New reconstructive procedure for brachial plexus injury

The double free-muscle transfer technique has restored prehension in patients following complete avulsion of the brachial plexus. This achievement was almost inconceivable as recently as several years ago and has now given new hope for these patients to be able to use their otherwise useless limbs.

Nerve regeneration and origin of Schwann cells in peripheral nerve allografts in immunologically pretreated rats

For peripheral nerve allografts, the conditions for successful nerve regeneration and the possibility of transplanting Schwann cells were examined using a model of pretreated rats. Incomplete immunosuppression was achieved in recipient rats with donor red blood cell infusions given before allogeneic nerve grafting (RBC group). The origin of Schwann cells in the grafts was assessed by immunohistochemical staining from 1 week to 12 weeks after transplantation. In the RBC group, the replacement of donor Schwann cells by recipient cells was detected at 3-8 weeks, with the graft being filled with many of these cells at all times, and successful nerve regeneration was seen after 12 weeks on morphometric and electrophysiologic evaluations. In peripheral nerve allografts, pretreatment with donor-specific blood transfusion did not induce significant immunosuppression compared with allotransplantations of some tissues and organs. Clinically, if the state of immunosuppression can be controlled by RBC transfusion, it is possible that donor tissues may be replaced by recipient tissues and that nerves will regenerate successfully.

Brain ischemia and gastric mucosal damage in spontaneously hypertensive rats: the role of arterial vagal adrenoceptors

Brain ischemia is often accompanied by acute gastric lesions. To clarify the underlying mechanism, the influence of acute ischemic insult to the brain on gastric hemodynamics and mucosal integrity was examined in spontaneously hypertensive rats. One hour after brain ischemia, gastric mucosal blood flow decreased to 71% of the preischemic levels in the control rats but was preserved significantly better, at 94 and 108%, in the prazosin-treated and guanethidine-treated rats, respectively. Vagotomy almost abolished the decrease in gastric mucosal blood flow during cerebral ischemia. Intragastric 0.6 N hydrochloric acid administered just after reperfusion induced more severe hemorrhagic ulcers in the control than in the prazosin-treated and vagotomized groups. These results suggest that noradrenergic neurons acting through alpha1-adrenoceptors contributes to the decrease in gastric mucosal blood flow, and the subsequent disturbed integrity of the gastric mucosa, through the vagal adrenergic pathway during brain ischemia in spontaneously hypertensive rats.

Renal glomerular fibrosis in a cat

Renal glomerular fibrosis was observed in a 1-year-old spayed female Japanese domestic cat that showed clinically advanced renal failure. In the glomeruli, increased homogeneous materials were stained strongly with aniline blue by Masson's trichrome and positive for anti-type III collagen antibody by immunohistochemical staining, causing mesangial sclerosis and capillary collapse. By electron microscopy, randomly arranged fibrils were observed in the expanded subendothelial and mesangial areas, and the fibrils showed periodicity characteristic of collagen fibers in longitudinal sections. These findings of glomerular lesions closely resemble those of human "collagenofibrotic glomerulonephropathy," which has recently been described as a new type of glomerulonephropathy.

Regulation of oxygen diffusion in hypoxic isolated cardiac myocytes

In the normal beating heart, oxygen pressure (PO2) gradients between capillary blood and intracellular space are so large that cytosolic PO2 may decline to around PO2 at half saturation of myoglobin (2-5 Torr). Hence, a decrease in capillary blood PO2 of a few Torr would easily deplete oxygen in mitochondria if PO2 gradients are unchanged. The aim of the present study was to demonstrate, in a single isolated cardiac myocyte of the rat, a mechanism that reduces PO2 gradients in hypoxia so that oxygenation of the intracellular space would be sustained. Using a newly developed microspectrophotometric device, we were able to follow changes in cytosolic PO2 of an individual ventricular myocyte in an hypoxic medium. For extracellular PO2 of 4.4 Torr, we found an elevation (2.1 Torr) of the cytosolic PO2 when oxygen consumption of the cell was abolished by 2 mM NaCN, thus demonstrating PO2 gradients from extracellular medium to cytosolic space in a single individual cardiomyocyte. The magnitude of these PO2 gradients was reduced as extracellular PO2 was further lowered, and they were no longer detectable for extracellular PO2 of 0.6 Torr. To further elucidate physiological effects of the PO2-dependent changes in PO2 gradients demonstrated above, we conducted a simulation of ischemia in a single cardiac myocyte. The stop-flow procedure (simulated ischemia) quickly decreased cytosolic PO2 from 7.3 to 1.8 Torr in 5 min, while the rate of fall of PO2 considerably decreased when the cytosolic PO2 decreased to < 2 Torr. Consequently, even 30 min after the onset of the stop flow, cytosolic PO2 was significantly higher than that of the anoxic perfusion. These results together suggest that in severe hypoxia oxygenation of the intracellular space might be partially maintained by relative elevation of cytosolic PO2, resulting from progressive decrease in PO2 gradients from extracellular space to cytosol.

