Acute effect of glyceryl trinitrate on systolic blood pressure and other hemodynamic variables

The acute effect of glyceryl trinitrate (GTN) is mainly the reduction of systolic blood pressure (SBP) rather than diastolic blood pressure (DBP). To examine the mechanisms for decrease in SBP by GTN, the authors measured arterial compliance (AC), cardiac output (CO), stroke volume (SV), pulmonary capillary wedge pressure, right ventricular end-diastolic pressure, right atrial pressure, and left ventricular end-diastolic pressure before and after administration of GTN. Fourteen patients who underwent cardiac catheterization were included in this study. The change of each variable was estimated by the differences between values just before and at three minutes after GTN. After administration of GTN, SBP was significantly decreased from 158 +/- 21 to 138 +/- 12 mmHg (P < 0.01). AC was significantly increased, and pulmonary capillary wedge pressure, CO, and SV were significantly decreased. The change in SBP was inversely correlated with the change in AC and positively correlated with the change in CO or SV. The authors conclude that the mechanism for decrease in SBP by GTN is associated with both an increase in AC and a decrease in venous return.

Clinical evidence for an association between left ventricular geometric adaptation and extracardiac target organ damage in essential hypertension

OBJECTIVES

To elucidate an association between left ventricular geometric adaptation to sustained hypertension and preclinical extracardiac target organ damage in essential hypertension. We also studied the clinical significance of neurohumoral factors for cardiovascular structural changes.

DESIGN

One hundred and forty patients with essential hypertension were divided into four subgroups, based on left ventricular mass index and relative wall thickness. With respect to extracardiac target organ damage, we measured the funduscopic grade of retinal changes and serum creatinine levels.

RESULTS

Among the hypertensive patients, only 19 (14%) had a typical concentric hypertrophy (increase in left ventricular mass index and relative wall thickness). Hypertensive patients with concentric hypertrophy had the most advanced funduscopic abnormalities and the greatest renal involvement, and hypertensive patients without left ventricular hypertrophy had the least extracardiac target organ damage. Plasma renin activity and plasma aldosterone concentration were higher in hypertensive patients with than in those without concentric hypertrophy. In a multiple regression model there was a strongly significant correlation between the degree of left ventricular mass index and the severity of hypertensive retinopathy and renal involvement, independent of office blood pressure.

CONCLUSIONS

These results clearly demonstrate that echocardiographically determined left ventricular mass and geometry stratify extracardiac target organ damage in patients with essential hypertension more closely than office blood pressure. The present study also suggests that, in addition to blood pressure load, the renin-angiotensin-aldosterone system appears to play an important role in myocardial hypertrophy and peripheral vascular damage in hypertension.

A case of familial thyroxine binding globulin excess associated with growth hormone deficiency

A 7 years 3 months old Japanese boy with familial thyroxine binding globulin (TBG) excess associated with growth hormone (GH) deficiency is reported. The patients height was 106.4 cm (-2.86 s.d.) and his bone age was 5 years and 3 months. He had no goiter and his developmental milestones were normal. The serum thyroid stimulating hormone (TSH) was 2.8 microU/mL, triiodothyronine (T3) 3.1 ng/mL, thyroxine (T4) 23.4 micrograms/dL and free T4 1.8 ng/dL. The serum TBG level was beyond 80.0 micrograms/mL, with normal TSH response to the thyrotropin-releasing hormone (TRH) test. Familial study revealed that his grandmother, mother, uncle, younger sister and younger brother had high TBG and T3 levels, thus an X-linked co-dominant transmission was suggested. The peak GH responses to insulin and clonidine hydrochloride were 5.8 and 8.2 ng/mL, respectively. The mean nocturnal GH concentration was 2.5 ng/mL. His growth velocity increased from 4.8 to 8.4 cm/year and his serum TBG levels decreased gradually after human growth hormone (hGH) treatment.

