. In nine of 12 patients with global dysphasia (deficits in both comprehension and expression), SPECT study showed two hypoperfused areas: an abnormality in the left temporoparietal region and a hypoactivity in the upper and middle areas of the right frontal lobe. These results suggest that congenital dysphasia could be due, like acquired aphasia, to specific impairment of the language cerebral areas and that brain SPECT studies with [99mTc]HM-PAO could be useful for a better comprehension of the physiopathology of these disorders.

Aphasia↗
PubMed1988

Unusual ventilation-perfusion patterns in primary lung tuberculosis.

We report two cases of primary lung tuberculosis in children with unusual perfusion ventilation scintigraphic patterns. In the first case, a mismatch in the right upper lobe suggests an elective compression of the bronchi by the mediastinal lymph nodes; in the second case, the total absence of ventilation and perfusion of the left lobe at scintigraphy illustrates the discrepancy sometimes encountered between chest x-ray and lung scintigraphy.

Airway Obstruction↗
PubMed1988

How does salbutamol improve the ventricular performance in patients with chronic obstructive pulmonary disease?

To evaluate the influence of beta 2 mimetics on ventricular contractility and pump function, radionuclide ventriculography and right heart catheterization were simultaneously performed in 10 patients with severe chronic obstructive pulmonary disease. After a 60 min constant infusion of 17 micrograms/min salbutamol, cardiac index increased by 60%, heart rate by 39%, and stroke volume index by 14%. Mean pulmonary artery pressure remained unchanged and mean arterial pressure decreased slightly but not significantly. Right ventricular (RV) function improved as attested to by an increase of RV ejection fraction (+8%), a decrease of RV end-diastolic pressure (-5 mm Hg), and RV end-systolic volume index (-18%). Simultaneously, the pulmonary vascular resistance index decreased by 33% and RV contractility, appreciated by RV dP/dtmax, RV (dP/dtmax)/P, and RV end-systolic pressure/volume ratio, increased by 44, 77, and 27%, respectively. Left ventricular (LV) function also improved. The LV ejection fraction increased by 18% and LV end-systolic volume decreased by 34%. Concomitantly, the systemic vascular resistance index decreased by 40% and the LV end-systolic pressure/volume ratio increased by 50%. Our results suggest that the infusion of salbutamol improves ventricular performance by a decrease of ventricular afterload and by a positive inotropic effect.

Aged↗
PubMed1988

Single photon emission computed tomography in seizure disorders.

Fourteen children with various seizure disorders were studied using a cerebral blood flow tracer, 123I iodoamphetamine (0.05 mCi/kg), and single photon emission computed tomography (SPECT). In the five patients with radiological lesions, SPECT showed congruent or more extensive abnormalities. Five of the nine children with a normal scan on computed tomography had abnormal SPECT studies consisting of focal hypoperfusion, diffuse hemispheric hypoperfusion, multifocal and bilateral hypoperfusion, or focal hyperperfusion. A focal lesion seen on SPECT has been found in children with tonic-clonic seizures suggesting secondarily generalised seizures. Moreover the pattern seen on SPECT seemed to be related to the clinical status. An extensive impairment found on SPECT was associated with a poor evolution in terms of intellectual performance and seizure frequency. Conversely all children with a normal result on SPECT had less than two seizures per year and normal neurological and intellectual development.

Amphetamines↗
PubMed1988

Platypnea induced by worsening of VA/Q inhomogeneity in the sitting position in chronic obstructive lung disease.

We report a patient with COPD who experienced severe dyspnea with a decreased PaO2 in the sitting position, largely improved in the ventral prone position (platypnea). By using an isotopic method, we showed that this phenomenon is the result of a deleterious effect of the sitting position on regional ventilation/perfusion matching. We speculated that hypoxic vascular pulmonary constriction was deficient in our patient. This hypothesis is supported by a dramatically better matching of the VA/Q ratio after treatment with almitrine bismesilate, a drug that could potentiate hypoxic pulmonary vasoconstrictive reflexes.

Aged↗
PubMed1987

Gastric emptying with gastro-oesophageal reflux.