Plant regeneration of eucalypts from rotating nodule cultures

Nodule cultures were induced from shoot tips of aseptically grownEucalyptus botryoides in a vertically rotated incubator. N-(2-chloro-4-pyridyl)-N'-phenylurea (4PU) was a very effective cytokinin for induction of nodules in liquid B5 basal medium supplemented with naphthalene acetic acid and 3% sucrose.The effective concentration of 4PU ranged from 0.2 to 0.5mg/l. The nodule had a very smooth surface and was composed of small meristematic cells outside and large vacuolated cells inside. Shoots were regenerated from these cultures on media supplemented with 6-benzyladenine at 0.2mg/l in place of 4PU. These regenerated shoots were successfully rooted and cultivated in the field. Nodule cultures were maintained for 3-4 years with monthly subcultures without losing proliferation and regeneration abilities. Nodules were also successfully induced from other eucalypts, namelyE. camaldulensis, E. deglupta andE.grandis with slightly modified media. Furthermore, nodule cultures were also induced from shoot tips of field-grown plants inE.camaldulensis. This system is beneficial for both mass propagation of selected elite clones and creation of genetically engineered plants.

[Statistical analysis of recovery from sudden deafness among treatment groups]

This study examined 131 patients with idiopathic sudden deafness in whom the averaged of five frequency hearing levels was greater than 60dB. Since combined pharmacotherapy has been used in the treatment of idiopathic sudden deafness, it is hard to make a quantitative analysis of single-drug efficacy. We used a single-drug treatment in turn to assess the drug efficacy within 30 days after the onset. There was no significant difference among patients treated within 6 days and not less than 7 days after the onset with steroid therapy, PGE1 therapy, and defibrinogenation therapy. Similarly, there was no significant difference among patients treated within 6 days and not less than 7 days after the onset with steroid and defibrinogenation combined therapy, steroid and PGE1 combined therapy, and steroid, defibrinogenation and Lasix-Vitamin combined therapy. In case of no steroid effect, treatment with defibrinogenation, PGE1 and Lasix-Vitamin therapy could achieve hearing improvement.

Density correction of peripheral breast tissue on digital mammograms

When digital mammograms are viewed on video displays, evaluation of the skin and subcutaneous tissue is often difficult and may require special window settings. An algorithm has been developed for selective enhancement (ie, density correction) of the dark peripheral portions of the breast on mammograms. After an automated segmentation of the digital mammogram and identification of the skin line, a fitted enhancement curve is generated to selectively enhance all pixels within a certain distance from the skin to match the density of the center part of the breast. After enhancement, skin and breast parenchyma can be evaluated simultaneously without the need for different window settings. When tested on a set of 400 digitized mammograms, the density correction algorithm significantly (P < .0001) increased the maximum area of breast tissue visualized simultaneously at window width settings of 0.5-2.0 delta OD (optical density). Artifacts interfering with interpretation were observed in less than 1%. The algorithm for correcting the density of peripheral breast tissue substantially facilitates and improves the display of digital mammograms and thus will be a valuable component of an integrated workstation for computer-aided diagnosis in mammography.