Uncooked cornstarch treatment for hepatic phosphorylase kinase deficiency

A 5-year-old boy with short stature, hepatomegaly and motor weakness due to hepatic phosphorylase kinase deficiency is described. Laboratory data showed mild hypoglycaemia and metabolic acidosis, hepatic dysfunction, and a low insulin-like growth factor-I level. Mild hypoglycaemia, marked ketosis and insufficient growth hormone secretion were revealed at night. Serum total and free carnitine levels were low and the acyl/total carnitine ratio was high. Urinary acylcarnitine profile using fast atom bombardment and tandem mass spectrometry showed increased excretion of acetylcarnitine and dicarboxylylcarnitines. These endocrinological and metabolic abnormalities and clinical symptoms were improved with uncooked cornstarch treatment.

CONCLUSION

Uncooked cornstarch treatment may be helpful in hepatic phosphorylase deficiency.

Diffuse leukodystrophy with a large-scale mitochondrial DNA deletion

An 8-year-old girl with progressive ataxia and bulbar palsy showed diffuse white-matter lesions in the occipital to parietal lobes on magnetic resonance imaging. Since she had slightly elevated lactate in the cerebrospinal fluid, a muscle biopsy was done which revealed scattered ragged-red fibres and focal cytochrome c oxidase deficiency. Southern blot and polymerase-chain-reaction analyses revealed a large-scale mitochondrial DNA deletion, which was 6990 base-pairs in length with 6 base-pair (-TCATCG-) direct repeats at the junctions. Mitochondrial DNA mutation should be considered as one of the candidate causes for diffuse leukodystrophy in children.

Abnormal fatty acid composition of lymphocytes of biotin-deficient rats

The relative proportions (% of total fatty acids) of odd-chain (15:0-29:0) and long-chain (22:0-30:0) saturated fatty acids in phospholipids of biotin-deficient rat lymphocytes were significantly increased as compared with biotin-supplemented rats, and the ratio of unsaturated fatty acids to saturated fatty acids in the former was significantly decreased mainly due to the reduced composition of polyunsaturated fatty acids in the omega-3, omega-6, and omega-9 pathway. The ratio of cis-vaccenic acid to palmitoleic acid in biotin-deficient rats was significantly lower than that in control rats, and was thought to be another important, but previously unreported indicator of biotin deficiency. These changes imply that the elongation and desaturation of unsaturated fatty acids are depressed in lymphocytes of biotin-deficient rats, and may contribute to the associated immunological dysfunction in biotin deficiency through abnormal prostaglandin metabolism and/or cell membrane functions.

Scaphoid megalourethra with multiple urogenital anomalies

A male infant with scaphoid megalourethra, which is a rare congenital anomaly, is presented. At birth he exhibited a grossly swollen, malformed penis and cryptorchidism. The corpus spongiosum was not palpable. The infant had congenital renal failure. Retrograde urethrography revealed a crescent-shaped dilatation of the anterior urethra, and the diagnosis of scaphoid megalourethra was made. Subsequent uroradiological examinations showed that there were also severe urogenital anomalies, i.e. renal hypoplasia-dysplasia, hydronephrosis, hydroureter and vesicoureteral reflux. This disorder is frequently associated with other urogenital anomalies. Therefore, once the diagnosis is reached, a careful investigation for other associated abnormalities should be undertaken.

cDNA sequences encoding human fructose 1,6-bisphosphatase from monocytes, liver and kidney: application of monocytes to molecular analysis of human fructose 1,6-bisphosphatase deficiency

Fructose 1,6-bisphosphatase deficiency is an autosomal recessive inherited disorder of gluconeogenesis. We could isolate cDNAs encoding human fructose 1,6-bisphosphatase from normal monocytes, liver and kidney, but not from normal lymphocytes. The cDNAs contained an open reading frame coding for 338 amino acids, and their nucleotide sequences in monocytes and liver were identical. G644C645 nucleotides in this sequence were the same as those of cDNA from HL-60 cells, although our result differed from a previous report (M. El-Maghrabi et al. (1993) J. Biol. Chem. 268, 9466-9472) on an alteration to C644G645 nucleotides in human liver cDNA resulting in a change of Gly-214 to Ala-214 in the enzyme. The Gly-214 (GGC) residue was therefore conserved in the enzymes hitherto isolated from humans and other animals. Analysis of monocytes in seven patients with fructose 1,6-bisphosphatase deficiency showed a DNA fragment with apparent normal size in two sisters but no detectable DNA fragment in the other five patients. Monocytes were thus useful as an alternative source for mRNA from human liver for the molecular analysis of fructose 1,6-bisphosphatase deficiency.

