Pathophysiology and end-organ damage in elderly hypertensives

PATHOPHYSIOLOGY OF HYPERTENSION: Blood pressure increases with advancing age in most developed countries. The pathophysiology of elderly hypertension is characterized by changes in the structure and function of the cardiovascular system. Changes in arterial structure lead to a decrease in aortic compliance, which augments the aortic pressure component generated by the wave reflection mechanism. The age-related increase in the reflected-wave component of arterial pressure may contribute, at least in part, to the age-related rise in systolic blood pressure. Disproportionately elevated systolic blood pressure in the elderly may account for the progressive increase in left ventricular mass with advancing age. In addition to the changes in vascular and cardiac structures, the haemodynamic function of elderly hypertensives is characterized by increased peripheral resistance as well as reduced cardiac output, renal blood flow and intravascular volume. In contrast to younger hypertensives, the sympathetic and renin-angiotensin systems may not be major factors in the genesis of high peripheral resistance in this patient group. END-ORGAN DAMAGE: The most important end-organ damage in elderly hypertensives is left ventricular hypertrophy with or without coronary heart disease, cerebrovascular disease or renal impairment. Furthermore, this end-organ damage is frequently asymptomatic (silent). The prevalence of silent cerebrovascular disease in particular is surprisingly high in this elderly population. Asymptomatic cerebrovascular disease has been shown to be associated with various cardiovascular risk factors, and depressed neurobehavioural function. Diurnal blood pressure variations appear to be related to end-organ damage. The presence of occult end-organ damage and co-existing diseases common in elderly hypertensives has important clinical implications in the management of this disorder.

Computed tomography of the temporal bone in tuberculous otitis media

Nine cases of tuberculous otitis media were treated by us over the past 10 years. Six patients presenting with large tympanic membrane perforations were treated for suppurative otitis media at various ENT clinics. The remaining three patients presented without perforation. Intractable otorrhoea, aggravation of hearing loss, dizziness, and in one case facial palsy, resulted in eventual referral to us. Histological examination revealed a tuberculous granulation, confirming the diagnosis in most cases. CT in four cases with profound sensorineural hearing loss showed bone destruction of the otic capsule around the oval window and the promontory. Changes noted included a notch in one case, disappearance of the bony contour around the hook in two cases, and a distinct fistula in the final case. A cochlear fistula seemed to be characteristic of advanced tuberculous otitis media.

High extracellular GABA levels in hippocampus--as a mechanism of neuronal protection in cerebral ischemia in adrenalectomized gerbils

Adrenalectomy protects the brain from delayed neuronal damage that occurs following transient forebrain ischemia in gerbils. Gamma-amino butyric acid (GABA) and GABA-mimetic drugs also have a neuro-protective effect. In this study we estimated the extracellular glutamate and GABA levels in the hippocampus during transient forebrain ischemia in adrenelectomized gerbils (n = 8) compared to controls (n = 6). Duration of ischemia was 10 min, and glutamate and GABA levels were measured with in vivo microdialysis. Microdialysis was started 2 h after the placement of a probe (to stabilise baseline) and samples were collected at 10-min intervals. The pattern of glutamate release did not show any difference between adrenelectomized animals and controls. Adrenelectomized animals showed marked increase in GABA levels during ischemia and upto 30 min after ischemia (P = 0.0287, 2-way ANOVA for repeated measurements). The enhanced GABA release may be one of the possible mechanisms of neuronal protection against ischemia in adrenelectomized gerbils.

