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Biomedical subjects

H K Hsu

Publications and source records attributed to H K Hsu.

At least 73 records · Page 4Linked to original sources
PubMed1989

Adhesions as a cause of persistent spontaneous pneumothorax.

The authors present a case of a patient with a persistent spontaneous pneumothorax (after seven days of chest tube drainage) in whom a tear in an upper lobe bleb was held open by adhesions between the bleb and the chest wall. Radiographic findings which might indicate such a condition are presented, thus altering one to the need for early surgical intervention. Current theories regarding the pathophysiology of pneumothorax in the young and elderly patient are reviewed.

Humans↗
PubMed1989

Primary mediastinal seminoma.

Primary mediastinal seminoma is a rare neoplastic disease. Only 133 cases have been reported in the literature. Five patients with primary mediastinal seminoma had been treated at VGH from 1974 to 1986. All of them received exploratory thoracotomy but only two of them were resectable. Postoperative radiation therapy was given regardless of resection. One had additional chemotherapy due to nodal involvement. All five patients showed complete resolution and were alive and free of disease for an average follow-up period of 42.6 months (range, 5-82 months). So we conclude that mediastinal seminoma is a rare neoplastic disease and can be treated primarily by surgery. Irradiation can also induce complete remission and long term survival in those with unresectable tumors.

Adult↗
PubMed1989

Contained thoracic empyema presenting as an anterior chest wall abscess: empyema necessitatis revisited.

Protean manifestation of pulmonary and pleural space infections can be expected in drug addicts. Because of the need to establish strict environmental protection for staff and patients, even simple drainage procedures should be performed in the operating room. Without testing, these patients should be considered as potential carriers of the AIDS virus. If a subcutaneous abscess is found to extend into the pleural space, drainage and full lung expansion are attempted through a limited rib resection. If this is unsuccessful, a full thoracotomy should be done to meet these surgical objectives.

Adult↗
PubMed1988

Histologic and hemodynamic investigation on canine lung allografts.

Histologic and hemodynamic investigations were performed on 26 mongrel dogs that underwent left lung allotransplantation. All dogs received cyclosporin A and azathioprine as immunosuppressants and were divided into two groups. In the 10 Group I dogs, no preservation was performed and the animals were followed until death. The 16 Group II dogs were subdivided into two groups; Group II-A dogs received the transplantation after 6 hours preservation and Group II-B dogs received it after no preservation. All dogs in Group II were sacrificed within 14 days following the transplantation. Seven of the dogs in Group I survived for over 90 days. The major histologic findings of Group I were pneumonitis, fibrotic interstitial changes and pleural thickening. Atypical pneumocytes were observed in three dogs, however structural changes of the bronchioles, suggesting obliterative bronchiolitis, were obscure. In Group II, 75 per cent of the dogs demonstrated the histologic features of rejection and early rejection was seen in a few dogs. Under electron microscopy, vascular wall damage was indicated by swollen endothelial cytoplasm and disrupted basement membranes. Small lymphocytes accumulating around the vessels showed lymphoblastic figures with rich intracytoplasmic organellae. The mean pulmonary arterial pressure measured by right pulmonary artery (PA) occlusion was elevated just after the transplantation in Group II, but decreased on the 7th day. The mean PA was again elevated on the 14th day in those dogs in which diffuse mononuclear cell cuffing was demonstrated. We consider that the PA-occlusion test can be used for determining the degree of rejection.

Animals↗
PubMed1988

The surgical management of empyema thoracis in substance abuse patients: a 5-year experience.

Postpneumonic empyema (EMP) may develop in substance abuse patients, requiring prolonged hospitalization. An algorithm that provides quality care and a rational basis for timely surgical intervention would be advantageous. We report our five-year experience with EMP in substance abuse patients and present such a treatment plan. Sixty-one substance abuse patients were treated for EMP. Posteroanterior, lateral, and decubitus x-ray studies were obtained before treatment to assess fluid movement. Chest tubes were placed to drain frank pus and to obtain material for positive smears. X-ray studies and computed tomography were done 24 hours later to assess parenchymal pathology and to detect any multiple loculations. Thirty-three substance abuse patients recovered following initial tube thoracostomy and 7 after a second chest tube was introduced. Twenty-one had multiple loculations and underwent thoracotomy. Twenty of the 21 required extensive debridement or decortication, or both; 2 required lobectomy and 1 pneumonectomy. Chest tubes were removed on an average of 6 +/- 1.5 days. Average postoperative stay was 10.7 +/- 2 days. There were 2 early deaths and 1 late death and no recurrent EMP. Bacteriology findings were nonspecific and often polymicrobial. We conclude that early thoracotomy can be lifesaving in the presence of a benign clinical course.

Adolescent↗
PubMed1988

The temporal relationship in arterial and venous prostacyclin and thromboxane activity during 24 hours of intraaortic balloon counterpulsation in dogs.

We studied the effects of intraaortic balloon counterpulsation (IABCP) on prostacyclin (PGI2) and thromboxane (TXB2) levels in dogs during 24 hours of 1:1 IABCP or a sham procedure in which the balloon was positioned but left deflated. The arterial PGI2 levels in the IABCP group increased from control values of 95 +/- 20 pg/ml to 268 +/- 95 pg/ml at 1 hour, 429 +/- 95 pg/ml at 4 hours, and 1,884 +/- 532 pg/ml at 24 hours. The arterial PGI2 levels were consistently higher in the IABCP group. Although the TXB2 measurements revealed no significant differences between groups, the IABCP group consistently had a higher level than the sham group. The platelet count in the control group decreased to 45% of baseline levels versus 55% for the IABCP group. We conclude that prolonged IABCP results in either net production of PGI2 or decreased degradation. The correlation between TXB2 and platelet counts is unclear and remains to be defined.