Accurate diagnosis of metastatic cardiac leiomyosarcoma with infundibular stenosis and cardiac tamponade by transesophageal echocardiography and Gd-DTPA magnetic resonance imaging--report of a case

We present a patient with metastatic cardiac leiomyosarcoma that was diagnosed antemortem by transesophageal echocardiography (TEE) and ECG-gated magnetic resonance imaging with gadolinium diethylene triaminepentaacetic acid (Gd-DTPA MRI). TEE and Gd-DTPA MRI clearly revealed the morphological characteristics of infundibular stenosis and cardiac tamponade. Our patient has survived about 30 months after cardiac surgery. Since sarcoma is usually associated with a very poor prognosis, surgical treatment should be performed as soon as possible. TEE with color Doppler imaging and Gd-DTPA MRI are very useful diagnostic methods for determining the precise anatomical characterization of cardiac tumor, and these procedures are prerequisite to precise therapy.

[Intra-ventricular pressure gradient and systolic anterior movement of the mitral valve associated with administration of dopamine in a 91-year-old patient]

A 91-year-old woman had decreased systemic blood pressure accompanied by dyspnea and general fatigue after resection of a face tumor (Merkel cell carcinoma). Dopamine was administered to elevate systemic blood pressure, but it did not sufficiently restore the hemodynamic status. Left ventricular apical aneurysm was observed on echocardiogram. Furthermore, SAM (systolic anterior movement of the mitral valve) was observed on M-mode echocardiogram and a pressure gradient of 34.6 mmHg in the midventricular position was confirmed by continuous wave Doppler using the Bernoulli equation. After volume overload and discontinuation of dopamine, SAM completely disappeared and midventricular pressure gradient markedly decreased. Her general condition improved. Because of the narrowed outflow tract, hypercontractile state induced by beta adrenergic stimulation seemed to be one of the important factors for the genesis of SAM and pressure gradient.

Evaluation of acute myocarditis and pericarditis by Gd-DTPA enhanced magnetic resonance imaging

Gd-DTPA enhanced magnetic resonance imaging was performed in two adult patients with acute myocarditis and pericarditis. Gd-DTPA enhancement seemed to identify the exact cardiac region with the higher degree of inflammation.

Myocardial scintigraphic characteristics in patients with primary aldosteronism

To evaluate the difference in myocardial damage between primary aldosteronism and untreated essential hypertension, we performed thallium-201 myocardial single-photon emission computed tomography in 10 patients with primary aldosteronism and 10 patients with essential hypertension who were matched for age, sex, blood pressure, and the severity of left ventricular hypertrophy for primary aldosteronism. From the analysis of thallium-201 myocardial scintigraphy, extent score was calculated. Extent score was significantly higher in primary aldosteronism than in essential hypertension (45.8 +/- 23.5% versus 9.5 +/- 7.3%, P < .01). After operation, blood pressure significantly decreased, and the precordial voltages (SV1 + RV5) and left ventricular mass indexes were significantly reduced in patients with primary aldosteronism. Extent score was also significantly improved. These results suggest that despite the same severity of myocardial hypertrophy between primary aldosteronism and essential hypertension, the myocardial damage estimated by thallium-201 myocardial scintigraphy is more severe in primary aldosteronism than in essential hypertension. Extent score was useful for evaluation of the severity of myocardial damage in hypertensive patients.