Decreased glutamate release during hypothyroidism may contribute to protection in cerebral ischemia

Hypothyroidism protects the brain from the effects of transient forebrain ischemia in gerbils. The mechanism for this protection is not fully understood. In this study we looked at the release of glutamate during ischemia in gerbils exposed to surgical hypothyroidism (n = 7), chemical hypothyroidism (n = 8), and surgical hypothyroidism thyroxine-treated (n = 3) and compared them to control euthyroid animals (n = 8). The duration of ischemia was 10 min. Glutamate release was measured with in vivo microdialysis. Microdialysis analysis began 2 h after the placement of the probes (to stabilize the baseline) and collections were obtained in 10-min samples. During ischemia, there was an increase in the release of glutamate that returned to the baseline within 20 min following the insult. In animals made hypothyroid surgically and chemically, the extent of glutamate release was significantly lower than that in the controls. The release of glutamate in the surgically hypothyroid thyroxine-treated animals was similar to that in controls. The attenuated glutamate release could be a mechanism of protection during ischemia in hypothyroid gerbils.

Structure and expression of a novel rat RegIII gene

We have isolated a rat cDNA and a novel gene, Reg (regeneration-promoting gene). The cDNA encodes a 174-amino-acid (aa) RegIII protein with a 25-aa signal peptide. The RegIII gene spans 2.7 kb and consists of six exons and five introns. RegIII was expressed in regenerating pancreatic islets, but not in normal islets.

A common ancestry for multiple catalytic antibodies generated against a single transition-state analog

Immunization with a single haptenic transition-state analog generates a few catalytic antibodies among the dozens of antibodies capable of binding the hapten. The diversity of the immune response has raised some fundamental issues, such as How do catalytic and noncatalytic antibodies differ on a structural basis? To address this issue, the variable region primary sequences of 11 antibodies (including 6 catalytic and 5 noncatalytic antibodies) elicited against a single haptenic transition-state analog were deduced from cDNA sequences. Cluster analyses using phylogenetic trees constructed by the neighbor-joining method have revealed that the amino acid sequences of noncatalytic antibodies bear no relationship to one another, while the catalytic antibodies share significant structural identity. Furthermore, no catalytic antibodies possessing amino acid sequences with high homology to those of noncatalytic antibodies were detected. Five catalytic antibodies examined showed 89-95% and 74-84% sequence homologies in the complete light- and heavy-chain variable regions, respectively. Thus, it seems likely that the catalytic antibodies elicited against a single hapten use the canonical set of variable region genes. Interestingly, one catalytic antibody showed only limited sequence similarity to the other catalytic antibodies and was found to exhibit a distinctly different substrate specificity. From the broad range of their binding constants to the hapten, it is unlikely that highly homologous catalytic antibodies are generated as a result of simple high-affinity choices. These results emphasize the utility of rationally designed transition-state analogs for the induction of antibody molecules with catalytic activity.

Polysplenia accompanied by major cardiovascular anomalies with prolonged survival

A 52-year-old female with polysplenia accompanied by major cardiovascular anomalies (a ventricular septal defect, atrial septal defect, persistent left superior vena cava, absent inferior vena cava with a hemiazygos connection and visceral heterotaxia) is reported. She underwent successful surgical treatment and showed prolonged survival.

Prevention of diabetes by thymic hormone in alloxan-treated rats

We investigated the effects of facteur thymique sérique (FTS), a thymic peptide hormone, on alloxan- and streptozotocin-induced diabetes in rats. Pretreatment with intravenous injection of FTS significantly suppressed both alloxan- and streptozotocin-induced hyperglycemia. The effects of FTS were time dependent. FTS suppressed hyperglycemia in a dose range of 1-6600 micrograms/kg. Alloxan-induced hyperglycemia was completely prevented when FTS was injected in doses of 40-50 micrograms/kg 1 min before injection of alloxan. Histological examination of islet areas showed that alloxan-induced destruction of beta-cells was inhibited by FTS. FTS had no significant effects on lymphocyte subsets and immunity-related cells or on plasma superoxide dismutase activity and total glutathione level. The blood half-life time of exogenously injected FTS was short (2-3 min), indicating acute internalization of FTS into pancreatic beta-cells. Our results suggested that FTS acutely and directly blocks some initial effect of alloxan, preventing the destruction of beta-cells.

