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Biomedical subjects

S Monma

Publications and source records attributed to S Monma.

17 recordsLinked to original sources
PubMed1995

Fractures of the floor of the anterior cranial fossa.

We treated 28 patients with anterior cranial fossa floor fractures. Computed tomography (CT) scans adjusted to bone density disclosed three fracture types: (1) penetrating fractures through the orbita or ethmoid sinus; (2) simple or multiple linear fractures; and (3) extensive comminuted anterior cranial fossa floor fractures. Thirteen patients underwent emergent surgery for treatment of open depressed fractures (most common in type 3 fractures), for foreign bodies (in type 1 fractures), and for optic canal decompression. Large dural lacerations were always present in patients with type 3 fractures, and repairs were made with dural substitutes. Only one patient developed postoperative cerebrospinal fluid leakage. Nine (32%) of the patients in our series had visual involvement, but visual acuity recovered or improved in six patients. Our study shows that initial neuroradiologic evaluation with CT scans is important in patients with frontobasal fractures, and that secure dural repair during primary operation helps prevent cerebrospinal fluid leakage.

Adolescent↗
PubMed1995

Synthesis and structure-activity relationships of gelatinase inhibitors derived from matlystatins.

To investigate a series of new inhibitors of gelatinases based on matlystatin B (1b), extensive structure-activity relationship studies were performed. The new derivatives were evaluated in vitro for the ability to inhibit gelatinases. The inhibitory activities against thermolysin were also assayed to test the compounds' selectivity. Among the compounds modified at the P'3 moiety, the N-methylamide derivative 5 g was virtually twice as effective on gelatinase B as the parent compound 1b (5g, IC50 = 0.27 microM vs. 1b, IC50 = 0.57 microM). Other derivatives, including 1) esters 7a and 7b having the ester portions P'2 and P'3, 2) the cyclic amino acids, L-proline or L-pipecolinic acid (13a and 13b) bearing P'2, and 3) compounds 29a and 29b representing an attachment of the pentyl side chain at C3' (P'1 side chain) instead of C2', all showed decreased potencies. The key discovery was the observation that the introduction of a nonyl group at the P'1 position yielded a compound (31f, IC50 = 0.0012 microM) with high inhibitory activity against gelatinases and high selectivity over thermolysin. This result suggested that the S'1 subsites of the gelatinases have a locally deep hydrophobic structure, since on the basis of the optimum inhibitory activity in the alkyl series, the nonyl group seems to fit best into this hydrophobic pocket. Thus 31f exhibited a 475-fold more potent inhibitory activity than 1b towards gelatinase B.

Acetylcysteine↗
PubMed1994

Alterations in plasma concentrations of natriuretic peptides and antidiuretic hormone after subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: Hyponatremia is a common complication after subarachnoid hemorrhage. In this study we investigated the relations among hyponatremia, plasma natriuretic peptides, and antidiuretic hormone concentrations after subarachnoid hemorrhage. METHODS: Blood samples for radioimmunoassay measurement of plasma brain natriuretic peptide-like immunoreactivity, atrial natriuretic peptide-like immunoreactivity, and antidiuretic hormone were obtained every 2 to 4 days until day 14 after subarachnoid hemorrhage. RESULTS: Eleven of 20 patients with verified subarachnoid hemorrhage demonstrated mild hyponatremia (126 mEq/L < serum sodium < 135 mEq/L) during their clinical course. Atrial natriuretic peptide and antidiuretic hormone concentrations were significantly elevated on days 0 to 2 after onset of subarachnoid hemorrhage. Atrial natriuretic peptide concentrations remained high in patients who developed mild hyponatremia on days 6 to 14 after onset of subarachnoid hemorrhage. In contrast, antidiuretic hormone concentrations became significantly lower during the second week in these patients. CONCLUSIONS: Mild hyponatremia after subarachnoid hemorrhage may be attributable not to the syndrome of inappropriate secretion of antidiuretic hormone but to cerebral salt-wasting syndrome. Atrial natriuretic peptide may be a causal natriuretic factor in cerebral salt-wasting syndrome.