Adenosine 5'-triphosphate, phorbol ester, and pertussis toxin effects on atrial natriuretic peptide stimulation of guanylate cyclase in a human renal cell line

We examined adenosine 5'-triphosphate (ATP), pertussis toxin (PT) and phorbol myristate acetate (PMA), a protein kinase C (PKC) activator, modulation of atrial natriuretic peptide (ANP)-stimulated cell-membrane guanylate cyclase (ANP-s-GC) activity and ANP stimulation of whole-cell cGMP accumulation (ANP-s-cGMP) in an ANP-receptor-transduction cell model, the human renal cell line (SK-NEP-1). Acute and long-term effects of PMA on PKC isotype activity are different: Acute (20-min) PMA activation of PKC inhibits ANP-s-cGMP and ANP-s-GC; whereas, long-term (36-h) PMA treatment inhibits slightly less by only partially down-regulating PKC activity, the type-III PKC isotype being 36-h resistant. Long-term 10(-7)M PMA treatment of cells neither affected membrane basal GC activity nor ANP-s-GC activity but partially inhibited ATP enhancement of ANP-s-GC. This partial inhibition was completely reversed by the PKC inhibitor H7 and a PKC inhibitory antibody but only partially reversed by the antibody to the catalytic domain of PKC type III. The EC50 for ATP and its non-phosphorylating analog ATP gamma S in the presence of acute PMA inhibition of ANP-s-cGMP was similar (approximately 10(-9)). This enhancement of PMA inhibition was two orders of magnitude more sensitive (EC50 10(-7)M) than inhibition of ANP-s-cGMP that we previously reported for acute PMA treatment of whole SK-NEP-1 cells. The three- to four-fold ATP enhancement of cell membrane ANP-s-GC was not blocked by 12-hour preincubation of cells with 150 ng/mL PT but was completely blocked if 2-x-10(-7)M PMA was then added for 20 minutes, indicating that acute activation of PKC by PMA does not require a functional "G-type" protein. Acute PMA inhibition of ANP-s-cGMP was reversed by permeabilizing SK-NEP-1 cells to a specific PKC inhibitory peptide, further confirming that PMA inhibition was mediated through PKC activation. These data demonstrated that ANP-s-GC and ANP-s-cGMP were modified through non-phosphorylating interactions with ATP, by multiple PMA activatable PKC isoforms, and that neither were affected by PT-sensitive guanine-nucleotide-binding (G)-protein(s).

Acylcarnitine profile in tissues and body fluids of biotin-deficient rats with and without L-carnitine supplementation

Since biotin-deficient (BD) rats are a good animal model for human multiple carboxylase deficiency and have low plasma free carnitine levels, short-chain acylcarnitine profiles in biotin-deficient rats with L-carnitine supplementation (BDC rats) and BD rats were investigated by fast-atom bombardment and tandem mass spectrometry and gas chromatography/mass spectrometry. By the latter method, 3-hydroxyisovalerylcarnitine was identified in BD rats, and showed the greatest accumulation among short-chain acylcarnitines in tissues of BD rats, while the tissue levels of propionic acid were more markedly elevated than those of 3-hydroxyisovaleric acid. The tissue levels of 3-hydroxyisovaleryl-carnitine were significantly lower and those of propionyl-carnitine were somewhat higher in BDC rats than in BD rats, while the tissue levels of propionic acid and 3-hydroxyisovaleric acid in BDC rats were lower than those in BD rats. These changes were more apparent in kidney than in other tissues. The amounts of urinary excretion of acylcarnitines were markedly larger, and those of 3-hydroxyisovaleric acid were somewhat smaller in BDC rats than in BD rats, while those of propionic acid were very low in BD and BDC rats as compared with those of 3-hydroxyisovaleric acid. It seems that the relationship between the concentrations of 3-hydroxyisovalerylcarnitine and those of propionylcarnitine reflects the unique metabolism of the related metabolites in tissues, especially in kidney, which may be influenced by their urinary excretion and the availability of free carnitine. These data in biotin deficiency suggest that carnitine supplementation is possibly beneficial for patients with holocarboxylase synthetase deficiency who respond incompletely to biotin therapy.