Exocrine pancreatic ductograms in insulin-dependent diabetes mellitus

OBJECTIVES

To examine the prevalence of abnormal pancreatic ductograms in patients with insulin-dependent diabetes mellitus (IDDM) and to determine the clinical characteristics of those patients.

METHODS

Pancreatic exocrine morphology was studied by endoscopic retrograde pancreatography (ERP) in 43 patients with IDDM, 12 patients with islet cell antibody (ICA)-positive non-insulin-dependent diabetes mellitus (NIDDM), and 22 patients with ICA-negative NIDDM.

RESULTS

ERP revealed a significantly higher prevalence of abnormal pancreatic ducts (dilation and stenosis, tortuosity, obstruction, and intraductal calculi) in the patients with IDDM (17/43, 40%) than in the patients with ICA-negative NIDDM (2/22, 9%, p = 0.018). IDDM patients who slowly progressed to insulin dependency more than 13 months after the onset of diabetes had a higher frequency of abnormal pancreatic ducts (13/22, 59%) than those who needed insulin therapy within 12 months after the onset (4/21, 19%, p = 0.016). There was no difference in duration of diabetes between the two groups. ICA-positive NIDDM patients also had a higher frequency of abnormal pancreatic ducts (7/12, 58%) than ICA-negative NIDDM patients (2/22, 9%, p = 0.0074).

CONCLUSIONS

These results indicate that a high proportion of IDDM patients who have prolonged histories of non-insulin dependency with ICA suffer pancreatic exocrine impairment. A similarity between IDDM with a slowly progressive clinical course and fibrocalculous pancreatic diabetes seen in tropical countries also was suggested.

Pancreatic beta-cell replication and amelioration of surgical diabetes by Reg protein

We previously isolated from a rat regenerating islet cDNA library a gene named Reg, which is expressed in regenerating islets but is not expressed in normal islets. Here we examined the effect of rat Reg protein on pancreatic beta-cell replication using both 90% depancreatized rats and isolated islets. The depancreatized rats that received i.p. administration of recombinant rat Reg protein (1 mg/kg per day) for 2 months showed amelioration of the surgical diabetes, as evidenced by a significant decrease in blood glucose with an increased beta-cell mass in the residual pancreas. In isolated rat islets, Reg protein (18-180 nM: 0.3-3 micrograms/ml) significantly increased [3H]thymidine incorporation into the nuclei of beta cells. These results indicate that Reg protein is a growth factor for pancreatic beta cells and also suggest that the administration of Reg protein could be used as another therapeutic approach for diabetes mellitus.

[A case of Wernicke's encephalopathy which accompanied a passing blindness]

The case of a chronic alcoholic patient with Wernicke's encephalopathy accompanied by passing blindness is reported and the alcoholic amblyopia is discussed in this study. The patient was a 39 year-old male who had been a heavy drinker for 13 years, and was habitually inebriated for the last one year. Disturbance of consciousness ataxia of gait, nystagmus and blindness were manifested on admission. Decreased level of serum vitamin B1 was also recognized at admission. The symptoms diminished from about a month after admission except for horizontal nystagmus. Since the patient had racket-like scotoma in his central visual field, his blindness was thought to be alcoholic amblyopia. Although alcohol dependence is associated with many physical disabilities, there are few reports about Wernicke's encephalopathy with alcoholic amblyopia. This case demonstrates the importance of careful physical examination for understanding alcohol-related disabilities and alcohol dependence.

Liver function tests of recipients with hepatitis C virus infection after bone marrow transplantation