Variation in serum creatine phosphokinase activity as indicated in two-phase EMC-D virus-induced myocarditis

In this study, myocardial damage in the D-variant of encephalomyocarditis (EMC-D) virus-induced myocarditis has been investigated consecutively by measuring serum creatine phosphokinase (CPK) activity. CPK activity in 8 week-old male BALB/cAJcl mice inoculated with EMC-D virus increased to a peak at 4 or 5 days postinoculation (DPI) and then gradually decreased. The CPK activity rose again after 7 DPI until it reached a second peak. In view of the kinetics of CPK activity, two-phase (early and late phase) myocardial damage in EMC virus infection were considered. In the late phase, an increase in cellular infiltration in the myocardium and a decrease in viral titer in the heart were observed. It was therefore suspected that the increase in CPK in the late phase may be caused by cellular infiltration, but not by viral replication. In our results, we suggested that a serial measurement of serum CPK activity might be a useful method for throwing more light on the myocardial damage caused by the autoimmune response. We also used a pathological (TUNEL) method to detect apoptotic cells and some apoptotic myocytes in the myocardium in late phase EMC virus-induced myocarditis.

Age-related histochemical and ultrastructural changes in renal glomerular mesangium of APA hamsters

Syrian hamsters of the APA strain (APA hamsters) develop spontaneous mesangial thickening in the renal glomeruli from an early age. They also develop focal and segmental glomerulosclerosis (FSG) at and after 6 months of age. In this study, histopathological, histochemical and electron microscopical examinations were conducted to clarify the age-related renal glomerular changes in spontaneous FSG of APA hamsters. Histopathological analysis revealed that expansion of the mesangial region and thickening of the glomerular basement membrane (GBM) in the glomeruli of APA hamsters progressed with age. These age-related changes appeared earlier in male animals. Immunohistochemical analysis suggested that type IV collagen was responsible for the expansion of the mesangial region and thickening of the GBM. In lectin histochemical analysis, positive sites for WGA with and without neuraminidase pretreatment and PNA with neuraminidase pretreatment were detected mainly in podocytes and were expanded with age. Ultrastructurally, the increase in basement membrane-like materials in the mesangial matrix, development of intracellular organella of mesangial cells and migration of a part of the mesangial cell cytoplasm into the GBM were observed at and after 6 months of age. These features suggested that mesangial cells played an important role in the age-related expansion of the mesangial region and thickening of the GBM.

Spontaneous comedones on the skin of hairless descendants of Mexican hairless dogs

In the first experiment, the skin sebum and humidity, perspiration ability of sweat glands, and histology of spontaneous comedones were examined in hairless descendants of Mexican hairless dogs. The skin of females showed lower humidity than that of males. Some animals with a large number of comedones exhibited remarkably high skin sebum scores. The comedones were distributed throughout the dorsal skin, and a cluster of lesions was found mainly in the limbs and prepuces. The sweat glands showed no perspiration in the sudorific test. Histologically, both infant and adult animals had lesions of micro- and/or "blackhead" comedones. Plugged follicles containing abundant keratic substances associated well-developed sebaceous glands. Spontaneous comedones in the skin of hairless dogs were grossly and histologically similar to the acne vulgaris observed in human beings. The skin of some adult animals showed a large number of protrusive comedones which were solid cystic structures containing organized substances. In the second experiment, three kinds of antiacne agents (sulfur and camphor, sulfur and resorcinol, and ibuprofen piconol) were applied daily to the test sites for one month. These antiacne agents caused prominent extrusion of keratin plugs from follicular sites. The results suggest that the hairless dogs are a predictive model for evaluating the efficacy of antiacne agents proposed for acne treatment.

Archaebacterial lipid models: stable liposomes from 1-alky1-2-phytanyl-sn-glycero-3-phosphocholines

1-Alky1-2-phytanyl-sn-glycero-3-phosphocholines (HPhyPC: alkyl = n-C16H33; EPhyPC: alkyl = n-C20H41), which are artificial chimeric lipids between archaebacterial and ordinary glycerolipids, are prepared. Upon sonication in aqueous media, the lipids gave rise to stable unilamellar liposomes having diameter of 200-1,000 A and gel-to-liquid crystalline phase transition temperature of -11.1 degrees C (EPhyPC) and -10.8 degrees C (HPhyPC). The vesicles were thermally stable (to about 70 degrees C) and retained efficiently 5(6)-carboxyfluorescein and sodium chloride in the aqueous interior. Physicochemical properties of their membranes were discussed in comparison with those of the membranes made of an archaebacterial model lipid, 1,2-diphytanyl-sn-glycero-3-phosphocholine.