The time taken for gastric emptying of a liquid (milk) or a semi-liquid (pudding) meal was evaluated in 477 infants and children. These patients were referred for suspected gastro-oesophageal reflux and underwent gastro-oesophageal scintigraphy, prolonged oesophageal pH study, manometric evaluation of the lower oesophageal sphincter pressure, and fibreoptic endoscopy. No difference in gastric emptying was observed in children aged under 3 years, regardless of the presence or absence of the gastro-oesophageal reflux, the pressure of the lower oesophageal sphincter, or the presence of oesophagitis. In children over 6 years, however, gastric emptying was significantly delayed in those presenting with reflux compared with those without reflux; in children over 3 years there was slower gastric emptying in those with a decreased lower oesophageal sphincter pressure compared with those with higher pressure and in those with overt oesophagitis compared with those without oesophagitis. This study suggests that gastro-oesophageal reflux is more severe in childhood than in infancy, probably due to more complex motor disorders affecting the gastric fundus as well as lower oesophageal sphincter function.

Adolescent↗
PubMed1986

Dynamic isotopic phlebography using soluble krypton-81m.

Intravenous peripheral injection of krypton-81m in an isotonic solution permits venous scintigraphy of the lower limbs to be carried out. An anatomic definition of the obstructions and the collateral pathways is therefore easily displayed from the popliteal vein to the vena cava. The physical characteristics of the radionuclide permit iterative or sustained perfusions without accumulation of an excessive background noise and the method is used to obtain scintigraphic images in changing physiological conditions. Analysis of the dynamic data permits venous stasis to be assessed in terms of regional radioactivity at a steady state and transit rate. Various physiological and pathological conditions are analyzed by this method.

Hemodynamics↗
PubMed1986

Oesophageal transit patterns in healthy subjects.

Oesophageal transit was studied in 49 healthy volunteers. When a good quality bolus was reached, the tracer passed through the oesophagus leaving no residual activity. The mean time of transit of the total oesophagus was 4.5 +/- 1.3 s. In cases of fragmented bolus, residual activity was found in about 80% of the cases giving rise to a prolonged transit time. When using 81Krm, artefacts due to fragmented bolus can easily be overcome by repeating the test as often as necessary.

Adult↗
PubMed1984

Hemodynamic effects of vasopressin, alone and in combination with nitroprusside, in patients with liver cirrhosis and portal hypertension.

We have investigated the effects on systemic, pulmonary, hepatic, and renal hemodynamics, and on blood gases of vasopressin, 0.4 U/min I.V. first alone, then in combination with nitroprusside 1-5 micrograms/kg/min I.V., in 12 patients with liver cirrhosis and portal hypertension. Portal pressures were estimated by the gradient between occluded and free hepatic vein pressures, hepatic blood flow was measured by indocyanine green infusion, renal blood flow by an isotopic method, and cardiac output by thermodilution. Vasopressin alone reduced cardiac output (-23%) and O2 delivery to the tissues (-25%), increased mean arterial pressure (+20%) and filling pressures of the heart (+136%), reduced portal pressures (-36%) (from 19 +/- 1 to 12 +/- 1 mmHg, mean +/- SEM), hepatic blood flow (-35%) (1.33 +/- 0.2 to 0.87 +/- 0.1 l/min), and renal blood flow (-16%) (0.77 +/- 0.07 to 0.65 +/- 0.05 l/min). Adding nitroprusside restored cardiac output, preload and afterload, and renal blood flow to pretreatment values. Oxygen delivery remained depressed (-12%) because of a negative effect on pulmonary gas exchange (physiologic shunt increased from 16 +/- 2 to 28 +/- 4%). Portal pressures remained reduced by 31% and hepatic blood flow by 25%. These results suggest that small doses of I.V. nitroprusside minimize the deleterious hemodynamic effects of vasopressin while maintaining the therapeutic benefit of portal pressure reduction in cirrhotic patients.

Adult↗
PubMedDate not supplied

[Methodological aspects related to the determination of the relative renal function using 99mTC MAG3].

UNLABELLED: The aim of the study was to evaluate three different methods for calculating the split renal function in patients with only one functioning kidney, keeping in mind that the split function should be zero on the side of the non-functioning kidney. PATIENTS: We retrospectively selected 28 99mTc MAG3 renograms performed in children, 12 with unilateral nephrectomy, 4 with unilateral agenesis and 12 with a non-functioning kidney. METHODS: A renal and perirenal region of interest (ROI) were delineated around the functioning kidney. The ROIs around the empty kidney were drawn symmetrically to the contralateral side. The split renal function was calculated using three different methods, the integral method, the slope method and the Patlak-Rutland algorithm. RESULTS: For the whole group of 28 kidneys as well as for the three categories of patients, the three methods provided a split function on the side of the non-functioning kidney close to the zero value, regardless of whether the empty kidney was the left or the right one. CONCLUSION: We recommend the use of the integral method for the whole range of split renal function with 99mTc MAG3. No significant improvement was obtained by means of the more sophisticated Patlak-Rutland method.