We used the polymerase chain reaction (PCR) to determine the presence of hepatitis C virus (HCV)-RNA in serum samples obtained from 19 patients with leukaemia or severe aplastic anaemia and investigated the correlation between HCV status and the results of liver function tests after bone marrow transplantation. PCR analysis of serum samples obtained before transplant showed that 10 of 18 patients were HCV-RNA-positive; 5 of these patients had developed acute post-transfusion hepatitis 1-11 months before transplant. An additional patient was HCV-RNA-positive on post-transplant day 62. Eight HCV-RNA-positive patients had pre-transplant GPT levels above the upper limit of normal. In these patients the GPT decreased significantly from a median of 104 IU/l (54-822 IU/l) pre-transplant to 23 IU/l (15-56 IU/l) on post-transplant days 8-12. In 9 of 11 HCV-RNA-positive patients, the GPT increased transiently from days 40 to 50 and again increased after day 100. Two of these patients died from hepatic failure; the GPT levels normalised in 3 patients after day 300 but continued to fluctuate in 4 patients. In the remaining 2 HCV-RNA-positive patients, the GPT remained close to the normal range throughout the follow-up period. Three HCV-RNA-positive patients became HCV-RNA-negative after 1-3 years. In these patients, the GPT remained normal for > 3 years after day 300.(ABSTRACT TRUNCATED AT 250 WORDS)

Transport and accumulation of 1,5-anhydro-D-glucitol in the human erythroleukemia cell line K-562

The transport and intracellular accumulation of 1,5-anhydro-D-glucitol (AG) was studied in the human erythroleukemia cell line K-562 by gas chromatography-mass spectrometry in conjunction with liquid scintillation spectrometry. K-562 cells contained 106 +/- 6 nM/10(6) cells of free AG, primarily in the cytosol. Addition of physiologic amounts of AG to the extracellular medium resulted in rapid intracellular incorporation of AG, with a half-saturation time of 5 s. Intracellular accumulation was linear for 2 h and subsequently reached saturation. AG uptake was temperature and concentration dependent with an apparent Km of 127 mM. AG uptake and accumulation was not inhibited by fructose, fucose, galactose, mannose, glucose, or 3-O-methyl-D-glucose and was less affected by cytochalasin B or phloretin than that of 2-deoxyglucose. Phloridzin did not affect AG uptake but did inhibit 2-deoxyglucose uptake. Efflux of AG from K-562 cells depended on external AG concentration alone and was not affected by extracellular glucose concentration. Intracellular AG concentration decreased rapidly and reached zero within 10 min following removal of AG from the external medium. We therefore propose that both transport and countertransport of AG in K-562 cells are mediated by a specific carrier system.

Isolation, structural determination and expression of a novel reg gene, human regI beta

We have isolated a novel human gene and cDNA encoding a member of the regI proteins, regI beta. The gene encodes a 166-amino acid protein which has 22 amino acid substitutions in comparison with the previously isolated human reg protein, regI alpha. RegI beta was expressed only in pancreas, whereas regI alpha was expressed in kidney and stomach as well as in pancreas.

[Two cases of Campylobacter fetus subsp. fetus sepsis]

We encountered two relatively rare cases of sepsis due to Campylobacter fetus subsp. fetus (C. fetus). Case 1. A 54-year-old female with abdominal polysurgery developed a slight fever and vomiting in August 1984. Despite the administration of some digestive drugs by her family doctor, these symptoms continued. In mid-October, she was hospitalized with high fever with chill and rigor on the skin. On the third hospital day, C. fetus was detected in the blood culture. After combination chemotherapy of intravenous drip infusion of latamoxef (LMOX) (2 g/day) and oral administration of erythromycin (EM) (800 mg/day), her symptoms improved. Case 2. A 57-year-old male with diabetic retinopathy and nephropathy was hospitalized because of slight fever, general edema and pleural effusion. On the 6th hospital day, C. fetus was detected in the blood culture and he was diagnosed with sepsis. Under treatment with the intravenous drip of LMOX (2 g/day) and oral administration of EM (1200 mg/day), his condition improved. Both cases had common underlying diseases such as hypoproteinemia with edema and problems in the lower intestinal tract; the former had polysurgery and malabsorption syndrome, the latter had diffuse ulceration of the colon. Such underlying conditions may have permitted the invasion of C. fetus into the blood.