[Two successful cases of surgical treatment for left ventricular rupture following myocardial infarction: the usefulness of percutaneous cardiopulmonary support system (PCPS)]

Two successful cases of surgical treatment for left ventricular (LV) rupture following acute myocardial infarction (AMI) are reported. The first case was a 62-year-old man with circulatory collapse caused by a blow out type LV rupture. The second case was a 68-year-old woman with a oozing type LV rupture. In both cases PCPS was applied for cardiopulmonary resuscitation. After stabilizing their hemodynamics and recovering consciousness with PCPS, surgical repair for LV rupture was performed successfully. The first case was getting well, but suddenly circulatory collapse occurred and he died for acute pulmonary arterial thromboembolism on 10 days after operation. The second case woman is doing well without complication 1 year after operation. In conclusion, PCPS may be useful for LV rupture following AMI for the recovery and maintenance of hemodynamics, and also play as a bridge for surgical repair.

Clinical use of extracorporeal lung assist for a patient in status asthmaticus

A 23-year-old man was transferred to our hospital in an unconscious state due to hypercapnea with massive subcutaneous emphysema secondary to status asthmaticus. Mechanical ventilation was ineffective for removal of carbon dioxide and oxygenation. After the initiation of extracorporeal lung assist the patient was able to effectively clear his secretions. This resulted in marked improvement in his pulmonary compliance. There were no hemorrhagic pulmonary or hematologic complications. This is the first patient in whom we have used venovenous bypass in the treatment of status asthmaticus.

The limit of low speed peripheral nerve elongation; neurological and circulatory aspects

We studied peripheral nerve elongation of rabbit sciatic nerves. External fixators developed in our department were applied to 32 rabbit femurs in vivo. The rabbits underwent osteotomy of the femur and were divided into two groups subjected to different sciatic nerve elongation speeds: group I (0.45 mm/day) and group II (1.35 mm/day). The sciatic nerves were elongated 1.5, 3.0, 4.5, 6.0 and 7.0 cm by the external fixators, and the corresponding actual percentage of elongation of the nerves were 8, 16, 24, 30 and 40%. After elongation, nerve electrophysiology, nerve blood flow and pathology were studied. Forty percent elongation decreased nerve blood flow to 69 +/- 5.1% of contralateral controls in group I and to 20 +/- 4.8% in group II. Although no decrease in motor conduction velocity (MCV) was observed at any elongation distance, compound muscle action potential (CMAP) amplitude gradually decreased with increasing elongation. In group I, after 40% elongation, specimens showed the following pathologic changes: thinning of myelin sheath, atrophy and detachment of the axon from the myelin sheath. Furthermore, in group II, 40% elongation induced disorganization of the myelin sheath and Wallerian degeneration. Consequently 40% elongation was regarded as critical at speeds of both 0.45 and 1.35 mm/day.

Impregnation of basic fibroblast growth factor on a microporous small caliber graft enhances vascularization

The incorporation of a cellular adhesive extracellular matrix and a growth factor into a designed concept for a vital, functioning artificial vascular graft may accelerate tissue regeneration, including endothelialization. Microporous polyurethane grafts (inner diameter, 1.5 mm; wall thickness, 100 microns; length, 20 mm; pore size, 100 microns), fabricated using an excimer laser ablation technique, were coated with a mixed solution of photoreactive gelatin, basic fibroblast growth factor (bFGF), and heparin, and were subsequently photocured by ultraviolet irradiation. Control grafts were treated only with photoreactive gelatin. Both bFGF/heparin impregnated grafts (n = 6) and control grafts (n = 9) were implanted in aortas of rats for 4 weeks. All the implanted grafts were patent when harvested. Endothelialization mainly proceeded from anastomotic sites for both groups. The endothelial coverage in the bFGF/heparin impregnated groups was greater than that in the control animals. At the midportion of the grafts, regenerated endothelial and subendothelial layers were seen for the bFGF/heparin groups, but only fibrin layers were seen for the controls. Thus, coimmobilization of bFGF and heparin significantly enhanced neoarterial wall regeneration through perianastomotic as well as transmural tissue ingrowth. The former was more extensive than the latter.