Adult↗
PubMed1993

Low incidence of seizures in patients with chronic subdural haematoma.

A total of 129 patients treated for chronic subdural haematoma were studied retrospectively to evaluate the incidence of seizures. None of 73 patients who were given prophylactic antiepileptic drug treatment developed seizures. Only two of 56 patients not given prophylaxis, developed early postoperative seizures. In these two, surgical technique was thought to be responsible. One patient developed complex partial seizures preoperatively. The incidence of seizures was therefore low, and similar to that previously reported for minor head injury. This study suggests that routine use of antiepileptic prophylaxis is not justified in patients with chronic subdural haematoma caused by minor head injuries, or other causes when there are no additional lesions present on CT scans.

Adolescent↗
PubMed1991

Symptomatic cerebral vasospasm of unusually late onset after aneurysm rupture.

An unusually late occurrence of symptomatic cerebral vasospasm is reported. The case involves a 50-year-old male who was uneventfully operated on for a ruptured anterior communicating artery aneurysm, with no symptom of cerebral vasospasm, 17 days after sustaining the subarachnoid haemorrhage. Two days after surgery, a right hemiparesis developed and angiography disclosed severe cerebral vasospasm. This case history and the aetiological factors of symptomatic vasospasm are discussed.

Cerebral Angiography↗
PubMed1990

Cavernous angioma with encapsulated intracerebral hematoma: report of two cases.

Two cases of a cavernous angioma with an encapsulated intracerebral hematoma are presented. In both instances, computed tomography scan showed a ringlike appearance with a nodular lesion. Cerebral angiograms of the two cases, however, were normal. The preoperative diagnosis for both cases was a brain neoplasm. The diagnostic problems that this type of vascular malformation presents and its role in the development of the encapsulated hematoma are discussed.

Adult↗
PubMed1990

Saccular aneurysms of the distal anterior cerebral artery.

We report a series of 42 consecutive patients with aneurysms of the distal anterior cerebral artery (ACA). Of these, 36 patients had one aneurysm, 5 had two aneurysms, and one had three aneurysms. Thirty patients had a ruptured distal ACA aneurysm; among these patients, the size of the aneurysm was less than 5 mm in diameter in 20, 6 to 10 mm in 7, and larger than 11 mm in 3. Eighteen patients (42.9%) had multiple aneurysms, and distal ACA aneurysms were responsible for a subarachnoid hemorrhage in 10. Thirty-four patients underwent direct surgery, and 30 of these had excellent outcomes 3 months after surgery. The treatment of patients with distal ACA aneurysms is often technically difficult, because of their broad neck configuration and the coexistence of other aneurysms. Nevertheless, the present study emphasizes that distal ACA aneurysms tend to bleed, irrespective of their size, and that excellent outcomes are obtainable by direct surgery.

Adult↗
PubMed1989

Unruptured aneurysms in patients with transient ischemic attack or reversible ischemic neurological deficit. Report of eight cases.

Thirty-five patients with unruptured aneurysms were treated between 1981 and 1987. Eight of them had either transient ischemic attacks or reversible ischemic neurological deficits as their presenting symptoms. Six of the eight patients underwent direct aneurysm surgery. All eight patients are well, and have had no recurrent attack during the follow-up period ranging from 2 to 7 years. The feasibility of surgical treatment for such aneurysms associated with reversible ischemic symptoms is discussed.

Aged↗
PubMed1988

A review of 102 consecutive patients with intracranial aneurysms in a community hospital in Japan.