Effects of glyceryl trinitrate on blood pressure and arterial compliance

Glyceryl trinitrate (GTN) mainly reduces systolic blood pressure (SBP) rather than diastolic blood pressure (DBP) in acute conditions. To examine the efficacy of GTN as an antihypertensive agent in patients with isolated systolic hypertension (ISH), the authors examined the effects of GTN on BP and arterial compliance (AC) in patients who underwent cardiac catheterization. Seventy patients (with old myocardial infarction, 36; angina pectoris, 25; chest pain syndrome, 9) who underwent cardiac catheterization because of chest pain were included in this study. They were aged between thirty-seven and seventy-four (mean sixty-one) years. According to the levels of BP at cardiac catheterization, the authors selected two subgroups: the normotensive group (NT group, n = 18) and the isolated systolic hypertensive group (ISH group, n = 20) from all subjects. The authors measured BP before and after (three minutes) sublingual administration of GTN (0.3 mg) at the cardiac catheterization. AC was assessed by means of diastolic pressure decay. The change of BP was estimated by the differences between values before and at three minutes after GTN. After administration of GTN, SBP was decreased significantly from 157 +/- 25 to 142 +/- 23 mmHg (P < 0.01), while DBP did not change (83 +/- 13 vs 84 +/- 15 mmHg). The change in SBP was positively correlated with the pretreatment SBP and negatively correlated with AC (r = 0.51, P < 0.001; r = 0.39, P < 0.001, respectively). AC was significantly lower in the ISH group than in the NT group (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Precise assessment of myocardial damage associated with secondary cardiomyopathies by use of Gd-DTPA-enhanced magnetic resonance imaging

To evaluate the myocardial damage in patients with secondary cardiomyopathies, the authors examined gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA)-enhanced magnetic resonance imaging (MRI) in 5 patients (2 with cardiac amyloidosis, 2 with acute myocarditis, 1 with cardiac thyrotoxicosis). MR images were performed at 1.5-T by using a spin echo pulse sequence before and after intravenous administration of Gd-DTPA (0.2 mmol/kg). All patients revealed distinct high-intensity areas on postcontrast images. Moreover, MRI with Gd-DTPA could determine the severity and precise regions of myocardial damage associated with secondary cardiomyopathies. It is suggested that gated cardiac MRI with Gd-DTPA enhancement is useful for detecting the myocardial damage in secondary cardiomyopathies.

The effects of biotin deficiency on organic acid metabolism: increase in propionyl coenzyme A-related organic acids in biotin-deficient rats

Volatile organic acid levels in plasma and tissues and nonvolatile organic acid levels in urine of biotin-deficient (BD) rats were measured and compared with other factors of biotin deficiency. Biotin levels and the activities of propionyl coenzyme A (CoA) carboxylase (PCC) in the livers of these rats were decreased, respectively, to 22% +/- 3% and 3.6% +/- 0.3% of the average values of pair-fed controls. Plasma concentrations of propionate were higher (15 to 223 micrograms/mL) than those of controls (5 to 7 micrograms/mL), whereas plasma levels of 3-methylcrotonate were only minimally increased as compared with those of controls. Concentrations of these volatile acids in the tissues were similarly increased, although those in brain showed less remarkable increases as compared with levels in other tissues. In the urine of BD rats, large amounts of organic acids derived from propionyl CoA, as well as those from 3-methylcrotonyl CoA, were excreted. Plasma propionate levels were not apparently related to the severity of clinical symptoms, biotin levels, or carboxylase activities, but were related to the amounts of urinary ketone bodies, lactate, and some of the organic acids derived from branched-chain amino acids, including those from propionyl CoA.

Atrial natriuretic peptide and left atrial systolic function in normal subjects

The purpose of this study is to elucidate factors determining the release of atrial natriuretic peptide (ANP) in normal volunteers at rest. Ten normal volunteers were included in this study. Ages ranged between twenty-seven and thirty-three years (mean twenty-seven). The authors measured plasma levels of ANP, and four cardiac chamber volumes, and their functions by cine magnetic resonance imaging using the rephased gradient-echo method. Plasma levels of ANP in 10 normal subjects were 15.0-37.1 pg/mL (mean 23.6 pg/mL). No significant relationship was seen between ANP level and heart rate or blood pressure. The level of ANP was positively correlated with left atrial (LA) emptying fraction and negatively correlated with LA minimal volume (r = 0.85, P < 0.01; r = 0.64, P < 0.05, respectively). No significant relationship was observed between plasma ANP level and left ventricular, right ventricular, or right atrial parameters. These results suggest that LA systolic function is one of the major determinants for ANP release in normal subjects at rest.

