Role of apoptosis induction in both peripheral lymph nodes and thymus in progressive loss of CD4+ cells in SHIV-infected macaques

To investigate the role of apoptosis in the progressive loss of CD4+ lymphocytes in HIV infection, we have used macaques infected with SHIV, a hybrid virus of HIV and simian immunodeficiency virus (SIV). In the present study, we sequentially analyzed apoptosis induction in the acute phase of SHIV infection. Four macaques infected with a pathogenic SHIV, SHIV89.6P, and four macaques infected with a nonpathogenic SHIV, NM-3rN, were analyzed during the first 2 or 4 weeks postinfection. In the 89.6P-infected macaques the number of peripheral CD4+ cells sharply decreased at 2 weeks postinfection and was maintained below 50/microl until 4 weeks postinfection, while in the NM-3rN-infected macques the number of the CD4+ cells did not change significantly. Plasma viral loads peaked at 2 and 2-3 weeks postinfection, and the peak values were about 1 x 10(9) and 10(6)-10(7) copies/ml in the 89.6P- and the NM-3rN-infected macaques, respectively. In the 89.6P-infected macaques, Fas antigen expression and the extent of apoptosis in PBMCs and peripheral lymph nodes increased at 1-2 weeks postinfection. A high number of apoptotic cells was also observed in thymus sections 2 and 4 weeks postinfection. On the other hand, apoptosis was scarcely induced in the NM-3rN-infected macaques. These results suggest that the extent of apoptosis induction is closely correlated with the pathogenicity of SHIV and that the apoptosis induction in peripheral lymphoid tissues and thymus, where T cell maturation occurs, may play an important role in the depletion of CD4+ lymphocytes in 89.6P infection.

Protective immunity of gene-deleted SHIVs having an HIV-1 Env against challenge infection with a gene-intact SHIV

We constructed three simian-human immunodeficiency viruses (SHIVs) lacking regulatory gene(s) and analyzed their induction of protective immunity against challenge infection with gene-intact SHIV in rhesus macaques. Inoculation of SHIV-dn lacking nef and SHIV-drn lacking nef and vpr induced transient viremia, while that of SHIV-dxrn lacking nef, vpr, and vpx induced no viremia. The SHIVs with fewer deletions were more effective in inducing neutralizing antibodies and cytotoxic T lymphocyte responses. When these macaques were challenged with parental gene-intact SHIV-NM-3rN, all the SHIV-dn-vaccinated macaques and two of the four SHIV-drn-vaccinated macaques showed complete resistance. The other two SHIV-drn-vaccinated macaques and all SHIV-dxrn-vaccinated macaques did not show complete resistance, but they did show suppression of replication of the challenge virus. These results suggested that as more genes were deleted, protective immunity was decreased.

Replication capacity of simian immunodeficiency virus in cultured macaque macrophages and dendritic cells is not prerequisite for intravaginal transmission of the virus in macaques

In order to test the hypothesis that macrophages and dendritic cells (DCs) in mucosal tissue play an important role in heterosexual transmission of human immunodeficiency virus, the replication capacities of two simian immunodeficiency viruses (SIVs) were examined in cultured macrophages and DCs as well as in cultured PBMCs in vitro. The virus strains were a T cell-tropic SIV, SIVmac239, and a T cell- and macrophage-tropic (dual-tropic) SIV, SIVmac239/316E. The infectivities of these viruses to cynomolgus macaques by intravaginal inoculation were also compared. Although both virus strains replicated well in cultured PBMCs, SIVmac239 did not replicate in cultured macrophages, whereas SIVmac239/316E did. Both strains showed little replication in cultured DCs, but a high virus yield could be obtained when SIVmac239/316E-infected DCs were co-cultured with uninfected PBMCs. A mixture of these SIVs was inoculated intravaginally to three monkeys and the virus strain that first appeared through the vaginal mucosa was determined. The virus clones detected first in PBMCs, inguinal lymph nodes and vaginal wash cells (VWCs) after the virus inoculation were of SIVmac239 in all cases, except for one clone of SIVmac239/316E in VWCs of one monkey at one time-point. These results show that the infectivity of the virus in intravaginal transmission did not depend on the cell tropism in vitro of the virus.