Image feature analysis for computer-aided diagnosis: detection of right and left hemidiaphragm edges and delineation of lung field in chest radiographs

Diaphragm edges, together with ribcage edges, in chest radiographs provide useful information on the location, shape, and size of the lung fields that are required by computer-aided diagnosis (CAD) schemes for automated detection of various abnormalities. In this continued study, we developed a computerized method for detection of the right and left hemidiaphragm edges. First, the right hemidiaphragm edges in a PA (postero-anterior) chest image were determined by edge gradient analysis. An initial vertical ROI was then placed at the middle of the left hemidiaphragm, based on a "standard rule" for determination of the starting points to search for the left hemidiaphragm edges. Seven categories were used to assess the accuracy of the placement of the initial ROI and the selection of the primary left starting point within the initial ROI. For some categories, it was necessary to select a second left starting point besides the primary one. Therefore, for these categories, two sets of "detected left hemidiaphragm edges" resulted from the two left starting points. Two parameters were used as measures to eliminate the false left hemidiaphragm edges which were due to an incorrect left starting point. Two polynomial functions were applied separately which produced smooth curves for the right and left hemidiaphragm edges. Finally, the delineation of the lung field in a chest image was obtained by connecting the right and left hemidiaphragm edge curves with the corresponding ribcage edge curves. The subjective evaluation results indicated that the accuracy for the determination of the right and left hemidiaphragm edges was approximately 97% and 90%, respectively.

Posterior lens rupture in rats

Rupture of the posterior lens capsule with extrusion of lens fibers or entire lens cortex and nucleus was found in Sprague-Dawley rats. The lesion was detected during an ophthalmoscopic examination as round shadows that interfered with the view of the fundus. By slit-lamp biomicroscopic and dissecting microscopic examinations, the shadows were related to opaque plaques located on the posterior capsule. By light microscopic examination, the posterior lens capsule was ruptured and lens fibers extruded into the vitreous. Mononuclear and multinucleated giant cells were present at the site of rupture, however, few other inflammatory responses were present. Although the incidence and pathogenesis of the lesion is unknown, the lesion should be considered along with other spontaneous ocular changes when evaluating safety assessment studies.

Apoptosis in the aged dog brain

Apoptosis similar to that seen in Alzheimer's disease patients was found in the brain of aged dogs by the TUNEL method of detecting in situ DNA fragmentation. Apoptosis was observed in both neurons and glial cells, and was morphologically characterized by round and swollen cytoplasm and aggregated nuclear chromatin, although these changes were slight. Neurons and astrocytes in the gray matter and oligodendrocytes in the white matter were affected. The number of ApopTag-positive brain cells increased slightly with age, but was not correlated to the number of senile plaques. A good correlation between the number of ApopTag-positive cells and the dementia index was clearly found. The present study indicates that brain cell apoptosis could account for dementia in aged dogs and suggested that aged dogs may be useful as a simplified animal model for Alzheimer's disease in man.

Immunohistochemical characteristics of the constituents of senile plaques and amyloid angiopathy in aged cynomolgus monkeys

In this study, we immunohistochemically examined the several constituents of senile plaques (SPs) and cerebral amyloid angiopathy (CAA) in aged cynomolgus monkeys. Apolipoprotein E (apoE) deposited in all mature plaques and CAA, and in half of the diffuse plaques. Alpha-1-antichymotripsin (alpha ACT) deposited in half of the mature plaques and in one third of the CAA. Amyloid precursor protein (APP), ubiquitin (Ub), and microtubule-associated protein-2 (MAP-2) accumulated in the swollen neurites of mature plaques. Glial fibrillary acidic protein (GFAP) was detected in the astrocytes and their processes surrounding the mature plaques. Tau was detected in neither the SPs nor CAA. Therefore, mature plaques involved extracellular A beta, apoE, and alpha ACT, and also astrocytes and swollen neurites. However, diffuse plaques involved only extracellular A beta and apoE. Since these features, except for tau, were consistent with those in humans, this animal model will be useful for studying the pathogenesis of cerebral amyloid deposition.