Animals↗
PubMed1988

Neuroblastoma: a rare primary intrathoracic neurogenic tumor in adults.

Mediastinal neuroblastomas, which are common malignancies of childhood, are extremely rare in adults. This article presents a case of mediastinal neuroblastoma in a 57-year-old man. To the authors' knowledge, this is only the second recorded case of such a tumor in an adult. The patient's clinical course is described and is compared with other cases (in children, except for one instance) cited in the literature. The authors discuss the early diagnosis and surgical management of these uncommon lesions, which tend to be quite extensive and rapidly fatal, and which should be suspected in adults who present with a mediastinal mass.

Journal Article↗
PubMed1988

The outcome of thymectomy in nonthymomatous myasthenia gravis.

From October 1979 to December 1984, 77 patients with nonthymomatous myasthenia gravis underwent thymectomy and 74 patients were available for careful follow-up study in this review. Among these 74 patients, 18 were male and 56, female. Their ages ranged from 13 to 68 years with an average age of 30.2 years. Men tend to be affected at a later age than women (an average age of 38.0 versus 26.1 years). Duration of the disease was from one to 30 years, with an average of 4.2 years. A sternal-splitting incision was performed for all patients. Thymectomy was made by removal of all anterior mediastinal fat between the pleuropericardial reflection and phrenic nerve bilaterally. Seventy of the 74 patients benefited from thymectomy. Of these, 34 patients had remission and 36 patients had substantial improvement; three patients did not improve after thymectomy but did not increase in severity of symptoms or medication requirement. There was no postoperative death. Myasthenic crisis developed in four patients and five patients had pulmonary complications. These nine patients were among the 21 patients who did not receive either plasmapheresis preoperatively or a high dose of steroids perioperatively. Early thymectomy is recommended for patients with nonthymomatous myasthenia gravis. We also recommend that patients undergoing thymectomy should be treated either with plasmapheresis preoperatively or with high doses of steroid perioperatively.

Adult↗
PubMed1987

Left-to-right shunts in control of bleeding following surgery for aneurysms of the ascending aorta.

Surgical repair of complex thoracic aneurysms requiring aortic valve replacement and coronary revascularization is occasionally complicated by significant bleeding despite the experience of the surgeon. While bleeding from the mediastinal tissues and the anterior suture line is usually easily controlled, posterior bleeding may require dismantling the repair and a second bypass run. The synergism of a second bypass run and continued bleeding may result in increased mortality and/or morbidity. We recently encountered bleeding in a patient who developed ventricular dysfunction after bypass and opted to interpose a Gore-tex graft between the aneurysm wall and the right atrium with immediate hemostasis and a benign course. Subsequently we used four different shunts successfully in 9 of 33 patients. The average bleeding rate 30 minutes after protamine was 221 +/- 60 ml/minute with a range of 190 to 350 ml/minute. The initial two hour chest tube drainage averaged 880 +/- 285 ml with a range of 490 to 1300 ml. There were no re-explorations for bleeding. The shunt in the first patient has remained open without cardiac decompensation. The last patient developed heart failure and required elective repair of a leak at the descending end of an arch replacement. Our experience suggests that these shunts can be effective, particularly if posterior suture line bleeding is encountered.

Aged↗
PubMed1986

Effects of long-term testosterone replacement on copulatory activity in old male rats.

Various parameters of copulatory behavior were examined in intact and castrated testosterone-(T-)treated male rats of various ages ranging from 3 to 27 months. Serum T levels were controlled by subcutaneous implantation of different sizes of T-filled Silastic capsules at the time of castration. In intact male rats, scores of various parameters of copulatory behavior declined gradually from middle age and no ejaculation was observed in any rats over 22 months of age. When serum T levels were maintained at 0.78-0.87 ng/ml for 6 months from 4 months of age, these rats showed the same copulatory activity as intact rats, except that fewer rats exhibited ejaculation at 8 and 10 months of age and showed decreased total mount frequency at 10 months of age. Even when serum T levels were maintained at 2.95-3.53 ng/ml for a period of 6 months from 18 months of age, copulatory activity still declined gradually and no rats over 22 months of age ejaculated. However, long-term elevation of serum T level could prevent further decline of intromission frequency in old age. These results indicate that the copulatory activity of male rats in response to circulatory T declined with advancing age and that prolonged low levels of serum T had only a minor role in the onset of decreased responsiveness of neural male sexual behavior.

Aging↗
PubMed1986

Reappraisal of empyema thoracis. Surgical intervention when the duration of illness is unknown.

The timing of surgical treatment of empyema remains controversial. Traditionally, thoracotomy is performed either within three weeks of diagnosis or delayed until presumed pleurodesis occurs. Often, these patients are moribund and the duration of illness impossible to determine. We report our surgical results in seven patients with a deteriorating clinical course and multiple loculations which persisted after tube thoracostomy and would not have responded to multiple thoracostomies. Five patients required decortication. One required lobectomy for an abscess which developed on the contralateral side six weeks after discharge. There were no deaths or recurrences of empyema. Average times from surgery to tube removal and to discharge were six to 12 days, respectively. We conclude that one can safely and cost-effectively treat these patients surgically even when the duration of illness and presence of pleurodesis are unknown, and that the postoperative course will be uncomplicated.

Adult↗