A comparison of vascularized and conventional sural nerve grafts

Long-term results of a randomized series of 27 vascularized and 22 conventional sural nerve grafts in patients with comparable upper extremity injuries are reported. Recovery speed and outcome depended on (1) whether or not there was an overlying skin defect, (2) how the defect was closed, and (3) which nerve was injured and at what level. Generally, a vascularized nerve graft is indicated when the nerve gap is more than 6 cm and is associated with a massive skin defect or the graft is performed after reimplantation. Otherwise, results achieved with a conventional graft are equally good.

Falling among the sensorially impaired elderly

Recent studies of the healthy elderly indicate that accidental falls account for many lengthy hospital stays and permanent disabilities. An ongoing investigation by our group is examining the contribution of neuromuscular feedback and the possible substitution of visual-perceptual feedback as a major contributor to falling in this population. This combination of decreased weighting of neuromuscular factors and increased weighting of the visual-perceptual factors led to the following hypothesis: Those persons who cannot see should show less change in frequency of falling as they age than sighted cohorts. The deaf, who rely more than others on visual perceptual stimuli, are less likely to fall as they age than the general elderly population, who first begin to rely more heavily on visual stimuli when they age. Thus, the deaf and blind constitute a population whose change in frequency of falls with increased age should differ markedly from change in the frequency of falls among the nonblind and nondeaf segments of the population. Our results support the hypothesis. The blind demonstrated a higher rate of falls than the deaf or nonimpaired population. However, the more elderly blind failed to show the increase in falling demonstrated by the deaf and nonimpaired. If these findings are confirmed in subsequent studies, the nonimpaired and deaf elderly could be trained to focus on visual feedback. The blind may be able to reduce the frequency of falls by enhancing musculoskeletal feedback and strength via exercise.

A patient with Graves' disease who developed hypothyroidism associated with thyroid stimulation blocking immunoglobulin during anti-thyroid drug therapy

A girl, 12 years of age, developed Graves' disease compounded with rheumatic fever and idiopathic thrombocytopenic purpura. Thrombocytopenia improved under short-term treatment with steroids and her mitral valvular insufficiency, due to the rheumatic fever, disappeared 4 years later. Initially, she had been treated with propylthiouracil (PTU) for 28 months. She suffered a relapse 9 months after stopping PTU and so she was given further PTU therapy. However, hypothyroidism developed 11 months after the initiation of therapy and continued, though further PTU treatment was discontinued. She now receives 1-thyroxine and maintains a euthyroid state. At the onset of the patient's hyperthyroidism, the TSH-binding inhibitor immunoglobulin (TBII) and the thyroid stimulating antibodies (TSAb) were found to be positive. During the remission period, only the thyroid stimulation blocking immunoglobulin (TSBI) was weakly positive. At relapse, only TBII was mildly positive. When hypothyroidism developed, both TBII and TSBI were positive, and TSAb was negative in all testings of her diluted IgGs. The patient's TBII and thyroid dysfunction were unaffected by high-dose intravenous gammaglobulin therapy or by treatment with prednisolone 0.5 mg/kg/day for 2 weeks. In conclusion, the emergence of TSBI during or after anti-thyroid drug therapy might possibly lead to hypothyroidism in patients with Graves' disease.

A reliable technique of free vascularized sural nerve grafting and preliminary results of clinical applications

A technique of harvesting a free vascularized sural nerve graft based on either the cutaneous branch of the peroneal artery or the muscular perforating branch of the posterior tibial artery is described. Anatomic dissections with dye injection studies confirmed the reliability of this blood supply to a 25 cm long segment of the sural nerve. The sural nerve can be sectioned into as many as four segments while safely maintaining each segment's vascularity through intact fascia. A skin monitor can be elevated with the nerve to monitor vascular patency. The free vascularized sural nerve was used to reconstruct 16 nerve defects in the upper extremity. All 13 skin monitors elevated have survived. Early follow-up (range, 2 to 31 months) has shown encouraging clinical recovery. Although our preliminary results are difficult to compare with other series, this technique appears promising in clinical circumstances when interfascicular nerve grafting is indicated but the recipient bed is heavily scarred and poorly vascularized.