One hundred and two consecutive non selected patients with intracranial aneurysms were reviewed. The incidence of ruptured aneurysm was 17.5 per population of 100,000 per year. The patients were divided into two groups, according to a change of policy that reversed the timing of operations from delayed to early surgery. The overall mortality and occurrence rate of neurological deficits due to vasospasm in patients in Hunt and Kosnik grades I through III were found to be lower during the period with a policy of early surgery. Elderly patients over 70 years old constituted 19% of the cases and those in poor condition (grade IV and V) 31%. These figures in this study are high, which may reflect the fact that these are common problems inherent in the treatment of ruptured aneurysms without patient selection at most community hospitals in the forefront of primary medical care.

Adult↗
PubMed1987

Chronic subdural haematoma preceded by persistent traumatic subdural fluid collection.

The role of traumatic subdural fluid collections in the development of chronic subdural haematomas was studied in 43 of 715 patients who underwent a CT scan because of a recent head injury. Twenty of the 43 patients subsequently developed a chronic subdural haematoma, and this occurred especially in the aged. Nearly 50% of patients with asymptomatic or minimally symptomatic subdural fluid collection may develop a chronic subdural haematoma.

Adult↗
PubMed1987

[A clinical study on head injuries in the aged].

We review 79 patients over 65 years old among 715 patients who underwent CT scans in the early period after head injuries, to study the characteristics of head injury in the aged. Among 79 aged patients, 24 developed posttraumatic subdural fluid collections, and in 13 of them chronic subdural hematomas developed subsequently. There were only three acute epidural hematomas. However, a high incidence of intracerebral lesions was noted, regardless of the presence of skull fracture. The pedestrian accident was the most frequent cause of head injury in the 36 aged patients admitted and the mortality rate of traffic accident in the aged was also highest. The relationship between Glasgow Coma Scale Score (GCS) on admission and the outcome was not parallel in the aged, because high GCS not rarely resulted in poor condition or death. Head injury is apt to occur and becomes severe in the aged pedestrian because of advancing carelessness and dull movements with age. The vulnerability of the brain to the injury and changes of intracranial environment in the aged tend to cause intracranial lesions much more than in the younger patients. Already-existing diseases and/or posttraumatic general complications also make clinical courses worse in the aged. It seems important for the improvement of the treatment that the characteristics described above are always taken into consideration throughout the period of the treatment in the aged, in order to eliminate worsening factors adequately. In addition, the social measures to cope with the suffering of the aged pedestrians from traffic accident should be considered and established in an aging society.

Accidents, Traffic↗
PubMed1986

Role of traumatic subdural fluid collection in developing process of chronic subdural hematoma.

We investigated the role of traumatic subdural fluid collection in the genesis of chronic subdural hematoma (CSDH) in 43 consecutive patients with traumatic subdural fluid collection. Traumatic subdural fluid collection was found in 43 (6%) of 715 patients who underwent CT scans because of head injury. Twenty-four of the 43 patients were more than 65 years of age and this problem occurred in 30% of the 79 head-injured patients over 65 years of age. In 20 (Group 1) of the 43 patients CSDH subsequently developed. During the same period, 30 other patients were treated for CSDH. Twenty-four (Group 2) of these 30 patients had a history of head injury more than two weeks prior to the developing signs and symptoms and had hyper- or iso-dense hematomas on their first CT scan. It may have been that they too first had a traumatic subdural collection. Forty to sixty percent of the patients with asymptomatic traumatic subdural fluid collection may develop CSDH, and this may occur especially in the older patients. Careful observations after the head injury are particularly important in the aged because of the frequent occurrence of traumatic subdural fluid collection and the subsequent development of CSDH.

Adult↗
PubMed1979

[Pediatric metrizamide CT cisternography and CT ventriculography (author's transl)].

We have studied the diagnostic value of computed tomography with metrizamide CSF enhancement in 37 infants. According to the method of injection, we called CT cisternography, CT ventriculography and CT cystography. These methods were useful for the morphologic and dynamic evaluation of the CSF pathways. We used them especially for the evaluation of hydrocephalus, skull base tumor, infantile subdural hematoma and its allied diseases, or congenital cystic lesion such as Dandy-Walker syndrome. The side effects in children are much less than those in adults.

Adolescent↗