A long-term suppression by alpha-interferon of Philadelphia chromosome in children with chronic myelogenous leukemia

An 8 year old girl with adult type Philadelphia (Ph1)-positive chronic myelogenous leukemia received natural alpha-interferon therapy in the chronic phase. Complete suppression of the Ph1 clone of bone marrow cells was achieved after 1 month of therapy, which was determined by disappearance of rearranged breakpoint cluster region (BCR) gene in Southern blot analysis. Complete hematological remission was also attained following 2 months of therapy. Both the suppression and the hematological remission have been sustained for 24 months with alpha-interferon, in spite of the detection of the chimeric BCR/ABL mRNA in her bone marrow by polymerase chain reaction assay 12 months after therapy.

Detection of heterozygotes for fructose-1,6-diphosphatase deficiency by measuring fructose-1,6-diphosphatase activity in monocytes cultured with calcitriol

The increase of fructose-1,6-diphosphatase activity during culture with calcitriol, which was reported in monocytes, was found not to occur in lymphocytes. Monocytes cultured with calcitriol were accordingly used as more reliable diagnosis of heterozygotes for fructose-1,6-diphosphatase deficiency, instead of mononuclear cells (lymphocyte-fraction-containing monocytes) cultured without calcitriol by a conventional method. Variation of fructose-1,6-diphosphatase values in leukocytes from nine healthy adults was smallest in monocytes cultured with calcitriol, among four different experimental conditions: monocytes cultured with or without calcitriol and mononuclear cells cultured with or without calcitriol. Both parents of two sisters with fructose-1,6-diphosphatase deficiency were successfully confirmed as carriers of fructose-1,6-diphosphatase deficiency by this method. However, confirmation by the conventional method using mononuclear cells cultured without calcitriol was possible only in the father, not in the mother. Thus, the new method using monocytes cultured with calcitriol seems more reliable for detecting heterozygotes for fructose-1,6-diphosphatase deficiency.

Different ATP effects on natriuretic peptide receptor subtypes in LLC-PK1 and NIH-3T3 cells

We have observed different ATP interactions in two guanylate cyclase (GC)-coupled natriuretic peptide (NP) receptor subtypes, designated NPR-A and NPR-B. The NPR-A is selectively expressed by LLC-PK1 epithelial cells and the NPR-B by NIH-3T3 fibroblast cells. In LLC-PK1 membranes, ATP-Mg2+ potentiated ANP-stimulated GC activity (ANP-s-GC). In contrast, in NIH-3T3 membranes, ATP-Mg2+ inhibited ANP-s-GC but enhanced CNP-stimulated GC activity (CNP-s GC). ATP in the presence of Mn2+ inhibited LLC-PK1 and NIH-3T3 membrane ANP-s-GC and CNP-s-GC. These are the first data suggesting that the ATP-Mg2+ produces different effects between membrane NPR-A and -B subtypes. We have also demonstrated that GC of NPR-B is sensitive to methylene blue.

Urinary sugar phosphates and related organic acids in fructose-1,6-diphosphatase deficiency

Two sisters with fructose-1,6-diphosphatase deficiency are reported. They presented with ketonuria, elevated plasma transaminase activity and severe metabolic acidosis during hypoglycaemic crises, which resembled Reye syndrome. Intravenous fructose tolerance tests provoked severe hypoglycaemia and metabolic acidosis. Fructose-1,6-diphosphatase activities in both peripheral leukocytes and cultured lymphocytes were below the limit of detection. Urinary organic acid analysis during crises revealed markedly increased excretion of lactate, ketone bodies, glycerol and glycerol-3-phosphate. We newly identified other glycolytic intermediates, glyceraldehyde, 3-phosphoglycerate and fructose-1,6-diphosphate, in the urine during hypoglycaemic attacks or after fructose tolerance tests. Identification of such compounds may be useful in the early diagnosis of this disease.