Relationship between potency of blocking type thyrotropin-binding inhibitor immunoglobulin in three women with primary myxedema and thyroid function of their neonates

Three neonates born to three mothers with primary myxedema who have thyrotropin-binding inhibitor immunoglobulin (TBII) were continually examined after birth. One neonate showed a high TSH level in mass-screening for congenital hypothyroidism and developed transient hypothyroidism. Her TBII disappeared at 114 days of age, and she remained euthyroid after discontinuation of thyroxin replacement at 146 days of age. The other two neonates were euthyroid, though they had positive TBII. In three mothers, the doses of IgGs that inhibited 125I-TSH binding to the level of 50% were compared. The potency of IgG from the mother whose neonate developed hypothyroidism was stronger than that of IgG from the other two mothers. And the elevation of cAMP induced by bovine TSH in suspension culture with porcine thyroid follicles was significantly reduced in the presence of IgG from the three mothers when compared with normal IgG. The thyroid-stimulation blocking activity was more potent in the mother whose neonate developed hypothyroidism than in the other two mothers. This study suggests that the thyroid function of neonates born to primary myxedema with blocking type TBII is influenced by the potency of TSH-binding inhibitor and thyroid-stimulation blocking activity of the mother.

[Effects of oxybutynin hydrochloride on the urinary bladder and urethra in in situ preparations]

Effects of oxybutynin on the urinary bladder and urethra were studied in comparison with atropine and flavoxate in cats and rabbits. Oxybutynin at 10 mg/kg, i.v., significantly inhibited the bladder contractions induced by electrical stimulation of the peripheral end in pelvic nerve. Oxybutynin was about one half the potency of atropine. On the contrary, 10 mg/kg of flavoxate, i.v., showed both effects of potentiation and inhibition. The bladder contractions induced by acetylcholine (ACh) and AHR-602 were markedly inhibited by oxybutynin and atropine. Oxybutynin was about one-fifteenth the potency of atropine. DMPP-induced contractions were inhibited by oxybutynin and atropine in a high dose, but oxybutynin was about two-fifths the potency of atropine. In addition, 3 mg/kg of oxybutynin, i.v., inhibited the contraction induced by hypogastric nerve stimulation, but 10 mg/kg of oxybutynin, i.v., significantly inhibited this contraction following initial potentiation. Oxybutynin showed an inhibitory effect on spontaneous rhythmical contraction, bladder tone and pelvic nerve discharge, similar to the effects of atropine. On the contrary, flavoxate potentiated this contraction and increased the bladder tone and pelvic and hypogastric nerve discharge. Urethra contractions induced by norepinephrine, ACh and hypogastric nerve stimulation were inhibited by oxybutynin, but not markedly. Oxybutynin and atropine dose-dependently increased the infusion volume, bladder volume capacity and micturition threshold pressure in the cystometrogram in rabbits. Flavoxate also increased them. From these results, it si suggested that oxybutynin is therapeutically a useful agent for pollakisurea nervosa.

The free vascularized sural nerve graft

The sural nerve was described as a new donor nerve of the free vascularized nerve graft in a fresh cadaver's dissection and in four clinical cases. The vascularized sural nerve is nourished by the cutaneous branch of the peroneal artery or the muscular perforating branch of the posterior tibial artery in our grafts. Compared to other vascularized nerve grafts, the sural nerve has many advantages: 1) A "two- or three-fold nerve graft" can be designed on itself without damage to the blood supply of the nerve, 2) survival of the nerve can be reasoned by the accompanying flap and the flap can close the skin defect simultaneously without additional vascular anastomosis, and 3) sensory loss at the donor site is negligible. The final extent of sensory recovery in our clinical cases could require several months, but a quickly advanced Tinel's sign suggested the technique's superiority.