A case of appendiceal cancer metastatic to the stomach with pseudomyxoma peritonei

Appendiceal cancer associated with pseudomyxoma peritonei is a low grade malignancy and its extraperitoneal metastasis is extremely rare. We report a case of gastric metastasis of this tumor in a 76-year-old man. Two metastatic gastric tumors, which appeared after a 1-year interval, were successfully resected endoscopically. The patient was well for more than 3 years after the onset of the disease. To our knowledge, gastric metastasis from appendiceal cancer with pseudomyxoma peritonei has not been previously reported.

Noninvasive evaluation of the influence of aortic wave reflection on left ventricular ejection during auxotonic contraction

To develop a noninvasive method for evaluating the influence of aortic wave reflection on left ventricular ejection, the carotid pulse wave and the pulsed Doppler wave in the left ventricular outflow tract were evaluated in 35 patients. Agreement between the pulsed Doppler waveform and the aortic flow velocity contour (obtained invasively) was verified by Fourier analysis. The carotid augmentation index was used to determine the magnitude of the aortic pressure wave reflection. A Doppler index named "DR1/3" was defined as the ratio of deceleration at the first one-third in the deceleration phase to the peak flow velocity of the pulsed Doppler. This index was validated by close correlation with the carotid augmentation index (n = 48, r = 0.70, P < 0.01). Both nitrates and nifedipine induced a significant decrease in DR1/3 (indicating an increase in left ventricular ejection flow) in relation to a reduction of the reflected pressure wave. The new noninvasive index, DR1/3, is useful in evaluating the influence of aortic wave reflection as part of the left ventricular afterload and in assessing the benefit of treatment aimed at reducing wave reflection.

Comparative study of the effects of cefodizime and HBW 538 in potentiating the production of reactive oxygen species by human polymorphonuclear leukocytes

The immunomodulatory activity of cefodizime (CDZM), an aminothiazolylcephalosporin, was compared to that of HBW 538, a derivative of the CDZM side chain at position 3 (the mercaptothiazolyl group) in respect to the production of reactive oxygen species (ROS) by human whole blood and polymorphonuclear leukocytes (PMN) in vitro. Ten-fold diluted whole blood and PMN from healthy individuals were incubated with CDZM or HBW 538 alone at the concentrations of 1, 10, or 100 micrograms/ml, or CDZM or HBW 538 at 100 micrograms/ml in combination with tumor necrosis factor-alpha (TNF-alpha) at 100 U/ml or lipopolysaccharide (LPS) at 1 microgram/ml. The production of ROS was measured by a chemiluminescence (CL) assay in which luminol was added to a mixture and after which the PMN or whole blood were stimulated with nonopsonized zymosan or phorbol myristate acetate. The following results were obtained: (1) The CL responses of whole blood and PMN were slightly but not significantly enhanced by CDZM at 100 micrograms/ml, whereas both CL responses were significantly enhanced by exposure to HBW 538 at 10 and 100 micrograms/ml. (2) The enhanced PMN CL response which followed priming with TNF-alpha or LPS was not augmented by CDZM but was significantly augmented by HBW 538. These results indicate that the ability of the HBW 538 molecule to enhance the production of ROS by stimulated PMN and to act agonistically with TNF-alpha or LPS is abrogated when HBW 538 is part of the CDZM molecule.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of chimerism after bone marrow transplantation with single locus minisatellite DNA probes

The origin of cells in almost all allogeneic donor-recipient pairs can be determined through the use of highly polymorphic minisatellite DNA probes. Single-locus probes were cloned from hypervariable fragments in a human DNA fingerprint detected with a multi-locus probe. While each probe is highly polymorphic and locus specific, they all contain repetitive sequences. The properties of single-locus probes have improved the sensitivity of detecting mixed chimerism in comparison with multi-locus probes. The use of single-locus probes permitted detection of mixed chimerism (MC) at levels as low as 0.625%, approaching that obtained by PCR methods. In the present study, five patients who received allogeneic BMT for hematologic malignancies were analyzed. Two patients exhibited MC after BMT. One developed acute GVHD and chronic GVHD and remained in CR while the second patient who had no signs of GVHD suffered a relapse.