Adolescent↗
PubMedDate not supplied

[Transmission of examination results to patients: opinion of referring physicians and patients].

Patients frequently ask the nuclear medicine physician or the radiologist for conclusions at completion of a diagnostic procedure. The present study tried to assess opinions from both patients and referring physicians. Answers from both parties were grossly discordant: most of the referring physicians thought patients should not be given results of a diagnostic procedure by the nuclearist or radiologist an approach most of the patients disagreed with. Deontological guidelines of the official Belgian association do not authorize nuclear medicine physicians nor radiologists to give the patients any result directly; according to our data, this rule should be adapted.

Adult↗
PubMedDate not supplied

Overview of the clinical usefulness of bone mineral measurements in the prevention of postmenopausal osteoporosis.

Bone mass measurements might be useful in two ways in prevention of postmenopausal osteoporosis: the decision to start HRT, or other therapy, could be based on such measurements; and, possibly, compliance to treatment would be enhanced. Bone density measurement appears to have sufficient predictive value for osteoporotic fracture, especially when density is measured by dual-energy X-ray absorptiometry. However, choice of skeletal site for the measurement cannot be made with certainty, although a vertebral site may be best early in menopause; and in women with osteophytes or scoliosis, and with older women, the femur or wrist may be preferred. With respect to enhancement of patients' compliance to HRT, as well as clinicians' willingness to prescribe treatment, it has not yet been clearly shown that bone mass measurements have a significant effect. This topic involves economic efficiency and should be evaluated by considerations of economics weighted against medical efficacy.

Adult↗
PubMedDate not supplied

Bone mineral content of women with uterine fibromyomas.

OBJECTIVE: To determine if the bone mineral content (BMC) of women suffering from fibroids is different from that of the reference population. DESIGN: Cross-sectional retrospective study. PARTICIPANTS: Fifty-nine women suffering from fibroids, compared to the reference population. OUTCOME MEASURES: BMC was measured at the vertebral L2-L4 site (BMC-1) and at the midradius site (BMC-r). RESULTS: The patients with fibroids exhibited no significant difference in BMC-r). RESULTS: The patients with fibroids exhibited no significant difference in BMC-r, but had a significantly higher (P < or = .001) BMC-1 than the reference population. CONCLUSION: Since BMC-1 is mainly constituted by trabecular bone and BMC-r by cortical bone, and since trabecular bone is more sensitive to estrogens than cortical bone, it is suggested that a hyper-estrogenic state co-existing with fibroids may induce a slight protective factor against osteoporosis of the vertebral skeleton.

Adult↗
PubMedDate not supplied

Laparoscopic Nissen fundoplication: laparoscopic dissection technique and results.

BACKGROUND/AIMS: Proton Pump inhibitors and laparoscopic techniques have had a dramatic impact on the therapy of gastroesophageal reflux disease. These techniques have introduced new complications associated with the treatment. This study compares the results of a laparoscopic Nissen fundoplication with life-long proton pump inhibitor treatment. MATERIALS AND METHODS: Between May 1991 and February 1996, 274 patients were treated by laparoscopic Nissen fundoplication (LNF). Two hundred twenty-four patients were included in this prospective study. Thirteen patients presented stage V esophagitis (Barrett); 4 had esophagitis stage IV; 16 had stage III, 181 had stage II and 11 had stage I. Five trocars were needed for the operation. After mobilization of the greater curvature, a fundic wrap of 5 cm was created and fixed on the esophagus. RESULTS: Median operating time was 60 min (39-300). There were 5 perioperative complications (a gastric perforation, three pleural perforations, and one liver laceration treated by coagulation). Three conversions to laparotomy were necessary. There were 4 early complications: two pulmonary infections and two re-operations; one case of wrap necrosis with peritonitis, and one case of small bowel perforation. Gastroscopy was performed in 133 cases. The esophagus was normal in 121 cases, an esophagitis stage I was present in 9, esophagitis stage II in 2, esophagitis stage III in one. Median lower esophageal sphincter pressure was 10 mmHg (2.9-30) preoperatively and 19 mmHg (9-40) post-operatively. Median reflux time was 10% (0-65) preoperatively and 1% (0-38) post-operatively. One hundred fifty-four patients were interviewed with a median follow up of 30 months (1-58). One hundred thirty patients were Visick I, 11 Visick II, 8 Visick III and 5 patients needed re-operation; three reoperations because of dysphagia, 1 because of epigastric pain and 1 for heartburn recurrence. CONCLUSIONS: From these results, we conclude that LNF seems to be an attractive alternative to long term medical treatment.

Adolescent↗