Nerve-regenerating effect of 15-deoxyspergualin. Peripheral nerve allotransplants in the rat

We studied the effect of two immunosuppressive agents, 15-deoxyspergualin and cyclosporine A, on various nerve allografts in inbred rats whose major histocompatibility complex was mismatched. As allografts, we used the sciatic nerve (20 mm) and the saphenous nerve (20 mm). We found that 1) fresh peripheral nerve allografts with a short course of 15-deoxyspergualin and cyclosporine A therapy induced more regenerated axons than autografts did, 2) a short course of 15-deoxyspergualin therapy provided better nerve regeneration than cyclosporine A therapy in all forms of nerve allografts and large caliber nerve allografts induced more regenerated axons.

The effect of x-ray beam alignment on the performance of antiscatter grids

While the qualitative effects of grid misalignment are known, we have quantified the effect of different degrees of grid misalignment on image contrast and patient exposure. Radiographs were made of a phantom consisting of five lead disks on top of a 15 cm block of lucite. Four 60 lines/cm grids, having grid ratios of 3:1, 4:1, 6:1, and 8:1 were used. When the tube was angled more than three degrees across the grid lines, the contrast improvement factor decreased substantially for all four grids, as much as 46% for an 8:1 grid with a 12 degrees misalignment. There was a concomitant decrease in film optical density, which if compensated for by an increase in patient exposure, would lead to a higher effective bucky factor. With the exception of the 3:1 grid, if the grid is misaligned by more than 6 degrees, higher signal-to-noise ratios can be attained by removing the grid and using the increased patient exposure to reduce noise.

Quantitative analysis of geometric-pattern features of interstitial infiltrates in digital chest radiographs: preliminary results

We are developing a computerized method for detection and characterization of interstitial diseases based on a quantitative analysis of geometric features of various infiltrate patterns in digital chest radiographs. In our approach, regions of interest (ROIs) with 128 x 128 matrix size (22.4 mm x 22.4 mm) are automatically selected, covering peripheral lung regions. Next, nodular and linear opacities, which are the basic components of interstitial infiltrates, are identified from two processed images obtained by use of a multiple-level thresholding technique and a line enhancement filter, respectively. Finally, the total area of nodular opacities and the total length of linear opacities in each ROI are determined as measures of geometric pattern features. We have applied this computer analysis to 72 ROIs with normal and abnormal patterns that were classified in advance by six chest radiologists. Preliminary results indicate that the distribution of measures of geometric-pattern features correlate well with radiologists' classification. These early results are encouraging, and further evaluation hopes to establish that this computerized method might prove useful to radiologists in their assessment of interstitial diseases.

Congenital mediastinal bronchogenic cyst with malignant transformation: an autopsy report

A rare autopsy case of mediastinal bronchogenic cyst with malignant transformation is presented. The cyst had been located in the anterior mediastinum for at least 28 years in a 52 year old male. Chest X-ray findings showing rapid enlargement of the cyst and biopsy of the spine for lumbago made a clinical diagnosis as suspicious mediastinal cystic teratoma with malignant transformation metastasizing to the spine. Postmortem examination revealed that the cyst was located in the anterior mediastinum extending to the left pulmonary hilum and had no connection with the tracheobronchial tree. The cyst wall consisted of bronchus-like tissue including ciliated epithelium, hyaline cartilage, smooth muscle and mucoserous glands. There were no teratomatous components in the wall. Malignant tumor predominantly consisting of round cells occurred in the thickened cyst wall and grew into the cyst cavity with direct invasion of the lung and metastases to the liver, adrenal glands, bone marrow of the lumbar spine and lymph nodes. An immunohistochemical study showed that the tumor cells frequently expressed cytokeratin, epithelial membrane antigen and carcino-embryonic antigen, occasionally CA19-9, vimentin and neuron-specific enolase. From these findings, the tumor was diagnosed as undifferentiated carcinoma arising in the mediastinal bronchogenic cyst.