Structure, chromosomal localization, and expression of mouse reg genes, reg I and reg II. A novel type of reg gene, reg II, exists in the mouse genome

We previously identified a gene, reg (i.e. regenerating gene), in the screening of a regenerating islet-derived cDNA library of rat (Terazono, K., Yamamoto, H., Takasawa, S., Shiga, K., Yonemura, Y., Tochino, Y., and Okamoto, H. (1988) J. Biol. Chem. 263, 2111-2114), and isolated a human reg cDNA and gene (Watanabe, T., Yonekura, H., Terazono, K., Yamamoto, H., and Okamoto, H. (1990) J. Biol. Chem. 265, 7432-7439); the rat and human cDNAs encode 165- and 166-amino acid proteins, respectively. Until now, it was thought that there is a single locus for Reg protein in the mammalian genome. In this study, we isolated two distinct cDNAs and genes, one of which was a mouse homologue to rat and human reg gene, the other a novel type of reg gene. We designated them reg I and reg II, respectively. The two proteins encoded by these genes share 76% amino acid sequence identity with each other. Both genes span about 3 kilobase pairs, and the genomic organization of six exons and five introns is conserved between them. Chromosomal mapping studies indicate that the reg I gene is localized on mouse chromosome 12, whereas the reg II gene is localized on chromosome 3. By Northern blot analysis, both reg I and reg II mRNAs are detected in the normal pancreas and hyperplastic islets of aurothioglucose-treated mice, but not in the normal islets. It is remarkable that in the gallbladder reg I is expressed, but reg II is not.

Prodrug activation via catalytic antibodies

Prodrug activation via antibodies was examined by using the antibiotic chloramphenicol as a model drug. Based on the conformational change between substrate and product, this antibody-catalyzed reaction was designed to prevent product inhibition, thus enhancing turnover. Antibodies elicited against a phosphonate transition-state analogue were found to catalyze hydrolysis of a nonbioactive chloramphenicol monoester as a prodrug at a significantly higher rate above the uncatalyzed background reaction to regenerate chloramphenicol as a parent molecule. The antibody-catalyzed prodrug activation was tested by the paper-disc diffusion method using Bacillus subtilis as an indicator strain. The antibody 6D9 catalyzes the reaction with multiple turnover to generate enough chloramphenicol to inhibit bacterial growth, as indicated by a clear inhibitory zone after incubation with monoester. Using the same method, no inhibition was detected by incubation of either the monoester or the antibody alone. This result reveals that only the antibody hydrolytically activates the monoester, which can be expected to be a suitable prodrug, as it is resistant to the action of bacterial hydrolytic enzymes. The approach in this study demonstrates the use of catalytic antibody technology in medicine and may be applicable to drugs with undesirable effects, particularly in the field of cancer therapy.

Becker muscular dystrophy with early manifestation of left heart failure

We encountered a case of dystrophin-verified Becker muscular dystrophy which exhibited left heart failure as an initial symptom but no subjective muscle weakness. Severe cardiac involvement has been thought to rarely occur in the early stage of this disease, however accurate diagnosis was limited until the dystrophin diagnosis became available. This case suggests that some cases of dilated cardiomyopathy might be Becker muscular dystrophy, and that dystrophin tests should be added to the conventional investigation of patients with dilated cardiomyopathy.

[Acute cardiac tamponade in nonpenetrating injury of proximal aorta: report of a case]

A 21-year-old male admitted to the emergency room with multiple traumatic injuries and shock. Although a chest X-ray showed normal in size of cardiac shadow, echocardiography confirmed cardiac tamponade. A median sternotomy was performed and the pericardial space was evacuated of 600 ml of blood and blood clots. Minor bleeding was identified in the proximal aorta, and complete hemostasis was achieved with manual compression and fibrin glue sealing. One month follow-up showed no pseudoaneurysm formation.